Sample records for holes time frame

  1. On Space-Time Singularities, Holes, and Extensions

    E-Print Network [OSTI]

    Manchak, John

    On Space-Time Singularities, Holes, and Extensions John Byron Manchak*y Here, we clarify the relationship among three space-time conditions of interest: geodesic completeness, hole. In what follows, we consider three space-time conditions of interest: geodesic completeness, hole

  2. Examining the Variability of Wind Power Output in the Regulation Time Frame: Preprint

    SciTech Connect (OSTI)

    Hodge, B. M.; Shedd, S.; Florita, A.


    This work examines the distribution of changes in wind power for different time scales in the regulation time frame as well as the correlation of changes in power output for individual wind turbines in a wind plant.

  3. Real-Time Frame-Dependent Watermarking in MPEG-2 Video

    E-Print Network [OSTI]

    Chen, Sheng-Wei

    Real-Time Frame-Dependent Watermarking in MPEG-2 Video Chun-Shien Lu ?, Jan-Ru Chen y, and Kuo data. In particular, video watermarking deals with several issues that are unique to various types-time detection, bit-rate control, and resistance to watermark estimation attacks, will be addressed. Since video

  4. Distinguishing causal time from Minkowski time and a model for the black hole quantum eigenstates

    E-Print Network [OSTI]

    G. 't Hooft


    A discussion is presented of the principle of black hole com- plementarity. It is argued that this principle could be viewed as a breakdown of general relativity, or alternatively, as the introduction of a time variable with multiple `sheets' or `branches' A consequence of the theory is that the stress-energy tensor as viewed by an outside observer is not simply the Lorentz-transform of the tensor viewed by an ingoing observer. This can serve as a justification of a new model for the black hole atmosphere, recently re-introduced. It is discussed how such a model may lead to a dynamical description of the black hole quantum states.

  5. Microsecond time-scale dynamics from relaxation in the rotating frame: experiments using spin lock with alternating phase

    E-Print Network [OSTI]

    Skrynnikov, Nikolai

    be made that 180° pulses refocus the chemical shift evolution and thus prevent the build-up of randomlyMicrosecond time-scale dynamics from relaxation in the rotating frame: experiments using spin lockÞðÀxÞðxÞðÀxÞ . . ., is proposed as a new technique to probe microsecond time-scale dynamics. A series of R1q measurements using

  6. Holographic Space-time and Black Holes: Mirages As Alternate Reality

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler; Sandipan Kundu; Juan F. Pedraza


    We revisit our investigation of the claim of [1] that old black holes contain a firewall, i.e. an in-falling observer encounters highly excited states at a time much shorter than the light crossing time of the Schwarzschild radius. We used the formalism of Holographic Space-time (HST) where there is no dramatic change in particle physics inside the horizon until a time of order the Schwarzschild radius. We correct our description of the interior of the black hole . HST provides a complete description of the quantum mechanics along any time-like trajectory, even those which fall through the black hole horizon. The latter are described as alternative factorizations of the description of an external observer, turning the mirage of the interior provided by that observer's membrane paradigm on the stretched horizon, into reality.

  7. Parallel and real-time implementation of an acoustic echo canceller using oversampled wavelet frame algorithms

    E-Print Network [OSTI]

    Tam, Pak-Yin


    This thesis describes a novel echo cancellation system that eliminates nonstationary echoes with long acoustic delays in real-time. By combining subband adaptive filtering and active system identification based on fast wavelet transform...

  8. Kerr black holes and time profiles of gamma-ray bursts

    E-Print Network [OSTI]

    S. McBreen; B. McBreen; L. Hanlon; F. Quilligan


    The cumulative light curves of gamma-ray bursts (GRBs) smooth the spiky nature of the running light curve. The cumulative count increases in an approximately linear way with time t for most bursts. In 19 out of 398 GRBs with T90 > 2s, the cumulative light curve was found to increase with time as \\~t^2 implying a linear increase in the running light curve. The non-linear sections last for a substantial fraction of the GRB duration, have a large proportion of the cumulative count and many resolved pulses that usually end with the highest pulse in the burst. The reverse behaviour was found in 11 GRBs where the running light curve decreased with time and some bursts are good mirror images of the increases. These GRBs are among the spectrally hardest bursts observed by BATSE. The most likely interpretation is that these effects are signatures of black holes that are either being spun up or down in the accretion process. In the spin up case, the increasing Kerr parameter of the black hole allows additional rotational and accretion energy to become available for extraction. The process is reversed if the black hole is spun down by magnetic field torques. The luminosity changes in GRBs are consistent with the predictions of the BZ process and neutrino annihilation and thus provide the link to spinning black holes. GRBs provide a new window for studying the general relativistic effects of Kerr black holes.

  9. Time-dependent models of two-phase accretion discs around black holes

    E-Print Network [OSTI]

    M. Mayer; J. E. Pringle


    We present time-dependent simulations of a two-phase accretion flow around a black hole. The accretion flow initially is composed of an optically thick and cool disc close to the midplane, while on top and below the disc there is a hot and optically thin corona. We consider several interaction mechanisms as heating of the disc by the corona and Compton cooling of the corona by the soft photons of the disc. Mass and energy can be exchanged between the disc and the corona due to thermal conduction. For the course of this more exploratory work, we limit ourselves to one particular model for a stellar mass black hole accreting at a low accretion rate. We confirm earlier both theoretical and observational results which show that at low accretion rates the disc close to the black hole cannot survive and is evaporated. Given the framework of this model, we now can follow through this phase of disc evaporation time dependently.

  10. Studying accreting black holes and neutron stars with time series: beyond the power spectrum

    E-Print Network [OSTI]

    S. Vaughan; P. Uttley


    The fluctuating brightness of cosmic X-ray sources, particularly accreting black holes and neutron star systems, has enabled enormous progress in understanding the physics of turbulent accretion flows, the behaviour of matter on the surfaces of neutron stars and improving the evidence for black holes. Most of this progress has been made by analysing and modelling time series data in terms of their power and cross spectra, as will be discussed in other articles in this volume. Recently, attempts have been made to make use of other aspects of the data, by testing for non-linearity, non-Gaussianity, time asymmetry and by examination of higher order Fourier spectra. These projects, which have been made possible by the vast increase in data quality and quantity over the past decade, are the subject of this article.

  11. The Energy Distribution in a Static Spherically Symmetric Nonsingular Black Hole Space-Time

    E-Print Network [OSTI]

    I. Radinschi


    We calculate the energy distribution in a static spherically symmetric nonsingular black hole space-time by using the Tolman's energy-momentum complex. All the calculations are performed in quasi-Cartesian coordinates. The energy distribution is positive everywhere and be equal to zero at origin. We get the same result as obtained by Y-Ching Yang by using the Einstein's and Weinberg's prescriptions.

  12. Quantum time uncertainty in Schwarzschild-anti-de Sitter black holes

    SciTech Connect (OSTI)

    Galan, Pablo; Mena Marugan, Guillermo A. [Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain); Garay, Luis J. [Departamento de Fisica Teorica II, Universidad Complutense de Madrid, 28040 Madrid (Spain); Instituto de Estructura de la Materia, CSIC, Serrano 121, 28006 Madrid (Spain)


    The combined action of gravity and quantum mechanics gives rise to a minimum time uncertainty in the lowest order approximation of a perturbative scheme, in which quantum effects are regarded as corrections to the classical spacetime geometry. From the nonperturbative point of view, both gravity and quantum mechanics are treated on equal footing in a description that already contains all possible backreaction effects as those above in a nonlinear manner. In this paper, the existence or not of such minimum time uncertainty is analyzed in the context of Schwarzschild-anti-de Sitter black holes using the isolated horizon formalism. We show that from a perturbative point of view, a nonzero time uncertainty is generically present owing to the energy scale introduced by the cosmological constant, while in a quantization scheme that includes nonperturbatively the effects of that scale, an arbitrarily high time resolution can be reached.

  13. Real-time solar wind prediction based on SDO/AIA coronal hole data

    E-Print Network [OSTI]

    Rotter, T; Temmer, M; Vrsnak, B


    We present an empirical model based on the visible area covered by coronal holes close to the central meridian in order to predict the solar wind speed at 1 AU with a lead time up to four days in advance with a 1hr time resolution. Linear prediction functions are used to relate coronal hole areas to solar wind speed. The function parameters are automatically adapted by using the information from the previous 3 Carrington Rotations. Thus the algorithm automatically reacts on the changes of the solar wind speed during different phases of the solar cycle. The adaptive algorithm has been applied to and tested on SDO/AIA-193A observations and ACE measurements during the years 2011-2013, covering 41 Carrington Rotations. The solar wind speed arrival time is delayed and needs on average 4.02 +/- 0.5 days to reach Earth. The algorithm produces good predictions for the 156 solar wind high speed streams peak amplitudes with correlation coefficients of cc~0.60. For 80% of the peaks, the predicted arrival matches within ...

  14. Simulation of Water Level Fluctuations in Kettle Holes Using a Time Series Model

    E-Print Network [OSTI]

    Kleyer, Michael

    online: 21 April 2011 # Society of Wetland Scientists 2011 Abstract Kettle holes are widespread in the future, conservation strategies for kettle holes should include the effects of climate change. Keywords). This number is comparable with the wetland loss in the United States (Dahl 1990; Johnston 1994), Japan

  15. A Woman Framed

    E-Print Network [OSTI]

    Allison, Mary Ann


    are changing. Allison, Mary Ann. “A Woman Framed”. http://21: 60- 64 ISSN: 2159-2926 A Woman Framed Mary Ann AllisonAllison, Mary Ann. “A Woman Framed”. http://

  16. Solar/hydrogen systems for the 1985 to 2000 time frame. Volume I. Solar/hydrogen systems assessment. Final report

    SciTech Connect (OSTI)

    Foster, R. W.; Tison, R. R.; Escher, W. J.D.; Hanson, J. A.


    The findings of a study of opportunities for commercialization of systems capable of producing hydrogen from solar energy are presented in two volumes. A compendium of monographs by specialists in the fields of solar energy conversion technologies, hydrogen production technologies and related technology descriptions from the general literature comprise Volume II. This data base was used to support an evaluation and selection process that identified four candidate solar/hydrogen systems best suited to commercialization within the next two decades. Volume I first reviews the background of the work and the methods used. Then an evaluation of the hydrogen product costs that might be achieved by the four selected candidate systems (photovoltaic/water electrolysis, thermal-heat engine/water electrolysis, wind energy/water electrolysis, small hydrogen/water electrolysis) is compared with the pricing structure and practices of the commodity gas market. Subsequently, product cost and market price match is noted to exist in the small user sector of the hydrogen marketplace. Barriers to and historical time lags in, commercialization of new technologies are then reviewed. Finally, recommendations for development and demonstration programs designed to accelerate the commercialization of the candidate systems are presented.

  17. Energy-Momentum Localization for a Space-Time Geometry Exterior to a Black Hole in the Brane World

    E-Print Network [OSTI]

    Irina Radinschi; Theophanes Grammenos; Andromahi Spanou


    In general relativity one of the most fundamental issues consists in defining a generally acceptable definition for the energy-momentum density. As a consequence, many coordinate-dependent definitions have been presented, whereby some of them utilize appropriate energy-momentum complexes. We investigate the energy-momentum distribution for a metric exterior to a spherically symmetric black hole in the brane world by applying the Landau-Lifshitz and Weinberg prescriptions. In both the aforesaid prescriptions, the energy thus obtained depends on the radial coordinate, the mass of the black hole and a parameter $\\lambda_{0}$, while all the momenta are found to be zero. It is shown that for a special value of the parameter $\\lambda_{0}$, the Schwarzschild space-time geometry is recovered. Some particular and limiting cases are also discussed.

  18. Stability of Gauss-Bonnet black holes in anti-de Sitter space-time against scalar field condensation

    SciTech Connect (OSTI)

    Brihaye, Yves [Physique-Mathematique, Universite de Mons-Hainaut, 7000 Mons (Belgium); Hartmann, Betti [School of Engineering and Science, Jacobs University Bremen, 28759 Bremen (Germany)


    We study the stability of static, hyperbolic Gauss-Bonnet black holes in (4+1)-dimensional anti-de Sitter (AdS) space-time against the formation of scalar hair. Close to extremality the black holes possess a near-horizon topology of AdS{sub 2}xH{sup 3} such that within a certain range of the scalar field mass one would expect that they become unstable to the condensation of an uncharged scalar field. We confirm this numerically and observe that there exists a family of hairy black hole solutions labeled by the number of nodes of the scalar field function. We construct explicit examples of solutions with a scalar field that possesses zero nodes, one node, and two nodes, respectively, and show that the solutions with nodes persist in the limit of Einstein gravity, i.e. for vanishing Gauss-Bonnet coupling. We observe that the interval of the mass for which scalar field condensation appears decreases with increasing Gauss-Bonnet coupling and/or with increasing node number.

  19. Frame-Semantic Parsing

    E-Print Network [OSTI]

    Das, Dipanjan

    Frame semantics is a linguistic theory that has been instantiated for English in the FrameNet lexicon. We solve the problem of frame-semantic parsing using a two-stage statistical model that takes lexical targets (i.e., ...

  20. Late-Time Dynamics of Scalar Fields on Rotating Black Hole Backgrounds

    E-Print Network [OSTI]

    William Krivan


    Motivated by results of recent analytic studies, we present a numerical investigation of the late-time dynamics of scalar test fields on Kerr backgrounds. We pay particular attention to the issue of mixing of different multipoles and their fall-off behavior at late times. Confining ourselves to the special case of axisymmetric modes with equatorial symmetry, we show that, in agreement with the results of previous work, the late-time behavior is dominated by the lowest allowed l-multipole. However the numerical results imply that, in general, the late-time fall-off of the dominating multipole is different from that in the Schwarzschild case, and seems to be incompatible with a result of a recently published analytic study.

  1. Resources, framing, and transfer p. 1 Resources, framing, and transfer

    E-Print Network [OSTI]

    Hammer, David

    Resources, framing, and transfer p. 1 Resources, framing, and transfer David Hammer Departments. #12;Resources, framing, and transfer p. 2 Resources, framing, and transfer David Hammer, Andrew Elby of activating resources, a language with an explicitly manifold view of cognitive structure. In this chapter, we

  2. Investigating a Fluctuating-accretion Model for the Spectral-timing Properties of Accreting Black Hole Systems

    E-Print Network [OSTI]

    P. Arevalo; P. Uttley


    The fluctuating accretion model of Lyubarskii (1997) and its extension by Kotov et al. (2001), seeks to explain the spectral-timing properties of the X-ray variability of accreting black holes in terms of inward-propagating mass accretion fluctuations produced at a broad range of radii. The fluctuations modulate the X-ray emitting region as they move inwards and can produce temporal-frequency-dependent lags between energy bands, and energy-dependent power spectral densities (PSDs) as a result of the different emissivity profiles, which may be expected at different X-ray energies. Here we use a simple numerical implementation to investigate in detail the X-ray spectral-timing properties of the model and their relation to several physically interesting parameters, namely the emissivity profile in different energy bands, the geometrical thickness and viscosity parameter of the accretion flow, the strength of damping on the fluctuations and the temporal coherence (measured by the `quality-factor', Q) of the fluctuations introduced at each radius. We find that a geometrically thick flow with large viscosity parameter is favoured, and confirm that the predicted lags are quite robust to changes in the emissivity profile, and physical parameters of the accretion flow, which may help to explain the similarity of the lag spectra in the low/hard and high/soft states of Cyg X-1. We also demonstrate the model regime where the light curves in different energy bands are highly spectrally coherent. We compare model predictions directly to X-ray data from the Narrow Line Seyfert~1 galaxy NGC 4051 and the BHXRB Cyg X-1 in its high/soft state and show that this general scheme can reproduce simultaneously the time lags and energy-dependence of the PSD.

  3. Timing and Spectral Properties of X-ray Emission from the Converging Flows onto Black hole: Monte-Carlo Simulations

    E-Print Network [OSTI]

    Philippe Laurent; Lev Titarchuk


    We demonstrate that a X-ray spectrum of a converging inflow (CI) onto a black hole is the sum of a thermal (disk) component and the convolution of some fraction of this component with the Comptonization spread (Green's) function. The latter component is seen as an extended power law at energies much higher than the characteristic energy of the soft photons. We show that the high energy photon production (source function) in the CI atmosphere is distributed with the characteristic maximum at about the photon bending radius, 1.5r_S, independently of the seed (soft) photon distribution. We show that high frequency oscillations of the soft photon source in this region lead to the oscillations of the high energy part of the spectrum but not of the thermal component. The high frequency oscillations of the inner region are not significant in the thermal component of the spectrum. We further demonstrate that Doppler and recoil effects (which are responsible for the formation of the CI spectrum) are related to the hard (positive) and soft (negative) time lags between the soft and hard photon energy channels respectively.

  4. Causal equivalence of frames

    E-Print Network [OSTI]

    Henderson, Troy Lee, IV


    Major Subject: Mathematics August 2005 DOCTOR OF PHILOSOPHY in partial fulfillment of the requirements for the degree of Texas A&M University Submitted to the Office of Graduate Studies of TROY LEE HENDERSON, IV by A Dissertation CAUSAL EQUIVALENCE... to the Office of Graduate Studies of TROY LEE HENDERSON, IV by A Dissertation CAUSAL EQUIVALENCE OF FRAMES iii ABSTRACT Causal Equivalence of Frames. (August 2005) Troy Lee Henderson, IV, B.S., The University of Alabama; M.A., The University of Alabama Chair...

  5. ATF Video Frame Grabber Subsystems - Frequently Asked Questions

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    While rare, unexpected AC power problems, frame grabber hardware failures, etc. can render your hard-earned data corrupted or completely unreadable. Take the time to save your...

  6. Surgery on frames

    E-Print Network [OSTI]

    Nguyen, Nga Quynh


    >q) . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. The tight unit norm expansion problem (The case pFrames...

  7. Tunneling into black hole, escape from black hole, reflection from horizon and pair creation

    E-Print Network [OSTI]

    V. V. Flambaum


    Within classical general relativity, a particle cannot reach the horizon of a black hole during a finite time, in the reference frame of an external observer; a particle inside cannot escape from a black hole; and the horizon does not produce any reflection. We argue that these processes may possibly be allowed in the quantum world. It is known that quantum mechanics allows pair creation at the horizon (one particle inside, another particle outside) and Hawking radiation. One can extend this idea to propose other processes. Tunneling of an external particle inside black hole may be produced by the creation of a pair at the horizon, followed by the annihilation of one created particle with the initial particle outside, with the other created particle appearing inside. Escape of a particle from a black hole may result from the creation of a pair, followed by the annihilation of one created particle with the particle inside, with the other created particle appearing outside. The escape may allow the transfer of information to the outside.Finally, the reflection of an external particle from the horizon may be modelled by a combination of the two processes presented above. The relationship between these "pair creation-annihilation'' mechanisms and the "horizon tunneling" calculations [1-5] is discussed.

  8. Conformal Frame Dependence of Inflation

    E-Print Network [OSTI]

    Domènech, Guillem


    Physical equivalence between different conformal frames in scalar-tensor theory of gravity is a known fact. However, assuming that matter minimally couples to the metric of a particular frame, which we call the matter Jordan frame, the matter point of view of the universe may vary from frame to frame. Thus, there is a clear distinction between gravitational sector (curvature and scalar field) and matter sector. In this paper, focusing on a simple power-law inflation model in the Einstein frame, two examples are considered; a super-inflationary and a bouncing universe Jordan frames. Then we consider a spectator curvaton minimally coupled to a Jordan frame, and compute its contribution to the curvature perturbation power spectrum. In these specific examples, we find a blue tilt at short scales for the super-inflationary case, and a blue tilt at large scales for the bouncing case.

  9. High Performance Commercial Fenestration Framing Systems

    SciTech Connect (OSTI)

    Mike Manteghi; Sneh Kumar; Joshua Early; Bhaskar Adusumalli


    A major objective of the U.S. Department of Energy is to have a zero energy commercial building by the year 2025. Windows have a major influence on the energy performance of the building envelope as they control over 55% of building energy load, and represent one important area where technologies can be developed to save energy. Aluminum framing systems are used in over 80% of commercial fenestration products (i.e. windows, curtain walls, store fronts, etc.). Aluminum framing systems are often required in commercial buildings because of their inherent good structural properties and long service life, which is required from commercial and architectural frames. At the same time, they are lightweight and durable, requiring very little maintenance, and offer design flexibility. An additional benefit of aluminum framing systems is their relatively low cost and easy manufacturability. Aluminum, being an easily recyclable material, also offers sustainable features. However, from energy efficiency point of view, aluminum frames have lower thermal performance due to the very high thermal conductivity of aluminum. Fenestration systems constructed of aluminum alloys therefore have lower performance in terms of being effective barrier to energy transfer (heat loss or gain). Despite the lower energy performance, aluminum is the choice material for commercial framing systems and dominates the commercial/architectural fenestration market because of the reasons mentioned above. In addition, there is no other cost effective and energy efficient replacement material available to take place of aluminum in the commercial/architectural market. Hence it is imperative to improve the performance of aluminum framing system to improve the energy performance of commercial fenestration system and in turn reduce the energy consumption of commercial building and achieve zero energy building by 2025. The objective of this project was to develop high performance, energy efficient commercial fenestration framing systems, by investigating new technologies that would improve the thermal performance of aluminum frames, while maintaining their structural and life-cycle performance. The project targeted an improvement of over 30% (whole window performance) over conventional commercial framing technology by improving the performance of commercial framing systems.


    SciTech Connect (OSTI)

    Sanfilippo, Antonio P.; McGrath, Liam R.; Whitney, Paul D.


    We present a computational approach to radical rhetoric that leverages the co-expression of rhetoric and action features in discourse to identify violent intent. The approach combines text mining and machine learning techniques with insights from Frame Analysis and theories that explain the emergence of violence in terms of moral disengagement, the violation of sacred values and social isolation in order to build computational models that identify messages from terrorist sources and estimate their proximity to an attack. We discuss a specific application of this approach to a body of documents from and about radical and terrorist groups in the Middle East and present the results achieved.

  11. Black Holes

    E-Print Network [OSTI]

    P. K. Townsend


    Lecture notes for a 'Part III' course 'Black Holes' given in DAMTP, Cambridge. The course covers some of the developments in Black Hole physics of the 1960s and 1970s.

  12. Selection of Long-Term Reference Frames in Dual-Frame Video Coding Using Simulated Annealing

    E-Print Network [OSTI]

    Tiwari, M.; Cosman, P. C.


    Index Terms—Dual-frame video coding, long-term reference frame, simulated annealing, video compression.

  13. Inertial Frames and Clock Rates

    E-Print Network [OSTI]

    Subhash Kak


    This article revisits the historiography of the problem of inertial frames. Specifically, the case of the twins in the clock paradox is considered to see that some resolutions implicitly assume inertiality for the non-accelerating twin. If inertial frames are explicitly identified by motion with respect to the large scale structure of the universe, it makes it possible to consider the relative inertiality of different frames.

  14. Einstein's lost frame Rodrigo de Abreu and Vasco Guerra

    E-Print Network [OSTI]

    Guerra, Vasco

    Einstein's lost frame Rodrigo de Abreu and Vasco Guerra November 24, 2005 #12;2 #12;Contents 1 Introduction 7 2 Einstein's frame 15 2.1 Space and time . . . . . . . . . . . . . . . . . . . . . . . . . . 15 and Einstein . . . . . . . . . . . . . . . . . . 57 4.2 A formal Galileo transformation

  15. Contrast from rotating frame relaxation by adiabatic pulses

    DOE Patents [OSTI]

    Michaeli, Shalom (St. Paul, MN); Garwood, Michael G. (Medina, MN); Ugurbil, Kamil (Minneapolis, MN); Sorce, Dennis J. (Cockeysville, MD)


    This document discusses, among other things, a system and method for modulating transverse and longitudinal relaxation time contrast in a rotating frame based on a train of radio frequency pulses.

  16. Hyperbolic Equations for Vacuum Gravity Using Special Orthonormal Frames

    E-Print Network [OSTI]

    Frank B. Estabrook; R. Steve Robinson; Hugo D. Wahlquist


    By adopting Nester's higher dimensional special orthonormal frames (HSOF) the tetrad equations for vacuum gravity are put into first order symmetric hyperbolic (FOSH) form with constant coefficients, independent of any time slicing or coordinate specialization.

  17. The Frame Potential, on Average

    E-Print Network [OSTI]

    Ingemar Bengtsson; Helena Granstrom


    A SIC consists of N^2 equiangular unit vectors in an N dimensional Hilbert space. The frame potential is a function of N^2 unit vectors. It has a unique global minimum if the vectors form a SIC, and this property has been made use of in numerical searches for SICs. When the vectors form an orbit of the Heisenberg group the frame potential becomes a function of a single fiducial vector. We analytically compute the average of this function over Hilbert space. We also compute averages when the fiducial vector is placed in certain special subspaces defined by the Clifford group.

  18. Physics 321 Accelerating Reference Frames II

    E-Print Network [OSTI]

    Hart, Gus

    Physics 321 Hour 25 Accelerating Reference Frames II Consider an accelerating train car Proof 0 and S is a frame rotating with angular velocity . Examples Handout rotation.nb #12;Physics 321 Hour 26 Accelerating Reference Frames III Velocities in Rotating Frames in S0 basis in S' basis In S' basis in S0 basis

  19. Threshold bracing stiffness of two story frames

    E-Print Network [OSTI]

    Khader, Ghassan Sudki


    and lateral stability achieved in the pin jointed frame shown in Fig. 11(a). 30 Numerical Example for the Pin Jointed Frame The variation of Kt with Ks is demonstrated by considering the pin jointed frame shown in Fig. 11(a). The frame geometry and member...

  20. Black hole accretion discs

    E-Print Network [OSTI]

    Lasota, Jean-Pierre


    This is an introduction to models of accretion discs around black holes. After a presentation of the non-relativistic equations describing the structure and evolution of geometrically thin accretion discs we discuss their steady-state solutions and compare them to observation. Next we describe in detail the thermal-viscous disc instability model and its application to dwarf novae for which it was designed and its X-ray irradiated-disc version which explains the soft X--ray transients, i.e. outbursting black-hole low-mass X-ray binaries. We then turn to the role of advection in accretion flow onto black holes illustrating its action and importance with a toy model describing both ADAFs and slim discs. We conclude with a presentation of the general-relativistic formalism describing accretion discs in the Kerr space-time.

  1. Newton-Cartan Gravity in Noninertial Reference Frames

    E-Print Network [OSTI]

    Leo Rodriguez; James St. Germaine-Fuller; Sujeev Wickramasekara


    We study properties of Newton-Cartan gravity under transformations into all noninertial, nonrelativistic reference frames. The set of these transformations has the structure of an infinite dimensional Lie group, called the Galilean line group, which contains as a subgroup the Galilei group. We show that the fictitious forces of noninertial reference frames are naturally encoded in the Cartan connection transformed under the Galilean line group. These noninertial forces, which are coordinate effects, do not contribute to the Ricci tensor which describes the curvature of Newtonian spacetime. We show that only the $00$-component of the Ricci tensor is non-zero and equal to ($4\\pi$ times) the matter density in any inertial or noninetial reference frame and that it leads to what may be called Newtonian ADM mass. While the Ricci field equation and Gauss law are both fulfilled by the same physical matter density in inertial and linearly accelerating reference frames, there appears a discrepancy between the two in rotating reference frames in that Gauss law holds for an effective mass density that differs from the physical matter density. This effective density has its origin in the simulated magnetic field that appears in rotating frames, highlighting a rather striking difference between linearly and rotationally accelerating reference frames. We further show that the dynamical equations that govern the simulated gravitational and magnetic fields have the same form as Maxwell's equations, a surprising conclusion given that these equations are well-known to obey special relativity (and $U(1)$-gauge symmetry), rather than Galilean symmetry.

  2. Anholonomic frames in constrained dynamics

    E-Print Network [OSTI]

    M. Crampin; T. Mestdag


    We demonstrate the usefulness of anholonomic frames in the contexts of nonholonomic and vakonomic systems. We take a consistently differential-geometric approach. As an application, we investigate the conditions under which the dynamics of the two systems will be consistent. A few illustrative examples confirm the results.

  3. Frame dragging with optical vortices

    E-Print Network [OSTI]

    Strohaber, James


    ). It is found that when a massive spinning neutral particle is placed along the optical axis, a phenomenon known as inertial frame dragging occurs. Our results are compared with those found previously for a ring laser and an order of magnitude estimate...

  4. Gravitational waves versus black holes

    E-Print Network [OSTI]

    Trevor W. Marshall


    It is argued that, in order for the gravitational field to be propagated as a wave, it is necessary for it to satisfy a further set of field equations, in addition to those of Einstein and Hilbert, and these equations mean there is a preferred coordinate frame, called the Global Inertial Frame, giving rise to a unique metric . The implication is that a true gravitational field is not compatible with Einstein's Principle of Equivalence, which is in contradiction with his other fundamental concept of locality. The additional field equations ensure that gravitational collapse does not go below the Schwarzschild radius, thereby excluding the possibility of singular solutions (black holes) of the Einstein-Hilbert equations. Such solutions would also violate Einstein's locality principle.

  5. Denoising using oversampled wavelet frames

    E-Print Network [OSTI]

    Barreto, Joel J


    in Ls(R) to a discrete signal P(J) where J C Z, T: L (IR))-) I (J) where the operator T is defined by (1. 5) T f = (ci}is~. T is called the frame operator. Note that T operating on f (i. e. Tf) generates a sequence. An operator S is said... (-, -) is continuous. A. Wavelet Frames Proceeding to the case of the discrete lattice, the discretization which generates the maximum interest is the one given below, a c? 1 f, kC Z. b ? o- k 2c (2. 2) Hence, vPI 'I(t) reduces to @t k(t):= 4(" '" ) (t) 2cg 2...

  6. Graphene and the Zermelo Optical Metric of the BTZ Black Hole

    E-Print Network [OSTI]

    M. Cvetic; G. W. Gibbons


    It is well known that the low energy electron excitations of the curved graphene sheet $\\Sigma$ are solutions of the massless Dirac equation on a 2+1 dimensional ultra-static metric on ${\\Bbb R} \\times \\Sigma$. An externally applied electric field on the graphene sheet induces a gauge potential which could be mimicked by considering a stationary optical metric of the Zermelo form, which is conformal to the BTZ black hole when the sheet has a constant negative curvature. The Randers form of the metric can model a magnetic field, which is related by a boost to an electric one in the Zermelo frame. We also show that there is fundamental geometric obstacle to obtaining a model that extends all the way to the black hole horizon.

  7. Geometry and constructions of finite frames

    E-Print Network [OSTI]

    Strawn, Nathaniel Kirk


    Finite frames are special collections of vectors utilized in Harmonic Analysis and Digital Signal Processing. In this thesis, geometric aspects and construction techniques are considered for the family of k-vector frames in Fn = Rn or Cn sharing a...

  8. Can Superconducting Cosmic Strings Piercing Seed Black Holes Generate Supermassive Black Holes in the Early Universe?

    E-Print Network [OSTI]

    Lake, Matthew J


    The discovery of a large number of supermassive black holes at redshifts $z> 6$, when the Universe was only nine hundred million years old, has raised the fundamental question of how such massive compact objects could form in a (cosmologically) short time interval. Each of the proposed standard scenarios for black hole formation, involving rapid accretion of seed black holes, or black hole mergers, faces severe theoretical difficulties in explaining the short time formation of supermassive objects. In the present Letter, we propose an alternative scenario for the formation of supermassive black holes in the early Universe in which energy transfer from superconducting cosmic strings, piercing small seed black holes, is the main physical process leading to rapid mass increase. The increase in mass of a primordial seed black hole pierced by two antipodal strings is estimated and it is shown that this increases linearly in time. Due to the high energy transfer rate from the cosmic strings, we find that supermassi...

  9. Coronal Holes

    E-Print Network [OSTI]

    Cranmer, Steven R


    Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations), and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are establish...

  10. Low energy 2+1 string gravity; black hole solutions

    E-Print Network [OSTI]

    A. A. Garcia Diaz; G. Gutierrez Cano


    In this report a detailed derivation of the dynamical equations for an n dimensional heterotic string theory of the Horowitz type is carried out in the string frame and in the Einstein frame too. In particular, the dynamical equations of the three dimensional string theory are explicitly given. The relation of the Horowitz Welch and Horne Horowitz string black hole solution is exhibited. The Chan Mann charged dilaton solution is derived and the subclass of string solutions field is explicitly identified. The stationary generalization, via SL(2;R) transformations, of the static (2+1) Horne Horowitz string black hole solution is given.

  11. Acceleration of particles by black holes: kinematic explanation

    E-Print Network [OSTI]

    O. B. Zaslavskii


    A new simple and general explanation of the effect of acceleration of particles by black holes to infinite energies in the centre of mass frame is suggested. It is based on kinematics of particles moving near the horizon. This effect arises when particles of two kinds collide near the horizon. For massive particles, the first kind represents a particle with the generic energy and angular momentum (I call them "usual"). Near the horizon, such a particle has a velocity almost equal to that of light in the frame that corotates with a black hole (the frame is static if a black hole is static). The second kind (called "critical") consists of particles with the velocity vvelocity approaches the speed of light c, the Lorentz factor grows unbound. This explanation applies both to generic rotating black holes and charged ones (even for radial motion of particles). If one of colliding particles is massless (photon), the critical particle is distinguished by the fact that its frequency is finite near the horizon. The existence (or absence) of the effect is determined depending on competition of two factors - gravitational blue shift for a photon propagating towards a black hole and the Doppler effect due to transformation from the locally nonrotating frame to a comoving one. Classification of all possible types of collisions is suggested depending on whether massive or massless particle is critical or usual.

  12. Spin Transport in non-inertial frame

    E-Print Network [OSTI]

    Debashree Chowdhury; B. Basu


    The influence of acceleration and rotation on spintronic applications is theoretically investigated. In our formulation, considering a Dirac particle in a non-inertial frame, different spin related aspects are studied. The spin current appearing due to the inertial spin-orbit coupling (SOC) is enhanced by the interband mixing of the conduction and valence band states. Importantly, one can achieve a large spin current through the $\\vec{k}. \\vec{p}$ method in this non-inertial frame. Furthermore, apart from the inertial SOC term due to acceleration, for a particular choice of the rotation frequency, a new kind of SOC term can be obtained from the spin rotation coupling (SRC). This new kind of SOC is of Dresselhaus type and controllable through the rotation frequency. In the field of spintronic applications, utilizing the inertial SOC and SRC induced SOC term, theoretical proposals for the inertial spin filter, inertial spin galvanic effect are demonstrated. Finally, one can tune the spin relaxation time in semiconductors by tuning the non-inertial parameters.

  13. Holographic Space-time and Newton's Law

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler


    We derive Newton's Law from the formalism of Holographic Space-Time (HST). More precisely, we show that for a large class of Hamiltonians of the type proposed previously for the HST description of a geodesic in Minkowski space, the eikonal for scattering of two massless particles at large impact parameter scales as expected with the impact parameter and the energies of the particles in the center of mass (CM) frame. We also discuss the criteria for black hole production in this collision, and find an estimate, purely within the HST framework, for the impact parameter at which it sets in, which coincides with the estimate based on general relativity.

  14. A multi-frame, megahertz CCD imager

    SciTech Connect (OSTI)

    Mendez, Jacob A [Los Alamos National Laboratory; Balzer, Stephen J [Los Alamos National Laboratory; Watson, Scott A [Los Alamos National Laboratory


    A high-efficiency, high-speed imager has been fabricated capable of framing rates of 2 MHz. This device utilizes a 512 x 512 pixel charge coupled device (CCD) with a 25cmZ active area, and incorporates an electronic shutter technology designed for back-illuminated CCD's, making this the largest and fastest back-illuminated CCD in the world. Characterizing an imager capable of this frame rate presents unique challenges. High speed LED drivers and intense radioactive sources are needed to perform basic measurements. We investigate properties normally associated with single-frame CCD's such as read noise, gain, full-well capacity, detective quantum efficiency (DQE), sensitivity, and linearity. In addition, we investigate several properties associated with the imager's multi-frame operation such as transient frame response and frame-to-frame isolation while contrasting our measurement techniques and results with more conventional devices.

  15. A multi-frame, megahertz CCd imager

    SciTech Connect (OSTI)

    Mendez, Jacob [Los Alamos National Laboratory; Balzer, Stephen [Los Alamos National Laboratory; Watson, Scott [Los Alamos National Laboratory; Reich, Robert [MIT-LL


    To record high-speed, explosively driven, events, a high efficiency, high speed, imager has been fabricated which is capable of framing rates of 2 MHz. This device utilizes a 512 x 512 pixel charge coupled device (CCD) with a 25cm{sup 2} active area, and incorporates an electronic shutter technology designed for back-illuminated CCD's, making this the largest and fastest back-illuminated CCD in the world. Characterizing an imager capable of this frame rate presents unique challenges. High speed LED drivers and intense radioactive sources are needed to perform the most basic measurements. We investigate properties normally associated with single-frame CCD's such as read noise, full-well capacity, sensitivity, signal to noise ratio, linearity and dynamic range. In addition, we investigate several properties associated with the imager's multi-frame operation such as transient frame response and frame-to-frame isolation while contrasting our measurement techniques and results with more conventional devices.

  16. Effects of Framing on the Thermal Performance of Wood and Steel-Framed Walls

    E-Print Network [OSTI]

    Kosny, J.; Yarbrough, D. W.; Childs, P.; Mohiuddin, S. A.


    , the consequences of installation imperfections in cavity insulation on thermal performance are analyzed. The results of the study demonstrated significant sensitivity in some configurations of residential walls to the framing factor and insulation installation... imperfections. Keywords R-value, Framing Factor, Cavity Insulation, Framing Effect Coefficient, Steel Frame walls, Wood-frame walls TERMINOLOGY OF THE WHOLE WALL R-VALUE PROCEDURE USED IN THIS PAPER The following list of thermal performance...

  17. RHIC | Black Holes?

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Black Holes at RHIC? Further discussion by Physicist Dmitri Kharzeev on why RHIC cannot produce a real gravitational black hole Black holes are among the most mysterious objects in...

  18. Black Hole Interior Mass Formula

    E-Print Network [OSTI]

    Parthapratim Pradhan


    We argue by explicit computations that, although the area product, horizon radii product, entropy product and \\emph {irreducible mass product} of the event horizon and Cauchy horizon are universal, the \\emph{surface gravity product}, \\emph{surface temperature product} and \\emph{Komar energy product} of the said horizons do not seem to be universal for Kerr-Newman (KN) black hole space-time. We show the black hole mass formula on the \\emph{Cauchy horizon} following the seminal work by Smarr\\cite{smarr} for the outer horizon. We also prescribed the \\emph{four} laws of black hole mechanics for the \\emph{inner horizon}. New definition of the extremal limit of a black hole is discussed.

  19. Absorption cross section of RN black hole

    E-Print Network [OSTI]

    Sini R.; V. C. Kuriakose


    The behavior of a charged scalar field in the RN black hole space time is studied using WKB approximation. In the present work it is assumed that matter waves can get reflected from the event horizon. Using this effect, the Hawking temperature and the absorption cross section for RN black hole placed in a charged scalar field are calculated. The absorption cross section $\\sigma _{abs}$ is found to be inversely proportional to square of the Hawking temperature of the black hole.

  20. Frame transforms, star products and quantum mechanics on phase space

    E-Print Network [OSTI]

    P. Aniello; V. I. Man'ko; G. Marmo


    Using the notions of frame transform and of square integrable projective representation of a locally compact group $G$, we introduce a class of isometries (tight frame transforms) from the space of Hilbert-Schmidt operators in the carrier Hilbert space of the representation into the space of square integrable functions on the direct product group $G\\times G$. These transforms have remarkable properties. In particular, their ranges are reproducing kernel Hilbert spaces endowed with a suitable 'star product' which mimics, at the level of functions, the original product of operators. A 'phase space formulation' of quantum mechanics relying on the frame transforms introduced in the present paper, and the link of these maps with both the Wigner transform and the wavelet transform are discussed.

  1. Acceleration of particles in Einstein-Maxwell-Dilaton black hole

    E-Print Network [OSTI]

    Pu-Jian Mao; Ran Li; Lin-Yu Jia; Ji-Rong Ren


    It has been recently pointed out that, under certain conditions, the energy of particles accelerated by black holes in the center-of-mass frame can become arbitrarily high. In this Letter, we study the collision of two particles around the four-dimensional Kaluza-Klein black hole in Einstein-Maxwell-Dilaton theory. We find that the center-of-mass energy for a pair of colliding particles is unlimited at the horizon of charged nonrotating and extremal rotating Kaluza-Klein black hole.

  2. Topological Black Holes in Quantum Gravity

    E-Print Network [OSTI]

    J. Kowalski-Glikman; D. Nowak-Szczepaniak


    We derive the black hole solutions with horizons of non-trivial topology and investigate their properties in the framework of an approach to quantum gravity being an extension of Bohm's formulation of quantum mechanics. The solutions we found tend asymptotically (for large $r$) to topological black holes. We also analyze the thermodynamics of these space-times.

  3. Integrated seat frame and back support

    DOE Patents [OSTI]

    Martin, Leo (Coconut Grove, FL)


    An integrated seating device comprises a seat frame having a front end and a rear end. The seat frame has a double wall defining an exterior wall and an interior wall. The rear end of the seat frame has a slot cut therethrough both the exterior wall and the interior wall. The front end of the seat frame has a slot cut through just the interior wall thereof. A back support comprising a generally L shape has a horizontal member, and a generally vertical member which is substantially perpendicular to the horizontal member. The horizontal member is sized to be threaded through the rear slot and is fitted into the front slot. Welded slat means secures the back support to the seat frame to result in an integrated seating device.

  4. State-of-the-Art Highly Insulating Window Frames - Research and Market Review

    SciTech Connect (OSTI)

    Gustavsen, Arild; Jelle, Bjorn Petter; Arasteh, Dariush; Kohler, Christian


    This document reports the findings of a market and research review related to state-of-the-art highly insulating window frames. The market review focuses on window frames that satisfy the Passivhaus requirements (window U-value less or equal to 0.8 W/m{sup 2}K ), while other examples are also given in order to show the variety of materials and solutions that may be used for constructing window frames with a low thermal transmittance (U-value). The market search shows that several combinations of materials are used in order to obtain window frames with a low U-value. The most common insulating material seems to be Polyurethane (PUR), which is used together with most of the common structural materials such as wood, aluminum, and PVC. The frame research review also shows examples of window frames developed in order to increase the energy efficiency of the frames and the glazings which the frames are to be used together with. The authors find that two main tracks are used in searching for better solutions. The first one is to minimize the heat losses through the frame itself. The result is that conductive materials are replaced by highly thermal insulating materials and air cavities. The other option is to reduce the window frame area to a minimum, which is done by focusing on the net energy gain by the entire window (frame, spacer and glazing). Literature shows that a window with a higher U-value may give a net energy gain to a building that is higher than a window with a smaller U-value. The net energy gain is calculated by subtracting the transmission losses through the window from the solar energy passing through the windows. The net energy gain depends on frame versus glazing area, solar factor, solar irradiance, calculation period and U-value. The frame research review also discusses heat transfer modeling issues related to window frames. Thermal performance increasing measures, surface modeling, and frame cavity modeling are among the topics discussed. The review shows that the current knowledge gives the basis for improving the calculation procedures in the calculation standards. At the same time it is room for improvement within some areas, e.g. to fully understand the natural convection effects inside irregular vertical frame cavities (jambs) and ventilated frame cavities.

  5. The Revival of White Holes as Small Bangs

    E-Print Network [OSTI]

    Alon Retter; Shlomo Heller


    Black holes are extremely dense and compact objects from which light cannot escape. There is an overall consensus that black holes exist and many astronomical objects are identified with black holes. White holes were understood as the exact time reversal of black holes, therefore they should continuously throw away material. It is accepted, however, that a persistent ejection of mass leads to gravitational pressure, the formation of a black hole and thus to the "death of while holes". So far, no astronomical source has been successfully tagged a white hole. The only known white hole is the Big Bang which was instantaneous rather than continuous or long-lasting. We thus suggest that the emergence of a white hole, which we name a 'Small Bang', is spontaneous - all the matter is ejected at a single pulse. Unlike black holes, white holes cannot be continuously observed rather their effect can only be detected around the event itself. Gamma ray bursts are the most energetic explosions in the universe. Long gamma-ray bursts were connected with supernova eruptions. There is a new group of gamma-ray bursts, which are relatively close to Earth, but surprisingly lack any supernova emission. We propose identifying these bursts with white holes. White holes seem like the best explanation of gamma-ray bursts that appear in voids. We also predict the detection of rare gigantic gamma-ray bursts with energies much higher than typically observed.

  6. Reference Frames, Gauge Transformations and Gravitomagnetism in the Post-Newtonian Theory of the Lunar Motion

    E-Print Network [OSTI]

    Yi Xie; Sergei Kopeikin


    We construct a set of reference frames for description of the orbital and rotational motion of the Moon. We use a scalar-tensor theory of gravity depending on two parameters of the parametrized post-Newtonian (PPN) formalism and utilize the concepts of the relativistic resolutions on reference frames adopted by the International Astronomical Union in 2000. We assume that the solar system is isolated and space-time is asymptotically flat. The primary reference frame has the origin at the solar-system barycenter (SSB) and spatial axes are going to infinity. The SSB frame is not rotating with respect to distant quasars. The secondary reference frame has the origin at the Earth-Moon barycenter (EMB). The EMB frame is local with its spatial axes spreading out to the orbits of Venus and Mars and not rotating dynamically in the sense that both the Coriolis and centripetal forces acting on a free-falling test particle, moving with respect to the EMB frame, are excluded. Two other local frames, the geocentric (GRF) and the selenocentric (SRF) frames, have the origin at the center of mass of the Earth and Moon respectively. They are both introduced in order to connect the coordinate description of the lunar motion, observer on the Earth, and a retro-reflector on the Moon to the observable quantities which are the proper time and the laser-ranging distance. We solve the gravity field equations and find the metric tensor and the scalar field in all frames. We also derive the post-Newtonian coordinate transformations between the frames and analyze the residual gauge freedom of the solutions of the field equations. We discuss the gravitomagnetic effects in the barycentric equations of the motion of the Moon and argue that they are beyond the current accuracy of lunar laser ranging (LLR) observations.

  7. Dynamics of Primordial Black Hole Formation

    E-Print Network [OSTI]

    J. C. Niemeyer; K. Jedamzik


    We present a numerical investigation of the gravitational collapse of horizon-size density fluctuations to primordial black holes (PBHs) during the radiation-dominated phase of the Early Universe. The collapse dynamics of three different families of initial perturbation shapes, imposed at the time of horizon crossing, is computed. The perturbation threshold for black hole formation, needed for estimations of the cosmological PBH mass function, is found to be $\\delta_{\\rm c} \\approx 0.7$ rather than the generally employed $\\delta_{\\rm c} \\approx 1/3$, if $\\delta$ is defined as $\\Delta M/\\mh$, the relative excess mass within the initial horizon volume. In order to study the accretion onto the newly formed black holes, we use a numerical scheme that allows us to follow the evolution for long times after formation of the event horizon. In general, small black holes (compared to the horizon mass at the onset of the collapse) give rise to a fluid bounce that effectively shuts off accretion onto the black hole, while large ones do not. In both cases, the growth of the black hole mass owing to accretion is insignificant. Furthermore, the scaling of black hole mass with distance from the formation threshold, known to occur in near-critical gravitational collapse, is demonstrated to apply to primordial black hole formation.

  8. Energy on black hole spacetimes

    E-Print Network [OSTI]

    Alejandro Corichi


    We consider the issue of defining energy for test particles on a background black hole spacetime. We revisit the different notions of energy as defined by different observers. The existence of a time-like isometry allows for the notion of a total conserved energy to be well defined, and subsequently the notion of a gravitational potential energy is also meaningful. We then consider the situation in which the test particle is adsorbed by the black hole, and analyze the energetics in detail. In particular, we show that the notion of horizon energy es defined by the isolated horizons formalism provides a satisfactory notion of energy compatible with the particle's conserved energy. As another example, we comment a recent proposal to define energy of the black hole as seen by an observer at rest. This account is intended to be pedagogical and is aimed at the level of and as a complement to the standard textbooks on the subject.

  9. Does Policy lead Mainstream Media? How Sources Framed the 2011 Egyptian Protests

    E-Print Network [OSTI]

    Grimmer, Kristen E


    Abstract This study uses a quantitative content analysis to determine the framing used by U.S. mainstream newspapers in media coverage of the 2011 Egyptian protests. The study examined 153 stories from The New York Times ...

  10. Gravitating discs around black holes

    E-Print Network [OSTI]

    V. Karas; J. -M. Hure; O. Semerak


    Fluid discs and tori around black holes are discussed within different approaches and with the emphasis on the role of disc gravity. First reviewed are the prospects of investigating the gravitational field of a black hole--disc system by analytical solutions of stationary, axially symmetric Einstein's equations. Then, more detailed considerations are focused to middle and outer parts of extended disc-like configurations where relativistic effects are small and the Newtonian description is adequate. Within general relativity, only a static case has been analysed in detail. Results are often very inspiring, however, simplifying assumptions must be imposed: ad hoc profiles of the disc density are commonly assumed and the effects of frame-dragging and completely lacking. Astrophysical discs (e.g. accretion discs in active galactic nuclei) typically extend far beyond the relativistic domain and are fairly diluted. However, self-gravity is still essential for their structure and evolution, as well as for their radiation emission and the impact on the environment around. For example, a nuclear star cluster in a galactic centre may bear various imprints of mutual star--disc interactions, which can be recognised in observational properties, such as the relation between the central mass and stellar velocity dispersion.

  11. Extracting Energy from Black Hole through Transition Region

    E-Print Network [OSTI]

    Li-Xin Li


    A new scenario for extracting energy from a Kerr black hole is proposed. With magnetic field lines connecting plasma particles inside the ergosphere with remote loads, the frame dragging twists the field lines so that energy and angular momentum are extracted from the plasma particles. If the magnetic field is strong enough, the energy extracted from the particles can be so large that the particles have negative energy as they fall into the black hole. So effectively the energy is extracted from the black hole. The particles inside the ergosphere can be continuously replenished with accretion from a disk surrounding the black hole, so a transition region with sufficient amount of plasma is formed between the black hole's horizon and the inner edge of the disk. Thus the energy can be continuously extracted from the black hole through the transition region. This may be the most efficient way for extracting energy from a Kerr black hole: in principle almost all of the rotational energy (up to $\\approx 29%$ of the total energy of the black hole) can be extracted.

  12. Ductile Fuses for Special Concentrically Braced Frames

    E-Print Network [OSTI]

    Bonetti, Santiago Antonio


    the braces to yield in a ductile manner while limiting the damage to the brace elements and the connections. Both fuse elements are intended to maintain frame strength under repeated cycles beyond yield both in tension and compression, providing balance...

  13. Light Steel Framing: Improving the Integral Design 

    E-Print Network [OSTI]

    Amundarain, Aitor; Torero, Jose L; Usmani, Asif; Al-Remal, Ahmad M


    Light Steel Framing has been extensively used in cold climate countries due to its good thermal and structural behaviour. Improved thermal behaviour results in positive environmental impact essential for sustainable ...

  14. Racial Framing and the Multiracial Movement

    E-Print Network [OSTI]

    Couch, Todd Christopher


    Members, Sarah N. Gatson Tommy J. Curry Head of Department, Mark Fossett May 2011 Major Subject: Sociology iii ABSTRACT Racial Framing and the Multiracial Movement. (May 2011) Todd Christopher Couch, B.A., Midwestern State...

  15. The Framing and Evaluation of Multiple Hypotheses

    E-Print Network [OSTI]

    Mock, Theodore J.; Wright, Arnold; Srivastava, Rajendra P.; Lu, Hai


    This study provides exploratory evidence on auditors’ framing and evaluation of hypotheses, identifies implications for improving audit decision-making and facilitates the interpretation of prior research. Prior studies ...

  16. Quantum corrections to the entropy of Einstein-Maxwell dilaton-axion black holes

    E-Print Network [OSTI]

    M. Akbar; K. Saifullah


    We study the corrections to the entropy of Einstein-Maxwell dilaton-axion black holes beyond semiclassical approximations. We consider the entropy of the black hole as a state variable and derive these corrections using the exactness criteria of the first law of thermodynamics. We note that from this general frame-work the entropy corrections for "simpler" black holes like Schwarzschild, Reissner-Nordstr\\"{o}m and anti-de Sitter-Schwarzschild black holes follow easily. This procedure gives us the modified area law as well.

  17. Quantum communication, reference frames and gauge theory

    E-Print Network [OSTI]

    S. J. van Enk


    We consider quantum communication in the case that the communicating parties not only do not share a reference frame but use imperfect quantum communication channels, in that each channel applies some fixed but unknown unitary rotation to each qubit. We discuss similarities and differences between reference frames within that quantum communication model and gauge fields in gauge theory. We generalize the concept of refbits and analyze various quantum communication protocols within the communication model.

  18. Optimal heat-reversible snap joints for frame-panel assembly in aluminum space frame automotive bodies

    E-Print Network [OSTI]

    Saitou, Kazuhiro "Kazu"

    Optimal heat-reversible snap joints for frame-panel assembly in aluminum space frame automotive, snap-fit joints, aluminum space frame 1 INTRODUCTION Aluminum space frame (AFS) automotive bodies to dramatically improve the recyclability of aluminum space frame (ASF) bodies by enabling clean separation

  19. Vortex hair on AdS black holes

    E-Print Network [OSTI]

    Gregory, Ruth; Kubiznak, David; Mann, Robert B; Wills, Danielle


    We analyse vortex hair for charged rotating asymptotically AdS black holes in the abelian Higgs model. We give analytical and numerical arguments to show how the vortex interacts with the horizon of the black hole, and how the solution extends to the boundary. The solution is very close to the corresponding asymptotically flat vortex, once one transforms to a frame that is non-rotating at the boundary. We show that there is a Meissner effect for extremal black holes, with the vortex flux being expelled from sufficiently small black holes. The phase transition is shown to be first order in the presence of rotation, but second order without rotation. We comment on applications to holography.

  20. Predictability in Quantum Gravity and Black Hole Evaporation

    E-Print Network [OSTI]

    J. W. Moffat


    A possible resolution of the information loss paradox for black holes is proposed in which a phase transition occurs when the temperature of an evaporating black hole equals a critical value, $T_c$, and Lorentz invariance and diffeomorphism invariance are spontaneously broken. This allows a generalization of Schr\\"odinger's equation for the quantum mechanical density matrix, such that a pure state can evolve into a mixed state, because in the symmetry broken phase the conservation of energy-momentum is spontaneously violated. TCP invariance is also spontaneously broken together with time reversal invariance, allowing the existence of white holes, which are black holes moving backwards in time. Domain walls would form which separate the black holes and white holes (anti-black holes) in the broken symmetry regime, and the system could evolve into equilibrium producing a balance of information loss and gain.

  1. High frame rate CCD camera with fast optical shutter

    SciTech Connect (OSTI)

    Yates, G.J.; McDonald, T.E. Jr. [Los Alamos National Lab., NM (United States); Turko, B.T. [Lawrence Berkeley National Lab., CA (United States)


    A high frame rate CCD camera coupled with a fast optical shutter has been designed for high repetition rate imaging applications. The design uses state-of-the-art microchannel plate image intensifier (MCPII) technology fostered/developed by Los Alamos National Laboratory to support nuclear, military, and medical research requiring high-speed imagery. Key design features include asynchronous resetting of the camera to acquire random transient images, patented real-time analog signal processing with 10-bit digitization at 40--75 MHz pixel rates, synchronized shutter exposures as short as 200pS, sustained continuous readout of 512 x 512 pixels per frame at 1--5Hz rates via parallel multiport (16-port CCD) data transfer. Salient characterization/performance test data for the prototype camera are presented, temporally and spatially resolved images obtained from range-gated LADAR field testing are included, an alternative system configuration using several cameras sequenced to deliver discrete numbers of consecutive frames at effective burst rates up to 5GHz (accomplished by time-phasing of consecutive MCPII shutter gates without overlap) is discussed. Potential applications including dynamic radiography and optical correlation will be presented.

  2. The effects of fastener hole defects

    E-Print Network [OSTI]

    Andrews, Scot D.


    ) August 1991 ABSTRACT The Effects of Fastener Hole Defects. (August 1991) Scot D. Andrews, B. S. , Texas A8rM University Chair of Advisory Committee: Dr. Orden O. Ochoa The influence of drilling-induced defects, such as delamination, on the fatigue... ambient and elevated temperature wet conditions. Specimens were tested in a bearing tension frame to static failure in order to measure the failure load and to calculate pin bearing stress. From static test results, a fatigue load was selected as 66...

  3. Neutrino interaction with background matter in a noninertial frame

    E-Print Network [OSTI]

    Dvornikov, Maxim


    We study Dirac neutrinos propagating in rotating background matter. First we derive the Dirac equation for a single massive neutrino in the noninertial frame, where matter is at rest. This equation is written in the effective curved space-time corresponding to the corotating frame. We find the exact solution of the Dirac equation. The neutrino energy levels for ultrarelativistic particles are obtained. Then we discuss several neutrino mass eigenstates, with a nonzero mixing between them, interacting with rotating background matter. We derive the effective Schr\\"{o}dinger equation governing neutrino flavor oscillations in rotating matter. The new resonance condition for neutrino oscillations is obtained. We also examine the correction to the resonance condition caused by the matter rotation.

  4. Some remarks on black hole thermodynamics

    E-Print Network [OSTI]

    R. Y. Chiao


    Two thermodynamic "paradoxes" of black hole physics are re-examined. The first is that there is a thermal instability involving two coupled blackbody cavities containing two black holes, and second is that a classical black hole can swallow up entropy in the form of ambient blackbody photons without increasing its mass. The resolution of the second paradox by Bekenstein and by Hawking is re-visited. The link between Hawking radiation and Wigner's superluminal tunneling time is discussed using two equivalent Feynman diagrams, and Feynman's re-interpretation principle.

  5. Degradation of a quantum reference frame

    E-Print Network [OSTI]

    Stephen D. Bartlett; Terry Rudolph; Robert W. Spekkens; Peter S. Turner


    We investigate the degradation of reference frames, treated as dynamical quantum systems, and quantify their longevity as a resource for performing tasks in quantum information processing. We adopt an operational measure of a reference frame's longevity, namely, the number of measurements that can be made against it with a certain error tolerance. We investigate two distinct types of reference frame: a reference direction, realized by a spin-j system, and a phase reference, realized by an oscillator mode with bounded energy. For both cases, we show that our measure of longevity increases quadratically with the size of the reference system and is therefore non-additive. For instance, the number of measurements that a directional reference frame consisting of N parallel spins can be put to use scales as N^2. Our results quantify the extent to which microscopic or mesoscopic reference frames may be used for repeated, high-precision measurements, without needing to be reset - a question that is important for some implementations of quantum computing. We illustrate our results using the proposed single-spin measurement scheme of magnetic resonance force microscopy.

  6. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

    E-Print Network [OSTI]

    Gustavsen Ph.D., Arild


    one aluminum frame and one PVC frame), found from numericalcellular polyvinylchloride (PVC) frame. Hot box results aremade of polyvinylchloride (PVC) (Frame E). The two thermally

  7. Thermodynamics of Schrödinger black holes with hyperscaling violation

    E-Print Network [OSTI]

    J. Sadeghi; B. Pourhassan; F. Pourasadollah


    In this work, we follow Kim and Yamada (JHEP1107 (2011) 120) and utilize AdS in light-cone frame to derive thermodynamic and transport properties of two kinds of Schr\\"{o}dinger black holes with hyperscaling violation. In that case, we show entropy and temperature are depend on $\\theta$. In $\\theta=0$ we see our results are agree with the work of Kim and Yamada. We also construct R-charged black hole with hyperscaling violation and obtain thermodynamics and transport properties.

  8. Rethinking Sustainability on Planet Earth: A Time for New Framings

    E-Print Network [OSTI]

    Dylan, Arielle


    2009). Carbon shift: How peak oil and the climate crisisEds. ), Carbon shift: How peak oil and the climate crisisof climate change, peak oil, and environmental degradation

  9. ARS 41-1072 Licensing Time Frames | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving You are now leaving You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1AMEE Jump to: navigation, search40 - Public Utilities

  10. Sen-Witten orthonormal three-frame and gravitational energy quasilocalization

    E-Print Network [OSTI]

    V. Pelykh


    Expression for the Witten-Nester 4-spinor 3-form of the Hamiltonian density of gravitational field in the asymptotically flat space-time in terms of the Sommers-Sen spinors, direct with a certain orthonormal three-frame connect, is obtained. A direct connection between the one and the ADM Hamiltonian density in the Sen-Witten frame is established on this basis.

  11. Quantum Black Holes Effects on the Shape of Extensive Air Showers

    E-Print Network [OSTI]

    Nicusor Arsene; Lauretiu Ioan Caramete; Peter B. Denton; Octavian Micu


    We investigate the possibility to find a characteristic TeV scale quantum black holes decay signature in the data recorded by cosmic rays experiments. TeV black holes can be produced via the collisions of ultra high energetic protons (E > $10^18$ eV) with nucleons the from atmosphere. We focus on the case when the black holes decay into two particles moving in the forward direction in the Earth reference frame (back-to-back in the center of mass reference frame) and induce two overlapping showers. When reconstructing both the energy and the shape of the resultant air shower, there is a significant difference between showers induced only via standard model interactions and showers produced via the back-to-back decay of black holes as intermediate states.

  12. Dynamics of black holes

    E-Print Network [OSTI]

    Sean A. Hayward


    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping horizon which manifests temporally as separate horizons.

  13. Topological Black Holes -- Outside Looking In

    E-Print Network [OSTI]

    R. B. Mann


    I describe the general mathematical construction and physical picture of topological black holes, which are black holes whose event horizons are surfaces of non-trivial topology. The construction is carried out in an arbitrary number of dimensions, and includes all known special cases which have appeared before in the literature. I describe the basic features of massive charged topological black holes in $(3+1)$ dimensions, from both an exterior and interior point of view. To investigate their interiors, it is necessary to understand the radiative falloff behaviour of a given massless field at late times in the background of a topological black hole. I describe the results of a numerical investigation of such behaviour for a conformally coupled scalar field. Significant differences emerge between spherical and higher genus topologies.

  14. A Quantum Material Model of Static Schwarzschild Black Holes

    E-Print Network [OSTI]

    S. -T. Sung


    A quantum-mechanical prescription of static Einstein field equation is proposed in order to construct the matter-metric eigen-states in the interior of a static Schwarzschild black hole where the signature of space-time is chosen as (--++). The spectrum of the quantum states is identified to be the integral multiples of the surface gravity. A statistical explanation of black hole entropy is given and a quantisation rule for the masses of Schwarzschild black holes is proposed.

  15. Texas Adapted Genetic Strategies for Beef Cattle X: Frame Score, Frame Size, and Weight

    E-Print Network [OSTI]

    Hammack, Stephen P.; Gill, Ronald J.


    Body size is an important genetic factor in beef cattle production. Size is most accurately estimated by considering several factors, such as weight, skeletal size and body condition. Frame Scores are a way of estimating skeletal size based on hip...

  16. Rotating Hairy Black Holes

    E-Print Network [OSTI]

    B. Kleihaus; J. Kunz


    We construct stationary black holes in SU(2) Einstein-Yang-Mills theory, which carry angular momentum and electric charge. Possessing non-trivial non-abelian magnetic fields outside their regular event horizon, they represent non-perturbative rotating hairy black holes.

  17. Disregarding the 'Hole Argument'

    E-Print Network [OSTI]

    Bryan W. Roberts


    Jim Weatherall has suggested that Einstein's hole argument, as presented by Earman and Norton (1987), is based on a misleading use of mathematics. I argue on the contrary that Weatherall demands an implausible restriction on how mathematics is used. The hole argument, on the other hand, is in no new danger at all.

  18. Einstein-Yang-Mills-Lorentz Black Holes

    E-Print Network [OSTI]

    Jose A. R. Cembranos; Jorge Gigante Valcarcel


    Different black hole solutions of the coupled Einstein-Yang-Mills equations are well known from long time. They have attracted much attention from mathematicians and physicists from their discovery. In this work, we analyze black holes associated with the gauge Lorentz group. In particular, we study solutions which identify the gauge connection with the spin connection. This ansatz allows to find exact solutions to the complete system of equations. By using this procedure, we show the equivalence between the Yang-Mills-Lorentz model in curved space-time and a particular set of extended gravitational theories.

  19. Scattering of Sound Waves by a Canonical Acoustic Hole

    E-Print Network [OSTI]

    Sam R. Dolan; Ednilton S. Oliveira; Luís C. B. Crispino


    This is a study of a monochromatic planar perturbation impinging upon a canonical acoustic hole. We show that acoustic hole scattering shares key features with black hole scattering. The interference of wavefronts passing in opposite senses around the hole creates regular oscillations in the scattered intensity. We examine this effect by applying a partial wave method to compute the differential scattering cross section for a range of incident wavelengths. We demonstrate the existence of a scattering peak in the backward direction, known as the glory. We show that the glory created by the canonical acoustic hole is approximately 170 times less intense than the glory created by the Schwarzschild black hole, for equivalent horizon-to-wavelength ratios. We hope that direct experimental observations of such effects may be possible in the near future.

  20. Black holes in extra dimensions can decay on the bulk

    E-Print Network [OSTI]

    A. K. Chaudhuri


    In the extra dimensional theories, with TeV scale Plank constant, black holes may be produced in the Large Hadron Collider experiments. We have argued that in the d-dimensional black hole, the intrinsically 4-dimensional brane fields do not see the same geometry at the horizon, as in a 4-dimensional space-time. Kaluza-Klein modes invades the brane and surroundings and the brane fields can be considered as a thermal system at the temperature of the black hole. From energy and entropy consideration, we show that whether or not a six-dimensional black hole will decay by emitting Kaluza-Klein modes or the standard model particles, will depend on the length scale of the extra dimensions as well as on the mass of the black hole. For higher dimensional black holes, Kaluza-Klein modes will dominate the decay.

  1. Multiplexing video streams using dual-frame video coding

    E-Print Network [OSTI]

    Tiwari, M; Groves, T; Cosman, P C


    novel idea for multiplexing video streams was to combine theLTR frames in dual-frame video coding with EqualSlope. T.Luthra, “Overview of the H.264/AVC video coding standard,”

  2. On Noncommutative Black Holes Thermodynamics

    E-Print Network [OSTI]

    Faizal, Mir; Ulhoa, S C


    In this paper, we will analyze noncommutative deformation of the Schwarzschild black holes and Kerr black holes. We will perform our analysis by relating the commutative and the noncommutative metrics using an Moyal product. We will also analyze the thermodynamics of these noncommutative black hole solutions. We will explicitly derive expression for the corrected entropy and temperature of these black hole solutions.

  3. Chromidio: an interface for color tracking with key frames in Max and Nato

    E-Print Network [OSTI]

    Tucker, Amy Rebecca


    11 QuickTime Movie Input 11 Interactive Color Picking 12 Key Frames 12 Useful Output 14 File Management 16 I 6 IV I M P L E M E N T A T I O N A N D RESULTS 17 Chromidio User Interface 17 QuickTime Movie Display and Playback 22 vi i... CHAPTER Page Interactive Color Picking 26 Key Frame Management 27 Data Analysis and Output 32 Project File Management 36 39 User Interface 39 Mathematical Functions and F ilters 41 MIDI Implementations 44 Output : 46 Results Using C...

  4. Variations in diagnostic and prognostic framing in the EZLN movement

    E-Print Network [OSTI]

    Pinnick, Aaron Corbett


    -liberal Government.......????????????????.......55 4.5 Prognostic Frame Overview????????????????........60 4.6 General Democracy?????????????????????.62 4.7 Autonomous Democracy???????????????????.66 4.8 Revolutionary Frame????????????????????...67 4... government, and neo-liberal government) and three prognostic frames (democracy in general, local autonomous democracy, and large scale revolution). While more will be said about how each of these frames will be defined and coded later, the research argues...

  5. On the construction of Fermi-Walker transported frames

    E-Print Network [OSTI]

    J. W. Maluf; F. F. Faria


    We consider tetrad fields as reference frames adapted to observers that move along arbitrary timelike trajectories in spacetime. By means of a local Lorentz transformation we can transform these frames into Fermi-Walker transported frames, which define a standard of non-rotation for accelerated observers. Here we present a simple prescription for the construction of Fermi-Walker transported frames out of an arbitrary set of tetrad fields.

  6. Turbodrilling in the hot-hole environment

    SciTech Connect (OSTI)

    Herbert, P.


    Historically, geothermal and other types of hot-hole drilling have presented what seemed to be insurmountable barriers to efficient and extended use of downhole drilling motors, particularly those containing elastomeric bearing or motor components. Typical temperatures of 350 to 700/sup 0/F (177 to 371/sup 0/C) damage the elastomers and create other operating problems, reducing the life of the motors and their ability to drill efficiently. Recent innovations in turbodrill design have opened heretofore unrealized potentials and have allowed, for the first time, extended downhole drilling time in hot-hole conditions. The unique feature of this turbodrill is the lack of any elastomers or other temperature-sensitive materials. Its capabilities are matched closely to the requirements of drilling in elevated-temperature environments. The bearing assembly can withstand conditions encountered in typical geothermal formations and provides the performance necessary to stay in the hole. The result is increased rate of penetration (ROP) and more economical drilling.

  7. Wavelet Frame Based Surface Reconstruction from Unorganized Points

    E-Print Network [OSTI]

    Zakharov, Vladimir

    Wavelet Frame Based Surface Reconstruction from Unorganized Points Bin Donga, , Zuowei Shenb, 119076. Abstract Applications of wavelet frames to image restoration problems (e.g. image deblurring smooth functions like images (see e.g. [13, 14, 8]). However, wavelet frames have not yet been used

  8. Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad

    E-Print Network [OSTI]

    Media Framing and Public Attitudes Toward Biofuels Ashlie Delshad Department of Political Science between media framing and public opinion on the issue of biofuels--transportation fuels made from plants, animal products, or organic waste. First, the paper investigates how media framing of biofuels has

  9. Holes in Spectral Lines

    E-Print Network [OSTI]

    Fontana, Peter R.; Srivastava, Rajendra P.


    The decay of an atom in the presence of a static perturbation is investigated. The perturbation couples a decaying state with a nondecaying state. A "hole" appears in the emission line at a frequency equal to the frequency difference between...

  10. Do Black Holes Exist?

    E-Print Network [OSTI]

    J. W. Moffat


    The problem of information loss in black hole formation and the associated violations of basic laws of physics, such as conservation of energy, causality and unitarity, are avoided in the nonsymmetric gravitational theory, if the NGT charge of a black hole and its mass satisfy an inequality that does not violate any known experimental data and allows the existence of white dwarfs and neutron stars.

  11. Helical superconducting black holes

    E-Print Network [OSTI]

    Aristomenis Donos; Jerome P. Gauntlett


    We construct novel static, asymptotically $AdS_5$ black hole solutions with Bianchi VII$_0$ symmetry that are holographically dual to superconducting phases in four spacetime dimensions with a helical p-wave order. We calculate the precise temperature dependence of the pitch of the helical order. At zero temperature the black holes have vanishing entropy and approach domain wall solutions that reveal homogenous, non-isotropic dual ground states with emergent scaling symmetry.

  12. Classical Radiation Formula in the Rindler Frame

    E-Print Network [OSTI]

    Toru Hirayama


    In a preceding paper [T. Hirayama, Prog. Theor. Phys. 106 (2001), 71], the power of the classical radiation emitted by a moving charge was evaluated in the Rindler frame. In this paper, we give a simpler derivation of this radiation formula, including an estimation of the directional dependence of the radiation. We find that the splitting of the energy-momentum tensor into a bound part I' and an emitted part II' is consistent with the three conditions introduced in the preceding paper, also for each direction within the future light cone.

  13. Propagating torsion in the Einstein frame

    SciTech Connect (OSTI)

    Poplawski, Nikodem J. [Department of Physics, Indiana University, 727 East Third Street, Bloomington, Indiana 47405 (United States)


    The Einstein-Cartan-Saa theory of torsion modifies the spacetime volume element so that it is compatible with the connection. The condition of connection compatibility gives constraints on torsion, which are also necessary for the consistence of torsion, minimal coupling, and electromagnetic gauge invariance. To solve the problem of positivity of energy associated with the torsionic scalar, we reformulate this theory in the Einstein conformal frame. In the presence of the electromagnetic field, we obtain the Hojman-Rosenbaum-Ryan-Shepley theory of propagating torsion with a different factor in the torsionic kinetic term.

  14. Schwarzschild black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh


    In this paper we present an exact solution of Einstein's field equations describing the Schwarzschild black hole in dark energy background. It is also regarded as an embedded solution that the Schwarzschild black hole is embedded into the dark energy space producing Schwarzschild-dark energy black hole. It is found that the space-time geometry of Schwarzschild-dark energy solution is non-vacuum Petrov type $D$ in the classification of space-times. We study the energy conditions (like weak, strong and dominant conditions) for the energy-momentum tensor of the Schwarzschild-dark energy solution. We also find that the energy-momentum tensor of the Schwarzschild-dark energy solution violates the strong energy condition due to the negative pressure leading to a repulsive gravitational force of the matter field in the space-time. It is shown that the time-like vector field for an observer in the Schwarzschild-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity and the area of the horizons for the Schwarzschild-dark energy black hole.

  15. Thermal Gravitational Waves from Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun


    Thermal gravitational waves can be generated in various sources such as, in the cores of stars, white dwarfs and neutron stars due to the fermion collisions in the dense degenerate Fermi gas. Such high frequency thermal gravitational waves can also be produced during the collisions in a gamma ray burst or during the final stages of the evaporation of primordial black holes. Here we estimate the thermal gravitational waves from primordial black holes and estimate the integrated energy of the gravitational wave emission over the entire volume of the universe and over Hubble time. We also estimate the gravitational wave flux from gamma ray bursts and jets.

  16. Adaptive Display Algorithm for Interactive Frame Rates During Visualization of Complex Virtual Environments

    E-Print Network [OSTI]

    Singh, Jaswinder Pal

    -- viewing algorithms; I.3.5 Computational Geometry and Object Modeling -- geometric algorithms, object rates. Furthermore, the complexity of the portion of the model visible to the observer can be highly on any single frame time. Using the UC Berkeley Building Walkthrough System [5] and a model of Soda Hall

  17. Saha Equation in an Uniformly Accelerated Reference Frame and Some of Its Physical Implications

    E-Print Network [OSTI]

    Sanchari De; Somenath Chakrabarty


    The Saha equations for the photo-ionization of hydrogen atoms and the electron positron pair production at high temperature are obtained in a reference frame undergoing a uniform accelerated motion in an otherwise flat Minkowski space-time geometry. Some of the physical implications of our findings are discussed.

  18. Investigating Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher


    The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.

  19. Weitzenböck's Torsion, Fermi Coordinates and Adapted Frames

    E-Print Network [OSTI]

    Donato Bini; Bahram Mashhoon


    We study Weitzenb\\"ock's torsion and discuss its properties. Specifically, we calculate the measured components of Weitzenb\\"ock's torsion tensor for a frame field adapted to static observers in a Fermi normal coordinate system that we establish along the world line of an arbitrary accelerated observer in general relativity. A similar calculation is carried out in the standard Schwarzschild-like coordinates for static observers in the exterior Kerr spacetime; we then compare our results with the corresponding curvature components. Our work supports the contention that in the extended general relativistic framework involving both the Levi-Civita and Weitzenb\\"ock connections, curvature and torsion provide complementary representations of the gravitational field.

  20. Reference-frame-independent quantum key distribution

    SciTech Connect (OSTI)

    Laing, Anthony; Rarity, John G.; O'Brien, Jeremy L. [Centre for Quantum Photonics, H. H. Wills Physics Laboratory and Department of Electrical and Electronic Engineering, University of Bristol, BS8 1UB (United Kingdom); Scarani, Valerio [Centre for Quantum Technologies and Department of Physics, National University of Singapore (Singapore)


    We describe a quantum key distribution protocol based on pairs of entangled qubits that generates a secure key between two partners in an environment of unknown and slowly varying reference frame. A direction of particle delivery is required, but the phases between the computational basis states need not be known or fixed. The protocol can simplify the operation of existing setups and has immediate applications to emerging scenarios such as earth-to-satellite links and the use of integrated photonic waveguides. We compute the asymptotic secret key rate for a two-qubit source, which coincides with the rate of the six-state protocol for white noise. We give the generalization of the protocol to higher-dimensional systems and detail a scheme for physical implementation in the three-dimensional qutrit case.

  1. Thermodynamical instability of black holes

    E-Print Network [OSTI]

    V. V. Kiselev


    In contrast to Hawking radiation of black hole with a given spacetime structure, we consider a competitive transition due to a heat transfer from a hotter inner horizon to a colder outer horizon of Kerr black hole, that results in a stable thermodynamical state of extremal black hole. In this process, by supposing an emission of gravitational quanta, we calculate the mass of extremal black hole in the final state of transition.

  2. Towards noncommutative quantum black holes

    SciTech Connect (OSTI)

    Lopez-Dominguez, J. C.; Obregon, O.; Sabido, M.; Ramirez, C. [Instituto de Fisica de la Universidad de Guanajuato, P.O. Box E-143, 37150 Leon Gto. (Mexico); Facultad de Ciencias Fisico Matematicas, Universidad Autonoma de Puebla, P.O. Box 1364, 72000 Puebla (Mexico)


    In this paper we study noncommutative black holes. We use a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate the Hawking's temperature and entropy for the noncommutative Schwarzschild black hole.

  3. Nonlinear seismic response analysis of steel-concrete composite frames

    E-Print Network [OSTI]

    Barbato, Michele


    formulation of nonlinear steel- concrete composite beam ele-Behaviour of Composite Steel and Concrete Struc- turalE. (2001). “Analysis of steel-concrete composite frames with

  4. Laser bottom hole assembly

    DOE Patents [OSTI]

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O


    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  5. Quantum black hole inflation

    E-Print Network [OSTI]

    M. B. Altaie


    In this paper we follow a new approach for particle creation by a localized strong gravitational field. The approach is based on a definition of the physical vacuum drawn from Heisenberg uncertainty principle. Using the fact that the gravitational field red-shifts the frequency modes of the vacuum, a condition on the minimum stregth of the gravitational field required to achieve real particle creation is derived. Application of this requirement on a Schwartzchid black hole resulted in deducing an upper limit on the region, outside the event horizon, where real particles can be created. Using this regional upper limit, and considering particle creation by black holes as a consequence of the Casimir effect, with the assumption that the created quanta are to be added to the initial energy, we deduce a natural power law for the development of the event horizon, and consequently a logarithmic law for the area spectrum of an inflating black hole. Application of the results on a cosmological model shows that if we start with a Planck-dimensional black hole, then through the process of particle creation we end up with a universe having the presently estimated critical density. Such a universe will be in a state of eternal inflation.

  6. Black Holes at Accelerators

    E-Print Network [OSTI]

    Bryan Webber


    In theories with large extra dimensions and TeV-scale gravity, black holes are copiously produced in particle collisions at energies well above the Planck scale. I briefly review some recent work on the phenomenology of this process, with emphasis on theoretical uncertainties and possible strategies for measuring the number of extra dimensions.

  7. Energy decomposition within Einstein-Born-Infeld black holes

    E-Print Network [OSTI]

    Jonas P. Pereira; Jorge A. Rueda


    We analyze the consequences of the recently found generalization of the Christodoulou-Ruffini black hole mass decomposition for Einstein-Born-Infeld black holes [characterized by the parameters $(Q,M,b)$, where $M = M(M_{irr},Q,b)$, $b$ scale field, $Q$ charge, $M_{irr}$ "irreducible mass", physically meaning the energy of a black hole when its charge is null] and their interactions. We show in this context that their description is largely simplified and can basically be split into two families depending upon the parameter $b|Q|$. If $b|Q|\\leq 1/2$, then black holes could have even zero irreducible masses and they always exhibit single, non degenerated, horizons. If $b|Q|>1/2$, then an associated black hole must have a minimum irreducible mass (related to its minimum energy) and has two horizons up to a transitional irreducible mass. For larger irreducible masses, single horizon structures raise again. By assuming that black holes emit thermal uncharged scalar particles, we further show in light of the black hole mass decomposition that one satisfying $b|Q|>1/2$ takes an infinite amount of time to reach the zero temperature, settling down exactly at its minimum energy. Finally, we argue that depending on the fundamental parameter $b$, the radiation (electromagnetic and gravitational) coming from Einstein-Born-Infeld black holes could differ significantly from Einstein-Maxwell ones. Hence, it could be used to assess such a parameter.

  8. Gravitational-wave modes from precessing black-hole binaries

    E-Print Network [OSTI]

    Michael Boyle; Lawrence E. Kidder; Serguei Ossokine; Harald P. Pfeiffer


    Gravitational waves from precessing black-hole binaries exhibit features that are absent in nonprecessing systems. The most prominent of these is a parity-violating asymmetry that beams energy and linear momentum preferentially along or opposite to the orbital angular momentum, leading to recoil of the binary. The asymmetry will appear as amplitude and phase modulations at the orbital frequency. For strongly precessing systems, it accounts for at least 3% amplitude modulation for binaries in the sensitivity band of ground-based gravitational-wave detectors, and can exceed 50% for massive systems. Such asymmetric features are also clearly visible when the waves are decomposed into modes of spin-weighted spherical harmonics, and are inherent in the waves themselves---rather than resulting from residual eccentricity in numerical simulations, or from mode-mixing due to precession. In particular, there is generically no instantaneous frame for which the mode decomposition will have any symmetry. We introduce a method to simplify the expressions for waveforms given in analytical relativity, which can be used to combine existing high-order waveforms for nonprecessing systems with expressions for the precessing contributions, leading to improved accuracy and a unified treatment of precessing and nonprecessing binaries. Using this method, it is possible to clarify the nature and the origins of the asymmetries and show the effects of asymmetry on recoils more clearly. We present post-Newtonian (PN) expressions for the waveform modes that include these terms, complete to the relative 2PN level in spin (proportional to $v^4/c^4$ times a certain combination of the spins). Comparing the results of those expressions to numerical results, we find good qualitative agreement. We also demonstrate how these expressions can be used to efficiently calculate waveforms for gravitational-wave astronomy.

  9. Testing the general relativistic ''no-hair'' theorems using the galactic center black hole SgrA*

    E-Print Network [OSTI]

    Clifford M. Will


    If a class of stars orbits the central black hole in our galaxy in short period (~ 0.1 year), high eccentricity (~ 0.9) orbits, they will experience precessions of their orbital planes induced by both relativistic frame-dragging and the quadrupolar gravity of the hole, at levels that could be as large as 10 microarcseconds per year, if the black hole is rotating faster than 1/2 of its maximum rotation rate. Astrometric observations of the orbits of at least two such stars can in principle lead to a determination of the angular momentum vector J of the black hole and its quadrupole moment Q_2. This could lead to a test of the general relativistic no-hair theorems, which demand that Q_2 = - J^2/M. Future high-precision adaptive infrared optics instruments make make such a fundamental test of the black-hole paradigm possible.

  10. CE 4990 -Construction Scheduling Week 1: Steel Frame Project

    E-Print Network [OSTI]

    Mukherjee, Amlan

    CE 4990 - Construction Scheduling Week 1: Steel Frame Project Fall 2011 January 13, 2012 Introduction You are a construction manager for a project to build a steel frame for an office building1 of 964 pre-fabricated structural steel members will be used in the construction. The standard bay size

  11. What is the reference frame of an accelerated observer?

    E-Print Network [OSTI]

    K. -P. Marzlin


    The general construction of extended refrence frames for noninertial observers in flat space is studied. It is shown that, if the observer moves inertially before and after an arbitrary acceleration and rotation, the region where reference frames can coincide with an inertial system is bounded for final velocities exceeding 0.6 c.

  12. Predicting Performance of PESQ in Case of Single Frame Losses

    E-Print Network [OSTI]

    Wichmann, Felix

    Predicting Performance of PESQ in Case of Single Frame Losses Christian Hoene, Enhtuya Dulamsuren-Lalla Technical University of Berlin, Germany Fax: +49 30 31423819 Email: Abstract ITU's objective can measure the impact of single frame losses ­ a source of impairment for which PESQ has not been


    SciTech Connect (OSTI)

    Takahashi, Masaaki [Department of Physics and Astronomy, Aichi University of Education, Kariya, Aichi 448-8542 (Japan); Takahashi, Rohta, E-mail: [Cosmic Radiation Laboratory, Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)


    We present a model for high-energy emission sources generated by a standing magnetohydrodynamical (MHD) shock in a black hole magnetosphere. The black hole magnetosphere would be constructed around a black hole with an accretion disk, where a global magnetic field could be originated by currents in the accretion disk and its corona. Such a black hole magnetosphere may be considered as a model for the central engine of active galactic nuclei, some compact X-ray sources, and gamma-ray bursts. The energy sources of the emission from the magnetosphere are the gravitational and electromagnetic energies of magnetized accreting matters and the rotational energy of a rotating black hole. When the MHD shock generates in MHD accretion flows onto the black hole, the plasma's kinetic energy and the black hole's rotational energy can convert to radiative energy. In this Letter, we demonstrate the huge energy output at the shock front by showing negative energy postshock accreting MHD flows for a rapidly rotating black hole. This means that the extracted energy from the black hole can convert to the radiative energy at the MHD shock front. When an axisymmetric shock front is formed, we expect a ring-shaped region with very hot plasma near the black hole; this would look like an 'aurora'. The high-energy radiation generated from there would carry to us the information for the curved spacetime due to the strong gravity.

  14. Holes in the ghost condensate

    SciTech Connect (OSTI)

    Krotov, D. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation); Moscow State University, Department of Physics, Vorobjevy Gory, Moscow, 119899 (Russian Federation); Institute of Theoretical and Experimental Physics, B. Cheremushkinskaya, 25, Moscow, 117259 (Russian Federation); Rebbi, C. [Department of Physics, Boston University, 590 Commonwealth Avenue, Boston Massachusetts 02215 (United States); Rubakov, V. [Institute for Nuclear Research of the Russian Academy of Sciences, 60th October Anniversary prospect 7a, Moscow 117312 (Russian Federation); Zakharov, V. [Max-Planck Institut fuer Physik, Foeringer Ring 6, 80805, Munichn (Germany)


    In a recently proposed model of 'ghost condensation', spatially homogeneous states may mix, via tunneling, with inhomogeneous states which are somewhat similar to bubbles in the theory of false vacuum decay, the corresponding bubble nucleation rate being exponentially sensitive to the ultraviolet completion of the model. The conservation of energy and charge requires that the energy density is negative and the field is strongly unstable in a part of the nucleated bubble. Unlike in the theory of false vacuum decay, this region does not expand during subsequent real-time evolution. In the outer part, positive energy outgoing waves develop, which eventually form shocks. Behind the outgoing waves and away from the bubble center, the background settles down to its original value. The outcome of the entire process is thus a microscopic region of negative energy and strong field - 'hole in the ghost condensate' - plus a collection of outgoing waves (particles of the ghost condensate field) carrying away finite energy.

  15. Shape of black holes

    E-Print Network [OSTI]

    Clement, María E Gabach


    It is well known that celestial bodies tend to be spherical due to gravity and that rotation produces deviations from this sphericity. We discuss what is known and expected about the shape of black holes' horizons from their formation to their final, stationary state. We present some recent results showing that black hole rotation indeed manifests in the widening of their central regions, limits their global shapes and enforces their whole geometry to be close to the extreme Kerr horizon geometry at almost maximal rotation speed. The results depend only on the horizon area and angular momentum. In particular they are entirely independent of the surrounding geometry of the spacetime and of the presence of matter satisfying the strong energy condition. We also discuss the the relation of this result with the Hoop conjecture.

  16. Black hole evolution: I. Supernova-regulated black hole growth

    E-Print Network [OSTI]

    Dubois, Yohan; Silk, Joseph; Devriendt, Julien; Slyz, Adrianne; Teyssier, Romain


    The growth of a supermassive black hole (BH) is determined by how much gas the host galaxy is able to feed it, which in turn is controlled by the cosmic environment, through galaxy mergers and accretion of cosmic flows that time how galaxies obtain their gas, but also by internal processes in the galaxy, such as star formation and feedback from stars and the BH itself. In this paper, we study the growth of a 10^12 Msun halo at z=2, which is the progenitor of an archetypical group of galaxies at z=0, and of its central BH by means of a high-resolution zoomed cosmological simulation, the Seth simulation. We study the evolution of the BH driven by the accretion of cold gas in the galaxy, and explore the efficiency of the feedback from supernovae (SNe). For a relatively inefficient energy input from SNe, the BH grows at the Eddington rate from early times, and reaches self-regulation once it is massive enough. We find that at early cosmic times z>3.5, efficient feedback from SNe forbids the formation of a settled...

  17. Black holes in massive gravity

    E-Print Network [OSTI]

    Babichev, Eugeny


    We review the black hole solutions of the ghost-free massive gravity theory and its bimetric extension and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact black hole solutions, analogous to those of General Relativity. In addition to these solutions, hairy black holes -- solutions with no correspondent in General Relativity -- have been found numerically, whose existence is a natural consequence of the absence of the Birkhoff's theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these black holes richer and more complex than those of General Relativity. In particular, the bi-Schwarzschild black hole exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical black holes are described by these solutions, the superradiant instability o...

  18. Black Hole's 1/N Hair

    E-Print Network [OSTI]

    Gia Dvali; Cesar Gomez


    According to the standard view classically black holes carry no hair, whereas quantum hair is at best exponentially weak. We show that suppression of hair is an artifact of the semi-classical treatment and that in the quantum picture hair appears as an inverse mass-square effect. Such hair is predicted in the microscopic quantum description in which a black hole represents a self-sustained leaky Bose-condensate of N soft gravitons. In this picture the Hawking radiation is the quantum depletion of the condensate. Within this picture we show that quantum black hole physics is fully compatible with continuous global symmetries and that global hair appears with the strength B/N, where B is the global charge swallowed by the black hole. For large charge this hair has dramatic effect on black hole dynamics. Our findings can have interesting astrophysical consequences, such as existence of black holes with large detectable baryonic and leptonic numbers.

  19. Simulating merging binary black holes with nearly extremal spins

    SciTech Connect (OSTI)

    Lovelace, Geoffrey [Center for Radiophysics and Space Research, Cornell University, Ithaca, New York, 14853 (United States); Scheel, Mark A.; Szilagyi, Bela [Theoretical Astrophysics 350-17, California Institute of Technology, Pasadena, California 91125 (United States)


    Astrophysically realistic black holes may have spins that are nearly extremal (i.e., close to 1 in dimensionless units). Numerical simulations of binary black holes are important tools both for calibrating analytical templates for gravitational-wave detection and for exploring the nonlinear dynamics of curved spacetime. However, all previous simulations of binary-black-hole inspiral, merger, and ringdown have been limited by an apparently insurmountable barrier: the merging holes' spins could not exceed 0.93, which is still a long way from the maximum possible value in terms of the physical effects of the spin. In this paper, we surpass this limit for the first time, opening the way to explore numerically the behavior of merging, nearly extremal black holes. Specifically, using an improved initial-data method suitable for binary black holes with nearly extremal spins, we simulate the inspiral (through 12.5 orbits), merger and ringdown of two equal-mass black holes with equal spins of magnitude 0.95 antialigned with the orbital angular momentum.

  20. Means to flexibly attach lens frames to temple members

    DOE Patents [OSTI]

    Smith, Harry D. (Richland, WA)


    The invention is a band hinge for flexibly connecting the temple member to the lens frame thereby preventing damage from inadvertent pressure or cyclic wear. A distinguishing feature of the invention is the use of a band hinge that holds together the temple member and the lens frame without the use of a pin or screw hinging mechanism. The invention allows for a high degree of freedom of movement for the temple member with respect to the lens frame which will prevent most forms of damages to the glasses from these types of events.

  1. A two-frame sampling survey: the Edwards Plateau study

    E-Print Network [OSTI]

    Burcham, George William


    A TI!O-I RARE Si' IPLIIIS SUR'JEY: I I'E EDI I'RDS PLATEAU STUDY Thesis CEORBE k&II I 1AIi BURCIIAk" Suh, sitted !. o the qraduete Co11eqe of Texas, ""I L'! Iversity in Prn tia1 fu1fi11ment o+ Lhe renui& e sent for the deqree of , 'IAS... frame is a 'list ;"rame, " a frame containing a list of ~ames of individuals who are members of the larget population. In the list frame the mail- ing of questionnaires v!ith a follow"up of non-response is low in cos , but may produce biased...

  2. Price-Responsive Load (PRL) Program - Framing Paper No.1

    SciTech Connect (OSTI)

    Goldman, Charles A.


    By definition, effective and efficient competitive markets need a supply side and a demand side. One criticism of electric restructuring efforts in many states is that most of the attention has been focused on the supply side, in a market focused on the short term. In general, the demand side of the market has been under-addressed. The objective of the New England Demand Response Initiative (NEDRI) is to develop a comprehensive, coordinated set of demand response programs for the New England regional power markets. NEDRI aims to maximize the capability of demand response to compete in the wholesale market and to improve the economic efficiency and environmental profile of the electric sector. To those ends, NEDRI is focusing its efforts in four interrelated areas: (1) ISO-level reliability programs, (2) Market-based price-responsive load programs, (3) Demand response at retail through pricing, rate design, and advanced metering, and (4) End-use energy efficiency resources as demand response. The fourth area, energy efficiency, is the subject of this framing paper. Energy efficiency reduces the energy used by specific end-use devices and systems, typically without affecting the level of service and without loss of amenity. Energy savings and peak load reductions are achieved by substituting technically more advanced equipment, processes, or operational strategies to produce the same or an improved level of end-use service with less electricity. In contrast, load management programs lower peak demand during specific, limited time periods by either (1) influencing the timing of energy use by shifting load to another time period, or (2) reducing the level of energy use by curtailing or interrupting the load, typically with some loss of service or amenity.

  3. Observational Evidence for Black Holes

    E-Print Network [OSTI]

    Ramesh Narayan; Jeffrey E. McClintock


    Astronomers have discovered two populations of black holes: (i) stellar-mass black holes with masses in the range 5 to 30 solar masses, millions of which are present in each galaxy in the universe, and (ii) supermassive black holes with masses in the range 10^6 to 10^{10} solar masses, one each in the nucleus of every galaxy. There is strong circumstantial evidence that all these objects are true black holes with event horizons. The measured masses of supermassive black hole are strongly correlated with properties of their host galaxies, suggesting that these black holes, although extremely small in size, have a strong influence on the formation and evolution of entire galaxies. Spin parameters have recently been measured for a handful of black holes. Based on the data, there is an indication that the kinetic power of at least one class of relativistic jet ejected from accreting black holes may be correlated with black hole spin. If verified, it would suggest that these jets are powered by a generalized Penrose process mediated by magnetic fields.

  4. Gravitational radiation, energy and reaction on quasi-spherical black holes

    E-Print Network [OSTI]

    Sean A. Hayward


    Gravitational radiation is locally defined where the wavefronts are roughly spherical. A local energy tensor is defined for the gravitational radiation. Including this energy tensor as a source in the truncated Einstein equations describes gravitational radiation reaction, such as back-reaction on a roughly spherical black hole. The energy-momentum in a canonical frame is covariantly conserved. The strain to be measured by a distant detector is simply defined.

  5. Horizon news function and quasi-local energy-momentum flux near black hole

    E-Print Network [OSTI]

    Yu-Huei Wu


    From the 'quasi-local' definition of horizons, e.g. isolated horizon and dynamical horizon, the consequence quasi-local energy-momentum near horizons can be observed by using the idea of frame alignment. In particular, we find the horizon news function from the asymptotic expansion near horizons and use this to describe the gravitational flux and change of mass of a black hole.

  6. Dynamics of stellar black holes in young star clusters with different metallicities - II. Black hole-black hole binaries

    E-Print Network [OSTI]

    Brunetto Marco Ziosi; Michela Mapelli; Marica Branchesi; Giuseppe Tormen


    In this paper, we study the formation and dynamical evolution of black hole-black hole (BH-BH) binaries in young star clusters (YSCs), by means of N-body simulations. The simulations include metallicity-dependent recipes for stellar evolution and stellar winds, and have been run for three different metallicities (Z = 0.01, 0.1 and 1 Zsun). Following recent theoretical models of wind mass-loss and core-collapse supernovae, we assume that the mass of the stellar remnants depends on the metallicity of the progenitor stars. We find that BH-BH binaries form efficiently because of dynamical exchanges: in our simulations, we find about 10 times more BH-BH binaries than double neutron star binaries. The simulated BH-BH binaries form earlier in metal-poor YSCs, which host more massive black holes (BHs) than in metal-rich YSCs. The simulated BH-BH binaries have very large chirp masses (up to 80 Msun), because the BH mass is assumed to depend on metallicity, and because BHs can grow in mass due to the merger with stars. The simulated BH-BH binaries span a wide range of orbital periods (10^-3-10^7 yr), and only a small fraction of them (0.3 per cent) is expected to merge within a Hubble time. We discuss the estimated merger rate from our simulations and the implications for Advanced VIRGO and LIGO.

  7. Ultra-high speed burst-mode imager for multi-frame radiography

    SciTech Connect (OSTI)

    Kwiatkowski, Kris [Los Alamos National Laboratory; Nedrow, Paul [Los Alamos National Laboratory; Mariam, Fesseha [Los Alamos National Laboratory; Merrill, Frank E [Los Alamos National Laboratory; Morris, Chris L [Los Alamos National Laboratory; Saunders, Abdy [Los Alamos National Laboratory; Hogan, Gary [Los Alamos National Laboratory; Douance, Vincent [TELEDYNE IMAGING SENSORS; Bal, Yibin [TELEDYNE IMAGING SENSORS; Joshi, Atul [TELEDYNE IMAGING SENSORS; Auyeung, John [TELEDYNE IMAGING SENSORS


    A 720 x 720 pixel hybrid-CMOS imager was fabricated by Rockwell Scientific (now Teledyne Imaging Sensors). Several cameras have been in operation for 5 years, in a variety of static and dynamic experiments, at the 800MeV proton radiography (pRAD) facility at the LANSCE accelerator. The cameras can operate with a per-pulse adjustable inter-frame time of 250ns to 2s, and with an exposure/integration-time as short as 150 ns. Given the 800 ms total readout time, the imager can be externally synchronized to 0.1-to-5Hz, 50-ns wide proton beam pulses, and record 1000-frame radiographic movies of 5-to-30 minute duration. The effectiveness and dependence of the global electronic shutter on the pixelated Si photo-sensor bias voltage is discussed. The spatial resolution dependence of the full imaging system on various monolithic and structured scintillators is presented. We also present features of a new-generation 10-frame, 1024 x 1024 pixel, 50-ns exposure, 12-bit dynamic range imager, which is now in the design phase.

  8. Reconstructing the massive black hole cosmic history through gravitational waves

    E-Print Network [OSTI]

    Alberto Sesana; Jonathan R. Gair; Emanuele Berti; Marta Volonteri


    The massive black holes we observe in galaxies today are the natural end-product of a complex evolutionary path, in which black holes seeded in proto-galaxies at high redshift grow through cosmic history via a sequence of mergers and accretion episodes. Electromagnetic observations probe a small subset of the population of massive black holes (namely, those that are active or those that are very close to us), but planned space-based gravitational-wave observatories such as the Laser Interferometer Space Antenna (LISA) can measure the parameters of ``electromagnetically invisible'' massive black holes out to high redshift. In this paper we introduce a Bayesian framework to analyze the information that can be gathered from a set of such measurements. Our goal is to connect a set of massive black hole binary merger observations to the underlying model of massive black hole formation. In other words, given a set of observed massive black hole coalescences, we assess what information can be extracted about the underlying massive black hole population model. For concreteness we consider ten specific models of massive black hole formation, chosen to probe four important (and largely unconstrained) aspects of the input physics used in structure formation simulations: seed formation, metallicity ``feedback'', accretion efficiency and accretion geometry. For the first time we allow for the possibility of ``model mixing'', by drawing the observed population from some combination of the ``pure'' models that have been simulated. A Bayesian analysis allows us to recover a posterior probability distribution for the ``mixing parameters'' that characterize the fractions of each model represented in the observed distribution. Our work shows that LISA has enormous potential to probe the underlying physics of structure formation.

  9. Artificial ozone holes

    E-Print Network [OSTI]

    S. N. Dolya


    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

  10. Gesturing beyond the Frame: Transnational Trauma and US War Fiction

    E-Print Network [OSTI]

    Lahti, Ruth A. H.


    of Civilians in America’s Wars (New York: Oxford UniversityButler, Judith. Frames of War: When Is Life Grievable? NewRacial Melancholy in Vietnam War Representation. ” Arizona

  11. The Influence of Travelling Fires on a Concrete Frame 

    E-Print Network [OSTI]

    Law, Angus; Stern-Gottfried, Jamie; Gillie, Martin; Rein, Guillermo


    . Current structural fire design methods do not account for these types of fires. This paper applies a novel methodology for defining a family of possible heating regimes to a framed concrete structure using the concept of travelling fires. A finite...

  12. Electromagnetically-Induced Frame-Dragging around Astrophysical Objects

    E-Print Network [OSTI]

    Ruiz, Andrés F Gutiérrez


    Frame dragging (Lense-Thirring effect) is generally associated with rotating astrophysical objects. However, it can also be generated by electromagnetic fields if electric and magnetic fields are simultaneously present. In most models of astrophysical objects, macroscopic charge neutrality is assumed and the entire electromagnetic field is characterized in terms of a magnetic dipole component. Hence, the purely electromagnetic contribution to the frame dragging vanishes. However, strange stars may posses independent electric dipole and neutron stars independent electric quadrupole moments that may lead to the presence of purely electromagnetic contributions to the frame dragging. Moreover, recent observations have shown that in stars with strong electromagnetic fields, the magnetic quadrupole may have a significant contribution to the dynamics of stellar processes. As an attempt to characterized and quantify the effect of electromagnetic frame-dragging in this kind of astrophysical objects, an analytic soluti...

  13. Quantum geometrodynamical description of the Universe in different reference frames

    E-Print Network [OSTI]

    T. P. Shestakova


    Several years ago the so-called quantum geometrodynamics in extended phase space was proposed. The main role in this version of quantum geometrodynamics is given to a wave function that carries information about geometry of the Universe as well as about a reference frame in which this geometry is studied. We consider the evolution of a physical object (the Universe) in ``physical'' subspace of extended configurational space, the latter including gauge and ghost degrees of freedom. A measure of the ``physical'' subspace depends on a chosen reference frame, in particular, a small variation of a gauge-fixing function results in changing the measure. Thus, a transition to another gauge condition (another reference frame) leads to non-unitary transformation of a physical part of the wave function. From the viewpoint of the evolution of the Universe in the ``physical'' subspace a transition to another reference frame is an irreversible process that may be important when spacetime manifold has a nontrivial topology.

  14. Inertial blob-hole symmetry breaking in magnetised plasma filaments

    E-Print Network [OSTI]

    Kendl, Alexander


    Symmetry breaking between the propagation velocities of magnetised plasma filaments with large positive (blob) and negative (hole) amplitudes, as implied by a dimensional analysis scaling, is studied with global ("full-n") non-Boussinesq gyrofluid computations, which include finite inertia effects through nonlinear polarisation. Interchange blobs on a flat density background have higher inertia and propagate more slowly than holes. In the presence of a large enough density gradient, the effect is reversed: blobs accelerate down the gradient and holes are slowed in their propagation up the gradient. Drift wave blobs spread their initial vorticity rapidly into a fully developed turbulent state, whereas primary holes can remain coherent for many eddy turnover times. The results bear implications for plasma edge zonal flow evolution and tokamak scrape-off-layer transport.

  15. Numerical investigation of the threshold for primordial black hole formation

    E-Print Network [OSTI]

    J. C. Niemeyer


    First results of a numerical investigation of primordial black hole formation in the radiation dominated phase of the Early Universe are presented. The simulations follow the gravitational collapse of three different families of high-amplitude density fluctuations imposed at the time of horizon crossing. The threshold for black hole formation, \\delta_{c} \\approx 0.7, is found to be nearly identical for all perturbation families if the control parameter, \\delta, is chosen as the total excess mass within the initial horizon volume. Furthermore, we demonstrate that the scaling of black hole mass with distance from the formation threshold, known to occur in near-critical gravitational collapse, applies to primordial black hole formation.

  16. Black hole evaporation in a noncommutative charged Vaidya model

    SciTech Connect (OSTI)

    Sharif, M., E-mail:; Javed, W. [University of the Punjab, Department of Mathematics (Pakistan)


    We study the black hole evaporation and Hawking radiation for a noncommutative charged Vaidya black hole. For this purpose, we determine a spherically symmetric charged Vaidya model and then formulate a noncommutative Reissner-Nordstroem-like solution of this model, which leads to an exact (t - r)-dependent metric. The behavior of the temporal component of this metric and the corresponding Hawking temperature are investigated. The results are shown in the form of graphs. Further, we examine the tunneling process of charged massive particles through the quantum horizon. We find that the tunneling amplitude is modified due to noncommutativity. Also, it turns out that the black hole evaporates completely in the limits of large time and horizon radius. The effect of charge is to reduce the temperature from a maximum value to zero. We note that the final stage of black hole evaporation is a naked singularity.

  17. Gravitational radiation from dynamical black holes

    E-Print Network [OSTI]

    Sean A. Hayward


    An effective energy tensor for gravitational radiation is identified for uniformly expanding flows of the Hawking mass-energy. It appears in an energy conservation law expressing the change in mass due to the energy densities of matter and gravitational radiation, with respect to a Killing-like vector encoding a preferred flow of time outside a black hole. In a spin-coefficient formulation, the components of the effective energy tensor can be understood as the energy densities of ingoing and outgoing, transverse and longitudinal gravitational radiation. By anchoring the flow to the trapping horizon of a black hole in a given sequence of spatial hypersurfaces, there is a locally unique flow and a measure of gravitational radiation in the strong-field regime.

  18. Formation and Evolution of Galactic Black Holes

    E-Print Network [OSTI]

    F. Combes


    The main requirements for fueling an active galactic nucleus and to form massive black holes are reviewed. Low-luminosity AGN can be fueled easily from the local star clusters, near the nucleus, and the various stellar processes are described. Above a certain luminosity (and therefore accretion rate) large-scale gas flows from galactic scales are required. These can be driven by gravity torques of non-axisymmetric perturbations, such as bars, spirals, galaxy interactions. Observational evidence that these mechanisms are in action is found for high enough luminosities. It is very frequent that starbursts are also triggered through the same mechanisms, and the dense nuclear star clusters formed provide fuel for the AGN over a longer time-scale. Secular internal evolution and more violent evolution through interactions and mergers contribute to grow both a massive black hole and a bulge, and this could explain the observed proportionality relation between the mass of these two components.

  19. Propagating Waves Recorded in the Steel, Moment-Frame Factor Building During Earthquakes

    E-Print Network [OSTI]

    Kohler, Monica; Heaton, Thomas H.; Samuel C. Bradford


    studies of damage to tall steel moment-frame buildings inan instrumented 15-story steel- frame building, EarthquakePropagating Waves in the Steel, Moment-Frame Factor Building

  20. The Ozone Hole Some perspective

    E-Print Network [OSTI]

    Toohey, Darin W.

    The Ozone Hole · Some perspective · The British Antarctic Survey · The "Ozone Hole" · International of the predicted ozone losses! This was quite a controversy. Ultimately, ozone losses started appearing in the late 1980s (see Figure below), but by then, there was already a credibility issue for ozone scientists. #12

  1. Optical black holes and solitons

    E-Print Network [OSTI]

    Shawn Westmoreland


    We exhibit a static, cylindrically symmetric, exact solution to the Euler-Heisenberg field equations (EHFE) and prove that its effective geometry contains (optical) black holes. It is conjectured that there are also soliton solutions to the EHFE which contain black hole geometries.

  2. Black Holes of Negative Mass

    E-Print Network [OSTI]

    R. B. Mann


    I demonstrate that, under certain circumstances, regions of negative energy density can undergo gravitational collapse into a black hole. The resultant exterior black hole spacetimes necessarily have negative mass and non-trivial topology. A full theory of quantum gravity, in which topology-changing processes take place, could give rise to such spacetimes.

  3. Framing bioremediation decision making as negotiation: Rationale & guidelineFraming bioremediation decision making as negotiation: Rationale & guidelines

    SciTech Connect (OSTI)

    Bjornstad, David J.; Wolfe, Amy K.


    Framing remediation decision making as negotiation: (1) social choice, not technology choice; (2) prompts decision makers to identify interested and affected parties, anticipate objections, effectively address and ameliorate objections, and avoid unacceptable decisions.

  4. Usage of Friction-damped Braced Frames for Seismic Vibration Control 

    E-Print Network [OSTI]

    Fink, Brynnan 1992-


    -resisting (portal) frame due only to girder flexibility ...... 19 11 Equivalent spring system for a moment-resisting (portal) frame ......................... 21 12 Moment-resisting (portal) frame modeled in SAP2000 for comparison and deflected shape... system for the right-hand side of braced frame....................... 28 18 Braced frame used in SAP2000 for analysis and comparison.............................. 29 xi FIGURE Page 19 View of cross-braced frame in the plane of motion...

  5. On the black hole limit of rotating discs of charged dust

    E-Print Network [OSTI]

    Martin Breithaupt; Yu-Chun Liu; Reinhard Meinel; Stefan Palenta


    Investigating the rigidly rotating disc of dust with constant specific charge, we find that it leads to an extreme Kerr-Newman black hole in the ultra-relativistic limit. A necessary and sufficient condition for a black hole limit is, that the electric potential in the co-rotating frame is constant on the disc. In that case certain other relations follow. These relations are reviewed with a highly accurate post-Newtonian expansion. Remarkably it is possible to survey the leading order behaviour close to the black hole limit with the post-Newtonian expansion. We find that the disc solution close to that limit can be approximated very well by a "hyper\\-extreme" Kerr-Newman solution with the same gravitational mass, angular momentum and charge.

  6. Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools

    E-Print Network [OSTI]

    Gustavsen, Arild


    contours for one of the PVC frames studied by Gustavsen etframe with a polyvinyl chloride (PVC ) thermal breakand a PVC frame] were examined with air leakage rates of

  7. Black holes with gravitational hair in higher dimensions

    SciTech Connect (OSTI)

    Anabalon, Andres [Departamento de Ciencias Facultad de Artes Liberales, Facultad de Ingenieria y Ciencias, Universidad Adolfo Ibanez, Vina Del Mar (Chile); Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institut, Am Muehlenberg 1 D-14476 Golm (Germany); Canfora, Fabrizio [Centro de Estudios Cientificos (CECS), Casilla 1469 Valdivia (Chile); Giacomini, Alex; Oliva, Julio [Instituto de Ciencias Fisicas y Matematicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia (Chile)


    A new class of vacuum black holes for the most general gravity theory leading to second order field equations in the metric in even dimensions is presented. These space-times are locally anti-de Sitter in the asymptotic region, and are characterized by a continuous parameter that does not enter in the conserve charges, nor it can be reabsorbed by a coordinate transformation: it is therefore a purely gravitational hair. The black holes are constructed as a warped product of a two-dimensional space-time, which resembles the r-t plane of the Banados-Teitelboim-Zanelli black hole, times a warp factor multiplying the metric of a D-2-dimensional Euclidean base manifold, which is restricted by a scalar equation. It is shown that all the Noether charges vanish. Furthermore, this is consistent with the Euclidean action approach: even though the black hole has a finite temperature, both the entropy and the mass vanish. Interesting examples of base manifolds are given in eight dimensions which are products of Thurston geometries, giving then a nontrivial topology to the black hole horizon. The possibility of introducing a torsional hair for these solutions is also discussed.

  8. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Giuseppe Lodato; Priyamvada Natarajan


    In this paper we derive the mass function of seed black holes that result from the central mass concentrated via disc accretion in collapsed haloes at redshift $z\\approx 15$. Using standard arguments including stability, we show that these pre-galactic discs can assemble a significant mass concentration in the inner regions, providing fuel for the formation and initial growth of super-massive black holes. Assuming that these mass concentrations do result in central seed black holes, we determine the mass distribution of these seeds as a function of key halo properties. The seed mass distribution determined here turns out to be asymmetric and skewed to higher masses. Starting with these initial seeds, building up to $10^9$ solar masses by $z = 6$ to power the bright quasars is not a problem in the standard LCDM cosmogony. These seed black holes in gas rich environments are likely to grow into the supermassive black holes at later times via mergers and accretion. Gas accretion onto these seeds at high redshift will produce miniquasars that likely play an important role in the reionization of the Universe. Some of these seed black holes on the other hand could be wandering in galaxy haloes as a consequence of frequent mergers, powering the off-nuclear ultra-luminous X-ray sources detected in nearby galaxies.

  9. Black Hole Remnants and the Information Loss Paradox

    E-Print Network [OSTI]

    Pisin Chen; Yen Chin Ong; Dong-han Yeom


    Forty years after the discovery of Hawking radiation, its exact nature remains elusive. If Hawking radiation does not carry any information out from the ever shrinking black hole, it seems that unitarity is violated once the black hole completely evaporates. On the other hand, attempts to recover information via quantum entanglement lead to the firewall controversy. Amid the confusions, the possibility that black hole evaporation stops with a "remnant" has remained unpopular and is often dismissed due to some "undesired properties" of such an object. Nevertheless, as in any scientific debate, the pros and cons of any proposal must be carefully scrutinized. We fill in the void of the literature by providing a timely review of various types of black hole remnants, and provide some new thoughts regarding the challenges that black hole remnants face in the context of information loss paradox and its latest incarnation, namely the firewall controversy. The importance of understanding the role of curvature singularity is also emphasized, after all there remains a possibility that singularity cannot be cured even by quantum gravity. In this context a black hole remnant conveniently serves as a cosmic censor. We conclude that a remnant remains a possible end state of Hawking evaporation, and if it contains large interior geometry, may help to ameliorate information loss and the firewall paradox. We hope that this will raise some interests in the community to investigate remnants more critically but also more thoroughly.

  10. Non-minimal Higgs inflation and frame dependence in cosmology

    SciTech Connect (OSTI)

    Steinwachs, Christian F. [School of Mathematical Sciences, University of Nottingham University Park, Nottingham, NG7 2RD (United Kingdom); Kamenshchik, Alexander Yu. [Dipartimento di Fisica e Astronomia and INFN, Via Irnerio 46, 40126 Bologna, Italy and L.D. Landau Institute for Theoretical Physics of the Russian Academy of Sciences, Kosygin str. 2, 119334 Moscow (Russian Federation)


    We investigate a very general class of cosmological models with scalar fields non-minimally coupled to gravity. A particular representative in this class is given by the non-minimal Higgs inflation model in which the Standard Model Higgs boson and the inflaton are described by one and the same scalar particle. While the predictions of the non-minimal Higgs inflation scenario come numerically remarkably close to the recently discovered mass of the Higgs boson, there remains a conceptual problem in this model that is associated with the choice of the cosmological frame. While the classical theory is independent of this choice, we find by an explicit calculation that already the first quantum corrections induce a frame dependence. We give a geometrical explanation of this frame dependence by embedding it into a more general field theoretical context. From this analysis, some conceptional points in the long lasting cosmological debate: 'Jordan frame vs. Einstein frame' become more transparent and in principle can be resolved in a natural way.

  11. Probing the Spacetime Around Supermassive Black Holes with Ejected Plasma Blobs

    E-Print Network [OSTI]

    Christian, Pierre


    Millimeter-wavelength VLBI observations of the supermassive black holes in Sgr A* and M87 by the Event Horizon Telescope could potentially trace the dynamics of ejected plasma blobs in real time. We demonstrate that the trajectory and tidal stretching of these blobs can be used to test general relativity and set new constraints on the mass and spin of these black holes.

  12. Navier-Stokes on Black Hole Horizons and DC Thermoelectric Conductivity

    E-Print Network [OSTI]

    Aristomenis Donos; Jerome P. Gauntlett


    We consider a general class of black hole solutions of Einstein-Maxwell theory which are holographically dual to CFTs with spatially dependent sources. We show that an averaged DC thermoelectric conductivity matrix can be obtained by solving the forced, linearised, time-independent Navier-Stokes equations on the black hole horizon for an incompressible and charged fluid.

  13. Navier-Stokes on Black Hole Horizons and DC Thermoelectric Conductivity

    E-Print Network [OSTI]

    Donos, Aristomenis


    We consider a general class of black hole solutions of Einstein-Maxwell theory which are holographically dual to CFTs with spatially dependent sources. We show that an averaged DC thermoelectric conductivity matrix can be obtained by solving the forced, linearised, time-independent Navier-Stokes equations on the black hole horizon for an incompressible and charged fluid.

  14. Strings, higher curvature corrections, and black holes

    E-Print Network [OSTI]

    Thomas Mohaupt


    We review old and recent results on subleading contributions to black hole entropy in string theory.

  15. Alternate Explosions: Collapse and Accretion Events with Red Holes instead of Black Holes

    E-Print Network [OSTI]

    James S. Graber


    A red hole is "just like a black hole" except it lacks an event horizon and a singularity. As a result, a red hole emits much more energy than a black hole during a collapse or accretion event. We consider how a red hole solution can solve the "energy crisis" and power extremely energetic gamma ray bursts and hypernovae.

  16. The Relationship Between Separation Logic and Implicit Dynamic Frames

    E-Print Network [OSTI]

    Parkinson, Matthew J


    Separation logic is a concise method for specifying programs that manipulate dynamically allocated storage. Partially inspired by separation logic, Implicit Dynamic Frames has recently been proposed, aiming at first-order tool support. In this paper, we precisely connect the semantics of these two logics. We define a logic whose syntax subsumes both that of a standard separation logic, and that of implicit dynamic frames as sub-syntaxes. We define a total heap semantics for our logic, and, for the separation logic subsyntax, prove it equivalent the standard partial heaps model. In order to define a semantics which works uniformly for both subsyntaxes, we define the novel concept of a minimal state extension, which provides a different (but equivalent) definition of the semantics of separation logic implication and magic wand connectives, while also giving a suitable semantics for these connectives in implicit dynamic frames. We show that our resulting semantics agrees with the existing definition of weakest p...

  17. Fuel cell repeater unit including frame and separator plate

    DOE Patents [OSTI]

    Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F


    An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

  18. Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities

    E-Print Network [OSTI]

    Gustavsen, Arlid


    window frames; To the left, a PVC window frame (S1) and toaluminum frame, S3 (left) and PVC frame, S4 (right) Figuremade of polyvinyl chloride (PVC) and two of aluminum. For

  19. Density matrix of black hole radiation

    E-Print Network [OSTI]

    Lasma Alberte; Ram Brustein; Andrei Khmelnitsky; A. J. M. Medved


    Hawking's model of black hole evaporation is not unitary and leads to a mixed density matrix for the emitted radiation, while the Page model describes a unitary evaporation process in which the density matrix evolves from an almost thermal state to a pure state. We compare a recently proposed model of semiclassical black hole evaporation to the two established models. In particular, we study the density matrix of the outgoing radiation and determine how the magnitude of the off-diagonal corrections differs for the three frameworks. For Hawking's model, we find power-law corrections to the two-point functions that induce exponentially suppressed corrections to the off-diagonal elements of the full density matrix. This verifies that the Hawking result is correct to all orders in perturbation theory and also allows one to express the full density matrix in terms of the single-particle density matrix. We then consider the semiclassical theory for which the corrections, being non-perturbative from an effective field-theory perspective, are much less suppressed and grow monotonically in time. In this case, the R\\'enyi entropy for the outgoing radiation is shown to grow linearly at early times; but this growth slows down and the entropy eventually starts to decrease at the Page time. In addition to comparing models, we emphasize the distinction between the state of the radiation emitted from a black hole, which is highly quantum, and that of the radiation emitted from a typical classical black body at the same temperature.

  20. Symmetric construction of reference-frame-free qudits

    E-Print Network [OSTI]

    Jun Suzuki; Gelo Noel Macuja Tabia; Berthold-Georg Englert


    By exploiting a symmetric scheme for coupling $N$ spin-1/2 constituents (the physical qubits) to states with total angular momentum $N/2-1$, we construct rotationally invariant logical qudits of dimension $d=N-1$. One can encode all qudit states, and realize all qudit measurements, by this construction. The rotational invariance of all relevant objects enables one to transmit quantum information without having aligned reference frames between the parties that exchange the qudits. We illustrate the method by explicit constructions of reference-frame-free qubits and qutrits and, for the qubit case, comment on possible experimental implementations.

  1. An evaluation of solid state video frame recorders

    SciTech Connect (OSTI)

    Terry, P.L.


    The Department of Energy (DOE) has tasked Sandia with conducting a market survey to identify and evaluate pertinent solid state recorders. This report identifies the chosen recorders and explains why they were selected. It details test procedures and provides the results of the evaluation. Our main focus in this evaluation was to determine whether the frame grabber altered signal quality. To determine the effect on the signal, we evaluated specific parameters: sensitivity, resolution, signal-to-noise ratio, and intrascene dynamic range. These factors were evaluated at the input and output of the frame grabber.

  2. Role of External Flow and Frame Invariance in Stochastic Thermodynamics

    E-Print Network [OSTI]

    Thomas Speck; Jakob Mehl; Udo Seifert


    For configurational changes of soft matter systems affected or caused by external hydrodynamic flow, we identify applied work, exchanged heat, and entropy change on the level of a single trajectory. These expressions guarantee invariance of stochastic thermodynamics under a change of frame of reference. As criterion for equilibrium \\textit{vs.} nonequilibrium, zero \\textit{vs.} nonzero applied work replaces detailed balance \\textit{vs.} nonvanishing currents, since both latter criteria are shown to depend on the frame of reference. Our results are illustrated quantitatively by calculating the large deviation function for the entropy production of a dumbbell in shear flow.

  3. Electromagnetic pulses which have a zero momentum frame

    E-Print Network [OSTI]

    John Lekner


    One set of the Ziolkowski family of exact solutions of the wave equation are shown to represent pulses propagating with momentum smaller than energy/c. This is explicitly demonstrated for special cases by calculating the total electromagnetic momentum and energy. Since the ratio of momentum to energy is a constant smaller than 1/c, there exists a Lorentz transformation to a frame in which the total momentum is zero. In the zero-momentum frame the fields are those of an annular pulse converging onto or diverging from a focal region.

  4. Thermodynamics of regular black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park


    We investigate thermodynamics for a magnetically charged regular black hole (MCRBH), which comes from the action of general relativity and nonlinear electromagnetics, comparing with the Reissner-Norstr\\"om (RN) black hole in both four and two dimensions after dimensional reduction. We find that there is no thermodynamic difference between the regular and RN black holes for a fixed charge $Q$ in both dimensions. This means that the condition for either singularity or regularity at the origin of coordinate does not affect the thermodynamics of black hole. Furthermore, we describe the near-horizon AdS$_2$ thermodynamics of the MCRBH with the connection of the Jackiw-Teitelboim theory. We also identify the near-horizon entropy as the statistical entropy by using the AdS$_2$/CFT$_1$ correspondence.

  5. Numerical analysis of masonry-infilled reinforced concrete frames subjected to seismic loads and experimental evaluation of retrofit techniques

    E-Print Network [OSTI]

    Koutromanos, Ioannis


    infill Load ratio age at testing Concrete frame Infill paneltesting of masonry infilled reinforced concrete frame,” ASCE

  6. Fishing in Black Holes

    E-Print Network [OSTI]

    A. Brotas


    The coordinate system $(\\bar{x},\\bar{t})$ defined by $r = 2m + K\\bar{x}- c K \\bar{t}$ and $t=\\bar{x}/cK - 1 /cK \\int_{r_a}^r (1- 2m/r + K^2)^{1/2} (1 - 2m/r)^{-1}dr$ allow us to write the Schwarzschild metric in the form: \\[ds^2=c^2 d\\bar{t}^2 + (W^2/K^2 - 2W/K) d\\bar{x}^2 + 2c (1 + W/K) d\\bar{x}d\\bar{t} - r^2 (d\\theta^2 + cos^2\\theta d\\phi^2)\\] with $W=(1 - 2m/r + K^2)^{1/2}$, in which the coefficients' pathologies are moved to $r_K = 2m/(1+K^2)$. This new coordinate system is used to study the entrance into a black hole of a rigid line (a line in which the shock waves propagate with velocity c).

  7. Image Framing in Climate Change News Stories, p-1 Image Themes and Frames in U.S. Print News Stories about Climate Change

    E-Print Network [OSTI]

    Hespanha, João Pedro

    Image Framing in Climate Change News Stories, p-1 Image Themes and Frames in U.S. Print News Stories about Climate Change Stacy Rebich-Hespanha, Ronald E. Rice, Daniel R. Montello, Sean Retzloff, Sandrine Tien & João P. Hespanha Research on frames in climate change news coverage has advanced

  8. Electromagnetic pump stator frame having power crossover struts

    DOE Patents [OSTI]

    Fanning, Alan W. (San Jose, CA); Olich, Eugene E. (Aptos, CA)


    A stator frame for an electromagnetic pump includes a casing joined to a hub by a plurality of circumferentially spaced apart struts. At least one electrically insulated power crossover lead extends through the hub, through a crossover one of the struts, and through the casing for carrying electrical current therethrough.

  9. On signal reconstruction from absolute value of frame coefficients

    E-Print Network [OSTI]

    Casazza, Pete

    Edidinb a Siemens Corporate Research, 755 College Road East, Princeton, NJ 08540; b Department transformation from the initial Hilbert space to the space of coefficients obtained by taking the inner product frames, Further author information: Send correspondence to Radu Balan Radu Balan: E-mail: radu.balan@siemens


    E-Print Network [OSTI]

    Benedetto, John J.

    TIGHT FRAMES AND GEOMETRIC PROPERTIES OF WAVELET SETS John J. Benedetto and Songkiat Sumetkijakan # January 29, 2004 1 Introduction 1.1 Background and wavelet sets b R d is Euclidean space, R d , considered of a measurable set K # b R d of finite measure. K # b R d is a wavelet set if the function # # Ÿ 1K is a single

  11. Performance of Wood-Frame Structures during Hurricane Katrina

    E-Print Network [OSTI]

    Cox, Dan

    Performance of Wood-Frame Structures during Hurricane Katrina John W. van de Lindt, M.ASCE1 ; Andrew Graettinger, M.ASCE2 ; Rakesh Gupta, M.ASCE3 ; Thomas Skaggs, M.ASCE4 ; Steven Pryor, M.ASCE5 ; and Kenneth J. Fridley, M.ASCE6 Abstract: The costliest natural disaster in U.S. history was Hurricane Katrina

  12. Jordan frame supergravity and inflation in the NMSSM

    SciTech Connect (OSTI)

    Ferrara, Sergio [Physics Department, Theory Unit, CERN, CH 1211, Geneva 23 (Switzerland); INFN - Laboratori Nazionali di Frascati, Via Enrico Fermi 40, 00044 Frascati (Italy); Kallosh, Renata; Linde, Andrei [Department of Physics, Stanford University, Stanford, California 94305 (United States); Marrani, Alessio; Van Proeyen, Antoine [Instituut voor Theoretische Fysica, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)


    We present a complete explicit N=1, d=4 supergravity action in an arbitrary Jordan frame with nonminimal scalar-curvature coupling of the form {Phi}(z,z)R. The action is derived by suitably gauge fixing the superconformal action. The theory has a modified Kaehler geometry, and it exhibits a significant dependence on the frame function {Phi}(z,z) and its derivatives over scalars, in the bosonic as well as in the fermionic part of the action. Under certain simple conditions, the scalar kinetic terms in the Jordan frame have a canonical form. We consider an embedding of the next-to-minimal supersymmetric standard model (NMSSM) gauge theory into supergravity, clarifying the Higgs inflation model recently proposed by Einhorn and Jones. We find that the conditions for canonical kinetic terms are satisfied for the NMSSM scalars in the Jordan frame, which leads to a simple action. However, we find that the gauge singlet field experiences a strong tachyonic instability during inflation in this model. Thus, a modification of the model is required to support the Higgs-type inflation.


    E-Print Network [OSTI]

    Dillies, Jimmy

    ON ALTERNATE DUAL FRAMES JIMMY DILLIES AND JULIEN GIOL Abstract. The set of alternate duals convenient to introduce the projection pX : l2 (J) - Im X l2 (J) 1 #12;2 JIMMY DILLIES AND JULIEN GIOL onto

  14. Seismic Retrofitting of RC Frames with RC Infilling

    E-Print Network [OSTI]

    Seismic Retrofitting of RC Frames with RC Infilling SERIES Workshop: "Role of research infrastructures in seismic rehabilitation" 8 - 9 February 2012, Istanbul, Turkey C. Z. Chrysostomou, N. Kyriakides, P. Kotronis, P. Roussis, M. Poljansek, F. Taucer RC Infilling of Existing RC Structures for Seismic

  15. Reissner-Nordstrom black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh


    In this paper we propose a stationary solution of Einstein's field equations describing Reissner-Nordstrom black hole in dark energy background. It is to be regarded as the Reissner-Nordstrom black hole is embedded into the dark energy solution producing Reissner-Nordstrom-dark energy black hole. We find that the space-time geometry of Reissner-Nordstrom-dark energy solution is Petrov type $D$ in the classification of space-times. It is also shown that the embedded space-time possesses an energy-momentum tensor of the electromagnetic field interacting with the dark energy having negative pressure. We find the energy-momentum tensor for dark energy violates the the strong energy condition due to the negative pressure, whereas that of the electromagnetic field obeys the strong energy condition. It is shown that the time-like vector field for an observer in the Reissner-Nordstrom-dark energy space is expanding, accelerating, shearing and non-rotating. We investigate the surface gravity of the horizons for the embedded dark energy black hole. The characteristic properties of relativistic dark energy based on the de Sitter solution is discussed in an appendix.

  16. Comment on "Formation of Holes in Alkanethiol Monolayers on Gold"

    E-Print Network [OSTI]

    Myrick, Michael Lenn

    microscopy (STM) images of al- kanethiolate monolayers on gold, one type of defect appears which does concentration.1 Fifth, the evolution of the holes appears to cease once the self-assembled monolayer (SAM) has the surface. They are not usually found very near existing step defects, and time-resolved STM images

  17. Charged black holes in expanding Einstein-de Sitter universes

    E-Print Network [OSTI]

    Manuela G. Rodrigues; Vilson T. Zanchin


    Inspired in a previous work by McClure and Dyer (Classical Quantum Gravity 23, 1971 (2006)), we analyze some solutions of the Einstein-Maxwell equations which were originally written to describe charged black holes in cosmological backgrounds. A detailed analysis of the electromagnetic sources for a sufficiently general metric is performed, and then we focus on deriving the electromagnetic four-current as well as the conserved electric charge of each metric. The charged McVittie solution is revisited and a brief study of its causal structure is performed, showing that it may represent a charged black hole in an expanding universe, with the black hole horizon being formed at infinite late times. Charged versions of solutions originally put forward by Vaidya (Vd) and Sultana and Dyer (SD) are also analyzed. It is shown that the charged Sultana-Dyer metric requires a global electric current, besides a central (pointlike) electric charge. With the aim of comparing to the charged McVittie metric, new charged solutions of Vd and SD type are considered. In these cases, the original mass and charge parameters are replaced by particular functions of the cosmological time. In the new generalized charged Vaidya metric the black hole horizon never forms, whereas in the new generalized Sultana-Dyer case both the Cauchy and the black hole horizons develop at infinite late times. A charged version of the Thakurta metric is also studied here. It is also a new solution. As in the charged Sultana-Dyer case, the natural source of the electromagnetic field is a central electric charge with an additional global electric current. The global structure is briefly studied and it is verified that the corresponding spacetime may represent a charged black hole in a cosmological background. All the solutions present initial singularities as found in the McVittie metric.

  18. Relativity of Space-Time Geometry

    E-Print Network [OSTI]

    L. V. Verozub


    We argue that space-time geometry is not absolute with respect to the frame of reference being used. The space-time metric differential form $ds$ in noninertial frames of reference (NIFR) is caused by the properties of the used frames in accordance with the Berkley - Leibnitz - Mach - Poincar\\'{e} ideas about relativity of space and time . It is shown that the Sagnac effect and the existence of inertial forces in NIFR can be considered from this point of view. An experimental test is proposed.

  19. Feedback Limits Rapid Growth of Seed Black Holes at High Redshift

    E-Print Network [OSTI]

    J. -M. Wang; Y. -M. Chen; C. Hu


    Seed black holes formed in the collapse of population III stars have been invoked to explain the presence of supermassive black holes at high redshift. It has been suggested that a seed black hole can grow up to $10^{5\\sim 6}\\sunm$ through highly super-Eddington accretion for a period of $\\sim 10^{6\\sim 7}$ yr between redshift $z=20\\sim 24$. We studied the feedback of radiation pressure, Compton heating and outflow during the seed black hole growth. It is found that its surrounding medium fueled to the seed hole is greatly heated by Compton heating. For a super-critical accretion onto a $10^3\\sunm$ seed hole, a Compton sphere (with a temperature $\\sim 10^6$K) forms in a timescale of $1.6\\times 10^3$yr so that the hole is only supplied by a rate of $10^{-3}$ Eddington limit from the Compton sphere. Beyond the Compton sphere, the kinetic feedback of the strong outflow heats the medium at large distance, this leads to a dramatical decrease of the outer Bondi accretion onto the black hole and avoid the accumulation of the matter. The highly super-critical accretion will be rapidly halted by the strong feedback. The seed black holes hardly grow up at the very early universe unless the strong feedback can be avoided.

  20. Thermal performance of steel-framed walls. Final report

    SciTech Connect (OSTI)

    Barbour, E. [NAHB Research Center, Inc., Upper Marlboro, MD (United States); Goodrow, J. [Holometrix, Inc., Bedford, MA (United States); Kosny, J.; Christian, J.E. [Oak Ridge National Lab., TN (United States)


    In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.

  1. Construction of a Penrose Diagram for an Accreting Black Hole

    E-Print Network [OSTI]

    Beth A. Brown; James Lindesay


    A Penrose diagram is constructed for a spatially coherent black hole that accretes at stepwise steady rates as measured by a distant observer from an initial state described by a metric of Minkowski form. Coordinate lines are computationally derived, and radial light-like trajectories verify the viability of the diagram. Coordinate dependencies of significant features, such as the horizon and radial mass scale, are clearly demonstrated on the diagram. The onset of a singularity at the origin is shown to open a new region in space-time that contains the interior of the black hole.

  2. Energy Associated with Schwarzschild Black Hole in a Magnetic Universe

    E-Print Network [OSTI]

    S. S. Xulu


    In this paper we obtain the energy distribution associated with the Ernst space-time (geometry describing Schwarzschild black hole in Melvin's magnetic universe) in Einstein's prescription. The first term is the rest-mass energy of the Schwarzschild black hole, the second term is the classical value for the energy of the uniform magnetic field and the remaining terms in the expression are due to the general relativistic effect. The presence of the magnetic field is found to increase the energy of the system.

  3. Do Supermassive Black Holes Exist at the Center of Galaxies?

    E-Print Network [OSTI]

    J. W. Moffat


    Models of superdense star clusters at the center of galaxies are investigated to see whether such objects can be stable and long-lived based on evaporation and collision time-scales and stability criteria. We find that physically reasonable models of massive clusters of stellar remnants can exist with masses $\\geq 10^6 M_{\\odot}$, which could simulate black holes at the center of galaxies with large $M/L$ ratios and gas motions of order $\\geq 10^3$ km $s^{-1}$. It follows that the evidence is not conclusive for massive dark objects at the center of galaxies being black holes.

  4. Isolated Horizons: A Generalization of Black Hole Mechanics

    E-Print Network [OSTI]

    Abhay Ashtekar; Christopher Beetle; Stephen Fairhurst


    A set of boundary conditions defining a non-rotating isolated horizon are given in Einstein-Maxwell theory. A space-time representing a black hole which itself is in equilibrium but whose exterior contains radiation admits such a horizon . Physically motivated, (quasi-)local definitions of the mass and surface gravity of an isolated horizon are introduced. Although these definitions do not refer to infinity, the quantities assume their standard values in Reissner-Nordstrom solutions. Finally, using these definitions, the zeroth and first laws of black hole mechanics are established for isolated horizons.

  5. Fate of Yang-Mills black hole in early Universe

    SciTech Connect (OSTI)

    Nakonieczny, Lukasz; Rogatko, Marek [Institute of Physics Maria Curie-Sklodowska University 20-031 Lublin, pl. Marii Curie-Sklodowskiej 1 (Poland)


    According to the Big Bang Theory as we go back in time the Universe becomes progressively hotter and denser. This leads us to believe that the early Universe was filled with hot plasma of elementary particles. Among many questions concerning this phase of history of the Universe there are questions of existence and fate of magnetic monopoles and primordial black holes. Static solution of Einstein-Yang-Mills system may be used as a toy model for such a black hole. Using methods of field theory we will show that its existence and regularity depend crucially on the presence of fermions around it.

  6. A photometric method to determine supermassive black hole masses

    E-Print Network [OSTI]

    A. W. Graham; P. Erwin; N. Caon; I. Trujillo


    We report the discovery of a strong correlation between the shape of a bulge's light-profile and the mass of its central supermassive black hole (M_{bh}). We find that log(M_{bh}/M_{sun}) = 2.91(+/-0.38)log(n) + 6.37(+/-0.21), where `n' is the Sersic r^{1/n} shape index of the bulge. This correlation is marginally stronger than the relationship between the logarithm of the stellar velocity dispersion and log(M_{bh}) and has comparable scatter. It therefore offers a cheap (in terms of telescope time) alternative to estimating the masses of supermassive black holes.

  7. Supercurrent: Vector Hair for an AdS Black Hole

    E-Print Network [OSTI]

    Pallab Basu; Anindya Mukherjee; Hsien-Hang Shieh


    In arXiv:0803.3295 [hep-th] a holographic black hole solution is discussed which exhibits a superconductor like transition. In the superconducting phase the black holes show infinite DC conductivity. This gives rise to the possibility of deforming the solutions by turning on a time independent current (supercurrent), without any electric field. This type of deformation does not exist for normal (non-superconducting) black holes, due to the no-hair theorems. In this paper we have studied such a supercurrent solution and the associated phase diagram. Interestingly, we have found a "special point" (critical point) in the phase diagram where the second order superconducting phase transition becomes first order. Supercurrent in superconducting materials is a well studied phenomenon in condensed matter systems. We have found some qualitative agreement with known results.

  8. A scale-free analysis of magnetic holes in the solar wind

    E-Print Network [OSTI]

    Stevens, M. L. (Michael Louis)


    Magnetic holes are isolated intervals of depleted interplanetary magnetic field (IMF) strength on timescales of several seconds to several hours. These intervals have been seen as often as several times per day in the ...

  9. Slant hole completion test (1991) sidetrack ``as built`` report

    SciTech Connect (OSTI)

    Myal, F.R.


    During the summer of 1990, a slant hole test well, funded by the US Department of Energy, was drilled to 9,466 ft to evaluate the effectiveness of directional drilling in the tight, naturally fractured gas sands and coals of the Mesaverde Group. The surface location of the SHCT No. 1 is 700 ft south of the DOE Multiwell Experiment (MWX) site in Section 34, T6S, R94W, Garfield County, Colorado, approximately 7.5 miles west of Rifle. Mechanical problems following cementing of a production liner resulted in loss of the completion interval, and operations were suspended. In early 1991, DOE decided to sidetrack the hole to permit production testing of the lost interval. The sidetrack was designed to parallel the original wellbore, but to be drilled 1,000 ft to the east to minimize the chances of encountering formation damage from the original hole. The sidetrack, like the original hole, was to intersect the paludal lenticular sands and coals at 60{degrees} and to penetrate the underlying Cozzette sand horizonally. The sidetrack was spudded May 12, 1991. After re-entering the well in late 1991, early production testing of the Cozzette showed that the 300 ft of in-pay horizontal hole can produce at rate 5 to 10 times higher than vertical wells in the same area. This report contains the geological summary and sidetrack drilling operations summary.

  10. Slant hole completion test (1991) sidetrack as built'' report

    SciTech Connect (OSTI)

    Myal, F.R.


    During the summer of 1990, a slant hole test well, funded by the US Department of Energy, was drilled to 9,466 ft to evaluate the effectiveness of directional drilling in the tight, naturally fractured gas sands and coals of the Mesaverde Group. The surface location of the SHCT No. 1 is 700 ft south of the DOE Multiwell Experiment (MWX) site in Section 34, T6S, R94W, Garfield County, Colorado, approximately 7.5 miles west of Rifle. Mechanical problems following cementing of a production liner resulted in loss of the completion interval, and operations were suspended. In early 1991, DOE decided to sidetrack the hole to permit production testing of the lost interval. The sidetrack was designed to parallel the original wellbore, but to be drilled 1,000 ft to the east to minimize the chances of encountering formation damage from the original hole. The sidetrack, like the original hole, was to intersect the paludal lenticular sands and coals at 60{degrees} and to penetrate the underlying Cozzette sand horizonally. The sidetrack was spudded May 12, 1991. After re-entering the well in late 1991, early production testing of the Cozzette showed that the 300 ft of in-pay horizontal hole can produce at rate 5 to 10 times higher than vertical wells in the same area. This report contains the geological summary and sidetrack drilling operations summary.

  11. Universal cell frame for high-pressure water electrolyzer and electrolyzer including the same

    DOE Patents [OSTI]

    Schmitt, Edwin W.; Norman, Timothy J.


    Universal cell frame generic for use as an anode frame and as a cathode frame in a water electrolyzer. According to one embodiment, the universal cell frame includes a unitary annular member having a central opening. Four trios of transverse openings are provided in the annular member, each trio being spaced apart by about 90 degrees. A plurality of internal radial passageways fluidly interconnect the central opening and each of the transverse openings of two diametrically-opposed trios of openings, the other two trios of openings lacking corresponding radial passageways. Sealing ribs are provided on the top and bottom surfaces of the annular member. The present invention is also directed at a water electrolyzer that includes two such cell frames, one being used as the anode frame and the other being used as the cathode frame, the cathode frame being rotated 90 degrees relative to the anode frame.

  12. The Synchronic Frame of Photospheric Magnetic Flux: The Improved Synoptic Frame

    E-Print Network [OSTI]

    Zhao, Xuepu

    of the middle panel). Because of the differential rotation of magnetic elements, the solar surface distribution from a synoptic chart do not cover the whole solar surface at any time within the period of one solar transpot models to predict better instantaneous photospheric field distribution on the portions of solar

  13. Heat Engine of black holes

    E-Print Network [OSTI]

    Sadeghi, J


    As we know, the cosmological constant in different theories of gravity acts as a thermodynamics variable. The cosmological constant exists in different actions of gravity and also appears in the solution of such theories. These lead to use the black hole as a heat engines. Also, there are two values for the cosmological constant as positive and negative values. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. In this paper, we are going to define heat engines for two different black holes as Dyonic BH and Kerr BH. And also, we calculate maximum efficiency for two black holes.

  14. Heat Engine of black holes

    E-Print Network [OSTI]

    J. Sadeghi; Kh. Jafarzade


    As we know, the cosmological constant in different theories of gravity acts as a thermodynamics variable. The cosmological constant exists in different actions of gravity and also appears in the solution of such theories. These lead to use the black hole as a heat engines. Also, there are two values for the cosmological constant as positive and negative values. The case of negative cosmological constant supplies a natural realization of these engines in terms of the field theory description of the fluids to which they are holographically dual. In this paper, we are going to define heat engines for two different black holes as Dyonic BH and Kerr BH. And also, we calculate maximum efficiency for two black holes.

  15. Quantum Black Hole Formation in the BFSS Matrix Model

    E-Print Network [OSTI]

    Sinya Aoki; Masanori Hanada; Norihiro Iizuka


    We study the various head-on collisions of two bunches of D0-branes and their real-time evolution in the BFSS matrix model in classical limit. For a various matrix size N respecting the 't Hooft scaling, we find quantitative evidence for the formation of a single bound state of D0-branes at late time, which is matrix model thermalization and dual to the formation of a larger black hole.

  16. Horizon dynamics of distorted rotating black holes

    E-Print Network [OSTI]

    Tony Chu; Harald P. Pfeiffer; Michael I. Cohen


    We present numerical simulations of a Kerr black hole perturbed by a pulse of ingoing gravitational radiation. For strong perturbations we find up to five concentric marginally outer trapped surfaces. These trapped surfaces appear and disappear in pairs, so that the total number of such surfaces at any given time is odd. The world tubes traced out by the marginally outer trapped surfaces are found to be spacelike during the highly dynamical regime, approaching a null hypersurface at early and late times. We analyze the structure of these marginally trapped tubes in the context of the dynamical horizon formalism, computing the expansion of outgoing and incoming null geodesics, as well as evaluating the dynamical horizon flux law and the angular momentum flux law. Finally, we compute the event horizon. The event horizon is well-behaved and approaches the apparent horizon before and after the highly dynamical regime. No new generators enter the event horizon during the simulation.

  17. Absolute conservation law for black holes

    E-Print Network [OSTI]

    D. Grumiller; W. Kummer


    In all 2d theories of gravity a conservation law connects the (space-time dependent) mass aspect function at all times and all radii with an integral of the matter fields. It depends on an arbitrary constant which may be interpreted as determining the initial value together with the initial values for the matter field. We discuss this for spherically reduced Einstein-gravity in a diagonal metric and in a Bondi-Sachs metric using the first order formulation of spherically reduced gravity, which allows easy and direct fixations of any type of gauge. The relation of our conserved quantity to the ADM and Bondi mass is investigated. Further possible applications (ideal fluid, black holes in higher dimensions or AdS spacetimes etc.) are straightforward generalizations.

  18. Entropy: From Black Holes to Ordinary Systems

    E-Print Network [OSTI]

    J. P. Badiali


    Several results of black holes thermodynamics can be considered as firmly founded and formulated in a very general manner. From this starting point we analyse in which way these results may give us the opportunity to gain a better understanding in the thermodynamics of ordinary systems for which a pre-relativistic description is sufficient. First, we investigated the possibility to introduce an alternative definition of the entropy basically related to a local definition of the order in a spacetime model rather than a counting of microstates. We show that such an alternative approach exists and leads to the traditional results provided an equilibrium condition is assumed. This condition introduces a relation between a time interval and the reverse of the temperature. We show that such a relation extensively used in the black hole theory, mainly as a mathematical trick, has a very general and physical meaning here; in particular its derivation is not related to the existence of a canonical density matrix. Our dynamical approach of thermodynamic equilibrium allows us to establish a relation between action and entropy and we show that an identical relation exists in the case of black holes. The derivation of such a relation seems impossible in the Gibbs ensemble approach of statistical thermodynamics. From these results we suggest that the definition of entropy in terms of order in spacetime should be more general that the Boltzmann one based on a counting of microstates. Finally we point out that these results are obtained by reversing the traditional route going from the Schr\\"{o}dinger equation to statistical thermodynamics.

  19. Photoionization microscopy in terms of local frame transformation theory

    E-Print Network [OSTI]

    P. Giannakeas; F. Robicheaux; Chris H. Greene


    Two-photon ionization of an alkali-metal atom in the presence of a uniform electric field is investigated using a standardized form of local frame transformation and generalized quantum defect theory. The relevant long-range quantum defect parameters in the combined Coulombic plus Stark potential is calculated with eigenchannel R-matrix theory applied in the downstream parabolic coordinate $\\eta$. The present formulation permits us to express the corresponding microscopy observables in terms of the local frame transformation, and it gives a critical test of the accuracy of the Harmin-Fano theory permitting a scholastic investigation of the claims presented in Zhao {\\it et al.} [Phys. Rev. A 86, 053413 (2012)].

  20. Dark energy rest frame and the CMB dipole

    E-Print Network [OSTI]

    Antonio L. Maroto


    If dark energy can be described as a perfect fluid, then, apart from its equation of state relating energy density and pressure, we should also especify the corresponding rest frame. Since dark energy is typically decoupled from the rest of components of the universe, in principle such a frame could be different from that of matter and radiation. In this work we consider the potential observable effects of the motion of dark energy and the possibility to measure the dark energy velocity relative to matter. In particular we consider the modification of the usual interpretation of the CMB dipole and its implications for the determination of matter bulk flows on very large scales. We also comment on the possible origin of a dark energy flow and its evolution in different models.

  1. Introduction to Black Hole Evaporation

    E-Print Network [OSTI]

    Pierre-Henry Lambert


    These lecture notes are an elementary and pedagogical introduction to the black hole evaporation, based on a lecture given by the author at the Ninth Modave Summer School in Mathematical Physics and are intended for PhD students. First, quantum field theory in curved spacetime is studied and tools needed for the remaining of the course are introduced. Then, quantum field theory in Rindler spacetime in 1+1 dimensions and in the spacetime of a spherically collapsing star are considered, leading to Unruh and Hawking effects, respectively. Finally, some consequences such as thermodynamics of black holes and information loss paradox are discussed.

  2. Use of explosives to demolish multistory steel frame buildings

    E-Print Network [OSTI]

    Landry, Charles Vernon


    of Explosives Engineers. The articles dealt with the state-of-the-art, covering many peripheral subjects of the use of explosives to demolish steel framed multistory buildings. The most extensive literature available on controlled demolition techniques... with the exception of several articles presented to the Annual Proceedings of the Society of Explosives Engineers and a few U. S. government studies on the use of explosives. In depth interviews were conducted with controlled explosive demolition companies...

  3. Relativistic addition of parallel velocities from time dilation

    E-Print Network [OSTI]

    Bernhard Rothenstein; Stefan Popescu


    The relativistic addition of parallel velocities is derived involving relativity only via the time dilation formula, avoiding the length contraction used by many authors in conjunction with time dilation. The followed scenario involves a machine gun that fires successive bullets, considered from its rest frame and from the rest frame of the target, the bullets hit.

  4. Hawking Emission and Black Hole Thermodynamics

    E-Print Network [OSTI]

    Don N. Page


    A brief review of Hawking radiation and black hole thermodynamics is given, based largely upon hep-th/0409024.

  5. A quantum peek inside the black hole event horizon

    E-Print Network [OSTI]

    Sumanta Chakraborty; Suprit Singh; T. Padmanabhan


    We solve the Klein-Gordon equation for a scalar field, in the background geometry of a dust cloud collapsing to form a black hole, everywhere in the (1+1) spacetime: that is, both inside and outside the event horizon and arbitrarily close to the curvature singularity. This allows us to determine the regularized stress tensor expectation value, everywhere in the appropriate quantum state (viz., the Unruh vacuum) of the field. We use this to study the behaviour of energy density and the flux measured in local inertial frames for the radially freely falling observer at any given event. Outside the black hole, energy density and flux lead to the standard results expected from the Hawking radiation emanating from the black hole, as the collapse proceeds. Inside the collapsing dust ball, the energy densities of both matter and scalar field diverge near the singularity in both (1+1) and (1+3) spacetime dimensions; but the energy density of the field dominates over that of classical matter. In the (1+3) dimensions, the total energy (of both scalar field and classical matter) inside a small spatial volume around the singularity is finite (and goes to zero as the size of the region goes to zero) but the total energy of the quantum field still dominates over that of the classical matter. Inside the event horizon, but \\textit{outside} the collapsing matter, freely falling observers find that the energy density and the flux diverge close to the singularity. In this region, even the integrated energy inside a small spatial volume enclosing the singularity diverges. This result holds in both (1+1) and (1+3) spacetime dimensions with a \\emph{milder} divergence for the total energy inside a small region in (1+3) dimensions. These results suggest that the back-reaction effects are significant even in the region \\emph{outside the matter but inside the event horizon}, close to the singularity.

  6. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.


    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  7. Signatures of black holes at the LHC

    E-Print Network [OSTI]

    Marco Cavaglia; Romulus Godang; Lucien M. Cremaldi; Donald J. Summers


    Signatures of black hole events at CERN's Large Hadron Collider are discussed. Event simulations are carried out with the Fortran Monte Carlo generator CATFISH. Inelasticity effects, exact field emissivities, color and charge conservation, corrections to semiclassical black hole evaporation, gravitational energy loss at formation and possibility of a black hole remnant are included in the analysis.

  8. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.


    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  9. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.


    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  10. Absorption cross section in Lifshitz black hole

    E-Print Network [OSTI]

    Taeyoon Moon; Yun Soo Myung


    We derive the absorption cross section of a minimally coupled scalar in the Lifshitz black hole obtained from the new massive gravity. The absorption cross section reduces to the horizon area in the low energy and massless limit of s-wave mode propagation, indicating that the Lifshitz black hole also satisfies the universality of low energy absorption cross section for black holes.

  11. Black holes in f(R) theories

    SciTech Connect (OSTI)

    Cruz-Dombriz, A. de la; Dobado, A.; Maroto, A. L. [Departamento de Fisica Teorica I, Universidad Complutense de Madrid, 28040 Madrid (Spain)


    In the context of f(R) theories of gravity, we address the problem of finding static and spherically symmetric black hole solutions. Several aspects of constant curvature solutions with and without electric charge are discussed. We also study the general case (without imposing constant curvature). Following a perturbative approach around the Einstein-Hilbert action, it is found that only solutions of the Schwarzschild-(anti) de Sitter type are present up to second order in perturbations. Explicit expressions for the effective cosmological constant are obtained in terms of the f(R) function. Finally, we have considered the thermodynamics of black holes in anti-de Sitter space-time and found that this kind of solution can only exist provided the theory satisfies R{sub 0}+f(R{sub 0})<0. Interestingly, this expression is related to the condition which guarantees the positivity of the effective Newton's constant in this type of theories. In addition, it also ensures that the thermodynamical properties in f(R) gravities are qualitatively similar to those of standard general relativity.

  12. Black hole free energy during charged collapse: a numerical study

    E-Print Network [OSTI]

    Hugues Beauchesne; Ariel Edery


    We perform a numerical investigation of the thermodynamics during the collapse of a charged (complex) scalar field to a Reissner-Nordstr\\"om (RN) black hole in isotropic coordinates. Numerical work on gravitational collapse in isotropic coordinates has recently shown that the negative of the total Lagrangian approaches the Helmholtz free energy F= E-TS of a Schwarzschild black hole at late times of the collapse (where E is the black hole mass, T the temperature and S the entropy). The relevant thermodynamic potential for the RN black hole is the Gibbs free energy G=E-TS-$\\Phi_H$ Q where Q is the charge and $\\Phi_H$ the electrostatic potential at the outer horizon. In charged collapse, there is a large outgoing matter wave which prevents the exterior from settling quickly to a static state. However, the interior region is not affected significantly by the wave. We find numerically that the interior contribution to the Gibbs free energy is entirely gravitational and accumulates in a thin shell just inside the horizon. The entropy is gravitational in origin and one observes dynamically that it resides on the horizon. We also compare the numerical value of the interior Lagrangian to the expected analytical value of the interior Gibbs free energy for different initial states and we find that they agree to within 10-13%. The two values are approaching each other so that their difference decreases with more evolution time.

  13. Einstein, Black Holes Gravitational Waves

    E-Print Network [OSTI]

    Cook, Greg

    1 #12;Einstein, Black Holes and Gravitational Waves Gregory B. Cook Wake Forest University 2 #12;Einstein's Miraculous Year: 1905 · Einstein, A. "¨Uber einen die Erzeugung und Verwandlung des Lichtes Concerning the Production and Transformation of Light. · Einstein, A. "¨Uber die von der molekularkinetischen

  14. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)


    Pinhole photography has made major contributions to astrophysics through the use of “coded apertures”. Coded apertures were instrumental in locating gamma-ray bursts and proving that they originate in faraway galaxies, some from the birth of black holes from the first stars that formed just after the big bang.

  15. Stability of Horava-Lifshitz Black Holes in the Context of AdS/CFT

    SciTech Connect (OSTI)

    Ong, Yen Chin; /Taiwan, Natl. Taiwan U.; Chen, Pisin; /Taiwan, Natl. Taiwan U. /KIPAC, Menlo Park /SLAC


    The anti-de Sitter/conformal field theory (AdS/CFT) correspondence is a powerful tool that promises to provide new insights toward a full understanding of field theories under extreme conditions, including but not limited to quark-gluon plasma, Fermi liquid, and superconductor. In many such applications, one typically models the field theory with asymptotically AdS black holes. These black holes are subjected to stringy effects that might render them unstable. Horava-Lifshitz gravity, in which space and time undergo different transformations, has attracted attention due to its power-counting renormalizability. In terms of AdS/CFT correspondence, Horava-Lifshitz black holes might be useful to model holographic superconductors with Lifshitz scaling symmetry. It is thus interesting to study the stringy stability of Horava-Lifshitz black holes in the context of AdS/CFT. We find that uncharged topological black holes in {lambda} = 1 Horava-Lifshitz theory are nonperturbatively stable, unlike their counterparts in Einstein gravity, with the possible exceptions of negatively curved black holes with detailed balance parameter {epsilon} close to unity. Sufficiently charged flat black holes for {epsilon} close to unity, and sufficiently charged positively curved black holes with {epsilon} close to zero, are also unstable. The implication to the Horava-Lifshitz holographic superconductor is discussed.

  16. Key Elements of and Materials Performance Targets for Highly Insulating Window Frames

    E-Print Network [OSTI]

    Gustavsen, Arild


    in light green. 2.5 Window Frame E (PVC) Window frame Eis polyvinyl chloride (PVC). We performed calculations forspacer = 0.25?0.1 W/(mK) ? pvc = 0.9 W/(mK), ? eff. ,spacer

  17. A study of owner preferences for steel and wood framed homes 

    E-Print Network [OSTI]

    Bateman, Bruce Whitney


    that purchased steel framed homes (SFHS) and those households that purchased wood framed homes (WFHs). The objectives of the study were (1) to determine if there were any significant differences in the demographic profiles of the two study groups, (2...

  18. Conflicting Frames : the dispute over the meaning of rolezinhos in Brazilian media

    E-Print Network [OSTI]

    Goncalves, Alexandre A


    This research analyzes the battle of frames in the controversy surrounding rolezinhos- flashmobs organized by low-income youth in Brazilian shopping malls. To analyze the framing of these events, a corpus of 4,523 online ...

  19. Analytical Modeling of Wood Frame Shear Walls Subjected to Vertical Load

    E-Print Network [OSTI]

    Nguyendinh, Hai


    referred to as Analytical Model of wood frame SHEar walls subjected to Vertical load (AMSHEV) is based on the kinematic behavior of wood frame shear walls and captures significant characteristics observed from experimental testing through appropriate...

  20. Seismic vulnerability of older reinforced concrete frame structures in Mid-America

    E-Print Network [OSTI]

    Beason, Lauren Rae


    This research quantifies the seismic vulnerability of older reinforced concrete frame structures located in Mid-America. After designing a representative three-story gravity load designed reinforced concrete frame structure, a nonlinear analytical...

  1. Computational Fracture Prediction in Steel Moment Frame Structures with the Application of Artificial Neural Networks

    E-Print Network [OSTI]

    Long, Xiao


    performance of moment frames. Without such a model, the aforementioned problem can never be resolved. This dissertation develops an innovative way of predicting cyclic rupture in steel moment frames by employing artificial neural networks. First, finite...

  2. Identification, Model Updating, and Response Prediction of an Instrumented 15-Story Steel-Frame Building

    E-Print Network [OSTI]

    Skolnik, Derek; Lei, Ying; Yu, Eunjong; Wallace, J W


    A. , 1998. Ductile Design of Steel Structure, McGraw Hill,monitoring of the steel-frame UCLA Factor Building,an Instrumented 15-Story Steel-Frame Building Derek Skolnik,

  3. The lifetime problem of evaporating black holes: mutiny or resignation

    E-Print Network [OSTI]

    Carlos Barceló; Raúl Carballo-Rubio; Luis J. Garay; Gil Jannes


    It is logically possible that regularly evaporating black holes exist in nature. In fact, the prevalent theoretical view is that these are indeed the real objects behind the curtain in astrophysical scenarios. There are several proposals for regularizing the classical singularity of black holes so that their formation and evaporation do not lead to information-loss problems. One characteristic is shared by most of these proposals: these regularly evaporating black holes present long-lived trapping horizons, with absolutely enormous evaporation lifetimes in whatever measure. Guided by the discomfort with these enormous and thus inaccessible lifetimes, we elaborate here on an alternative regularization of the classical singularity, previously proposed by the authors in an emergent gravity framework, which leads to a completely different scenario. In our scheme the collapse of a stellar object would result in a genuine time-symmetric bounce, which in geometrical terms amounts to the connection of a black-hole geometry with a white-hole geometry in a regular manner. The two most differential characteristics of this proposal are: i) the complete bouncing geometry is a solution of standard classical general relativity everywhere except in a transient region that necessarily extends beyond the gravitational radius associated with the total mass of the collapsing object; and ii) the duration of the bounce as seen by external observers is very brief (fractions of milliseconds for neutron-star-like collapses). This scenario motivates the search for new forms of stellar equilibrium different from black holes. In a brief epilogue we compare our proposal with a similar geometrical setting recently proposed by Haggard and Rovelli.

  4. Variational Results and Solutions in Gauge Gravity and a Bifurcation Analysis of Black Hole Orbital Dynamics

    E-Print Network [OSTI]

    Bruce Herold Dean


    An analysis of all known spherically symmetric solutions to the field equations originating from the Riemann tensor quadratic curvature Lagrangian is presented. A new exact solution is found for the field equation originating from the "energy-momentum" equation of the gauge gravity theory. Imposing equivalence between the Palatini and standard variational field equations yields an algebraic condition that restricts the number spacetime solutions to gauge gravity. An analysis of a new spherically symmetric solution to the conformal gravity field equations is also presented. Point particle orbital dynamics in both the Schwarzschild and Reissner-Nordstrom black hole spacetimes are analyzed as 2-d conservative bifurcation phenomena. The Schwarzschild dynamics exhibit both saddle-center and transcritical bifurcation points and a calculation of periastron precession is presented that incorporates a phase-plane analysis of the relativistic equations of motion. Level curves of constant energy are illustrated for both timelike and null geodesics and a phase-plane analysis of dynamical invariance between the proper and coordinate time reference frames is discussed. The Reissner-Nordstrom dynamics exhibit saddle-center, transcritical, pseudo-transcritical, and additional bifurcations that combine all three previous bifurcations in various combinations. Periastron precession in the Reissner-Nordstrom spacetime is analyzed using the phase-plane and bifurcation techniques and extended to include a bifurcation point of the dynamics. A numerical solution at these parameter values illustrates that such orbits typically yield a much larger precession value compared to the standard value for timelike, precession. The acausal geodesics considered by Brigman are also discussed and their precession value is calculated.

  5. Center-of-mass energy for the Plebanski-Demianski black hole

    SciTech Connect (OSTI)

    Sharif, M., E-mail:; Haider, Nida, E-mail: [University of the Punjab, Department of Mathematics (Pakistan)] [University of the Punjab, Department of Mathematics (Pakistan)


    We study the center-of-mass energy of the particles colliding in the vicinity of acceleration and event horizons of the Plebanski and Demianski class of black holes. We calculate the collision energy of uncharged particles in the center-of-mass frame that are freely falling along the equatorial plane of a charged accelerating and rotating black hole with an NUT parameter. This energy turns out to be infinite in the non-extremal case, while in the extremal case, it becomes infinitely large near the event horizon only if the particle has the critical angular momentum. We conclude that the center-of-mass energy depends on the rotation and the NUT parameter.

  6. Black Hole Radiation and Volume Statistical Entropy

    E-Print Network [OSTI]

    Mario Rabinowitz


    The simplest possible equation for Hawking radiation, and other black hole radiated power is derived in terms of black hole density. Black hole density also leads to the simplest possible model of a gas of elementary constituents confined inside a gravitational bottle of Schwarzchild radius at tremendous pressure, which yields identically the same functional dependence as the traditional black hole entropy. Variations of Sbh can be obtained which depend on the occupancy of phase space cells. A relation is derived between the constituent momenta and the black hole radius which is similar to the Compton wavelength relation.

  7. Overview of the ARGOS X-ray framing camera for Laser MegaJoule

    SciTech Connect (OSTI)

    Trosseille, C., E-mail:; Aubert, D.; Auger, L.; Bazzoli, S.; Brunel, P.; Burillo, M.; Chollet, C.; Jasmin, S.; Maruenda, P.; Moreau, I.; Oudot, G.; Raimbourg, J.; Soullié, G.; Stemmler, P.; Zuber, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Beck, T. [CEA, DEN, CADARACHE, F-13108 St Paul lez Durance (France); Gazave, J. [CEA, DAM, CESTA, F-33116 Le Barp (France)


    Commissariat à l’Énergie Atomique et aux Énergies Alternatives has developed the ARGOS X-ray framing camera to perform two-dimensional, high-timing resolution imaging of an imploding target on the French high-power laser facility Laser MegaJoule. The main features of this camera are: a microchannel plate gated X-ray detector, a spring-loaded CCD camera that maintains proximity focus in any orientation, and electronics packages that provide remotely-selectable high-voltages to modify the exposure-time of the camera. These components are integrated into an “air-box” that protects them from the harsh environmental conditions. A miniaturized X-ray generator is also part of the device for in situ self-testing purposes.

  8. Wavelet Bi-frames with few Generators from Multivariate Refinable Functions

    E-Print Network [OSTI]

    Ehler, Martin

    Wavelet Bi-frames with few Generators from Multivariate Refinable Functions Martin Ehler Bin Han compactly supported wavelet bi-frames with few generators from almost any pair of compactly sup- ported multivariate refinable functions. In our examples, we focus on wavelet bi-frames whose primal and dual wavelets

  9. MRA Based Wavelet Frames and Applications: Image Segmentation and Surface Reconstruction

    E-Print Network [OSTI]

    Zakharov, Vladimir

    MRA Based Wavelet Frames and Applications: Image Segmentation and Surface Reconstruction Bin Dong1 Kent Ridge Road, Singapore, 119076 ABSTRACT Theory of wavelet frames and their applications to image restoration problems have been extensively studied for the past two decades. The success of wavelet frames


    E-Print Network [OSTI]

    Johnson, Brody Dylan

    ORTHOGONAL WAVELET FRAMES AND VECTOR-VALUED WAVELET TRANSFORMS GHANSHYAM BHATT, BRODY DYLAN JOHNSON for the construction of orthogonal MRA wavelet frames in L2 (R) from a suitable scaling function. These constructions banks, the orthogonal wavelet frames give rise to a vector-valued discrete wavelet transform (VDWT

  11. Cooling air recycling for gas turbine transition duct end frame and related method

    DOE Patents [OSTI]

    Cromer, Robert Harold (Johnstown, NY); Bechtel, William Theodore (Scotia, NY); Sutcu, Maz (Niskayuna, NY)


    A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

  12. Optimization in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman Black Holes

    E-Print Network [OSTI]

    Auttakit Chatrabhuti; Khem Upathambhakul


    In this short report, we investigate the mutual information hidden in the Parikh-Wilczek tunneling model of Hawking radiation for Kerr-Newman black holes. By assuming the radiation as an optimization process, we discuss its effect on time evolution of rotating (charged and uncharged) black holes. For uncharged rotating black holes evaporating under the maximum mutual information optimization, their scale invariant rotation parameter $a_*=a/M$ is almost constant at the early stage but rapidly increase at the very last stage of the evaluation process. The value of rotation parameter at the final state of evaporation depends on the initial condition of the black hole. We also found that the presence of electric charge can cause the black holes lose their angular momentum more rapidly than they lose mass. The charged-rotating black holes asymptotically approach a state which is described by $a_*= 0$ and $Q/M = 1$.

  13. A Moving Frame Algorithm for High Mach Number Hydrodynamics

    E-Print Network [OSTI]

    Hy Trac; Ue-Li Pen


    We present a new approach to Eulerian computational fluid dynamics that is designed to work at high Mach numbers encountered in astrophysical hydrodynamic simulations. The Eulerian fluid conservation equations are solved in an adaptive frame moving with the fluid where Mach numbers are minimized. The moving frame approach uses a velocity decomposition technique to define local kinetic variables while storing the bulk kinetic components in a smoothed background velocity field that is associated with the grid velocity. Gravitationally induced accelerations are added to the grid, thereby minimizing the spurious heating problem encountered in cold gas flows. Separately tracking local and bulk flow components allows thermodynamic variables to be accurately calculated in both subsonic and supersonic regions. A main feature of the algorithm, that is not possible in previous Eulerian implementations, is the ability to resolve shocks and prevent spurious heating where both the preshock and postshock Mach numbers are high. The hybrid algorithm combines the high resolution shock capturing ability of the second-order accurate Eulerian TVD scheme with a low-diffusion Lagrangian advection scheme. We have implemented a cosmological code where the hydrodynamic evolution of the baryons is captured using the moving frame algorithm while the gravitational evolution of the collisionless dark matter is tracked using a particle-mesh N-body algorithm. The MACH code is highly suited for simulating the evolution of the IGM where accurate thermodynamic evolution is needed for studies of the Lyman alpha forest, the Sunyaev-Zeldovich effect, and the X-ray background. Hydrodynamic and cosmological tests are described and results presented. The current code is fast, memory-friendly, and parallelized for shared-memory machines.

  14. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B. [Centro Multidisciplinar de Astrofisica, CENTRA, Departamento de Fisica, Instituto Superior Tecnico-IST, Universidade Tecnica de Lisboa-UTL, Avenida Rovisco Pais 1, 1049-001 Lisboa (Portugal); Astronomical Institute of Kharkov, V. N. Karazin National University, 35 Sumskaya Street, Kharkov, 61022 (Ukraine)


    Black hole mimickers are possible alternatives to black holes; they would look observationally almost like black holes but would have no horizon. The properties in the near-horizon region where gravity is strong can be quite different for both types of objects, but at infinity it could be difficult to discern black holes from their mimickers. To disentangle this possible confusion, we examine the near-horizon properties, and their connection with far away asymptotic properties, of some candidates to black mimickers. We study spherically symmetric uncharged or charged but nonextremal objects, as well as spherically symmetric charged extremal objects. Within the uncharged or charged but nonextremal black hole mimickers, we study nonextremal {epsilon}-wormholes on the threshold of the formation of an event horizon, of which a subclass are called black foils, and gravastars. Within the charged extremal black hole mimickers we study extremal {epsilon}-wormholes on the threshold of the formation of an event horizon, quasi-black holes, and wormholes on the basis of quasi-black holes from Bonnor stars. We elucidate whether or not the objects belonging to these two classes remain regular in the near-horizon limit. The requirement of full regularity, i.e., finite curvature and absence of naked behavior, up to an arbitrary neighborhood of the gravitational radius of the object enables one to rule out potential mimickers in most of the cases. A list ranking the best black hole mimickers up to the worst, both nonextremal and extremal, is as follows: wormholes on the basis of extremal black holes or on the basis of quasi-black holes, quasi-black holes, wormholes on the basis of nonextremal black holes (black foils), and gravastars. Since in observational astrophysics it is difficult to find extremal configurations (the best mimickers in the ranking), whereas nonextremal configurations are really bad mimickers, the task of distinguishing black holes from their mimickers seems to be less difficult than one could think of it.

  15. Black Hole Evaporation as a Nonequilibrium Process

    E-Print Network [OSTI]

    Hiromi Saida


    When a black hole evaporates, there arises a net energy flow from the black hole into its outside environment due to the Hawking radiation and the energy accretion onto black hole. Exactly speaking, due to the net energy flow, the black hole evaporation is a nonequilibrium process. To study details of evaporation process, nonequilibrium effects of the net energy flow should be taken into account. In this article we simplify the situation so that the Hawking radiation consists of non-self-interacting massless matter fields and also the energy accretion onto the black hole consists of the same fields. Then we find that the nonequilibrium nature of black hole evaporation is described by a nonequilibrium state of that field, and we formulate nonequilibrium thermodynamics of non-self-interacting massless fields. By applying it to black hole evaporation, followings are shown: (1) Nonequilibrium effects of the energy flow tends to accelerate the black hole evaporation, and, consequently, a specific nonequilibrium phenomenon of semi-classical black hole evaporation is suggested. Furthermore a suggestion about the end state of quantum size black hole evaporation is proposed in the context of information loss paradox. (2) Negative heat capacity of black hole is the physical essence of the generalized second law of black hole thermodynamics, and self-entropy production inside the matter around black hole is not necessary to ensure the generalized second law. Furthermore a lower bound for total entropy at the end of black hole evaporation is given. A relation of the lower bound with the so-called covariant entropy bound conjecture is interesting but left as an open issue.

  16. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'. WilliamEnergyMolecular StructureMolecular-Frame

  17. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'. WilliamEnergyMolecularMolecular-Frame Angular

  18. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighandSWPA / SPRA /Ml'. WilliamEnergyMolecularMolecular-Frame

  19. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your1 SECTION A.ModelAlyssaReceptorinCenterMolecular-Frame

  20. Quantum thermodynamics with missing reference frames: Decompositions of free energy into non-increasing components

    E-Print Network [OSTI]

    Dominik Janzing


    If an absolute reference frame with respect to time, position, or orientation is missing one can only implement quantum operations which are covariant with respect to the corresponding unitary symmetry group G. Extending observations of Vaccaro et al., I argue that the free energy of a quantum system with G-invariant Hamiltonian then splits up into the Holevo information of the orbit of the state under the action of G and the free energy of its orbit average. These two kinds of free energy cannot be converted into each other. The first component is subadditive and the second superadditive; in the limit of infinitely many copies only the usual free energy matters. Refined splittings of free energy into more than two independent (non-increasing) terms can be defined by averaging over probability measures on G that differ from the Haar measure. Even in the presence of a reference frame, these results provide lower bounds on the amount of free energy that is lost after applying a covariant channel. If the channel properly decreases one of these quantities, it decreases the free energy necessarily at least by the same amount, since it is unable to convert the different forms of free energies into each other.

  1. BSW process of the slowly evaporating charged black hole

    E-Print Network [OSTI]

    Liancheng Wang; Feng He; Xiangyun Fu


    In this paper, we study the BSW process of the slowly evaporating charged black hole. It can be found that the BSW process will also arise near black hole horizon when the evaporation of charged black hole is very slow. But now the background black hole does not have to be an extremal black hole, and it will be approximately an extremal black hole unless it is nearly a huge stationary black hole.

  2. A study of problems in survey technique encountered when using a multiple frame survey

    E-Print Network [OSTI]

    Conner, James Richard


    of the multiple trame sampling technique, one is faced with the problem of finding suitable frames to combine with it. Sin~e many incomplete iist frame: are readily a. . eilable, and mail sampling of lists s usually less expensive than dire t interviews.... Identification of units sampled in both frames. 5. Response rates, i, e. , effects of low response to the mail survey if applicable. 6. Estimates of farm characteristics from the joint use of two frames and comparison with area frame estimates. Description...

  3. Black hole mergers: do gas discs lead to spin alignment?

    E-Print Network [OSTI]

    Giuseppe Lodato; Davide Gerosa


    In this Letter we revisit arguments suggesting that the Bardeen-Petterson effect can coalign the spins of a central supermassive black hole binary accreting from a circumbinary (or circumnuclear) gas disc. We improve on previous estimates by adding the dependence on system parameters, and noting that the nonlinear nature of warp propagation in a thin viscous disc affects alignment. This reduces the disc's ability to communicate the warp, and can severely reduce the effectiveness of disc-assisted spin alignment. We test our predictions with a Monte Carlo realization of random misalignments and accretion rates and we find that the outcome depends strongly on the spin magnitude. We estimate a generous upper limit to the probability of alignment by making assumptions which favour it throughout. Even with these assumptions, about 40% of black holes with $a \\gtrsim 0.5$ do not have time to align with the disc. If the residual misalignment is not small and it is maintained down to the final coalescence phase this can give a powerful recoil velocity to the merged hole. Highly spinning black holes are thus more likely of being subject to strong recoils, the occurrence of which is currently debated.

  4. Do spinors give rise to a frame-dragging effect?

    SciTech Connect (OSTI)

    Randono, Andrew [Institute for Gravitation and the Cosmos, Pennsylvania State University, 104 Davey Lab, University Park, Pennsylvania 16802 (United States) and Perimeter Institute for Theoretical Physics, 31 Caroline Street North Waterloo, ON N2L 2Y5 (Canada)


    We investigate the effect of the intrinsic spin of a fundamental spinor field on the surrounding spacetime geometry. We show that despite the lack of a rotating stress-energy source (and despite claims to the contrary) the intrinsic spin of a spin-half fermion gives rise to a frame-dragging effect analogous to that of orbital angular momentum, even in Einstein-Hilbert gravity where torsion is constrained to be zero. This resolves a paradox regarding the counter-force needed to restore Newton's third law in the well-known spin-orbit interaction. In addition, the frame-dragging effect gives rise to a long-range gravitationally mediated spin-spin dipole interaction coupling the internal spins of two sources. We argue that despite the weakness of the interaction, the spin-spin interaction will dominate over the ordinary inverse square Newtonian interaction in any process of sufficiently high energy for quantum field theoretical effects to be non-negligible.

  5. Down hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, Harry C. (Albuquerque, NM); Hills, Richard G. (Las Cruces, NM); Striker, Richard P. (Albuquerque, NM)


    A down hole periodic seismic generator system for transmitting variable frequency, predominantly shear-wave vibration into earth strata surrounding a borehole. The system comprises a unitary housing operably connected to a well head by support and electrical cabling and contains clamping apparatus for selectively clamping the housing to the walls of the borehole. The system further comprises a variable speed pneumatic oscillator and a self-contained pneumatic reservoir for producing a frequency-swept seismic output over a discrete frequency range.

  6. Charged spinning black holes as particle accelerators

    SciTech Connect (OSTI)

    Wei Shaowen; Liu Yuxiao; Guo Heng; Fu Chune [Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000 (China)


    It has recently been pointed out that the spinning Kerr black hole with maximal spin could act as a particle collider with arbitrarily high center-of-mass energy. In this paper, we will extend the result to the charged spinning black hole, the Kerr-Newman black hole. The center-of-mass energy of collision for two uncharged particles falling freely from rest at infinity depends not only on the spin a but also on the charge Q of the black hole. We find that an unlimited center-of-mass energy can be approached with the conditions: (1) the collision takes place at the horizon of an extremal black hole; (2) one of the colliding particles has critical angular momentum; (3) the spin a of the extremal black hole satisfies (1/{radical}(3)){<=}(a/M){<=}1, where M is the mass of the Kerr-Newman black hole. The third condition implies that to obtain an arbitrarily high energy, the extremal Kerr-Newman black hole must have a large value of spin, which is a significant difference between the Kerr and Kerr-Newman black holes. Furthermore, we also show that, for a near-extremal black hole, there always exists a finite upper bound for center-of-mass energy, which decreases with the increase of the charge Q.

  7. Submicron patterned metal hole etching

    DOE Patents [OSTI]

    McCarthy, Anthony M. (Menlo Park, CA); Contolini, Robert J. (Lake Oswego, OR); Liberman, Vladimir (Needham, MA); Morse, Jeffrey (Martinez, CA)


    A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.

  8. Quantum Geometry and Black Holes

    E-Print Network [OSTI]

    G., J Fernando Barbero


    We present an overall picture of the advances in the description of black hole physics from the perspective of loop quantum gravity. After an introduction that discusses the main conceptual issues we present some details about the classical and quantum geometry of isolated horizons and their quantum geometry and then use this scheme to give a natural definition of the entropy of black holes. The entropy computations can be neatly expressed in the form of combinatorial problems solvable with the help of methods based on number theory and the use of generating functions. The recovery of the Bekenstein-Hawking law and corrections to it is explained in some detail. After this, due attention is paid to the discussion of semiclassical issues. An important point in this respect is the proper interpretation of the horizon area as the energy that should appear in the statistical-mechanical treatment of the black hole model presented here. The chapter ends with a comparison between the microscopic and semiclassical app...

  9. Entangled valence electron-hole dynamics revealed by stimulated attosecond x-ray Raman scattering

    SciTech Connect (OSTI)

    Healion, Daniel; Zhang, Yu; Biggs, Jason D.; Govind, Niranjan; Mukamel, Shaul


    We show that broadband x-ray pulses can create wavepackets of valence electrons and holes localized in the vicinity of a selected atom (nitrogen, oxygen or sulfur in cysteine) by resonant stimulated Raman scattering. The subsequent dynamics reveals highly correlated motions of entangled electrons and hole quasiparticles. This information goes beyond the time-dependent total charge density derived from x-ray diffraction.

  10. Chemical aspects of cylinder corrosion and a scenario for hole development

    SciTech Connect (OSTI)

    Barber, E.J. [Martin Marietta Energy Systems, Oak Ridge, TN (United States)


    In June 1990, two cylinders in the depleted UF{sub 6} cylinder storage yards at Portsmouth were discovered to have holes in their walls at the valve-end stiffening ring at a point below the level of the gas-solid interface of the UF{sub 6}. The cylinder with the larger hole, which extended under the stiffening ring, was stacked in a top row 13 years ago. The cylinder with the smaller hole had been stacked in a bottom row 4 years ago. The lifting lugs of the adjacent cylinders pointed directly at the holes. A Cylinder Investigating Committee was appointed to determine the cause or causes of the holes and to assess the implications of these findings. This report contains a listing of the chemically related facts established by the Investigating Committee with the cooperation of the Operations and Technical Support Divisions at the Portsmouth Gaseous Diffusion Plant, the scenario developed to explain these findings and some implications of this scenario. In summary, the interrelated reactions of water, solid UF{sub 6} and iron presented by R. L. Ritter are used to develop a scenario which explains the observations and deductions made during the investigation. The chemical processes are intimately related to the course of the last three of the four stages of hole development. A simple model is proposed which permits semiquantitative prediction of such information as the HF loss rates as a function of time, the rate of hole enlargement, the time to hydrolyze a cylinder of UF{sub 6} and the approximate size of the hole. The scenario suggests that the environmental consequences associated with a developing hole in a depleted UF{sub 6} cylinder are minimal for the first several years but will become significant if too many years pass before detection. The overall environmental picture is presented in more detail elsewhere.

  11. Soil-structure Interaction in the Seismic Response of Coupled Wall-frame Structures on Pile Foundations

    SciTech Connect (OSTI)

    Carbonari, S. [Dept of Architecture, Constructions, Structures, Universita Politecnica delle Marche (Italy); Dezi, F. [Dept of Materials, Environment Engineering, Physics, Universita Politecnica delle Marche (Italy); Leoni, G. [Dept ProCAm, Universita di Camerino, Ascoli Piceno (Italy)


    This paper presents a study on the seismic response of coupled wall-frame structures founded on piles. A complete soil-structure interaction analysis is carried out with reference to a case study. Three different soils and seven real accelerograms are considered. Local site response analyses are performed in order to evaluate the incoming free-field motion at different depths and the ground motion amplifications. A numerical model, accounting for the pile-soil-pile interaction and for material and radiation damping, is used to evaluate the impedance matrix and the foundation input motion. The domain decomposition technique is adopted to perform time-domain seismic analyses introducing Lumped Parameter Models to take into account the impedance of the soil-structure system. Applications show that the rocking phenomena affect the behaviour of the structure by changing the base shear distribution within the wall and the frame and by increasing the structural displacements.

  12. Modified locus equations categorize stop place in a perceptually realistic time frame

    E-Print Network [OSTI]

    Rhone, Ariane E.; Jongman, Allard


    invariance for stop place categorization,” J. Acoust. Soc. Am. 90, 1309–1325 (1991). 7H. M. Sussman, D. Fruchter, J. Hilbert, and J. Sirosh, “Linear correlates in the speech signal: The orderly output constraint,” Behav. Brain Sci. 21, 241–259 (1998). 8B...

  13. AAC R17-1-102 Licensing Time Frames | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving You are now leaving You are beingZealand Jump to:Ezfeedflag JumpID-fTriWildcat 1 WindtheEnergySulfonate as aAAB Asia Alliance

  14. Black holes are almost optimal quantum cloners

    E-Print Network [OSTI]

    C. Adami; G. Ver Steeg


    If black holes were able to clone quantum states, a number of paradoxes in black hole physics would disappear. However, the linearity of quantum mechanics forbids exact cloning of quantum states. Here we show that black holes indeed clone incoming quantum states with a fidelity that depends on the black hole's absorption coefficient, without violating the no-cloning theorem because the clones are only approximate. Perfectly reflecting black holes are optimal universal "quantum cloning machines" and operate on the principle of stimulated emission, exactly as their quantum optical counterparts. In the limit of perfect absorption, the fidelity of clones is equal to what can be obtained via quantum state estimation methods. But for any absorption probability less than one, the cloning fidelity is nearly optimal as long as $\\omega/T\\geq10$, a common parameter for modest-sized black holes.

  15. "Meissner effect" and Blandford-Znajek mechanism in conductive black hole magnetospheres

    E-Print Network [OSTI]

    S. S. Komissarov; J. C. McKinney


    The expulsion of axisymmetric magnetic field from the event horizons of rapidly rotating black holes has been seen as an astrophysically important effect that may significantly reduce or even nullify the efficiency of the Blandford-Znajek mechanism of powering the relativistic jets in Active Galactic Nuclei and Gamma Ray Bursts. However, this Meissner-like effect is seen in vacuum solutions of black hole electrodynamics whereas the Blandford-Znajek mechanism is concerned with plasma-filled magnetospheres. In this paper we argue that conductivity dramatically changes the properties of axisymmetric electromagnetic solutions -- even for a maximally rotating Kerr black hole the magnetic field is pulled inside the event horizon. Moreover, the conditions resulting in outgoing Poynting flux in the Blandford-Znajek mechanism exist not on the event horizon but everywhere within the black hole ergosphere. Thus, the Meissner effect is unlikely to be of interest in astrophysics of black holes, at least not in the way this has been suggested so far. These conclusions are supported by the results of time-dependent numerical simulations with three different computer codes. The test problems involve black holes with the rotation parameter ranging from $a=0.999$ to $a=1$. The pure electrodynamic simulations deal with the structure of conductive magnetospheres of black holes placed in a uniform-at-infinity magnetic field (Wald's problem) and the magnetohydrodynamic simulations are used to study the magnetospheres arising in the problem of disk accretion.

  16. Supermassive Black Hole Growth and Merger Rates from Cosmological N-body Simulations

    E-Print Network [OSTI]

    Miroslav Micic; Kelly Holley-Bockelmann; Steinn Sigurdsson; Tom Abel


    Understanding how seed black holes grow into intermediate and supermassive black holes (IMBHs and SMBHs, respectively) has important implications for the duty-cycle of active galactic nuclei (AGN), galaxy evolution, and gravitational wave astronomy. Most studies of the cosmological growth and merger history of black holes have used semianalytic models and have concentrated on SMBH growth in luminous galaxies. Using high resolution cosmological N-body simulations, we track the assembly of black holes over a large range of final masses -- from seed black holes to SMBHs -- over widely varying dynamical histories. We used the dynamics of dark matter halos to track the evolution of seed black holes in three different gas accretion scenarios. We have found that growth of Sagittarius A* - size SMBH reaches its maximum mass M_{SMBH}~10^6Msun at z~6 through early gaseous accretion episodes, after which it stays at near constant mass. At the same redshift, the duty-cycle of the host AGN ends, hence redshift z=6 marks the transition from an AGN to a starburst galaxy which eventually becomes the Milky Way. By tracking black hole growth as a function of time and mass, we estimate that the IMBH merger rate reaches a maximum of R_{max}=55 yr^-1 at z=11. From IMBH merger rates we calculate N_{ULX}=7 per Milky Way type galaxy per redshift in redshift range 2

  17. Impacts of generalized uncertainty principle on black hole thermodynamics and Salecker-Wigner inequalities

    SciTech Connect (OSTI)

    Tawfik, A., E-mail: [Egyptian Center for Theoretical Physics (ECTP), MTI University, 11571 Cairo (Egypt)


    We investigate the impacts of Generalized Uncertainty Principle (GUP) proposed by some approaches to quantum gravity such as String Theory and Doubly Special Relativity on black hole thermodynamics and Salecker-Wigner inequalities. Utilizing Heisenberg uncertainty principle, the Hawking temperature, Bekenstein entropy, specific heat, emission rate and decay time are calculated. As the evaporation entirely eats up the black hole mass, the specific heat vanishes and the temperature approaches infinity with an infinite radiation rate. It is found that the GUP approach prevents the black hole from the entire evaporation. It implies the existence of remnants at which the specific heat vanishes. The same role is played by the Heisenberg uncertainty principle in constructing the hydrogen atom. We discuss how the linear GUP approach solves the entire-evaporation-problem. Furthermore, the black hole lifetime can be estimated using another approach; the Salecker-Wigner inequalities. Assuming that the quantum position uncertainty is limited to the minimum wavelength of measuring signal, Wigner second inequality can be obtained. If the spread of quantum clock is limited to some minimum value, then the modified black hole lifetime can be deduced. Based on linear GUP approach, the resulting lifetime difference depends on black hole relative mass and the difference between black hole mass with and without GUP is not negligible.

  18. Development of a dual MCP framing camera for high energy x-rays

    SciTech Connect (OSTI)

    Izumi, N., E-mail:; Hall, G. N.; Carpenter, A. C.; Allen, F. V.; Cruz, J. G.; Felker, B.; Hargrove, D.; Holder, J.; Lumbard, A.; Montesanti, R.; Palmer, N. E.; Piston, K.; Stone, G.; Thao, M.; Vern, R.; Zacharias, R.; Landen, O. L.; Tommasini, R.; Bradley, D. K.; Bell, P. M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others


    Recently developed diagnostic techniques at LLNL require recording backlit images of extremely dense imploded plasmas using hard x-rays, and demand the detector to be sensitive to photons with energies higher than 50 keV [R. Tommasini et al., Phys. Phys. Plasmas 18, 056309 (2011); G. N. Hall et al., “AXIS: An instrument for imaging Compton radiographs using ARC on the NIF,” Rev. Sci. Instrum. (these proceedings)]. To increase the sensitivity in the high energy region, we propose to use a combination of two MCPs. The first MCP is operated in a low gain regime and works as a thick photocathode, and the second MCP works as a high gain electron multiplier. We tested the concept of this dual MCP configuration and succeeded in obtaining a detective quantum efficiency of 4.5% for 59 keV x-rays, 3 times larger than with a single plate of the thickness typically used in NIF framing cameras.

  19. Remarks on Renormalization of Black Hole Entropy

    E-Print Network [OSTI]

    Sang Pyo Kim; Sung Ku Kim; Kwang-Sup Soh; Jae Hyung Yee


    We elaborate the renormalization process of entropy of a nonextremal and an extremal Reissner-Nordstr\\"{o}m black hole by using the Pauli-Villars regularization method, in which the regulator fields obey either the Bose-Einstein or Fermi-Dirac distribution depending on their spin-statistics. The black hole entropy involves only two renormalization constants. We also discuss the entropy and temperature of the extremal black hole.

  20. Hole cleaning requirements with seabed returns

    E-Print Network [OSTI]

    Nordt, David Paul


    of different non-Newtonian fluids 56 INTRODUCTION A drilling fluid is used for removing cuttings from the hole, controlling subsurface pressures, preventing caving-in of the formations, suspension of cuttings, weighting materials, and many other uses... of the hole. The drilling problems related to hole cleaning can occur at low as well as high annular velocities. Cuttings can travel no faster than the fluid in which they are transported; however, they can travel more slowly. Their fall (slip) rate...

  1. Probing the Constituent Structure of Black Holes

    E-Print Network [OSTI]

    Lukas Gruending; Stefan Hofmann; Sophia Müller; Tehseen Rug


    We calculate the cross section for scattering processes between graviton emitters on the near side of a Schwarzschild surface and absorbers on its far side, that is black hole constituents. We show that these scatterings allow to directly extract structural observables such as the momentum distribution of black hole constituents. For this we employ a quantum bound state description originally developed in quantum chromodynamics and recently applied to general relativity that allows to consider black holes in a relativistic Hartree like framework.

  2. Black hole initial data without elliptic equations

    E-Print Network [OSTI]

    István Rácz; Jeffrey Winicour


    We explore whether a new method to solve the constraints of Einstein's equations, which does not involve elliptic equations, can be applied to provide initial data for black holes. We show that this method can be successfully applied to a nonlinear perturbation of a Schwarzschild black hole by establishing the well-posedness of the resulting constraint problem. We discuss its possible generalization to the boosted, spinning multiple black hole problem.

  3. Black holes with massive graviton hair

    E-Print Network [OSTI]

    Richard Brito; Vitor Cardoso; Paolo Pani


    No-hair theorems exclude the existence of nontrivial scalar and massive vector hair outside four-dimensional, static, asymptotically flat black-hole spacetimes. We show, by explicitly building nonlinear solutions, that black holes can support massive graviton hair in theories of massive gravity. These hairy solutions are, most likely, the generic end state of the recently discovered monopole instability of Schwarzschild black holes in massive graviton theories.

  4. Black Holes in Galaxy Mergers: Evolution of Quasars

    E-Print Network [OSTI]

    Philip F. Hopkins; Lars Hernquist; Thomas J. Cox; Tiziana Di Matteo; Paul Martini; Brant Robertson; Volker Springel


    Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth of supermassive black holes in galaxies. Nuclear inflow of gas attending a galaxy collision triggers a starburst and feeds black hole growth, but for most of the duration of the starburst, the black hole is heavily obscured by surrounding gas and dust which limits the visibility of the quasar, especially at optical and UV wavelengths. Eventually, feedback energy from accretion heats the gas and expels it in a powerful wind, leaving a 'dead quasar'. Between buried and dead phases there is a window during which the galaxy would be seen as a luminous quasar. Because the black hole mass, radiative output, and distribution of obscuring gas and dust all evolve strongly with time, the duration of this phase of observable quasar activity depends on both the waveband and imposed luminosity threshold. We determine the observed and intrinsic lifetimes as a function of luminosity and frequency, and calculate observable lifetimes ~10 Myr for bright quasars in the optical B-band, in good agreement with empirical estimates and much smaller than the black hole growth timescales ~100 Myr, naturally producing a substantial population of 'buried' quasars. However, observed and intrinsic energy outputs converge in the IR and hard X-ray bands as attenuation becomes weaker and chances of observation greatly increase. We obtain the distribution of column densities along sightlines in which the quasar is seen above a given luminosity, and find that our result agrees remarkably well with observed estimates of the column density distribution from the SDSS for appropriate luminosity thresholds. (Abridged)

  5. Thermoelectric DC conductivities from black hole horizons

    E-Print Network [OSTI]

    Aristomenis Donos; Jerome P. Gauntlett


    An analytic expression for the DC electrical conductivity in terms of black hole horizon data was recently obtained for a class of holographic black holes exhibiting momentum dissipation. We generalise this result to obtain analogous expressions for the DC thermoelectric and thermal conductivities. We illustrate our results using some holographic Q-lattice black holes as well as for some black holes with linear massless axions, in both $D=4$ and $D=5$ bulk spacetime dimensions, which include both spatially isotropic and anisotropic examples. We show that some recently constructed ground states of holographic Q-lattices, which can be either electrically insulating or metallic, are all thermal insulators.

  6. Mineral Test Hole Regulatory Act (Tennessee)

    Broader source: [DOE]

    The Mineral Hole Regulatory Act is applicable to any person (individual, corporation, company, association, joint venture, partnership, receiver, trustee, guardian, executor, administrator,...

  7. Black Holes: from Speculations to Observations

    E-Print Network [OSTI]

    Thomas W. Baumgarte


    This paper provides a brief review of the history of our understanding and knowledge of black holes. Starting with early speculations on ``dark stars'' I discuss the Schwarzschild "black hole" solution to Einstein's field equations and the development of its interpretation from "physically meaningless" to describing the perhaps most exotic and yet "most perfect" macroscopic object in the universe. I describe different astrophysical black hole populations and discuss some of their observational evidence. Finally I close by speculating about future observations of black holes with the new generation of gravitational wave detectors.

  8. Lower Dimensional Black Holes: Inside and Out

    E-Print Network [OSTI]

    R. B. Mann


    I survey the physics of black holes in two and three spacetime dimensions, with special attention given to an understanding of their exterior and interior properties.

  9. Approximate initial data for binary black holes

    E-Print Network [OSTI]

    Kenneth A. Dennison; Thomas W. Baumgarte; Harald P. Pfeiffer


    We construct approximate analytical solutions to the constraint equations of general relativity for binary black holes of arbitrary mass ratio in quasicircular orbit. We adopt the puncture method to solve the constraint equations in the transverse-traceless decomposition and consider perturbations of Schwarzschild black holes caused by boosts and the presence of a binary companion. A superposition of these two perturbations then yields approximate, but fully analytic binary black hole initial data that are accurate to first order in the inverse of the binary separation and the square of the black holes' momenta.

  10. A new spin on black hole hair

    E-Print Network [OSTI]

    Herdeiro, Carlos A R


    We show that scalar hair can be added to rotating, vacuum black holes of general relativity. These hairy black holes (HBHs) clarify a lingering question concerning gravitational solitons: if a black hole can be added at the centre of a boson star, as it typically can for other solitons. We argue that it can, but only if it is spinning. The existence of such HBHs is related to the Kerr superradiant instability triggered by a massive scalar field. This connection leads to the following conjecture: a (hairless) black hole which is afflicted by the superradiant instability of a given field must allow hairy generalizations with that field.

  11. Lunar Laser Ranging, Gravitomagnetism and Frame-Dragging

    E-Print Network [OSTI]

    Ignazio Ciufolini


    During the past century Einstein's theory of General Relativity gave rise to an experimental triumph, however, there are still aspects of this theory to be measured or more accurately tested. One of the main challenges in experimental gravitation, together with the direct detection of gravitational waves, is today the accurate measurement of the gravitomagnetic field generated by the angular momentum of a body. Here, after a description of frame-dragging and gravitomagnetism and of the main experiments to detect these relativistic phenomena, we show that the fundamental tests of General Relativity performed by Lunar Laser Ranging do not, however, include a measurement of the intrinsic gravitomagnetic field generated by the angular momentum of a body.

  12. Weitzenb\\"ock's Torsion, Fermi Coordinates and Adapted Frames

    E-Print Network [OSTI]

    Bini, Donato


    We study Weitzenb\\"ock's torsion and discuss its properties. Specifically, we calculate the measured components of Weitzenb\\"ock's torsion tensor for a frame field adapted to static observers in a Fermi normal coordinate system that we establish along the world line of an arbitrary accelerated observer in general relativity. A similar calculation is carried out in the standard Schwarzschild-like coordinates for static observers in the exterior Kerr spacetime; we then compare our results with the corresponding curvature components. Our work supports the contention that in the extended general relativistic framework involving both the Levi-Civita and Weitzenb\\"ock connections, curvature and torsion provide complementary representations of the gravitational field.

  13. Gauge Gravity and Space-Time

    E-Print Network [OSTI]

    Ning Wu


    When we discuss problems on gravity, we can not avoid some fundamental physical problems, such as space-time, inertia, and inertial reference frame. The goal of this paper is to discuss the logic system of gravity theory and the problems of space-time, inertia, and inertial reference frame. The goal of this paper is to set up the theory on space-time in gauge theory of gravity. Based on this theory, it is possible for human kind to manipulate physical space-time on earth, and produce a machine which can physically prolong human's lifetime.

  14. Rotating embedded black holes: Entropy and Hawking's radiation

    E-Print Network [OSTI]

    Ng Ibohal


    In this paper we derive a class of rotating embedded black holes. Then we study Hawking's radiation effects on these embedded black holes. The surface gravity, entropy and angular velocity are given for each of these black holes.

  15. Construction and physical properties of Kerr black holes with scalar hair

    E-Print Network [OSTI]

    Herdeiro, Carlos


    Kerr black holes with scalar hair are solutions of the Einstein-Klein-Gordon field equations describing regular (on and outside an event horizon), asymptotically flat black holes with scalar hair (arXiv:1403.2757). These black holes interpolate continuously between the Kerr solution and rotating boson stars in D=4 spacetime dimensions. Here we provide details on their construction, discussing properties of the ansatz, the field equations, the boundary conditions and the numerical strategy. Then, we present an overview of the parameter space of the solutions, and describe in detail the space-time structure of the black holes exterior geometry and of the scalar field for a sample of reference solutions. Phenomenological properties of potential astrophysical interest are also discussed, and the stability properties and possible generalizations are commented on. As supplementary material to this paper we make available numerical data files for the sample of reference solutions discussed, for public use.

  16. The scattering matrix approach for the quantum black hole, an overview

    E-Print Network [OSTI]

    G. 't Hooft


    If one assumes the validity of conventional quantum field theory in the vicinity of the horizon of a black hole, one does not find a quantum mechanical description of the entire black hole that even remotely resembles that of conventional forms of matter; in contrast with matter made out of ordinary particles one finds that, even if embedded in a finite volume, a black hole would be predicted to have a strictly continuous spectrum. Dissatisfied with such a result, which indeed hinges on assumptions concerning the horizon that may well be wrong, various investigators have now tried to formulate alternative approaches to the problem of ``quantizing" the black hole. We here review the approach based on the assumption of quantum mechanical purity and unitarity as a starting point, as has been advocated by the present author for some time, concentrating on the physics of the states that should live on a black hole horizon. The approach is shown to be powerful in not only producing promising models for the quantum black hole, but also new insights concerning the dynamics of physical degrees of freedom in ordinary flat space-time.

  17. Black Holes at the LHC: Progress since 2002

    SciTech Connect (OSTI)

    Park, Seong Chan [FRDP, Department of Physics and Astronomy, Seoul National University, Seoul (Korea, Republic of)


    We review the recent noticeable progresses in black hole physics focusing on the up-coming super-collider, the LHC. We discuss the classical formation of black holes by particle collision, the greybody factors for higher dimensional rotating black holes, the deep implications of black hole physics to the 'energy-distance' relation, the security issues of the LHC associated with black hole formation and the newly developed Monte-Carlo generators for black hole events.

  18. Results from large scale ultimate strength tests of K-braced jacket frame structures

    SciTech Connect (OSTI)

    Bolt, H.M.


    Phase 2 of the JIP Frames Project included four large scale collapse tests of K-braced frames in which both gap and overlap K joints were the critical components. The results are presented in this paper. The local failure modes differed from typical isolated component tests, yet were representative of structural damage observed following Hurricane Andrew. The frame test results therefore provide important insight to the ultimate response of offshore jacket structures.

  19. Asymptotically flat black holes with scalar hair: a review

    E-Print Network [OSTI]

    Carlos A. R. Herdeiro; Eugen Radu


    We consider the status of black hole solutions with non-trivial scalar fields but no gauge fields, in four dimensional asymptotically flat space-times, reviewing both classical results and recent developments. We start by providing a simple illustration on the physical difference between black holes in electro-vacuum and scalar-vacuum. Next, we review no-scalar-hair theorems. In particular, we detail an influential theorem by Bekenstein and stress three key assumptions: 1) the type of scalar field equation; 2) the spacetime symmetry inheritance by the scalar field; 3) an energy condition. Then, we list regular (on and outside the horizon), asymptotically flat BH solutions with scalar hair, organizing them by the assumption which is violated in each case and distinguishing primary from secondary hair. We provide a table summary of the state of the art.

  20. Asymptotically flat black holes with scalar hair: a review

    E-Print Network [OSTI]

    Herdeiro, Carlos A R


    We consider the status of black hole solutions with non-trivial scalar fields but no gauge fields, in four dimensional asymptotically flat space-times, reviewing both classical results and recent developments. We start by providing a simple illustration on the physical difference between black holes in electro-vacuum and scalar-vacuum. Next, we review no-scalar-hair theorems. In particular, we detail an influential theorem by Bekenstein and stress three key assumptions: 1) the type of scalar field equation; 2) the spacetime symmetry inheritance by the scalar field; 3) an energy condition. Then, we list regular (on and outside the horizon), asymptotically flat BH solutions with scalar hair, organizing them by the assumption which is violated in each case and distinguishing primary from secondary hair. We provide a table summary of the state of the art.

  1. CP Violation and Baryogenesis in the Presence of Black Holes

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler


    In a recent paper[1] Kundu and one of the present authors showed that there were transient but observable CP violating effects in the decay of classical currents on the horizon of a black hole, if the Lagrangian of the Maxwell field contained a CP violating angle {\\theta}. In this paper we demonstrate that a similar effect can be seen in the quantum mechanics of QED: a non-trivial Berry phase in the QED wave function is produced by in-falling electric charges. We also investigate whether CP violation, of this or any other type, might be used to produce the baryon asymmetry of the universe, in models where primordial black hole decay contributes to the matter content of the present universe. This can happen both in a variety of hybrid inflation models, and in the Holographic Space-time (HST) model of inflation[2].

  2. Black Hole Fluctuations and Backreaction in Stochastic Gravity

    E-Print Network [OSTI]

    Sukanya Sinha; Alpan Raval; B. L. Hu


    We present a framework for analyzing black hole backreaction from the point of view of quantum open systems using influence functional formalism. We focus on the model of a black hole described by a radially perturbed quasi-static metric and Hawking radiation by a conformally coupled massless quantum scalar field. It is shown that the closed-time-path (CTP) effective action yields a non-local dissipation term as well as a stochastic noise term in the equation of motion, the Einstein-Langevin equation. Once the thermal Green's function in a Schwarzschild background becomes available to the required accuracy the strategy described here can be applied to obtain concrete results on backreaction. We also present an alternative derivation of the CTP effective action in terms of the Bogolyubov coefficients, thus making a connection with the interpretation of the noise term as measuring the difference in particle production in alternative histories.

  3. Thermodynamics and Spectroscopy of Schwarzschild black hole surrounded by Quintessence

    E-Print Network [OSTI]

    R Tharanath; V C Kuriakose


    The thermodynamic and spectroscopic behaviour of Schwarzschild black hole surrounded by quintessence are studied. We have derived the thermodynamic quantities and studied their behaviour for different values of quintessence parameter. We put the background space-time into the Kruskal-like coordinate to find the period with respect to Elucidean time. Also assuming that the adiabatic invariant obeys Bohr-Sommerfeld quantization rule, detailed study of area spectrum and entropy spectrum have been done for special cases of the quintessece state parameter. We find that the spectra are equally spaced.

  4. Some differences between Dirac's hole theory and quantum field theory

    E-Print Network [OSTI]

    Dan Solomon


    Diracs hole theory (HT) and quantum field theory (QFT) are generally considered to be equivalent to each other. However, it has been recently shown by several researchers that this is not necessarily the case. When the change in the vacuum energy was calculated for a time independent perturbation HT and QFT yielded different results. In this paper we extend this discussion to include a time dependent perturbation for which the exact solution to the Dirac equation is known. It will be shown that for this case, also, HT and QFT yield different results. In addition, there will be some discussion of the problem of anomalies in QFT.

  5. Finite difference schemes for second order systems describing black holes

    SciTech Connect (OSTI)

    Motamed, Mohammad; Kreiss, H-O. [NADA, Royal Institute of Technology, 10044 Stockholm (Sweden); Albert Einstein Institute, Max Planck Gesellschaft, Am Muehlenberg 1, D-14476 Golm (Germany); Babiuc, M.; Winicour, J. [Albert Einstein Institute, Max Planck Gesellschaft, Am Muehlenberg 1, D-14476 Golm (Germany); Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Szilagyi, B. [Albert Einstein Institute, Max Planck Gesellschaft, Am Muehlenberg 1, D-14476 Golm (Germany)


    In the harmonic description of general relativity, the principal part of Einstein's equations reduces to 10 curved space wave equations for the components of the space-time metric. We present theorems regarding the stability of several evolution-boundary algorithms for such equations when treated in second order differential form. The theorems apply to a model black hole space-time consisting of a spacelike inner boundary excising the singularity, a timelike outer boundary and a horizon in between. These algorithms are implemented as stable, convergent numerical codes and their performance is compared in a 2-dimensional excision problem.

  6. Neural frame classification 1 Walter J Freeman Origin, structure, and role of background EEG activity

    E-Print Network [OSTI]

    Freeman, Walter J.

    -1244 from the National Aeronautics and Space Administration, and EIA- 0130352 from the National Science International Database and Brain Dynamics Centre #12;Neural frame classification

  7. Citizenship Porn within the Frame: Visualizing Techniques, Cyberspace, and the Production of “Undocumented”

    E-Print Network [OSTI]

    Moran, Erin


    Citizenship Porn within the Frame: Visualizing Techniques,pornographic fantasy that I call “citizenship porn”. Let mewhat I mean by “citizenship porn”; I will then raise several

  8. Design for assembly : a computational approach to construct interlocking wooden frames

    E-Print Network [OSTI]

    Tai, Alan Song-Ching


    This thesis explores the computational process of generating and constructing interlocking frames. Its outcome delivers a sophisticated software tool that creates a three dimensional interlocking pattern, analyzes the ...

  9. Primordial black holes and asteroid danger

    E-Print Network [OSTI]

    Alexander Shatskiy


    Probability for a primordial black hole to invade the Kuiper belt was calculated. We showed that primordial black holes of certain masses can significantly change asteroids' orbits. These events may result in disasters, local for our solar system and global for the Earth (like the Tunguska meteorite). We also estimated how often such events occur.

  10. Black holes cannot support conformal scalar hair

    E-Print Network [OSTI]

    T. Zannias


    It is shown that the only static asymptotically flat non-extrema black hole solution of the Einstein-conformally invariant scalar field equations having the scalar field bounded on the horizon, is the Schwarzschild one. Thus black holes cannot be endowed with conformal scalar hair of finite length.

  11. Strings, black holes, and quantum information

    SciTech Connect (OSTI)

    Kallosh, Renata; Linde, Andrei [Department of Physics, Stanford University, Stanford, California 94305 (United States)


    We find multiple relations between extremal black holes in string theory and 2- and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, Bogomol'nyi-Prasad-Sommerfield (BPS) as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with the string theory states with some number of D-branes. We identify a set of large black holes with the maximally entangled Greenberger, Horne, Zeilinger (GHZ) class of states and small black holes with separable, bipartite, and W states. We sort out the relation between 3-qubit states, twistors, octonions, and black holes. We give a simple expression for the entropy and the area of stretched horizon of small black holes in terms of a norm and 2-tangles of a 3-qubit system. Finally, we show that the most general expression for the black hole and black ring entropy in N=8 supergravity/M theory, which is given by the famous quartic Cartan E{sub 7(7)} invariant, can be reduced to Cayley's hyperdeterminant describing the 3-tangle of a 3-qubit state.

  12. Quantum Entropy of Charged Rotating Black Holes

    E-Print Network [OSTI]

    R. B. Mann


    I discuss a method for obtaining the one-loop quantum corrections to the tree-level entropy for a charged Kerr black hole. Divergences which appear can be removed by renormalization of couplings in the tree-level gravitational action in a manner similar to that for a static black hole.

  13. Phosphine Oxide Based Electron Transporting and Hole Blocking...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Oxide Based Electron Transporting and Hole Blocking Materials for Blue Electrophosphorescent Organic Light Emitting Phosphine Oxide Based Electron Transporting and Hole Blocking...

  14. Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues. Three Hydrogen Bond Donor Catalysts: Oxyanion Hole Mimics and Transition State Analogues....

  15. T-623: HP Business Availability Center Input Validation Hole...

    Broader source: (indexed) [DOE]

    3: HP Business Availability Center Input Validation Hole Permits Cross-Site Scripting Attacks T-623: HP Business Availability Center Input Validation Hole Permits Cross-Site...

  16. Black hole and holographic dark energy

    E-Print Network [OSTI]

    Yun Soo Myung


    We discuss the connection between black hole and holographic dark energy. We examine the issue of the equation of state (EOS) for holographic energy density as a candidate for the dark energy carefully. This is closely related to the EOS for black hole, because the holographic dark energy comes from the black hole energy density. In order to derive the EOS of a black hole, we may use its dual (quantum) systems. Finally, a regular black hole without the singularity is introduced to describe an accelerating universe inside the cosmological horizon. Inspired by this, we show that the holographic energy density with the cosmological horizon as the IR cutoff leads to the dark energy-dominated universe with $\\omega_{\\rm \\Lambda}=-1$.

  17. Quantum Black Hole Model and Hawking's Radiation

    E-Print Network [OSTI]

    V. A. Berezin


    The black hole model with a self-gravitating charged spherical symmetric dust thin shell as a source is considered. The Schroedinger-type equation for such a model is derived. This equation appeared to be a finite differences equation. A theory of such an equation is developed and general solution is found and investigated in details. The discrete spectrum of the bound state energy levels is obtained. All the eigenvalues appeared to be infinitely degenerate. The ground state wave functions are evaluated explicitly. The quantum black hole states are selected and investigated. It is shown that the obtained black hole mass spectrum is compatible with the existence of Hawking's radiation in the limit of low temperatures both for large and nearly extreme Reissner-Nordstrom black holes. The above mentioned infinite degeneracy of the mass (energy) eigenvalues may appeared helpful in resolving the well known information paradox in the black hole physics.

  18. Black Hole Thermodynamics Based on Unitary Evolutions

    E-Print Network [OSTI]

    Feng, Yu-Lei


    In this paper, we try to construct black hole thermodynamics based on the fact that, the formation and evaporation of a black hole can be described by quantum unitary evolutions. First, we show that the Bekenstein-Hawking entropy $S_{BH}$ cannot be a Boltzmann or thermal entropy. To confirm this statement, we show that the original black hole's "first law" cannot be treated as the first law of thermodynamics formally, due to some missing metric perturbations caused by matter. Then, by including those (quantum) metric perturbations, we show that the black hole formation and evaporation can be described in a unitary manner effectively, through a quantum channel between the exterior and interior of the event horizon. In this way, the paradoxes of information loss and firewall can be resolved effectively. Finally, we show that black hole thermodynamics can be constructed in an ordinary way, by constructing statistical mechanics.

  19. Fourier Analysis of the BTZ Black Hole

    E-Print Network [OSTI]

    Ian M. Tolfree


    In this paper we extend our previous work regarding the role of the Fourier transformation in bulk to boundary mappings to include the BTZ black hole. We follow standard procedures for modifying Fourier Transformations to accommodate quotient spaces and arrive at a bulk to boundary mapping in a black hole background. We show that this mapping is consistent with known results and lends a new insight into the AdS/CFT duality. We find that the micro-states corresponding to the entropy of a bulk scalar field are the Fourier coefficients on the boundary, which transform under the principal series representation of $SL(2,R)$. Building upon this we present a toy model to analyze the implications of this for the origin of black hole entropy. We find that the black hole micro-states live on the boundary and correspond to the possible emission modes of the black hole

  20. An electromagnetic black hole made of metamaterials

    E-Print Network [OSTI]

    Cheng, Qiang


    Traditionally, a black hole is a region of space with huge gravitational field in the means of general relativity, which absorbs everything hitting it including the light. In general relativity, the presence of matter-energy densities results in the motion of matter propagating in a curved spacetime1, which is similar to the electromagnetic-wave propagation in a curved space and in an inhomogeneous metamaterial2. Hence one can simulate the black hole using electromagnetic fields and metamaterials. In a recent theoretical work, an optical black hole has been proposed based on metamaterials, in which the numerical simulations showed a highly efficient light absorption3. Here we report the first experimental demonstration of electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can absorb electromagnetic waves efficiently coming from all directions due to the local control of electromagnetic fields. Hence the elect...

  1. Fermionic greybody factors in dilaton black holes

    E-Print Network [OSTI]

    Jahed Abedi; Hessamaddin Arfaei


    In this paper the question of emission of fermions in the process of dilaton black hole evolution and its characters for different dilaton coupling constants $\\alpha$ is studied. The main quantity of interest, the greybody factors are calculated both numerically and in analytical approximation. The dependence of rates of evaporation and behaviour on the dilaton coupling constant is analyzed. Having calculated the greybody factors we are able to address the question of the final fate of the dilaton black hole. For that we also need to make dynamical treatment of the solution by considering the backreaction which will show a crucial effect on the final result. We find a transition line in $(Q/M, \\alpha)$ plane that separates the two regimes for the fate of the black hole, decay regime and extremal regime. In the decay regime the black hole completely evaporates, while in the extremal regime the black hole approaches the extremal limit by radiation and becomes stable.

  2. Black holes in Asymptotically Safe Gravity

    E-Print Network [OSTI]

    Saueressig, Frank; D'Odorico, Giulio; Vidotto, Francesca


    Black holes are among the most fascinating objects populating our universe. Their characteristic features, encompassing spacetime singularities, event horizons, and black hole thermodynamics, provide a rich testing ground for quantum gravity ideas. In this note we observe that the renormalization group improved Schwarzschild black holes constructed by Bonanno and Reuter within Weinberg's asymptotic safety program constitute a prototypical example of a Hayward geometry used to model non-singular black holes within quantum gravity phenomenology. Moreover, they share many features of a Planck star: their effective geometry naturally incorporates the one-loop corrections found in the effective field theory framework, their Kretschmann scalar is bounded, and the black hole singularity is replaced by a regular de Sitter patch. The role of the cosmological constant in the renormalization group improvement process is briefly discussed.

  3. Viscous-Fluid-Spring Damper Retrofit of a Steel Moment Frame Structure

    SciTech Connect (OSTI)

    Hussain, Saif [Managing Principal, Coffman Engineers, Inc., 16133 Ventura Blvd., Suite 1010, Encino, California (United States); Van Benschoten, Paul [Principal, Coffman Engineers, Inc., 16133 Ventura Blvd., Suite 1010, Encino, California (United States); Al Satari, Mohamed; Lin, Silian [Structural Engineer, Coffman Engineers, Inc., 16133 Ventura Blvd., Suite 1010, Encino, California (United States)


    The subject building is a peculiar pre-Northridge steel moment resisting frame building. Upon investigating the existing lateral resisting system, numerous significant deficiencies were identified; inherent lack of redundancy, poor geometry and inadequate stiffness of the lateral resisting system. All of which resulted in an extremely soft 5-story structure with a primary torsional mode of vibration at T{sub 1} = 5.46 s. Significant structural modifications were deemed necessary to meet the 'life-safety' performance objective as outlined in rehabilitation standards such as ASCE 41. Both increased stiffness and damping were required to adequately retrofit the building. Furthermore, adjacent building separation as well as deformation compatibility issues needed to be addressed and resolved. A three-dimensional computer model of the building was created using ETABS mathematically simulating the building's dynamic characteristics in its current condition. Multiple seismic retrofit systems were investigated such as Buckling Restrained Braced Frames (BRBF's). However, based on the performance effectiveness and constructability of the retrofit schemes studied, the Viscous-Fluid-Spring Damper (VFSD) system was proposed as the 'optimum' solution for the building. The VFSD, was chosen because it combines the relatively compact size and minimally invasive constructability with the required properties (an elastomeric spring in parallel with a nonlinear velocity dependent viscous damper). A site-specific response spectrum was developed for the Design Basis Earthquake (DBE, 475 year return period) event, and three pairs of representative earthquake horizontal ground motion time-histories were scaled to match this DBE. The proposed scheme reduced the building maximum inter-story drift ratio from 5.4% to about 1%. Similarly, the maximum roof displacement was reduced by about 70% (23'' to 7'')

  4. External Insulation of Masonry Walls and Wood Framed Walls

    SciTech Connect (OSTI)

    Baker, P.


    The use of exterior insulation on a building is an accepted and effective means to increase the overall thermal resistance of the assembly that also has other advantages of improved water management and often increased air tightness of building assemblies. For thin layers of insulation (1" to 1 1/2"), the cladding can typically be attached directly through the insulation back to the structure. For thicker insulation layers, furring strips have been added as a cladding attachment location. This approach has been used in the past on numerous Building America test homes and communities (both new and retrofit applications), and has been proven to be an effective and durable means to provide cladding attachment. However, the lack of engineering data has been a problem for many designers, contractors, and code officials. This research project developed baseline engineering analysis to support the installation of thick layers of exterior insulation on existing masonry and frame walls. Furthermore, water management details necessary to integrate windows, doors, decks, balconies and roofs were created to provide guidance on the integration of exterior insulation strategies with other enclosure elements.

  5. Acceleration of particles near the inner black hole horizon

    E-Print Network [OSTI]

    O. B. Zaslavskii


    We study the possibility of obtaining unbound energy E_{c.m.} in the centre of mass frame when two particles collide near the inner black hole horizon. We consider two different cases - when both particles move (i) in the same direction or (ii) in the opposite ones. We also discuss two different versions of the effect - whether an infinite energy can be released in the collision (strong version) or the energy E_{c.m.} is finite but can be made as large as one likes (weak version). We demonstrate that the strong version of the effect is impossible in both cases (i) and (ii). In case (i) this is due to the fact that in the situation when E_{c.m.} formally diverges on the horizon, one of particles passes through the bifurcation point where two horizons meet while the second particle does not, so collision does not occur. In case (ii), both particles hit different branches of the horizon. The weak version is possible in both cases, provided at least one of particles starts its motion inside the horizon along the direction of spatial symmetry from infinity.

  6. Instabilities and Anti-Evaporation of Reissner-Nordström Black Holes in modified $F(R)$ gravity

    E-Print Network [OSTI]

    Shin'ichi Nojiri; Sergei D. Odintsov


    We study the instabilities and related anti-evaporation of the extremal Reissner-Nordstr\\"om (RN) black hole in $F(R)$ gravity. It is remarkable that the effective electric charge can be generated for some solutions of $F(R)$ gravity without electromagnetic field. The anti-evaporation effect occurs but it emerges only in the strong coupling limit of the effective gravitational coupling. The instabilities of RN black hole are also investigated when the electromagnetic sector is added to the action of $F(R)$ gravity. We show the anti-evaporation occurs in the Maxwell-$F(R)$ gravity with the arbitrary gravitational coupling constant although it does not occur in the Maxwell-Einstein gravity. Furthermore, general spherically-symmetric solution of $F(R)$ gravity in the Einstein frame is obtained.

  7. Dynamics of Scalar Fields in the Background of Rotating Black Holes

    E-Print Network [OSTI]

    W. Krivan; P. Laguna; P. Papadopoulos


    A numerical study of the evolution of a massless scalar field in the background of rotating black holes is presented. First, solutions to the wave equation are obtained for slowly rotating black holes. In this approximation, the background geometry is treated as a perturbed Schwarzschild spacetime with the angular momentum per unit mass playing the role of a perturbative parameter. To first order in the angular momentum of the black hole, the scalar wave equation yields two coupled one-dimensional evolution equations for a function representing the scalar field in the Schwarzschild background and a second field that accounts for the rotation. Solutions to the wave equation are also obtained for rapidly rotating black holes. In this case, the wave equation does not admit complete separation of variables and yields a two-dimensional evolution equation. The study shows that, for rotating black holes, the late time dynamics of a massless scalar field exhibit the same power-law behavior as in the case of a Schwarzschild background independently of the angular momentum of the black hole.

  8. Oscillating axion bubbles as alternative to supermassive black holes at galactic centers

    E-Print Network [OSTI]

    Anatoly A. Svidzinsky


    Recent observations of near-infrared and X-ray flares from Sagittarius A*, which is believed to be a supermassive black hole at the Galactic center, show that the source exhibits about 20-minute periodic variability. Here we provide arguments based on a quantitative analysis that supermassive objects at galactic centers may be bubbles of dark matter axions rather than black holes. An oscillating axion bubble can explain periodic variability of Sagittarius A* and yields the axion mass about 0.6 meV which fits in the open axion mass window. The bubble scenario with no other free parameters explains lack of supermassive "black holes" with mass Maxion bubble can not exceed 1.5\\times 10^9 M_{Sun}, in agreement with the upper limit on the supermassive "black hole" mass obtained from observations. Our finding, if confirmed, suggests that Einstein general relativity is invalid for strong gravity and the gravitational field for the bubble effectively becomes repulsive at large potential. Imaging a shadow of the "black hole" at the Galactic center with VLBI in the next decade can distinguish between the black hole and the oscillating axion bubble scenarios. In the case of axion bubble, a steady shadow will not be observed. Instead, the shadow will appear and disappear periodically with a period of about 20 min.

  9. The Efficiency of Gravitational Bremsstrahlung Production in the Collision of Two Schwarzschild Black Holes

    E-Print Network [OSTI]

    R. F. Aranha; H. P. de Oliveira; I. Damião Soares; E. V. Tonini


    We examine the efficiency of gravitational bremsstrahlung production in the process of head-on collision of two boosted Schwarzschild black holes. We constructed initial data for the characteristic initial value problem in Robinson-Trautman spacetimes, that represent two instantaneously stationary Schwarzschild black holes in motion towards each other with the same velocity. The Robinson-Trautman equation was integrated for these initial data using a numerical code based on the Galerkin method. The final resulting configuration is a boosted black hole with Bondi mass greater than the sum of the individual mass of each initial black hole. Two relevant aspects of the process are presented. The first relates the efficiency $\\Delta$ of the energy extraction by gravitational wave emission to the mass of the final black hole. This relation is fitted by a distribution function of non-extensive thermostatistics with entropic parameter $q \\simeq 1/2$; the result extends and validates analysis based on the linearized theory of gravitational wave emission. The second is a typical bremsstrahlung angular pattern in the early period of emission at the wave zone, a consequence of the deceleration of the black holes as they coalesce; this pattern evolves to a quadrupole form for later times.

  10. Effects of black hole's gravitational field on the luminosity of a star during close encounter

    E-Print Network [OSTI]

    Andreja Gomboc; Andrej Cadez


    To complement hydrodynamic studies of the tidal disruption of the star by a massive black hole, we present the study of stellar luminosity and its variations, produced by the strong gravitational field of the black hole during a close encounter. By simulating the relativistically moving star and its emitted light and taking into account general relativistic effects on particle and light trajectories, our results show that the black hole's gravity alone induces apparent stellar luminosity variations on typical timescales of a few r_g/c (=5 sec m_bh/10^6 M_\\odot) to a few 100 r_g/c (\\sim 10 min m_bh/10^6 M_\\odot), where r_g=Gm_bh/c^2. We discern different cases with respect to the strength of tidal interaction and focus on two: a) a star encountering a giant black hole traces space-time almost as a point particle, so that the apparent luminosity variations are dominated by clearly recognizable general relativistic effects and b) in a close encounter of a star with a black hole of similar size the stellar debris is spread about the black hole by processes where hydrodynamics plays an important role. We discuss limitations and results of our approach.

  11. Simulated Performance of Steel Moment-Resisting Frame Buildings in the ,**-Tokachi-oki Earthquake

    E-Print Network [OSTI]

    Greer, Julia R.

    Simulated Performance of Steel Moment-Resisting Frame Buildings in the ,**- Tokachi-oki Earthquake of Technology Abstract We simulate the response of 0- and ,*-story steel moment-resisting frame buildings (US, our simulations indicate that flexible buildings would have been strongly excited by this earthquake


    E-Print Network [OSTI]

    Maggioni, Mauro

    WAVELET FRAMES ON GROUPS AND HYPERGROUPS VIA DISCRETIZATION OF CALDER´ON FORMULAS MAURO MAGGIONI Abstract. Continuous wavelets are often studied in the general framework of representation theory of square whether these continuous wavelets can be discretized to yield wavelet frames. In this paper we us Calder


    E-Print Network [OSTI]

    Wang, Ji

    411 DAMAGE IDENTIFICATION IN A STEEL FRAME USING HIGH-FREQUENCY ELECTRO-MECHANICAL IMPEDANCE presents an experimental investigation of damage detection of a steel frame using electro damage in structures. Damages are introduced by completely loosening bolts over several locations


    E-Print Network [OSTI]

    California at Santa Barbara, University of

    Technology, Inc., Dolby Laboratories, Inc., Mind- speed Technologies, Inc., and Qualcomm, Inc. candidates character- istics of the reconstructed frames. Surprisingly, the consideration of sinusoidal energy across the lost and adjacent frames, and imposi- tion of constraints on sinusoidal energy evolution, yield exactly

  15. Dynamic Frame Scheduling with Load Balancing for IEEE 802.16j

    E-Print Network [OSTI]

    Jang, Ju-Wook

    Dynamic Frame Scheduling with Load Balancing for IEEE 802.16j Hoon Baek Dept. of Electronic Engineering Sogang University Seoul, Korea Ju Wook Jang Dept. of Electronic a frame scheduling algorithm that improves the overall system throughput by reducing waste of radio

  16. Journal of Embedded Computing 2 (2006) 93102 93 Frame packing algorithms for automotive

    E-Print Network [OSTI]

    Navet, Nicolas


    design is a standard procedure in the automotive industry. The second reason to minimize the bandwidthJournal of Embedded Computing 2 (2006) 93­102 93 IOS Press Frame packing algorithms for automotive Vandoeuvre-l `es-Nancy, France Abstract. The set of frames exchanged in automotive applications must meet two

  17. Using WordNet to Extend FrameNet Coverage Richard Johansson and Pierre Nugues

    E-Print Network [OSTI]

    Nugues, Pierre

    Using WordNet to Extend FrameNet Coverage Richard Johansson and Pierre Nugues Department to address the prob- lem of sparsity in the FrameNet lexical database. The first method is based on the idea using a WordNet- based variant of the Lesk metric. The sec- ond method uses the sequence of synsets

  18. Spatiality of the patch frame Mart'in H. Escard'o

    E-Print Network [OSTI]

    Escardó, Martín

    of a sober space. Keywords: Frame of nuclei, Scott continuous nucleus, patch topology, perfect ma* *p/ _____________________________________________________________________________ Abstract The Scott continuous nuclei form a subframe of the frame of all nuclei. This su* *bframe. Mathematics Subject Classification: 06E15, 54A10

  19. Optimum Frame Synchronization for Preamble-less Packet Transmission of Turbo Codes

    E-Print Network [OSTI]

    Valenti, Matthew C.

    Optimum Frame Synchronization for Preamble-less Packet Transmission of Turbo Codes Jian Sun introduces an optimum maximum a posteriori (MAP) frame synchronization method for packet- based turbo coded the received signal sequences. This method is based on the low- density parity-check properties of turbo codes


    E-Print Network [OSTI]

    Sweetman, Bert

    SEISMIC PERFORMANCE EVALUATION FOR STEEL MOMENT FRAMES By Seung-Yul Yun1 , Ronald O. Hamburger2 , C than existing buildings designed and built with older technologies. Key words: seismic behavior; seismic performance evaluation; performance-based design; earthquake engineering; steel moment frame

  1. Cyclic Testing of a Buckling Restrained Braced Frame with Unconstrained Gusset Connections

    E-Print Network [OSTI]

    Bruneau, Michel

    . Introduction Buckling restrained braced frames BRBFs have been used as seismic and lateral load resistingCyclic Testing of a Buckling Restrained Braced Frame with Unconstrained Gusset Connections Jeffrey W. Berman1 and Michel Bruneau2 Abstract: Buckling restrained braces are intended to yield in both

  2. Muon decays in the Earth's atmosphere, time dilatation and relativity of simultaneity

    E-Print Network [OSTI]

    J. H. Field


    Observation of the decay of muons produced in the Earth's atmosphere by cosmic ray interactions provides a graphic illustration of the counter-intuitive space-time predictions of special relativity theory. Muons at rest in the atmosphere decaying simultaneously are subject to a universal time-dilatation effect when viewed from a moving frame and so are also observed to decay simultaneously in all such frames, whereas the decays of muons with different proper frames show relativity of simultaneity when observed from different inertial frames.

  3. Thermodynamics of Dyonic Lifshitz Black Holes

    E-Print Network [OSTI]

    Tobias Zingg


    Black holes with asymptotic anisotropic scaling are conjectured to be gravity duals of condensed matter system close to quantum critical points with non-trivial dynamical exponent z at finite temperature. A holographic renormalization procedure is presented that allows thermodynamic potentials to be defined for objects with both electric and magnetic charge in such a way that standard thermodynamic relations hold. Black holes in asymptotic Lifshitz spacetimes can exhibit paramagnetic behavior at low temperature limit for certain values of the critical exponent z, whereas the behavior of AdS black holes is always diamagnetic.

  4. Black hole hair in higher dimensions

    E-Print Network [OSTI]

    Chao Cao; Yi-Xin Chen; Jian-Long Li


    We study the property of matter in equilibrium with a static, spherically symmetric black hole in D-dimensional spacetime. It requires this kind of matter has an equation of state (\\omega\\equiv p_r/\\rho=-1/(1+2kn), k,n\\in \\mathbb{N}), which seems to be independent of D. However, when we associate this with specific models, some interesting limits on space could be found: (i)(D=2+2kn) while the black hole is surrounded by cosmic strings; (ii)the black hole can be surrounded by linear dilaton field only in 4-dimensional spacetime. In both cases, D=4 is special.

  5. Radion clouds around evaporating black holes

    E-Print Network [OSTI]

    J. R. Morris


    A Kaluza-Klein model, with a matter source associated with Hawking radiation from an evaporating black hole, is used to obtain a simple form for the radion effective potential. The environmental effect generally causes a matter-induced shift of the radion vacuum, resulting in the formation of a radion cloud around the hole. There is an albedo due to the radion cloud, with an energy dependent reflection coefficient that depends upon the size of the extra dimensions and the temperature of the hole.

  6. Falling through the black hole horizon

    E-Print Network [OSTI]

    Brustein, Ram


    We consider the fate of a small classical object, a "stick", as it falls through the horizon of a large black hole (BH). Classically, the equivalence principle dictates that the stick is affected by small tidal forces, and Hawking's quantum-mechanical model of BH evaporation makes essentially the same prediction. If, on the other hand, the BH horizon is surrounded by a "firewall", the stick will be consumed as it falls through. We have recently extended Hawking's model by taking into account the quantum fluctuations of the geometry and the classical back-reaction of the emitted particles. Here, we calculate the strain exerted on the falling stick for our model. The strain depends on the near-horizon state of the Hawking pairs. We find that, after the Page time when the state of the pairs deviates significantly from maximal entanglement (as required by unitarity), the induced strain in our semiclassical model is still parametrically small. This is because the number of the disentangled pairs is parametrically ...

  7. Molecular-Frame Angular Distributions of Resonant Auger Electrons

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    team of scientists from Western Michigan University, the ALS, and Tohoku University in Japan has successfully used a novel approach to determine for the first time the...

  8. Thermodynamics of Schwarzschild-de Sitter black hole: thermal stability of Nariai black hole

    E-Print Network [OSTI]

    Yun Soo Myung


    We study thermodynamics of the Schwarzschild-de Sitter black hole in five dimensions by introducing two temperatures based on the standard and Bousso-Hawking normalizations. We use the first-law of thermodynamics to derive thermodynamic quantities. The two temperatures indicate that the Nariai black hole is thermodynamically unstable. However, it seems that black hole thermodynamics favors the standard normalization, and does not favor the Bousso-Hawking normalization.

  9. Are black holes a serious threat to scalar field dark matter models?

    E-Print Network [OSTI]

    Juan Barranco; Argelia Bernal; Juan Carlos Degollado; Alberto Diez-Tejedor; Miguel Megevand; Miguel Alcubierre; Darío Núñez; Olivier Sarbach


    Classical scalar fields have been proposed as possible candidates for the dark matter component of the universe. Given the fact that super-massive black holes seem to exist at the center of most galaxies, in order to be a viable candidate for the dark matter halo a scalar field configuration should be stable in the presence of a central black hole, or at least be able to survive for cosmological time-scales. In the present work we consider a scalar field as a test field on a Schwarzschild background, and study under which conditions one can obtain long-lived configurations. We present a detailed study of the Klein-Gordon equation in the Schwarzschild spacetime, both from an analytical and numerical point of view, and show that indeed there exist quasi-stationary solutions that can remain surrounding a black hole for large time-scales.

  10. Hawking radiation as tunneling from a Vaidya black hole in noncommutative gravity

    SciTech Connect (OSTI)

    Mehdipour, S. Hamid [Islamic Azad University, Lahijan Branch, P. O. Box 1616, Lahijan (Iran, Islamic Republic of)


    In the context of a noncommutative model of coordinate coherent states, we present a Schwarzschild-like metric for a Vaidya solution instead of the standard Eddington-Finkelstein metric. This leads to the appearance of an exact (t-r) dependent case of the metric. We analyze the resulting metric in three possible causal structures. In this setup, we find a zero remnant mass in the long-time limit, i.e. an instable black hole remnant. We also study the tunneling process across the quantum horizon of such a Vaidya black hole. The tunneling probability including the time-dependent part is obtained by using the tunneling method proposed by Parikh and Wilczek in terms of the noncommutative parameter {sigma}. After that, we calculate the entropy associated to this noncommutative black hole solution. However, the corrections are fundamentally trifling; one could respect this as a consequence of quantum inspection at the level of semiclassical quantum gravity.

  11. Gödel black hole, closed timelike horizon, and the study of particle emissions

    E-Print Network [OSTI]

    Sourav Bhattacharya; Anirban Saha


    We show that a particle, with positive orbital angular momentum, following an outgoing null/timelike geodesic, shall never reach the closed timelike horizon (CTH) present in the $(4+1)$-dimensional rotating G\\"{o}del black hole space-time. Therefore a large part of this space-time remains inaccessible to a large class of geodesic observers, depending on the conserved quantities associated with them. We discuss how this fact and the existence of the closed timelike curves present in the asymptotic region make the quantum field theoretic study of the Hawking radiation, where the asymptotic observer states are a pre-requisite, unclear. However, the semiclassical approach provides an alternative to verify the Smarr formula derived recently for the rotating G\\"{o}del black hole. We present a systematic analysis of particle emissions, specifically for scalars, charged Dirac spinors and vectors, from this black hole via the semiclassical complex path method.

  12. The runaway instability of thick discs around black holes. II. Non constant angular momentum discs

    E-Print Network [OSTI]

    Frederic Daigne; Jose A. Font


    We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results where only constant angular momentum discs were considered. All relevant aspects of the theory of stationary thick discs around rotating black holes, necessary to build the initial state in our simulations, are presented in great detail. The angular momentum of the discs is assumed to increase outwards with the radial distance according to a power law. The main simplifying assumptions of our approach are not to include magnetic fields and self-gravity in the discs. Furthermore, the dynamics of the spacetime is accounted for by computing the transfer of mass and angular momentum from the disc to the black hole through the event horizon : the evolution of the central black hole is assumed to follow a sequence of Kerr black holes of increasing mass and spin. In agreement with previous results based on stationary models we find that by allowing the mass and the spin of the black hole to grow, constant angular momentum discs rapidly become unstable on a dynamical timescale. The comparison with the results of paper I shows that the effect of the angular momentum transfer from the torus to the black hole is to make constant angular momentum discs less unstable, increasing the timescale of the instability. However, we find that non-constant angular momentum discs are dramatically stabilized for very small values of the angular momentum slope. Our time-dependent simulations confirm, thus, the predictions of stationary studies concerning the stabilizing effect of non-constant angular momentum distributions.

  13. Tucker Wireline Open Hole Wireline Logging

    SciTech Connect (OSTI)

    Milliken, M.


    The Tucker Wireline unit ran a suite of open hole logs right behind the RMOTC logging contractor for comparison purposes. The tools included Dual Laterolog, Phased Induction, BHC Sonic, and Density-Porosity.

  14. Towards Black Hole Entropy in Shape Dynamics

    E-Print Network [OSTI]

    Gabriel Herczeg; Vasudev Shyam


    Shape dynamics is classical theory of gravity which agrees with general relativity in many important cases, but possesses different gauge symmetries and constraints. Rather than spacetime diffeomorphism invariance, shape dynamics takes spatial diffeomorphism invariance and spatial Weyl invariance as the fundamental gauge symmetries associated with the gravitational field. Since the area of the event horizon of a black hole transforms under a generic spatial Weyl transformation, there has been some doubt that one can speak sensibly about the thermodynamics of black holes in shape dynamics. The purpose of this paper is to show that by treating the event horizon of a black hole as an interior boundary, one can recover familiar notions of black hole thermodynamics in shape dynamics and define a gauge invariant entropy that agrees with general relativity.

  15. Multipole moments of bumpy black holes

    E-Print Network [OSTI]

    Vigeland, Sarah Jane

    General relativity predicts the existence of black holes, compact objects whose spacetimes depend only on their mass, spin, and charge in vacuum (the “no-hair” theorem). As various observations probe deeper into the strong ...

  16. Hole Coupling Resonator for Free Electron Lasers

    E-Print Network [OSTI]

    Xie, M.


    3. Total round-trip power loss, coupling efficiency and themicron. Total round-trip power loss and coupling efficiencythe total fractional power loss per round trip, the hole

  17. Black Hole Thermodynamics in Modified Gravity

    E-Print Network [OSTI]

    Jonas R. Mureika; John W. Moffat; Mir Faizal


    We analyze the thermodynamics of a non-rotating and rotating black hole in a modified theory of gravity that includes scalar and vector modifications to general relativity, which results in a modified gravitational constant $G = G_N(1+\\alpha)$ and a new gravitational charge $Q = \\sqrt{\\alpha G_N}M$. The influence of the parameter $\\alpha$ alters the non-rotating black hole's lifetime, temperature and entropy profiles from the standard Schwarzschild case. The thermodynamics of a rotating black hole is analyzed and it is shown to possess stable, cold remnants. The thermodynamic properties of a vacuum solution regular at $r=0$ are investigated and the solution without a horizon called a "gray hole" is not expected to possess an information loss problem.

  18. Energy of 4-Dimensional Black Hole, etc

    E-Print Network [OSTI]

    Dmitriy Palatnik


    In this letter I suggest possible redefinition of mass density, not depending on speed of the mass element, which leads to a more simple stress-energy for an object. I calculate energy of black hole.

  19. Anosov maps with rectangular holes. Nonergodic cases.

    E-Print Network [OSTI]

    Ingenier'ia. Universidad de la Rep'ublica C.C. 30, Montevideo, Uruguay E­mail:; Fax: (598 Partially supported by CONICYT (Uruguay). 1 #12; Running head: Anosov maps with rectangular holes Address

  20. Horizon Operator Approach to Black Hole Quantization

    E-Print Network [OSTI]

    G. 't Hooft


    The $S$-matrix Ansatz for the construction of a quantum theory of black holes is further exploited. We first note that treating the metric tensor $g_{\\m\

  1. Spacetime constraints on accreting black holes

    SciTech Connect (OSTI)

    Garofalo, David [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California 91109 (United States)


    We study the spin dependence of accretion onto rotating Kerr black holes using analytic techniques. In its linear regime, angular momentum transport in MHD turbulent accretion flow involves the generation of radial magnetic field connecting plasma in a differentially rotating flow. We take a first principles approach, highlighting the constraint that limits the generation and amplification of radial magnetic fields, stemming from the transfer of energy from mechanical to magnetic form. Because the energy transferred in magnetic form is ultimately constrained by gravitational potential energy or Killing energy, the spin dependence of the latter allows us to derive spin-dependent constraints on the success of the accreting plasma to expel its angular momentum. We find an inverse relationship between this ability and black hole spin. If this radial magnetic field generation forms the basis for angular momentum transfer in accretion flows, accretion rates involving Kerr black holes are expected to be lower as the black hole spin increases in the prograde sense.

  2. Scattering map for two black holes

    E-Print Network [OSTI]

    Alessandro P. S. de Moura; Patricio S. Letelier


    We study the motion of light in the gravitational field of two Schwarzschild black holes, making the approximation that they are far apart, so that the motion of light rays in the neighborhood of one black hole can be considered to be the result of the action of each black hole separately. Using this approximation, the dynamics is reduced to a 2-dimensional map, which we study both numerically and analytically. The map is found to be chaotic, with a fractal basin boundary separating the possible outcomes of the orbits (escape or falling into one of the black holes). In the limit of large separation distances, the basin boundary becomes a self-similar Cantor set, and we find that the box-counting dimension decays slowly with the separation distance, following a logarithmic decay law.

  3. Radioactive hot cell access hole decontamination machine

    DOE Patents [OSTI]

    Simpson, William E. (Richland, WA)


    Radioactive hot cell access hole decontamination machine. A mobile housing has an opening large enough to encircle the access hole and has a shielding door, with a door opening and closing mechanism, for uncovering and covering the opening. The housing contains a shaft which has an apparatus for rotating the shaft and a device for independently translating the shaft from the housing through the opening and access hole into the hot cell chamber. A properly sized cylindrical pig containing wire brushes and cloth or other disks, with an arrangement for releasably attaching it to the end of the shaft, circumferentially cleans the access hole wall of radioactive contamination and thereafter detaches from the shaft to fall into the hot cell chamber.

  4. Thermodynamics and evaporation of the noncommutative black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Yong-Wan Kim; Young-Jai Park


    We investigate the thermodynamics of the noncommutative black hole whose static picture is similar to that of the nonsingular black hole known as the de Sitter-Schwarzschild black hole. It turns out that the final remnant of extremal black hole is a thermodynamically stable object. We describe the evaporation process of this black hole by using the noncommutativity-corrected Vaidya metric. It is found that there exists a close relationship between thermodynamic approach and evaporation process.

  5. Spacetime noncommutative effect on black hole as particle accelerators

    E-Print Network [OSTI]

    Chikun Ding; Changqing Liu; Qian Guo


    We study the spacetime noncommutative effect on black hole as particle accelerators and, find that particle falling from infinity with zero velocity cannot collide with unbound energy when the noncommutative Kerr black hole is exactly extremal. Our results also show that the bigger of the spinning black hole's mass is, the higher of center of mass energy that the particles obtain. For small and medium noncommutative Schwarzschild black hole, the collision energy depends on the black holes' mass.

  6. Comment on "Black holes constrain varying constants"

    E-Print Network [OSTI]

    V. V. Flambaum


    A recent paper [DDL] claims that the increase of the proton electric charge e leads to a (forbidden) decrease of black hole entropy, therefore, possible evidence for variation of $\\alpha=e^2/\\hbar c$ [alpha] must be interpreted as a decrease of the speed of light. We argue that purely theoretical consideration of black holes possibly cannot give any model-independent limitations on variation of fundamental constants.

  7. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Martinec, Emil J


    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  8. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec


    Combining a variety of results in string theory and general relativity, a picture of the black hole interior is developed wherein spacetime caps off at an inner horizon, and the inter-horizon region is occupied by a Hagedorn gas of a very low tension state of fractionated branes. This picture leads to natural resolutions of a variety of puzzles concerning quantum black holes. Gravity Research Foundation 2015 Fourth Prize Award for Essays on Gravitation.

  9. Local temperature for dynamical black holes

    E-Print Network [OSTI]

    Sean A. Hayward; R. Di Criscienzo; M. Nadalini; L. Vanzo; S. Zerbini


    A local Hawking temperature was recently derived for any future outer trapping horizon in spherical symmetry, using a Hamilton-Jacobi tunneling method, and is given by a dynamical surface gravity as defined geometrically. Descriptions are given of the operational meaning of the temperature, in terms of what observers measure, and its relation to the usual Hawking temperature for static black holes. Implications for the final fate of an evaporating black hole are discussed.

  10. Notes on Black Hole Fluctuations and Backreaction

    E-Print Network [OSTI]

    B. L. Hu; Alpan Raval; Sukanya Sinha


    In these notes we prepare the ground for a systematic investigation into the issues of black hole fluctuations and backreaction by discussing the formulation of the problem, commenting on possible advantages and shortcomings of existing works, and introducing our own approach via a stochastic semiclassical theory of gravity based on the Einstein-Langevin equation and the fluctuation-dissipation relation for a self-consistent description of metric fluctuations and dissipative dynamics of the black hole with backreaction of its Hawking radiance.

  11. EM counterparts of recoiling black holes: general relativistic simulations of non-Keplerian discs

    E-Print Network [OSTI]

    Olindo Zanotti; Luciano Rezzolla; Luca Del Zanna; Carlos Palenzuela


    We investigate the dynamics of a circumbinary disc that responds to the loss of mass and to the recoil velocity of the black hole produced by the merger of a binary system of supermassive black holes. We perform the first two-dimensional general relativistic hydrodynamics simulations of \\textit{extended} non-Keplerian discs and employ a new technique to construct a "shock detector", thus determining the precise location of the shocks produced in the accreting disc by the recoiling black hole. In this way we can study how the properties of the system, such as the spin, mass and recoil velocity of the black hole, affect the mass accretion rate and are imprinted on the electromagnetic emission from these sources. We argue that the estimates of the bremsstrahlung luminosity computed without properly taking into account the radiation transfer yield cooling times that are unrealistically short. At the same time we show, through an approximation based on the relativistic isothermal evolution, that the luminosity produced can reach a peak value above $L \\simeq 10^{43} \\ {\\rm erg/s} $ at about $\\sim 30\\,{\\rm d}$ after the merger of a binary with total mass $M\\simeq 10^6 M_\\odot$ and persist for several days at values which are a factor of a few smaller. If confirmed by more sophisticated calculations such a signal could indeed lead to an electromagnetic counterpart of the merger of binary black-hole system.

  12. Independent set problems and odd-hole-preserving graph reductions

    E-Print Network [OSTI]

    Warren, Jeffrey Scott


    . The algorithm will exploit and extend the best techniques from previous solvers that use clique covers to provide their bounds. We will investigate the polynomial-time detection of sets U V such that G[U] contains an odd hole if G does. We will analyze... having the highest degree in G[U] are favored. Further ties are broken arbitrarily. To achieve the desired partition of V, we do the following. Let U V and let T be the vertex set of a vertex-maximal CIS in G[U]. Then let U UnT and repeat, retaining...

  13. Density perturbations in braneworld cosmology and primordial black holes

    SciTech Connect (OSTI)

    Bugaev, Edgar; Klimai, Peter [Institute for Nuclear Research, Russian Academy of Sciences, 60th October Anniversary Prospect 7a, 117312 Moscow (Russian Federation)


    We study, by numerical methods, the time evolution of scalar perturbations in radiation era of Randall-Sundrum braneworld cosmology. Our results confirm an existence of the enhancement of perturbation amplitudes (near horizon crossing), discovered recently. We suggest the approximate solution of equations of the perturbation theory in the high-energy regime, which predicts that the enhancement factor is asymptotically constant, as a function of scale. We discuss the application of this result for the problem of primordial black hole production in braneworld cosmology.

  14. Equilibrium temperature anisotropy and black-hole analogues

    E-Print Network [OSTI]

    Daniel K. L. Oi; Jonathan Oppenheim


    When long-range interactions are present the usual definition of temperature implies that two systems in thermal equilibrium can be at different temperatures. This local temperature has physical significance, if the sub-systems cease to interact, each system will be at their different local temperatures. This is formally related to redshifting of temperature in general relativity. We propose experiments to test this effect which are feasible using current microfabrication techniques. It is also possible to display thermodynamical analogues to black-hole space-time.

  15. Probing embryonic tissue mechanics with laser hole-drilling

    E-Print Network [OSTI]

    Ma, Xiaoyan; Scully, Peter C; Hutson, M Shane


    We have used laser hole-drilling to assess mechanical changes in an embryonic epithelium during development - in vivo and with subcellular resolution. This method uses a single laser pulse to ablate a cylindrical hole (1 micron in diameter, 5-7 micron tall) clean through the epithelium, and tracks the subsequent recoil of adjacent cells (with ms time resolution). We investigate dorsal closure in the fruit fly with emphasis on apical constriction of amnioserosa cells. We find that substantial in-plane tension is carried across each cell surface and not just along cell-cell interfaces. In early phases of constriction, the tension is 1.6-fold greater along cell-cell interfaces. Later, the two tensions are indistinguishable. Other changes associated with constriction include a decrease in the characteristic recoil times and an increased anisotropy. The smaller time constants imply a more solid-like tissue. The anisotropy matches changes in the underlying quasi-hexagonal cellular mesh. The results of these laser h...

  16. Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools

    SciTech Connect (OSTI)

    Gustavsen, Arild; Arasteh, Dariush; Jelle, Bjorn Petter; Curcija, Charlie; Kohler, Christian


    While window frames typically represent 20-30% of the overall window area, their impact on the total window heat transfer rates may be much larger. This effect is even greater in low-conductance (highly insulating) windows that incorporate very low-conductance glazing. Developing low-conductance window frames requires accurate simulation tools for product research and development. Based on a literature review and an evaluation of current methods of modeling heat transfer through window frames, we conclude that current procedures specified in ISO standards are not sufficiently adequate for accurately evaluating heat transfer through the low-conductance frames. We conclude that the near-term priorities for improving the modeling of heat transfer through low-conductance frames are: (1) Add 2D view-factor radiation to standard modeling and examine the current practice of averaging surface emissivity based on area weighting and the process of making an equivalent rectangular frame cavity. (2) Asses 3D radiation effects in frame cavities and develop recommendation for inclusion into the design fenestration tools. (3) Assess existing correlations for convection in vertical cavities using CFD. (4) Study 2D and 3D natural convection heat transfer in frame cavities for cavities that are proven to be deficient from item 3 above. Recommend improved correlations or full CFD modeling into ISO standards and design fenestration tools, if appropriate. (5) Study 3D hardware short-circuits and propose methods to ensure that these effects are incorporated into ratings. (6) Study the heat transfer effects of ventilated frame cavities and propose updated correlations.

  17. Seismic fragility estimates for reinforced concrete framed buildings

    E-Print Network [OSTI]

    Ramamoorthy, Sathish Kumar


    story drift given the spectral acceleration at the fundamental period of the building. The unknown parameters of the demand models are estimated using the simulated response data obtained from nonlinear time history analyses of the structural models...

  18. Introducing Abuse Frames for Analysing Security Requirements Luncheng Lin Bashar Nuseibeh Darrel Ince Michael Jackson Jonathan Moffett

    E-Print Network [OSTI]

    Nuseibeh, Bashar

    a focus for early security threat analysis. Traditional information security development methods haveIntroducing Abuse Frames for Analysing Security Requirements Luncheng Lin Bashar Nuseibeh Darrel using Jackson's Problem Frames to analyse security problems in order to determine security

  19. Calculation of Eddy Currents In the CTH Vacuum Vessel and Coil Frame

    SciTech Connect (OSTI)

    A. Zolfaghari, A. Brooks, A. Michaels, J. Hanson, and G. Hartwell


    Knowledge of eddy currents in the vacuum vessel walls and nearby conducting support structures can significantly contribute to the accuracy of Magnetohydrodynamics (MHD) equilibrium reconstruction in toroidal plasmas. Moreover, the magnetic fields produced by the eddy currents could generate error fields that may give rise to islands at rational surfaces or cause field lines to become chaotic. In the Compact Toroidal Hybrid (CTH) device (R0 = 0.75 m, a = 0.29 m, B ? 0.7 T), the primary driver of the eddy currents during the plasma discharge is the changing flux of the ohmic heating transformer. Electromagnetic simulations are used to calculate eddy current paths and profile in the vacuum vessel and in the coil frame pieces with known time dependent currents in the ohmic heating coils. MAXWELL and SPARK codes were used for the Electromagnetic modeling and simulation. MAXWELL code was used for detailed 3D finite-element analysis of the eddy currents in the structures. SPARK code was used to calculate the eddy currents in the structures as modeled with shell/surface elements, with each element representing a current loop. In both cases current filaments representing the eddy currents were prepared for input into VMEC code for MHD equilibrium reconstruction of the plasma discharge. __________________________________________________

  20. Larmor radius size density holes discovered in the solar wind upstream of Earth's bow shock

    E-Print Network [OSTI]

    California at Berkeley, University of

    Larmor radius size density holes discovered in the solar wind upstream of Earth's bow shock G. K. Cao Key Laboratory for Space Weather, CSSAR, CAS, Beijing, China K. Meziane Physics Department that are five or more times the solar wind density. Particle distributions show the steepened edge can behave

  1. State-of-the-Art Highly Insulating Window Frames - Research and Market Review

    E-Print Network [OSTI]

    Gustavsen, Arild


    analysis investigation of a PVC window frame naturally agedThermix / TGI-wave 1.23 x 1.48 PVC profile with PUR (? =TOPLINE Plus Rahmenmaterial: PVC- Profile, Kammern mit PU

  2. Laser wakefield simulation using a speed-of-light frame envelope model

    E-Print Network [OSTI]

    Cowan, B.


    Laser wake?eld simulation using a speed-of-light frameAbstract. Simulation of laser wake?eld accelerator (LWFA)extend hundreds of laser wave- lengths transversely and many

  3. Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Converting Hybrid Wire-frames to B-rep Models Jie-Hui Gong Dept. of Comp. Sci. and Technol of curved surfaces [Liu et al. 2001; Gong et al. 2006b]. The CSG oriented approach, however, is generally


    E-Print Network [OSTI]


  5. Thermal properties of structural details in wood frame homes : analysis and recommendations

    E-Print Network [OSTI]

    Graybeal, Alexander Kung


    The wood platform frame home is the dominant design in the United States when it comes to single family housing. Introduced during the mid-nineteenth century, the scheme is a cheap, fast, and proven design that takes ...

  6. Usage of Friction-damped Braced Frames for Seismic Vibration Control

    E-Print Network [OSTI]

    Fink, Brynnan 1992-


    This study presents the results of experimental work that examines the functionality of friction-damped braced frames during seismic events. The simplicity and efficacy of this friction device as a means of passive vibration control suggest...

  7. Quadrature Rotating-Frame Gradient Fields for Ultra-Low Field Nuclear Magnetic Resonance and Imaging

    E-Print Network [OSTI]

    Bouchard, Louis-Serge


    Frame Gradient Fields For Ultra-Low Field Nuclear Magneticslow, as in the limit of ultra-low ?elds. In the ?rst case,B. Slice selection in ultra-low ?elds We ?rst examine the

  8. Phase-Change Frame Walls (PCFWs) for Peak Demand Reduction, Load Shifting, Energy Conservation and Comfort

    E-Print Network [OSTI]

    Medina, M.; Stewart, R.

    This paper presents results of side-by-side experimental testing of a technology, referred to as Phase Change Frame Wall (PCFW), whose primary purpose is to increase building thermal mass by the application of phase change materials (PCMs...


    E-Print Network [OSTI]

    Fawley, William


    FULL ELECTROMAGNETIC FEL SIMULATION VIA THE LORENTZ-BOOSTEDrest frame), the red-shifted FEL radiation and blue-shiftedper- mit direct study of FEL problems for which the eikonal

  10. The Behaviour of Multi-storey Composite Steel Framed Structures in Response to Compartment Fires 

    E-Print Network [OSTI]

    Lamont, Susan

    For many years, the ability of highly redundant composite framed structure to resist the effect of a fire have been undervalued and misunderstood. A great deal of work on the behavior of composite steel-concrete structures ...

  11. Performance-Based Seismic Demand Assessment of Concentrically Braced Steel Frame Buildings

    E-Print Network [OSTI]

    Chen, Chui-Hsin


    and Ductility Factors for Steel Frames De- signed According1980), Inelastic Buckling of Steel Struts Under Cyclic LoadBS 5950: Structural use of steel work in building. Part1

  12. The design of a frame for an all terrain, lever propelled wheelchair

    E-Print Network [OSTI]

    Walton, John Michael


    This thesis outlines the process of designing a frame for the Leveraged Freedom Chair (LFC) Prime, an all-terrain levered powered wheelchair designed to improve the mobility of disabled individuals. This design allows for ...

  13. Experimental and Numerical Examination of the Thermal Transmittance of High Performance Window Frames

    E-Print Network [OSTI]

    Gustavsen Ph.D., Arild


    windows are often called passive -house wind ows, as windowse window frames, like passive-house windows. In this p aperare supposed to satisfy the Passive house requirements of

  14. Measuring Hawking Radiation of a Kerr-Newman Black Hole in a Superconducting Transmission Line

    E-Print Network [OSTI]

    X. G. Lan; D. Y. Chen; L. F. Wei


    Applying a dimensional reduction technique and a coordinates transformation approach, we deduce the Kerr-Newman space-time into a Painlev\\'{e}-like form, and obtain its corresponding event horizon and the Hawking radiation temperature. We find that, the event horizon of a Kerr-Newman black hole can be simulated in a superconducting transmission line. Moreover, by running some numerical simulation, we confirm that the Hawking radiation of a Kerr-Newman Black Hole can be experimentally measured in a superconducting transmission line.

  15. Black Hole Entropy and the Dimensional Continuation of the Gauss-Bonnet Theorem

    E-Print Network [OSTI]

    Bañados, Máximo; Zanelli, Jorge; 10.1103/PhysRevLett.72.957


    The Euclidean black hole has topology $\\Re^2 \\times {\\cal S}^{d-2}$. It is shown that -in Einstein's theory- the deficit angle of a cusp at any point in $\\Re^2$ and the area of the ${\\cal S}^{d-2}$ are canonical conjugates. The black hole entropy emerges as the Euler class of a small disk centered at the horizon multiplied by the area of the ${\\cal S}^{d-2}$ there.These results are obtained through dimensional continuation of the Gauss-Bonnet theorem. The extension to the most general action yielding second order field equations for the metric in any spacetime dimension is given.

  16. ROAMing terrain (Real-time Optimally Adapting Meshes)

    SciTech Connect (OSTI)

    Duchaineau, M.; Wolinsky, M.; Sigeti, D.E.; Miller, M.C.; Aldrich, C.; Mineev, M.


    Terrain visualization is a difficult problem for applications requiring accurate images of large datasets at high frame rates, such as flight simulation and ground-based aircraft testing using synthetic sensor stimulation. On current graphics hardware, the problem is to maintain dynamic, view-dependent triangle meshes and texture maps that produce good images at the required frame rate. We present an algorithm for constructing triangle meshes that optimizes flexible view-dependent error metrics, produces guaranteed error bounds, achieves specified triangle counts directly, and uses frame-to-frame coherence to operate at high frame rates for thousands of triangles per frame. Our method, dubbed Real-time Optimally Adapting Meshes (ROAM), uses two priority queues to drive split and merge operations that maintain continuous triangulations built from pre-processed bintree triangles. We introduce two additional performance optimizations: incremental triangle stripping and priority-computation deferral lists. ROAM execution time is proportionate to the number of triangle changes per frame, which is typically a few percent of the output mesh size, hence ROAM performance is insensitive to the resolution and extent of the input terrain. Dynamic terrain and simple vertex morphing are supported.

  17. Framing the Past: How Virtual Experience Affects Bodily Description of Artefacts

    E-Print Network [OSTI]

    Franco, Paola Di Giuseppantonio Di; Matthews, Justin L.; Matlock, Teenie


    Framing the Past: How Virtual Experience Affects Bodily Description of Artefacts Paola Di Giuseppantonio Di Franco1, Justin L. Matthews2, and Teenie Matlock3 1. Marie Curie Fellow, University of Cambridge, McDonald Institute for Archaeological... for virtual reproduction in research, education, and communication in archaeology are discussed. Key Words: 3D digital replicas, 3D prints, embodied cognition, embodiment, perception, gestures, discourse, artefacts, frames, experience. ***** Paola Di...

  18. Finite frames for K4.3 S5 are decidable Department of Informatics

    E-Print Network [OSTI]

    Kurucz, Agi

    Finite frames for K4.3 × S5 are decidable Agi Kurucz Department of Informatics King's College for every L between the product logics K × K × K and S5 × S5 × S5. Here we show that the finite frame problem for the modal product logic K4.3 × S5 is decidable. K4.3 × S5 is outside the scope of both

  19. Holographic superconductor in the exact hairy black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Chanyong Park


    We study the charged black hole of hyperbolic horizon with scalar hair (charged Martinez-Troncoso-Zanelli: CMTZ black hole) as a model of analytic hairy black hole for holographic superconductor. For this purpose, we investigate the second order phase transition between CMTZ and hyperbolic Reissner-Nordstr\\"om-AdS (HRNAdS) black holes. However, this transition unlikely occur. As an analytic treatment for holographic superconductor, we develop superconductor in the bulk and superfluidity on the boundary using the CMTZ black hole below the critical temperature. The presence of charge destroys the condensates around the zero temperature, which is in accord with the thermodynamic analysis of the CMTZ black hole.

  20. Thermalization with chemical potentials, and higher spin black holes

    E-Print Network [OSTI]

    Gautam Mandal; Ritam Sinha; Nilakash Sorokhaibam


    We study the long time behaviour of local observables following a quantum quench in 1+1 dimensional conformal field theories possessing additional conserved charges besides the energy. We show that the expectation value of an arbitrary string of {\\it local} observables supported on a finite interval exponentially approaches an equilibrium value. The equilibrium is characterized by a temperature and chemical potentials defined in terms of the quenched state. For an infinite number of commuting conserved charges, the equilibrium ensemble is a generalized Gibbs ensemble (GGE). We compute the thermalization rate in a systematic perturbation in the chemical potentials, using a new technique to sum over an infinite number of Feynman diagrams. The above technique also allows us to compute relaxation times for thermal Green's functions in the presence of an arbitrary number of chemical potentials. In the context of a higher spin (hs[\\lambda]) holography, the partition function of the final equilibrium GGE is known to agree with that of a higher spin black hole. The thermalization rate from the CFT computed in our paper agrees with the quasinormal frequency of a scalar field in this black hole.

  1. Key Elements of and Materials Performance Targets for Highly Insulating Window Frames

    SciTech Connect (OSTI)

    Gustavsen, Arild; Grynning, Steinar; Arasteh, Dariush; Jelle, Bjorn Petter; Goudey, Howdy


    The thermal performance of windows is important for energy efficient buildings. Windows typically account for about 30-50 percent of the transmission losses though the building envelope, even if their area fraction of the envelope is far less. The reason for this can be found by comparing the thermal transmittance (U-factor) of windows to the U-factor of their opaque counterparts (wall, roof and floor constructions). In well insulated buildings the U-factor of walls, roofs an floors can be between 0.1-0.2 W/(m2K). The best windows have U-values of about 0.7-1.0. It is therefore obvious that the U-factor of windows needs to be reduced, even though looking at the whole energy balance for windows (i.e. solar gains minus transmission losses) makes the picture more complex.In high performance windows the frame design and material use is of utmost importance, as the frame performance is usually the limiting factor for reducing the total window U-factor further. This paper describes simulation studies analyzing the effects on frame and edge-of-glass U-factors of different surface emissivities as well as frame material and spacer conductivities. The goal of this work is to define materials research targets for window frame components that will result in better frame thermal performance than is exhibited by the best products available on the market today.

  2. Anomalous Flyby in the Non-Prefered Reference Frame of the Rotating Earth

    E-Print Network [OSTI]

    Walter Petry


    Several spacecrafts show an anomalous flyby. In a previous paper a non-prefered reference frame is studied moving uniformly relative to the prefered one. In this article the Doppler frequency residual is derived. The prefered reference frame is given by the isotropy of the CMB and the non-prefered one is the Earth. The resulting jump is much too small to explain the measured anomalous flybys of the different spacecrafts. Therefore, the transformations from the prefered frame to the non-prefered frame are replaced by the corresponding total differentials. A formula for the Doppler frequency residual is derived. It is applied to the prefered frame of the Earth and the non-prefered frame of the rotating Earth. The resulting Doppler residual depends on the direction of the velocity of the spacecraft and the position of the observer on the rotating Earth. It is similar to the experimental formula of Anderson et al. which is independent of the position of the observer.

  3. The Environmental Impact of Supermassive Black Holes

    E-Print Network [OSTI]

    Abraham Loeb


    The supermassive black holes observed at the centers of almost all present-day galaxies, had a profound impact on their environment. I highlight the principle of self-regulation, by which supermassive black holes grow until they release sufficient energy to unbind the gas that feeds them from their host galaxy. This principle explains several observed facts, including the correlation between the mass of a central black hole and the depth of the gravitational potential well of its host galaxy, and the abundance and clustering properties of bright quasars in the redshift interval of z~2-6. At lower redshifts, quasars might have limited the maximum mass of galaxies through the suppression of cooling flows in X-ray clusters. The seeds of supermassive black holes were likely planted in dwarf galaxies at redshifts z>10, through the collapse of massive or supermassive stars. The minimum seed mass can be identified observationally through the detection of gravitational waves from black hole binaries by Advanced LIGO or LISA. Aside from shaping their host galaxies, quasar outflows filled the intergalactic medium with magnetic fields and heavy elements. Beyond the reach of these outflows, the brightest quasars at z>6 have ionized exceedingly large volumes of gas (tens of comoving Mpc) prior to global reionization, and must have suppressed the faint end of the galaxy luminosity function in these volumes before the same occurred through the rest of the universe.

  4. Perturbative String Thermodynamics near Black Hole Horizons

    E-Print Network [OSTI]

    Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov


    We provide further computations and ideas to the problem of near-Hagedorn string thermodynamics near (uncharged) black hole horizons, building upon our earlier work JHEP 1403 (2014) 086. The relevance of long strings to one-loop black hole thermodynamics is emphasized. We then provide an argument in favor of the absence of $\\alpha'$-corrections for the (quadratic) heterotic thermal scalar action in Rindler space. We also compute the large $k$ limit of the cigar orbifold partition functions (for both bosonic and type II superstrings) which allows a better comparison between the flat cones and the cigar cones. A discussion is made on the general McClain-Roth-O'Brien-Tan theorem and on the fact that different torus embeddings lead to different aspects of string thermodynamics. The black hole/string correspondence principle for the 2d black hole is discussed in terms of the thermal scalar. Finally, we present an argument to deal with arbitrary higher genus partition functions, suggesting the breakdown of string perturbation theory (in $g_s$) to compute thermodynamical quantities in black hole spacetimes.

  5. Black Holes with Flavors of Quantum Hair?

    E-Print Network [OSTI]

    Gia Dvali


    We show that black holes can posses a long-range quantum hair of super-massive tensor fields, which can be detected by Aharonov-Bohm tabletop interference experiments, in which a quantum-hairy black hole, or a remnant particle, passes through the loop of a magnetic solenoid. The long distance effect does not decouple for an arbitrarily high mass of the hair-providing field. Because Kaluza-Klein and String theories contain infinite number of massive tensor fields, we study black holes with quantum Kaluza-Klein hair. We show that in five dimensions such a black hole can be interpreted as a string of `combed' generalized magnetic monopoles, with their fluxes confined along it. For the compactification on a translation-invariant circle, this substructure uncovers hidden flux conservation and quantization of the monopole charges, which constrain the quantum hair of the resulting four-dimensional black hole. For the spin-2 quantum hair this result is somewhat unexpected, since the constituent `magnetic' charges have no `electric' counterparts. Nevertheless, the information about their quantization is encoded in singularity.

  6. Modulational instability of electrostatic acoustic waves in an electron-hole semiconductor quantum plasma

    SciTech Connect (OSTI)

    Wang, Yunliang, E-mail:; Lü, Xiaoxia [Department of Physics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083 (China)] [Department of Physics, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083 (China)


    The modulational instability of quantum electrostatic acoustic waves in electron-hole quantum semiconductor plasmas is investigated using the quantum hydrodynamic model, from which a modified nonlinear Schrödinger equation with damping effects is derived using the reductive perturbation method. Here, we consider the combined effects of quantum recoil, quantum degenerate pressures, as well as the exchange-correlation effect standing for the electrons (holes) spin. The modulational instability for different semiconductors (GaAs, GaSb, and InP) is discussed. The collision between electron (hole) and phonon is also investigated. The permitted maximum time for modulational instability and the damping features of quantum envelope solitary wave are all determined by the collision. The approximate solitary solution with damping effects is presented in weak collision limit. The damping properties were discussed by numerical method.

  7. Transient evolution of solitary electron holes in low pressure laboratory plasma

    E-Print Network [OSTI]

    Choudhary, Mangilal; Mukherjee, Subroto


    Solitary electrons holes (SEHs) are localized electrostatic positive potential structures in collisionless plasmas. These are vortex-like structures in the electron phase space. Its existence is cause of distortion of the electron distribution in the resonant region. These are explained theoretically first time by Schamel [Phys. Scr. 20, 336 (1979) and Phys. Plasmas 19, 020501 (2012)]. Propagating solitary electron holes can also be formed in a laboratory plasma when a fast rising high positive voltage pulse is applied to a metallic electrode [Kar et. al., Phys. Plasmas 17, 102113 (2010)] immersed in a low pressure plasma. The temporal evolution of these structures can be studied by measuring the transient electron distribution function (EDF). In the present work, transient EDF is measured after formation of a solitary electron hole in nearly uniform, unmagnetized, and collisionless plasma for applied pulse width and, where and are applied pulse width and inverse of ion plasma frequency respectively. Fo...

  8. Reducing spurious gravitational radiation in binary-black-hole simulations by using conformally curved initial data

    E-Print Network [OSTI]

    Geoffrey Lovelace


    At early times in numerical evolutions of binary black holes, current simulations contain an initial burst of spurious gravitational radiation (also called "junk radiation") which is not astrophysically realistic. The spurious radiation is a consequence of how the binary-black-hole initial data are constructed: the initial data are typically assumed to be conformally flat. In this paper, I adopt a curved conformal metric that is a superposition of two boosted, non-spinning black holes that are approximately 15 orbits from merger. I compare junk radiation of the superposed-boosted-Schwarzschild (SBS) initial data with the junk of corresponding conformally flat, maximally sliced (CFMS) initial data. The SBS junk is smaller in amplitude than the CFMS junk, with the junk's leading-order spectral modes typically being reduced by a factor of order two or more.

  9. N = 4 Super-Yang-Mills on Conic Space as Hologram of STU Topological Black Hole

    E-Print Network [OSTI]

    Xing Huang; Yang Zhou


    We construct four-dimensional N=4 super-Yang-Mills theories on a conic sphere with various background R-symmetry gauge fields. We study free energy and supersymmetric Renyi entropy using heat kernel method as well as localization technique. We find that the universal contribution to the partition function in the free field limit is the same as that in the strong coupling limit, which implies that it may be protected by supersymmetry. Based on the fact that, the conic sphere can be conformally mapped to $S^1\\times H^3$ and the R-symmetry background fields can be supported by the R-charges of black hole, we propose that the holographic dual of these theories are five-dimensional, supersymmetric STU topological black holes. We demonstrate perfect agreement between N=4 super-Yang-Mills theories in the planar limit and the STU topological black holes.

  10. Near-Critical Gravitational Collapse and the Initial Mass Function of Primordial Black Holes

    E-Print Network [OSTI]

    J. C. Niemeyer; K. Jedamzik


    The recent discovery of critical phenomena arising in gravitational collapse near the threshold of black hole formation is used to estimate the initial mass function of primordial black holes (PBHs). It is argued that the universal scaling relation between black hole mass and initial perturbation found for a variety of collapsing space-times also applies to PBH formation, indicating the possibility of the formation of PBHs with masses much smaller than one horizon mass. Owing to the natural fine-tuning of initial conditions by the exponential decline of the probability distribution for primordial density fluctuations, sub-horizon mass PBHs are expected to form at all epochs. This result suggests that the constraints on the primordial fluctuation spectrum based on the abundance of PBHs at different mass scales may have to be revisited.

  11. Black Hole spin dependence of general relativistic multi-transonic accretion close to the horizon

    E-Print Network [OSTI]

    Tapas K. Das; Sankhasubhra Nag; Swathi Hegde; Sourav Bhattacharya; Ishita Maity; Bozena Czerny; Paramita Barai; Paul J. Wiita; Vladimir Karas; Tapan Naskar


    We introduce a novel formalism to investigate the role of the spin angular momentum of astrophysical black holes in influencing the behaviour of low angular momentum general relativistic accretion. We propose a metric independent analysis of axisymmetric general relativistic flow, and consequently formulate the space and time dependent equations describing the general relativistic hydrodynamic accretion flow in the Kerr metric. The associated stationary critical solutions for such flow equations are provided and the stability of the stationary transonic configuration is examined using an elegant linear perturbation technique. We examine the properties of infalling material for both prograde and retrograde accretion as a function of the Kerr parameter at extremely close proximity to the event horizon. Our formalism can be used to identify a new spectral signature of black hole spin, and has the potential of performing the black hole shadow imaging corresponding to the low angular momentum accretion flow.

  12. ISCO, Lyapunov exponent and Kolmogorov-Sinai entropy for Kerr-Newman Black hole

    E-Print Network [OSTI]

    Partha Pratim Pradhan


    We compute the principal Lyapunov exponent and Kolmogorov-Sinai(KS) entropy for Kerr-Newman black hole space-times and investigate the stability and instability of the equatorial circular geodesics via these exponents. We also show that the principal Lyapunov exponent and KS entropy can be expressed in terms of the radial equation of ISCO(innermost stable circular orbit) for timelike circular geodesics. The other aspect we have studied that among the all possible circular geodesics, which encircle the central black-hole, the timelike circular geodesics has the longest orbital period i.e. T_{timelike} > T_{photon}, than the null circular geodesics (photon sphere) as measured by asymptotic observers. Thus, the timelike circular geodesics provide the slowest way to circle the Kerr-Newman black-hole. In fact, any stable timelike circular geodesics other than the ISCO traverses more slowly than the null circular geodesics.

  13. Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre

    E-Print Network [OSTI]

    Sheperd Doeleman; Jonathan Weintroub; Alan E. E. Rogers; Richard Plambeck; Robert Freund; Remo P. J. Tilanus; Per Friberg; Lucy M. Ziurys; James M. Moran; Brian Corey; Ken H. Young; Daniel L. Smythe; Michael Titus; Daniel P. Marrone; Roger J. Cappallo; Douglas C. J. Bock; Geoffrey C. Bower; Richard Chamberlin; Gary R. Davis; Thomas P. Krichbaum; James Lamb; Holly Maness; Arthur E. Niell; Alan Roy; Peter Strittmatter; Daniel Werthimer; Alan R. Whitney; David Woody


    The cores of most galaxies are thought to harbour supermassive black holes, which power galactic nuclei by converting the gravitational energy of accreting matter into radiation (ref 1). Sagittarius A*, the compact source of radio, infrared and X-ray emission at the centre of the Milky Way, is the closest example of this phenomenon, with an estimated black hole mass that is 4 million times that of the Sun (refs. 2,3). A long-standing astronomical goal is to resolve structures in the innermost accretion flow surrounding Sgr A* where strong gravitational fields will distort the appearance of radiation emitted near the black hole. Radio observations at wavelengths of 3.5 mm and 7 mm have detected intrinsic structure in Sgr A*, but the spatial resolution of observations at these wavelengths is limited by interstellar scattering (refs. 4-7). Here we report observations at a wavelength of 1.3 mm that set a size of 37 (+16, -10; 3-sigma) microarcseconds on the intrinsic diameter of Sgr A*. This is less than the expected apparent size of the event horizon of the presumed black hole, suggesting that the bulk of SgrA* emission may not be not centred on the black hole, but arises in the surrounding accretion flow.

  14. The characteristic black hole mass resulting from direct collapse in the early universe

    E-Print Network [OSTI]

    Latif, M A; Schmidt, W; Niemeyer, J C


    Black holes of a billion solar masses are observed in the infant universe a few hundred million years after the Big Bang. The direct collapse of protogalactic gas clouds in primordial halos with $\\rm T_{vir} \\geq 10^{4} K$ provides the most promising way to assemble massive black holes. In this study, we aim to determine the characteristic mass scale of seed black holes and the time evolution of the accretion rates resulting from the direct collapse model. We explore the formation of supermassive black holes via cosmological large eddy simulations (LES) by employing sink particles and following their evolution for twenty thousand years after the formation of the first sink. As the resulting protostars were shown to have cool atmospheres in the presence of strong accretion, we assume here that UV feedback is negligible during this calculation. We confirm this result in a comparison run without sinks. Our findings show that black hole seeds with characteristic mass of $\\rm 10^{5} M_{\\odot}$ are formed in the pr...

  15. Black-hole quasinormal resonances: Wave analysis versus a geometric-optics approximation

    SciTech Connect (OSTI)

    Hod, Shahar [Ruppin Academic Center, Emeq Hefer 40250 (Israel) and Hadassah Institute, Jerusalem 91010 (Israel)


    It has long been known that null unstable geodesics are related to the characteristic modes of black holes--the so-called quasinormal resonances. The basic idea is to interpret the free oscillations of a black hole in the eikonal limit in terms of null particles trapped at the unstable circular orbit and slowly leaking out. The real part of the complex quasinormal resonances is related to the angular velocity at the unstable null geodesic. The imaginary part of the resonances is related to the instability time scale (or the inverse Lyapunov exponent) of the orbit. While this geometric-optics description of the black-hole quasinormal resonances in terms of perturbed null rays is very appealing and intuitive, it is still highly important to verify the validity of this approach by directly analyzing the Teukolsky wave equation which governs the dynamics of perturbation waves in the black-hole spacetime. This is the main goal of the present paper. We first use the geometric-optics technique of perturbing a bundle of unstable null rays to calculate the resonances of near-extremal Kerr black holes in the eikonal approximation. We then directly solve the Teukolsky wave equation (supplemented by the appropriate physical boundary conditions) and show that the resultant quasinormal spectrum obtained directly from the wave analysis is in accord with the spectrum obtained from the geometric-optics approximation of perturbed null rays.

  16. X-ray Diffraction and Multi-Frame Phase Contrast Imaging Diagnostics for IMPULSE at the Advanced Photon Source

    SciTech Connect (OSTI)

    Iverson, Adam [National Security Technologies, LLC; Carlson, Carl [National Security Technologies, LLC; Young, Jason [National Security Technologies, LLC; Curtis, Alden [National Security Technologies, LLC; Jensen, Brian [Los Alamos National Laboratory; Ramos, Kyle [Los Alamos National Laboratory; Yeager, John [Los Alamos National Laboratory; Montgomery, David [Los Alamos National Laboratory; Fezza, Kamel [Argonne National Laboratory


    The diagnostic needs of any dynamic loading platform present unique technical challenges that must be addressed in order to accurately measure in situ material properties in an extreme environment. The IMPULSE platform (IMPact system for Ultrafast Synchrotron Experiments) at the Advanced Photon Source (APS) is no exception and, in fact, may be more challenging, as the imaging diagnostics must be synchronized to both the experiment and the 60 ps wide x-ray bunches produced at APS. The technical challenges of time-resolved x-ray diffraction imaging and high-resolution multi-frame phase contrast imaging (PCI) are described in this paper. Example data from recent IMPULSE experiments are shown to illustrate the advances and evolution of these diagnostics with a focus on comparing the performance of two intensified CCD cameras and their suitability for multi-frame PCI. The continued development of these diagnostics is fundamentally important to IMPULSE and many other loading platforms and will benefit future facilities such as the Dynamic Compression Sector at APS and MaRIE at Los Alamos National Laboratory.

  17. Time dependence of Hawking radiation entropy

    SciTech Connect (OSTI)

    Page, Don N., E-mail: [Department of Physics, 4-181 CCIS, University of Alberta, Edmonton, Alberta T6G 2E1 (Canada)


    If a black hole starts in a pure quantum state and evaporates completely by a unitary process, the von Neumann entropy of the Hawking radiation initially increases and then decreases back to zero when the black hole has disappeared. Here numerical results are given for an approximation to the time dependence of the radiation entropy under an assumption of fast scrambling, for large nonrotating black holes that emit essentially only photons and gravitons. The maximum of the von Neumann entropy then occurs after about 53.81% of the evaporation time, when the black hole has lost about 40.25% of its original Bekenstein-Hawking (BH) entropy (an upper bound for its von Neumann entropy) and then has a BH entropy that equals the entropy in the radiation, which is about 59.75% of the original BH entropy 4?M{sub 0}{sup 2}, or about 7.509M{sub 0}{sup 2} ? 6.268 × 10{sup 76}(M{sub 0}/M{sub s}un){sup 2}, using my 1976 calculations that the photon and graviton emission process into empty space gives about 1.4847 times the BH entropy loss of the black hole. Results are also given for black holes in initially impure states. If the black hole starts in a maximally mixed state, the von Neumann entropy of the Hawking radiation increases from zero up to a maximum of about 119.51% of the original BH entropy, or about 15.018M{sub 0}{sup 2} ? 1.254 × 10{sup 77}(M{sub 0}/M{sub s}un){sup 2}, and then decreases back down to 4?M{sub 0}{sup 2} = 1.049 × 10{sup 77}(M{sub 0}/M{sub s}un){sup 2}.

  18. Cold Black Holes in the Harlow-Hayden Approach to Firewalls

    E-Print Network [OSTI]

    Yen Chin Ong; Brett McInnes; Pisin Chen


    Firewalls are controversial principally because they seem to imply departures from general relativistic expectations in regions of spacetime where the curvature need not be particularly large. One of the virtues of the Harlow-Hayden approach to the firewall paradox, concerning the time available for decoding of Hawking radiation emanating from charged AdS black holes, is precisely that it operates in the context of cold black holes, which are not strongly curved outside the event horizon. Here we clarify this point. The approach is based on ideas borrowed from applications of the AdS/CFT correspondence to the quark-gluon plasma. Firewalls aside, our work presents a detailed analysis of the thermodynamics and evolution of evaporating charged AdS black holes with flat event horizons. We show that, in one way or another, these black holes are always eventually destroyed in a time which, while long by normal standards, is short relative to the decoding time of Hawking radiation.

  19. Free motion around black holes with discs or rings: between integrability and chaos - I

    E-Print Network [OSTI]

    O. Semerák; P. Suková


    Geodesic dynamics is regular in the fields of isolated stationary black holes. However, due to the presence of unstable periodic orbits, it easily becomes chaotic under various perturbations. Here we examine what amount of chaoticity is induced in Schwarzschild space-time by a presence of an additional source. Following astrophysical motivation, we specifically consider thin rings or discs lying symmetrically around the hole, and describe the total field in terms of exact static and axially symmetric solutions of Einstein's equations. The growth of chaos in time-like geodesic motion is illustrated on Poincar\\'e sections, on time series of position or velocity and their Fourier spectra, and on time evolution of the orbital `latitudinal action'. The results are discussed in dependence on the mass and position of the ring/disc and on geodesic parameters (energy and angular momentum). In the Introduction, we also add an overview of the literature.

  20. Black Hole Chromosphere at the LHC

    E-Print Network [OSTI]

    Luis Anchordoqui; Haim Goldberg


    If the scale of quantum gravity is near a TeV, black holes will be copiously produced at the LHC. In this work we study the main properties of the light descendants of these black holes. We show that the emitted partons are closely spaced outside the horizon, and hence they do not fragment into hadrons in vacuum but more likely into a kind of quark-gluon plasma. Consequently, the thermal emission occurs far from the horizon, at a temperature characteristic of the QCD scale. We analyze the energy spectrum of the particles emerging from the "chromosphere", and find that the hard hadronic jets are almost entirely suppressed. They are replaced by an isotropic distribution of soft photons and hadrons, with hundreds of particles in the GeV range. This provides a new distinctive signature for black hole events at LHC.

  1. Hole interactions with molecular vibrations on DNA

    E-Print Network [OSTI]

    A. Omerzu; M. Licer; T. Mertelj; V. V. Kabanov; D. Mihailovic


    We report on a study of the interactions between holes and molecular vibrations on dry DNA using photoinduced infrared absorption spectroscopy. Laser photoexcited (PE) holes are found to have a room-temperature lifetime in excess of 1 ms, clearly indicating the presence of localization. However, from a quantitative model analysis of the frequency shifts of vibrational modes caused by the PE holes, we find the holevibrational coupling constant to be relatively small, 0.2. This interaction leads to a change in the conformational energy of 0.015 eV, which is too small to cause selftrapping at room temperature. We conclude that, at least in the dry (A) form, DNA is best understood in terms of a double chain of coupled quantum dots arising from the pseudo-random chain sequence of base pairs, in which Anderson localization prevents the formation of a metallic state.

  2. Neutrino Majorana Mass from Black Hole

    E-Print Network [OSTI]

    Yosuke Uehara


    We propose a new mechanism to generate the neutrino Majorana mass in TeV-scale gravity models. The black hole violates all non-gauged symmetries and can become the origin of lepton number violating processes. The fluctuation of higher-dimensional spacetime can result in the production of a black hole, which emits 2 neutrinos. If neutrinos are Majorana particles, this process is equivalent to the free propagation of a neutrino with the insertion of the black hole. From this fact, we derive the neutrino Majorana mass. The result is completely consistent with the recently observed evidence of neutrinoless double beta decay. And the obtained neutrino Majorana mass satisfies the constraint from the density of the neutrino dark matter, which affects the cosmic structure formation. Furthermore, we can explain the ultrahigh energy cosmic rays by the Z-burst scenario with it.

  3. Particle-hole symmetry parameters for nuclei

    E-Print Network [OSTI]

    Ian Bentley


    Two parameters, nu and zeta, motivated by particle-hole symmetry are introduced. These parameters are determined using the number of proton (or neutron) particles and holes counted from neighboring shell closures. The new parameters can be used to evaluate particle-hole and proton-neutron symmetries of adopted B(E2) values, which indicate that both symmetries are approximate for A>100. The combined symmetries motivate empirical fits of binding energies and the energy ratio E(4_1^+)/E(2_1^+). A global binding energy fit consisting of a traditional liquid droplet and one new shell term, comprised of a function of nu and zeta, reproduces the experimental binding energies of 2353 nuclei with an r.m.s. standard deviation of 1.55 MeV.

  4. Structure of the Spherical Black Hole Interior

    E-Print Network [OSTI]

    A. Bonanno; S. Droz; W. Israel; S. M. Morsink


    The internal structure of a charged spherical black hole is still a topic of debate. In a nonrotating but aspherical gravitational collapse to form a spherical charged black hole, the backscattered gravitational wave tails enter the black hole and are blueshifted at the Cauchy horizon. This has a catastrophic effect if combined with an outflux crossing the Cauchy horizon: a singularity develops at the Cauchy horizon and the effective mass inflates. Recently a numerical study of a massless scalar field in the \\RN background suggested that a spacelike singularity may form before the Cauchy horizon forms. We will show that there exists an approximate analytic solution of the scalar field equations which allows the mass inflation singularity at the Cauchy horizon to exist. In particular, we see no evidence that the Cauchy horizon is preceded by a spacelike singularity.

  5. Gravitational energy of rotating black holes

    E-Print Network [OSTI]

    J. W. Maluf; E. F. Martins; A. Kneip


    In the teleparallel equivalent of general relativity the energy density of asymptotically flat gravitational fields can be naturaly defined as a scalar density restricted to a three-dimensional spacelike hypersurface $\\Sigma$. Integration over the whole $\\Sigma$ yields the standard ADM energy. After establishing the reference space with zero gravitational energy we obtain the expression of the localized energy for a Kerr black hole. The expression of the energy inside a surface of constant radius can be explicitly calculated in the limit of small $a$, the specific angular momentum. Such expression turns out to be exactly the same as the one obtained by means of the method preposed recently by Brown and York. We also calculate the energy contained within the outer horizon of the black hole for {\\it any} value of $a$. The result is practically indistinguishable from $E=2M_{ir}$, where $M_{ir}$ is the irreducible mass of the black hole.

  6. Supplementary Material for The Shape-Time Random Field for Semantic Video Labeling

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    ]. We first describe the inference and learn- ing procedures for the temporal SCRF and STRF models in Section 3. 1. Temporal SCRF 1.1. Inference For the first frame (time t = 1), the SCRF is used for inference, since it does not depend on previous frames. Af- terward, inference in the temporal SCRF

  7. Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel

    E-Print Network [OSTI]

    Cervantes, Joel


    ) transfer on the channel wall by 4.7 to 6.3 times, and increased the pressure drop along the test channel by up to almost 490 times that for fully developed turbulent flow through a smooth channel at the same mass flow rates. The blockages with round holes...

  8. Construction of a Penrose Diagram for a Spatially Coherent Evaporating Black Hole

    E-Print Network [OSTI]

    Beth A. Brown; James Lindesay


    A Penrose diagram is constructed for an example black hole that evaporates at a steady rate as measured by a distant observer, until the mass vanishes, yielding a final state Minkowski space-time. Coordinate dependencies of significant features, such as the horizon and coordinate anomalies, are clearly demonstrated on the diagram. The large-scale causal structure of the space-time is briefly discussed.

  9. On the backward stability of the Schwarzschild black hole singularity

    E-Print Network [OSTI]

    Fournodavlos, Grigorios


    We study the backwards-in-time stability of the Schwarzschild singularity from a dynamical PDE point of view. More precisely, considering a spacelike hypersurface $\\Sigma_0$ in the interior of the black hole region, tangent to the singular hypersurface $\\{r=0\\}$ at a single sphere, we study the problem of perturbing the Schwarzschild data on $\\Sigma_0$ and solving the Einstein vacuum equations backwards in time. We obtain a local well-posedness result for small perturbations lying in certain weighted Sobolev spaces. No symmetry assumptions are imposed. The perturbed spacetimes all have a singularity at a "collapsed" sphere on $\\Sigma_0$, where the leading asymptotics of the curvature and the metric match those of their Schwarzschild counterparts to a suitably high order. As in the Schwarzschild backward evolution, the pinched initial hypersurface $\\Sigma_0$ `opens up' instantly, becoming a smooth spacelike (cylindrical) hypersurface. This result thus yields classes of examples of non-symmetric vacuum spacetim...

  10. Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Don Macune


    The original objective of the project, to deliver an integrated 3 1/8-inch diameter Measurement While Drilling (MWD) and Logging While Drilling (LWD) system for drilling small boreholes using coiled tubing drilling, has been achieved. Two prototype systems have been assembled and tested in the lab. One of the systems has been successfully tested downhole in a conventional rotary drilling environment. Development of the 3 1/8-inch system has also lead to development and commercialization of a slightly larger 3.5-inch diameter system. We are presently filling customer orders for the 3.5-inch system while continuing with commercialization of the 3 1/8-inch system. The equipment developed by this project will be offered for sale to multiple service providers around the world, enabling the more rapid expansion of both coiled tubing drilling and conventional small diameter drilling. The project was based on the reuse of existing technology whenever possible in order to minimize development costs, time, and risks. The project was begun initially by Ultima Labs, at the time a small company ({approx}12 employees) which had successfully developed a number of products for larger oil well service companies. In September, 2006, approximately 20 months after inception of the project, Ultima Labs was acquired by Sondex plc, a worldwide manufacturer of downhole instrumentation for cased hole and drilling applications. The acquisition provided access to proven technology for mud pulse telemetry, downhole directional and natural gamma ray measurements, and surface data acquisition and processing, as well as a global sales and support network. The acquisition accelerated commercialization through existing Sondex customers. Customer demand resulted in changes to the product specification to support hotter (150 C) and deeper drilling (20,000 psi pressure) than originally proposed. The Sondex acquisition resulted in some project delays as the resistivity collar was interfaced to a different MWD system and also as the mechanical design was revised for the new pressure requirements. However, the Sondex acquisition has resulted in a more robust system, secure funding for completion of the project, and more rapid commercialization.

  11. AdS black hole solutions in dilatonic Einstein-Gauss-Bonnet gravity

    SciTech Connect (OSTI)

    Maeda, Kei-ichi [Department of Physics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Advanced Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Ohta, Nobuyoshi [Department of Physics, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan); Sasagawa, Yukinori [Department of Physics, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)


    We find that anti-de Sitter (AdS) spacetime with a nontrivial linear dilaton field is an exact solution in the effective action of the string theory, which is described by gravity with the Gauss-Bonnet curvature terms coupled to a dilaton field in the string frame without a cosmological constant. The AdS radius is determined by the spacetime dimensions and the coupling constants of curvature corrections. We also construct the asymptotically AdS black hole solutions with a linear dilaton field numerically. We find these AdS black holes for hyperbolic topology and in dimensions higher than four. We discuss the thermodynamical properties of those solutions. Extending the model to the case with the even-order higher Lovelock curvature terms, we also find the exact AdS spacetime with a nontrivial dilaton. We further find a cosmological solution with a bounce of three-dimensional space and a solitonic solution with a nontrivial dilaton field, which is regular everywhere and approaches an asymptotically AdS spacetime.

  12. Higher-derivative scalar-vector-tensor theories: black holes, Galileons, singularity cloaking and holography

    E-Print Network [OSTI]

    C. Charmousis; B. Goutéraux; E. Kiritsis


    We consider a general Kaluza-Klein reduction of a truncated Lovelock theory. We find necessary geometric conditions for the reduction to be consistent. The resulting lower-dimensional theory is a higher derivative scalar-tensor theory, depends on a single real parameter and yields second-order field equations. Due to the presence of higher-derivative terms, the theory has multiple applications in modifications of Einstein gravity (Galileon/Horndesky theory) and holography (Einstein-Maxwell-Dilaton theories). We find and analyze charged black hole solutions with planar or curved horizons, both in the 'Einstein' and 'Galileon' frame, with or without cosmological constant. Naked singularities are dressed by a geometric event horizon originating from the higher-derivative terms. The near-horizon region of the near-extremal black hole is unaffected by the presence of the higher derivatives, whether scale invariant or hyperscaling violating. In the latter case, the area law for the entanglement entropy is violated logarithmically, as expected in the presence of a Fermi surface. For negative cosmological constant and planar horizons, thermodynamics and first-order hydrodynamics are derived: the shear viscosity to entropy density ratio does not depend on temperature, as expected from the higher-dimensional scale invariance.

  13. Vacuum polarization for lukewarm black holes

    E-Print Network [OSTI]

    Elizabeth Winstanley; Phil M. Young


    We compute the renormalized expectation value of the square of a quantum scalar field on a Reissner-Nordstrom-de Sitter black hole in which the temperatures of the event and cosmological horizons are equal (`lukewarm' black hole). Our numerical calculations for a thermal state at the same temperature as the two horizons indicate that this renormalized expectation value is regular on both the event and cosmological horizons. We are able to show analytically, using an approximation for the field modes near the horizons, that this is indeed the case.

  14. Vacuum polarization for lukewarm black holes

    SciTech Connect (OSTI)

    Winstanley, Elizabeth; Young, Phil M. [Department of Applied Mathematics, The University of Sheffield, Hicks Building, Hounsfield Road, Sheffield, S3 7RH (United Kingdom)


    We compute the renormalized expectation value of the square of a quantum scalar field on a Reissner-Nordstroem-de Sitter black hole in which the temperatures of the event and cosmological horizons are equal ('lukewarm' black hole). Our numerical calculations for a thermal state at the same temperature as the two horizons indicate that this renormalized expectation value is regular on both the event and cosmological horizons. We are able to show analytically, using an approximation for the field modes near the horizons, that this is indeed the case.

  15. Tachyon Perturbation on Two Dimensional Black Hole

    E-Print Network [OSTI]

    Aniket Basu


    We study the black hole geometry in the presence of tachyonic perturbations, and solve for the form of allowed tachyonic hair in the presence of back reaction, and for the form of the metric under the assumption that only the metric is perturbed but not the dilaton. We evaluate the Kretschmann scalar and argue that the horizon becomes singular in the presence of tachyons, implying that the black hole has turned into a naked singularity. A form of the allowed tachyon potential emerges as a requirement of self-consistency of our solution.

  16. Chaotic Information Processing by Extremal Black Holes

    E-Print Network [OSTI]

    Axenides, Minos; Nicolis, Stam


    We review an explicit regularization of the AdS$_2$/CFT$_1$ correspondence, that preserves all isometries of bulk and boundary degrees of freedom. This scheme is useful to characterize the space of the unitary evolution operators that describe the dynamics of the microstates of extremal black holes in four spacetime dimensions. Using techniques from algebraic number theory to evaluate the transition amplitudes, we remark that the regularization scheme expresses the fast quantum computation capability of black holes as well as its chaotic nature.

  17. Dynamics of galaxy cores and supermassive black holes

    E-Print Network [OSTI]

    David Merritt


    Recent work on the dynamical evolution of galactic nuclei containing supermassive black holes is reviewed. Topics include galaxy structural properties; collisionless and collisional equilibria; loss-cone dynamics; and dynamics of binary and multiple supermassive black holes.

  18. Yield, variance and spatial distribution of electron–hole...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Yield, variance and spatial distribution of electron–hole pairs in CsI. Yield, variance and spatial distribution of electron–hole pairs in CsI. Abstract: A Monte Carlo...

  19. Evaluation of Coso Geothermal Exploratory Hole No. 1 (CGEH-1...

    Open Energy Info (EERE)

    hole with drill cuttings. The second test, on November 2, 1978, utilized a nitrogen-foam-water mixture to clean residual particles from bottom hole, following which nitrogen was...

  20. Topological black holes in Horava-Lifshitz gravity

    SciTech Connect (OSTI)

    Cai Ronggen [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China) and Kavli Institute for Theoretical Physics China (KITPC), Chinese Academy of Sciences, P.O. Box 2735, Beijing 100190 (China); Cao Liming [Asia Pacific Center for Theoretical Physics, Pohang, Gyeongbuk 790-784 (Korea, Republic of); Ohta, Nobuyoshi [Department of Physics, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan)


    We find topological (charged) black holes whose horizon has an arbitrary constant scalar curvature 2k in Horava-Lifshitz theory. Without loss of generality, one may take k=1, 0, and -1. The black hole solution is asymptotically anti-de Sitter with a nonstandard asymptotic behavior. Using the Hamiltonian approach, we define a finite mass associated with the solution. We discuss the thermodynamics of the topological black holes and find that the black hole entropy has a logarithmic term in addition to an area term. We find a duality in Hawking temperature between topological black holes in Horava-Lifshitz theory and Einstein's general relativity: the temperature behaviors of black holes with k=1, 0, and -1 in Horava-Lifshitz theory are, respectively, dual to those of topological black holes with k=-1, 0, and 1 in Einstein's general relativity. The topological black holes in Horava-Lifshitz theory are thermodynamically stable.

  1. Thermal Gradient Holes At Upper Hot Creek Ranch Area (Benoit...

    Open Energy Info (EERE)

    planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300...

  2. A Note on Black Hole Temperature and Entropy

    E-Print Network [OSTI]

    P. R. Silva


    We propose intuitive derivations of the Hawking temperature and the Bekenstein-Hawking entropy of a Schwarzschild black hole.

  3. Entropy of charged dilaton-axion black hole

    E-Print Network [OSTI]

    Tanwi Ghosh; Soumitra SenGupta


    Using brick wall method the entropy of charged dilaton-axion black hole is determined for both asymptotically flat and non-flat cases. The entropy turns out to be proportional to the horizon area of the black hole confirming the Beckenstien, Hawking area-entropy formula for black holes. The leading order logarithmic corrections to the entropy are also derived for such black holes.

  4. Can the fluctuations of a black hole be treated thermodynamically?

    E-Print Network [OSTI]

    Kostyantyn Ropotenko


    Since the temperature of a typical Schwarzschild black hole is very low, some doubts are raised about whether the fluctuations of the black hole can be treated thermodynamically. It is shown that this is not the case: the thermodynamic fluctuations of a black hole are considerably larger than the corresponding quantum fluctuations. Moreover the ratio of the mean square thermodynamic fluctuation to the corresponding quantum fluctuation can be interpreted as a number of the effective constituents of a black hole.

  5. Black holes in Born-Infeld extended new massive gravity

    SciTech Connect (OSTI)

    Ghodsi, Ahmad; Yekta, Davood Mahdavian [Department of Physics, Ferdowsi University of Mashhad, P.O. Box 1436, Mashhad (Iran, Islamic Republic of)


    In this paper we find different types of black holes for the Born-Infeld extended new massive gravity. Our solutions include (un)charged warped (anti-)de Sitter black holes for four and six derivative expanded action. We also look at the black holes in unexpanded Born-Infeld action. In each case we calculate the entropy, angular momentum and mass of the black holes. We also find the central charges for the conformal field theory duals.

  6. Entropy and Area of Black Holes in Loop Quantum Gravity

    E-Print Network [OSTI]

    I. B. Khriplovich


    Simple arguments related to the entropy of black holes strongly constrain the spectrum of the area operator for a Schwarzschild black hole in loop quantum gravity. In particular, this spectrum is fixed completely by the assumption that the black hole entropy is maximum. Within the approach discussed, one arrives in loop quantum gravity at a quantization rule with integer quantum numbers $n$ for the entropy and area of a black hole.

  7. Accretion onto Supermassive Black Holes in Quasars: Learning from Optical/UV Observations

    E-Print Network [OSTI]

    Paola Marziani; Deborah Dultzin-Hacyan; Jack W. Sulentic


    Accretion processes in quasars and active galactic nuclei are still poorly understood, especially as far as the connection between observed spectral properties and physical parameters is concerned. Quasars show an additional degree of complexity compared to stars that is related to anisotropic emission/obscuration influencing the observed properties in most spectral ranges. This complicating factor has hampered efforts to define the equivalent of an Hertzsprung-Russel diagram for quasars. Even if it has recently become possible to estimate black hole mass and Eddington ratio for sources using optical and UV broad emission lines, the results are still plagued by large uncertainties. Nevertheless, robust trends are emerging from multivariate analysis of large spectral datasets of quasars. A firm observational basis is being laid out by accurate measurements of broad emission line properties especially when the source rest-frame is known. We consider the most widely discussed correlations (i.e. the so-called "eigenvector 1 parameter space" and the "Baldwin effect") and analyze how they can be explained in terms of accretion properties, broad line region structure, and source evolution. We critically review recent estimates of black hole mass, accretion rate, spin and possible orientation indicators, stressing that any improvement in these parameters will provide a much better understanding of the physics and dynamics of the region producing the optical and UV broad emission lines. More accurate measurements of Eddington ratio and black hole mass may have a significant impact on our ideas about evolution of quasar properties with redshift and luminosity as well as on broader cosmological issues.

  8. ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes

    E-Print Network [OSTI]

    Iliffe, Thomas M.

    ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes: initial discoveries from+Business Media B.V. 2011 Abstract Inland blue holes of the Bahamas are anchialine ecosystems with distinct fresh and geomicrobiology exploration of blue holes are providing a first glimpse of the geochemistry and microbial life

  9. Einstein Algebras and the Hole Argument JONATHAN BAIN

    E-Print Network [OSTI]

    Aronov, Boris

    1 Einstein Algebras and the Hole Argument JONATHAN BAIN Department of Humanities and word count: 5498 #12;2 word count: 5498 Einstein Algebras and the Hole Argument ABSTRACT. Einstein. In particular, I suggest that a gauge-invariant interpretation of Einstein algebras that avoids the hole


    E-Print Network [OSTI]

    Westervelt, R.M.



  11. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson


    Primordial stars are likely to be very massive $\\geq30\\Msun$, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos in the mass range $10^{6}-10^{10}\\Ms$. Such early black holes, at redshifts z$\\gtsim10$, could be the seed black holes for the many supermassive black holes found in galaxies in the local universe. If they exist, their mergers with nearby supermassive black holes may be a prime signal for long wavelength gravitational wave detectors. We simulate formation of black holes in the center of high redshift dark matter halos and explore implications of initial natal kick velocities conjectured by some formation models. The central concentration of early black holes in present day galaxies is reduced if they are born even with moderate kicks of tens of km/s. The modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the lower mass black holes as compared to those still embedded in their parent halos. Therefore, merger rates may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N--body simulations we quantify the role of natal kicks of black holes formed from massive metal free stars on their merger rates with supermassive black holes in present day galaxies. Our results also apply to black holes ejected by the gravitational slingshot mechanism.

  12. Thermal Impact of Fasteners in High-Performance Wood-Framed Walls: Preprint

    SciTech Connect (OSTI)

    Christensen, D.


    Buildings are heavy consumers of energy, and residential building design is rapidly addressing topics to maximize energy conservation en route to net-zero energy consumption. Annual energy analysis of a building informs the choice among disparate energy measures, for cost, durability, occupant comfort, and whole-house energy use. Physics-based and empirical models of elements of a building are used in such analyses. High-performance wood-framed walls enable builders to construct homes that use much less than 40% of the energy consumed by similar homes built to minimum code. Modeling for these walls has considered physical features such as framing factor, insulation and framing properties, roughness and convective effects, and air leakage. The thermal effects of fasteners used to construct these walls have not been fully evaluated, even though their thermal conductivity is orders of magnitudes higher than that of other building materials. Drywall screws and siding nails are considered in this finite element thermal conductivity analysis of wall sections that represent wood-framed walls that are often used in high-performance homes. Nails and screws reduce even the best walls' insulating performance by approximately 3% and become increasingly significant as the framing factor increases.

  13. Quasilinear Carbon Transport In An Impurity Hole Plasma In LHD

    SciTech Connect (OSTI)

    Mikkelsen, David R. [PPPL; Tanaka, K. [NIFS; Nunami, M. [NIFS; Watanabe, T-H. [Nagoya University; Sugama, H. [NIFS; Yoshinuma, M. [NIFS; Suzuki, Y. [NIFS; Goto, M. [NIFS; Morita, S. [NIFS; Wieland, B. [NIFS; Yamada, I. [NIFS; Yashura, R. [NIFS; Akiyama, T. [NIFS; Pablant, Novimir A. [PPPL


    Comprehensive electrostatic gyrokinetic linear stability calculations for ion-scale microinstabilities in an LHD plasma with an ion-ITB and carbon "impurity hole" are used to make quasilinear estimates of particle flux to explore whether microturbulence can explain the observed outward carbon fluxes that flow "up" the impurity density gradient. The ion temperature is not stationary in the ion-ITB phase of the simulated discharge, during which the core carbon density decreases continuously. To fully sample these varying conditions the calculations are carried out at three radial locations and four times. The plasma parameter inputs are based on experimentally measured profiles of electron and ion temperature, as well as electron and carbon density. The spectroscopic line-average ratio of hydrogen and helium densities is used to set the density of these species. Three ion species (H,He,C) and the electrons are treated kinetically, including collisions. Electron instability drive does enhance the growth rate significantly, but the most unstable modes have characteristics of ion temperature gradient (ITG) modes in all cases. As the carbon density gradient is scanned between the measured value and zero, the quasilinear carbon flux is invariably inward when the carbon density profile is hollow, so turbulent transport due to the instabilities considered here does not explain the observed outward flux of impurities in impurity hole plasmas. The stiffness of the quasilinear ion heat flux is found to be 1.7-2.3, which is lower than several estimates in tokamaks.

  14. String-theoretic breakdown of effective field theory near black hole horizons

    E-Print Network [OSTI]

    Matthew Dodelson; Eva Silverstein


    We investigate the validity of the equivalence principle near horizons in string theory, analyzing the breakdown of effective field theory caused by longitudinal string spreading effects. An experiment is set up where a detector is thrown into a black hole a long time after an early infalling string. Light cone gauge calculations, taken at face value, indicate a detectable level of root-mean-square longitudinal spreading of the initial string as measured by the late infaller. This results from the large relative boost between the string and detector in the near horizon region, which develops automatically despite their modest initial energies outside the black hole and the weak curvature in the geometry. We subject this scenario to basic consistency checks, using these to obtain a relatively conservative criterion for its detectability. In a companion paper, we exhibit longitudinal nonlocality in well-defined gauge-invariant S-matrix calculations, obtaining results consistent with the predicted spreading albeit not in a direct analogue of the black hole process. We discuss applications of this effect to the firewall paradox, and estimate the time and distance scales it predicts for new physics near black hole and cosmological horizons.

  15. Remote down-hole well telemetry

    DOE Patents [OSTI]

    Briles, Scott D. (Los Alamos, NM); Neagley, Daniel L. (Albuquerque, NM); Coates, Don M. (Santa Fe, NM); Freund, Samuel M. (Los Alamos, NM)


    The present invention includes an apparatus and method for telemetry communication with oil-well monitoring and recording instruments located in the vicinity of the bottom of gas or oil recovery pipes. Such instruments are currently monitored using electrical cabling that is inserted into the pipes; cabling has a short life in this environment, and requires periodic replacement with the concomitant, costly shutdown of the well. Modulated reflectance, a wireless communication method that does not require signal transmission power from the telemetry package will provide a long-lived and reliable way to monitor down-hole conditions. Normal wireless technology is not practical since batteries and capacitors have to frequently be replaced or recharged, again with the well being removed from service. RF energy generated above ground can also be received, converted and stored down-hole without the use of wires, for actuating down-hole valves, as one example. Although modulated reflectance reduces or eliminates the loss of energy at the sensor package because energy is not consumed, during the transmission process, additional stored extra energy down-hole is needed.

  16. Limits on New Physics from Black Holes

    E-Print Network [OSTI]

    Clifford Cheung; Stefan Leichenauer


    Black holes emit high energy particles which induce a finite density potential for any scalar field $\\phi$ coupling to the emitted quanta. Due to energetic considerations, $\\phi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\\phi$ resides at a metastable minimum, this effect can drive $\\phi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\\phi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

  17. Black hole formation in the early universe

    E-Print Network [OSTI]

    Latif, M A; Schmidt, W; Niemeyer, J


    Supermassive black holes with up to a $\\rm 10^{9}~M_{\\odot}$ dwell in the centers of present-day galaxies, and their presence has been confirmed at z $\\geq$ 6. Their formation at such early epochs is still an enigma. Different pathways have been suggested to assemble supermassive black holes in the first billion years after the Big Bang. Direct collapse has emerged as a highly plausible scenario to form black holes as it provides seed masses of $\\rm 10^{5}-10^{6}~M_{\\odot}$. Gravitational collapse in atomic cooling haloes with virial temperatures T$_{vir} \\geq 10^{4}$~K may lead to the formation of massive seed black holes in the presence of an intense background UV flux. Turbulence plays a central role in regulating accretion and transporting angular momentum. We present here the highest resolution cosmological large-eddy simulations to date which track the evolution of high-density regions on scales of $0.25$~AU beyond the formation of the first peak, and study the impact of subgrid-scale turbulence. The pe...

  18. Vector particles tunneling from BTZ black holes

    E-Print Network [OSTI]

    Ge-Rui Chen; Shiwei Zhou; Yong-Chang Huang


    In this paper we investigate vector particles' Hawking radiation from a BTZ black hole. By applying the WKB approximation and the Hamilton-Jacobi Ansatz to the Proca equation, we obtain the tunneling spectrum of vector particles. The expected Hawking temperature is recovered.

  19. Brief review on higher spin black holes

    E-Print Network [OSTI]

    Alfredo Perez; David Tempo; Ricardo Troncoso


    We review some relevant results in the context of higher spin black holes in three-dimensional spacetimes, focusing on their asymptotic behaviour and thermodynamic properties. For simplicity, we mainly discuss the case of gravity nonminimally coupled to spin-3 fields, being nonperturbatively described by a Chern-Simons theory of two independent sl(3,R) gauge fields. Since the analysis is particularly transparent in the Hamiltonian formalism, we provide a concise discussion of their basic aspects in this context; and as a warming up exercise, we briefly analyze the asymptotic behaviour of pure gravity, as well as the BTZ black hole and its thermodynamics, exclusively in terms of gauge fields. The discussion is then extended to the case of black holes endowed with higher spin fields, briefly signaling the agreements and discrepancies found through different approaches. We conclude explaining how the puzzles become resolved once the fall off of the fields is precisely specified and extended to include chemical potentials, in a way that it is compatible with the asymptotic symmetries. Hence, the global charges become completely identified in an unambiguous way, so that different sets of asymptotic conditions turn out to contain inequivalent classes of black hole solutions being characterized by a different set of global charges.

  20. Deep-hole drilling Fruit Flies & Zebrafish

    E-Print Network [OSTI]

    Li, Yi

    surface to purify air, employing existing technology in a new way. It is the brainchild of artistFEATURE Deep-hole drilling Fruit Flies & Zebrafish Björk FEATURE Academics & Industry: ResearchIScOvER mAGAZInE Research and Innovation Services University of Sheffield New

  1. The river model of black holes

    E-Print Network [OSTI]

    Andrew J. S. Hamilton; Jason P. Lisle


    This paper presents an under-appreciated way to conceptualize stationary black holes, which we call the river model. The river model is mathematically sound, yet simple enough that the basic picture can be understood by non-experts. %that can by understood by non-experts. In the river model, space itself flows like a river through a flat background, while objects move through the river according to the rules of special relativity. In a spherical black hole, the river of space falls into the black hole at the Newtonian escape velocity, hitting the speed of light at the horizon. Inside the horizon, the river flows inward faster than light, carrying everything with it. We show that the river model works also for rotating (Kerr-Newman) black holes, though with a surprising twist. As in the spherical case, the river of space can be regarded as moving through a flat background. However, the river does not spiral inward, as one might have anticipated, but rather falls inward with no azimuthal swirl at all. Instead, the river has at each point not only a velocity but also a rotation, or twist. That is, the river has a Lorentz structure, characterized by six numbers (velocity and rotation), not just three (velocity). As an object moves through the river, it changes its velocity and rotation in response to tidal changes in the velocity and twist of the river along its path. An explicit expression is given for the river field, a six-component bivector field that encodes the velocity and twist of the river at each point, and that encapsulates all the properties of a stationary rotating black hole.

  2. Sowing the seeds of massive black holes in small galaxies: Young clusters as the building blocks of ultracompact dwarf galaxies

    SciTech Connect (OSTI)

    Amaro-Seoane, Pau [Max Planck Institut für Gravitationsphysik (Albert-Einstein-Institut), D-14476 Potsdam (Germany); Konstantinidis, Symeon [Astronomisches Rechen-Institut, Zentrum für Astronomie, Universität Heidelberg, Mönchhofstraße 12-14, Heidelberg D-69120 (Germany); Freitag, Marc Dewi [Institute of Astronomy, Madingley Road, CB3 0HA Cambridge (United Kingdom); Coleman Miller, M. [Department of Astronomy and Joint Space-Science Institute, University of Maryland, College Park, MD 20742-2421 (United States); Rasio, Frederic A., E-mail:, E-mail:, E-mail:, E-mail:, E-mail: [Department of Physics and Astronomy, and Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Northwestern University, Evanston, IL 60208 (United States)


    Interacting galaxies often have complexes of hundreds of young stellar clusters of individual masses ?10{sup 4}-10{sup 6} M {sub ?} in regions that are a few hundred parsecs across. These cluster complexes interact dynamically, and their coalescence is a candidate for the origin of some ultracompact dwarf galaxies. Individual clusters with short relaxation times are candidates for the production of intermediate-mass black holes of a few hundred solar masses, via runaway stellar collisions prior to the first supernovae in a cluster. It is therefore possible that a cluster complex hosts multiple intermediate-mass black holes that may be ejected from their individual clusters due to mergers or binary processes, but bound to the complex as a whole. Here we explore the dynamical interaction between initially free-flying massive black holes and clusters in an evolving cluster complex. We find that, after hitting some clusters, it is plausible that the massive black hole will be captured in an ultracompact dwarf forming near the center of the complex. In the process, the hole typically triggers electromagnetic flares via stellar disruptions, and is also likely to be a prominent source of gravitational radiation for the advanced ground-based detectors LIGO and VIRGO. We also discuss other implications of this scenario, notably that the central black hole could be considerably larger than expected in other formation scenarios for ultracompact dwarfs.

  3. Comparison of the Window-Frame RHIC-abort kicker with C-type Kicker

    SciTech Connect (OSTI)

    Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Hahn, H. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Meng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.; Severance, Michael [Stony Brook Univ., NY (United States); McMahan, Brandon [Westhampton High School, NY (United States)


    The high intensity proton bunches (~2.5x1011 p/bunch ) circulating in RHIC increase the temperature of the ferrite-made RHIC-abort-kickers above the Curie point, as a result the kickers cannot provide the required field to abort the beam at the beam dump. A team of experts in the CAD department worked on modifying the design of the window-frame RHIC-abort kicker to minimize the hysteresis losses responsible for the increase of the ferrite’s temperature. In this technical note we report some results from the study of two possible modifications of the window-frame RHIC-abort kicker and we compare these results with those of a propose C-type RHIC-abort kicker. We also include an Appendix where we describe a method which may further reduce the hysteresis losses of the window-frame kicker.

  4. Degradation of a quantum directional reference frame as a random walk

    E-Print Network [OSTI]

    Stephen D. Bartlett; Terry Rudolph; Barry C. Sanders; Peter S. Turner


    We investigate if the degradation of a quantum directional reference frame through repeated use can be modeled as a classical direction undergoing a random walk on a sphere. We demonstrate that the behaviour of the fidelity for a degrading quantum directional reference frame, defined as the average probability of correctly determining the orientation of a test system, can be fit precisely using such a model. Physically, the mechanism for the random walk is the uncontrollable back-action on the reference frame due to its use in a measurement of the direction of another system. However, we find that the magnitude of the step size of this random walk is not given by our classical model and must be determined from the full quantum description.

  5. Improved methods for simulating nearly extremal binary black holes

    E-Print Network [OSTI]

    Mark A. Scheel; Matthew Giesler; Daniel A. Hemberger; Geoffrey Lovelace; Kevin Kuper; Michael Boyle; Bela Szilagyi; Lawrence E. Kidder


    Astrophysical black holes could be nearly extremal (that is, rotating nearly as fast as possible); therefore, nearly extremal black holes could be among the binaries that current and future gravitational-wave observatories will detect. Predicting the gravitational waves emitted by merging black holes requires numerical-relativity simulations, but these simulations are especially challenging when one or both holes have mass $m$ and spin $S$ exceeding the Bowen-York limit of $S/m^2=0.93$. We present improved methods that enable us to simulate merging, nearly extremal black holes more robustly and more efficiently. We use these methods to simulate an unequal-mass, precessing binary black hole coalescence, where the larger black hole has $S/m^2=0.99$. We also use these methods to simulate a non-precessing binary black hole coalescence, where both black holes have $S/m^2=0.994$, nearly reaching the Novikov-Thorne upper bound for holes spun up by thin accretion disks. We demonstrate numerical convergence and estimate the numerical errors of the waveforms; we compare numerical waveforms from our simulations with post-Newtonian and effective-one-body waveforms; we compare the evolution of the black-hole masses and spins with analytic predictions; and we explore the effect of increasing spin magnitude on the orbital dynamics (the so-called "orbital hangup" effect).

  6. Particle rapidity distribution in proton-nucleus collisions using the proton-contributor reference frame

    E-Print Network [OSTI]

    Gines Martinez-Garcia


    I define the proton-contributor reference frame in proton nucleus (p--A) collisions as the center of mass of the system formed by the proton and the participant nucleons of the nucleus. Assuming that the rapidity distribution of produced particles is symmetric in the proton-contributor reference frame, several measurements in p-Pb collisions at $\\sqrt{s_{\\rm NN}} = 5.02 {\\rm TeV}$ can be described qualitatively. These include rapidity distributions of charged particles, $J/\\psi$ and Z bosons.

  7. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    DOE Patents [OSTI]

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki


    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency a laboratory frame. The Fourier-encoded NMR signal is detected.

  8. Acoustic clouds: standing sound waves around a black hole analogue

    E-Print Network [OSTI]

    Carolina L. Benone; Luis C. B. Crispino; Carlos Herdeiro; Eugen Radu


    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  9. Acoustic clouds: standing sound waves around a black hole analogue

    E-Print Network [OSTI]

    Benone, Carolina L; Herdeiro, Carlos; Radu, Eugen


    Under certain conditions sound waves in fluids experience an acoustic horizon with analogue properties to those of a black hole event horizon. In particular, a draining bathtub-like model can give rise to a rotating acoustic horizon and hence a rotating black hole (acoustic) analogue. We show that sound waves, when enclosed in a cylindrical cavity, can form stationary waves around such rotating acoustic black holes. These acoustic perturbations display similar properties to the scalar clouds that have been studied around Kerr and Kerr-Newman black holes; thus they are dubbed acoustic clouds. We make the comparison between scalar clouds around Kerr black holes and acoustic clouds around the draining bathtub explicit by studying also the properties of scalar clouds around Kerr black holes enclosed in a cavity. Acoustic clouds suggest the possibility of testing, experimentally, the existence and properties of black hole clouds, using analog models.

  10. The Role of Primordial Kicks on Black Hole Merger Rates

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson


    Primordial stars are likely to be very massive >30 Msun, form in isolation, and will likely leave black holes as remnants in the centers of their host dark matter halos. We expect primordial stars to form in halos in the mass range 10^6-10^10 Msun. Some of these early black holes, formed at redshifts z>10, could be the seed black hole for a significant fraction of the supermassive black holes found in galaxies in the local universe. If the black hole descendants of the primordial stars exist, their mergers with nearby supermassive black holes may be a prime candidate for long wavelength gravitational wave detectors. We simulate formation and evolution of dark matter halos in LambdaCDM universe. We seed high-redshift dark matter halos with early black holes, and explore the merger history of the host halos and the implications of black hole's kick velocities arising from their coalescence. The central concentration of low mass early black holes in present day galaxies is reduced if they experience even moderate kicks of tens of km/s. Even such modest kicks allow the black holes to leave their parent halo, which consequently leads to dynamical friction being less effective on the low mass black holes that were ejected, compared to those still embedded in their parent halos. Therefore, merger rates with central supermassive black holes in the largest halos may be reduced by more than an order of magnitude. Using analytical and illustrative cosmological N-body simulations, we quantify the role of kicks on the merger rates of black holes formed from massive metal free stars with supermassive black holes in present day galaxies.

  11. Peeping at chaos: Nondestructive monitoring of chaotic systems by measuring long-time escape rates

    E-Print Network [OSTI]

    L. A. Bunimovich; C. P. Dettmann


    One or more small holes provide non-destructive windows to observe corresponding closed systems, for example by measuring long time escape rates of particles as a function of hole sizes and positions. To leading order the escape rate of chaotic systems is proportional to the hole size and independent of position. Here we give exact formulas for the subsequent terms, as sums of correlation functions; these depend on hole size and position, hence yield information on the closed system dynamics. Conversely, the theory can be readily applied to experimental design, for example to control escape rates.

  12. Building America Webinar: High-Performance Enclosure Strategies, Part I: Unvented Roof Systems and Innovative Advanced Framing Strategies

    Broader source: [DOE]

    This presentation was delivered at the February 12, 2015, Building America webinar, High-Performance Enclosure Strategies, Part I: Unvented Roof Systems and Innovative Advanced Framing Strategies.

  13. Relativistic simulations of black hole-neutron star coalescence: the jet emerges

    E-Print Network [OSTI]

    Vasileios Paschalidis; Milton Ruiz; Stuart L. Shapiro


    We perform magnetohydrodynamic simulations in full general relativity (GRMHD) of a binary black hole--neutron star on a quasicircular orbit that undergoes merger. The binary mass ratio is $3:1$, the black hole has initial spin parameter $a/m=0.75$ ($m$ is the black hole Christodoulou mass) aligned with the orbital angular momentum, and the neutron star is an irrotational $\\Gamma=2$ polytrope. We adopt a $\\Gamma$-law equation of state. About two orbits prior to merger (at time $t=t_B$), we seed the neutron star with a dynamically weak interior dipole magnetic field that extends into the stellar exterior. At $t=t_B$ the exterior has a low density atmosphere with constant plasma parameter $\\beta\\equiv P_{\\rm gas}/P_{\\rm mag}$. Varying $\\beta$ at $t_B$ in the exterior from $0.1$ to $0.01$, we find that at a time $\\sim 4000{\\rm M} \\sim 100(M_{\\rm NS}/1.4M_\\odot)$ms [M is the total (ADM) mass] following the onset of accretion of tidally disrupted debris, magnetic winding above the remnant black hole poles builds up the magnetic field sufficiently to launch a mildly relativistic, collimated outflow - an incipient jet. The duration of the accretion and the lifetime of the jet is $\\Delta t\\sim 0.5(M_{\\rm NS}/1.4M_\\odot)$s. Our simulations furnish the first explicit examples in GRMHD which show that a jet can emerge following a black hole - neutron star merger.

  14. Relativistic simulations of black hole-neutron star coalescence: the jet emerges

    E-Print Network [OSTI]

    Vasileios Paschalidis; Milton Ruiz; Stuart L. Shapiro


    We perform magnetohydrodynamic simulations in full general relativity (GRMHD) of a binary black hole-neutron star on a quasicircular orbit that undergoes merger. The binary mass ratio is 3:1, the black hole initial spin parameter $a/m=0.75$ ($m$ is the black hole Christodoulou mass) aligned with the orbital angular momentum, and the neutron star is an irrotational $\\Gamma=2$ polytrope. About two orbits prior to merger (at time $t=t_B$), we seed the neutron star with a dynamically weak interior dipole magnetic field that extends into the stellar exterior. At $t=t_B$ the exterior has a low-density atmosphere with constant plasma parameter $\\beta\\equiv P_{\\rm gas}/P_{\\rm mag}$. Varying $\\beta$ at $t_B$ in the exterior from $0.1$ to $0.01$, we find that at a time $\\sim 4000{\\rm M} \\sim 100(M_{\\rm NS}/1.4M_\\odot)$ms [M is the total (ADM) mass] following the onset of accretion of tidally disrupted debris, magnetic winding above the remnant black hole poles builds up the magnetic field sufficiently to launch a mildly relativistic, collimated outflow - an incipient jet. The duration of the accretion and the lifetime of the jet is $\\Delta t\\sim 0.5(M_{\\rm NS}/1.4M_\\odot)$s. Our simulations furnish the first explicit examples in GRMHD which show that a jet can emerge following a black hole - neutron star merger.

  15. Laser stabilization using spectral hole burning

    E-Print Network [OSTI]

    L. Rippe; B. Julsgaard; A. Walther; S. Kröll


    We have frequency stabilized a Coherent CR699-21 dye laser to a transient spectral hole on the 606 nm transition in Pr^{+3}:Y_2SiO_5. A frequency stability of 1 kHz has been obtained on the 10 microsecond timescale together with a long-term frequency drift below 1 kHz/s. RF magnetic fields are used to repopulate the hyperfine levels allowing us to control the dynamics of the spectral hole. A detailed theory of the atomic response to laser frequency errors has been developed which allows us to design and optimize the laser stabilization feedback loop, and specifically we give a stability criterion that must be fulfilled in order to obtain very low drift rates. The laser stability is sufficient for performing quantum gate experiments in Pr^{+3}:Y_2SiO_5.

  16. Geometric description of BTZ black holes thermodynamics

    E-Print Network [OSTI]

    Hernando Quevedo; Alberto Sanchez


    We study the properties of the space of thermodynamic equilibrium states of the Ba\\~nados-Teitelboim-Zanelli (BTZ) black hole in (2+1)-gravity. We use the formalism of geometrothermodynamics to introduce in the space of equilibrium states a $2-$dimensional thermodynamic metric whose curvature is non-vanishing, indicating the presence of thermodynamic interaction, and free of singularities, indicating the absence of phase transitions. Similar results are obtained for generalizations of the BTZ black hole which include a Chern-Simons term and a dilatonic field. Small logarithmic corrections of the entropy turn out to be represented by small corrections of the thermodynamic curvature, reinforcing the idea that thermodynamic curvature is a measure of thermodynamic interaction.

  17. The hydraulic jump as a white hole

    E-Print Network [OSTI]

    G. E. Volovik


    In the geometry of the circular hydraulic jump, the velocity of the liquid in the interior region exceeds the speed of capillary-gravity waves (ripplons), whose spectrum is `relativistic' in the shallow water limit. The velocity flow is radial and outward, and thus the relativistic ripplons cannot propagating into the interior region. In terms of the effective 2+1 dimensional Painleve-Gullstrand metric appropriate for the propagating ripplons, the interior region imitates the white hole. The hydraulic jump represents the physical singularity at the white-hole horizon. The instability of the vacuum in the ergoregion inside the circular hydraulic jump and its observation in recent experiments on superfluid 4He by E. Rolley, C. Guthmann, M.S. Pettersen and C. Chevallier in physics/0508200 are discussed.

  18. Slant hole completion test. Final report

    SciTech Connect (OSTI)

    Mann, R.L.


    One of the Department of Energy`s (DOE) Strategies and Objectives in the Natural Gas Program is to conduct activities to transfer technology from R&D programs to potential users. The Slant Hole Completion Test has achieved exactly this objective. The Slant Hole site is essentially the same as the Multiwell site and is located in the southeastern portion of the Piceance Basin near Rifle, Colorado. The Piceance Basin is typical of the Western low permeability basins that contain thick sequences of sands, silts and coals deposited during the Cretaceous period. These sequences contain vast amounts of natural gas but have proven to be resistant to commercial production because of the low permeability of the host rocks. Using the knowledge gained from the DOE`s earlier Multiwell experiment, the SHCT-1 was drilled to demonstrate that by intersecting the natural fractures found in these ``tight rocks,`` commercial gas production can be obtained.

  19. Phase Structure of Higher Spin Black Holes

    E-Print Network [OSTI]

    Abhishek Chowdhury; Arunabha Saha


    We revisit the study of the phase structure of higher spin black holes carried out in arXiv$:1210.0284$ using the "canonical formalism". In particular we study the low as well as high temperature regimes. We show that the Hawking-Page transition takes place in the low temperature regime. The thermodynamically favoured phase changes from conical surplus to black holes and then again to conical surplus as we increase temperature. We then show that in the high temperature regime the diagonal embedding gives the appropriate description. We also give a map between the parameters of the theory near the IR and UV fixed points. This makes the "good" solutions near one end map to the "bad" solutions near the other end and vice versa.

  20. Quantized black holes, their spectrum and radiation

    SciTech Connect (OSTI)

    Khriplovich, I. B. [Budker Institute of Nuclear Physics (Russian Federation)], E-mail:


    Under quite natural general assumptions, the following results are obtained. The maximum entropy of a quantized surface is demonstrated to be proportional to the surface area in the classical limit. The general structure of the horizon spectrum is found. In the special case of loop quantum gravity, the value of the Barbero-Immirzi parameter is found. The discrete spectrum of thermal radiation of a black hole fits the Wien profile. The natural widths of the lines are much smaller than the distances between them. The total intensity of the thermal radiation is estimated. If the density of quantized primordial black holes is close to the present upper limit on the dark-matter density in our Solar system, the sensitivity of modern detectors is close to that necessary for detecting this radiation.

  1. Framing the Conversation: The Role of Facebook Conversations in Shopping for Eyeglasses

    E-Print Network [OSTI]

    Kane, Shaun K.

    Framing the Conversation: The Role of Facebook Conversations in Shopping for Eyeglasses Karim Said Warby Parker's Facebook page and explore the ways customers formulate questions and conversations,000 Facebook posts, consisting of photos, comments, and "likes". Using statistical analyses and qualitative

  2. Frame-Rate Spatial Referencing Based on Invariant Indexing and Alignment with

    E-Print Network [OSTI]

    Lin, Gang

    (such as a laser) pointed at the human retina, from a series of image frames. We treat the problem in the US alone [13], [24], [25], [32], but still has only a 50 percent success rate. A major cause of the energy delivered anywhere on the retina, and there are no automatic alarms or safety shut-offs when

  3. G-Structures Local Equivalence and Classification of Co-frames

    E-Print Network [OSTI]

    Patrick, George

    Motivation G-Structures Local Equivalence and Classification of Co-frames Solution Summary and Further Results Local Equivalence and Classification of Finite Type G-Structures Ivan Struchiner1 1 and Infinite Dimensional Ivan Struchiner Equivalence of G-Structures #12;Motivation G-Structures Local

  4. The equivalence principle and the relative velocity of local inertial frames

    E-Print Network [OSTI]

    F. Shojai; A. Shojai


    In this paper we explicitly show that in general relativity, the relative velocity of two local inertial frames is always less than the velocity of light. This fact is a by-product of the equivalence principle. The general result is then illustrated within two examples, the FLRW cosmological model and the Schwarzschild metric.

  5. A Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry

    E-Print Network [OSTI]

    Gerstein, Mark

    uncertainties in this data set closely match numerical values reported in the recent survey of nucleic acid baseA Standard Reference Frame for the Description of Nucleic Acid Base-pair Geometry These preliminary (Rockefeller University), Richard E. Dickerson (University of California, Los Angeles), Mark Gerstein (Yale

  6. Contamination models in the R package simFrame for statistical simulation

    E-Print Network [OSTI]

    Filzmoser, Peter

    Contamination models in the R package simFrame for statistical simulation A. Alfons1 , M. Templ1 emphasis on applications in robust statistics. Contamination is thereby modeled as a two-step process. Furthermore, the existing framework may be extended with user-defined contamination models. 1 Introduction

  7. Developing Low-Conductance Window Frames: Capabilities and Limitations of Current Window Heat Transfer Design Tools

    E-Print Network [OSTI]

    Transfer Design Tools Arild Gustavsen1,* , Dariush Arasteh2 , Bjørn Petter Jelle3,4 , Charlie Curcija5-conductance window frames requires accurate simulation tools for product research and development. Based and develop recommendation for inclusion into the design fenestration tools. 3. Assess existing correlations

  8. Intrinsic wavelet and frame applications John J. Benedetto and Travis D. Andrews

    E-Print Network [OSTI]

    Benedetto, John J.

    Intrinsic wavelet and frame applications John J. Benedetto and Travis D. Andrews Norbert Wiener wavelet applications, by which we mean mathematical modeling of a physical phe- nomenon in which wavelet as the invaluable use of dyadic wavelets, say, as a tool with which to zoom-in or -out with regard to multi

  9. Global P-Delta effects in seismic demand evaluation of vibration controlled steel frames

    E-Print Network [OSTI]

    Pendse, Jaydeep Dilip


    The goal of the research was to investigate the effect of global P-Delta on the seismic response of structures. A SAC II three story structure and a reduced order portal frame were the focus of study. The motivation to carry out the research...

  10. tance. The frame in the middle shows the structure outlined above, with both

    E-Print Network [OSTI]

    Comerón, Fernando

    and thermal conduc­ tion at work in the hot gas. The top frame shows the same results, but now assuming gas. The shape of the bow shock is in this case much more irregu­ lar; this is due to the chaotic and from the stellar wind, having very different velocities along the bow shock, get in contact. Finally

  11. Upstream open reading frames cause widespread reduction of protein expression and are polymorphic among humans

    E-Print Network [OSTI]

    Calvo, Sarah E.

    Upstream ORFs (uORFs) are mRNA elements defined by a start codon in the 5? UTR that is out-of-frame with the main coding sequence. Although uORFs are present in approximately half of human and mouse transcripts, no study ...

  12. Component/OEM XC-HR50 High Frame Rate Monochrome Camera

    E-Print Network [OSTI]

    Demoulin, Pascal

    Monochrome Camera B/W Progressive Scan Cameras #12;These new cameras expand the range of products in Sony's progressive scan and high-frame rate, compact camera line up! Introducing the newest additions to Sony's B/sec. for compatibility with slower vision systems using Sony XC-55 cameras. The XC-HR50 and XC-HR70 cameras incorporate

  13. Standard Operating Procedure (SOP) for MTS Single Acting Frame With UniTest

    E-Print Network [OSTI]

    Thompson, Michael


  14. Data-driven tight frame construction and image Jian-Feng Caia

    E-Print Network [OSTI]

    Shen, Zuowei

    approximation. However, the structure of images varies greatly in practice and a system working well for one for image restoration assume that the underlying image has a good sparse approximation under a certain system. Such a system can be a basis, a frame, or a general over-complete dictionary. One widely used

  15. Cost-effective Printing of 3D Objects with Skin-Frame Structures Weiming Wang,

    E-Print Network [OSTI]

    Deng, Jiansong

    ; Keywords: 3D printing, fabrication, frame structure, sparsity op- timization Corresponding author: (Zhouwang Yang) 1 Introduction Additive manufacturing (3D printing) enables fabrication of physi- cal techniques of 3D printing has received considerable attention for assisting users to generate desired

  16. Evaluation of the effect of contact between risers and guide frames on offshore spar platform motions

    E-Print Network [OSTI]

    Koo, Bon-Jun


    buoyancy-cans inside the spar moon-pool on the global spar motions. The gap between the buoyancy can and riser guide frames are modeled using three different types of nonlinear gap springs. The new riser model also considers the Coulomb damping between...

  17. A Reference-Frame for Installing the Student's Computer to Access a Virtual Medicine University

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the setup - system and the reference-frame. Services concerning the management of the student' computer management (especially confidential issues), its installation and its testing have been enlightened. Those. De plus, ce référentiel est très utile pour un administrateur de site universitaire ou hospitalier

  18. Inter-frame dependent rate and distortion models for statistical multiplexing of video programs

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Inter-frame dependent rate and distortion models for statistical multiplexing of video Abstract--Statistical multiplexing (SM) is a useful technique for transmitting multiple video streams over of efficient SM algorithms is based on Rate and Distortion (R-D) information extracted from successive encoded

  19. Term definable classes of Boolean functions and frame definability in modal logic

    E-Print Network [OSTI]

    Földes, Stephan

    is a set function P(W) P(W). The truth condition for the modal operator in a model M based on a Scott. Hella, J. Kivel¨a Abstract. We establish a connection between term definability of Boolean functions if the corresponding class of Scott-Montague frames is defined by the translations of these functional terms, and vice


    E-Print Network [OSTI]

    Behrstock, Jason

    ON THE FRAME-STEWART ALGORITHM FOR THE TOWER OF HANOI MICHAEL RAND 1. Introduction The Tower is to move the entire tower to another peg, while obeying the following restrictions: · Only one disk may have been: · What is the minimum number of moves required to transfer the entire tower from one peg