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Sample records for hydroprobe slim holes

  1. Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering...

    Open Energy Info (EERE)

    Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering Ltd, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Slim Holes At Blue...

  2. Coiled tubing used for slim hole re-entry

    SciTech Connect (OSTI)

    Traonmilin, E. ); Newman, K. )

    1992-02-17

    A coiled tubing unit with slim hole tools successfully re-entered and cored an existing Elf Aquitaine vertical well in the Paris basin in France. This experiment proved that coiled tubing could be used to drill, core, and test a slim hole well. Elf Aquitaine studied the use of coiled tubing for drilling inexpensive exploration wells in the Paris basin. As a result of this study, Elf believed that coiled tubing exploration drilling could significantly reduce exploration costs. This paper reports on a number of questions raised by this study: Can coiled tubing be used effectively to drill slim open hole How would the drilling rate compare with that of a conventional drilling rig If the rate were too slow, coiled tubing might not be economical. Can a straight vertical well be drilled Coiled tubing pipe has a residual curvature from bending over the reel and gooseneck. Will this curvature make it impossible to drill straight Can the coiled tubing also be used to take cores Once the hole is drilled, can it be tested with coiled tubing

  3. Geothermal reservoir assessment based on slim hole drilling. Volume 1, Analytical Method: Final report

    SciTech Connect (OSTI)

    Olson, H.J.

    1993-12-01

    The Hawaii Scientific Observation Hole (SOH) program was supplied by the State of Hawaii to drill six, 4,000 foot scientific observation holes on Maui and the Big Island of Hawaii to confirm and stimulate geothermal, resource development in Hawaii. After a lengthy permitting process, three SOHs, totaling 18,890 feet of mostly core drilling were finally drilled along the Kilauea East Rift Zone (KERZ) in the Puna district on the Big Island. The SOH program was highly successful in meeting the highly restrictive permitting conditions imposed on the program, and in developing slim hole drilling techniques, establishing subsurface geological conditions, and initiating an assessment and characterization of the geothermal resources potential of Hawaii - even though permitting specifically prohibited pumping or flowing the holes to obtain data of subsurface fluid conditions. The first hole, SOH-4, reached a depth of 2,000 meters, recorded a bottom hole temperature of 306.1 C, and established subsurface thermal continuity along the KERZ between the HGP-A and the True/Mid-Pacific Geothermal Venture wells. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole SOH-1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C, effectively doubled the size of the Hawaii Geothermal Project -- Abbott/Puna Geothermal Venture (HGP-A/PGV) proven/probable reservoir, and defined the northern limit of the HGP-A/PGV reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C, and has sufficient indicated permeability to be designated as a potential ''discovery.''

  4. Geothermal reservoir assessment based on slim hole drilling. Volume 2: Application in Hawaii: Final report

    SciTech Connect (OSTI)

    Olson, H.J.

    1993-12-01

    The Hawaii Scientific Observation Hole (SOH) program was planned, funded, and initiated in 1988 by the Hawaii Natural Energy Institute, an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa. Initial funding for the SOH program was $3.25 million supplied by the State of Hawaii to drill six, 4,000 foot scientific observation holes on Maui and the Big Island of Hawaii to confirm and stimulate geothermal resource development in Hawaii. After a lengthy permitting process, three SOHs, totaling 18,890 feet of mostly core drilling were finally drilled along the Kilauea East Rift Zone (KERZ) in the Puna district on the Big Island. The SOH program was highly successful in meeting the highly restrictive permitting conditions imposed on the program, and in developing slim hole drilling techniques, establishing subsurface geological conditions, and initiating an assessment and characterization of the geothermal resources potential of Hawaii - - even though permitting specifically prohibited pumping or flowing the holes to obtain data of subsurface fluid conditions. The first hole, SOH-4, reached a depth of 2,000 meters, recorded a/bottom hole temperature of 306.1 C, and established subsurface thermal continuity along the KERZ between the HGP-A and the True/Mid-Pacific Geothermal Venture wells. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole SOH-1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C, effectively doubled the size of the Hawaii Geothermal Project-Abbott/Puna Geothermal Venture (HGP-A/PGV) proven/probable reservoir, and defined the northern limit of the HGP-A/PGV reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C, and has sufficient indicated permeability to be designated as a potential discovery.

  5. A Study of Production/Injection Data from Slim Holes and Large-Diameter Wells at the Okuaizu Geothermal Field, Tohoku, Japan

    SciTech Connect (OSTI)

    Renner, Joel Lawrence; Garg, Sabodh K.; Combs, Jim

    2002-06-01

    Discharge from the Okuaizu boreholes is accompanied by in situ boiling. Analysis of cold-water injection and discharge data from the Okuaizu boreholes indicates that the two-phase productivity index is about an order of magnitude smaller than the injectivity index. The latter conclusion is in agreement with analyses of similar data from Oguni, Sumikawa, and Kirishima geothermal fields. A wellbore simulator was used to examine the effect of borehole diameter on the discharge capacity of geothermal boreholes with two-phase feedzones. Based on these analyses, it appears that it should be possible to deduce the discharge characteristics of largediameter wells using test data from slim holes with two-phase feeds.

  6. Slim Holes | Open Energy Information

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  7. Category:Slim Holes | Open Energy Information

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  8. Hydroprobe | Open Energy Information

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  9. Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering Ltd,

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  10. Slim Holes At Alum Area (DOE GTP) | Open Energy Information

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  11. Slim Holes At Maui Area (DOE GTP) | Open Energy Information

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  12. SLIM, Short-pulse Technology for High Gradient Induction Accelerators

    SciTech Connect (OSTI)

    Arntz, Floyd; Kardo-Sysoev, A.; Krasnykh, A.; /SLAC

    2008-12-16

    A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960's. Because this approach avoids use of magnetic materials there is the prospect of such an accelerator working efficiently with accelerating pulses in the nanosecond range and, potentially, at megahertz pulse rates. The principal accelerator section is envisioned as a stack of coreless induction cells, the only active element within each being a single, extremely fast (subnanosecond) solid state opening switch: a Drift Step Recovery Diode (DSRD). Each coreless induction cell incorporates an electromagnetic pulse compressor in which inductive energy developed within a transmission-line feed structure over a period of tens of nanoseconds is diverted to the acceleration of the passing charge packet for a few nanoseconds by the abrupt opening of the DSRD switch. The duration of this accelerating output pulse--typically two-to-four nanoseconds--is precisely determined by a microfabricated pulse forming line connected to the cell. Because the accelerating pulse is only nanoseconds in duration, longitudinal accelerating gradients approaching 100 MeV per meter are believed to be achievable without inciting breakdown. Further benefits of this approach are that, (1) only a low voltage power supply is required to produce the high accelerating gradient, and, (2) since the DSRD switch is normally closed, voltage stress is limited to a few nanoseconds per period, hence the susceptibility to hostile environment conditions such as ionizing radiation, mismatch (e.g. in medical applications the peak beam current may be low), strong electromagnetic noise levels, etc is expected to be minimal. Finally, we observe the SLIM concept is not limited to linac applications; for instance, it could be employed to both accelerate the beam and to stabilize the superbunch mode of operation in circular track machines.

  13. SLIM first user of the day Turn the key on the laser

    E-Print Network [OSTI]

    Yavuz, Deniz

    1 SLIM first user of the day Turn the key on the laser controller from "STANDBY" to "ON". The laser controller, shown in the image below reads "Status: OK." Open the new laser control program on the computer

  14. Topography and refractometry of nanostructures using spatial light interference microscopy (SLIM)

    E-Print Network [OSTI]

    Gillette, Martha U.

    Topography and refractometry of nanostructures using spatial light interference microscopy (SLIM topography at a single atomic layer in graphene. Further, using a decoupling procedure that we developed high- throughput topography and refractometry of man-made and biological nanostructures. Quantitative

  15. Phase 2 Reese River Geothermal Project Slim Well 56-4 Drilling and Testing

    SciTech Connect (OSTI)

    Henkle, William R.; Ronne, Joel

    2008-06-15

    This report covers the drilling and testing of the slim well 56-4 at the Reese River Geothermal Project in Lander County, Nevada. This well was partially funded through a GRED III Cooperative Funding Agreement # DE-FC36-04GO14344, from USDOE.

  16. Horizontal slim-hole drilling with coiled tubing; An operator's experience

    SciTech Connect (OSTI)

    Ramos, A.B. Jr.; Faahel, R.A.; Chaffin, M.G.; Pulis, K.H. )

    1992-10-01

    What is believed to be the first horizontal well drilled with directionally controlled coiled tubing recently was completed in the Austin Chalk formation. an existing well was sidetracked out of 4 1/2-in. casing with a conventional whipstock. an average build rate of 15[degrees]/100 ft was achieved in the curve, and a 1,458-ft vertical section was drilled with 2-in. coiled tubing, downhole mud motors, wireline steering tools, a mechanical downhole orienting tool, and 3 7/8-in. bits. This paper discusses the orienting and directional tools and techniques developed during this operation. It also describes improvements made for the second well.

  17. Slim Holes At Alvord Hot Springs Area (Combs, Et Al., 1999) | Open Energy

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  18. Slim Holes At Hawthorne Area (Sabin, Et Al., 2010) | Open Energy

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  19. Slim Holes At Salt Wells Area (Combs, Et Al., 1999) | Open Energy

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  20. Slim Holes At Salton Sea Area (Sabin, Et Al., 2010) | Open Energy

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  1. Slim Holes At Vale Hot Springs Area (Combs, Et Al., 1999) | Open Energy

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  2. Slim Holes At Black Warrior Area (DOE GTP) | Open Energy Information

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  3. Slim Holes At Blue Mountain Area (Warpinski, Et Al., 2002) | Open Energy

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  4. Slim Holes At Crump's Hot Springs Area (DOE GTP) | Open Energy Information

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  5. Slim Holes At Fish Lake Valley Area (Deymonaz, Et Al., 2008) | Open Energy

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  6. Slim Holes At Flint Geothermal Area (DOE GTP) | Open Energy Information

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  7. Slim Holes At Fort Bliss Area (Combs, Et Al., 1999) | Open Energy

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  8. Slim Holes At Fort Bliss Area (DOE GTP) | Open Energy Information

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  9. Slim Holes At Gabbs Valley Area (DOE GTP) | Open Energy Information

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  10. Slim Holes At Glass Buttes Area (DOE GTP) | Open Energy Information

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  11. Slim Holes At Hot Pot Area (DOE GTP) | Open Energy Information

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  12. Slim Holes At International Geothermal Area, Japan (Combs, Et Al., 1999) |

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  13. Slim Holes At Jemez Pueblo Area (DOE GTP) | Open Energy Information

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  14. Slim Holes At New River Area (DOE GTP) | Open Energy Information

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  15. Slim Holes At Newberry Caldera Area (Combs, Et Al., 1999) | Open Energy

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  16. Slim Holes At Newberry Caldera Area (DOE GTP) | Open Energy Information

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  17. Slim Holes At Reese River Area (Henkle & Ronne, 2008) | Open Energy

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  18. Slim Holes At Silver Peak Area (DOE GTP) | Open Energy Information

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  19. Slim Holes At Snake River Plain Region (DOE GTP) | Open Energy Information

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  20. Slim Holes At Steamboat Springs Area (Combs, Et Al., 1999) | Open Energy

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  1. Slim Holes At Steamboat Springs Area (Warpinski, Et Al., 2002) | Open

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  2. Slim Holes At Steamboat Springs Area (Warpinski, Et Al., 2004) | Open

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  3. Role of Disk models in Indentifying Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    We discuss how disk models may limit the scope of identifying astrophysical black holes. We show that the standard Keplerian thin disk model, the thick disk model, slim disks, ADAFs etc. are fundamentally limited. We present the most complete solution to date called the advective accretion disk and discuss how it has the scope to address every observational aspects of a black hole. Though the magnetic field is not fully self-consistently taken care of yet, the details with which the present model can handle various issues successfully are astounding. We present some of the examples.

  4. Grand Unified Model of Accretion Disks Around Black Holes: the Sub-Keplerian Paradigm

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1995-02-06

    We show that viscous, transonic accretion disks which start with sub-Keplerian angular momentum at the outer boundary reproduce the features of the so-called thick, thin, slim and other accretion disk models depending upon the accretion rates and viscosity parameters. These disks are advection dominated in the pre-shock region and rotation dominated in the post-shock region when viscosity is less than a critical value. For a higher viscosity the shock disappears, and the flow has significant radial velocity only close to the black hole.

  5. Flexible Proportional-Rate Scheduling for OFDMA Alex Leith, Mohamed-Slim Alouini, Fellow, IEEE, Dong In Kim, Senior Member, IEEE, Xuemin (Sherman)

    E-Print Network [OSTI]

    Shen, Xuemin "Sherman"

    Flexible Proportional-Rate Scheduling for OFDMA System Alex Leith, Mohamed-Slim Alouini, Fellow orthogonal frequency divi- sion multiple access (OFDMA) systems under proportional-rate constraint (PRC with either short-term or long-term fairness. Index Terms--OFDMA, proportional rate constraint (PRC

  6. Preliminary results and status report of the Hawaiian Scientific Observation Hole program

    SciTech Connect (OSTI)

    Olson, Harry J.; Deymonaz, John E.

    1992-01-01

    The Hawaii Natural Energy Institute (HNEI), an institute within the School of Ocean and Earth Science and Technology, at the University of Hawaii at Manoa has drilled three Scientific Observation Holes (SOH) in the Kilauea East Rift Zone to assess the geothermal potential of the Big Island of Hawaii, and to stimulate private development of the resource. The first hole drilled, SOH-4, reached a depth of 2,000 meters and recorded a bottom hole temperature of 306 C. Although evidence of fossil reservoir conditions were encountered, no zones with obvious reservoir potential were found. The second hole, SOH- 1, was drilled to a depth of 1,684 meters, recorded a bottom hole temperature of 206.1 C and effectively defined the northern limit of the Hawaii Geothermal Project-Abbott--Puna Geothermal Venture (HGP-A/PGV) reservoir. The final hole, SOH-2, was drilled to a depth of 2,073 meters, recorded a bottom hole temperature of 350.5 C and has sufficient indicated permeability to be designated as a potential ''discovery''. The SOH program was also highly successful in developing slim hole drilling techniques and establishing subsurface geological conditions.

  7. Hydroprobe At Gabbs Valley Area (DOE GTP) | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: Energy Resources JumpNewTexas: EnergyHunterdonHutto,FuelEnergyGabbs Valley Area (DOE

  8. Hydroprobe At Mcgee Mountain Area (DOE GTP) | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam: Energyarea,MagazineTechnologiesInformationOpen

  9. Black Warrior: Sub-soil gas and fluid inclusion exploration and slim well drilling

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. Project Objectives: Discover a blind, low-moderate temperature resource: Apply a combination of detailed sub-soil gas, hydrocarbon, and isotope data to define possible upflow areas; Calibrate the sub-soil chemistry with down-hole fluid inclusion stratigraphy and fluid analyses to define a follow-up exploration drilling target; Create short term jobs and long term employment through resource exploration, development and power plant operation; Extend and adapt the DOE sub-soil 2 meter probe technology to gas sampling.

  10. Coronal Holes

    E-Print Network [OSTI]

    Cranmer, Steven R

    2009-01-01

    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...

  11. Supermassive Black Holes

    E-Print Network [OSTI]

    Laura Ferrarese; David Merritt

    2002-06-13

    After a brief historical introduction, we summarize current efforts and accomplishments in the study of supermassive black holes.

  12. Accreting Black Holes

    E-Print Network [OSTI]

    Begelman, Mitchell C

    2014-01-01

    I outline the theory of accretion onto black holes, and its application to observed phenomena such as X-ray binaries, active galactic nuclei, tidal disruption events, and gamma-ray bursts. The dynamics as well as radiative signatures of black hole accretion depend on interactions between the relatively simple black-hole spacetime and complex radiation, plasma and magnetohydrodynamical processes in the surrounding gas. I will show how transient accretion processes could provide clues to these interactions. Larger global magnetohydrodynamic simulations as well as simulations incorporating plasma microphysics and full radiation hydrodynamics will be needed to unravel some of the current mysteries of black hole accretion.

  13. Rotating Hairy Black Holes

    E-Print Network [OSTI]

    B. Kleihaus; J. Kunz

    2000-12-20

    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.

  14. "Hybrid" Black Holes

    E-Print Network [OSTI]

    Valeri P. Frolov; Andrei V. Frolov

    2014-12-30

    We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

  15. Black Holes and Galaxy Evolution

    E-Print Network [OSTI]

    David Merritt

    1999-10-29

    Supermassive binary black holes and their influence on the structure and evolution of galaxies is reviewed.

  16. Calibration of a Neutron Hydroprobe for Moisture Measurements in Small-Diameter Steel-Cased Boreholes

    SciTech Connect (OSTI)

    Ward, Anderson L.; Wittman, Richard S.

    2009-08-01

    Computation of soil moisture content from thermalized neutron counts for the T-Farm Interim cover requires a calibration relationship but none exists for 2-in tubes. A number of calibration options are available for the neutron probe, including vendor calibration, field calibration, but none of these methods were deemed appropriate for the configuration of interest. The objective of this work was to develop a calibration relation for converting neutron counts measured in 2-in access tubes to soil water content. The calibration method chosen for this study was a computational approach using the Monte Carlo N-Particle Transport Code (MCNP). Model calibration was performed using field measurements in the Hanford calibration models with 6-in access tubes, in air and in the probe shield. The bet-fit model relating known water content to measured neutron counts was an exponential model that was essentially equivalent to that currently being used for 6-in steel cased wells. The MCNP simulations successfully predicted the neutron count rate for the neutron shield and the three calibration models for which data were collected in the field. However, predictions for air were about 65% lower than the measured counts . This discrepancy can be attributed to uncertainties in the configuration used for the air measurements. MCNP-simulated counts for the physical models were essentially equal to the measured counts with values. Accurate prediction of the response in 6-in casings in the three calibration models was motivation to predict the response in 2-in access tubes. Simulations were performed for six of the seven calibration models as well as 4 virtual models with the entire set covering a moisture range of 0 to 40%. Predicted counts for the calibration models with 2-in access tubes were 40 to 50% higher than in the 6-inch tubes. Predicted counts for water were about 60% higher in the 2-in tube than in the 6-in tube. The discrepancy between the 2-in and 6-in tube can be attributed to the smaller air gap between the probe and the 2-in access tube. The best-fit model relating volumetric water content to count ratio (CR) is of the form e^A x CR^B with A=0.3596 ± 0.0216 and B=0.4629 ± 0.0629 and r^2= 0.9998. It is recommended that the calibration function based on the count ratio, rather than raw counts, be used to avoid the effects of electronic noise in the probe that may arise due to the conditions at the time of measurement. These results suggest that the MCNP code can be used to extend calibrations for the neutron probe to different conditions including access tube size as well as composition without the need to construct additional physical models.

  17. Black Holes In Astronomy Black Holes In Astronomy

    E-Print Network [OSTI]

    Wagner, Stephan

    Black Hole horizon static limit ergosphere radiation magnetic fields jet jet #12;Black-hole accretion with a central bulge. #12;Click to edit Master text styles Second level Third level Fourth level Fifth level Jets and lobes of Cygnus A Carilli et al. Supermassive black holes are the most powerful engines in the Universe

  18. Holes in Spectral Lines

    E-Print Network [OSTI]

    Fontana, Peter R.; Srivastava, Rajendra P.

    1973-06-01

    at E = 0 is 2le I' Ib/(t)I = @~ R~R~~»nh'(IRlyt)e"'" (13)a ylal 0 5 '7 FIG. 3. Probabilities of photon emission as a function of time. The frequency corresponds to the energy differ- ence between the unperturbed degenerate excited states and the ground... states 6 is 0. 5 ey. For V= 0 the emission line is Lorentzian, but for V0 a "hole" appears at the frequency equal to the frequency difference between the excited nondecay- ing state and the ground state. The position of the "hole" is independent...

  19. Black Holes And Their Entropy 

    E-Print Network [OSTI]

    Mei, Jianwei

    2010-10-12

    . . . . . . . . . 21 1. Solutions in Four Dimensions . . . . . . . . . . . . . . 22 2. Solutions in Higher Dimensions . . . . . . . . . . . . . 27 C. Black Hole Solutions in Supergravity Theories . . . . . . . 30 D. Plebanski-Demianski Type Solutions in d = 5... is to discuss the construction of new black hole solutions and the calculation of the black hole entropy. In Chapter II, we shall re- port some new black hole solutions that we have found during the past few years [21, 22, 23] and we will discuss some...

  20. Deep Blue No.1-A Slimhole Geothermal Discovery At Blue Mountain...

    Open Energy Info (EERE)

    Area (Fairbank & Niggemann, 2004) Slim Holes At Blue Mountain Geothermal Area (Fairbank Engineering Ltd, 2003) Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank &...

  1. Black Holes at Accelerators

    E-Print Network [OSTI]

    Bryan Webber

    2006-04-06

    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.

  2. Quantum black hole inflation

    E-Print Network [OSTI]

    M. B. Altaie

    2001-05-07

    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.

  3. 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

    2014-01-14

    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.

  4. Statistical Mechanics of Black Holes

    E-Print Network [OSTI]

    B. Harms; Y. Leblanc

    1992-05-11

    We analyze the statistical mechanics of a gas of neutral and charged black holes. The microcanonical ensemble is the only possible approach to this system, and the equilibrium configuration is the one for which most of the energy is carried by a single black hole. Schwarzschild black holes are found to obey the statistical bootstrap condition. In all cases, the microcanonical temperature is identical to the Hawking temperature of the most massive black hole in the gas. U(1) charges in general break the bootstrap property. The problems of black hole decay and of quantum coherence are also addressed.

  5. Black Hole Scan

    E-Print Network [OSTI]

    Juan Crisostomo; Ricardo Troncoso; Jorge Zanelli

    2000-09-22

    Gravitation theories selected by requiring that they have a unique anti-de Sitter vacuum with a fixed cosmological constant are studied. For a given dimension d, the Lagrangians under consideration are labeled by an integer k=1,2,...,[(d-1)/2]. Black holes for each d and k are found and are used to rank these theories. A minimum possible size for a localized electrically charged source is predicted in the whole set of theories, except General Relativity. It is found that the thermodynamic behavior falls into two classes: If d-2k=1, these solutions resemble the three dimensional black hole, otherwise, their behavior is similar to the Schwarzschild-AdS_4 geometry.

  6. Black holes at accelerators.

    E-Print Network [OSTI]

    Webber, Bryan R

    be presented and the effects of some of the uncertainties can be investigated. 3.1. Hawking Spectrum With the above assumptions, the spectrum of particles emitted during black hole decay takes the form dN dE ? ?E2 (eE/TH ? 1) T n+6H (8) where as usual... the trapped surface area [6, 7]. T030 02 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E rS ?ˆ (0 ) ab s/ pi r2 S Figure 4: Grey-body factors for scalar emission on the brane from a (4 + n)D black hole. 0 2 4 6 8 10 0 0.2 0.4 0.6 0.8 1 1.2 n=0 n=1 n=2 n=6 E...

  7. Black Hole Demographics

    E-Print Network [OSTI]

    Laura Ferrarese

    2002-03-04

    The purpose of this contribution is to review the current status of black hole demographics in light of recent advances in the study of high redshift QSOs (section 2), local AGNs (section 3) and local quiescent galaxies (section 4). I will then outline the prospects for future progress (section 5), and discuss what I believe will be the challenges for the years to come [ABRIDGED].

  8. Identification of Astrophysical Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-03-19

    Black holes are by definition black, and therefore cannot be directly observed by using electromagnetic radiations. Convincing identification of black holes must necessarily depend on the identification of a very specially behaving matter and radiation which surround them. A major problem in this subject of black hole astrophysics is to quantify the behaviour of matter and radiation close to the horizon. In this review, the subject of black hole accretion and outflow is systematically developed. It is shown that both the stationary as well as the non-stationary properties of the observed spectra could be generally understood by these solutions. It is suggested that the solutions of radiative hydrodynamic equations may produce clear spectral signatures of black holes. Other circumstantial evidences of black holes, both in the galactic centers as well as in binary systems, are also presented.

  9. Black holes in general relativity

    E-Print Network [OSTI]

    Visser, Matt

    2009-01-01

    What is going on (as of August 2008) at the interface between theoretical general relativity, string-inspired models, and observational astrophysics? Quite a lot. In this mini-survey I will make a personal choice and focus on four specific questions: Do black holes "exist"? (For selected values of the word "exist".) Is black hole formation and evaporation unitary? Can one mimic a black hole to arbitrary accuracy? Can one detect the presence of a horizon using local physics?

  10. Quantum Mechanics and Black Holes

    E-Print Network [OSTI]

    Jose N. Pecina-Cruz

    2005-11-27

    This paper discusses the existence of black holes from the foundations of quantum mechanics. It is found that quantum mechanics rule out a possible gravitational collapse.

  11. Thermal BEC black holes

    E-Print Network [OSTI]

    Roberto Casadio; Andrea Giugno; Octavian Micu; Alessio Orlandi

    2015-11-04

    We review some features of BEC models of black holes obtained by means of the HWF formalism. We consider the KG equation for a toy graviton field coupled to a static matter current in spherical symmetry. The classical field reproduces the Newtonian potential generated by the matter source, while the corresponding quantum state is given by a coherent superposition of scalar modes with continuous occupation number. An attractive self-interaction is needed for bound states to form, so that (approximately) one mode is allowed, and the system of N bosons can be self-confined in a volume of the size of the Schwarzschild radius. The HWF is then used to show that the radius of such a system corresponds to a proper horizon. The uncertainty in the size of the horizon is related to the typical energy of Hawking modes: it decreases with the increasing of the black hole mass (larger number of gravitons), in agreement with semiclassical calculations and different from a single very massive particle. The spectrum contains a discrete ground state of energy $m$ (the bosons forming the black hole), and a continuous spectrum with energy $\\omega > m$ (representing the Hawking radiation and modelled with a Planckian distribution at the expected Hawking temperature). The $N$-particle state can be collectively described by a single-particle wave-function given by a superposition of a total ground state with energy $M = N m$ and a Planckian distribution for $E > M$ at the same Hawking temperature. The partition function is then found to yield the usual area law for the entropy, with a logarithmic correction related with the Hawking component. The backreaction of modes with $\\omega > m$ is also shown to reduce the Hawking flux and the evaporation properly stops for vanishing mass.

  12. Artificial ozone holes

    E-Print Network [OSTI]

    S. N. Dolya

    2014-10-18

    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.

  13. Holographic Black Hole Chemistry

    E-Print Network [OSTI]

    Andreas Karch; Brandon Robinson

    2015-11-02

    Thermodynamic quantities associated with black holes in Anti-de Sitter space obey an interesting identity when the cosmological constant is included as one of the dynamical variables, the generalized Smarr relation. We show that this relation can easily be understood from the point of view of the dual holographic field theory. It amounts to the simple statement that the extensive thermodynamic quantities of a large $N$ gauge theory only depend on the number of colors, $N$, via an overall factor of $N^2$.

  14. Black Holes of Negative Mass

    E-Print Network [OSTI]

    R. B. Mann

    1997-05-06

    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.

  15. 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

  16. Strings, higher curvature corrections, and black holes

    E-Print Network [OSTI]

    Thomas Mohaupt

    2005-12-05

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

  17. The Woods Hole Laboratory, 1885-1985

    E-Print Network [OSTI]

    The Woods Hole Laboratory, 1885-1985: A Century of Service Woods Hole Laboratory Northeast, Lectures, and Rededication of the Woods Hole Laboratory Contents Foreword and Acknowledgments Committees and Contributions of the Woods Hole Fisheries Laboratory Centennial Lecture II: The MBL and the Fisheries-A Century

  18. Black hole horizons Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  19. Thermodynamics of regular black hole

    E-Print Network [OSTI]

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

    2008-09-21

    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.

  20. Black Holes and Nuclear Dynamics

    E-Print Network [OSTI]

    David Merritt

    2006-02-17

    Supermassive black holes inhabit galactic nuclei, and their presence influences in crucial ways the evolution of the stellar distribution. The low-density cores observed in bright galaxies are probably a result of black hole infall, while steep density cusps like those at the Galactic center are a result of energy exchange between stars moving in the gravitational field of the single black hole. Loss-cone dynamics are substantially more complex in galactic nuclei than in collisionally-relaxed systems like globular clusters due to the wider variety of possible geometries and orbital populations. The rate of star-black hole interactions has begun to be constrained through observations of energetic events associated with stellar tidal disruptions.

  1. You Cannot Press Out the Black Hole

    E-Print Network [OSTI]

    Daisuke Ida; Takahiro Okamoto

    2012-01-03

    It is shown that a ball-shaped black hole region homeomorphic with D**n cannot be pressed out, along whichever axis penetrating the black hole region, into a black ring with a doughnut-shaped black hole region homeomorphic with S**1 x D**(n-1). A more general prohibition law for the change of the topology of black holes, including a version of no-bifurcation theorems for black holes, is given.

  2. Fishing in Black Holes

    E-Print Network [OSTI]

    A. Brotas

    2006-09-01

    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).

  3. Energy on black hole spacetimes

    E-Print Network [OSTI]

    Alejandro Corichi

    2012-07-18

    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.

  4. Heat Engine of black holes

    E-Print Network [OSTI]

    J. Sadeghi; Kh. Jafarzade

    2015-06-23

    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.

  5. Quantum Criticality and Black Holes

    ScienceCinema (OSTI)

    Sachdev, Subir [Harvard University, Cambridge, Massachusetts, United States

    2009-09-01

    I will describe the behavior of a variety of condensed matter systems in the vicinity of zero temperature quantum phase transitions. There is a remarkable analogy between the hydrodynamics of such systems and the quantum theory of black holes. I will show how insights from this analogy have shed light on recent experiments on the cuprate high temperature superconductors. Studies of new materials and trapped ultracold atoms are yielding new quantum phases, with novel forms of quantum entanglement. Some materials are of technological importance: e.g. high temperature superconductors. Exact solutions via black hole mapping have yielded first exact results for transport coefficients in interacting many-body systems, and were valuable in determining general structure of hydrodynamics. Theory of VBS order and Nernst effect in cuprates. Tabletop 'laboratories for the entire universe': quantum mechanics of black holes, quark-gluon plasma, neutrons stars, and big-bang physics.

  6. Black Holes and Galaxy Dynamics

    E-Print Network [OSTI]

    David Merritt

    1999-06-02

    The consequences of nuclear black holes for the structure and dynamics of stellar spheroids are reviewed. Slow growth of a black hole in a pre-existing core produces a steep power-law density profile similar to the cusps seen in faint elliptical galaxies. The weaker cusps in bright ellipticals may result from ejection of stars by a coalescing black-hole binary; there is marginal kinematical evidence for such a process having occurred in M87. Stellar orbits in a triaxial nucleus are mostly regular at radii where the gravitational force is dominated by the black hole; however the orbital shapes are not conducive to reinforcing the triaxial figure, hence nuclei are likely to be approximately axisymmetric. In triaxial potentials, a ``zone of chaos'' extends outward to a radius where the enclosed stellar mass is roughly 100 times the mass of the black hole; in this chaotic zone, no regular, box-like orbits exist. At larger radii, the phase space in triaxial potentials is complex, consisting of stochastic orbits as well as regular orbits associated with stable resonances. Figure rotation tends to increase the degree of stochasticity. Both test-particle integrations and N-body simulations suggest that a triaxial galaxy responds globally to the presence of a central mass concentration by evolving toward more axisymmetric shapes; the evolution occurs rapidly when the mass of the central object exceeds roughly 2% of the mass in stars. The lack of significant triaxiality in most early-type galaxies may be a consequence of orbital evolution induced by nuclear black holes.

  7. Introduction to Black Hole Evaporation

    E-Print Network [OSTI]

    Pierre-Henry Lambert

    2014-01-16

    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.

  8. Does phantom energy produce black hole?

    E-Print Network [OSTI]

    F. Rahaman; A. Ghosh; M. Kalam

    2006-12-23

    We have found an exact solution of spherically symmetrical Einstein equations describing a black hole with a special type phantom energy source. It is surprising to note that our solution is analogous to Reissner-Nordstr\\"{o}m black hole.

  9. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Ricardo Monteiro

    2010-06-28

    We consider the stability of black holes within both classical general relativity and the semiclassical thermodynamic description. In particular, we study linearised perturbations and their contribution to the gravitational partition function, addressing technical issues for charged (Reissner-Nordstrom) and rotating (Kerr-AdS) black holes. Exploring the connection between classical and thermodynamic stability, we find classical instabilities of Myers-Perry black holes and bifurcations to new black hole families.

  10. Will black holes eventually engulf the universe?

    E-Print Network [OSTI]

    Prado Martin-Moruno; Jose A. Jimenez Madrid; Pedro F. Gonzalez-Diaz

    2006-03-28

    The Babichev-Dokuchaev-Eroshenko model for the accretion of dark energy onto black holes has been extended to deal with black holes with non-static metrics. The possibility that for an asymptotic observer a black hole with large mass will rapidly increase and eventually engulf the Universe at a finite time in the future has been studied by using reasonable values for astronomical parameters. It is concluded that such a phenomenon is forbidden for all black holes in quintessential cosmological models.

  11. Hawking Emission and Black Hole Thermodynamics

    E-Print Network [OSTI]

    Don N. Page

    2006-12-18

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

  12. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Macedo, Caio F B; Crispino, Luís C B

    2015-01-01

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  13. Scattering by regular black holes: Planar massless scalar waves impinging upon a Bardeen black hole

    E-Print Network [OSTI]

    Caio F. B. Macedo; Ednilton S. de Oliveira; Luís C. B. Crispino

    2015-06-26

    Singularities are common features of general relativity black holes. However, within general relativity, one can construct black holes that present no singularities. These regular black hole solutions can be achieved by, for instance, relaxing one of the energy conditions on the stress energy tensor sourcing the black hole. Some regular black hole solutions were found in the context of non-linear electrodynamics, the Bardeen black hole being the first one proposed. In this paper, we consider a planar massless scalar wave scattered by a Bardeen black hole. We compare the scattering cross section computed using a partial-wave description with the classical geodesic scattering of a stream of null geodesics, as well as with the semi-classical glory approximation. We obtain that, for some values of the corresponding black hole charge, the scattering cross section of a Bardeen black hole has a similar interference pattern of a Reissner-Nordstr\\"om black hole.

  14. New approaches to black holes Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    References Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 2 / 36 Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 3 / 36 #12;Local (2006)] Eric Gourgoulhon (LUTH) New approaches to black holes Okinawa Nat. Col. Tech., 17 Aug 2008 4

  15. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

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

    2013-04-02

    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.

  16. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

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

    2005-03-08

    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.

  17. High precision, rapid laser hole drilling

    DOE Patents [OSTI]

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

    2007-03-20

    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.

  18. From Pinholes to Black Holes

    SciTech Connect (OSTI)

    Fenimore, Edward E.

    2014-10-06

    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.

  19. Extremal Higher Spin Black Holes

    E-Print Network [OSTI]

    Máximo Bañados; Alejandra Castro; Alberto Faraggi; Juan I. Jottar

    2015-11-30

    The gauge sector of three-dimensional higher spin gravities can be formulated as a Chern-Simons theory. In this context, a higher spin black hole corresponds to a flat connection with suitable holonomy (smoothness) conditions which are consistent with the properties of a generalized thermal ensemble. Building on these ideas, we discuss a definition of black hole extremality which is appropriate to the topological character of 3d higher spin theories. Our definition can be phrased in terms of the Jordan class of the holonomy around a non-contractible (angular) cycle, and we show that it is compatible with the zero-temperature limit of smooth black hole solutions. While this notion of extremality does not require nor implies the existence of supersymmetry, we exemplify its consequences in the context of sl(3|2) + sl(3|2) Chern-Simons theory. Remarkably, while as usual not all extremal solutions preserve supersymmetries, we find that the higher spin setup allows for non-extremal supersymmetric black hole solutions as well. Furthermore, we discuss our results from the perspective of the holographic duality between sl(3|2) + sl(3|2) Chern-Simons theory and two-dimensional CFTs with W_{(3|2)} symmetry, the simplest higher spin extension of the N=2 super-Virasoro algebra. In particular, we compute W_{(3|2)} BPS bounds at the full quantum level, and relate their semiclassical limit to extremal black hole or conical defect solutions in the 3d bulk. Along the way, we discuss the role of the spectral flow automorphism and provide a conjecture for the form of the semiclassical BPS bounds in general N=2 two-dimensional CFTs with extended symmetry algebras.

  20. On coupling impedances of pumping holes

    SciTech Connect (OSTI)

    Kurennoy, S.

    1993-04-01

    Coupling impedances of a single small hole in vacuum-chamber walls have been calculated at low frequencies. To generalize these results for higher frequencies and/or larger holes one needs to solve coupled integral equations for the effective currents. These equations are solved for two specific hole shapes. The effects of many holes at high frequencies where the impedances are not additive are studied using a perturbation-theory method. The periodic versus random distributions of the pumping holes in the Superconducting Super Collider liner are compared.

  1. Black hole mimickers: Regular versus singular behavior

    SciTech Connect (OSTI)

    Lemos, Jose P. S.; Zaslavskii, Oleg B.

    2008-07-15

    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.

  2. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, James W. (Aiken, SC); Cadieux, James R. (Aiken, SC)

    1996-01-01

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package.

  3. Detecting small holes in packages

    DOE Patents [OSTI]

    Kronberg, J.W.; Cadieux, J.R.

    1996-03-19

    A package containing a tracer gas, and a method for determining the presence of a hole in the package by sensing the presence of the gas outside the package are disclosed. The preferred tracer gas, especially for food packaging, is sulfur hexafluoride. A quantity of the gas is added to the package and the package is closed. The concentration of the gas in the atmosphere outside the package is measured and compared to a predetermined value of the concentration of the gas in the absence of the package. A measured concentration greater than the predetermined value indicates the presence of a hole in the package. Measuring may be done in a chamber having a lower pressure than that in the package. 3 figs.

  4. Black Hole Thermodynamics and Electromagnetism

    E-Print Network [OSTI]

    Burra G. Sidharth

    2005-07-15

    We show a strong parallel between the Hawking, Beckenstein black hole Thermodynamics and electromagnetism: When the gravitational coupling constant transform into the electromagnetic coupling constant, the Schwarzchild radius, the Beckenstein temperature, the Beckenstein decay time and the Planck mass transform to respectively the Compton wavelength, the Hagedorn temperature, the Compton time and a typical elementary particle mass. The reasons underlying this parallalism are then discussed in detail.

  5. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Addazi, Andrea

    2015-01-01

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  6. Quantum chaos inside Black Holes

    E-Print Network [OSTI]

    Andrea Addazi

    2015-08-30

    We show how semiclassical black holes can be reinterpreted as an effective geometry, composed of a large ensamble of horizonless naked singularities (eventually smoothed at the Planck scale). We call this new items {\\it frizzyballs}, which can be rigorously defined by euclidean path integral approach. This has interesting implications regarding information paradoxes. We demonstrate that infalling information will chaotically propagate inside this system before going to the full quantum gravity regime (Planck scale).

  7. Classical Black Holes Are Hot

    E-Print Network [OSTI]

    Erik Curiel

    2014-11-09

    In the early 1970s it is was realized that there is a striking formal analogy between the Laws of black-hole mechanics and the Laws of classical thermodynamics. Before the discovery of Hawking radiation, however, it was generally thought that the analogy was only formal, and did not reflect a deep connection between gravitational and thermodynamical phenomena. It is still commonly held that the surface gravity of a stationary black hole can be construed as a true physical temperature and its area as a true entropy only when quantum effects are taken into account; in the context of classical general relativity alone, one cannot cogently construe them so. Does the use of quantum field theory in curved spacetime offer the only hope for taking the analogy seriously? I think the answer is `no'. To attempt to justify that answer, I shall begin by arguing that the standard argument to the contrary is not physically well founded, and in any event begs the question. Looking at the various ways that the ideas of "temperature" and "entropy" enter classical thermodynamics then will suggest arguments that, I claim, show the analogy between classical black-hole mechanics and classical thermodynamics should be taken more seriously, without the need to rely on or invoke quantum mechanics. In particular, I construct an analogue of a Carnot cycle in which a black hole "couples" with an ordinary thermodynamical system in such a way that its surface gravity plays the role of temperature and its area that of entropy. Thus, the connection between classical general relativity and classical thermodynamics on their own is already deep and physically significant, independent of quantum mechanics.

  8. Down hole periodic seismic generator

    DOE Patents [OSTI]

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

    1989-01-01

    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.

  9. 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)

    2000-01-01

    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.

  10. Relationship of Black Holes to Bulges

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-07-08

    Supermassive black holes appear to be uniquely associated with galactic bulges. The mean ratio of black hole mass to bulge mass was until recently very uncertain, with ground based, stellar kinematical data giving a value roughly an order of magnitude larger than other techniques. The discrepancy was resolved with the discovery of the M-sigma relation, which simultaneously established a tight corrrelation between black hole mass and bulge velocity dispersion, and confirmed that the stellar kinematical mass estimates were systematically too large due to failure to resolve the black hole's sphere of influence. There is now excellent agreement between the various techniques for estimating the mean black hole mass, including dynamical mass estimation in quiescent galaxies; reverberation mapping in active galaxies and quasars; and computation of the mean density of compact objects based on integrated quasar light. Implications of the M-sigma relation for the formation of black holes are discussed.

  11. Boson shells harboring charged black holes

    SciTech Connect (OSTI)

    Kleihaus, Burkhard; Kunz, Jutta; Laemmerzahl, Claus; List, Meike

    2010-11-15

    We consider boson shells in scalar electrodynamics coupled to Einstein gravity. The interior of the shells can be empty space, or harbor a black hole or a naked singularity. We analyze the properties of these types of solutions and determine their domains of existence. We investigate the energy conditions and present mass formulae for the composite black hole-boson shell systems. We demonstrate that these types of solutions violate black hole uniqueness.

  12. Lower Dimensional Black Holes: Inside and Out

    E-Print Network [OSTI]

    R. B. Mann

    1995-01-27

    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.

  13. Black Holes: from Speculations to Observations

    E-Print Network [OSTI]

    Thomas W. Baumgarte

    2006-04-13

    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.

  14. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Wu, Xiaoning; Yuan, Pei-Hung; Cho, Chia-Jui

    2015-01-01

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  15. Rotating Black Holes and Coriolis Effect

    E-Print Network [OSTI]

    Xiaoning Wu; Yi Yang; Pei-Hung Yuan; Chia-Jui Cho

    2015-11-27

    In this work, we consider the fluid/gravity correspondence for general rotating black holes. By using the Petrov-like boundary condition in near horizon limit, we study the correspondence between gravitational perturbation and fluid equation. We find that the dual fluid equation for rotating black holes contains a Coriolis force term, which is closely related to the angular velocity of the black hole horizon. This can be seen as a dual effect for the frame-dragging effect of rotating black hole under the holographic picture.

  16. Core Holes | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTIONRobertsdale, Alabama (Utility Company)| Open(Evans,Oregon: EnergyInformationOpen1988)|Holes Jump

  17. Class Transitions in Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    A black hole spectrum is known to change from the hard state to the soft state when the energy spectral index $\\alpha$ ($F_E \\propto E^{-\\alpha}$) in, say, 2-20 keV range changes from $\\alpha \\sim 0.5$ to $\\sim 1.5$. However, this `classical' definition which characterizes black holes like Cyg X-1, becomes less useful for many objects such as GRS 1915+105 in which the spectral slope is seen to vary from one to the other in a matter of seconds and depending on whether or not winds form, the spectral slope also changes. The light curves and the colour-colour diagrams may look completely different on different days depending on the frequency and mode of switching from one spectral state to the other. Though RXTE observations have yielded wealth of information on such `variability classes' in GRS 1915+105, very rarely one has been able to observe how the object goes from one class to the other. In the present review, we discuss possible origins of the class transition and present several examples of such transitions. In this context, we use mostly the results of the Indian X-ray Astronomy Experiment (IXAE) which observed GRS 1915+105 more regularly.

  18. An electromagnetic black hole made of metamaterials

    E-Print Network [OSTI]

    Qiang Cheng; Tie Jun Cui; Wei Xiang Jiang; Ben Geng Cai

    2010-04-30

    Traditionally, a black hole is a region of space with huge gravitational field, which absorbs everything hitting it. In history, the black hole was first discussed by Laplace under the Newton mechanics, whose event horizon radius is the same as the Schwarzschild's solution of the Einstein's vacuum field equations. If all those objects having such an event horizon radius but different gravitational fields are called as black holes, then one can simulate certain properties of the black holes using electromagnetic fields and metamaterials due to the similar propagation behaviours of electromagnetic waves in curved space and in inhomogeneous metamaterials. In a recent theoretical work by Narimanov and Kildishev, an optical black hole has been proposed based on metamaterials, in which the theoretical analysis and numerical simulations showed that all electromagnetic waves hitting it are trapped and absorbed. Here we report the first experimental demonstration of such an electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can trap and absorb electromagnetic waves coming from all directions spirally inwards without any reflections due to the local control of electromagnetic fields and the event horizon corresponding to the device boundary. It is shown that the absorption rate can reach 99% in the microwave frequencies. We expect that the electromagnetic black hole could be used as the thermal emitting source and to harvest the solar light.

  19. Black holes cannot support conformal scalar hair

    E-Print Network [OSTI]

    T. Zannias

    1994-09-14

    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.

  20. Quantum Entropy of Charged Rotating Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-10

    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.

  1. Topological Black Holes in Quantum Gravity

    E-Print Network [OSTI]

    J. Kowalski-Glikman; D. Nowak-Szczepaniak

    2000-07-31

    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.

  2. Primordial black holes and asteroid danger

    E-Print Network [OSTI]

    Alexander Shatskiy

    2008-02-21

    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.

  3. Canonical structure of 2D black holes

    E-Print Network [OSTI]

    Navarro-Salas, J; Talavera, C F

    1994-01-01

    We determine the canonical structure of two-dimensional black-hole solutions arising in $2D$ dilaton gravity. By choosing the Cauchy surface appropriately we find that the canonically conjugate variable to the black hole mass is given by the difference of local (Schwarzschild) time translations at right and left spatial infinities. This can be regarded as a generalization of Birkhoff's theorem.

  4. Fractal Statistics and Quantum Black Hole Entropy

    E-Print Network [OSTI]

    Wellington da Cruz

    2000-11-18

    Simple considerations about the fractal characteristic of the quantum-mechanical path give us the opportunity to derive the quantum black hole entropy in connection with the concept of fractal statistics. We show the geometrical origin of the numerical factor of four of the quantum black hole entropy expression and the statistics weight appears as a counting of the quanta of geometry.

  5. Thermal Gradient Holes At Northern Basin & Range Region (Pritchett...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient Holes...

  6. Effective theories and black hole production in warped compactificatio...

    Office of Scientific and Technical Information (OSTI)

    Effective theories and black hole production in warped compactifications Citation Details In-Document Search Title: Effective theories and black hole production in warped...

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

    Open Energy Info (EERE)

    gradient holes up to 500' deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five....

  8. Brookhaven National Laboratory - Sr90 - Chemical Holes | Department...

    Office of Environmental Management (EM)

    - Chemical Holes Brookhaven National Laboratory - Sr90 - Chemical Holes January 1, 2014 - 12:00pm Addthis US Department of Energy Groundwater Database Groundwater Master Report...

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

    E-Print Network [OSTI]

    Lake, Matthew J

    2015-01-01

    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...

  10. Nonthermal correction to black hole spectroscopy

    E-Print Network [OSTI]

    Wen-Yu Wen

    2014-11-14

    Area spectrum of black holes have been obtained via various methods such as quasinormal modes, adiabatic invariance and angular momentum. Among those methods, calculations were done by assuming black holes in thermal equilibrium. Nevertheless, black holes in the asymptotically flat space usually have negative specific heat and therefore tend to stay away from thermal equilibrium. Even for those black holes with positive specific heat, temperature may still not be well defined in the process of radiation, due to the back reaction of decreasing mass. Respect to these facts, it is very likely that Hawking radiation is nonthermal and the area spectrum is no longer equidistant. In this note, we would like to illustrate how the area spectrum of black holes is corrected by this nonthermal effect.

  11. Fourier Analysis of the BTZ Black Hole

    E-Print Network [OSTI]

    Ian M. Tolfree

    2009-11-11

    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

  12. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan

    2003-10-23

    Astronomers have discovered many candidate black holes in X-ray binaries and in the nuclei of galaxies. The candidate objects are too massive to be neutron stars, and for this reason they are considered to be black holes. While the evidence based on mass is certainly strong, there is no proof yet that any of the objects possesses the defining characteristic of a black hole, namely an event horizon. Type I X-ray bursts, which are the result of thermonuclear explosions when gas accretes onto the surface of a compact star, may provide important evidence in this regard. Type I bursts are commonly observed in accreting neutron stars, which have surfaces, but have never been seen in accreting black hole candidates. It is argued that the lack of bursts in black hole candidates is compelling evidence that these objects do not have surfaces. The objects must therefore possess event horizons.

  13. How fast can a black hole rotate?

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    Kerr black holes have their angular momentum, $J$, bounded by their mass, $M$: $Jc\\leqslant GM^2$. There are, however, known black hole solutions violating this Kerr bound. We propose a very simple universal bound on the rotation, rather than on the angular momentum, of four-dimensional, stationary and axisymmetric, asymptotically flat black holes, given in terms of an appropriately defined horizon linear velocity, $v_H$. The $v_H$ bound is simply that $v_H$ cannot exceed the velocity of light. We verify the $v_H$ bound for known black hole solutions, including some that violate the Kerr bound, and conjecture that only extremal Kerr black holes saturate the $v_H$ bound.

  14. Radion clouds around evaporating black holes

    E-Print Network [OSTI]

    J. R. Morris

    2009-09-03

    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.

  15. Testing black hole candidates with electromagnetic radiation

    E-Print Network [OSTI]

    Bambi, Cosimo

    2015-01-01

    Astrophysical black hole candidates are thought to be the Kerr black holes of general relativity, but there is currently no direct observational evidence that the spacetime geometry around these objects is described by the Kerr solution. The study of the properties of the electromagnetic radiation emitted by gas or stars orbiting these objects can potentially test the Kerr black hole hypothesis. In this paper, I review the state of the art of this research field, describing the possible approaches to test the Kerr metric with current and future observational facilities and discussing current constraints.

  16. Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Quasinormal mode (QNM) gravitational radiation from black holes is expected to be observed in a few years. A perturbative formula is derived for the shifts in both the real and the imaginary part of the QNM frequencies away from those of an idealized isolated black hole. The formulation provides a tool for understanding how the astrophysical environment surrounding a black hole, e.g., a massive accretion disk, affects the QNM spectrum of gravitational waves. We show, in a simple model, that the perturbed QNM spectrum can have interesting features.

  17. Black hole microstates in AdS

    E-Print Network [OSTI]

    Shaghoulian, Edgar

    2015-01-01

    We extend a recently derived higher-dimensional Cardy formula to include angular momenta, which we use to obtain the Bekensten-Hawking entropy of AdS black branes, compactified rotating branes, and large Schwarzschild/Kerr black holes. This is the natural generalization of Strominger's microscopic derivation of the BTZ black hole entropy to higher dimensions. We propose an extension to include $U(1)$ charge, which agrees with the Bekenstein-Hawking entropy of large Reissner-Nordstrom/Kerr-Newman black holes at high temperature. We extend the results to arbitrary hyperscaling violation exponent (this captures the case of black D$p$-branes as a subclass) and reproduce logarithmic corrections.

  18. Some remarks on black hole thermodynamics

    E-Print Network [OSTI]

    R. Y. Chiao

    2011-02-04

    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.

  19. Thermodynamics of Dyonic Lifshitz Black Holes

    E-Print Network [OSTI]

    Tobias Zingg

    2011-07-15

    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.

  20. Testing the Kerr black hole hypothesis

    E-Print Network [OSTI]

    Cosimo Bambi

    2011-10-13

    It is thought that the final product of the gravitational collapse is a Kerr black hole and astronomers have discovered several good astrophysical candidates. While there is some indirect evidence suggesting that the latter have an event horizon, and therefore that they are black holes, a proof that the space-time around these objects is described by the Kerr geometry is still lacking. Recently, there has been an increasing interest in the possibility of testing the Kerr black hole hypothesis with present and future experiments. In this paper, I briefly review the state of the art of the field, focussing on some recent results and work in progress.

  1. Scalar Perturbations of Charged Dilaton Black Holes

    E-Print Network [OSTI]

    Sharmanthie Fernando; Keith Arnold

    2015-08-01

    We have studied the scalar perturbation of static charged dilaton black holes in 3+1 dimensions. The black hole considered here is a solution to the low-energy string theory in 3+1 dimensions. The quasinormal modes for the scalar perturbations are calculated using the third order WKB method. The dilaton coupling constant has a considerable effect on the values of quasi normal modes. It is also observed that there is a linear relation between the quasi normal modes and the temperature for large black holes.

  2. Is the Universe a White-Hole?

    E-Print Network [OSTI]

    Marcelo Samuel Berman

    2008-08-06

    Pathria(1972) has shown, for a pressureless closed Universe, that it is inside a black (or white) hole. We show now, that the Universe with a cosmic pressure obeying Einstein's field equations, can be inside a white-hole. In the closed case, a positive cosmological constant does the job; for the flat and open cases, the condition we find is not verified for the very early Universe, but with the growth of the scale-factor, the condition will be certainly fulfilled for a positive cosmological constant, after some time. We associate the absolute temperature of the Universe, with the temperature of the corresponding white-hole.

  3. Energy of 4-Dimensional Black Hole, etc

    E-Print Network [OSTI]

    Dmitriy Palatnik

    2011-07-18

    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.

  4. Horizon Operator Approach to Black Hole Quantization

    E-Print Network [OSTI]

    G. 't Hooft

    1994-02-21

    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\

  5. Radiation transport around Kerr black holes

    E-Print Network [OSTI]

    Schnittman, Jeremy David

    2005-01-01

    This Thesis describes the basic framework of a relativistic ray-tracing code for analyzing accretion processes around Kerr black holes. We begin in Chapter 1 with a brief historical summary of the major advances in black ...

  6. Topological Black Holes -- Outside Looking In

    E-Print Network [OSTI]

    R. B. Mann

    1997-09-15

    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.

  7. Time-bin entangled photon holes

    E-Print Network [OSTI]

    J. Liang; J. D. Franson; T. B. Pittman

    2012-08-23

    The general concept of entangled photon holes is based on a correlated absence of photon pairs in an otherwise constant optical background. Here we consider the specialized case when this background is confined to two well-defined time bins, which allows the formation of time-bin entangled photon holes. We show that when the typical coherent state background is replaced by a true single-photon (Fock state) background, the basic time-bin entangled photon-hole state becomes equivalent to one of the time-bin entangled photon-pair states. We experimentally demonstrate these ideas using a parametric down-conversion photon-pair source, linear optics, and post-selection to violate a Bell inequality with time-bin entangled photon holes.

  8. Evidence for the Black Hole Event Horizon

    E-Print Network [OSTI]

    Ramesh Narayan; Jeremy S. Heyl

    2002-04-26

    Roughly a dozen X-ray binaries are presently known in which the compact accreting primary stars are too massive to be neutron stars. These primaries are identified as black holes, though there is as yet no definite proof that any of the candidate black holes actually possesses an event horizon. We discuss how Type I X-ray bursts may be used to verify the presence of the event horizon in these objects. Type I bursts are caused by thermonuclear explosions when gas accretes onto a compact star. The bursts are commonly seen in many neutron star X-ray binaries, but they have never been seen in any black hole X-ray binary. Our model calculations indicate that black hole candidates ought to burst frequently if they have surfaces. Based on this, we argue that the lack of bursts constitutes strong evidence for the presence of event horizons in these objects.

  9. Black Hole Thermodynamics in Modified Gravity

    E-Print Network [OSTI]

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

    2015-03-03

    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.

  10. CHARYBDIS: A Black hole event generator.

    E-Print Network [OSTI]

    Harris, Chris M.; Richardson, P.; Webber, Bryan R.

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte...

  11. Spacetime constraints on accreting black holes

    SciTech Connect (OSTI)

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

    2009-06-15

    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.

  12. Thermodynamics and evaporation of the noncommutative black hole

    E-Print Network [OSTI]

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

    2007-01-21

    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.

  13. Classical and thermodynamic stability of black holes

    E-Print Network [OSTI]

    Monteiro, Ricardo

    2010-07-06

    Perturbations of the asymptotic charges . . . . . . . . . . . . . . . . 169 IV Conclusion 171 9 Conclusion and outlook 173 A Spectral numerical method 177 2 CONTENTS Part I Introduction 3 Chapter 1 Black holes Black holes are arguably the most interesting... to Newto- nian dynamics in the Solar system, and the indirect detection of gravitational waves from binary pulsars [1]. A crucial distinction from Newtonian gravity is that the “action-at-a-distance” is substituted by a built-in causality structure...

  14. Fractionated Branes and Black Hole Interiors

    E-Print Network [OSTI]

    Emil J. Martinec

    2015-05-20

    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.

  15. Solar Wind Forecasting with Coronal Holes

    E-Print Network [OSTI]

    S. Robbins; C. J. Henney; J. W. Harvey

    2007-01-09

    An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric magnetograms (e.g., Wang-Sheeley model) to estimate the open field line configuration. Rather than requiring the use of a full magnetic synoptic map, the method presented here can be used to forecast solar wind velocities and magnetic polarity from a single coronal hole image, along with a single magnetic full-disk image. The coronal hole parameters used in this study are estimated with Kitt Peak Vacuum Telescope He I 1083 nm spectrograms and photospheric magnetograms. Solar wind and coronal hole data for the period between May 1992 and September 2003 are investigated. The new model is found to be accurate to within 10% of observed solar wind measurements for its best one-month periods, and it has a linear correlation coefficient of ~0.38 for the full 11 years studied. Using a single estimated coronal hole map, the model can forecast the Earth directed solar wind velocity up to 8.5 days in advance. In addition, this method can be used with any source of coronal hole area and location data.

  16. Improving hole injection efficiency by manipulating the hole transport mechanism through

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    -emitting diodes (LEDs) for elec- tron overflow suppression. However, a typical EBL also reduces the hole injection to be the key to enhancing the hole injection efficiency. InGaN/ GaN LEDs with the proposed p-type AlGaN/GaN/AlGaN EBL have demonstrated substantially higher optical output power and external quantum efficiency

  17. Rotating black hole thermodynamics with a particle probe

    SciTech Connect (OSTI)

    Gwak, Bogeun; Lee, Bum-Hoon

    2011-10-15

    The thermodynamics of Myers-Perry black holes in general dimensions are studied using a particle probe. When undergoing particle absorption, the changes of the entropy and irreducible mass are shown to be dependent on the particle radial momentum. The black hole thermodynamic behaviors are dependent on dimensionality for specific rotations. For a 4-dimensional Kerr black hole, its black hole properties are maintained for any particle absorption. 5-dimensional black holes can avoid a naked ring singularity by absorbing a particle in specific momenta ranges. Black holes over 6 dimensions become ultraspinning black holes through a specific form of particle absorption. The microscopical changes are interpreted in limited cases of Myers-Perry black holes using Kerr/CFT correspondence. We systematically describe the black hole properties changed by particle absorption in all dimensions.

  18. The Revival of White Holes as Small Bangs

    E-Print Network [OSTI]

    Alon Retter; Shlomo Heller

    2011-07-17

    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.

  19. Holographic superconductor in the exact hairy black hole

    E-Print Network [OSTI]

    Yun Soo Myung; Chanyong Park

    2011-09-13

    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. Electrically charged black hole with scalar hair

    E-Print Network [OSTI]

    Cristian Martinez; Ricardo Troncoso

    2006-06-16

    An electrically charged black hole solution with scalar hair in four dimensions is presented. The self-interacting scalar field is real and it is minimally coupled to gravity and electromagnetism. The event horizon is a surface of negative constant curvature and the asymptotic region is locally an AdS spacetime. The asymptotic fall-off of the fields is slower than the standard one. The scalar field is regular everywhere except at the origin, and is supported by the presence of electric charge which is bounded from above by the AdS radius. In turn, the presence of the real scalar field smooths the electromagnetic potential everywhere. Regardless the value of the electric charge, the black hole is massless and has a fixed temperature. The entropy follows the usual area law. It is shown that there is a nonvanishing probability for the decay of the hairy black hole into a charged black hole without scalar field. Furthermore, it is found that an extremal black hole without scalar field is likely to undergo a spontaneous dressing up with a nontrivial scalar field, provided the electric charge is below a critical value.

  1. The Environmental Impact of Supermassive Black Holes

    E-Print Network [OSTI]

    Abraham Loeb

    2004-08-10

    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.

  2. BLACK HOLE FORAGING: FEEDBACK DRIVES FEEDING

    SciTech Connect (OSTI)

    Dehnen, Walter; King, Andrew, E-mail: wd11@leicester.ac.uk, E-mail: ark@astro.le.ac.uk [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)] [Theoretical Astrophysics Group, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2013-11-10

    We suggest a new picture of supermassive black hole (SMBH) growth in galaxy centers. Momentum-driven feedback from an accreting hole gives significant orbital energy, but little angular momentum to the surrounding gas. Once central accretion drops, the feedback weakens and swept-up gas falls back toward the SMBH on near-parabolic orbits. These intersect near the black hole with partially opposed specific angular momenta, causing further infall and ultimately the formation of a small-scale accretion disk. The feeding rates into the disk typically exceed Eddington by factors of a few, growing the hole on the Salpeter timescale and stimulating further feedback. Natural consequences of this picture include (1) the formation and maintenance of a roughly toroidal distribution of obscuring matter near the hole; (2) random orientations of successive accretion disk episodes; (3) the possibility of rapid SMBH growth; (4) tidal disruption of stars and close binaries formed from infalling gas, resulting in visible flares and ejection of hypervelocity stars; (5) super-solar abundances of the matter accreting on to the SMBH; and (6) a lower central dark-matter density, and hence annihilation signal, than adiabatic SMBH growth implies. We also suggest a simple subgrid recipe for implementing this process in numerical simulations.

  3. Perturbative String Thermodynamics near Black Hole Horizons

    E-Print Network [OSTI]

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

    2015-07-01

    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.

  4. Black Hole Spin in AGN and GBHCs

    E-Print Network [OSTI]

    Christopher S. Reynolds; Laura W. Brenneman; David Garofalo

    2004-10-05

    We discuss constraints on black hole spin and spin-related astrophysics as derived from X-ray spectroscopy. After a brief discussion about the robustness with which X-ray spectroscopy can be used to probe strong gravity, we summarize how these techniques can constrain black hole spin. In particular, we highlight XMM-Newton studies of the Seyfert galaxy MCG-6-30-15 and the stellar-mass black hole GX339-4. The broad X-ray iron line profile, together with reasonable and general astrophysical assumptions, allow a non-rotating black hole to be rejected in both of these sources. If we make the stronger assertion of no emission from within the innermost stable circular orbit, the MCG-6-30-15 data constrain the dimensionless spin parameter to be a>0.93. Furthermore, these XMM-Newton data are already providing evidence for exotic spin-related astrophysics in the central regions of this object. We conclude with a discussion of the impact that Constellation-X will have on the study of strong gravity and black hole spin.

  5. Investigating Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2009-06-08

    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.

  6. Neutrino Majorana Mass from Black Hole

    E-Print Network [OSTI]

    Yosuke Uehara

    2002-05-25

    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.

  7. Numerical Analysis of Black Hole Evaporation

    E-Print Network [OSTI]

    Tsvi Piran; Andrew Strominger

    1993-04-28

    Black hole formation/evaporation in two-dimensional dilaton gravity can be described, in the limit where the number $N$ of matter fields becomes large, by a set of second-order partial differential equations. In this paper we solve these equations numerically. It is shown that, contrary to some previous suggestions, black holes evaporate completely a finite time after formation. A boundary condition is required to evolve the system beyond the naked singularity at the evaporation endpoint. It is argued that this may be naturally chosen so as to restore the system to the vacuum. The analysis also applies to the low-energy scattering of $S$-wave fermions by four-dimensional extremal, magnetic, dilatonic black holes.

  8. No Supermassive Black Hole in M33?

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese; Charles L. Joseph

    2001-07-20

    We analyze optical long-slit spectroscopy of the nucleus of M33 obtained from the Space Telescope Imaging Spectrograph aboard the Hubble Space Telescope. Rather than the steep rise expected within the radius of influence of a supermassive black hole, the velocity dispersion drops significantly within the inner parsec. Dynamical modelling yields an estimated upper limit of 3000 solar masses for the mass of a central compact object. This upper limit is however consistent within the uncertainties with the mass predicted by the M-sigma relation, which is between 2000 and 20,000 solar masses. We therefore can not conclude that the presence of a massive black hole in the nucleus of M33 would require a different formation mechanism from that of the black holes detected in galaxies with more luminous bulges.

  9. Interior of Black Holes and Information Recovery

    E-Print Network [OSTI]

    Hikaru Kawai; Yuki Yokokura

    2015-09-28

    We analyze time evolution of a collapsing matter from a point of view that black holes evaporate by nature. We first consider a spherical thin shell that falls in the metric of an evaporating Schwarzschild black hole whose radius $a(t)$ decreases as $\\frac{da(t)}{dt}=-\\frac{2\\sigma(a(t))}{a(t)^2}$. The shell can never reach $a(t)$, but it approaches $a(t)+\\frac{2\\sigma(a(t))}{a(t)}$ in the time scale $\\sim a(t)$. Then the radiation from the hole is extremely weakened because of the large redshift caused by the shell. This time, however, the shell itself starts to radiate and exhausts energy. After that, the hole starts to radiate again. We can repeat this argument recursively because the motion of a shell in a spherically symmetric system is independent of the outside. In this way we can analyze a spherically symmetric collapsing matter with a general continuous distribution, and find that it evaporates without forming a trapped region. If the theory has considerably more species of matter fields, the trans-Planckian problems are avoided. There is a clear boundary at $r=a+\\frac{2\\sigma}{a}$ as the surface of the object. Although the matter distribution inside the object depends on the initial data, from the outside it looks almost the same as a conventional black hole. A strong angular pressure is induced by the Hawking radiation, because of which the matter loses energy when it collapses. We then discuss how the information of the matter is recovered in this picture. Next we consider a black hole that is adiabatically grown from a small one in the heat bath, and obtain the interior metric. We show that it is the self-consistent solution of $G_{\\mu\

  10. CHARYBDIS: A Black Hole Event Generator

    E-Print Network [OSTI]

    C. M. Harris; P. Richardson; B. R. Webber

    2003-07-29

    CHARYBDIS is an event generator which simulates the production and decay of miniature black holes at hadronic colliders as might be possible in certain extra dimension models. It interfaces via the Les Houches accord to general purpose Monte Carlo programs like HERWIG and PYTHIA which then perform the parton evolution and hadronization. The event generator includes the extra-dimensional `grey-body' effects as well as the change in the temperature of the black hole as the decay progresses. Various options for modelling the Planck-scale terminal decay are provided.

  11. Virtual Black Holes in Hyperbolic Metamaterials

    E-Print Network [OSTI]

    Igor I. Smolyaninov

    2011-01-24

    Optical space in electromagnetic metamaterials may be engineered to emulate various exotic space-time geometries. However, these metamaterial models are limited in many respects. It is believed that real physical space-time strongly fluctuates on the Planck scale. These fluctuations are usually described as virtual black holes. Static metamaterial models introduced so far do not exhibit similar behavior. Here we demonstrate that thermal fluctuations of optical space in hyperbolic metamaterials lead to creation of virtual electromagnetic black holes. This effect is very large if the dielectric component of the metamaterial exhibits critical opalescence.

  12. Vacuum polarization for lukewarm black holes

    E-Print Network [OSTI]

    Elizabeth Winstanley; Phil M. Young

    2007-12-20

    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.

  13. Thermal Gravitational Waves from Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun

    2010-05-19

    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.

  14. Thermal stability of radiant black holes

    E-Print Network [OSTI]

    Parthasarathi Majumdar

    2006-04-06

    Beginning with a brief sketch of the derivation of Hawking's theorem of horizon area increase, based on the Raychaudhuri equation, we go on to discuss the issue as to whether generic black holes, undergoing Hawking radiation, can ever remain in stable thermal equilibrium with that radiation. We derive a universal criterion for such a stability, which relates the black hole mass and microcanonical entropy, both of which are well-defined within the context of the Isolated Horizon, and in principle calculable within Loop Quantum Gravity. The criterion is argued to hold even when thermal fluctuations of electric charge are considered, within a {\\it grand} canonical ensemble.

  15. Black Hole Thermodynamics and Statistical Mechanics

    E-Print Network [OSTI]

    Steven Carlip

    2008-07-28

    We have known for more than thirty years that black holes behave as thermodynamic systems, radiating as black bodies with characteristic temperatures and entropies. This behavior is not only interesting in its own right; it could also, through a statistical mechanical description, cast light on some of the deep problems of quantizing gravity. In these lectures, I review what we currently know about black hole thermodynamics and statistical mechanics, suggest a rather speculative "universal" characterization of the underlying states, and describe some key open questions.

  16. Magnetized black hole as a gravitational lens

    E-Print Network [OSTI]

    R. A. Konoplya

    2006-11-19

    We use the Ernst-Schwarzschild solution for a black hole immersed in a uniform magnetic field to estimate corrections to the bending angle and time delay due-to presence of weak magnetic fields in galaxies and between galaxies, and also due-to influence of strong magnetic field near supermassive black holes. The magnetic field creates a kind of confinement in space, that leads to increasing of the bending angle and time delay for a ray of light propagating in the equatorial plane.

  17. Dynamics of galaxy cores and supermassive black holes

    E-Print Network [OSTI]

    David Merritt

    2006-05-02

    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. Black hole Meissner effect and Blandford-Znajek jets

    E-Print Network [OSTI]

    Penna, Robert

    Spinning black holes tend to expel magnetic fields. In this way they are similar to superconductors. It has been a persistent concern that this black hole “Meissner effect” could quench jet power at high spins. This would ...

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

    E-Print Network [OSTI]

    I. B. Khriplovich

    2002-03-31

    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.

  20. SEARCH FOR SUPERMASSIVE BLACK HOLE BINARIES IN THE SLOAN DIGITAL...

    Office of Scientific and Technical Information (OSTI)

    ASTROPHYSICS; BLACK HOLES; COMPARATIVE EVALUATIONS; CORRELATIONS; COSMOLOGY; GALAXIES; GALAXY NUCLEI; NONLUMINOUS MATTER; OSCILLATIONS; QUASARS; VELOCITY Word Cloud More Like This...

  1. MOTION OF ELECTRON-HOLE DROPS IN Ge

    E-Print Network [OSTI]

    Westervelt, R.M.

    2011-01-01

    MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.MOTION OF ELECTRON-HOLE DROPS IN Ge R. M. Westervelt, J. C.OF ELECTRON-HOLE DROPS IN Ge R M Westervelt, J C Culbertson

  2. ANCHIALINE ECOSYSTEMS Microbial hotspots in anchialine blue holes

    E-Print Network [OSTI]

    Macalady, Jenn

    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

  3. Light in tiny holes & T. W. Ebbesen1

    E-Print Network [OSTI]

    Turro, Nicholas J.

    REVIEWS Light in tiny holes C. Genet1 & T. W. Ebbesen1 The presence of tiny holes in an opaque metal film, with sizes smaller than the wavelength of incident light, leads to a wide variety of unexpected optical properties such as strongly enhanced transmission of light through the holes

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

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-06

    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.

  5. Charged fermions tunneling from accelerating and rotating black holes

    SciTech Connect (OSTI)

    Rehman, Mudassar; Saifullah, K., E-mail: mudassir051@yahoo.com, E-mail: saifullah@qau.edu.pk [Department of Mathematics, Quaid-i-Azam University, Islamabad (Pakistan)

    2011-03-01

    We study Hawking radiation of charged fermions from accelerating and rotating black holes with electric and magnetic charges. We calculate the tunneling probabilities of incoming and outgoing fermionic particles and find the Hawking temperature of these black holes. We also provide an explicit expression of the classical action for the massive and massless particles in the background of these black holes.

  6. Global Warming Hole 31 March 2015

    E-Print Network [OSTI]

    Hansen, James E.

    Global Warming Hole 31 March 2015 James Hansen Sorry to have disappeared for two months. I-thirds of North America know that global warming is really happening. In fact, 2015 should be the year that stifles discussion of a warming hiatus. A substantial developing El Nino will add to the global warming

  7. Brief review on higher spin black holes

    E-Print Network [OSTI]

    Alfredo Perez; David Tempo; Ricardo Troncoso

    2014-05-12

    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.

  8. Flip-flopping binary black holes

    E-Print Network [OSTI]

    Carlos O. Lousto; James Healy

    2015-03-14

    We study binary spinning black holes to display the long term individual spin dynamics. We perform a full numerical simulation starting at an initial proper separation of $d\\approx25M$ between equal mass holes and evolve them down to merger for nearly 48 orbits, 3 precession cycles, and half of a flip-flop cycle. The simulation lasts for $t=20000M$ and displays a total change in the orientation of the spin of one of the black holes from initially aligned with the orbital angular momentum to a complete anti-alignment after half of a flip-flop cycle. We compare this evolution with an integration of the 3.5 Post-Newtonian equations of motion and spin evolution to show that this process continuously flip-flops the spin during the lifetime of the binary until merger. We also provide lower order analytic expressions for the maximum flip-flop angle and frequency. We discuss the effects this dynamics may have on spin growth in accreting binaries and on the observational consequences for galactic and supermassive binary black holes.

  9. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Xing-Hui Feng; H. Lu; Qiang Wen

    2014-01-13

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead of being some continuous integration constants.

  10. Scalar Hairy Black Holes in General Dimensions

    E-Print Network [OSTI]

    Feng, Xing-Hui; Wen, Qiang

    2013-01-01

    We obtain a class of asymptotic flat or (A)dS hairy black holes in D-dimensional Einstein gravity coupled to a scalar with certain scalar potential. For a given mass, the theory admits both the Schwarzschild-Tangherlini and the hairy black holes with different temperature and entropy, but satisfying the same first law of thermodynamics. For some appropriate choice of parameters, the scalar potential can be expressed in terms of a super-potential and it can arise in gauged supergravities. In this case, the solutions develop a naked curvature singularity and become the spherical domain walls. Uplifting the solutions to D=11 or 10, we obtain solutions that can be viewed as spherical M-branes or D3-branes. We also add electric charges to these hairy black holes. All these solutions contain no scalar charges in that the first law of thermodynamics are unmodified. We also try to construct new AdS black holes carrying scalar charges, with some moderate success in that the charges are pre-fixed in the theory instead ...

  11. 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)

    2004-07-20

    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.

  12. Schwarzschild black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-09-27

    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.

  13. Lower-Dimensional Black Hole Chemistry

    E-Print Network [OSTI]

    Antonia M. Frassino; Robert B. Mann; Jonas R. Mureika

    2015-09-18

    The connection between black hole thermodynamics and chemistry is extended to the lower-dimensional regime by considering the rotating and charged BTZ metric in the $(2+1)$-D and a $(1+1)$-D limits of Einstein gravity. The Smarr relation is naturally upheld in both BTZ cases, where those with $Q \

  14. Strains and Jets in Black Hole Fields

    E-Print Network [OSTI]

    D. Bini; F. de Felice; A. Geralico

    2007-12-14

    We study the behaviour of an initially spherical bunch of particles emitted along trajectories parallel to the symmetry axis of a Kerr black hole. We show that, under suitable conditions, curvature and inertial strains compete to generate jet-like structures.

  15. Optical orientation of holes in strained nanostructures

    SciTech Connect (OSTI)

    Averkiev, N. S.; Sablina, N. I.

    2008-03-15

    A theory describing the optical orientation and Hanle effect for holes in quantum wells or quantum dots based on cubic semiconductors is developed. It is demonstrated that the presence of internal or external strain in quantum-confinement heterostructures leads to the dependence of the Hanle effect on the orientation of the magnetic field with respect to the heterostructure growth axis.

  16. Area products for black hole horizons

    E-Print Network [OSTI]

    Visser, Matt

    2013-01-01

    Area products for multi-horizon black holes often have intriguing properties, and are often independent of the mass of the black hole (depending only on various charges, angular momenta, and moduli). Such products are often formulated in terms of the areas of inner (Cauchy) horizons and event horizons, and often include the effects of unphysical "virtual'" horizons. For the Schwarzschild-de Sitter [Kottler] black hole in (3+1) dimensions it is shown by explicit exact calculation that the product of event horizon area and cosmological horizon area is not mass independent. (Including the effect of the third "virtual" horizon does not improve the situation.) Similarly, in the Reissner-Nordstrom-anti-de Sitter black hole in (3+1) dimensions the product of inner (Cauchy) horizon area and event horizon area is calculated (perturbatively), and is shown to be not mass independent. That is, the mass-independence of the product of physical horizon areas is not generic. In the generic situation, whenever the quasi-local...

  17. Trumpet-puncture initial data for black holes

    SciTech Connect (OSTI)

    Immerman, Jason D.; Baumgarte, Thomas W.

    2009-09-15

    We propose a new approach, based on the puncture method, to construct black hole initial data in the so-called trumpet geometry, i.e. on slices that asymptote to a limiting surface of nonzero areal radius. Our approach is easy to implement numerically and, at least for nonspinning black holes, does not require any internal boundary conditions. We present numerical results, obtained with a uniform-grid finite-difference code, for boosted black holes and binary black holes. We also comment on generalizations of this method for spinning black holes.

  18. 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

    2015-01-28

    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.

  19. Thermodynamic Relations for Kiselev and Dilaton Black Hole

    E-Print Network [OSTI]

    Bushra Majeed; Mubasher Jamil; Parthapratim Pradhan

    2015-08-24

    We investigate the thermodynamics and phase transition for Kiselev black hole and dilaton black hole. Speci?cally we consider Reissner Nordstrom black hole surrounded by radiation and dust, and Schwarzschild black hole surrounded by quintessence, as special cases of Kiselev solution. We have calculated the products relating the surface gravities, surface temperatures, Komar energies, areas, entropies, horizon radii and the irreducible masses at the Cauchy and the event horizons. It is observed that the product of surface gravities, surface temperature product and product of Komar energies at the horizons are not universal quantities for the Kiselev solutions while products of areas and entropies at both the horizons are independent of mass of the above mentioned black holes (except for Schwarzschild black hole surrounded by quintessence). For charged dilaton black hole, all the products vanish. First law of thermodynamics is also veri?ed for Kiselev solutions. Heat capacities are calculated and phase transitions are observed, under certain conditions.

  20. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-16

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  1. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Liu, Chang; Wu, Yu-Mei; Zhang, Yu-Hao

    2015-01-01

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  2. Quantization of black holes by analogy with hydrogen atoms

    E-Print Network [OSTI]

    Chang Liu; Yan-Gang Miao; Yu-Mei Wu; Yu-Hao Zhang

    2015-11-23

    We suggest a proposal of quantization for black holes that is based on an analogy between a black hole and a hydrogen atom. A self-regular Schwarzschild-AdS black hole is investigated, where the mass density of the extreme black hole is given by the probability density of the ground state of hydrogen atoms and the mass densities of non-extreme black holes are chosen to be the probability densities of excited states with no angular momenta. Consequently, it is logical to accept quantization of mean radii of hydrogen atoms as that of black hole horizons. In this way, quantization of total black hole masses is deduced. Furthermore, the quantum hoop conjecture and the Correspondence Principle are discussed.

  3. Energy Extraction from Spinning Black Holes via Relativistic Jets

    E-Print Network [OSTI]

    Ramesh Narayan; Jeffrey E. McClintock; Alexander Tchekhovskoy

    2013-03-12

    It has for long been an article of faith among astrophysicists that black hole spin energy is responsible for powering the relativistic jets seen in accreting black holes. Two recent advances have strengthened the case. First, numerical general relativistic magnetohydrodynamic simulations of accreting spinning black holes show that relativistic jets form spontaneously. In at least some cases, there is unambiguous evidence that much of the jet energy comes from the black hole, not the disk. Second, spin parameters of a number of accreting stellar-mass black holes have been measured. For ballistic jets from these systems, it is found that the radio luminosity of the jet correlates with the spin of the black hole. This suggests a causal relationship between black hole spin and jet power, presumably due to a generalized Penrose process.

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

    E-Print Network [OSTI]

    Miroslav Micic; Tom Abel; Steinn Sigurdsson

    2006-09-15

    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.

  5. Rotating analogue black holes: Quasinormal modes and tails, superresonance, and sonic bombs and plants in the draining bathtub acoustic hole

    E-Print Network [OSTI]

    José P. S. Lemos

    2013-12-27

    The analogy between sound wave propagation and light waves led to the study of acoustic holes, the acoustic analogues of black holes. Many black hole features have their counterparts in acoustic holes. The Kerr metric, the rotating metric for black holes in general relativity, has as analogue the draining bathtub metric, a metric for a rotating acoustic hole. Here we report on the progress that has been made in the understanding of features, such as quasinormal modes and tails, superresonance, and instabilities when the hole is surrounded by a reflected mirror, in the draining bathtub metric. Given then the right settings one can build up from these instabilities an apparatus that stores energy in the form of amplified sound waves. This can be put to wicked purposes as in a bomb, or to good profit as in a sonic plant.

  6. Hovering Black Holes from Charged Defects

    E-Print Network [OSTI]

    Gary T. Horowitz; Nabil Iqbal; Jorge E. Santos; Benson Way

    2015-05-05

    We construct the holographic dual of an electrically charged, localised defect in a conformal field theory at strong coupling, by applying a spatially dependent chemical potential. We find that the IR behaviour of the spacetime depends on the spatial falloff of the potential. Moreover, for sufficiently localized defects with large amplitude, we find that a new gravitational phenomenon occurs: a spherical extremal charged black hole nucleates in the bulk: a hovering black hole. This is a second order quantum phase transition. We construct this new phase with several profiles for the chemical potential and study its properties. We find an apparently universal behaviour for the entropy of the defect as a function of its amplitude. We comment on the possible field theory implications of our results.

  7. Astrophysical black holes in screened modified gravity

    SciTech Connect (OSTI)

    Davis, Anne-Christine; Jha, Rahul; Muir, Jessica; Gregory, Ruth E-mail: r.a.w.gregory@durham.ac.uk E-mail: jlmuir@umich.edu

    2014-08-01

    Chameleon, environmentally dependent dilaton, and symmetron gravity are three models of modified gravity in which the effects of the additional scalar degree of freedom are screened in dense environments. They have been extensively studied in laboratory, cosmological, and astrophysical contexts. In this paper, we present a preliminary investigation into whether additional constraints can be provided by studying these scalar fields around black holes. By looking at the properties of a static, spherically symmetric black hole, we find that the presence of a non-uniform matter distribution induces a non-constant scalar profile in chameleon and dilaton, but not necessarily symmetron gravity. An order of magnitude estimate shows that the effects of these profiles on in-falling test particles will be sub-leading compared to gravitational waves and hence observationally challenging to detect.

  8. Laser stabilization using spectral hole burning

    E-Print Network [OSTI]

    L. Rippe; B. Julsgaard; A. Walther; S. Kröll

    2006-11-05

    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.

  9. Black Hole Portal into Hidden Valleys

    E-Print Network [OSTI]

    Sergei Dubovsky; Victor Gorbenko

    2010-12-13

    Superradiant instability turns rotating astrophysical black holes into unique probes of light axions. We consider what happens when a light axion is coupled to a strongly coupled hidden gauge sector. In this case superradiance results in an adiabatic increase of a hidden sector CP-violating $\\theta$-parameter in a near horizon region. This may trigger a first order phase transition in the gauge sector. As a result a significant fraction of a black hole mass is released as a cloud of hidden mesons and can be later converted into electromagnetic radiation. This results in a violent electromagnetic burst. The characteristic frequency of such bursts may range approximately from 100 eV to 100 MeV.

  10. Puncture Evolution of Schwarzschild Black Holes

    E-Print Network [OSTI]

    J. David Brown

    2008-01-15

    The moving puncture method is analyzed for a single, non-spinning black hole. It is shown that the puncture region is not resolved by current numerical codes. As a result, the geometry near the puncture appears to evolve to an infinitely long cylinder of finite areal radius. The puncture itself actually remains at spacelike infinity throughout the evolution. In the limit of infinite resolution the data never become stationary. However, at any reasonable finite resolution the grid points closest to the puncture are rapidly drawn into the black hole interior by the Gamma-driver shift condition. The data can then evolve to a stationary state. These results suggest that the moving puncture technique should be viewed as a type of "natural excision".

  11. The hydraulic jump as a white hole

    E-Print Network [OSTI]

    G. E. Volovik

    2005-10-21

    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.

  12. Hybrid black-hole binary initial data

    E-Print Network [OSTI]

    Bruno C. Mundim; Bernard J. Kelly; Yosef Zlochower; Hiroyuki Nakano; Manuela Campanelli

    2010-12-04

    Traditional black-hole binary puncture initial data is conformally flat. This unphysical assumption is coupled with a lack of radiation signature from the binary's past life. As a result, waveforms extracted from evolutions of this data display an abrupt jump. In Kelly et al. [Class.Quant.Grav.27:114005,2010], a new binary black-hole initial data with radiation contents derived in the post-Newtonian (PN) calculation was adapted to puncture evolutions in numerical relativity. This data satisfies the constraint equations to the 2.5PN order, and contains a transverse-traceless "wavy" metric contribution, violating the standard assumption of conformal flatness. Although the evolution contained less spurious radiation, there were undesired features; the unphysical horizon mass loss and the large initial orbital eccentricity. Introducing a hybrid approach to the initial data evaluation, we significantly reduce these undesired features.

  13. Slant hole completion test. Final report

    SciTech Connect (OSTI)

    Mann, R.L.

    1993-07-01

    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.

  14. Electromagnetic Jets from Stars and Black Holes

    E-Print Network [OSTI]

    Samuel E. Gralla; Alexandru Lupsasca; Maria J. Rodriguez

    2015-04-08

    We present analytic force-free solutions modeling rotating stars and black holes immersed in the magnetic field of a thin disk that terminates at an inner radius. The solutions are exact in flat spacetime and approximate in Kerr spacetime. The compact object produces a conical jet whose properties carry information about its nature. For example, the jet from a star is surrounded by a current sheet, while that of a black hole is smooth. We compute an effective resistance in each case and compare to the canonical values used in circuit models of energy extraction. These solutions illustrate all of the basic features of the Blandford-Znajek process for energy extraction and jet formation in a clean setting.

  15. Electromagnetic Jets from Stars and Black Holes

    E-Print Network [OSTI]

    Gralla, Samuel E; Rodriguez, Maria J

    2015-01-01

    We present analytic force-free solutions modeling rotating stars and black holes immersed in the magnetic field of a thin disk that terminates at an inner radius. The solutions are exact in flat spacetime and approximate in Kerr spacetime. The compact object produces a conical jet whose properties carry information about its nature. For example, the jet from a star is surrounded by a current sheet, while that of a black hole is smooth. We compute an effective resistance in each case and compare to the canonical values used in circuit models of energy extraction. These solutions illustrate all of the basic features of the Blandford-Znajek process for energy extraction and jet formation in a clean setting.

  16. Stable gravastars - an alternative to black holes?

    E-Print Network [OSTI]

    Matt Visser; David L. Wiltshire

    2003-12-04

    The "gravastar" picture developed by Mazur and Mottola is one of a very small number of serious challenges to our usual conception of a "black hole". In the gravastar picture there is effectively a phase transition at/ near where the event horizon would have been expected to form, and the interior of what would have been the black hole is replaced by a segment of de Sitter space. While Mazur and Mottola were able to argue for the thermodynamic stability of their configuration, the question of dynamic stability against spherically symmetric perturbations of the matter or gravity fields remains somewhat obscure. In this article we construct a model that shares the key features of the Mazur-Mottola scenario, and which is sufficiently simple for a full dynamical analysis. We find that there are some physically reasonable equations of state for the transition layer that lead to stability.

  17. Phase Structure of Higher Spin Black Holes

    E-Print Network [OSTI]

    Abhishek Chowdhury; Arunabha Saha

    2015-02-12

    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.

  18. Comparing quantum black holes and naked singularities

    E-Print Network [OSTI]

    T. P. Singh

    2000-12-21

    There are models of gravitational collapse in classical general relativity which admit the formation of naked singularities as well as black holes. These include fluid models as well as models with scalar fields as matter. Even if fluid models were to be regarded as unphysical in their matter content, the remaining class of models (based on scalar fields) generically admit the formation of visible regions of finite but arbitrarily high curvature. Hence it is of interest to ask, from the point of view of astrophysics, as to what a stellar collapse leading to a naked singularity (or to a visible region of very high curvature) will look like, to a far away observer. The emission of energy during such a process may be divided into three phases - (i) the classical phase, during which matter and gravity can both be treated according to the laws of classical physics, (ii) the semiclassical phase, when gravity is treated classically but matter behaves as a quantum field, and (iii) the quantum gravitational phase. In this review, we first give a summary of the status of naked singularities in classical relativity, and then report some recent results comparing the semiclassical phase of black holes with the semiclassical phase of spherical collapse leading to a naked singularity. In particular, we ask how the quantum particle creation during the collapse leading to a naked singularity compares with the Hawking radiation from a star collapsing to form a black hole. It turns out that there is a fundamental difference between the two cases. A spherical naked star emits only about one Planck energy during its semiclassical phase, and the further evolution can only be determined by the laws of quantum gravity. This contrasts with the semiclassical evaporation of a black hole.

  19. Electromagnetic wave scattering by Schwarzschild black holes

    E-Print Network [OSTI]

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

    2009-05-20

    We analyze the scattering of a planar monochromatic electromagnetic wave incident upon a Schwarzschild black hole. We obtain accurate numerical results from the partial wave method for the electromagnetic scattering cross section, and show that they are in excellent agreement with analytical approximations. The scattering of electromagnetic waves is compared with the scattering of scalar, spinor and gravitational waves. We present a unified picture of the scattering of all massless fields for the first time.

  20. Charged Cylindrical Black Holes in Conformal Gravity

    E-Print Network [OSTI]

    Jackson Levi Said; Joseph Sultana; Kristian Zarb Adami

    2013-01-04

    Considering cylindrical topology we present the static solution for a charged black hole in conformal gravity. We show that unlike the general relativistic case there are two different solutions, both including a factor that when set to zero recovers the familiar static charged black string solution in Einstein's theory. This factor gives rise to a linear term in the potential that also features in the neutral case and may have significant ramifications for particle trajectories.

  1. Lagrangian perfect fluids and black hole mechanics

    E-Print Network [OSTI]

    Vivek Iyer

    1996-10-15

    The first law of black hole mechanics (in the form derived by Wald), is expressed in terms of integrals over surfaces, at the horizon and spatial infinity, of a stationary, axisymmetric black hole, in a diffeomorphism invariant Lagrangian theory of gravity. The original statement of the first law given by Bardeen, Carter and Hawking for an Einstein-perfect fluid system contained, in addition, volume integrals of the fluid fields, over a spacelike slice stretching between these two surfaces. When applied to the Einstein-perfect fluid system, however, Wald's methods yield restricted results. The reason is that the fluid fields in the Lagrangian of a gravitating perfect fluid are typically nonstationary. We therefore first derive a first law-like relation for an arbitrary Lagrangian metric theory of gravity coupled to arbitrary Lagrangian matter fields, requiring only that the metric field be stationary. This relation includes a volume integral of matter fields over a spacelike slice between the black hole horizon and spatial infinity, and reduces to the first law originally derived by Bardeen, Carter and Hawking when the theory is general relativity coupled to a perfect fluid. We also consider a specific Lagrangian formulation for an isentropic perfect fluid given by Carter, and directly apply Wald's analysis. The resulting first law contains only surface integrals at the black hole horizon and spatial infinity, but this relation is much more restrictive in its allowed fluid configurations and perturbations than that given by Bardeen, Carter and Hawking. In the Appendix, we use the symplectic structure of the Einstein-perfect fluid system to derive a conserved current for perturbations of this system: this current reduces to one derived ab initio for this system by Chandrasekhar and Ferrari.

  2. Big Bang Nucleosynthesis and Primordial Black Holes

    E-Print Network [OSTI]

    C. Sivaram; Kenath Arun

    2010-06-28

    There are ongoing efforts in detecting Hawking radiation from primordial black holes (PBH) formed during the early universe. Here we put an upper limit on the PBH number density that could have been formed prior to the big bang nucleosynthesis era, based on the constraint that the PBH evaporation energy consisting of high energy radiation not affect the observed abundances' of elements, by disintegrating the nuclei.

  3. Thermodynamics and Luminosities of Rainbow Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-07-14

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As a result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is \\textquotedblleft Gravity's rainbow", where the spacetime background felt by a test particle would depend on its energy. Focusing on the \\textquotedblleft Amelino-Camelia dispersion relation" which is $E^{2}=m^{2}+p^{2}\\left[ 1-\\eta\\left( E/m_{p}\\right) ^{n}\\right] $ with $n>0$, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of $\\eta$ and $n$ in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with $\\eta<0$ and $n\\geq2$. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute luminosities of a 2D black hole, a Schwarzschild one and a static uncharged black string. It is found that the luminosities can be significantly suppressed or boosted depending on the values of $\\eta$ and $n$.

  4. Rotating black hole solutions with quintessential energy

    E-Print Network [OSTI]

    Toshmatov, Bobir; Ahmedov, Bobomurat

    2015-01-01

    Quintessential dark energy with density $\\rho$ and pressure $p$ is governed by an equation of state of the form $p=-\\omega_{q}\\rho$ with the quintessential parameter $\\omega_q\\in(-1;-1/3)$. We derive the geometry of quintessential rotating black holes, generalizing thus the Kerr spacetimes. Then we study the quintessential rotating black hole spacetimes with the special value of $\\omega_q = -2/3$ when the resulting formulae are simple and easily tractable. We show that such special spacetimes can exist for dimensionless quintessential parameter $c<1/6$ and determine the critical rotational parameter $a_0$ separating the black hole and naked singularity spacetime in dependence on the quintessential parameter $c$. For the spacetimes with $\\omega_q = 2/3$ we present the integrated geodesic equations in separated form and study in details the circular geodetical orbits. We give radii and parameters of the photon circular orbits, marginally bound and marginally stable orbits. We stress that the outer boundary o...

  5. Adaptive Finite Elements and Colliding Black Holes

    E-Print Network [OSTI]

    Douglas N. Arnold; Arup Mukherjee; Luc Pouly

    1997-09-15

    According to the theory of general relativity, the relative acceleration of masses generates gravitational radiation. Although gravitational radiation has not yet been detected, it is believed that extremely violent cosmic events, such as the collision of black holes, should generate gravity waves of sufficient amplitude to detect on earth. The massive Laser Interferometer Gravitational-wave Observatory, or LIGO, is now being constructed to detect gravity waves. Consequently there is great interest in the computer simulation of black hole collisions and similar events, based on the numerical solution of the Einstein field equations. In this note we introduce the scientific, mathematical, and computational problems and discuss the development of a computer code to solve the initial data problem for colliding black holes, a nonlinear elliptic boundary value problem posed in an unbounded three dimensional domain which is a key step in solving the full field equations. The code is based on finite elements, adaptive meshes, and a multigrid solution process. Here we will particularly emphasize the mathematical and algorithmic issues arising in the generation of adaptive tetrahedral meshes.

  6. Probing Dark Energy with Black Hole Binaries

    E-Print Network [OSTI]

    Laura Mersini-Houghton; Adam Kelleher

    2008-08-25

    The equation of state (EoS) of dark energy $w$ remains elusive despite enormous experimental efforts to pin down its value and its time variation. Yet it is the single most important handle we have in our understanding of one of the most mysterious puzzle in nature, dark energy. This letter proposes a new method for measuring the EoS of dark energy by using the gravitational waves (GW) of black hole binaries. The method described here offers an alternative to the standard way of large scale surveys. It is well known that the mass of a black hole changes due to the accretion of dark energy but at an extremely slow rate. However, a binary of supermassive black holes (SBH) radiates gravitational waves with a power proportional to the masses of these accreting stars and thereby carries information on dark energy. These waves can propagate through the vastness of structure in the universe unimpeded. The orbital changes of the binary, induced by the energy loss from gravitational radiation, receive a large contribution from dark energy accretion. This contribution is directly proportional to $(1+w)$ and is dominant for SBH binaries with separation $R \\ge 1000$ parsec, thereby accelerating the merging process for $w > -1$ or ripping the stars apart for phantom dark energy with $w < -1$. Such orbital changes, therefore $w$, can be detected with LIGO and LISA near merging time, or with X-ray and radio measurements of Chandra and VLBA experiments.

  7. Accretion Processes On a Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-05-03

    We describe astrophysical processes around a black hole keeping primarily the physics of accretion in mind. In Section 1, we briefly discuss the formation, evolution and detection of black holes. We also discuss the difference of flow properties around a black hole and a Newtonian star. In Section 2, we present past and present developments in the study of spherically accreting flows. We study the properties of Bondi flow with and without radiative transfer. In the presence of significant angular momentum, which is especially true in a binary system, matter will be accreted as a thin Keplerian disk. In Section 3, we discuss a large number of models of these disks including the more popular standard disk model. We present magnetized disk models as well. Since the angular momentum is high in these systems, rotational motion is the most dominant component compared to the radial or the vertical velocity components. In Section 4, we study thick disk models which are of low angular momentum but still have no significant radial motion. The accretion rates could be very high causing the flow to become radiation dominated and the disk to be geometrically thick. For low accretion rates, ion pressure supported disks are formed. In Section 5, we extensively discuss the properties of transonic flows which has with sub-Keplerian angular momentum. In the absence of shock discontinuities, these sub-Keplerian flows are basically advecting, similar to Bondi flows, close to the black holes, though far away they match Keplerian or sub-Keplerian disks. In presence of shocks, the post-shock flow becomes rotation dominated similar to thick disks. In Section 6, we present results of important numerical simulations of accretion flows. Significant results from the studies of evolution of viscous transonic flows are reported. In Section 7, we discuss some observational evidences of the black hole accretion. We also present a detailed model of a generalized accretion disk and present its spectra and compare with observations. In Section 8, we summarize the review and make concluding remarks.

  8. Thermodynamic Product Formula for Taub-NUT Black Hole

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2015-08-20

    We derive various important thermodynamic relations of the inner and outer horizon in the background of Taub-NUT(Newman-Unti-Tamburino) black hole in four dimensional \\emph{Lorentzian geometry}. We compare these properties with the properties of Reissner Nordstr{\\o}m black hole. We compute \\emph{area product, area sum, area minus and area division} of black hole horizons. We show that they all are not universal quantities. Based on these relations, we compute the area bound of all horizons. From area bound, we derive entropy bound and irreducible mass bound for both the horizons. We further study the stability of such black hole by computing the specific heat for both the horizons. It is shown that due to negative specific heat the black hole is thermodynamically unstable. All these calculations might be helpful to understanding the nature of black hole entropy both \\emph{interior} and exterior at the microscopic level.

  9. Thermodynamic Product Formula for Taub-NUT Black Hole

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2015-01-01

    We derive various important thermodynamic relations of the inner and outer horizon in the background of Taub-NUT(Newman-Unti-Tamburino) black hole in four dimensional \\emph{Lorentzian geometry}. We compare these properties with the properties of Reissner Nordstr{\\o}m black hole. We compute \\emph{area product, area sum, area minus and area division} of black hole horizons. We show that they all are not universal quantities. Based on these relations, we compute the area bound of all horizons. From area bound, we derive entropy bound and irreducible mass bound for both the horizons. We further study the stability of such black hole by computing the specific heat for both the horizons. It is shown that due to negative specific heat the black hole is thermodynamically unstable. All these calculations might be helpful to understanding the nature of black hole entropy both \\emph{interior} and exterior at the microscopic level.

  10. Destroying Kerr-Sen black holes with test particles

    E-Print Network [OSTI]

    Haryanto M. Siahaan

    2015-12-05

    By neglecting the self-force, self-energy, and radiative effects, it has been shown that an extremal or near-extremal Kerr-Newman black hole can turn to a naked singularity when it captures charged massive test particles with angular momentum. A straightforward question then arises, do charged and rotating black holes in string theory possess the same property? In this paper we adopt the Wald's gedanken experiment in an effort to destroy a Kerr-Newman black hole's horizon to the case of (near)-extremal Kerr-Sen black holes. We find that feeding a test particle into a (near)-extremal Kerr-Sen black hole could lead to a violation of the extremal bound for such black hole.

  11. Articles which include chevron film cooling holes, and related processes

    DOE Patents [OSTI]

    Bunker, Ronald Scott; Lacy, Benjamin Paul

    2014-12-09

    An article is described, including an inner surface which can be exposed to a first fluid; an inlet; and an outer surface spaced from the inner surface, which can be exposed to a hotter second fluid. The article further includes at least one row or other pattern of passage holes. Each passage hole includes an inlet bore extending through the substrate from the inlet at the inner surface to a passage hole-exit proximate to the outer surface, with the inlet bore terminating in a chevron outlet adjacent the hole-exit. The chevron outlet includes a pair of wing troughs having a common surface region between them. The common surface region includes a valley which is adjacent the hole-exit; and a plateau adjacent the valley. The article can be an airfoil. Related methods for preparing the passage holes are also described.

  12. Thermodynamics of Charged Lovelock - AdS Black Holes

    E-Print Network [OSTI]

    Prasobh C. B.; Jishnu Suresh; V. C. Kuriakose

    2015-10-16

    We investigate the thermodynamic behavior of maximally symmetric charged, asymptotically AdS black hole solutions of Lovelock gravity. We explore the thermodynamic stability of such solutions by the ordinary method of calculating the specific heat of the black holes and investigating its divergences which signal second order phase transitions between black hole states. We then utilize the methods of thermodynamic geometry of black hole spacetimes in order to explain the origin of these points of divergence. We calculate the curvature scalar corresponding to a Legendre-invariant thermodynamic metric of these spacetimes and find that the divergences in the black hole specific heat correspond to singularities in the thermodynamic phase space. We also calculate the area spectrum for large black holes in the model by applying the Bohr-Sommerfeld quantization to the adiabatic invariant calculated for the spacetime.

  13. Galaxy bulges and their massive black holes: a review

    E-Print Network [OSTI]

    Alister W. Graham

    2015-02-17

    With references to both key and oft-forgotten pioneering works, this article starts by presenting a review into how we came to believe in the existence of massive black holes at the centres of galaxies. It then presents the historical development of the near-linear (black hole)-(host spheroid) mass relation, before explaining why this has recently been dramatically revised. Past disagreement over the slope of the (black hole)-(velocity dispersion) relation is also explained, and the discovery of sub-structure within the (black hole)-(velocity dispersion) diagram is discussed. As the search for the fundamental connection between massive black holes and their host galaxies continues, the competing array of additional black hole mass scaling relations for samples of predominantly inactive galaxies are presented.

  14. Method and apparatus of assessing down-hole drilling conditions

    DOE Patents [OSTI]

    Hall, David R. (Provo, UT); Pixton, David S. (Lehl, UT); Johnson, Monte L. (Orem, UT); Bartholomew, David B. (Springville, UT); Fox, Joe (Spanish Fork, UT)

    2007-04-24

    A method and apparatus for use in assessing down-hole drilling conditions are disclosed. The apparatus includes a drill string, a plurality of sensors, a computing device, and a down-hole network. The sensors are distributed along the length of the drill string and are capable of sensing localized down-hole conditions while drilling. The computing device is coupled to at least one sensor of the plurality of sensors. The data is transmitted from the sensors to the computing device over the down-hole network. The computing device analyzes data output by the sensors and representative of the sensed localized conditions to assess the down-hole drilling conditions. The method includes sensing localized drilling conditions at a plurality of points distributed along the length of a drill string during drilling operations; transmitting data representative of the sensed localized conditions to a predetermined location; and analyzing the transmitted data to assess the down-hole drilling conditions.

  15. Proceedings of the Second International Symposium on Dynamics of Fluids in Fractured Rock

    E-Print Network [OSTI]

    Faybishenko, Boris; Witherspoon, Paul A.

    2004-01-01

    Soultz Boreholes The Soultz project is a geothermal Hot-Dry-geothermal field, 56 wells, including slim holes and production boreholes,of boreholes and cross-sections. The geothermal fluid flow

  16. A Quantum Material Model of Static Schwarzschild Black Holes

    E-Print Network [OSTI]

    S. -T. Sung

    1997-03-16

    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.

  17. Classical and Quantum Properties of Liouville Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1994-04-25

    Black hole spacetimes can arise when a Liouville field is coupled to two- dimensional gravity. Exact solutions are obtained both classically and when quantum corrections due to back reaction effects are included. The black hole temperature depends upon the mass and the thermodynamic limit breaks down before evaporation of the black hole is complete, indicating that higher-loop effects must be included for a full description of the process.

  18. A Variational Principle for Asymptotically Randall-Sundrum Black Holes

    E-Print Network [OSTI]

    Scott Fraser; Douglas M. Eardley

    2015-07-28

    We prove the following variational principle for asymptotically Randall-Sundrum (RS) black holes, based on the first law of black hole mechanics: Instantaneously static initial data that extremizes the mass yields a static black hole, for variations at fixed apparent horizon area, AdS curvature length, cosmological constant, brane tensions, and RS brane warp factors. This variational principle is valid with either two branes (RS1) or one brane (RS2), and is applicable to variational trial solutions.

  19. Optoelectronic device with nanoparticle embedded hole injection/transport layer

    SciTech Connect (OSTI)

    Wang, Qingwu; Li, Wenguang; Jiang, Hua

    2012-01-03

    An optoelectronic device is disclosed that can function as an emitter of optical radiation, such as a light-emitting diode (LED), or as a photovoltaic (PV) device that can be used to convert optical radiation into electrical current, such as a photovoltaic solar cell. The optoelectronic device comprises an anode, a hole injection/transport layer, an active layer, and a cathode, where the hole injection/transport layer includes transparent conductive nanoparticles in a hole transport material.

  20. Thermal Fluctuations in a Charged AdS Black Hole

    E-Print Network [OSTI]

    Pourhassan, B

    2015-01-01

    In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.

  1. Thermal Fluctuations in a Charged AdS Black Hole

    E-Print Network [OSTI]

    B. Pourhassan; Mir Faizal

    2015-08-12

    In this paper, we will analyze the effects of thermal fluctuations on a charged AdS black hole. This will be done by analyzing the corrections to black hole thermodynamics due to these thermal fluctuations. We will demonstrate that the entropy of this black hole get corrected by logarithmic term. We will also calculate other corrections to other important thermodynamic quantities for this black hole. Finally, we will use the corrected value of the specific heat to analyze the phase transition in this system.

  2. Thermal Gradient Holes At Breitenbush Hot Springs Area (Ingebritsen...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Breitenbush Hot Springs Area (Ingebritsen, Et Al., 1993) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  3. Thermal Gradient Holes At Neal Hot Springs Geothermal Area (U...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Neal Hot Springs Geothermal Area (U.S. Geothermal Inc., 2010) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  4. Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff & Bowers, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  5. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Long Valley Caldera Geothermal Area (Sorey, Et Al., 1978) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  6. Moduli Vacuum Bubbles Produced by Evaporating Black Holes

    E-Print Network [OSTI]

    J. R. Morris

    2007-08-14

    We consider a model with a toroidally compactified extra dimension giving rise to a temperature-dependent 4d effective potential with one-loop contributions due to the Casimir effect, along with a 5d cosmological constant. The forms of the effective potential at low and high temperatures indicates a possibility for the formation of a domain wall bubble, formed by the modulus scalar field, surrounding an evaporating black hole. This is viewed as an example of a recently proposed black hole vacuum bubble arising from matter-sourced moduli fields in the vicinity of an evaporating black hole [D. Green, E. Silverstein, and D. Starr, Phys. Rev. D74, 024004 (2006), arXiv:hep-th/0605047]. The black hole bubble can be highly opaque to lower energy particles and photons, and thereby entrap them within. For high temperature black holes, there may also be a symmetry-breaking black hole bubble of false vacuum of the type previously conjectured by Moss [I.G. Moss, Phys. Rev. D32,1333 (1985)], tending to reflect low energy particles from its wall. A double bubble composed of these two different types of bubble may form around the black hole, altering the hole's emission spectrum that reaches outside observers. Smaller mass black holes that have already evaporated away could have left vacuum bubbles behind that contribute to the dark matter.

  7. Compound and Elemental Analysis At Seven Mile Hole Area (Larson...

    Open Energy Info (EERE)

    Of Older Hot Spring Alteration In Sevenmile Hole, Grand Canyon Of The Yellowstone River, Yellowstone Caldera, Wyoming Additional References Retrieved from "http:en.openei.orgw...

  8. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Long Valley Caldera Geothermal Area (Conservation, 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  9. Thermal Gradient Holes At Long Valley Caldera Geothermal Area...

    Open Energy Info (EERE)

    Area (Farrar, Et Al., 2003) Exploration Activity Details Location Long Valley Caldera Geothermal Area Exploration Technique Thermal Gradient Holes Activity Date 1998 - 2002...

  10. Hydrodynamic model for electron-hole plasma in graphene

    E-Print Network [OSTI]

    D. Svintsov; V. Vyurkov; S. Yurchenko; T. Otsuji; V. Ryzhii

    2012-01-03

    We propose a hydrodynamic model describing steady-state and dynamic electron and hole transport properties of graphene structures which accounts for the features of the electron and hole spectra. It is intended for electron-hole plasma in graphene characterized by high rate of intercarrier scattering compared to external scattering (on phonons and impurities), i.e., for intrinsic or optically pumped (bipolar plasma), and gated graphene (virtually monopolar plasma). We demonstrate that the effect of strong interaction of electrons and holes on their transport can be treated as a viscous friction between the electron and hole components. We apply the developed model for the calculations of the graphene dc conductivity, in particular, the effect of mutual drag of electrons and holes is described. The spectra and damping of collective excitations in graphene in the bipolar and monopolar limits are found. It is shown that at high gate voltages and, hence, at high electron and low hole densities (or vice-versa), the excitations are associated with the self-consistent electric field and the hydrodynamic pressure (plasma waves). In intrinsic and optically pumped graphene, the waves constitute quasineutral perturbations of the electron and hole densities (electron-hole sound waves) with the velocity being dependent only on the fundamental graphene constants.

  11. Lovelock black hole thermodynamics in a string cloud model

    E-Print Network [OSTI]

    Lee, Tae-Hun; Maharaj, Sunil D; Baboolal, Dharmanand

    2015-01-01

    The Lovelock theory is an extension of general relativity to higher dimensions. We study the Lovelock black hole for a string cloud model in arbitrary dimensional spacetime, and in turn also analyze its thermodynamical properties. Indeed, we compute the mass, temperature and entropy of the black hole and also perform a thermodynamical stability analysis. The phase structure suggests that the Hawking-Page phase transition is achievable. It turns out that the presence of the Lovelock terms and/or background string cloud completely changes the black hole thermodynamics. Interestingly, the entropy of a black hole is unaffected due to a background string cloud, but has a correction term due to Lovelock gravity.

  12. Thermodynamics of rotating black holes in conformal gravity

    E-Print Network [OSTI]

    Kamvar, Negin; Soroushfar, Saheb

    2015-01-01

    In this paper we consider a metric of a rotating black hole in conformal gravity. We calculate the thermodynamical quantities for this rotating black hole including Hawking temperature and entropy in four dimensional space-time, as we obtain the effective value of Komar angular momentum. The result is valid on the event horizon of the black hole, and at any radial distance out of it. Also we verify that the first law of thermodynamics will be held for this type of black hole.

  13. Particle-Hole Optical Model: Fantasy or Reality?

    E-Print Network [OSTI]

    M. H. Urin

    2010-05-13

    An attempt to formulate the optical model of particle-hole-type excitations (including giant resonances) is undertaken. The model is based on the Bethe--Goldstone equation for the particle-hole Green function. This equation involves a specific energy-dependent particle-hole interaction that is due to virtual excitation of many-quasiparticle configurations and responsible for the spreading effect. After energy averaging, this interaction involves an imaginary part. The analogy between the single-quasiparticle and particle-hole optical models is outlined.

  14. Ultrafast Core-Hole Induced Dynamics in Water

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

    is essential for many diverse fields, from condensed matter physics to medicine to environmental science. An incoming photon with enough energy to produce a core hole in a...

  15. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Benrong Mu; Peng Wang; Haitang Yang

    2015-01-24

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  16. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    In this paper, we investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole's mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  17. Energy Distribution of a Charged Regular Black Hole

    E-Print Network [OSTI]

    Irina Radinschi

    2000-11-20

    We calculate the energy distribution of a charged regular black hole by using the energy-momentum complexes of Einstein and M{\\o}ller.

  18. Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank & Niggemann, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal...

  19. Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Blue Mountain Geothermal Area (Fairbank & Ross, 1999) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient...

  20. Thermal Gradient Holes At Lightning Dock Geothermal Area (Cunniff...

    Open Energy Info (EERE)

    holes drilled References R.A. Cunniff, R.L. Bowers (2003) Final Report: Enhanced Geothermal Systems Technology Phase II: Animas Valley, New Mexico Additional References...

  1. Thermal Gradient Holes At Walker-Lane Transitional Zone Region...

    Open Energy Info (EERE)

    Zone Region (Pritchett, 2004) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Thermal Gradient Holes Activity Date...

  2. Free fall onto evaporating black holes at the quantum limit

    E-Print Network [OSTI]

    Maurice H. P. M. van Putten

    2015-11-11

    Black hole space times evaporate in discrete steps due to remarkably slow Hawking radiation. We here identify evaporation with essentially extremal states at the limit of quantum computation, performing $2.7\\times 10^{79}$ bit calculations per photon emission in a one solar mass black hole. During evaporation, particles in free fall co-evolve satisfying $EM=$constant, where $E$ and $M$ denote the total mass energy-at-infinity of the particle and, respectively, black hole. Particles are hereby increasingly entangled with the black hole space-time over the course of its evaporation.

  3. Thermal Gradient Holes At Central Nevada Seismic Zone Region...

    Open Energy Info (EERE)

    Thermal Gradient Holes At Central Nevada Seismic Zone Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Thermal Gradient...

  4. The effects of fastener hole defects 

    E-Print Network [OSTI]

    Andrews, Scot D.

    1991-01-01

    ) 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...

  5. Collective Excitations in Electron-Hole Bilayers

    SciTech Connect (OSTI)

    Kalman, G. J. [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Hartmann, P.; Donko, Z. [Research Institute for Solid State Physics and Optics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Golden, K. I. [Department of Mathematics and Statistics and Department of Physics, University of Vermont, Burlington, Vermont 05401 (United States)

    2007-06-08

    We report a combined analytic and molecular dynamics analysis of the collective mode spectrum of a bipolar (electron-hole) bilayer in the strong coupling classical limit. A robust, isotropic energy gap is identified in the out-of-phase spectra, generated by the combined effect of correlations and of the excitation of the bound dipoles. In the in-phase spectra we identify longitudinal and transverse acoustic modes wholly maintained by correlations. Strong nonlinear generation of higher harmonics of the fundamental dipole oscillation frequency and the transfer of harmonics between different modes is observed.

  6. Neutron Hole States of Mo-99 

    E-Print Network [OSTI]

    Bindal, P. K.; Youngblood, David H.; Kozub, R. L.; Hoffmannpinther, P. H.

    1975-01-01

    V; measured o(0), 99Mo levels, deduced l, S; calculated J, 7(, 8, particle-core-coupling model. I. INTRODUCTION II. EXPERIMENTAL PROCEDURE AND RESULTS Recent studies of proton and neutron configura- tions of odd-A nuclei in the mass region of 90?100 have... of "'"'"Nb was obtained' ' using a quasiparticle core coupling model. Also, study of the ~'Mo(P, d)~Mo reaction' revealed three distinct groups of weakly excited neutron hole states, one corresponding to an l = 4 transf er and two corresponding...

  7. Down-hole periodic seismic generator

    DOE Patents [OSTI]

    Hardee, H.C.; Hills, R.G.; Striker, R.P.

    1982-10-28

    A down hole periodic seismic generator system is disclosed 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.

  8. The static and dynamic characteristics of divergent tapered-bore hole-pattern gas seals 

    E-Print Network [OSTI]

    Carter, Jeremy John

    2001-01-01

    Experimental data is presented for three hole-pattern annular gas seals with differing diverging tapers machined in them. The holes are approximately 3.12 mm (.123 in) deep on average with a hole area to surface area ratio ...

  9. Hadrons As Kerr-Newman Black Holes

    E-Print Network [OSTI]

    R. L. Oldershaw

    2010-03-15

    The scale invariance of the source-free Einstein field equations suggests that one might be able to model hadrons as "strong gravity" black holes, if one uses an appropriate rescaling of units or a revised gravitational coupling factor. The inner consistency of this hypothesis is tested by retrodicting a close approximation to the mass of the proton from an equation that relates the angular momentum and mass of a Kerr black hole. More accurate mass and radius values for the proton are then retrodicted using the geometrodynamics form of the full Kerr-Newman solution of the Einstein-Maxwell equations. The radius of an alpha particle is calculated as an additional retrodictive test. In a third retrodictive test of the "strong gravity" hypothesis, the subatomic particle mass spectrum in the 100 MeV to 7,000 MeV range is retrodicted to a first approximation using the Kerr solution of General Relativity. The particle masses appear to form a restricted set of quantized values of the Kerr solution: n^1/2 M, where values of n are a set of discrete integers and M is the revised Planck mass. The accuracy of the 27 retrodicted masses averages 98.4%. Finally, the new atomic scale gravitational coupling constant suggests a radical revision of the assumptions governing the Planck scale, and leads to a natural explanation for the fine structure constant.

  10. Probing the puncture for black hole simulations

    E-Print Network [OSTI]

    J. David Brown

    2009-10-23

    With the puncture method for black hole simulations, the second infinity of a wormhole geometry is compactified to a single "puncture point" on the computational grid. The region surrounding the puncture quickly evolves to a trumpet geometry. The computational grid covers only a portion of the trumpet throat. It ends at a boundary whose location depends on resolution. This raises the possibility that perturbations in the trumpet geometry could propagate down the trumpet throat, reflect from the puncture boundary, and return to the black hole exterior with a resolution--dependent time delay. Such pathological behavior is not observed. This is explained by the observation that some perturbative modes propagate in the conformal geometry, others propagate in the physical geometry. The puncture boundary exists only in the physical geometry. The modes that propagate in the physical geometry are always directed away from the computational domain at the puncture boundary. The finite difference stencils ensure that these modes are advected through the boundary with no coupling to the modes that propagate in the conformal geometry. These results are supported by numerical experiments with a code that evolves spherically symmetric gravitational fields with standard Cartesian finite difference stencils. The code uses the Baumgarte--Shapiro--Shibata--Nakamura formulation of Einstein's equations with 1+log slicing and gamma--driver shift conditions.

  11. Thermodynamics and Luminosities of Rainbow Black Holes

    E-Print Network [OSTI]

    Mu, Benrong; Yang, Haitang

    2015-01-01

    Doubly special relativity (DSR) is an effective model for encoding quantum gravity in flat spacetime. As a result of the nonlinearity of the Lorentz transformation, the energy-momentum dispersion relation is modified. One simple way to import DSR to curved spacetime is \\textquotedblleft Gravity's rainbow", where the spacetime background felt by a test particle would depend on its energy. Focusing on the \\textquotedblleft Amelino-Camelia dispersion relation" which is $E^{2}=m^{2}+p^{2}\\left[ 1-\\eta\\left( E/m_{p}\\right) ^{n}\\right] $ with $n>0$, we investigate the thermodynamical properties of a Schwarzschild black hole and a static uncharged black string for all possible values of $\\eta$ and $n$ in the framework of rainbow gravity. It shows that there are non-vanishing minimum masses for these two black holes in the cases with $\\eta<0$ and $n\\geq2$. Considering effects of rainbow gravity on both the Hawking temperature and radius of the event horizon, we use the geometric optics approximation to compute lum...

  12. Extremal Limits of Rotating Black Holes

    E-Print Network [OSTI]

    Laura Andrianopoli; Riccardo D'Auria; Antonio Gallerati; Mario Trigiante

    2013-05-30

    We consider non-extremal, stationary, axion-dilaton solutions to ungauged symmetric supergravity models, obtained by Harrison transformations of the non-extremal Kerr solution. We define a general algebraic procedure, which can be viewed as an Inonu-Wigner contraction of the Noether charge matrix associated with the effective D=3 sigma-model description of the solution, yielding, through different singular limits, the known BPS and non-BPS extremal black holes (which include the under-rotating non-BPS one). The non-extremal black hole can thus be thought of as "interpolating" among these limit-solutions. The algebraic procedure that we define generalizes the known Rasheed-Larsen limit which yielded, in the Kaluza-Klein theory, the first instance of under-rotating extremal solution. As an example of our general result, we discuss in detail the non-extremal solution in the T^3-model, with either (q_0, p^1) or (p^0, q_1) charges switched on, and its singular limits. Such solutions, computed in D=3 through the solution-generating technique, is completely described in terms of D=4 fields, which include the fully integrated vector fields.

  13. Exact quasinormal modes for a special class of black holes

    E-Print Network [OSTI]

    Julio Oliva; Ricardo Troncoso

    2010-03-11

    Analytic exact expressions for the quasinormal modes of scalar and electromagnetic perturbations around a special class of black holes are found in d\\ge3 dimensions. It is shown that, the size of the black hole provides a bound for the angular momentum of the perturbation. Quasinormal modes appear when this bound is fulfilled, otherwise the excitations become purely damped.

  14. Modified Black Hole with Polar Jet and Vortex

    E-Print Network [OSTI]

    T. Tmmalm

    2001-12-06

    There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

  15. Pair Production of Topological anti de Sitter Black Holes

    E-Print Network [OSTI]

    R. B. Mann

    1996-07-28

    The pair creation of black holes with event horizons of non-trivial topology is described. The spacetimes are all limiting cases of the cosmological $C$ metric. They are generalizations of the $(2+1)$ dimensional black hole and have asymptotically anti de Sitter behaviour. Domain walls instantons can mediate their pair creation for a wide range of mass and charge.

  16. Analysis of spherically symmetric black holes in Braneworld models

    E-Print Network [OSTI]

    A. B. Pavan

    2010-05-25

    Research on black holes and their physical proprieties has been active on last 90 years. With the appearance of the String Theory and the Braneworld models as alternative descriptions of our Universe, the interest on black holes, in these context, increased. In this work we studied black holes in Braneworld models. A class of spherically symmetric black holes is investigaded as well its stability under general perturbations. Thermodynamic proprieties and quasi-normal modes are discussed. The black holes studied are the SM (zero mass) and CFM solutions, obtained by Casadio {\\it et al.} and Bronnikov {\\it et al.}. The geometry of bulk is unknown. However the Campbell-Magaard Theorem guarantees the existence of a 5-dimensional solution in the bulk whose projection on the brane is the class of black holes considered. They are stable under scalar perturbations. Quasi-normal modes were observed in both models. The tail behavior of the perturbations is the same. The entropy upper bound of a body absorved by the black holes studied was calculated. This limit turned out to be independent of the black hole parameters.

  17. Perturbative Approach to the Quasinormal Modes of Dirty Black Holes

    E-Print Network [OSTI]

    P. T. Leung; Y. T. Liu; W. -M. Suen; C. Y. Tam; K. Young

    1999-03-08

    Using a recently developed perturbation theory for uasinormal modes (QNM's), we evaluate the shifts in the real and imaginary parts of the QNM frequencies due to a quasi-static perturbation of the black hole spacetime. We show the perturbed QNM spectrum of a black hole can have interesting features using a simple model based on the scalar wave equation.

  18. Accretion onto the First Stellar Mass Black Holes

    E-Print Network [OSTI]

    Marcelo A. Alvarez; John H. Wise; Tom Abel

    2008-11-07

    The first stars in the universe, forming at redshifts z>15 in minihalos with masses of order 10^6 Msun, may leave behind black holes as their remnants. These objects could conceivably serve as "seeds" for much larger black holes observed at redshifts z~6. We study the growth of the remnant black holes through accretion including for the first time the emitted accretion radiation with adaptive mesh refinement cosmological radiation-hydrodynamical simulations. The effects of photo-ionization and heating dramatically affect the accretion flow from large scales, resulting in negligible mass growth of the black hole. We compare cases with the accretion luminosity included and neglected to show that the accretion radiation drastically changes the environment within 100 pc of the black hole, where gas temperatures are increased by an order of magnitude. The gas densities are reduced and further star formation in the same minihalo prevented for the two hundred million years of evolution we followed. These calculations show that even without the radiative feedback included most seed black holes do not gain mass as efficiently as has been hoped for in previous theories, implying that black hole remnants of Pop III stars that formed in minihalos are not likely to be the origin of miniquasars. Most importantly, however, these calculations demonstrate that if early stellar mass black holes are indeed accreting close to the Bondi-Hoyle rate with ten percent efficiency they have a dramatic local effect in regulating star formation in the first galaxies.

  19. Filing Holes in Complex Surfaces Using Volumetric Diffusion

    E-Print Network [OSTI]

    Kazhdan, Michael

    components (red) ­ Accurate filling requires knowledge of surface topology #12;Complications of Hole Filling components ­ Complex hole geometry Construction of an arbitrary mesh can result in non-manifold surface ­ Results of subsequent iterations are combined using a variation of alpha blending d0, v0=ds ,[ws0] di

  20. Large rotating AdS black holes from fluid mechanics

    E-Print Network [OSTI]

    Sayantani Bhattacharyya; Subhaneil Lahiri; R. Loganayagam; Shiraz Minwalla

    2008-07-25

    We use the AdS/CFT correspondence to argue that large rotating black holes in global AdS(D) spaces are dual to stationary solutions of the relativistic Navier-Stokes equations on S**(D-2). Reading off the equation of state of this fluid from the thermodynamics of non-rotating black holes, we proceed to construct the nonlinear spinning solutions of fluid mechanics that are dual to rotating black holes. In all known examples, the thermodynamics and the local stress tensor of our solutions are in precise agreement with the thermodynamics and boundary stress tensor of the spinning black holes. Our fluid dynamical description applies to large non-extremal black holes as well as a class of large non-supersymmetric extremal black holes, but is never valid for supersymmetric black holes. Our results yield predictions for the thermodynamics of all large black holes in all theories of gravity on AdS spaces, for example, string theory on AdS(5) x S**5 and M theory on AdS(4) x S**7 and AdS(7) x S**4.

  1. Electric Charge in Interaction with Magnetically Charged Black Holes

    E-Print Network [OSTI]

    J. H. Kim; Sei-Hoon Moon

    2007-10-02

    We examine the angular momentum of an electric charge e placed at rest outside a dilaton black hole with magnetic charge Q. The electromagnetic angular momentum which is stored in the electromagnetic field outside the black hole shows several common features regardless of the dilaton coupling strength, though the dilaton black holes are drastically different in their spacetime structure depending on it. First, the electromagnetic angular momentum depends on the separation distance between the two objects and changes monotonically from eQ to 0 as the charge goes down from infinity to the horizon, if rotational effects of the black hole are discarded. Next, as the black hole approaches extremality, however, the electromagnetic angular momentum tends to be independent of the distance between the two objects. It is then precisely $eQ$ as in the electric charge and monopole system in flat spacetime. We discuss why these effects are exhibited and argue that the above features are to hold in widely generic settings including black hole solutions in theories with more complicated field contents, by addressing the no hair theorem for black holes and the phenomenon of field expulsion exhibited by extremal black holes.

  2. A note on regular black holes in a brane world

    E-Print Network [OSTI]

    Neves, J C S

    2015-01-01

    In this work, we show that regular black holes in a Randall-Sundrum-type brane world model are generated by the non-local bulk influence, expressed by a constant parameter in the brane metric, only in the spherical case. In the axial case (black holes with rotation), this influence forbids them.

  3. Accretion Disks Around Black Holes: Twenty Five Years Later

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-07-10

    We study the progress of the theory of accretion disks around black holes in last twenty five years and explain why advective disks are the best bet in explaining varied stationary and non-stationary observations from black hole candidates. We show also that the recently proposed advection dominated flows are incorrect.

  4. Extracting Energy from Black Hole through Transition Region

    E-Print Network [OSTI]

    Li-Xin Li

    2000-07-24

    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.

  5. Electromagnetic Excitation of Rotating Black Holes and Relativistic Jets

    E-Print Network [OSTI]

    A. Burinskii; E. Elizalde; S. R. Hildebrandt; G. Magli

    2006-10-02

    We show that electromagnetic excitations of rotating black holes can lead to the appearance of narrow singular beams which break up the black hole horizon forming a tube-like region which connects the interior and exterior. It is argued that this effect may be at the origin of jet formation.

  6. Is the Universe the only existing Black Hole?

    E-Print Network [OSTI]

    Andrea Gregori

    2010-06-30

    We investigate the physics of black holes in the light of the quantum theoretical framework proposed in [1]. It is argued that black holes are completely non-local objects, and that the only one which really exists is the universe itself.

  7. Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors...

    Office of Environmental Management (EM)

    injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) Fuel injector Holes (Fabrication of Micro-Orifices for Fuel Injectors) 2009 DOE Hydrogen Program and Vehicle...

  8. The mechanism of the polarization dependence of the optical transmission in subwavelength metal hole arrays

    E-Print Network [OSTI]

    Zhao, Qian; Zhou, Yun-Song; Wang, Huai-Yu

    2011-01-01

    We investigate the mechanism of extraordinary optical transmission in subwave-length metal hole arrays. Experimental results for the arrays consisting of square or rectangle holes are well explained about the dependence of transmission strength on the polarization direction of the incident light. This polarization dependence occurs in each single-hole. For a hole array, there is in addition an interplay between the adjacent holes which is caused by the transverse magnetic field of surface plasmon polariton on the metal film surfaces. Based on the detailed study of a single-hole and two-hole structures, a simple method to calculate the total tranmissivity of hole arrays is proposed.

  9. Quasinormal modes of test fields around regular black holes

    E-Print Network [OSTI]

    Bobir Toshmatov; Ahmadjon Abdujabbarov; Zden?k Stuchlík; Bobomurat Ahmedov

    2015-04-25

    We study scalar, electromagnetic and gravitational test fields in the Hayward, Bardeen and Ay\\'on-Beato-Garc\\'ia regular black hole spacetimes and demonstrate that the test fields are stable in all these spacetimes. Using the sixth order WKB approximation of the linear "axial" perturbative scheme, we determine dependence of the quasinormal mode (QNM) frequencies on the characteristic parameters of the test fields and the spacetime charge parameters of the regular black holes. We give also the greybody factors, namely the transmission and reflection coefficients of scattered scalar, electromagnetic and gravitational waves. We show that damping of the QNMs in regular black hole spacetimes is suppressed in comparison to the case of Schwarzschild black holes, and increasing charge parameter of the regular black holes increases reflection and decreases transmission factor of incident waves for each of the test fields.

  10. Adaptive computation of gravitational waves from black hole interactions

    E-Print Network [OSTI]

    Philippos Papadopoulos; Edward Seidel; Lee Wild

    1998-02-27

    We construct a class of linear partial differential equations describing general perturbations of non-rotating black holes in 3D Cartesian coordinates. In contrast to the usual approach, a single equation treats all radiative $\\ell -m$ modes simultaneously, allowing the study of wave perturbations of black holes with arbitrary 3D structure, as would be present when studying the full set of nonlinear Einstein equations describing a perturbed black hole. This class of equations forms an excellent testbed to explore the computational issues of simulating black spacetimes using a three dimensional adaptive mesh refinement code. Using this code, we present results from the first fully resolved 3D solution of the equations describing perturbed black holes. We discuss both fixed and adaptive mesh refinement, refinement criteria, and the computational savings provided by adaptive techniques in 3D for such model problems of distorted black holes.

  11. Hypervelocity binary stars: smoking gun of massive binary black holes

    E-Print Network [OSTI]

    Youjun Lu; Qingjuan Yu; D. N. C. Lin

    2007-07-22

    The hypervelocity stars recently found in the Galactic halo are expelled from the Galactic center through interactions between binary stars and the central massive black hole or between single stars and a hypothetical massive binary black hole. In this paper, we demonstrate that binary stars can be ejected out of the Galactic center with velocities up to 10^3 km/s, while preserving their integrity, through interactions with a massive binary black hole. Binary stars are unlikely to attain such high velocities via scattering by a single massive black hole or through any other mechanisms. Based on the above theoretical prediction, we propose a search for binary systems among the hypervelocity stars. Discovery of hypervelocity binary stars, even one, is a definitive evidence of the existence of a massive binary black hole in the Galactic center.

  12. Weighing Black Holes in high-z SCUBA Galaxies

    E-Print Network [OSTI]

    Alexander, D M

    2006-01-01

    Deep SCUBA surveys have uncovered a population of dust-enshrouded star-forming galaxies at z~2. Using the ultra-deep 2 Ms Chandra Deep Field-North survey we recently showed that a large fraction of these systems are also undergoing intense black-hole growth. Here we provide further constraints on the properties of the black holes in SCUBA galaxies using the virial black-hole mass estimator. We show that typical SCUBA galaxies are likely to host black holes with M_BH~10^7-10^8 M_solar which are accreting at, or close to, the Eddington limit. These results provide qualitative support for our earlier conclusion that the growth of the black hole lags that of the host galaxy in these massive ultraluminous galaxies.

  13. Interface-induced heavy-hole/light-hole splitting of acceptors in silicon

    SciTech Connect (OSTI)

    Mol, J. A.; Salfi, J.; Simmons, M. Y.; Rogge, S.; Rahman, R.; Hsueh, Y.; Klimeck, G.; Miwa, J. A.

    2015-05-18

    The energy spectrum of spin-orbit coupled states of individual sub-surface boron acceptor dopants in silicon have been investigated using scanning tunneling spectroscopy at cryogenic temperatures. The spatially resolved tunnel spectra show two resonances, which we ascribe to the heavy- and light-hole Kramers doublets. This type of broken degeneracy has recently been argued to be advantageous for the lifetime of acceptor-based qubits [R. Ruskov and C. Tahan, Phys. Rev. B 88, 064308 (2013)]. The depth dependent energy splitting between the heavy- and light-hole Kramers doublets is consistent with tight binding calculations, and is in excess of 1?meV for all acceptors within the experimentally accessible depth range (<2?nm from the surface). These results will aid the development of tunable acceptor-based qubits in silicon with long coherence times and the possibility for electrical manipulation.

  14. Black hole entropy predictions without Immirzi parameter and Hawking radiation of single-partition black hole

    E-Print Network [OSTI]

    Brian Kong; Youngsub Yoon

    2015-04-14

    By pointing out an error in the previous derivation of the area spectrum based on Ashtekar's variables, we suggest a new area spectrum; in the previous derivation of the area spectrum, area operator is expressed in terms of Levi-Civita symbol instead of Levi-Civita tensor, which should have been used. At first glance, this consideration may not seem to make any difference in the actual area spectrum, but upon quantization it yields a difference, as classical equivalence doesn't always imply quantum equivalence. For this purpose, we construct our "newer" variables. In particular, our "newer" variables are mathematically consistent; the constraint algebra is closed. Moreover, by using our new area spectrum, we "almost correctly" predict the Bekenstein-Hawking entropy without adjusting Immirzi parameter; we show that a numerical formula actually turned out to be $0.997\\cdots$ which is very close to 1, the expected value with the black hole entropy given as $A/4$. We conjecture that the difference, 0.003, is due to the extra dimensions which may modify the area spectrum. Then, we derive a formula for the degeneracy for a single-partition black hole, (i.e. black hole made out of single unit area) and explicitly show that our area spectrum correctly reproduces the degeneracy. Furthermore, by two totally different methods, we obtain the proportionality constant "$C$" related to the degeneracy. The first method based on fitting yields 172$\\sim$173, while the second method yields 172.87$\\cdots$, which strongly suggest that our area spectrum is on the right track. We also show that the area spectrums based on Ashtekar variables neither reproduces the degeneracy of single-partition black hole nor yields the agreement for $C$ obtained by the two methods.

  15. Charged black holes in generalized teleparallel gravity

    SciTech Connect (OSTI)

    Rodrigues, M.E.; Houndjo, M.J.S.; Tossa, J.; Momeni, D.; Myrzakulov, R. E-mail: sthoundjo@yahoo.fr E-mail: d.momeni@yahoo.com

    2013-11-01

    In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we introduce a set of non-diagonal tetrads and derive the full system of non linear differential equations. We prove that the common Schwarzschild gauge is applicable only when we study linear f(T) case. We reobtain the Reissner-Nordstrom-de Sitter (or RN-AdS) solution for the linear case of f(T) and perform a parametric cosmological reconstruction for two nonlinear models. We also study in detail a type of the no-go theorem in the framework of this modified teleparallel gravity.

  16. Black hole thermodynamics in finite time

    E-Print Network [OSTI]

    Gruber, Christine

    2016-01-01

    Finite-time thermodynamics provides the means to revisit ideal thermodynamic equilibrium processes in the light of reality and investigate the energetic "price of haste", i.e. the consequences of carrying out a process in finite time, when perfect equilibrium cannot be awaited due to economic reasons or the nature of the process. Employing the formalism of geometric thermodynamics, a lower bound on the energy dissipated during a process is derived from the thermodynamic length of that process. The notion of length is hereby defined via a metric structure on the space of equilibrium thermodynamics, spanned by a set of thermodynamic variables describing the system. Since the aim of finite-time thermodynamics is to obtain realistic limitations on idealized scenarios, it is a useful tool to reassess the efficiency of thermodynamic processes. We examine its implications for black hole thermodynamics, in particular scenarios inspired by the Penrose process, a thought experiment by which work can be extracted from a...

  17. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Amsel, Aaron J; Virmani, Amitabh

    2008-01-01

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  18. Collisions with Black Holes and Deconfined Plasmas

    E-Print Network [OSTI]

    Aaron J. Amsel; Donald Marolf; Amitabh Virmani

    2007-12-13

    We use AdS/CFT to investigate i) high energy collisions with balls of deconfined plasma surrounded by a confining phase and ii) the rapid localized heating of a deconfined plasma. Both of these processes are dual to collisions with black holes, where they result in the nucleation of a new "arm" of the horizon reaching out in the direction of the incident object. We study the resulting non-equilibrium dynamics in a universal limit of the gravitational physics which may indicate universal behavior of deconfined plasmas at large N_c. Process (i) produces "virtual" arms of the plasma ball, while process (ii) can nucleate surprisingly large bubbles of a higher temperature phase.

  19. Thermodynamic Product Formula for Ho?ava Lifshitz Black Hole

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2015-06-10

    We examine the thermodynamic properties of inner and outer horizons in the background of Ho\\v{r}ava Lifshitz black hole. We compute the \\emph{horizon radii product, the surface area product, the entropy product, the surface temperature product, the Komar energy product and the specific heat product} for both the horizons of said black hole. We show that surface area product, entropy product and irreducible mass product are \\emph{universal} quantities, whereas the surface temperature product, Komar energy product and specific heat product are \\emph{not universal} quantities because they all are depends on mass parameter. We also observe that the \\emph{First law} of black hole thermodynamics and \\emph {Smarr-Gibbs-Duhem } relations do not hold for this black hole. The underlying reason behind this failure due to the scale invariance of the coupling constant. We further derive the \\emph{Smarr mass formula} and \\emph{Christodolou-Ruffini mass formula} for such black hole spacetime. Moreover we study the stability of such black hole by computing the specific heat for both the horizons. It has been observed that under certain condition the black hole possesses second order phase transition.

  20. Varying fine structure 'constant' and charged black holes

    SciTech Connect (OSTI)

    Bekenstein, Jacob D.; Schiffer, Marcelo

    2009-12-15

    Speculation that the fine-structure constant {alpha} varies in spacetime has a long history. We derive, in 4-D general relativity and in isotropic coordinates, the solution for a charged spherical black hole according to the framework for dynamical {alpha} J. D. Bekenstein, Phys. Rev. D 25, 1527 (1982).. This solution coincides with a previously known one-parameter extension of the dilatonic black hole family. Among the notable properties of varying-{alpha} charged black holes are adherence to a 'no hair' principle, the absence of the inner (Cauchy) horizon of the Reissner-Nordstroem black holes, the nonexistence of precisely extremal black holes, and the appearance of naked singularities in an analytic extension of the relevant metric. The exteriors of almost extremal electrically (magnetically) charged black holes have simple structures which makes their influence on applied magnetic (electric) fields transparent. We rederive the thermodynamic functions of the modified black holes; the otherwise difficult calculation of the electric potential is done by a shortcut. We confirm that variability of {alpha} in the wake of expansion of the universe does not threaten the generalized second law.

  1. Gravitational wave production by rotating primordial black holes

    E-Print Network [OSTI]

    Dong, Ruifeng; Stojkovic, Dejan

    2015-01-01

    In this paper we analyze in detail a rarely discussed question of gravity waves production from evaporating black holes. Evaporating black holes emit gravitons which are at classical level registered as gravity waves. We use the latest constraints on the primordial black hole abundance, and calculate the power emitted in gravitons at the time of their evaporation. We then solve the coupled system of equations that gives us the evolution of the frequency and amplitude of gravity waves during the expansion of the universe. The spectrum of gravitational waves that can be detected today depends on multiple factors: fraction of the total energy density which was occupied by black holes, the epoch in which the black holes are formed, and quantities like mass and angular momentum of evaporating black holes. We conclude that very small primordial black holes which evaporate before the nucleosynthesis emit gravitons whose spectral energy fraction today can be as large as $10^{-5}$. On the other hand, primordial black ...

  2. The Evolution of Accreting Black Holes in Outburst

    E-Print Network [OSTI]

    John A. Tomsick

    2004-01-12

    Black hole binaries exhibit dramatic changes in their X-ray spectral and timing properties over time, providing important clues about the physical processes that occur in these systems. Black holes and black hole candidates are prime targets for RXTE with observational goals including the study of extreme gravitational fields and jet formation mechanisms. The great wealth of data from RXTE has helped us to learn about these systems as well as raising new questions about accreting black holes. RXTE observations have allowed us to study a wide range of black hole science topics including the connection between the accretion disk and jets, the geometry of the inner accretion flow, and the physical changes that occur between spectral states. In this presentation, I discuss significant results on these topics that have been obtained for persistent and transient black holes over the past several years, and I present results from our program of X-ray and radio observations during the decays of black hole transient outbursts.

  3. Hybrid method for understanding black-hole mergers: Inspiralling case

    E-Print Network [OSTI]

    David A. Nichols; Yanbei Chen

    2012-02-21

    We adapt a method of matching post-Newtonian and black-hole-perturbation theories on a timelike surface (which proved useful for understanding head-on black-hole-binary collisions) to treat equal-mass, inspiralling black-hole binaries. We first introduce a radiation-reaction potential into this method, and we show that it leads to a self-consistent set of equations that describe the simultaneous evolution of the waveform and of the timelike matching surface. This allows us to produce a full inspiral-merger-ringdown waveform of the l=2, m=2,-2 modes of the gravitational waveform of an equal-mass black-hole-binary inspiral. These modes match those of numerical-relativity simulations well in phase, though less well in amplitude for the inspiral. As a second application of this method, we study a merger of black holes with spins antialigned in the orbital plane (the "superkick" configuration). During the ringdown of the superkick, the phases of the mass- and current-quadrupole radiation become locked together, because they evolve at the same quasinormal mode frequencies. We argue that this locking begins during merger, and we show that if the spins of the black holes evolve via geodetic precession in the perturbed black-hole spacetime of our model, then the spins precess at the orbital frequency during merger. In turn, this gives rise to the correct behavior of the radiation, and produces a kick similar to that observed in numerical simulations.

  4. Stability of black holes based on horizon thermodynamics

    E-Print Network [OSTI]

    Meng-Sen Ma; Ren Zhao

    2015-11-11

    On the basis of horizon thermodynamics we study the thermodynamic stability of black holes constructed in general relativity and Gauss-Bonnet gravity. In the framework of horizon thermodynamics there are only five thermodynamic variables $E,P,V,T,S$. It is not necessary to consider concrete matter fields, which may contribute to the pressure of black hole thermodynamic system. In non-vacuum cases, we can derive the equation of state, $P=P(V,T)$. According to the requirements of stable equilibrium in conventional thermodynamics, we start from these thermodynamic variables to calculate the heat capacity at constant pressure and Gibbs free energy and analyze the local and global thermodynamic stability of black holes. It is shown that $P>0$ is the necessary condition for black holes in general relativity to be thermodynamically stable, however this condition cannot be satisfied by many black holes in general relativity. For black hole in Gauss-Bonnet gravity negative pressure can be feasible, but only local stable black hole exists in this case.

  5. Higgs Boson Production from Black Holes at the LHC

    E-Print Network [OSTI]

    Gouranga C. Nayak; J. Smith

    2006-06-09

    If the fundamental Planck scale is near a TeV, then TeV scale black holes should be produced in proton-proton collisions at the LHC where \\sqrt{s} = 14 TeV. As the temperature of the black holes can be ~ 1 TeV we also expect production of Higgs bosons from them via Hawking radiation. This is a different production mode for the Higgs boson, which would normally be produced via direct pQCD parton fusion processes. In this paper we compare total cross sections and transverse momentum distributions d\\sigma/dp_T for Higgs production from black holes at the LHC with those from direct parton fusion processes at next-to-next-to-leading order and next-to-leading order respectively. We find that the Higgs production from black holes can be larger or smaller than the direct pQCD production depending upon the Planck mass and black hole mass. We also find that d\\sigma/dp_T of Higgs production from black holes increases as a function of p_T which is in sharp contrast with the pQCD predictions where d\\sigma/dp_T decreases so we suggest that the measurement of an increase in d\\sigma/dp_T as p_T increases for Higgs (or any other heavy particle) production can be a useful signature for black holes at the LHC.

  6. SLIM: A Scalable Location-Sensitive Information Monitoring Service

    E-Print Network [OSTI]

    Liu, Ling

    . A typical example of such services is "alert me when the gas price at a gas station within 5 miles of my current location drops to $4 per gallon". Such a service needs to monitor the gas price changes gas prices at gas stations, traffic conditions at major junctions or pollution levels in different

  7. High Precision Geophysics & Detailed Structural Exploration & Slim Well

    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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QAsource History View NewTexas: Energy Resources Jump to:Hershey, Pennsylvania:Hidden

  8. Slim Lake, Minnesota: Energy Resources | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing Capacity forSilicium de ProvenceSolar Jump

  9. Black Hole Thermodynamic Products in Einstein Gauss Bonnet Gravity

    E-Print Network [OSTI]

    Mandal, Abhijit

    2015-01-01

    We study the thermodynamic properties of black hole horizons in Einstein Gauss Bonnet gravity. We derive the thermodynamic products of characteristic parameters to mark which are global. We further interpret the stability of the black holes by computing the specific heat for both horizons. Stable and unstable phases of horizons are pointed out. The phase transitions with respect to the charge in nature of specific heat are also observed. All these calculation might be helpful to understand the microscopic nature of such black holes.

  10. Inferring black hole charge from backscattered electromagnetic radiation

    E-Print Network [OSTI]

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

    2014-09-16

    We compute the scattering cross section of Reissner-Nordstr\\"om black holes for the case of an incident electromagnetic wave. We describe how scattering is affected by both the conversion of electromagnetic to gravitational radiation, and the parity-dependence of phase shifts induced by the black hole charge. The latter effect creates a helicity-reversed scattering amplitude that is non-zero in the backward direction. We show that from the character of the electromagnetic wave scattered in the backward direction it is possible, in principle, to infer if a static black hole is charged.

  11. Back reaction on a Reissner-Nordstro''m black hole

    SciTech Connect (OSTI)

    Wang, Bobo; Huang, Chao-guang

    2001-06-15

    The perturbed (''dressed'') metric of the conformally invariant scalar field in a Reissner-Nordstroem (RN) black hole is given by solving the semiclassical Einstein and Maxwell equations according to York's back-reaction approach. Some properties of the ''dressed'' black hole are obtained, such as its ''dressed'' mass, the location of the event horizon, and its surface gravity. It will also be found that the hypersurfaces of r{sub +} and r{sub {minus}} which are the event and Cauchy horizons in the ''naked'' RN black hole, become spacelike in the perturbed geometry.

  12. A Nonsingular Brans Wormhole: An Analogue to Naked Black Holes

    E-Print Network [OSTI]

    Amrita Bhattacharya; Ramil Izmailov; Ettore Laserra; Kamal K. Nandi

    2011-07-28

    In a recent paper, we showed the Jordan frame vacuum Brans Class I solution provided a wormhole analogue to Horowitz-Ross naked black hole in the wormhole range -3/2naked black holes, as described by Horowitz and Ross, are spacetimes where the tidal forces attain their maxima above the black hole horizon. We show that in the non-singular Class II spacetime this maxima is attained above the throat and thus can be treated as a wormhole analogue. Some related issues are also addressed.

  13. From Special Geometry to Black Hole Partition Functions

    E-Print Network [OSTI]

    Thomas Mohaupt

    2008-12-22

    These notes are based on lectures given at the Erwin-Schrodinger Insitut in Vienna in 2006/07 and at the 2007 School on Attractor Mechanism in Frascati. Lecture I: special geometry from the superconformal point of view. Lecture II: black hole attractor mechanism, its underlying variational principle, and black hole partition functions. Lecture III: large and small BPS black holes in N=4 supergravity. Lecture IV: state counting for N=4 string compactifications. Appendix A: special geometry from the mathematical point of view. Appendix B: review of modular forms. Contains four problems which allow the readers to develop some of the key concepts by themselves.

  14. Hole Localization in Molecular Crystals from Hybrid Density Functional Theory

    SciTech Connect (OSTI)

    Sai, Na; Barbara, Paul F.; Leung, Kevin

    2011-06-02

    We use first-principles computational methods to examine hole trapping in organic molecular crystals. We present a computational scheme based on the tuning of the fraction of exact exchange in hybrid density functional theory to eliminate the many-electron self-interaction error. With small organic molecules, we show that this scheme gives accurate descriptions of ionization and dimer dissociation. We demonstrate that the excess hole in perfect molecular crystals forms self-trapped molecular polarons. The predicted absolute ionization potentials of both localized and delocalized holes are consistent with experimental values.

  15. Static Charged Black Hole Solutions in Horava-Lifshitz Gravity

    E-Print Network [OSTI]

    Jin-Zhang Tang

    2010-01-12

    In the present work, we search static charged black hole solutions to Ho\\v{r}ava-Lifshitz gravity with or without projectability condition. We consider the most general form of action which electromagnetic field couples with Ho\\v{r}ava-Lifshitz gravity. With the projectability condition, we find dS-Reissner-Nordstrom black hole solution in Painlev\\'e-Gullstrand type coordinates in the IR region and a de-Sitter space-time solution in the UV region. Without the projectability condition, in the IR region, we find an especial static charged black hole solution.

  16. The r-Process in Black Hole Winds

    E-Print Network [OSTI]

    Shinya Wanajo; Hans-Thomas Janka

    2010-06-11

    All the current r-process scenarios relevant to core-collapse supernovae are facing severe difficulties. In particular, recent core-collapse simulations with neutrino transport show no sign of a neutron-rich wind from the proto-neutron star. In this paper, we discuss nucleosynthesis of the r-process in an alternative astrophysical site, "black hole winds", which are the neutrino-driven outflow from the accretion torus around a black hole. This condition is assumed to be realized in double neutron star mergers, neutron star - black hole mergers, or hypernovae.

  17. Scalar emission in a rotating Gödel black hole

    E-Print Network [OSTI]

    Songbai Chen; Bin Wang; Jiliang Jing

    2008-08-23

    We study the absorption probability and Hawking radiation of the scalar field in the rotating G\\"{o}del black hole in minimal five-dimensional gauged supergravity. We find that G\\"{o}del parameter $j$ imprints in the greybody factor and Hawking radiation. It plays a different role from the angular momentum of the black hole in the Hawking radiation and super-radiance. These information can help us know more about rotating G\\"{o}del black holes in minimal five-dimensional gauged supergravity.

  18. Little Black Holes:Dark Matter And Ball Lightning

    E-Print Network [OSTI]

    Mario Rabinowitz

    2002-12-11

    Small,quiescent black holes can be considered as candidates for the missing dark matter of the universe,and as the core energy source of ball lightning.By means of gravitational tunneling,directed radiation is emitted from black holes in a process much attenuated from that of Hawking radiation,P SH, which has proven elusive to detect.Gravitational tunneling emission is similar to electric field emission of electronsfrom a metal in that a second body is involved which lowers the barrier and gives the barrier a finite rather than infinite width.Hawking deals with a single isolated black hole.

  19. Recent Progresses Of Accretion Disk Models Around Black Holes

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1997-03-09

    Accretion disk models have evolved from Bondi flows in the 1950s to Keplerian disks in the 1970s and finally to advective transonic flows in the 1990s. We discuss recent progresses in this subject and show that sub-Keplerian flows play a major role in determining the spectral properties of black holes. Centrifugal pressure supported enhanced density region outside the black hole horizon produces hard X-rays and gamma rays by reprocessing intercepted soft photons emitted by the Keplerian disk terminated farther out from the black holes. Quasi-periodic oscillations can also be understood from the dynamic or thermal resonance effects of the enhanced density region.

  20. Neutron Hole States of Mo-93,95 

    E-Print Network [OSTI]

    Bindal, P. K.; Youngblood, David H.; Kozub, R. L.

    1977-01-01

    ?; calculated ~, &, S?, quasi- particle-core coupling model. I. INTRODUCTION This paper concludes a series of nuclear struc- ture studies of proton particle' and hole' states and neutron hole states'4 of odd-A nuclei in the A =90-100 region. The study... by Moinester et ul. ,' as their resolution was -100 keV. Finally, the re- sults are compared with the predictions of a guasi- particle-core coupling model which has been ap- plied by us in our previous studies of neutron and proton hole states...

  1. MEMS Materials and Temperature Sensors for Down Hole Geothermal System Monitoring

    E-Print Network [OSTI]

    Wodin-Schwartz, Sarah

    2013-01-01

    Monitoring Geothermal Environments . . . . . . . . . . . . . . . . . . . . . . . . . . . .down hole environment monitoring. Harsh environment sensorsfor Geothermal Monitoring Harsh environment MEMS sensors

  2. Extraordinary transmission through 1, 2 and 3 holes in a perfect conductor,

    E-Print Network [OSTI]

    hole, caused by the Fabry-Perot effect inside the hole. Furthermore, we study the fundamental building block for extraordinary transmission through hole arrays: two and three holes. Coupled electromagnetic.1220) Apertures; (050.1960) Diffraction theory. References and links 1. H.A. Bethe, "Theory of diffraction

  3. Rotordynamic evaluation of frequency dependent impedances of hole-pattern gas damper seals 

    E-Print Network [OSTI]

    Holt, Christopher George

    2000-01-01

    Two hole-pattern seals are compared with one smooth bore seal. The two hole-pattern seals have cell depths of 2.03 mm and 3.18 mm with a cell diameter of 1.59 mm. The hole area density factor for both hole-pattern seals is 43%. The L/D ratio...

  4. Giant black hole ringings induced by massive gravity

    E-Print Network [OSTI]

    Yves Decanini; Antoine Folacci; Mohamed Ould El Hadj

    2014-01-01

    A distorted black hole radiates gravitational waves in order to settle down in one of the geometries permitted by the no-hair theorem. During that relaxation phase, a characteristic damped ringing is generated. It can be theoretically constructed from the black hole quasinormal frequencies (which govern its oscillating behavior and its decay) and from the associated excitation factors (which determine intrinsically its amplitude) by carefully taking into account the source of the distortion. Here, by considering the Schwarzschild black hole in the framework of massive gravity, we show that the excitation factors have an unexpected strong resonant behavior leading to giant ringings which are, moreover, slowly decaying. Such extraordinary black hole ringings could be observed by the next generations of gravitational wave detectors and allow us to test the various massive gravity theories or their absence could be used to impose strong constraints on the graviton mass.

  5. Black Holes in Gauss-Bonnet Gravity's Rainbow

    E-Print Network [OSTI]

    Seyed Hossein Hendi; Mir Faizal

    2015-08-08

    In this paper, we will generalize the Gauss-Bonnet gravity to an energy dependent Gauss-Bonnet theory of gravity, which we shall call as the Gauss-Bonnet gravity's rainbow. We will also couple this theory to a Maxwell's theory. We will analyze black hole solutions in this energy dependent Gauss-Bonnet gravity's rainbow. We will calculate the modifications to the thermodynamics of black holes in the Gauss-Bonnet's gravity's rainbow. We will demonstrate that even though the thermodynamics of the black holes get modified in the Gauss-Bonnet gravity's rainbow, the first law of thermodynamics still holds for this modified thermodynamics. We will also comment on the thermal stability of the black hole solutions in this theory.

  6. Temperatures, heat flow, and water chemistry from drill holes...

    Open Energy Info (EERE)

    Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...

  7. Black hole physics: recent developments and observational perspectives

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release: a very deep gravitational potential well Release of potential gravitational energy by accretion

  8. Black holes and tests of gravitation Eric Gourgoulhon

    E-Print Network [OSTI]

    Gourgoulhon, Eric

    potential well Release of potential gravitational energy by accretion on a black hole: up to 42% of the mass-energy mc2 of accreted matter ! NB: thermonuclear reactions release less than 1% mc2 Matter falling

  9. Black hole evaporation in a noncommutative charged Vaidya model

    SciTech Connect (OSTI)

    Sharif, M. Javed, W.

    2012-06-15

    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.

  10. Core Lithology State of Hawail Scientific Observation Hole 2...

    Open Energy Info (EERE)

    Core Lithology State of Hawail Scientific Observation Hole 2 Kilauea Volcano, Hawaii Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Core Lithology State...

  11. Core Lithology State of Hawaii Scientific Observation Hole 4...

    Open Energy Info (EERE)

    Core Lithology State of Hawaii Scientific Observation Hole 4 Kilauea Volcano, Hawaii Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Core Lithology State...

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

    Open Energy Info (EERE)

    Evaluation of Coso Geothermal Exploratory Hole No. 1 (CGEH-1) Coso Hot Springs: KGRA, China Lake, CA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...

  13. Microthermometry of Fluid Inclusions from the VC-1 Core Hole...

    Open Energy Info (EERE)

    Caldera, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Microthermometry of Fluid Inclusions from the VC-1 Core Hole in Valles...

  14. Tensile Strength and the Mining of Black Holes

    E-Print Network [OSTI]

    Adam R. Brown

    2012-07-13

    There are a number of important thought experiments that involve raising and lowering boxes full of radiation in the vicinity of black hole horizons. This paper looks at the limitations placed on these thought experiments by the null energy condition, which imposes a fundamental bound on the tensile-strength-to-weight ratio of the materials involved, makes it impossible to build a box near the horizon that is wider than a single wavelength of the Hawking quanta and puts a severe constraint on the operation of 'space elevators' near black holes. In particular, it is shown that proposals for mining black holes by lowering boxes near the horizon, collecting some Hawking radiation and dragging it out to infinity cannot proceed nearly as rapidly as has previously been claimed and that as a consequence of this limitation the boxes and all the moving parts are superfluous and black holes can be destroyed equally rapidly by threading the horizon with strings.

  15. Circumnuclear Media and Accretion Rates of Quiescent Supermassive Black Holes

    E-Print Network [OSTI]

    Generozov, Aleksey; Metzger, Brian D

    2015-01-01

    We calculate steady-state, one-dimensional hydrodynamic profiles of hot gas in slowly accreting ("quiescent") galactic nuclei for a range of central black hole masses, parameterized gas heating rates, and observationally-motivated stellar density profiles. Mass is supplied to the circumnuclear medium by stellar winds, while energy is injected primarily by stellar winds, supernovae, and black hole feedback. Analytic estimates are derived for the stagnation radius (where the radial velocity of the gas passes through zero) and the black hole accretion rate, as a function of the black hole mass and the gas heating efficiency, the latter being related to the star-formation history. We assess the conditions under which radiative instabilities develop in the hydrostatic region near the stagnation radius, both in the case of a single burst of star formation and for the average star formation history predicted by cosmological simulations. By combining a sample of measured nuclear X-ray luminosities from nearby quiesce...

  16. Could there be a hole in type Ia supernovae?

    E-Print Network [OSTI]

    Kasen, Daniel; Nugent, Peter; Thomas, R.C.; Wang, Lifan

    2004-01-01

    Highlight: The Physics of Supernovae. Pro- ceedings of the EThere Be A Hole In Type l a Supernovae? Daniel Kasen, Peterscenario, Type l a Supernovae (SNe la) arise from a white

  17. Improvements to the construction of binary black hole initial data

    E-Print Network [OSTI]

    Serguei Ossokine; Francois Foucart; Harald P. Pfeiffer; Michael Boyle; Béla Szilágyi

    2015-06-04

    Construction of binary black hole initial data is a prerequisite for numerical evolutions of binary black holes. This paper reports improvements to the binary black hole initial data solver in the Spectral Einstein Code, to allow robust construction of initial data for mass-ratio above 10:1, and for dimensionless black hole spins above 0.9, while improving efficiency for lower mass-ratios and spins. We implement a more flexible domain decomposition, adaptive mesh refinement and an updated method for choosing free parameters. We also introduce a new method to control and eliminate residual linear momentum in initial data for precessing systems, and demonstrate that it eliminates gravitational mode mixing during the evolution. Finally, the new code is applied to construct initial data for hyperbolic scattering and for binaries with very small separation.

  18. The Energy for 2+1 Dimensional Black Hole Solutions

    E-Print Network [OSTI]

    I-Ching Yang; Irina Radinschi

    2006-11-05

    The energy distributions of four 2+1 dimensional black hole solutions were obtained by using the Einstein and M{\\o}ller energy-momentum complexes. while $r \\to \\infty$, the energy distributions of these four solutions become divergence.

  19. Quantum Emission from Two-Dimensional Black Holes

    E-Print Network [OSTI]

    Steven B. Giddings; W. M. Nelson

    2009-11-27

    We investigate Hawking radiation from two-dimensional dilatonic black holes using standard quantization techniques. In the background of a collapsing black hole solution the Bogoliubov coefficients can be exactly determined. In the regime after the black hole has settled down to an `equilibrium' state but before the backreaction becomes important these give the known result of a thermal distribution of Hawking radiation at temperature lambda/(2pi). The density matrix is computed in this regime and shown to be purely thermal. Similar techniques can be used to derive the stress tensor. The resulting expression agrees with the derivation based on the conformal anomaly and can be used to incorporate the backreaction. Corrections to the thermal density matrix are also examined, and it is argued that to leading order in perturbation theory the effect of the backreaction is to modify the Bogoliubov transformation, but not in a way that restores information lost to the black holes.

  20. Core Holes At Valles Caldera - Sulphur Springs Geothermal Area...

    Open Energy Info (EERE)

    Dennis L. Nielson, Pisto Larry, C.W. Criswell, R. Gribble, K. Meeker, J.A. Musgrave, T. Smith, D. Wilson (1989) Scientific Core Hole Valles Caldera No. 2B (VC-2B), New Mexico:...

  1. An Energy Extremum Principle for Charged Black Holes

    E-Print Network [OSTI]

    Fraser, Scott

    2015-01-01

    For a set of asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well-separated, we prove the following extremum principle: the extremal charge configuration ($|q_i|=m_i$ for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for static black holes, and is consistent with the independently known BPS energy minimum.

  2. An Energy Extremum Principle for Charged Black Holes

    E-Print Network [OSTI]

    Scott Fraser; Shaker Von Price Funkhouser

    2015-09-13

    For a set of asymptotically flat black holes with arbitrary charges and masses, all initially at rest and well-separated, we prove the following extremum principle: the extremal charge configuration ($|q_i|=m_i$ for each black hole) can be derived by extremizing the total energy, for variations of the black hole apparent horizon areas, at fixed charges and fixed Euclidean separations. If all charges have the same sign, this result is a variational principle that reinterprets the static equilibrium of the Majumdar-Papapetrou-Hartle-Hawking solution as an extremum of total energy, rather than as a balance of forces; this result augments a list of related variational principles for static black holes, and is consistent with the independently known BPS energy minimum.

  3. Energy Distribution of a Stringy Charged Black Hole

    E-Print Network [OSTI]

    Ragab M. Gad

    2003-06-22

    The energy distribution associated with a stringy charged black hole is studied using M{\\o}ller's energy-momentum complex. Our result is reasonable and it differs from that known in literature using Einstein's energy-momentum complex.

  4. Black hole remnant in asymptotic Anti-de Sitter space

    E-Print Network [OSTI]

    Wen, Wen-Yu

    2015-01-01

    It is known that a solution of remnant were suggested for black hole ground state after surface gravity is corrected by loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic Anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking-Page phase transition. In this letter, we investigate the low temperature phase of three-dimensional BTZ black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored than the remnant solution at low temperature in three dimensions, while Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to be found in the overcooled phase if strings were present and its implication is discussed.

  5. Spectral Properties of Galactic and Extragalactic Black Hole Candidates

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    We review current theoretical understanding of the spectral properties (low and high states, transition of states, quasi-periodic oscillations etc.) of the low mass as well as supermassive black hole candidates.

  6. Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide...

    Office of Scientific and Technical Information (OSTI)

    Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143JPSJ.81.054704 Citation Details In-Document...

  7. FOR THE RECORD RosettaHoles2: A volumetric packing

    E-Print Network [OSTI]

    Baker, David

    FOR THE RECORD RosettaHoles2: A volumetric packing measure for protein structure refinement volumetric in nature. However, the total cavity volume is not a good dis- criminator between computational

  8. Black Hole Demographics from the M(BH)-sigma Relation

    E-Print Network [OSTI]

    David Merritt; Laura Ferrarese

    2001-03-03

    We analyze a sample of 32 galaxies for which a dynamical estimate of the mass of the hot stellar component, M_bulge, is available. For each of these galaxies, we calculate the mass of the central black hole, M_BH, using the tight empirical correlation between M_BH and the bulge stellar velocity dispersion. The frequency function N(log M_BH/M_bulge) is reasonably well described as a Gaussian with ~ -2.90 and standard deviation 0.45; the implied mean ratio of black hole to bulge mass is a factor 5 smaller than generally quoted in the literature. We present marginal evidence for a lower, average black-hole mass fraction in more massive galaxies. The total mass density in black holes in the local Universe is estimated to be 5 x 10^5 solar masses per cubic megaparsec, consistent with that inferred from high redshift (z ~ 2) AGNs.

  9. Electromagnetic quasinormal modes of D-dimensional black holes

    E-Print Network [OSTI]

    A. López-Ortega

    2006-11-02

    Using the monodromy method we calculate the asymptotic quasinormal (QN) frequencies of an electromagnetic field moving in D-dimensional Schwarzschild and Schwarzschild de Sitter (SdS) black holes ($D\\geq 4$). For the D-dimensional Schwarzschild anti-de Sitter (SadS) black hole we also compute these frequencies with a similar method. Moreover, we calculate the electromagnetic normal modes of the D-dimensional anti-de Sitter (AdS) spacetime.

  10. Linear waves in the interior of extremal black holes I

    E-Print Network [OSTI]

    Gajic, Dejan

    2015-01-01

    We consider solutions to the linear wave equation in the interior region of extremal Reissner-Nordstr\\"om black holes. We show that, under suitable assumptions on the initial data, the solutions can be extended continuously beyond the Cauchy horizon and moreover, that their local energy is finite. This result is in contrast with previously established results for subextremal Reissner-Nordstr\\"om black holes, where the local energy was shown to generically blow up at the Cauchy horizon.

  11. Black Hole Statistical Mechanics and The Angular Velocity Ensemble

    E-Print Network [OSTI]

    Mitchell Thomson; Charles C. Dyer

    2012-03-29

    An new ensemble - the angular velocity ensemble - is derived using Jaynes' method of maximising entropy subject to prior information constraints. The relevance of the ensemble to black holes is motivated by a discussion of external parameters in statistical mechanics and their absence from the Hamiltonian of general relativity. It is shown how this leads to difficulty in deriving entropy as a function of state and recovering the first law of thermodynamics from the microcanonical and canonical ensembles applied to black holes.

  12. Spectral Properties of Black Holes in Gamma Rays

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    2005-01-14

    Black holes are the most compact objects in the universe. Therefore, matter accreting onto is likely to radiate photons of energy comparable to very high gravitational potential energy. We discuss the nature of the emitted radiation in X-rays and gamma-rays from black hole candidates. We present theoretical solutions which comprise both Keplerian and sub-Keplerian components and suggest that shocks in accretion and outflows

  13. Bounding the greybody factors for Schwarzschild black holes

    E-Print Network [OSTI]

    Boonserm, Petarpa

    2008-01-01

    Greybody factors in black hole physics modify the naive Planckian spectrum that is predicted for Hawking radiation when working in the limit of geometrical optics. We consider the Schwarzschild geometry in (3+1) dimensions, and analyze the Regge-Wheeler equation for arbitrary particle spin S and wave-mode angular momentum L, deriving rigourous bounds on the greybody factors as a function of S, L, wave frequency (omega), and the black hole mass, m.

  14. Masses of Stellar Black Holes and Testing Theories of Gravitation

    E-Print Network [OSTI]

    K. A. Postnov; A. M. Cherepashchuk

    2004-01-22

    We analyze the mass distribution of stellar black holes derived from the light and radial velocity curves of optical stars in close binary systems using dynamical methods. The systematic errors inherent in this approach are discussed. These are associated primarily with uncertainties in models for the contribution from gaseous structures to the optical brightness of the systems under consideration. The mass distribution is nearly flat in the range 4-15M_sun. This is compared with the mass distribution for black holes in massive close binaries, which can be manifest as ultraluminous X-ray sources (L_x > 10^39 erg/s) observed in other galaxies. If the X-ray luminosities of these objects correspond to the Eddington limit, the black-hole mass distribution should be described by a power law, which is incompatible with the flat shape derived dynamically from observations of close binaries in our Galaxy. One possible explanation of this discrepancy is the rapid evaporation of stellar-mass black holes predicted in recent multi-dimensional models of gravity. This hypothesis can be verifed by measuring the stellar black-hole mass spectrum or finding isolated or binary black holes with masses below 3M_sun.

  15. Energy spectrum of black holes : a new view

    E-Print Network [OSTI]

    Abhishek Majhi

    2015-12-22

    Energy of a black hole is usually quantized by invoking some area quantization scheme after expressing the energy in terms of the horizon area. However, in this approach one has to quantize the local and asymptotic energy of the black hole separately and the two results do not manifest any physical correspondence with each other. Here, as opposed to this practice, we find the unique energy spectrum of black holes by adopting a top-down approach. The physical links among the underlying quantum theory, statistical mechanics and thermodynamics of the black hole horizon play the central role in determining the energy spectrum. The energy spectrum that we obtain, explicitly reveals the correspondence between asymptotic and local observations through the presence of the surface gravity of the horizon as a parameter in the spectrum, rather than being expressed as a function of area and consequently getting quantized in the usual approach. Thus, our result presents a new view as far as black hole energy quantization is concerned. The calculations are performed using the quantum geometric description of black hole horizons as laid down by loop quantum gravity.

  16. Spin alignment and differential accretion in merging black hole binaries

    E-Print Network [OSTI]

    Davide Gerosa; Benedetta Veronesi; Giuseppe Lodato; Giovanni Rosotti

    2015-07-01

    Interactions between a supermassive black hole binary and the surrounding accretion disc can both assist the binary inspiral and align the black hole spins to the disc angular momentum. While binary migration is due to angular-momentum transfer within the circumbinary disc, the spin-alignment process is driven by the mass accreting on to each black hole. Mass transfer between different disc components thus couples the inspiral and the alignment process together. Mass is expected to leak through the cavity cleared by the binary, and preferentially accretes on to the lighter (secondary) black hole which orbits closer to the disc edge. Low accretion rate on to the heavier (primary) black hole slows the alignment process down. We revisit the problem and develop a semi-analytical model to describe the coupling between gas-driven inspiral and spin alignment, finding that binaries with mass ratio qprimaries from aligning. Binary black holes with misaligned primaries are ideal candidates for precession effects in the strong-gravity regime and may suffer from moderately large (~1500 km/s) recoil velocities.

  17. Relating Follicly-Challenged Compact Stars to Bald Black Holes

    E-Print Network [OSTI]

    Kent Yagi; Nicolas Yunes

    2015-07-08

    Compact stars satisfy certain no-hair relations through which their multipole moments are given by their mass, spin and quadrupole moment. These relations are approximately independent of their equation of state, relating pressure to density. Such relations are similar to the black hole no-hair theorems, but these possess event horizons inside which information that led to their formation can hide. Compact stars do not possess horizons, so whether their no-hair relations are related to the black hole ones is unclear. We investigate how the two relations are related by studying relations among multipole moments for compact stars with anisotropic pressure as a toy model, which allows such stars to be more compact than those with isotropic pressure. We here show numerically that the compact star no-hair relations approach the black hole ones as the compactness approaches that of a black hole. We also prove analytically that the current dipole moment exactly reaches the black hole limit quadratically in compactness as strongly-anisotropic stars approach the black hole limit. We moreover show that compact stars become progressively oblate in this limit, even if prolate at low compactness due to strong anisotropies.

  18. Dipole radiation from a cylindrical hole in the earth.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Johnson, William Arthur; Basilio, Lorena I.

    2005-08-01

    This report examines the problem of an antenna radiating from a cylindrical hole in the earth and the subsequent far-zone field produced in the upper air half space. The approach used for this analysis was to first examine propagation characteristics along the hole for surrounding geologic material properties. Three cases of sand with various levels of moisture content were considered as the surrounding material to the hole. For the hole diameters and sand cases examined, the radiation through the earth medium was found to be the dominant contribution to the radiation transmitted through to the upper half-space. In the analysis presented, the radiation from a vertical and a horizontal dipole source within the hole is used to determine a closed-form expression for the radiation in the earth medium which represents a modified element factor for the source and hole combination. As the final step, the well-known results for a dipole below a half space, in conjunction with the use of Snell's law to transform the modified element factor to the upper half space, determine closed-form expressions for the far-zone radiated fields in the air region above the earth.

  19. Could there be a hole in type Ia supernovae?

    SciTech Connect (OSTI)

    Kasen, Daniel; Nugent, Peter; Thomas, R.C.; Wang, Lifan

    2004-04-23

    In the favored progenitor scenario, Type Ia supernovae (SNe Ia) arise from a white dwarf accreting material from a non-degenerate companion star. Soon after the white dwarf explodes, the ejected supernova material engulfs the companion star; two-dimensional hydrodynamical simulations by Marietta et al. (2001) show that, in the interaction, the companion star carves out a conical hole of opening angle 30-40 degrees in the supernova ejecta. In this paper we use multi-dimensional Monte Carlo radiative transfer calculations to explore the observable consequences of an ejecta-hole asymmetry. We calculate the variation of the spectrum, luminosity, and polarization with viewing angle for the aspherical supernova near maximum light. We find that the supernova looks normal from almost all viewing angles except when one looks almost directly down the hole. In the latter case, one sees into the deeper, hotter layers of ejecta. The supernova is relatively brighter and has a peculiar spectrum characterized by more highly ionized species, weaker absorption features, and lower absorption velocities. The spectrum viewed down the hole is comparable to the class of SN 1991T-like supernovae. We consider how the ejecta-hole asymmetry may explain the current spectropolarimetric observations of SNe Ia, and suggest a few observational signatures of the geometry. Finally, we discuss the variety currently seen in observed SNe Ia and how an ejecta-hole asymmetry may fit in as one of several possible sources of diversity.

  20. Nonlinearly charged Lifshitz black holes for any exponent $z>1$

    E-Print Network [OSTI]

    Abigail Alvarez; Eloy Ayón-Beato; Hernán A. González; Mokhtar Hassaïne

    2015-01-27

    Charged Lifshitz black holes for the Einstein-Proca-Maxwell system with a negative cosmological constant in arbitrary dimension $D$ are known only if the dynamical critical exponent is fixed as $z=2(D-2)$. In the present work, we show that these configurations can be extended to much more general charged black holes which in addition exist for any value of the dynamical exponent $z>1$ by considering a nonlinear electrodynamics instead of the Maxwell theory. More precisely, we introduce a two-parametric nonlinear electrodynamics defined in the more general, but less known, so-called $(\\mathcal{H},P)$-formalism and obtain a family of charged black hole solutions depending on two parameters. We also remark that the value of the dynamical exponent $z=D-2$ turns out to be critical in the sense that it yields asymptotically Lifshitz black holes with logarithmic decay supported by a particular logarithmic electrodynamics. All these configurations include extremal Lifshitz black holes. Charged topological Lifshitz black holes are also shown to emerge by slightly generalizing the proposed electrodynamics.

  1. Stability of black holes based on horizon thermodynamics

    E-Print Network [OSTI]

    Ma, Meng-Sen

    2015-01-01

    On the basis of horizon thermodynamics we study the thermodynamic stability of black holes constructed in general relativity and Gauss-Bonnet gravity. In the framework of horizon thermodynamics there are only five thermodynamic variables $E,P,V,T,S$. It is not necessary to consider concrete matter fields, which may contribute to the pressure of black hole thermodynamic system. In non-vacuum cases, we can derive the equation of state, $P=P(V,T)$. According to the requirements of stable equilibrium in conventional thermodynamics, we start from these thermodynamic variables to calculate the heat capacity at constant pressure and Gibbs free energy and analyze the local and global thermodynamic stability of black holes. It is shown that $P>0$ is the necessary condition for black holes in general relativity to be thermodynamically stable, however this condition cannot be satisfied by many black holes in general relativity. For black hole in Gauss-Bonnet gravity negative pressure can be feasible, but only local stab...

  2. Bright vigorous winds as signposts of supermassive black hole birth

    E-Print Network [OSTI]

    Fiacconi, Davide

    2015-01-01

    The formation of supermassive black holes is still an outstanding question. In the quasi-star scenario, black hole seeds experience an initial super-Eddington growth, that in less than a million years may leave a $10^4-10^5$ M$_{\\odot}$ black hole at the centre of a protogalaxy at $z \\sim 20-10$. Super-Eddington accretion, however, may be accompanied by vigorous mass loss that can limit the amount of mass that reaches the black hole. In this paper, we critically assess the impact of radiative driven winds, launched from the surface of the massive envelopes from which the black hole accretes. Solving the full wind equations coupled with the hydrostatic structure of the envelope, we find mass outflows with rates between a few tens and $10^4$ M$_{\\odot}$ yr$^{-1}$, mainly powered by advection luminosity within the outflow. We therefore confirm the claim by Dotan, Rossi & Shaviv (2011) that mass losses can severely affect the black hole seed early growth within a quasi-star. In particular, seeds with mass $>1...

  3. Dissipative accretion flows around a rotating black hole

    E-Print Network [OSTI]

    Santabrata Das; Sandip K. Chakrabarti

    2008-06-12

    We study the dynamical structure of a cooling dominated rotating accretion flow around a spinning black hole. We show that non-linear phenomena such as shock waves can be studied in terms of only three flow parameters, namely, the specific energy (${\\cal E}$), the specific angular momentum ($\\lambda$) and the accretion rate (${\\dot m}$) of the flow. We present all possible accretion solutions. We find that a significant region of the parameter space in the ${\\cal E}-\\lambda$ plane allows global accretion shock solutions. The effective area of the parameter space for which the Rankine-Hugoniot shocks are possible is maximum when the flow is dissipation free. It decreases with the increase of cooling effects and finally disappears when the cooling is high enough. We show that shock forms further away when the black hole is rotating compared to the solution around a Schwarzschild black hole with identical flow parameters at a large distance. However, in a normalized sense, the flow parameters for which the shocks form around the rotating black holes are produced shocks closer to the hole. The location of the shock is also dictated by the cooling efficiency in that higher the accretion rate (${\\dot m}$), the closer is the shock location. We believe that some of the high frequency quasi-periodic oscillations may be due to the flows with higher accretion rate around the rotating black holes.

  4. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Giuseppe Lodato; Priyamvada Natarajan

    2007-02-13

    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.

  5. Black holes in young stellar clusters

    SciTech Connect (OSTI)

    Goswami, Sanghamitra; Kiel, Paul; Rasio, Frederic A. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States)

    2014-02-01

    We present theoretical models for stellar black hole (BH) properties in young, massive star clusters. Using a Monte Carlo code for stellar dynamics, we model realistic star clusters with N ? 5 × 10{sup 5} stars and significant binary fractions (up to 50%) with self-consistent treatments of stellar dynamics and stellar evolution. We compute the formation rates and characteristic properties of single and binary BHs for various representative ages, cluster parameters, and metallicities. Because of dynamical interactions and supernova (SN) kicks, more single BHs end up retained in clusters compared to BHs in binaries. We also find that the ejection of BHs from a cluster is a strong function of initial density. In low-density clusters (where dynamical effects are negligible), it is mainly SN kicks that eject BHs from the cluster, whereas in high-density clusters (initial central density ? {sub c}(0) ? 10{sup 5} M {sub ?} pc{sup –3} in our models) the BH ejection rate is enhanced significantly by dynamics. Dynamical interactions of binary systems in dense clusters also modify the orbital period and eccentricity distributions while increasing the probability of a BH having a more massive companion.

  6. Black Hole Spectral States and Physical Connections

    E-Print Network [OSTI]

    John A. Tomsick

    2005-09-06

    The dramatic changes seen in the X-ray spectral and timing properties of accreting black hole candidates (BHCs) provide important clues about the accretion and jet formation processes that occur in these systems. Dividing the different source behaviors into spectral states provides a framework for studying BHCs. To date, there have been three main classification schemes with Luminosity-based, Component-based, or Transition-based criteria. The canonical, Luminosity-based criteria and physical models that are based on this concept do not provide clear explanations for several phenomena, including hysteresis of spectral states and the presence of jets. I discuss the re-definitions of states, focusing on an application of the Component-based states to more than 400 RXTE observations of the recurrent BHC 4U 1630-47. We compare the X-ray properties for the recent 2002-2004 outburst to those of an earlier (1998) outburst, during which radio jets were observed. The results suggest a connection between hysteresis of states and major jet ejections, and it is possible that both of these are related to the evolution of the inner radius of the optically thick accretion disk.

  7. Bubbling supertubes and foaming black holes

    SciTech Connect (OSTI)

    Bena, Iosif; Warner, Nicholas P.

    2006-09-15

    We construct smooth BPS three-charge geometries that resolve the zero-entropy singularity of the U(1)xU(1) invariant black ring. This singularity is resolved by a geometric transition that results in geometries without any branes sources or singularities but with nontrivial topology. These geometries are both ground states of the black ring, and nontrivial microstates of the D1-D5-P system. We also find the form of the geometries that result from the geometric transition of N zero-entropy black rings, and argue that, in general, such geometries give a very large number of smooth bound-state three-charge solutions, parametrized by 6N functions. The generic microstate solution is specified by a four-dimensional hyper-Kaehler geometry of a certain signature, and contains a 'foam' of nontrivial two-spheres. We conjecture that these geometries will account for a significant part of the entropy of the D1-D5-P black hole, and that Mathur's conjecture might reduce to counting certain hyper-Kaehler manifolds.

  8. Galaxies nurtured by mature black holes

    E-Print Network [OSTI]

    Morikawa, Masahiro

    2015-01-01

    Supermassive black holes (SMBH) of size $10^{6-10}M_{\\odot}$ are common in the Universe and they define the center of the galaxies. A galaxy and the SMBH are generally thought to have co-evolved. However, the SMBH cannot evolve so fast as commonly observed even at redshift $z>6$. Therefore, we explore a natural hypothesis that the SMBH has been already formed mature at $z\\gtrapprox10$ before stars and galaxies. The SMBH forms energetic jets and outflows which trigger massive star formation in the ambient gas. They eventually construct globular clusters and classical bulge as well as the body of elliptical galaxies. We propose simple models which implement these processes. We point out that the globular clusters and classical bulges have a common origin but are in different phases. The same is true for the elliptical and spiral galaxies. Physics behind these phase division is the runaway star formation process with strong feedback to SMBH. This is similar to the forest-fire model that displays self-organized c...

  9. A hole accelerator for InGaN/GaN light-emitting diodes

    SciTech Connect (OSTI)

    Zhang, Zi-Hui; Liu, Wei; Tan, Swee Tiam; Ji, Yun; Wang, Liancheng; Zhu, Binbin; Zhang, Yiping; Lu, Shunpeng; Zhang, Xueliang; Hasanov, Namig; Sun, Xiao Wei, E-mail: EXWSUN@ntu.edu.sg, E-mail: VOLKAN@stanfordalumni.org [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Demir, Hilmi Volkan, E-mail: EXWSUN@ntu.edu.sg, E-mail: VOLKAN@stanfordalumni.org [LUMINOUS Centre of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, School of Physical and Mathematical Sciences, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Department of Electrical and Electronics, Department of Physics, and UNAM-Institute of Material Science and Nanotechnology, Bilkent University, TR-06800 Ankara (Turkey)

    2014-10-13

    The quantum efficiency of InGaN/GaN light-emitting diodes (LEDs) has been significantly limited by the insufficient hole injection, and this is caused by the inefficient p-type doping and the low hole mobility. The low hole mobility makes the holes less energetic, which hinders the hole injection into the multiple quantum wells (MQWs) especially when a p-type AlGaN electron blocking layer (EBL) is adopted. In this work, we report a hole accelerator to accelerate the holes so that the holes can obtain adequate kinetic energy, travel across the p-type EBL, and then enter the MQWs more efficiently and smoothly. In addition to the numerical study, the effectiveness of the hole accelerator is experimentally shown through achieving improved optical output power and reduced efficiency droop for the proposed InGaN/GaN LED.

  10. Constraining Black Hole Spin Via X-ray Spectroscopy

    E-Print Network [OSTI]

    Laura W. Brenneman; Christopher S. Reynolds

    2006-08-23

    We present an analysis of the observed broad iron line feature and putative warm absorber in the long 2001 XMM-Newton observation of the Seyfert-1.2 galaxy MCG-6-30-15. The new "kerrdisk" model we have designed for simulating line emission from accretion disk systems allows black hole spin to be a free parameter in the fit, enabling the user to formally constrain the angular momentum of a black hole, among other physical parameters of the system. In an important extension of previous work, we derive constraints on the black hole spin in MCG-6-30-15 using a self-consistent model for X-ray reflection from the surface of the accretion disk while simultaneously accounting for absorption by dusty photoionized material along the line of sight (the warm absorber). Even including these complications, the XMM-Newton/EPIC-pn data require extreme relativistic broadening of the X-ray reflection spectrum; assuming no emission from within the radius of marginal stability, we derive a formal constraint on the dimensionless black hole spin parameter of a > 0.987 at 90% confidence. The principal unmodeled effect that can significantly reduce the inferred black hole spin is powerful emission from within the radius of marginal stability. Although significant theoretical developments are required to fully understand this region, we argue that the need for a rapidly spinning black hole is robust to physically plausible levels of emission from within the radius of marginal stability. In particular, we show that a non-rotating black hole is strongly ruled out.

  11. Ehrenfest scheme for $P-V$ criticality of higher dimensional charged black holes, rotating black holes and Gauss-Bonnet AdS black holes

    E-Print Network [OSTI]

    Mo, Jie-Xiong

    2014-01-01

    To provide an analytic verification of the nature of phase transition at the critical point of $P-V$ criticality, the original expressions of Ehrenfest equations have been introduced directly. By treating the cosmological constant and its conjugate quantity as thermodynamic pressure and volume respectively, we carry out analytical check of classical Ehrenfest equations. To show that our approach is universal, we investigate not only higher-dimensional charged AdS black holes, but also rotating AdS black holes. Not only are the examples of Einstein gravity shown, but also the example of modified gravity is presented for Gauss-Bonnet AdS black holes. The specific heat at constant pressure $C_P$, the volume expansion coefficient $\\alpha$ and the isothermal compressibility coefficient $\\kappa_T$ are found to diverge exactly at the critical point. It has been verified that both Ehrenfest equations hold at the critical point of $P-V$ criticality in the extended phase spaces of AdS black holes. So the nature of the ...

  12. Thermodynamics of Three-dimensional Black Holes via Charged Particle Absorption

    E-Print Network [OSTI]

    Gwak, Bogeun

    2015-01-01

    We have shown that changes occur in a (2+1)-dimensional charged black hole by adding a charged probe. The particle increases the entropy of the black hole and guarantees the second law of thermodynamics. The first law of thermodynamics is derived from the change in the black hole mass. Using the particle absorption, we test the extremal black hole and find out that the mass of the extremal black hole increases more than the electric charge. Therefore, the outer horizon of the black hole still exists. However, the extremal condition becomes non-extremal.

  13. Semi-classical approach to quantum black holes

    E-Print Network [OSTI]

    Euro Spallucci; Anais Smailagic

    2014-10-07

    In this Chapter we would like to review a "~phenomenological~" approach taking into account the most fundamental feature of string theory or, more in general, of quantum gravity, whatever its origin, which is the existence of a minimal length in the space-time fabric. This length is generally identified with the Planck length, or the string length, but it could be also much longer down to the TeV region. A simple and effective way to keep track of the effects the minimal length in black hole geometries is to solve the Einstein equations with an energy momentum tensor describing non point-like matter. The immediate consequence is the absence of any curvature singularity. Where textbook solutions of the Einstein equations loose any physical meaning because of infinite tidal forces, we find a de Sitter vacuum core of high, but finite, energy density and pressure. An additional improvement regards the final stage of the black hole evaporation leading to a vanishing Hawking temperature even in the neutral, non-rotating, case. In spite of th simplicity of this model we are able to describe the final stage of the black hole evaporation, resulting in a cold remnant with a degenerate, extremal, horizon of radius of the order of the minimal length. In this chapter we shall describe only neutral, spherically symmetric, regular black holes although charged, rotating and higher dimensional black holes can be found in the literature.

  14. On geodesic dynamics in deformed black-hole fields

    E-Print Network [OSTI]

    Old?ich Semerák; Petra Suková

    2015-09-28

    "Almost all" seems to be known about isolated stationary black holes in asymptotically flat space-times and about the behaviour of {\\em test} matter and fields in their backgrounds. The black holes likely present in galactic nuclei and in some X-ray binaries are commonly being represented by the Kerr metric, but actually they are not isolated (they are detected only thanks to a strong interaction with the surroundings), they are not stationary (black-hole sources are rather strongly variable) and they also probably do not live in an asymptotically flat universe. Such "perturbations" may query the classical black-hole theorems (how robust are the latter against them?) and certainly affect particles and fields around, which can have observational consequences. In the present contribution we examine how the geodesic structure of the static and axially symmetric black-hole space-time responds to the presence of an additional matter in the form of a thin disc or ring. We use several different methods to show that geodesic motion may become chaotic, to reveal the strength and type of this irregularity and its dependence on parameters. The relevance of such an analysis for galactic nuclei is briefly commented on.

  15. Black hole spectroscopy from Loop Quantum Gravity models

    E-Print Network [OSTI]

    Aurelien Barrau; Xiangyu Cao; Karim Noui; Alejandro Perez

    2015-04-21

    Using Monte Carlo simulations, we compute the integrated emission spectra of black holes in the framework of Loop Quantum Gravity (LQG). The black hole emission rates are governed by the entropy whose value, in recent holographic loop quantum gravity models, was shown to agree at leading order with the Bekenstein-Hawking entropy. Quantum corrections depend on the Barbero-Immirzi parameter $\\gamma$. Starting with black holes of initial horizon area $A \\sim 10^2$ in Planck units, we present the spectra for different values of $\\gamma$. Each spectrum clearly decomposes in two distinct parts: a continuous background which corresponds to the semi-classical stages of the evaporation and a series of discrete peaks which constitutes a signature of the deep quantum structure of the black hole. We show that $\\gamma$ has an effect on both parts that we analyze in details. Finally, we estimate the number of black holes and the instrumental resolution required to experimentally distinguish between the considered models.

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

    SciTech Connect (OSTI)

    Myal, F.R.

    1992-05-01

    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.

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

    SciTech Connect (OSTI)

    Myal, F.R.

    1992-05-01

    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.

  18. Mass and Free Energy of Lovelock Black Holes

    E-Print Network [OSTI]

    David Kastor; Sourya Ray; Jennie Traschen

    2011-06-20

    An explicit formula for the ADM mass of an asymptotically AdS black hole in a generic Lovelock gravity theory is presented, identical in form to that in Einstein gravity, but multiplied by a function of the Lovelock coupling constants and the AdS curvature radius. A Gauss' law type formula relates the mass, which is an integral at infinity, to an expression depending instead on the horizon radius. This and other thermodynamic quantities, such as the free energy, are then analyzed in the limits of small and large horizon radius, yielding results that are independent of the detailed choice of Lovelock couplings. In even dimensions, the temperature diverges in both limits, implying the existence of a minimum temperature for black holes. The negative free energy of sufficiently large black holes implies the existence of a Hawking-Page transition. In odd dimensions the temperature still diverges for large black holes, which again have negative free energy. However, the temperature vanishes as the horizon radius tends to zero and sufficiently small black holes have positive specific heat.

  19. Colliding Axion-Dilaton Plane Waves from Black Holes

    E-Print Network [OSTI]

    Patricia Schwarz

    1997-08-01

    The colliding plane wave metric discovered by Ferrari and Iba\\~{n}ez to be locally isometric to the interior of a Schwarzschild black hole is extended to the case of general axion-dilaton black holes. Because the transformation maps either black hole horizon to the focal plane of the colliding waves, this entire class of colliding plane wave spacetimes only suffers from the formation of spacetime singularities in the limits where the inner horizon itself is singular, which occur in the Schwarzschild and dilaton black hole limits. The supersymmetric limit corresponding to the extreme axion-dilaton black hole yields the Bertotti-Robinson metric with the axion and dilaton fields flowing to fixed constant values. The maximal analytic extension of this metric across the Cauchy horizon yields a spacetime in which two sandwich waves in a cylindrical universe collide to produce a semi-infinite chain of Reissner-Nordstrom-like wormholes. The focussing of particle and string geodesics in this spacetime is explored.

  20. The mass function of high redshift seed black holes

    E-Print Network [OSTI]

    Lodato, G; Lodato, Giuseppe; Natarajan, Priyamvada

    2007-01-01

    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 ...

  1. Film Cooling with Forward and Backward Injection for Cylindrical and Fan-shaped Holes Using PSP Measurement Technique 

    E-Print Network [OSTI]

    Chen, Andrew F

    2013-11-08

    effectiveness distributions were obtained using the steady state pressure sensitive paint (PSP) technique. Four common film-hole geometries with forward injection were used in this study: simple angled cylindrical holes and fan-shaped holes, and compound angled...

  2. LIFETIME AND RADIATIVE EFFICIENCY VS DENSITY IN THE STRAIN-CONFINED ELECTRON-HOLE LIQUID IN Ge

    E-Print Network [OSTI]

    Kelso, Susan M.

    2011-01-01

    electron-hole liquid (SCEHL) in Ge. Sample CR50 was T = 1.9CONFINED ELECTRON-HOLE LIQUID IN Ge Susan M. Kelso and JohnCONFINED ELECTRON-HOLE LIQUID IN Ge Susan M. Kelso and John

  3. Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Don Macune

    2008-06-30

    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.

  4. The Quantum Black Hole Specific Heat is Positive

    E-Print Network [OSTI]

    Andrzej Z. Gorski; Pawel O. Mazur

    1997-05-16

    We suggest in this Letter that the Bekenstein-Hawking black hole entropy accounts for the degrees of freedom which are excited at low temperatures only and hence it leads to the negative specific heat. Taking into account the physical degrees of freedom which are excited at high temperatures, the existence of which we postulate, we compute the total specific heat of the quantum black hole that appears to be positive. This is done in analogy to the Planck's treatment of the black body radiation problem. Other thermodynamic functions are computed as well. Our results and the success of the thermodynamic description of the quantum black hole suggest an underlying atomic (discrete) structure of gravitation. The basic properties of these gravitational atoms are found.

  5. Distorted black holes from a vacuum 5-d spherical solution

    E-Print Network [OSTI]

    Capistrano, Abraão J S; Ulhoa, Sergio C; Amorim, Ronni G G

    2015-01-01

    We study the deformation caused by the influence of extrinsic curvature on a vacuum spherically symmetric metric embedded in a 5-d bulk. In this sense, we investigate the produced stationary black-holes and derive general properties such as its mass and horizons. As an application, a test moving particle near such black-holes is also shown as well the distortion caused by extrinsic curvature on its movement. Accordingly, using asymptotically conformal flat condition on the extrinsic curvature and an analytical expansion of a set of \\emph{n}-scalar fields, we show that the resulting black holes must be large and constrained in the range $-1/2 \\leq n \\leq 1.8$ that are locally thermodynamically stable, but not globally preferred.

  6. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Elliot Banks; Aristomenis Donos; Jerome P. Gauntlett

    2015-07-15

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  7. Exploring Higher Dimensional Black Holes at the Large Hadron Collider

    E-Print Network [OSTI]

    C. M. Harris; M. J. Palmer; M. A. Parker; P. Richardson; A. Sabetfakhri; B. R. Webber

    2004-11-01

    In some extra dimension theories with a TeV fundamental Planck scale, black holes could be produced in future collider experiments. Although cross sections can be large, measuring the model parameters is difficult due to the many theoretical uncertainties. Here we discuss those uncertainties and then we study the experimental characteristics of black hole production and decay at a typical detector using the ATLAS detector as a guide. We present a new technique for measuring the temperature of black holes that applies to many models. We apply this technique to a test case with four extra dimensions and, using an estimate of the parton-level production cross section error of 20%, determine the Planck mass to 15% and the number of extra dimensions to +-0.75.

  8. Holographic Superconductors with Ho?ava-Lifshitz Black Holes

    E-Print Network [OSTI]

    Rong-Gen Cai; Hai-Qing Zhang

    2009-12-03

    We discuss the phase transition of planar black holes in Ho\\v{r}ava-Lifshitz gravity by introducing a Maxwell field and a complex scalar field. We calculate the condensates of the charged operators in the dual CFTs when the mass square of the complex scalar filed is $m^2=-2/L^2$ and $m^2=0$, respectively. We compute the electrical conductivity of the \\hl superconductor in the probe approximation. In particular, it is found that there exists a spike in the conductivity for the case of the operator with scaling dimension one. These results are quite similar to those in the case of Schwarzschild-AdS black holes, which demonstrates that the holographic superconductivity is a robust phenomenon associated with asymptotic AdS black holes.

  9. Information Preservation and Weather Forecasting for Black Holes

    E-Print Network [OSTI]

    S. W. Hawking

    2014-01-22

    It has been suggested [1] that the resolution of the information paradox for evaporating black holes is that the holes are surrounded by firewalls, bolts of outgoing radiation that would destroy any infalling observer. Such firewalls would break the CPT invariance of quantum gravity and seem to be ruled out on other grounds. A different resolution of the paradox is proposed, namely that gravitational collapse produces apparent horizons but no event horizons behind which information is lost. This proposal is supported by ADS-CFT and is the only resolution of the paradox compatible with CPT. The collapse to form a black hole will in general be chaotic and the dual CFT on the boundary of ADS will be turbulent. Thus, like weather forecasting on Earth, information will effectively be lost, although there would be no loss of unitarity.

  10. Black hole feedback in the luminous quasar PDS 456

    E-Print Network [OSTI]

    Nardini, E; Gofford, J; Harrison, F A; Risaliti, G; Braito, V; Costa, M T; Matzeu, G A; Walton, D J; Behar, E; Boggs, S E; Christensen, F E; Craig, W W; Hailey, C J; Matt, G; Miller, J M; O'Brien, P T; Stern, D; Turner, T J; Ward, M J

    2015-01-01

    The evolution of galaxies is connected to the growth of supermassive black holes in their centers. During the quasar phase, a huge luminosity is released as matter falls onto the black hole, and radiation-driven winds can transfer most of this energy back to the host galaxy. Over five different epochs, we detected the signatures of a nearly spherical stream of highly ionized gas in the broadband X-ray spectra of the luminous quasar PDS 456. This persistent wind is expelled at relativistic speeds from the inner accretion disk, and its wide aperture suggests an effective coupling with the ambient gas. The outflow's kinetic power larger than 10^46 ergs per second is enough to provide the feedback required by models of black hole and host galaxy co-evolution.

  11. Black hole energy extraction via stationary scalar clouds

    E-Print Network [OSTI]

    Wilson-Gerow, Jordan

    2015-01-01

    We study scalar field configurations around Kerr black holes with a time-independent energy-momentum tensor. These stationary `scalar clouds', confined near the black hole (BH) by their own mass or a mirror at fixed radius, exist at the threshold for energy extraction via superradiance. Motivated by the electromagnetic Blandford-Znajek (BZ) mechanism, we explore whether scalar clouds could serve as a proxy for the force-free magnetosphere in the BZ process. We find that a stationary energy-extracting scalar cloud solution exists when the reflecting mirror is replaced by a semi-permeable surface which allows the cloud to radiate some energy to infinity while maintaining self-sustained superradiance. The radial energy flux displays the same behaviour for rapidly rotating holes as magnetohydrodynamic simulations predict for the BZ mechanism.

  12. Black hole energy extraction via stationary scalar clouds

    E-Print Network [OSTI]

    Jordan Wilson-Gerow; Adam Ritz

    2015-09-22

    We study scalar field configurations around Kerr black holes with a time-independent energy-momentum tensor. These stationary `scalar clouds', confined near the black hole (BH) by their own mass or a mirror at fixed radius, exist at the threshold for energy extraction via superradiance. Motivated by the electromagnetic Blandford-Znajek (BZ) mechanism, we explore whether scalar clouds could serve as a proxy for the force-free magnetosphere in the BZ process. We find that a stationary energy-extracting scalar cloud solution exists when the reflecting mirror is replaced by a semi-permeable surface which allows the cloud to radiate some energy to infinity while maintaining self-sustained superradiance. The radial energy flux displays the same behaviour for rapidly rotating holes as magnetohydrodynamic simulations predict for the BZ mechanism.

  13. Thermodynamics of de Sitter Black Holes: Thermal Cosmological Constant

    E-Print Network [OSTI]

    Yuichi Sekiwa

    2006-04-10

    We study the thermodynamic properties associated with the black hole event horizon and the cosmological horizon for black hole solutions in asymptotically de Sitter spacetimes. We examine thermodynamics of these horizons on the basis of the conserved charges according to Teitelboim's method. In particular, we have succeeded in deriving the generalized Smarr formula among thermodynamical quantities in a simple and natural way. We then show that cosmological constant must decrease when one takes into account the quantum effect. These observations have been obtained if and only if cosmological constant plays the role of a thermodynamical state variable. We also touch upon the relation between inflation of our universe and a phase transition of black holes.

  14. Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenon

    E-Print Network [OSTI]

    Arazi, L; Coimbra, A E C; Rappaport, M L; Vartsky, D; Chepel, V; Breskin, A

    2015-01-01

    In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the scintillation light is generated in xenon bubbles trapped below the THGEM holes. The process is shown to be remarkably stable over months of operation, providing - under specific thermodynamic conditions - energy resolution similar to that of present dual-phase liquid xenon experiments. The observed mechanism may serve as the basis for the development of Liquid Hole Multipliers (LHMs), capable of producing local charge-induced electroluminescence signals in large-volume single-phase noble-liquid detectors for dark matter and neutrino physics experiments.

  15. Liquid Hole Multipliers: bubble-assisted electroluminescence in liquid xenon

    E-Print Network [OSTI]

    L. Arazi; E. Erdal; A. E. C. Coimbra; M. L. Rappaport; D. Vartsky; V. Chepel; A. Breskin

    2015-05-13

    In this work we discuss the mechanism behind the large electroluminescence signals observed at relatively low electric fields in the holes of a Thick Gas Electron Multiplier (THGEM) electrode immersed in liquid xenon. We present strong evidence that the scintillation light is generated in xenon bubbles trapped below the THGEM holes. The process is shown to be remarkably stable over months of operation, providing - under specific thermodynamic conditions - energy resolution similar to that of present dual-phase liquid xenon experiments. The observed mechanism may serve as the basis for the development of Liquid Hole Multipliers (LHMs), capable of producing local charge-induced electroluminescence signals in large-volume single-phase noble-liquid detectors for dark matter and neutrino physics experiments.

  16. Aspects of Accretion Processes On a Rotating Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1996-11-10

    We describe the most general nature of accretion and wind flows around a compact object and emphasize on the properties which are special to black hole accretion. The angular momentum distribution in the most general solution is far from Keplerian, and the non-Keplerian disks can include standing shock waves. We also present fully time dependent numerical simulation results to show that they agree with these analytical solutions. We describe the spectral properties of these accretion disks and show that the soft and hard states of the black hole candidates could be explained by the change of the accretion rate of the disk. We present fits of the observational data to demonstrate the presence of sub-Keplerian flows around black holes.

  17. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Banks, Elliot; Gauntlett, Jerome P

    2015-01-01

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  18. Thermoelectric DC conductivities and Stokes flows on black hole horizons

    E-Print Network [OSTI]

    Elliot Banks; Aristomenis Donos; Jerome P. Gauntlett

    2015-10-11

    We consider a general class of electrically charged black holes of Einstein-Maxwell-scalar theory that are holographically dual to conformal field theories at finite charge density which break translation invariance explicitly. We examine the linearised perturbations about the solutions that are associated with the thermoelectric DC conductivity. We show that there is a decoupled sector at the black hole horizon which must solve generalised Stokes equations for a charged fluid. By solving these equations we can obtain the DC conductivity of the dual field theory. For Q-lattices and one-dimensional lattices we solve the fluid equations to obtain closed form expressions for the DC conductivity in terms of the solution at the black hole horizon. We also determine the leading order DC conductivity for lattices that can be expanded as a perturbative series about translationally invariant solutions.

  19. Hole-boring through clouds for laser power beaming

    SciTech Connect (OSTI)

    Lipinski, R.J. [Sandia National Labs., Albuquerque, NM (United States); Walter, R.F. [W.J. Schafer Associates, Inc., Albuquerque, NM (United States)

    1994-12-31

    Power beaming to satellites with a ground-based laser can be limited by clouds. Hole-boring through the clouds with a laser has been proposed as a way to overcome this obstacle. This paper reviews the past work on laser hole-boring and concludes that hole-boring for direct beaming to satellites is likely to require 10--100 MW. However, it may be possible to use an airborne relay mirror at 10--25 km altitude for some applications in order to extend the range of the laser (e.g., for beaming to satellites near the horizon). In these cases, use of the relay mirror also would allow a narrow beam between the laser and the relay, as well as the possibility of reducing the crosswind if the plane matched speed with the cloud temporarily. Under these conditions, the power requirement to bore a hole through most cirrus and cirrostratus clouds might be only 500-kW if the hole is less than 1 m in diameter and if the crosswind speed is less than 10 m/s. Overcoming cirrus and cirrostratus clouds would reduce the downtime due to weather by a factor of 2. However, 500 kW is a large laser, and it may be more effective instead to establish a second power beaming site in a separate weather zone. An assessment of optimum wavelengths for hole boring also was made, and the best options were found to be 3.0--3.4 {mu}m and above 10 {mu}m.

  20. Thermodynamics of Black Hole Horizons and Kerr/CFT Correspondence

    E-Print Network [OSTI]

    Bin Chen; Shen-xiu Liu; Jia-ju Zhang

    2012-11-02

    In this paper we investigate the thermodynamics of the inner horizon and its implication on the holographic description of the black hole. We focus on the black holes with two physical horizons. Under reasonable assumption, we prove that the first law of thermodynamics of the outer horizon always indicates that of the inner horizon. As a result, the fact that the area product being mass-independent is equivalent to the relation $T_+S_+=T_-S_-$, with $T_\\pm$ and $S_\\pm$ being the Hawking temperatures and the entropies of the outer and inner horizon respectively. We find that the mass-independence of area product breaks down in general Myers-Perry black holes with spacetime dimension $d\\geq6$ and Kerr-AdS black holes with $d\\geq4$. Moreover we discuss the implication of the first laws of the outer and inner horizons on the thermodynamics of the right- and left-moving sectors of dual CFT in Kerr/CFT correspondence. We show that once the relation $T_+S_+=T_-S_-$ is satisfied, the central charges of two sectors must be same. Furthermore from the thermodynamics relations, we read the dimensionless temperatures of microscopic CFT, which are in exact agreement with the ones obtained from hidden conformal symmetry in the low frequency scattering off the black holes, and then determine the central charges. This method works well in well-known cases in Kerr/CFT correspondence, and reproduce successfully the holographic pictures for 4D Kerr-Newman and 5D Kerr black holes. We go on to predict the central charges and temperatures of a possible holographic CFT description dual to 5D doubly rotating black ring.

  1. Improvement of tap holes at Wakayama No. 5 blast furnace

    SciTech Connect (OSTI)

    Yamashita, M.; Kashiwada, M.; Shibuta, H. [Sumitomo Metal Industries, Ltd., Wakayama (Japan). Wakayama Steel Works

    1995-12-01

    The service life of blast furnaces, as the result of various improvement measures, has been extended from the conventional 5 to 7 years to 15 to 20 years. Wakayama No. 5 blast furnace adopted SiC bricks. Though SiC brick excelled in strength and durability, it has raised problems such as tap hole inside temperature lowering attributable to its high thermal conductivity, insufficient mud burning and gas blow-out. Nevertheless, various countermeasures described within have been taken against such problems, and as the result it has now become possible to maintain tap holes in stable conditions.

  2. Exact black hole solution with a minimally coupled scalar field

    E-Print Network [OSTI]

    Cristian Martinez; Ricardo Troncoso; Jorge Zanelli

    2004-06-13

    An exact four-dimensional black hole solution of gravity with a minimally coupled self-interacting scalar field is reported. The event horizon is a surface of negative constant curvature enclosing the curvature singularity at the origin, and the scalar field is regular everywhere outside the origin. This solution is an asymptotically locally AdS spacetime. The strong energy condition is satisfied on and outside the event horizon. The thermodynamical analysis shows the existence of a critical temperature, below which a black hole in vacuum undergoes a spontaneous dressing up with a nontrivial scalar field in a process reminiscent of ferromagnetism.

  3. Regular Black Holes in $f(R)$ Gravity

    E-Print Network [OSTI]

    Rodrigues, Manuel E; Marques, Glauber T; Zanchin, Vilson T

    2015-01-01

    We obtain a class of regular black hole solutions in four-dimensional $f(R)$ gravity, $R$ being the curvature scalar, coupled to a nonlinear electromagnetic source. The metric formalism is used and static spherically symmetric spacetimes are assumed. The resulting metric functions are given by one real parameter family of solutions which are generalization of known regular black hole solutions in General Relativity. The known solutions of General Relativity are recovered when the free parameter vanish in which case one has $f(R)\\propto R$. We show that there are particular cases that violates only the strong energy condition.

  4. Electromagnetic quasinormal modes of D-dimensional black holes II

    E-Print Network [OSTI]

    A. López-Ortega

    2007-06-20

    By using the sixth order WKB approximation we calculate for an electromagnetic field propagating in D-dimensional Schwarzschild and Schwarzschild de Sitter black holes its quasinormal frequencies for the fundamental mode and first overtones. We study the dependence of these QN frequencies on the value of the cosmological constant and the spacetime dimension. We also compare with the known results for the gravitational perturbations propagating in the same background. Moreover we exactly compute the QN frequencies of the electromagnetic field propagating in D-dimensional massless topological black hole and for charged D-dimensional Nariai spacetime we exactly calculate the QN frequencies of the coupled electromagnetic and gravitational perturbations.

  5. Supermassive Black Holes and the Evolution of Galaxies

    E-Print Network [OSTI]

    D. Richstone; E. A. Ajhar; R. Bender; G. Bower; A. Dressler; S. M. Faber; A. V. Filippenko; K. Gebhardt; R. Green; L. C. Ho; J. Kormendy; T. Lauer; J. Magorrian; S. Tremaine

    1998-10-23

    Black holes, an extreme consequence of the mathematics of General Relativity, have long been suspected of being the prime movers of quasars, which emit more energy than any other objects in the Universe. Recent evidence indicates that supermassive black holes, which are probably quasar remnants, reside at the centers of most galaxies. As our knowledge of the demographics of these relics of a violent earlier Universe improve, we see tantalizing clues that they participated intimately in the formation of galaxies and have strongly influenced their present-day structure.

  6. Relativistic Viscous Fluid Description of Microscopic Black Hole Wind

    E-Print Network [OSTI]

    J. I. Kapusta

    2001-05-25

    Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. Whether or not a quasi-stationary shell of matter undergoing radial hydrodynamic expansion surrounds such black holes is been controversial. In this paper relativistic viscous fluid equations are applied to the problem. It is shown that a self-consistent picture emerges of a fluid just marginally kept in local thermal equilibrium; viscosity is a crucial element of the dynamics.

  7. Exploring higher dimensional black holes at the large hadron collider.

    E-Print Network [OSTI]

    Harris, Chris M.; Palmer, M. J.; Parker, Michael A.; Richardson, P.

    Preprint typeset in JHEP style - HYPER VERSION Cavendish-HEP-04/29 ATL-COM-PHYS-2004-067 Exploring Higher Dimensional Black Holes at the Large Hadron Collider C.M. Harris†, M.J. Palmer†, M.A. Parker†, P. Richardson‡, A. Sabetfakhri† and B.R. Webber... the Standard Model matter and gauge fields are confined to the physical three-branes in a higher dimensional space, it has been shown that most of the black hole decay products are Standard Model quanta emitted on the brane [7] and are therefore visible...

  8. Hole cleaning imperative in coiled tubing drilling operations

    SciTech Connect (OSTI)

    Rameswar, R.M.; Mudda, K.

    1995-09-01

    Annular flow modeling in coiled tubing applications is essential for optimizing mud rheology and keeping the hole clean. Cuttings transport in coiled tubing drilling must be optimized, particularly the modeling of hole cleaning capabilities. The effects of two different muds in contrasting geometries on hold cleaning efficiency are considered, with the simulation performed using Petrocalc 14. Coiled tubing is widely used to drill new vertical and horizontal wells, and in re-entry operations. Horizontal well problems are subsequently modeled, where annular eccentricities can range anywhere from concentric to highly offset, given the highly buckled or helically deflected states of many drill coils.

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

    E-Print Network [OSTI]

    A. A. Garcia Diaz; G. Gutierrez Cano

    2014-12-17

    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.

  10. Schwarzschild black hole levitating in the hyperextreme Kerr field

    E-Print Network [OSTI]

    V. S. Manko; E. Ruiz

    2015-11-05

    The equilibrium configurations between a Schwarzschild black hole and a hyperextreme Kerr object are shown to be described by a three-parameter subfamily of the extended double-Kerr solution. For this subfamily, its Ernst potential and corresponding metric functions, we provide a physical representation which employs as arbitrary parameters the individual Komar masses and relative coordinate distance between the sources. The calculation of horizon's local angular velocity induced in the Schwarzschild black hole by the Kerr constituent yields a simple expression inversely proportional to the square of the distance parameter.

  11. Thermodynamics of Schrödinger black holes with hyperscaling violation

    E-Print Network [OSTI]

    J. Sadeghi; B. Pourhassan; F. Pourasadollah

    2012-11-06

    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.

  12. Quantum-corrected finite entropy of noncommutative acoustic black holes

    E-Print Network [OSTI]

    M. A. Anacleto; F. A. Brito; G. C. Luna; E. Passos; J. Spinelly

    2015-01-31

    In this paper we consider the generalized uncertainty principle in the tunneling formalism via Hamilton-Jacobi method to determine the quantum-corrected Hawking temperature and entropy for 2+1-dimensional noncommutative acoustic black holes. In our results we obtain an area entropy, a correction logarithmic in leading order, a correction term in subleading order proportional to the radiation temperature associated with the noncommutative acoustic black holes and an extra term that depends on a conserved charge. Thus, as in the gravitational case, there is no need to introduce the ultraviolet cut-off and divergences are eliminated.

  13. Quantum-corrected finite entropy of noncommutative acoustic black holes

    E-Print Network [OSTI]

    Anacleto, M A; Luna, G C; Passos, E; Spinelly, J

    2015-01-01

    In this paper we consider the generalized uncertainty principle in the tunneling formalism via Hamilton-Jacobi method to determine the quantum-corrected Hawking temperature and entropy for 2+1-dimensional noncommutative acoustic black holes. In our results we obtain an area entropy, a correction logarithmic in leading order, a correction term in subleading order proportional to the radiation temperature associated with the noncommutative acoustic black holes and an extra term that depends on a conserved charge. Thus, as in the gravitational case, there is no need to introduce the ultraviolet cut-off and divergences are eliminated.

  14. Energy distribution in the dyadosphere of a charged black hole

    E-Print Network [OSTI]

    S. S. Xulu

    2003-04-22

    The event horizon of a charged black hole is, according to Ruffini\\cite{Ruffini} and Preparata \\emph{et al.}\\cite{PreparataEtAl}, surrounded by a special region called the \\emph{dyadosphere} where the electromagnetic field exceeds the Euler-Heisenberg critical value for electron-positron pair production. We obtain the energy distribution in the dyadosphere region for a Reissner-Nordstr\\"{o}m black hole. We find that the energy-momentum prescriptions of Einstein, Landau-Lifshitz, Papapetrou, and Weinberg give the same and acceptable energy distribution.

  15. Anomalies, Chern-Simons Terms and Black Hole Entropy

    E-Print Network [OSTI]

    Tatsuo Azeyanagi; R. Loganayagam; Gim Seng Ng

    2015-05-11

    Recent derivations of Cardy-like formulae in higher dimensional field theories have opened up a way of computing, via AdS/CFT, universal contributions to black hole entropy from gravitational Chern-Simons terms. Based on the manifestly covariant formulation of the differential Noether charge for Chern-Simons terms proposed in arXiv:1407.6364, we compute the entropy and asymptotic charges for the rotating charged AdS black holes in higher dimensions at leading order of the fluid/gravity derivative expansion in the Einstein-Maxwell-Chern-Simons system. This gives a result that exactly matches the field theory predictions from Cardy-like formulae.

  16. Greybody factors for Myers–Perry black holes

    SciTech Connect (OSTI)

    Boonserm, Petarpa; Chatrabhuti, Auttakit Ngampitipan, Tritos; Visser, Matt

    2014-11-15

    The Myers–Perry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in Kaluza–Klein models, specifically within the context of brane-world versions thereof. In the present article, we shall consider the greybody factors associated with scalar field excitations of the Myers–Perry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.

  17. Greybody factors for Myers-Perry black holes

    E-Print Network [OSTI]

    Boonserm, Petarpa; Ngampitipan, Tritos; Visser, Matt

    2014-01-01

    The Myers-Perry black holes are higher-dimensional generalizations of the usual (3+1)-dimensional rotating Kerr black hole. They are of considerable interest in Kaluza-Klein models, specifically within the context of brane-world versions thereof. In the present article we shall consider the greybody factors associated with scalar field excitations of the Myers-Perry spacetimes, and develop some rigorous bounds on these greybody factors. These bounds are of relevance for characterizing both the higher-dimensional Hawking radiation, and the super-radiance, that is expected for these spacetimes.

  18. Dimension of holes and high-temperature condensate in Bose--Einstein statistics

    E-Print Network [OSTI]

    V. P. Maslov

    2006-12-22

    We introduce the notion of weight for the lattice dimension and the notion of topological dimension -- hole dimension. The condensate in Bose-holes exists in the case when temperature in not low.

  19. Double-sided microchannel patterning and through-hole production using injection molding of polypropylene

    E-Print Network [OSTI]

    Diaz, Nancy, S. B. Massachusetts Institute of Technology

    2008-01-01

    An experimental study was conducted on injection molded polypropylene parts with microchannels and through-holes. The quality of the microchannels and through-holes was observed with optical microscope and SEM images. A ...

  20. Experimental Test of Hole-Coupled FEL Resonator Designs Using a CW-HeNe Laser

    E-Print Network [OSTI]

    Leemans, W.P.

    2011-01-01

    Proc. 14 th International FEL Conference, Kobe, Japan, 23-24Test of Hole-Coupled FEL Resonator Designs Using a CW-HeNeuse of hole-coupling for FEL's are: I) reasonable coupling

  1. Three-Dimensional Simulation of a Hole-Coupled FEL Oscillator

    E-Print Network [OSTI]

    Krishnagopal, S.

    2008-01-01

    resonator in the presence of FEL gain, M.Xie and K. -J.Kim,Simulation of a Hole-Coupled FEL Oscillator S. KrishnagopalSimulation of a Hole-Coupled FEL Oscillator S. Krishnagopal,

  2. Core Hole Drilling And Testing At The Lake City, California Geothermal...

    Open Energy Info (EERE)

    Core Hole Drilling And Testing At The Lake City, California Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Core Hole Drilling...

  3. Interaction of Supermassive Black Holes with their Stellar and Dark Matter Environments

    E-Print Network [OSTI]

    David Merritt

    2004-10-04

    A review of recent theoretical work on the interactions of supermassive single and binary black holes with their nuclear environments, highlighting ways in which the observed structure of nuclei can be used to constrain the formation history of black holes.

  4. MEMS Materials and Temperature Sensors for Down Hole Geothermal System Monitoring

    E-Print Network [OSTI]

    Wodin-Schwartz, Sarah

    2013-01-01

    Geothermal EnergyThe future of geothermal energy: Impact of enhanceddown-hole monitoring of geothermal energy systems. ASME 2011

  5. Natural Cutoffs effect on Charged Rotating TeV-Scale Black Hole Thermodynamics

    E-Print Network [OSTI]

    M. J. Soleimani; N. Abbasvandi; G. Gopir; Zainol Abidin Ibrahim; Shahidan Radiman; W. A. T Wan Abdullah

    2015-10-15

    We study the thermodynamics of charged rotating black hole in large extra dimensions scenario where quantum gravity effects are taken into account. We consider the effects of minimal length, minimal momentum, and maximal momentum as natural cutoffs on the thermodynamics of charged rotating TeV-scale black holes. In this framework the effect of the angular momentum and charge on the thermodynamics of the black hole are discussed. We focus also on frame dragging and Sagnac effect of the micro black holes.

  6. Process and structures for fabrication of solar cells with laser ablation steps to form contact holes

    DOE Patents [OSTI]

    Harley, Gabriel; Smith, David D; Dennis, Tim; Waldhauer, Ann; Kim, Taeseok; Cousins, Peter John

    2013-11-19

    Contact holes of solar cells are formed by laser ablation to accomodate various solar cell designs. Use of a laser to form the contact holes is facilitated by replacing films formed on the diffusion regions with a film that has substantially uniform thickness. Contact holes may be formed to deep diffusion regions to increase the laser ablation process margins. The laser configuration may be tailored to form contact holes through dielectric films of varying thickness.

  7. Energy Distribution of a Schwarzschild Black Hole in a Magnetic Universe

    E-Print Network [OSTI]

    Irina Radinschi

    2000-10-25

    We obtain the energy distribution of a Schwarzschild black hole in a magnetic universe in the Tolman prescription.

  8. 4d neutral dilatonic black holes and (4+p) dimensional nondilatonic black p-branes

    E-Print Network [OSTI]

    J. R. Morris

    2000-01-11

    It is shown that, in contrast to the case of extreme 4d dilatonic black holes, 4d neutral dilatonic black holes with horizon singularities can not be interpreted as nonsingular nondilatonic black p-branes in (4+p) dimensions, regardless of the number of extra dimensions p. That is, extra dimensions do not remove naked singularities of 4d neutral dilatonic black holes.

  9. Entropy bound of a charged object and electrostatic self-energy in black holes

    E-Print Network [OSTI]

    B. Linet

    1999-11-30

    Without pretending to any rigour, we find a general expression of the electrostatic self-energy in static black holes with spherical symmetry. We determine the entropy bound of a charged object by assuming the existence of thermodynamics for these black holes. By combining these two results, we show that the entropy bound does not depend on the considered black hole.

  10. Entropy Product Formula for spinning BTZ Black Hole

    E-Print Network [OSTI]

    Pradhan, Parthapratim

    2015-01-01

    We investigate the thermodynamic properties of inner and outer horizons in the background of spinning BTZ(Ba\\~{n}ados,Teitelboim and Zanelli) black hole. We compute the \\emph{horizon radii product, the entropy product, the surface temperature product, the Komar energy product and the specific heat product} for both the horizons. We observe that the entropy product is \\emph{universal}(mass-independent), whereas the surface temperature product, Komar energy product and specific heat product are \\emph{not universal} because they all depends on mass parameter. We also show that the \\emph{First law} of black hole thermodynamics and \\emph {Smarr-Gibbs-Duhem } relations hold for inner horizon as well as outer horizon. The Christodoulou-Ruffini mass formula is derived for both the horizons. We further study the \\emph{stability} of such black hole by computing the specific heat for both the horizons. It has been observed that under certain condition the black hole possesses \\emph{second order phase transition}.

  11. Entropy Product Formula for spinning BTZ Black Hole

    E-Print Network [OSTI]

    Parthapratim Pradhan

    2015-09-02

    We investigate the thermodynamic properties of inner and outer horizons in the background of spinning BTZ(Ba\\~{n}ados,Teitelboim and Zanelli) black hole. We compute the \\emph{horizon radii product, the entropy product, the surface temperature product, the Komar energy product and the specific heat product} for both the horizons. We observe that the entropy product is \\emph{universal}(mass-independent), whereas the surface temperature product, Komar energy product and specific heat product are \\emph{not universal} because they all depends on mass parameter. We also show that the \\emph{First law} of black hole thermodynamics and \\emph {Smarr-Gibbs-Duhem } relations hold for inner horizon as well as outer horizon. The Christodoulou-Ruffini mass formula is derived for both the horizons. We further study the \\emph{stability} of such black hole by computing the specific heat for both the horizons. It has been observed that under certain condition the black hole possesses \\emph{second order phase transition}.

  12. Topological black holes in Lovelock-Born-Infeld gravity

    SciTech Connect (OSTI)

    Dehghani, M. H.; Alinejadi, N.; Hendi, S. H.

    2008-05-15

    In this paper, we present topological black holes of third order Lovelock gravity in the presence of cosmological constant and nonlinear electromagnetic Born-Infeld field. Depending on the metric parameters, these solutions may be interpreted as black hole solutions with inner and outer event horizons, an extreme black hole or naked singularity. We investigate the thermodynamics of asymptotically flat solutions and show that the thermodynamic and conserved quantities of these black holes satisfy the first law of thermodynamic. We also endow the Ricci flat solutions with a global rotation and calculate the finite action and conserved quantities of these class of solutions by using the counterterm method. We compute the entropy through the use of the Gibbs-Duhem relation and find that the entropy obeys the area law. We obtain a Smarr-type formula for the mass as a function of the entropy, the angular momenta, and the charge, and compute temperature, angular velocities, and electric potential and show that these thermodynamic quantities coincide with their values which are computed through the use of geometry. Finally, we perform a stability analysis for this class of solutions in both the canonical and the grand-canonical ensemble and show that the presence of a nonlinear electromagnetic field and higher curvature terms has no effect on the stability of the black branes, and they are stable in the whole phase space.

  13. Unconventional Gravitational Excitation of a Schwarzschild Black Hole

    E-Print Network [OSTI]

    P. T. Leung; Alec Maassen van den Brink; K. W. Mak; K. Young

    2003-03-24

    Besides the well-known quasinormal modes, the gravitational spectrum of a Schwarzschild black hole also has a continuum part on the negative imaginary frequency axis. The latter is studied numerically for quadrupole waves. The results show unexpected striking behavior near the algebraically special frequency $\\Omega=-4i$. This reveals a pair of unconventional damped modes very near $\\Omega$, confirmed analytically.

  14. Dynamical mass ejection from black hole-neutron star binaries

    E-Print Network [OSTI]

    Koutarou Kyutoku; Kunihito Ioka; Hirotada Okawa; Masaru Shibata; Keisuke Taniguchi

    2015-08-19

    We investigate properties of material ejected dynamically in the merger of black hole-neutron star binaries by numerical-relativity simulations. We systematically study the dependence of ejecta properties on the mass ratio of the binary, spin of the black hole, and equation of state of the neutron-star matter. Dynamical mass ejection is driven primarily by tidal torque, and the ejecta is much more anisotropic than that from binary neutron star mergers. In particular, the dynamical ejecta is concentrated around the orbital plane with a half opening angle of 10--20deg and often sweeps out only a half of the plane. The ejecta mass can be as large as ~0.1M_sun, and the velocity is subrelativistic with ~0.2--0.3c for typical cases. The ratio of the ejecta mass to the bound mass (disk and fallback components) is larger, and the ejecta velocity is larger, for larger values of the binary mass ratio, i.e., for larger values of the black-hole mass. The remnant black hole-disk system receives a kick velocity of O(100)km/s due to the ejecta linear momentum, and this easily dominates the kick velocity due to gravitational radiation. Structures of postmerger material, velocity distribution of the dynamical ejecta, fallback rates, and gravitational waves are also investigated. We also discuss the effect of ejecta anisotropy on electromagnetic counterparts, specifically a macronova/kilonova and synchrotron radio emission, developing analytic models.

  15. Orthogonal Cooling hole in a Cross-Elton Freeman

    E-Print Network [OSTI]

    Tennessee, University of

    Orthogonal Cooling hole in a Cross- flow Jet Elton Freeman CFD Colloquium May 18th 2010 #12;Thin film cooling is one of the newest techniques to improve turbine combustion engine performance width is given as Smaginorsky Constants are: Cs = 0.1 to 0.2 #12;Model for combustion in general: C3H8

  16. Small diameter horizontal hole drilling - state of technology

    SciTech Connect (OSTI)

    NONE

    1984-11-01

    The purpose of this study is to determine the existing state of the art for small diameter, horizontal pilot hole drilling. The data were collected by contacting worldwide owners of raise or slant hole drill equipment, manufacturers of drills and bits, and manufacturers of survey tools. The study was limited to existing equipment and completed trials. Most attempts at directional pilot hole drilling, and most survey tools are designed for near vertical, downward drilling. Several types of controllable bits are available which depend upon in-hole motors and bent or wedged assemblies to bias the direction of drilling. Accurate horizontal drilling can be achieved in this way by alternately drilling and surveying at frequent intervals. This procedure is impractical, however, from both a production and a cost standpoint. A few attempts at directional drilling have been made using ordinary drilling tools, a rotary drill string and a tricone bit. Good equipment and a well trained drill crew appeared to be the most significant factor in practical, accurate drilling, whether horizontal or vertical. Because of the cost, no one uses steerable bit drilling except for correction, and then only for short portions of an overall drill program. No satisfactory continuous readout surveying tool, coupled with a remotely controlled bit capable of direction correction, exists. An industry need exists for a high speed, directional drill bit, coupled with a continuously monitored survey tool. 2 tables.

  17. A Unitary Model of The Black Hole Evaporation

    E-Print Network [OSTI]

    Yu-Lei Feng; Yi-Xin Chen

    2014-12-16

    A unitary effective field model of the black hole evaporation is proposed to satisfy almost the four postulates of the black hole complementarity (BHC). In this model, we enlarge a black hole-scalar field system by adding an extra radiation detector that couples with the scalar field. After performing a partial trace over the scalar field space, we obtain an effective entanglement between the black hole and the detector (or radiation in it). As the whole system evolves, the S-matrix formula can be constructed formally step by step. Without local quantum measurements, the paradoxes of the information loss and AMPS's firewall can be resolved. However, the information can be lost due to quantum decoherence, as long as some local measurement has been performed on the detector to acquire the information of the radiation in it. But unlike Hawking's completely thermal spectrum, some residual correlations can be found in the radiations. All these considerations can be simplified in a qubit model that provides a \\emph{modified quantum teleportation} to transfer the information via an EPR pairs.

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

    E-Print Network [OSTI]

    Hugues Beauchesne; Ariel Edery

    2012-05-19

    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.

  19. Fatigue Enhancement of Undersized, Drilled Crack-Stop Holes

    E-Print Network [OSTI]

    Crain, Joshua Sakumura

    2010-04-20

    A common technique used to prevent the propagation of cracks in bridge girders is drilling crack-stop holes at the crack tips. By doing so, stress concentrations at the tip of the cracks are reduced and fatigue life of the ...

  20. A Mechanism for Detecting Gray Hole Attacks on Synchrophasor Data

    E-Print Network [OSTI]

    Sikdar, Biplab

    in smart grids [1]. Phasor measurement unit (PMU) or synchrophasor data serves to facilitate a number in the maintenance and control of the power generation and distribution system, monitoring and manipulation of PMU. This paper addresses the problem of securing PMU data against packet dropping or gray hole attacks

  1. Bulk emission of scalars by a rotating black hole

    E-Print Network [OSTI]

    M. Casals; S. R. Dolan; P. Kanti; E. Winstanley

    2008-07-17

    We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane. We present accurate bulk-to-brane emission ratios for a range of scenarios.

  2. Relative importance of radical families The "Ozone Hole"

    E-Print Network [OSTI]

    Toohey, Darin W.

    · Relative importance of radical families · The "Ozone Hole" · Introduction to heterogeneous chemistry Tuesday, March 8, 2011 #12;Review of important points so far Stratospheric ozone is only produced with these parameters Sir Sydney Chapman nearly got it right. He could account for the formation of the ozone layer

  3. Quantum Jump from Singularity to Outside of Black Hole

    E-Print Network [OSTI]

    Dündar, Furkan Semih

    2015-01-01

    Considering the role of black hole singularity in quantum evolution, a resolution to the firewall paradox is presented. It is emphasized that if an observer has the singularity as a part of his spacetime, then the semi-classical evolution would be non-unitary as viewed by him. Specifically, a free-falling observer inside the black hole would have a Hilbert space with non-unitary evolution; a quantum jump for particles encountering the singularity to outside of the horizon as part of late radiations in black hole evaporation. Accordingly, we elaborate the first postulate of black hole complementarity: freely falling observers who pass through the event horizon would have non-unitarity evolutions. The non-unitary evolution is such that it does not have physically measurable effects for them. Besides, no information would be lost in singularity. Taking the modified picture into account, the firewall paradox {can be} resolved, respecting No Drama. A by-product of our modification is that roughly half of the mass ...

  4. Head-on collisions of black holes: the particle limit

    E-Print Network [OSTI]

    Carlos O. Lousto; Richard H. Price

    1996-09-05

    We compute gravitational radiation waveforms, spectra and energies for a point particle of mass $m_0$ falling from rest at radius $r_0$ into a Schwarzschild hole of mass $M$. This radiation is found to lowest order in $(m_0/M)$ with the use of a Laplace transform. In contrast with numerical relativity results for head-on collisions of equal-mass holes, the radiated energy is found not to be a monotonically increasing function of initial separation; there is a local radiated-energy maximum at $r_0\\approx4.5M$. The present results, along with results for infall from infinity, provide a complete catalog of waveforms and spectra for particle infall. We give a representative sample from that catalog and an interesting observation: Unlike the simple spectra for other head-on collisions (either of particle and hole, or of equal mass holes) the spectra for $\\infty>r_0>\\sim5M$ show a series of evenly spaced bumps. A simple explanation is given for this. Lastly, our energy vs. $r_0$ results are compared with approximation methods used elsewhere, for small and for large initial separation.

  5. THE FIRST ACCURATE PARALLAX DISTANCE TO A BLACK HOLE

    E-Print Network [OSTI]

    Miller-Jones, J. C. A.

    Using astrometric VLBI observations, we have determined the parallax of the black hole X-ray binary V404 Cyg to be 0.418 [plus or minus sign] 0.024 mas, corresponding to a distance of 2.39 [plus or minus sign] 0.14 kpc, ...

  6. Horizon of quantum black holes in various dimensions

    E-Print Network [OSTI]

    Casadio, Roberto; Giugno, Andrea; Mureika, Jonas

    2015-01-01

    We adapt the horizon wave-function formalism to describe massive static spherically symmetric sources in a general $(1+D)$-dimensional space-time, for $D>3$ and including the $D=1$ case. We find that the probability $P_{\\rm BH} $ that such objects are (quantum) black holes behaves similarly to the probability in the $(3+1)$ framework for $D> 3$. In fact, for $D\\ge 3$, the probability increases towards unity as the mass grows above the relevant $D$-dimensional Planck scale $m_D$, the faster the larger $D$. In contrast, for $D=1$, we find the probability is comparably larger for smaller masses, but $P_{\\rm BH} < 0.5$, suggesting that such lower dimensional black holes are purely quantum and not classical objects. This result is consistent with recent observations that sub-Planckian black holes are governed by an effective two-dimensional gravitation theory. Lastly, we derive Generalised Uncertainty Principle relations for the black holes under consideration, and for all cases find a minimum length scale $L_D...

  7. Reissner-Nordstrom black hole in dark energy background

    E-Print Network [OSTI]

    Ngangbam Ishwarchandra; Ng. Ibohal; K. Yugindro Singh

    2014-11-29

    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.

  8. Small, dark, and heavy: But is it a black hole?

    E-Print Network [OSTI]

    Visser, Matt; Liberati, Stefano; Sonego, Sebastiano

    2009-01-01

    Astronomers have certainly observed things that are small, dark, and heavy. But are these objects really black holes in the sense of general relativity? The consensus opinion is simply "yes", and there is very little "wriggle room". We discuss one of the specific alternatives.

  9. Sensitivity of HAWC to Primordial Black Hole Bursts

    E-Print Network [OSTI]

    Ukwatta, T N; MacGibbon, D Stump J H; Marinelli, S S; Yapici, T; Tollefson, K

    2015-01-01

    Primordial Black Holes (PBHs) are black holes that may have been created in the early Universe and could be as large as supermassive black holes or as small as the Planck scale. It is believed that a black hole has a temperature inversely proportional to its mass and will thermally emit all species of fundamental particles. PBHs with initial masses of 5.0 x 10^14 g should be expiring today with bursts of high-energy gamma radiation in the GeV/TeV energy range. The High Altitude Water Cherenkov (HAWC) observatory is sensitive to the high end of the PBH gamma-ray burst spectrum. Due to its large field of view, duty cycle above 90% and sensitivity up to 100 TeV, the HAWC observatory is well suited to perform a search for PBH bursts. We report that if the PBH explodes within 0.25 light years from Earth and within 26 degrees of zenith, HAWC will have a 95% probability of detecting the PBH burst at the 5 sigma level. Conversely, a null detection from a 2 year or longer HAWC search will set PBH upper limits which ar...

  10. Zero Energy Rotating Accretion Flows near a Black Hole

    E-Print Network [OSTI]

    Dongsu Ryu; Sandip K. Chakrabarti; Diego Molteni

    1996-07-11

    We characterize the nature of thin, axisymmetric, inviscid, accretion flows of cold adiabatic gas with zero specific energy in the vicinity of a black hole by the specific angular momentum. Using two-dimensional hydrodynamic simulations in cylindrical geometry, we present various regimes in which the accretion flows behave distinctly differently. When the flow has a small angular momentum $(\\lambda\\lsim\\lambda_b)$, most of the material is accreted into the black hole forming a quasi-spherical flow or a simple disk-like structure around it. When the flow has a large angular momentum (typically, larger than the marginally bound value, $\\lambda\\gsim\\lambda_{mb}$), almost no accretion into the black hole occurs. Instead, the flow produces a stable standing shock with one or more vortices behind it and is deflected away at the shock as a conical outgoing wind of higher entropy. If the flow has an angular momentum somewhat smaller than $\\lambda_{mb}$ $(\\lambda_{u}\\lsim\\lambda\\lsim\\lambda_{mb})$, a fraction (typically, $5-10$\\%) of the incoming material is accreted into the black hole, but the the flow structure formed is similar to that as for $\\lambda\\gsim\\lambda_{mb}$. Some of the deflected material is accreted back into the black hole, while the rest is blown away as an outgoing wind. These two cases with $\\lambda\\gsim\\lambda_u$ correspond those studied in the previous works by Molteni, Lanzafame, \\& Chakrabarti (1994) and Ryu \\etal (1995). However, the flow with an angular momentum close to the marginally stable value $(\\lambda_{ms})$ is found to be unstable. More specifically, if $\\lambda_b\\lsim\\lambda\\sim\\lambda_{ms}\\lsim\\lambda_u$, the flow displays a distinct periodicity in the sense that the inner part of the disk is built and

  11. New solutions of exotic charged black holes and their stability

    E-Print Network [OSTI]

    N. Farhangkhah

    2015-10-18

    We find a class of charged black hole solutions in third order Lovelock Gravity. To obtain this class of solutions, we are not confined to the usual assumption of maximal symmetry on the horizon and will consider the solution whose boundary is Einstein space with supplementary conditions on its Weyl tensor. The Weyl tensor of such exotic horizons exposes two charge-like parameter to the solution. These parameters in addition with the electric charge, cause different features in compare with the charged solution with constant-curvature horizon. For this class of asymptotically flat and (A)dS solutions, the electric charge dominates the behavior of the metric as r goes to zero, and thus the central singularity is always timelike. We also compute the thermodynamic quantities for these solutions and will show that the first law of thermodynamics is satisfied. We also show that the extreme black holes with nonconstant-curvature horizons whose Ricci scalar are zero or a positive constant could exist depending on the value of the electric charge and charged-like parameters. Finally, we investigate the stability of the black holes by analyzing the behavior of free energy and heat capacity specially in the limits of small and large horizon radius. We will show that in contrast with charged solution with constant-curvature horizon, a phase transition occurs between very small and small black holes from a stable phase to an unstable one, while the large black holes show stability to both perturbative and non-perturbative fluctuations. ?

  12. The Hawking cascade from a black hole is extremely sparse

    E-Print Network [OSTI]

    Finnian Gray; Sebastian Schuster; Alexander Van-Brunt; Matt Visser

    2015-06-12

    The Hawking flux from a black hole, (at least as seen from large distances), is extremely sparse and thin, with the average time between emission of successive Hawking quanta being hundreds of times larger than the natural timescale set by the energies of the emitted quanta. Some aspects of this result have been known for over 30 years, but have been largely forgotten, possibly because authors focussed mainly on the late-time high-temperature regime. We shall instead focus on the early-stage low-temperature regime, and shall both quantify and significantly extend these observations in a number of different ways. First we shall identify several natural dimensionless figures of merit, and thereby compare the mean time between emission of successive Hawking quanta to several quite natural timescales that can be associated with the emitted quanta, demonstrating that ratios of 300 or more are typical for emission of photons or gravitons from a Schwarzschild black hole. Furthermore these ratios are independent of the mass of the black hole as it slowly evolves. The situation for fermion emission (massless neutrinos) is actually worse. Second, we shall then show that the situation for Reissner-Nordstrom, Kerr, Kerr-Newman and "dirty" black holes is even worse. Third, we consider the effects of particle rest mass. Overall, the Hawking quanta are seen to be dribbling out of the black hole one at a time, in an extremely slow cascade of 3-body decays. This implies that the Hawking flux is subject to "shot noise". Observationally, the Planck spectrum of the Hawking flux can only be determined by collecting and integrating data over a very long time. We conclude by connecting these points back to various kinematic aspects of the Hawking evaporation process.

  13. 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

    2005-06-13

    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)

  14. Optical properties of black hole in the presence of plasma: shadow

    E-Print Network [OSTI]

    Atamurotov, Farruh

    2015-01-01

    Photon motion around the black hole surrounded with a homogenous plasma is studied. It is shown that under influence of plasma the observed size of shadow of the spherical symmetric black hole becomes smaller than that in the vacuum case. However the photon sphere around the spherical symmetric black hole is left unchanged under the plasma influence. The energy emission from the black hole in plasma is also studied and it is shown that with the increase of the dimensionless plasma parameter the maximum value of energy emission rate from the black hole decreases.

  15. Hawking Radiation of Topological Massive Warped-AdS3 Black Hole Families

    E-Print Network [OSTI]

    Ganim Gecim; Yusuf Sucu

    2014-10-15

    We investigate the Dirac particles tunnelling as a radiation of Warped AdS$_{3}$ black hole family in Topological Massive Gravity. Using the Hamilton-Jacobi method, we discuss tunnelling probability and Hawking temperature of the spin-1/2 particles for the black hole and its extremal cases. We observe that the Hawking temperature of the non-extremal black hole higher than the extremal black hole when $\\omega <\\frac{2\\ r_{0}}{3}$, because the non-extremal black hole become unstable in this case.

  16. A comparative study of Dirac quasinormal modes of charged black holes in higher dimensions

    E-Print Network [OSTI]

    Sayan K. Chakrabarti

    2009-03-26

    In this work we study the Dirac quasinormal modes of higher dimensional charged black holes. Higher dimensional Reissner-N\\"{o}rdstrom type black holes as well as charged black holes in Einstein Gauss-Bonnet theories are studied for Fermionic perturbations using WKB method. A comparative study of the quasinormal modes in the two different theories of gravity has been performed. The beahviour of the frequencies with the variation of black hole parameters as well as with the variation of spacetime dimensions are done. We also study the large multipole number limit of the black hole potential in order to look for an analytic expression for the frequencies.

  17. A comparison of black hole growth in galaxy mergers with Gasoline and Ramses

    E-Print Network [OSTI]

    Gabor, J M; Volonteri, Marta; Bournaud, Frédéric; Bellovary, Jillian; Governato, Fabio; Quinn, Thomas

    2015-01-01

    Supermassive black hole dynamics during galaxy mergers is crucial in determining the rate of black hole mergers and cosmic black hole growth. As simulations achieve higher resolution, it becomes important to assess whether the black hole dynamics is influenced by the treatment of the interstellar medium in different simulation codes. We here compare simulations of black hole growth in galaxy mergers with two codes: the Smoothed Particle Hydrodynamics code Gasoline, and the Adaptive Mesh Refinement code Ramses. We seek to identify predictions of these models that are robust despite differences in hydrodynamic methods and implementations of sub-grid physics. We find that the general behavior is consistent between codes. Black hole accretion is minimal while the galaxies are well-separated (and even as they "fly-by" within 10 kpc at first pericenter). At late stages, when the galaxies pass within a few kpc, tidal torques drive nuclear gas inflow that triggers bursts of black hole accretion accompanied by star fo...

  18. Selected stratigraphic data for drill holes located in Frenchman Flat, Nevada Test Site. Rev. 1

    SciTech Connect (OSTI)

    Drellack, S.L. Jr.

    1997-02-01

    Stratigraphic data are presented in tabular form for 72 holes drilled in Frenchman Flat, Nevada Test Site, between 1950 and 1993. Three pairs of data presentations are included for each hole: depth to formation tops, formation thicknesses, and formation elevations are presented in both field (English) and metric units. Also included for each hole, where available, are various construction data (hole depth, hole diameter, surface location coordinates) and certain information of hydrogeologic significance (depth to water level, top of zeolitization). The event name is given for holes associated with a particular nuclear test. An extensive set of footnotes is included, which indicates data sources and provides other information. The body of the report describes the stratigraphic setting of Frenchman Flat, gives drill-hole naming conventions and database terminology, and provides other background and reference material.

  19. Global General Relativistic MHD Simulation of a Tilted Black-Hole Accretion Disk

    E-Print Network [OSTI]

    Fragile, P Chris; Anninos, Peter; Salmonson, Jay D

    2007-01-01

    This paper presents a continuation of our efforts to numerically study accretion disks that are misaligned (tilted) with respect to the rotation axis of a Kerr black hole. Here we present results of a global numerical simulation which fully incorporates the effects of the black hole spacetime as well as magnetorotational turbulence that is the primary source of angular momentum transport in the flow. This simulation shows dramatic differences from comparable simulations of untilted disks. Accretion onto the hole occurs predominantly through two opposing plunging streams that start from high latitudes with respect to both the black-hole and disk midplanes. This is due to the aspherical nature of the gravitational spacetime around the rotating black hole. These plunging streams start from a larger radius than would be expected for an untilted disk. In this regard the tilted black hole effectively acts like an untilted black hole of lesser spin. Throughout the duration of the simulation, the main body of the dis...

  20. The Association of Jet Production with Geometrically Thick Accretion Flows and Black Hole Rotation

    E-Print Network [OSTI]

    David L. Meier

    2000-10-12

    A model is presented in which the strongest radio-emitting jet outflows are produced in black hole systems when the accretion is a geometrically thick ($H/R \\sim 1$) inflow ({\\it e.g.}, ADAF, CDAF) {\\em and} if the black hole is rotating. For galactic black hole candidates, the model naturally accounts for the observed correlation of jet outflow with the black hole hard emission state and predicts an association of strong jets with rapid black hole rotation. When extended to the supermassive case, the model accounts for the highest radio galaxy and quasar jet powers and provides additional theoretical support for the ``spin paradigm'', which asserts that radio loud quasars are produced by Kerr holes and radio quiet ones by Schwarzschild holes. In some cases, the angular momentum and energy outflow in the jet may be large enough to significantly alter the structure of the accretion flow from that predicted by current models.

  1. Electrodeposited cobalt sulfide hole collecting layer for polymer solar cells

    SciTech Connect (OSTI)

    Zampetti, Andrea; De Rossi, Francesca; Brunetti, Francesca; Reale, Andrea; Di Carlo, Aldo; Brown, Thomas M., E-mail: thomas.brown@uniroma2.it [CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome “Tor Vergata,” Via del Politecnico 1, 00133 Rome (Italy)

    2014-08-11

    In polymer solar cells based on the blend of regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester, the hole collecting layer has to be endowed with its ionization potential close to or greater than that of P3HT (?5?eV). Conductive polymer blends such as poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and metal oxides such as vanadium pentoxide (V{sub 2}O{sub 5}) and molybdenum trioxide (MoO{sub 3}) satisfy this requirement and have been the most common materials used so far in bulk heterojunction structures. We report here cobalt sulfide (CoS) to be a promising hole collecting material deposited by convenient and room temperature electrodeposition. By simply tuning the CoS electrodeposition parameters, power conversion efficiencies similar (within 15%) to a reference structure with PEDOT:PSS were obtained.

  2. Primordial Black Holes: Observational Characteristics of The Final Evaporation

    E-Print Network [OSTI]

    Ukwatta, T N; Linnemann, J T; MacGibbon, J H; Marinelli, S S; Yapici, T; Tollefson, K

    2015-01-01

    Many early universe theories predict the creation of Primordial Black Holes (PBHs). PBHs could have masses ranging from the Planck mass to $10^5$ solar masses or higher depending on the size of the universe at formation. A Black Hole (BH) has a Hawking temperature which is inversely proportional to its mass. Hence a sufficiently small BH will quasi-thermally radiate particles at an ever-increasing rate as emission lowers its mass and raises its temperature. The final moments of this evaporation phase should be explosive and its description dependent on the particle physics model. In this work we investigate the final few seconds of BH evaporation using the Standard Model of particle physics incorporating the most recent LHC results and calculate energy dependent PBH burst light curves in the GeV/TeV energy range. Moreover, we explore PBH burst search methods and potential observational PBH burst signatures relevant to very high energy gamma-ray observatories.

  3. Instability of black hole formation in gravitational collapse

    SciTech Connect (OSTI)

    Joshi, Pankaj S.; Malafarina, Daniele

    2011-01-15

    We consider here the classic scenario given by Oppenheimer, Snyder, and Datt, for the gravitational collapse of a massive matter cloud, and examine its stability under the introduction of small tangential stresses. We show, by offering an explicit class of physically valid tangential stress perturbations, that an introduction of tangential pressure, however small, can qualitatively change the final fate of collapse from a black hole final state to a naked singularity. This shows instability of black hole formation in collapse and sheds important light on the nature of cosmic censorship hypothesis and its possible formulations. The key effect of these perturbations is to alter the trapped surface formation pattern within the collapsing cloud and the apparent horizon structure. This allows the singularity to be visible, and implications are discussed.

  4. Circularization of Tidally Disrupted Stars around Spinning Supermassive Black Holes

    E-Print Network [OSTI]

    Hayasaki, Kimitake; Loeb, Abraham

    2015-01-01

    We study the circularization of tidally disrupted stars on bound orbits around spinning supermassive black holes by performing three-dimensional smoothed particle hydrodynamic simulations with Post-Newtonian corrections. Our simulations reveal that debris circularization depends sensitively on the efficiency of radiative cooling. There are two stages in debris circularization if radiative cooling is inefficient: first, the stellar debris streams self-intersect due to relativistic apsidal precession; shocks at the intersection points thermalize orbital energy and the debris forms a geometrically thick, ring-like structure around the black hole. The ring rapidly spreads via viscous diffusion, leading to the formation of a geometrically thick accretion disk. In contrast, if radiative cooling is efficient, the stellar debris circularizes due to self-intersection shocks and forms a geometrically thin ring-like structure. In this case, the dissipated energy can be emitted during debris circularization as a precurso...

  5. Proton Hole States of Nb,95,97,99 

    E-Print Network [OSTI]

    Bindal, P. K.; Youngblood, David H.; Kozub, R. L.

    1974-01-01

    } reactions on 98'98'~ Mo have been used at 40.7 MeV bombarding energy to popul, ate proton hole states in the Nb isotopes. Ten groups of level, s were observed in each nucl. eus and most of the expected strength in the 1g@2, 2p&y2, 2p3g2, and 1f&g2 orbits... was ob- served. Excitation energies and / values were obtained for nine new excited levels in 99Nb. The Q value for the ~00Mo(d, 3He)99Nb reaction was measured to be -5.639+ 0.015 MeV, giv- ing a 99Nb mass excess of -82 342 +15 keV. A hole...

  6. Measurement of Mass and Spin of Black Holes with QPOs

    E-Print Network [OSTI]

    B. Aschenbach

    2007-10-18

    There are now four low mass X-ray binaries with black holes which show twin resonant-like HFQPOs. Similar QPOs might have been found in Sgr A*. I review the power spectral density distributions of the three X-ray flares and the six NIR flares published for Sgr A* so far, in order to look for more similarities than just the frequencies between the microquasar black holes and Sgr A*. The three X-ray flares of Sgr A* are re-analysed in an identical way and white noise probabilities from their power density distributions are given for the periods reported around 1100 s. Progress of the resonant theory using the anomalous orbital velocity effect is summarized.

  7. Powering AGNs with super-critical black holes

    E-Print Network [OSTI]

    A. Avgoustidis; R. Jimenez; L. Alvarez-Gaume; M. A. Vazquez-Mozo

    2009-05-13

    We propose a novel mechanism for powering the central engines of Active Galactic Nuclei through super-critical (type II) black hole collapse. In this picture, ~$10^3 M_\\odot$ of material collapsing at relativistic speeds can trigger a gravitational shock, which can eject a large percentage of the collapsing matter at relativistic speeds, leaving behind a "light" black hole. In the presence of a poloidal magnetic field, the plasma collimates along two jets, and the associated electron synchrotron radiation can easily account for the observed radio luminosities, sizes and durations of AGN jets. For Lorentz factors of order 100 and magnetic fields of a few hundred $\\mu G$, synchrotron electrons can shine for $10^6$ yrs, producing jets of sizes of order 100 kpc. This mechanism may also be relevant for Gamma Ray Bursts and, in the absence of magnetic field, supernova explosions.

  8. Small drill-hole, gas mini-permeameter probe

    DOE Patents [OSTI]

    Molz, III, Fred J. (Seneca, SC); Murdoch, Lawrence C. (Clemson, SC); Dinwiddie, Cynthia L. (Central, SC); Castle, James W. (Clemson, SC)

    2002-01-01

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

  9. Small drill-hole, gas mini-permeameter probe

    DOE Patents [OSTI]

    Molz, III, Fred J.; Murdoch, Lawrence C.; Dinwiddie, Cynthia L.; Castle, James W.

    2002-12-03

    The distal end of a basic tube element including a stopper device with an expandable plug is positioned in a pre-drilled hole in a rock face. Rotating a force control wheel threaded on the tube element exerts force on a sleeve that in turn causes the plug component of the stopper means to expand and seal the distal end of the tube in the hole. Gas under known pressure is introduced through the tube element. A thin capillary tube positioned in the tube element connects the distal end of the tube element to means to detect and display pressure changes and data that allow the permeability of the rock to be determined.

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

    E-Print Network [OSTI]

    Herdeiro, Carlos A R

    2015-01-01

    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.

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

    E-Print Network [OSTI]

    Carlos A. R. Herdeiro; Eugen Radu

    2015-04-30

    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.

  12. Dilatonic wormholes: construction, operation, maintenance and collapse to black holes

    E-Print Network [OSTI]

    Sean A. Hayward; Sung-Won Kim; Hyunjoo Lee

    2001-10-18

    The CGHS two-dimensional dilaton gravity model is generalized to include a ghost Klein-Gordon field, i.e. with negative gravitational coupling. This exotic radiation supports the existence of static traversible wormhole solutions, analogous to Morris-Thorne wormholes. Since the field equations are explicitly integrable, concrete examples can be given of various dynamic wormhole processes, as follows. (i) Static wormholes are constructed by irradiating an initially static black hole with the ghost field. (ii) The operation of a wormhole to transport matter or radiation between the two universes is described, including the back-reaction on the wormhole, which is found to exhibit a type of neutral stability. (iii) It is shown how to maintain an operating wormhole in a static state, or return it to its original state, by turning up the ghost field. (iv) If the ghost field is turned off, either instantaneously or gradually, the wormhole collapses into a black hole.

  13. Global Inflow and Outflow Solutions (GIOS) around a Black Hole

    E-Print Network [OSTI]

    Sandip K. Chakrabarti

    1998-12-09

    Twenty five years have passed by since models of accretions and jets have separately emerged. Today, it is understood that these two objects are related to each other in a fundamental way. In a binary system, matter from an accretion disk enters into a black hole. A part of it is bounced back because of the centrifugal barrier, radiation pressure or magnetohydrodynamic effects, to form jets and bipolar outflows which carry away excess angular momentum. In the case of AGNs containing black holes, accretion disks form out of stellar winds and similar processes as above form cosmic radio jets. We present a general review of the study of the accretion disks and outflows in a coherent manner, especially emphasizing global inflow-outflow solutions (GIOS). We also present a few observational consequences of wind production from the accretion disks on spectral properties of the accretion disks.

  14. Satellite observations of thought experiments close to a black hole

    E-Print Network [OSTI]

    S. K. Chakrabarti

    2000-07-18

    Since black holes are `black', methods of their identification must necessarily be indirect. Due to very special boundary condition on the horizon, the advective flow behaves in a particular way, which includes formation of centrifugal pressure dominated boundary layer or CENBOL where much of the infall energy is released and outflows are generated. The observational aspects of black holes must depend on the steady and time-dependent properties of this boundary layer. Several observational results are written down in this review which seem to support the predictions of thought experiments based on this advective accretion/outflow model. In future, when gravitational waves are detected, some other predictions of this model could be tested as well.

  15. Are black holes in an ekpyrotic phase possible?

    E-Print Network [OSTI]

    J. C. S. Neves

    2015-09-10

    The ekpyrotic phase (a slow contraction cosmic phase before the current expansion phase) manages to solve the main problems of the standard cosmology by means of a scalar field interpreted as an isotropic cosmic fluid in the Friedmann equation. Moreover, this phase generates a nearly scale-invariant spectrum of perturbations in agreement with the latest data. Then, the ekpyrotic mechanism is a serious possibility to the inflationary model. In this work, we point out that it is impossible to generate a black hole with spherical symmetry supported by an isotropic fluid in this scenario. Using the approach of deforming metrics to obtain solutions with an isotropic energy-momentum tensor, we show that the stiff fluid, dominant in the ekpyrotic phase, does not support these black holes.

  16. Black hole lightning due to particle acceleration at subhorizon scales

    E-Print Network [OSTI]

    Aleksi?, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; González, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Oña; Mendez, C Delgado; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; López, R J García; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Godinovi?, N; Muñoz, A González; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Garcia, J Rodriguez; Rügamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzi?, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Zanin, R; Kadler, M; Schulz, R; Ros, E; Bach, U; Krauß, F; Wilms, J

    2014-01-01

    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry, but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here, we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC telescopes revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20\\% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

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

    E-Print Network [OSTI]

    Tom Banks; Willy Fischler

    2015-05-16

    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].

  18. Short distance signatures in Cosmology: Why not in Black Holes?

    E-Print Network [OSTI]

    Roberto Casadio; Laura Mersini

    2002-08-07

    Current theoretical investigations seem to indicate the possibility of observing signatures of short distance physics in the Cosmic Microwave Background spectrum. We try to gain a deeper understanding on why all information about this regime is lost in the case of Black Hole radiation but not necessarily so in a cosmological setting by using the moving mirror as a toy model for both backgrounds. The different responses of the Hawking and Cosmic Microwave Background spectra to short distance physics are derived in the appropriate limit when the moving mirror mimics a Black Hole background or an expanding universe. The different sensitivities to new physics, displayed by both backgrounds, are clarified through an averaging prescription that accounts for the intrinsic uncertainty in their quantum fluctuations. We then proceed to interpret the physical significance of our findings for time-dependent backgrounds in the light of nonlocal string theory.

  19. Positive specific heat of the quantum corrected dilaton black hole

    E-Print Network [OSTI]

    D. Grumiller; W. Kummer; D. V. Vassilevich

    2003-06-20

    Path integral quantization of dilaton gravity in two dimensions is applied to the CGHS model to the first nontrivial order in matter loops. Our approach is background independent as geometry is integrated out exactly. The result is an effective shift of the Killing norm: the apparent horizon becomes smaller. The Hawking temperature which is constant to leading order receives a quantum correction. As a consequence, the specific heat becomes positive and proportional to the square of the black hole mass.

  20. Quasi-black holes: general features and purely field configurations

    E-Print Network [OSTI]

    K. A. Bronnikov; O. B. Zaslavskii

    2015-04-27

    Objects that are on the threshold of forming the horizon but never collapse are called quasi-black holes (QBHs). We discuss the properties of the general spherically symmetric QBH metric without addressing its material source, including its limiting cases as the corresponding small parameter tends to zero. We then show that QBHs can exist among self-gravitating configurations of electromagnetic and dilatonic scalar fields without matter. These general results are illustrated by explicit examples of exact solutions.

  1. Black holes vs. naked singularities formation in collapsing Einstein's clusters

    E-Print Network [OSTI]

    S. Jhingan; G. Magli

    2000-01-10

    Non-static, spherically symmetric clusters of counter-rotating particles, of the type first introduced by Einstein, are analysed here. The initial data space can be parameterized in terms of three arbitrary functions, namely; initial density, velocity and angular momentum profiles. The final state of collapse, black hole or naked singularity, turns out to depend on the order of the first non-vanishing derivatives of such functions at the centre. The work extends recent results by Harada, Iguchi and Nakao.

  2. Repairs for damaged bolt holes in continuous fiber reinforced plastics 

    E-Print Network [OSTI]

    Copps, Kevin Daniel

    1992-01-01

    of fastened joints and to investigate previous techniques for the repair of continuous fiber reinforced plastics. LITERATURE REVIEW Characterizing Failure Modes There is very little agreement about what conditions constitute failure in composite joints... of possible methods for preventing and repairing fastener hole defects. Proper drilling technique The optimal drilling conditions for fiber reinforced parts are hard to control, and can differ depending on the structural application. The proper technique...

  3. Holographic superconductor developed in BTZ black hole background with backreactions

    E-Print Network [OSTI]

    Yunqi Liu; Qiyuan Pan; Bin Wang

    2011-06-22

    We develop a holographic superconductor in BTZ black hole background with backreactions. We investigate the influence of the backreaction on the condensation of the scalar hair and the dynamics of perturbation in the background spacetime. When the Breitenlohner-Freedman bound is approached, we argue that only one of two possible operators can reflect the real property of the condensation in the holographic superconductor. This argument is supported by the investigation in dynamics.

  4. Anti-de Sitter black holes in supergravity 

    E-Print Network [OSTI]

    Chong, Zhiwei

    2009-06-02

    -Generating Procedure . . . . . . . . . . . . . . . . 22 1. O(4,4) Symmetry of the Reduced D = 3 Theory . . . 23 2. O(1,1)4 Transformation of a Reduced Uncharged Solution . . . . . . . . . . . . . . . . . . . . . . . . . . 30 C. 4-Charge Rotating NUT Solution... of supersymmetric five-dimensional AdS black holes and that calculated from the counting of microstates in the D-brane models involving giant gravitons in the very recent paper [22]. In Chapter IV, we will present the details in constructing 12 these five...

  5. Power Law Corrections to BTZ Black Hole Entropy

    E-Print Network [OSTI]

    Dharm Veer Singh

    2014-11-14

    We study the quantum scalar field in the background of BTZ black hole and evaluate the entanglement entropy of the non-vacuum states. The entropy is proportional to the area of event horizon for the ground state, but the area law is violated in the case of non-vacuum states (first excited state and mixed states) and the corrections scale as power law.

  6. Jets from Tidal Disruptions of Stars by Black Holes

    E-Print Network [OSTI]

    Julian H. Krolik; Tsvi Piran

    2012-02-07

    Tidal disruption of main sequence stars by black holes has generally been thought to lead to a signal dominated by UV emission. If, however, the black hole spins rapidly and the poloidal magnetic field intensity on the black hole horizon is comparable to the inner accretion disk pressure, a powerful jet may form whose luminosity can easily exceed the thermal UV luminosity. When the jet beam points at Earth, its non-thermal luminosity can dominate the emitted spectrum. The thermal and non-thermal components decay differently with time. In particular, the thermal emission should remain roughly constant for a significant time after the period of maximum accretion, beginning to diminish only after a delay, whereas after the peak accretion rate, the non-thermal jet emission decays, but then reaches a plateau. Both transitions are tied to a characteristic timescale $t_{\\rm Edd}$ at which the accretion rate falls below Eddington. Making use of this timescale in a new parameter-inference formalism for tidal disruption events with significant emission from a jet, we analyze the recent flare source Swift J2058. It is consistent with an event in which a main sequence solar-type staris disrupted by a black hole of mass $\\sim 4 \\times 10^7 M_{\\odot}$. The beginning of the flat phase in the non-thermal emission from this source can possibly be seen in the late-time lightcurve. Optical photometry over the first $\\simeq 40$ d of this flare is also consistent with this picture, but is only weakly constraining because the bolometric correction is very uncertain. We suggest that future searches for main sequence tidal disruptions use methods sensitive to jet radiation as well as to thermal UV radiation.

  7. A mathematical simulation of horizontal drain-hole performance 

    E-Print Network [OSTI]

    Cheng, Thomas Ru-Kang

    1984-01-01

    Science and Technology, Kee-Lung, Taiwan, Republic of China Chairman of Advisory Comnittee: Dr. Ching H. Wu The application of horizontal drain-hole in petroleum industry represents one of the new developments in oil recovery techniques. Many... production condition was simulated. The validity of the computational algorithm employed in the simulator was ascertained using the results obtained from a general purpose black oil simulator, BOSS-AIM. The verification runs were made under a semi...

  8. Optical properties of black hole in the presence of plasma: shadow

    E-Print Network [OSTI]

    Farruh Atamurotov; Bobomurat Ahmedov; Ahmadjon Abdujabbarov

    2015-08-28

    We have studied photon motion around axially symmetric rotating Kerr black hole in the presence of plasma with radial power-law density. It is shown that in the presence of plasma the observed shape and size of shadow changes depending on i) plasma parameters, ii) black hole spin and iii) inclination angle between observer plane and axis of rotation of black hole. In order to extract pure effect of plasma influence on black hole image the particular case of the Schwarzschild black hole has also been investigated and it has been shown that i) the photon sphere around the spherical symmetric black hole is left unchanged under the plasma influence, ii) however the Schwarzschild black hole shadow size in plasma is reduced due to the refraction of the electromagnetic radiation in plasma environment of black hole. The study of the energy emission from the black hole in plasma shows that in the presence of plasma the maximal energy emission rate from the black hole decreases.

  9. Global solutions for higher-dimensional stretched small black holes

    SciTech Connect (OSTI)

    Chen, C.-M.; Gal'tsov, Dmitri V.; Ohta, Nobuyoshi; Orlov, Dmitry G.

    2010-01-15

    Small black holes in heterotic string theory have a vanishing horizon area at the supergravity level, but the horizon is stretched to the finite radius AdS{sub 2}xS{sup D-2} geometry once higher curvature corrections are turned on. This has been demonstrated to give good agreement with microscopic entropy counting. Previous considerations, however, were based on the classical local solutions valid only in the vicinity of the event horizon. Here we address the question of global existence of extremal black holes in the D-dimensional Einstein-Maxwell-Dilaton theory with the Gauss-Bonnet term introducing a variable dilaton coupling a as a parameter. We show that asymptotically flat black holes exist only in a bounded region of the dilaton couplings 0=}5 (but not for D=4) the allowed range of a includes the heterotic string values. For a>a{sub cr} numerical solutions meet weak naked singularities at finite radii r=r{sub cusp} (spherical cusps), where the scalar curvature diverges as |r-r{sub cusp}|{sup -1/2}. For D{>=}7 cusps are met in pairs, so that solutions can be formally extended to asymptotically flat infinity choosing a suitable integration variable. We show, however, that radial geodesics cannot be continued through the cusp singularities, so such a continuation is unphysical.

  10. Can black holes and naked singularities be detected in accelerators?

    E-Print Network [OSTI]

    R. Casadio; B. Harms

    2002-01-07

    We study the conditions for the existence of black holes that can be produced in colliders at TeV-scale if the space-time is higher dimensional. On employing the microcanonical picture, we find that their life-times strongly depend on the details of the model. If the extra dimensions are compact (ADD model), microcanonical deviations from thermality are in general significant near the fundamental TeV mass and tiny black holes decay more slowly than predicted by the canonical expression, but still fast enough to disappear almost instantaneously. However, with one warped extra dimension (RS model), microcanonical corrections are much larger and tiny black holes appear to be (meta)stable. Further, if the total charge is not zero, we argue that naked singularities do not occur provided the electromagnetic field is strictly confined on an infinitely thin brane. However, they might be produced in colliders if the effective thickness of the brane is of the order of the fundamental length scale (~1/TeV).

  11. Zero energy rotating accretion flows near a black hole

    E-Print Network [OSTI]

    Ryu, D; Molteni, D; Ryu, Dongsu; Chakrabarti, Sandip K; Molteni, Diego

    1996-01-01

    We characterize the nature of thin, axisymmetric, inviscid, accretion flows of cold adiabatic gas with zero specific energy in the vicinity of a black hole by the specific angular momentum. Using two-dimensional hydrodynamic simulations in cylindrical geometry, we present various regimes in which the accretion flows behave distinctly differently. When the flow has a small angular momentum (\\lambda\\lsim\\lambda_b), most of the material is accreted into the black hole forming a quasi-spherical flow or a simple disk-like structure around it. When the flow has a large angular momentum (typically, larger than the marginally bound value, \\lambda\\gsim\\lambda_{mb}), almost no accretion into the black hole occurs. Instead, the flow produces a stable standing shock with one or more vortices behind it and is deflected away at the shock as a conical outgoing wind of higher entropy. If the flow has an angular momentum somewhat smaller than \\lambda_{mb} (\\lambda_{u}\\lsim\\lambda\\lsim\\lambda_{mb}), a fraction (typically, 5-10...

  12. Functional determinants, index theorems, and exact quantum black hole entropy

    E-Print Network [OSTI]

    Murthy, Sameer

    2015-01-01

    The exact quantum entropy of BPS black holes can be evaluated using localization in supergravity. An important ingredient in this program, that has been lacking so far, is the one-loop effect arising from the quadratic fluctuations of the exact deformation (the $Q\\mathcal{V}$ operator). We compute the fluctuation determinant for vector multiplets and hyper multiplets around $Q$-invariant off-shell configurations in four-dimensional $\\mathcal{N}=2$ supergravity with $AdS_{2} \\times S^{2}$ boundary conditions, using the Atiyah-Bott fixed-point index theorem and a subsequent zeta function regularization. Our results extend the large-charge on-shell entropy computations in the literature to a regime of finite charges. Based on our results, we present an exact formula for the quantum entropy of BPS black holes in $\\mathcal{N}=2$ supergravity. We explain cancellations concerning $\\frac18$-BPS black holes in $\\mathcal{N}=8$ supergravity that were observed previously. We also make comments about the interpretation of...

  13. Functional determinants, index theorems, and exact quantum black hole entropy

    E-Print Network [OSTI]

    Sameer Murthy; Valentin Reys

    2015-08-10

    The exact quantum entropy of BPS black holes can be evaluated using localization in supergravity. An important ingredient in this program, that has been lacking so far, is the one-loop effect arising from the quadratic fluctuations of the exact deformation (the $Q\\mathcal{V}$ operator). We compute the fluctuation determinant for vector multiplets and hyper multiplets around $Q$-invariant off-shell configurations in four-dimensional $\\mathcal{N}=2$ supergravity with $AdS_{2} \\times S^{2}$ boundary conditions, using the Atiyah-Bott fixed-point index theorem and a subsequent zeta function regularization. Our results extend the large-charge on-shell entropy computations in the literature to a regime of finite charges. Based on our results, we present an exact formula for the quantum entropy of BPS black holes in $\\mathcal{N}=2$ supergravity. We explain cancellations concerning $\\frac18$-BPS black holes in $\\mathcal{N}=8$ supergravity that were observed in arXiv:1111.1161. We also make comments about the interpretation of a logarithmic term in the topological string partition function in the low energy supergravity theory.

  14. Supersymmetric black holes and attractors in gauged supergravity with hypermultiplets

    E-Print Network [OSTI]

    Samuele Chimento; Dietmar Klemm; Nicolò Petri

    2015-04-13

    We consider four-dimensional $N=2$ supergravity coupled to vector- and hypermultiplets, where abelian isometries of the quaternionic K\\"ahler hypermultiplet scalar manifold are gauged. Using the recipe given by Meessen and Ort\\'{\\i}n in arXiv:1204.0493, we analytically construct a supersymmetric black hole solution for the case of just one vector multiplet with prepotential ${\\cal F}=-i\\chi^0\\chi^1$, and the universal hypermultiplet. This solution has a running dilaton, and it interpolates between $\\text{AdS}_2\\times\\text{H}^2$ at the horizon and a hyperscaling-violating type geometry at infinity, conformal to $\\text{AdS}_2\\times\\text{H}^2$. It carries two magnetic charges that are completely fixed in terms of the parameters that appear in the Killing vector used for the gauging. In the second part of the paper, we extend the work of Bellucci et al. on black hole attractors in gauged supergravity to the case where also hypermultiplets are present. The attractors are shown to be governed by an effective potential $V_{\\text{eff}}$, which is extremized on the horizon by all the scalar fields of the theory. Moreover, the entropy is given by the critical value of $V_{\\text{eff}}$. In the limit of vanishing scalar potential, $V_{\\text{eff}}$ reduces (up to a prefactor) to the usual black hole potential.

  15. Thermodynamics of higher spin black holes in 3D

    E-Print Network [OSTI]

    Justin R. David; Michael Ferlaino; S. Prem Kumar

    2012-10-01

    We examine the thermodynamic properties of recently constructed black hole solutions in SL(3,R) x SL(3,R) Chern-Simons theory in the presence of a chemical potential for spin-3 charge, which acts as an irrelevant deformation of the dual CFT with W_3 x W_3 symmetry. The smoothness or holonomy conditions admit four branches of solutions describing a flow between two AdS_3 backgrounds corresponding to two different CFTs. The dominant branch at low temperatures, connected to the BTZ black hole, merges smoothly with a thermodynamically unstable branch and disappears at higher temperatures. We confirm that the UV region of the flow satisfies the Ward identities of a CFT with W_3^(2) x W_3^(2) symmetry deformed by a spin-3/2 current. This allows to identify the precise map between UV and IR thermodynamic variables. We find that the high temperature regime is dominated by a black hole branch whose thermodynamics can only be consistently inferred with reference to this W_3^(2) x W_3^(2) CFT.

  16. Particle-hole duality, integrability, and Russian doll BCS model

    E-Print Network [OSTI]

    L. V. Bork; W. V. Pogosov

    2015-05-04

    We address a generalized Richardson model (Russian doll BCS model), which is characterized by the breaking of time-reversal symmetry. This model is known to be exactly solvable and integrable. We point out that the Russian doll BCS model, on the level of Hamiltonian, is also particle-hole symmetric. This implies that the same state can be expressed both in the particle and hole representations with two different sets of Bethe roots. We then derive exact relations between Bethe roots in the two representations, which can hardly be obtained staying on the level of Bethe equations. In a quasi-classical limit, similar identities for usual Richardson model, known from literature, are recovered from our results. We also show that these relations for Richardson roots take a remarkably simple form at half-filling and for a symmetric with respect to the middle of the interaction band distribution of one-body energy levels, since, in this special case, the rapidities in the particle and hole representations up to the translation satisfy the same system of equations.

  17. Strong Gravitational Lensing in a Brane-World Black Hole

    E-Print Network [OSTI]

    GuoPing Li; Biao Cao; Zhongwen Feng; Xiaotao Zu

    2015-06-28

    Adopting the strong field limit approach, we investigated the strong gravitational lensing in a Brane-World black hole, which means that the strong field limit coefficients and the deflection angle in this gravitational field are obtained. With this result, it can be said with certainly that the strong gravitational lensing is related to the metric of gravitational fields closely, the cosmology parameter {\\alpha} and the dark matter parameter \\b{eta} come from the Brane-World black hole exerts a great influence on it. Comparing with the Schwarzschild-AdS spacetime and the Schwarzschild-XCMD spacetime, the parameters {\\alpha}, \\b{eta} of black holes have the similar effects on the gravitational lensing. In some way, we infer that the real gravitational fields in our universe can be described by this metric, so the results of the strong gravitational lensing in this spacetime will be more reasonable for us to observe. Finally, it has to be noticed that the influence which the parameters {\\alpha}, \\b{eta} exerted on the main observable quantities of this gravitational field is discussed.

  18. Formation and early evolution of massive black holes

    E-Print Network [OSTI]

    Madau, P

    2007-01-01

    The astrophysical processes that led to the formation of the first seed black holes and to their growth into the supermassive variety that powers bright quasars at redshift 6 are poorly understood. In standard LCDM hierarchical cosmologies, the earliest massive holes (MBHs) likely formed at redshift z~15 at the centers of low-mass (M>5e5 solar masses) dark matter ``minihalos'', and produced hard radiation by accretion. FUV/X-ray photons from such ``miniquasars'' may have permeated the universe more uniformly than EUV radiation, reduced gas clumping, and changed the chemistry of primordial gas. The role of accreting seed black holes in determining the thermal and ionization state of the intergalactic medium depends on the amount of cold and dense gas that forms and gets retained in protogalaxies after the formation of the first stars. The highest resolution N-body simulation to date of Galactic substructure shows that subhalos below the atomic cooling mass were very inefficient at forming stars.

  19. Formation and early evolution of massive black holes

    E-Print Network [OSTI]

    Piero Madau

    2007-01-12

    The astrophysical processes that led to the formation of the first seed black holes and to their growth into the supermassive variety that powers bright quasars at redshift 6 are poorly understood. In standard LCDM hierarchical cosmologies, the earliest massive holes (MBHs) likely formed at redshift z~15 at the centers of low-mass (M>5e5 solar masses) dark matter ``minihalos'', and produced hard radiation by accretion. FUV/X-ray photons from such ``miniquasars'' may have permeated the universe more uniformly than EUV radiation, reduced gas clumping, and changed the chemistry of primordial gas. The role of accreting seed black holes in determining the thermal and ionization state of the intergalactic medium depends on the amount of cold and dense gas that forms and gets retained in protogalaxies after the formation of the first stars. The highest resolution N-body simulation to date of Galactic substructure shows that subhalos below the atomic cooling mass were very inefficient at forming stars.

  20. Effective Polymer Dynamics of D-Dimensional Black Hole Interiors

    E-Print Network [OSTI]

    A. Peltola; G. Kunstatter

    2009-09-01

    We consider two different effective polymerization schemes applied to D-dimensional, spherically symmetric black hole interiors. It is shown that polymerization of the generalized area variable alone leads to a complete, regular, single-horizon spacetime in which the classical singularity is replaced by a bounce. The bounce radius is independent of rescalings of the homogeneous internal coordinate, but does depend on the arbitrary fiducial cell size. The model is therefore necessarily incomplete. It nonetheless has many interesting features: After the bounce, the interior region asymptotes to an infinitely expanding Kantowski-Sachs spacetime. If the solution is analytically continued across the horizon, the black hole exterior exhibits asymptotically vanishing quantum-corrections due to the polymerization. In all spacetime dimensions except four, the fall-off is too slow to guarantee invariance under Poincare transformations in the exterior asymptotic region. Hence the four-dimensional solution stands out as the only example which satisfies the criteria for asymptotic flatness. In this case it is possible to calculate the quantum-corrected temperature and entropy. We also show that polymerization of both phase space variables, the area and the conformal mode of the metric, generically leads to a multiple horizon solution which is reminiscent of polymerized mini-superspace models of spherically symmetric black holes in Loop Quantum Gravity.