Axion inflation in type II string theory
Grimm, Thomas W. [Physikalisches Institut der Universitaet Bonn, Nussallee 12, 53115 Bonn (Germany) and Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)
2008-06-15T23:59:59.000Z
Inflationary models driven by a large number of axion fields are discussed in the context of type IIB compactifications with N=1 supersymmetry. The inflatons arise as the scalar modes of the R-R two-forms evaluated on vanishing two-cycles in the compact geometry. The vanishing cycles are resolved by small two-volumes or NS-NS B fields which sit together with the inflatons in the same supermultiplets. String world sheets wrapping the vanishing cycles correct the metric of the R-R inflatons. They can help to generate kinetic terms close to the Planck scale and a mass hierarchy between the axions and their nonaxionic partners during inflation. At small string coupling, D-brane corrections are subleading in the metric of the R-R inflatons. However, an axion potential can be generated by D1 instantons or gaugino condensates on D5-branes. Models with a sufficiently large number of axions admit regions of chaotic inflation which can stretch over the whole axion field range for potentials from gaugino condensates. These models could allow for a possibly detectable amount of gravitational waves with tensor to scalar ratio as high as r<0.14.
Closed tachyon solitons in type II string theory
Ińaki García-Etxebarria; Miguel Montero; Angel M. Uranga
2015-05-20T23:59:59.000Z
Type II theories can be described as the endpoint of closed string tachyon condensation in certain orbifolds of supercritical type 0 theories. In this paper, we study solitons of this closed string tachyon and analyze the nature of the resulting defects in critical type II theories. The solitons are classified by the real K-theory groups KO of bundles associated to pairs of supercritical dimensions. For real codimension 4 and 8, corresponding to $KO({\\bf S}^4)={\\bf Z}$ and $KO({\\bf S}^8)={\\bf Z}$, the defects correspond to a gravitational instanton and a fundamental string, respectively. We apply these ideas to reinterpret the worldsheet GLSM, regarded as a supercritical theory on the ambient toric space with closed tachyon condensation onto the CY hypersurface, and use it to describe charged solitons under discrete isometries. We also suggest the possible applications of supercritical strings to the physical interpretation of the matrix factorization description of F-theory on singular spaces.
Double field theory of type II strings
Hohm, Olaf
We use double field theory to give a unified description of the low energy limits of type IIA and type IIB superstrings. The Ramond-Ramond potentials fit into spinor representations of the duality group O(D, D) and ...
Some Properties of Type I' String Theory
John H. Schwarz
1999-07-26T23:59:59.000Z
The T-dual formulation of Type I superstring theory, sometimes called Type I' theory, has a number of interesting features. Here we review some of them including the role of D0-branes and D8-branes in controlling possible gauge symmetry enhancement.
Phenomenology of heterotic and type II orientifold string models
Mayes, Van Eric
2009-05-15T23:59:59.000Z
. SupersymmetryConditionsintheOpenString Sector . . . . . . . . . . . . . . . . . . . . . . . . 73 5. RR Tadpole Cancellation and K-theory Constraints . 73 6. The Green-Schwarz Mechanism for Flipped SU(5) GUT Construction . . . . . . . . . . . . . . . . . . . . 75...)?SU(2)L?SU(2)R?[U(2)4? U(1)3]. The ?0d representations indicate light, non-chiral matter which is present between pairs of fractional branes which wrap homologically identical bulk cycles, but difier in their twisted cycles. 98 XVI Stacks, wrapping...
AN ARSCL-BASED CLOUD TYPE CLIMATOLOGY FROM RETRIEVALS AND IT'S USE IN MODEL EVALUATION STUDIES
AN ARSCL-BASED CLOUD TYPE CLIMATOLOGY FROM RETRIEVALS AND IT'S USE IN MODEL EVALUATION STUDIES Laboratory P.O. Box, Upton, NY www.bnl.gov ABSTRACT A climatology of cloud types is developed using long in tandem with satellite observations for model cloud layering and property evaluation. Therefore, satellite
Comments on the Nekrasov-type formula for E-string theory
Ishii, Takenori
2015-01-01T23:59:59.000Z
We generalise our previous result\\cite{13} to cases with three and four Wilson lines. We show that the Nekrasov-type formula for E-string theory is valid for those cases and the Seiberg-Witten curves are reproduced from the formula. In addition, we show the dependence of the Seiberg-Witten curve on the Wilson lines.
Topology of the hypermultiplet moduli space in type II/CY string vacua
Alexandrov, Sergei [Laboratoire de Physique Theorique, Astroparticules, CNRS UMR 5207, Universite Montpellier II, 34095 Montpellier Cedex 05 (France); Persson, Daniel [Institut fuer Theoretische Physik, ETH Zuerich, CH-8093 Zuerich (Switzerland); Pioline, Boris [Laboratoire de Physique Theorique et Hautes Energies, CNRS UMR 7589, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 05 (France)
2011-01-15T23:59:59.000Z
By analyzing qualitative aspects of NS5-brane instanton corrections, we determine the topology of the hypermultiplet moduli space M{sub H} in Calabi-Yau compactifications of type II string theories at fixed value of the dilaton and of the Calabi-Yau metric. Specifically, we show that for fivebrane instanton couplings to be well-defined, translations along the intermediate Jacobian must induce nontrivial shifts of the Neveu-Schwarz axion which had thus far been overlooked. As a result, the Neveu-Schwarz axion parametrizes the fiber of a circle bundle, isomorphic to the one in which the fivebrane partition function is valued. In a companion paper, we go beyond the present analysis and take steps towards a quantitative description of fivebrane instanton corrections, using a combination of mirror symmetry, S-duality, topological string theory and twistor techniques.
On zero-point energy, stability and Hagedorn behavior of Type IIB strings on pp-waves
F. Bigazzi; A. L. Cotrone
2003-09-09T23:59:59.000Z
Type IIB strings on many pp-wave backgrounds, supported either by 5-form or 3-form fluxes, have negative light-cone zero-point energy. This raises the question of their stability and poses possible problems in the definition of their thermodynamic properties. After having pointed out the correct way of calculating the zero-point energy, an issue not fully discussed in literature, we show that these Type IIB strings are classically stable and have well defined thermal properties, exhibiting a Hagedorn behavior.
Positivity of Lyapunov exponents for Anderson-type models on two coupled strings
Hakim Boumaza; Günter Stolz
2006-11-01T23:59:59.000Z
We study two models of Anderson-type random operators on two deterministically coupled continuous strings. Each model is associated with independent, identically distributed four-by-four symplectic transfer matrices, which describe the asymptotics of solutions. In each case we use a criterion by Gol'dsheid and Margulis (i.e. Zariski denseness of the group generated by the transfer matrices in the group of symplectic matrices) to prove positivity of both leading Lyapunov exponents for most energies. In each case this implies almost sure absence of absolutely continuous spectrum (at all energies in the first model and for sufficiently large energies in the second model). The methods used allow for singularly distributed random parameters, including Bernoulli distributions.
STRUCTURED TEXT RETRIEVAL MODELS Djoerd Hiemstra
Hiemstra, Djoerd
and manipulating content and hierarchical structure such as the parsed strings model [10], PAT expressions [15STRUCTURED TEXT RETRIEVAL MODELS Djoerd Hiemstra University of Twente http DEFINITION Structured text retrieval models provide a formal definition or mathematical framework
Engineering of Quantum Hall Effect from Type IIA String Theory on The K3 Surface
Adil Belhaj; Antonio Segui
2010-07-02T23:59:59.000Z
Using D-brane configurations on the K3 surface, we give six dimensional type IIA stringy realizations of the Quantum Hall Effect (QHE) in 1+2 dimensions. Based on the vertical and horizontal lines of the K3 Hodge diamond, we engineer two different stringy realizations. The vertical line presents a realization in terms of D2 and D6-branes wrapping the K3 surface. The horizontal one is associated with hierarchical stringy descriptions obtained from a quiver gauge theory living on a stack of D4-branes wrapping intersecting 2-spheres embedded in the K3 surface with deformed singularities. These geometries are classified by three kinds of the Kac-Moody algebras: ordinary, i.e finite dimensional, affine and indefinite. We find that no stringy QHE in 1+2 dimensions can occur in the quiver gauge theory living on intersecting 2-spheres arranged as affine Dynkin diagrams. Stringy realizations of QHE can be done only for the finite and indefinite geometries. In particular, the finite Lie algebras give models with fractional filling fractions, while the indefinite ones classify models with negative filling fractions which can be associated with the physics of holes in the graphene.
Combined Retrieval, Microphysical Retrievals and Heating Rates
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Feng, Zhe
Microphysical retrievals and heating rates from the AMIE/Gan deployment using the PNNL Combined Retrieval.
Finite Temperature Gases of Fermionic Strings
Shyamoli Chaudhuri
2005-09-12T23:59:59.000Z
We show that in the absence of a Ramond-Ramond sector both the type IIA and type IIB free string gases have a thermal instability due to low temperature tachyon modes. The gas of free IIA strings undergoes a thermal duality transition into a gas of free IIB strings at the self-dual temperature. The free heterotic string gas is a tachyon-free ensemble with gauge symmetry SO(16)$\\times$SO(16) in the presence of a timelike Wilson line background. It exhibits a holographic duality relation undergoing a self-dual phase transition with positive free energy and positive specific heat. The type IB open and closed string ensemble is related by thermal duality to the type I' string ensemble. We identify the order parameter for the Kosterlitz-Thouless phase transition from a low temperature gas of short open strings to a high temperature long string phase at or below T_C. Note Added (Sep 2005).
Bachas, C.
1986-03-01T23:59:59.000Z
This is an elementary introduction to the classical and quantum mechanics of a single bosonic string, and to some aspects of its supersymmetric and heterotic extensions. 22 refs.
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-02-05T23:59:59.000Z
We uncover a remarkable role that an infinite hierarchy of non-linear differential equations plays in organizing and connecting certain {hat c}<1 string theories non-perturbatively. We are able to embed the type 0A and 0B (A,A) minimal string theories into this single framework. The string theories arise as special limits of a rich system of equations underpinned by an integrable system known as the dispersive water wave hierarchy. We observe that there are several other string-like limits of the system, and conjecture that some of them are type IIA and IIB (A,D) minimal string backgrounds. We explain how these and several string-like special points arise and are connected. In some cases, the framework endows the theories with a non-perturbative definition for the first time. Notably, we discover that the Painleve IV equation plays a key role in organizing the string theory physics, joining its siblings, Painleve I and II, whose roles have previously been identified in this minimal string context.
M-strings, Elliptic Genera and N=4 String Amplitudes
Stefan Hohenegger; Amer Iqbal
2014-03-11T23:59:59.000Z
We study mass-deformed N=2 gauge theories from various points of view. Their partition functions can be computed via three dual approaches: firstly, (p,q)-brane webs in type II string theory using Nekrasov's instanton calculus, secondly, the (refined) topological string using the topological vertex formalism and thirdly, M theory via the elliptic genus of certain M-strings configurations. We argue for a large class of theories that these approaches yield the same gauge theory partition function which we study in detail. To make their modular properties more tangible, we consider a fourth approach by connecting the partition function to the equivariant elliptic genus of R^4 through a (singular) theta-transform. This form appears naturally as a specific class of one-loop scattering amplitudes in type II string theory on T^2, which we calculate explicitly.
String bit models for superstring
Bergman, O.; Thorn, C.B.
1995-12-31T23:59:59.000Z
The authors extend the model of string as a polymer of string bits to the case of superstring. They mainly concentrate on type II-B superstring, with some discussion of the obstacles presented by not II-B superstring, together with possible strategies for surmounting them. As with previous work on bosonic string work within the light-cone gauge. The bit model possesses a good deal less symmetry than the continuous string theory. For one thing, the bit model is formulated as a Galilei invariant theory in (D {minus} 2) + 1 dimensional space-time. This means that Poincare invariance is reduced to the Galilei subgroup in D {minus} 2 space dimensions. Naturally the supersymmetry present in the bit model is likewise dramatically reduced. Continuous string can arise in the bit models with the formation of infinitely long polymers of string bits. Under the right circumstances (at the critical dimension) these polymers can behave as string moving in D dimensional space-time enjoying the full N = 2 Poincare supersymmetric dynamics of type II-B superstring.
Low energy 2+1 string gravity; black hole solutions
A. A. Garcia Diaz; G. Gutierrez Cano
2014-12-17T23:59:59.000Z
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.
G. L. Alberghi
2010-02-19T23:59:59.000Z
We describe a possible realization of the spontaneous baryogenesis mechanism in the context of extra-dimensional string cosmology and specifically in the string gas scenario.
Sergio Giardino
2013-05-21T23:59:59.000Z
In this article the quantum fluctuation of a rigid and static string is reported to be identical to a free quantum particle. Solutions similar to this static string have already been found in the semi-classical quantizaton of pulsating strings, and our results show that the semi-classical quantization of pulsating strings is, in some cases, a perturbation of static strings. We also interpret the energy of the static string as a lower bound for the pulsating string and speculate about a description of quantum mechanics in terms of semi-classical string theory.
Daniel Schubring; Vitaly Vanchurin
2013-06-02T23:59:59.000Z
We consider conserved currents in an interacting network of one-dimensional objects (or strings). Singular currents localized on a single string are considered in general, and a formal procedure for coarse-graining over many strings is developed. This procedure is applied to strings described by the Nambu-Goto action such as cosmic strings. In addition to conserved currents corresponding to the energy-momentum tensor, we consider an antisymmetric tensor of conserved currents related to the string tangent vector. Under the assumption of local equilibrium we derive a complete set of hydrodynamic equations for strings.
Washington Taylor
2006-06-28T23:59:59.000Z
This elementary introduction to string field theory highlights the features and the limitations of this approach to quantum gravity as it is currently understood. String field theory is a formulation of string theory as a field theory in space-time with an infinite number of massive fields. Although existing constructions of string field theory require expanding around a fixed choice of space-time background, the theory is in principle background-independent, in the sense that different backgrounds can be realized as different field configurations in the theory. String field theory is the only string formalism developed so far which, in principle, has the potential to systematically address questions involving multiple asymptotically distinct string backgrounds. Thus, although it is not yet well defined as a quantum theory, string field theory may eventually be helpful for understanding questions related to cosmology in string theory.
Cosmological String Backgrounds from Gauged WZW Models
C. Kounnas; D. Luest
1992-05-18T23:59:59.000Z
We discuss the four-dimensional target-space interpretation of bosonic strings based on gauged WZW models, in particular of those based on the non-compact coset space $SL(2,{\\bf R})\\times SO(1,1)^2 /SO(1,1)$. We show that these theories lead, apart from the recently broadly discussed black-hole type of backgrounds, to cosmological string backgrounds, such as an expanding Universe. Which of the two cases is realized depends on the sign of the level of the corresponding Kac-Moody algebra. We discuss various aspects of these new cosmological string backgrounds.
Jorgensen, D.K.; Kuhns, D.J.; Wiersholm, O.; Miller, T.A.
1993-03-02T23:59:59.000Z
The drill string enclosure consists of six component parts, including; a top bracket, an upper acrylic cylinder, an acrylic drill casing guide, a lower acrylic cylinder, a bottom bracket, and three flexible ducts. The upper acrylic cylinder is optional based upon the drill string length. The drill string enclosure allows for an efficient drill and sight operation at a hazardous waste site.
Neil. D. Lambert; David Tong
1999-07-13T23:59:59.000Z
We study two-dimensional SQED viewed as the world-volume theory of a D-string in the presence of D5-branes with non-zero background fields that induce attractive forces between the branes. In various approximations, the low-energy dynamics is given by a hyperKahler, or hyperKahler with torsion, massive sigma-model. We demonstrate the existence of kink solutions corresponding to the string interpolating between different D5-branes. Bound states of the D-string with fundamental strings are identified with Q-kinks which, in turn, are identified with dyonic instanton strings on the D5-brane world-volume.
String Universality in Six Dimensions
Vijay Kumar; Washington Taylor
2009-10-10T23:59:59.000Z
In six dimensions, cancellation of gauge, gravitational, and mixed anomalies strongly constrains the set of quantum field theories which can be coupled consistently to gravity. We show that for some classes of six-dimensional supersymmetric gauge theories coupled to gravity, the anomaly cancellation conditions are equivalent to tadpole cancellation and other constraints on the matter content of heterotic/type I compactifications on K3. In these cases, all consistent 6D supergravity theories have a realization in string theory. We find one example which may arise from a novel string compactification, and we identify a new infinite family of models satisfying anomaly factorization. We find, however, that this infinite family of models, as well as other infinite families of models previously identified by Schwarz are pathological. We suggest that it may be feasible to demonstrate that there is a string theoretic realization of all consistent six-dimensional supergravity theories which have Lagrangian descriptions with arbitrary gauge and matter content. We attempt to frame this hypothesis of string universality as a concrete conjecture.
String Amplitudes from Moyal String Field Theory
I. Bars; I. Kishimoto; Y. Matsuo
2002-12-29T23:59:59.000Z
We illustrate a basic framework for analytic computations of Feynman graphs using the Moyal star formulation of string field theory. We present efficient methods of computation based on (a) the monoid algebra in noncommutative space and (b) the conventional Feynman rules in Fourier space. The methods apply equally well to perturbative string states or nonperturbative string states involving D-branes. The ghost sector is formulated using Moyal products with fermionic (b,c) ghosts. We also provide a short account on how the purely cubic theory and/or VSFT proposals may receive some clarification of their midpoint structures in our regularized framework.
Non-perturbative String Theory from Water Waves
Ramakrishnan Iyer; Clifford V. Johnson; Jeffrey S. Pennington
2010-11-29T23:59:59.000Z
We use a combination of a 't Hooft limit and numerical methods to find non-perturbative solutions of exactly solvable string theories, showing that perturbative solutions in different asymptotic regimes are connected by smooth interpolating functions. Our earlier perturbative work showed that a large class of minimal string theories arise as special limits of a Painleve IV hierarchy of string equations that can be derived by a similarity reduction of the dispersive water wave hierarchy of differential equations. The hierarchy of string equations contains new perturbative solutions, some of which were conjectured to be the type IIA and IIB string theories coupled to (4,4k-2) superconformal minimal models of type (A,D). Our present paper shows that these new theories have smooth non-perturbative extensions. We also find evidence for putative new string theories that were not apparent in the perturbative analysis.
Effect of cosmic string on spin dynamics
Debashree Chowdhury; B. Basu
2014-11-07T23:59:59.000Z
In the present paper, we have investigated the role of cosmic string on spin current and Hall electric field. Due to the background cosmic string, the modified electric field of the system generates renormalized spin orbit coupling, which induces a modified non-Abelian gauge field. The defect causes a change in the AB and AC phases appearing due to the modified electromagnetic field. In addition, for a time varying electric field we perform explicit analytic calculations to derive the exact form of spin electric field and spin current, which is defect parameter dependent and of oscillating type. Furthermore, in an asymmetric crystal within the Drude model approach we investigate the dependence of the cosmic string parameters on cosmic string induced Hall electric field.
Roberto Iengo; Jorge G. Russo
2006-02-20T23:59:59.000Z
We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of time -- the ``squashing ellipse''. This string interpolates between the folded string with maximum angular momentum and the pulsating circular string. We explicitly compute the quantum decay rate for the corresponding quantum state, and verify the basic rules that we propose. Finally, we give a more general (4-parameter) family of closed string solutions representing rotating and pulsating elliptical strings.
Broader source: Energy.gov [DOE]
This report is an independent product of the Type A Accident Investigation Board appointed by Tara O’Toole, M.D., M.P.H., Assistant Secretary for Environment, Safety and Health (EH-1).
John H. Schwarz
1995-03-20T23:59:59.000Z
A brief review of the status of duality symmetries in string theory is presented. The evidence is accumulating rapidly that an enormous group of duality symmetries, including perturbative T dualities and non-perturbative S-dualities, underlies string theory. It is my hope that an understanding of these symmetries will suggest the right way to formulate non-perturbative string theory. Whether or not this hope is realized, it has already been demonstrated that this line of inquiry leads to powerful new tools for understanding gauge theories and new evidence for the uniqueness of string theory, as well as deep mathematical results.
Eisenstein Series in String Theory
N. A. Obers; B. Pioline
2000-03-01T23:59:59.000Z
We discuss the relevance of Eisenstein series for representing certain G(Z)-invariant string theory amplitudes which receive corrections from BPS states only. The Eisenstein series are constructed using G(Z)-invariant mass formulae and are manifestly invariant modular functions on the symmetric space K\\G(R) of non-compact type, with K the maximal compact subgroup of G(R). In particular, we show how Eisenstein series of the T-duality group SO(d,d,Z) can be used to represent one- and g-loop amplitudes in compactified string theory. We also obtain their non-perturbative extensions in terms of the Eisenstein series of the U-duality group E_{d+1(d+1)}(Z).
Weigel, H. [Physics Department, Stellenbosch University, Matieland 7602 (South Africa); Quandt, M. [Institute for Theoretical Physics, Tuebingen University, D-72076 Tuebingen (Germany); Graham, N. [Department of Physics, Middlebury College , Middlebury, Vermont 05753 (United States)
2011-03-11T23:59:59.000Z
We study the quantum stabilization of a cosmic string by a heavy fermion doublet in a reduced version of the standard model. We show that charged strings, obtained by populating fermionic bound state levels, become stable if the electroweak bosons are coupled to a fermion that is less than twice as heavy as the top quark. This result suggests that extraordinarily large fermion masses or unrealistic couplings are not required to bind a cosmic string in the standard model. Numerically we find the most favorable string profile to be a simple trough in the Higgs vacuum expectation value of radius {approx_equal}10{sup -18} m. The vacuum remains stable in our model, because neutral strings are not energetically favored.
Grassmannian and string theory
Albert Schwarz
1996-12-02T23:59:59.000Z
Infinite-dimensional Grassmannian manifold contains moduli spaces of Riemann surfaces of all genera. This well known fact leads to a conjecture that non-perturbative string theory can be formulated in terms of Grassmannian. We present new facts supporting this hypothesis. In particular, it is shown that Grassmannians can be considered as generalized moduli spaces; this statement permits us to define corresponding "string amplitudes" (at least formally). One can conjecture, that it is possible to explain the relation between non-perturbative and perturbative string theory by means of localization theorems for equivariant cohomology; this conjecture is based on the characterization of moduli spaces, relevant to string theory, as sets consisting of points with large stabilizers in certain groups acting on Grassmannian. We describe an involution on the Grassmannian that could be related to S-duality in string theory.
Reheating and Cosmic String Production
Chao-Jun Feng; Xian Gao; Miao Li; Wei Song; Yushu Song
2008-01-04T23:59:59.000Z
We compute the string production rate at the end of inflation, using the string spectrum obtained in \\lss in a near-de Sitter space. Our result shows that highly excited strings are hardly produced, thus the simple slow-roll inflation alone does not offer a cosmic string production mechanism.
Extended Inflation from Strings
J. Garcia-Bellido; M. quiros
1991-09-25T23:59:59.000Z
We study the possibility of extended inflation in the effective theory of gravity from strings compactified to four dimensions and find that it strongly depends on the mechanism of supersymmetry breaking. We consider a general class of string--inspired models which are good candidates for successful extended inflation. In particular, the $\\omega$--problem of ordinary extended inflation is automatically solved by the production of only very small bubbles until the end of inflation. We find that the inflaton field could belong either to the untwisted or to the twisted massless sectors of the string spectrum, depending on the supersymmetry breaking superpotential.
Improved freezing level retrieval
Hong, Sungwook
2002-01-01T23:59:59.000Z
TRMM Microwave Imager(TMI)-based passive microwave retrieval techniques result in biased estimates of the freezing level and rainfall over the east Pacific in the Inter Tropical Convergence Zone (ITCZ). Passive microwave rainfall estimates...
Perturbative String Thermodynamics near Black Hole Horizons
Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov
2015-07-01T23:59:59.000Z
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.
Perturbative String Thermodynamics near Black Hole Horizons
Thomas G. Mertens; Henri Verschelde; Valentin I. Zakharov
2014-10-29T23:59:59.000Z
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.
String Theory: Progress and Problems
John H. Schwarz
2007-03-05T23:59:59.000Z
String theory builds on the great legacy of Yukawa and Tomonaga: New degrees of freedom and control of the UV are two important themes. This talk will give an overview of some of the progress and some of the unsolved problems that characterize string theory today. It is divided into two parts: (1) Connecting String Theory to the Real World; (2) Gauge Theory/String Theory Duality. Two other major subjects, which I will omit, are Black Holes in String Theory and The Impact of String Theory on Mathematics.
A. Klemm; R. Schimmrigk
1992-04-20T23:59:59.000Z
We investigate a class of (2,2) supersymmetric string vacua which may be represented as Landau--Ginzburg theories with a quasihomogeneous potential which has an isolated singularity at the origin. There are at least three thousand distinct models in this class. All vacua of this type lead to Euler numbers which lie in the range $-960 \\leq \\chi \\leq 960$. The Euler characteristics do not pair up completely hence the space of Landau--Ginzburg ground states is not mirror symmetric even though it exhibits a high degree of symmetry. We discuss in some detail the relation between Landau--Ginzburg models and Calabi--Yau manifolds and describe a subtlety regarding Landau--Ginzburg potentials with an arbitrary number of fields. We also show that the use of topological identities makes it possible to relate Landau-Ginzburg theories to types of Calabi-Yau manifolds for which the usual Landau-Ginzburg framework does not apply.
System engineering approach to GPM retrieval algorithms
Rose, C. R. (Chris R.); Chandrasekar, V.
2004-01-01T23:59:59.000Z
System engineering principles and methods are very useful in large-scale complex systems for developing the engineering requirements from end-user needs. Integrating research into system engineering is a challenging task. The proposed Global Precipitation Mission (GPM) satellite will use a dual-wavelength precipitation radar to measure and map global precipitation with unprecedented accuracy, resolution and areal coverage. The satellite vehicle, precipitation radars, retrieval algorithms, and ground validation (GV) functions are all critical subsystems of the overall GPM system and each contributes to the success of the mission. Errors in the radar measurements and models can adversely affect the retrieved output values. Ground validation (GV) systems are intended to provide timely feedback to the satellite and retrieval algorithms based on measured data. These GV sites will consist of radars and DSD measurement systems and also have intrinsic constraints. One of the retrieval algorithms being studied for use with GPM is the dual-wavelength DSD algorithm that does not use the surface reference technique (SRT). The underlying microphysics of precipitation structures and drop-size distributions (DSDs) dictate the types of models and retrieval algorithms that can be used to estimate precipitation. Many types of dual-wavelength algorithms have been studied. Meneghini (2002) analyzed the performance of single-pass dual-wavelength surface-reference-technique (SRT) based algorithms. Mardiana (2003) demonstrated that a dual-wavelength retrieval algorithm could be successfully used without the use of the SRT. It uses an iterative approach based on measured reflectivities at both wavelengths and complex microphysical models to estimate both No and Do at each range bin. More recently, Liao (2004) proposed a solution to the Do ambiguity problem in rain within the dual-wavelength algorithm and showed a possible melting layer model based on stratified spheres. With the No and Do calculated at each bin, the rain rate can then be calculated based on a suitable rain-rate model. This paper develops a system engineering interface to the retrieval algorithms while remaining cognizant of system engineering issues so that it can be used to bridge the divide between algorithm physics an d overall mission requirements. Additionally, in line with the systems approach, a methodology is developed such that the measurement requirements pass through the retrieval model and other subsystems and manifest themselves as measurement and other system constraints. A systems model has been developed for the retrieval algorithm that can be evaluated through system-analysis tools such as MATLAB/Simulink.
Holger B. Nielsen; Masao Ninomiya
2015-03-10T23:59:59.000Z
Bosonic string theory with the possibility for an arbitrary number of strings - i.e. a string ?eld theory - is formulated by a Hilbert space (a Fock space), which is just that for massless noninteracting scalars. We earlier presented this novel type of string ?eld theory, but now we show that it leads to scattering just given by the Veneziano model amplitude. Generalization to strings with fermion modes would presumably be rather easy. It is characteristic for our formulation /model that: 1) We have thrown away some null set of information compared to usual string ?eld theory, 2)Formulated in terms of our \\objects" (= the non-interacting scalars) there is no interaction and essentially no time development(Heisenberg picture), 3) so that the S-matrix is in our Hilbert space given as the unit matrix, S=1, and 4) the Veneziano scattering amplitude appear as the overlap between the initial and the ?nal state described in terms of the \\objects". 5) The integration in the Euler beta function making up the Veneziano model appear from the summation over the number of \\objects" from one of the incoming strings which goes into a certain one of the two outgoing strings. A correction from Weyl anomaly is needed to get the correct form of the Veneziano amplitude and it only fits for 26 dimensions.
New Retrievable Coil Anchors: Preliminary In Vivo Experiences in Swine
Konya, A., E-mail: akonya@mdanderson.org; Wright, K.C. [University of Texas M.D. Anderson Cancer Center, Section of Interventional Radiology, Division of Diagnostic Imaging (United States)
2005-04-15T23:59:59.000Z
Purpose. To design and test retrievable coil anchors to improve the safety and efficacy of coil embolization. Methods. Fifty-two 0.038-inch homemade retrievable stainless steel coils were equipped with one of four different pre-shaped nitinol anchors and tested in 38 pigs. All coils with the anchor were completely retrieved and redeployed 3-18 times (median 7 times) prior to release. Types 1 and 2 anchored coils were acutely deployed in the external iliac arteries (n = 10 each), and chronically tested (1 week) in the common carotid arteries (n = 6 each). Larger type 1 (n = 4), type 3 (n = 6), and type 4 (n = 4) anchored coils were acutely deployed in the abdominal aorta. The largest type 1 anchors (n = 6) were acutely tested in the inferior vena cava. Results. All anchored coils were successfully retrieved and repositioned several times. All but two coils formed a compact plug and there was no coil migration except with two mechanically defective type 3 anchors. Conclusion. The use of retrievable anchors allowed the coils to be retrieved and repositioned, prevented coil migration, and enabled compact coil configuration.
Miftachul Hadi; Malcolm Anderson; Andri Husein
2014-05-07T23:59:59.000Z
We study nonlinear sigma model, especially Skyrme model without twist and Skyrme model with twist: twisted Skyrmion string. Twist term, $mkz$, is indicated in vortex solution. Necessary condition for stability of vortex solution has consequence that energy of vortex is minimum and scale-free (vortex solution is neutrally stable to changes in scale). We find numerically that the value of vortex minimum energy per unit length for twisted Skyrmion string is $20.37\\times 10^{60}~\\text{eV/m}$.
Keith Dienes
2010-01-08T23:59:59.000Z
We are currently in the throes of a potentially huge paradigm shift in physics. Motivated by recent developments in string theory and the discovery of the so-called "string landscape", physicists are beginning to question the uniqueness of fundamental theories of physics and the methods by which such theories might be understood and investigated. In this colloquium, I will give a non-technical introduction to the nature of this paradigm shift and how it developed. I will also discuss some of the questions to which it has led, and the nature of the controversies it has spawned.
Self-Dual Supergravity from N = 2 Strings
de Boer, J.; Skenderis, K.
1997-09-24T23:59:59.000Z
A new heterotic N = 2 string with manifest target space supersymmetry is constructed by combining a conventional N = 2 string in the right-moving sector and a Green-Schwarz-Berkovits type string in the left-moving sector. The corresponding sigma model is then obtained by turning on background fields for the massless excitations. We compute the beta functions and we partially check the OPE's of the superconformal algebra perturbatively in {alpha}{prime}, all in superspace. The resulting field equations describe N = 1 self-dual supergravity.
Decay of False Vacuum via Fuzzy Monopole in String Theory
Aya Kasai; Yutaka Ookouchi
2015-02-05T23:59:59.000Z
We investigate dielectric branes in false vacua in Type IIB string theory. The dielectric branes are supported against collapsing by lower energy vacua inside spherical or tube-like branes. We claim that such branes can be seeds for semi-classical (or quantum mechanical) decay of the false vacua, which makes the life-time of the false vacua shorter. Also, we discuss a topology change of a bubble corresponding to the fuzzy monopole triggered by dissolving fundamental strings.
Mellin-Barnes Representation of the Topological String
Krefl, Daniel
2015-01-01T23:59:59.000Z
We invoke integrals of Mellin-Barnes type to analytically continue the Gopakumar-Vafa resummation of the topological string free energy in the string coupling constant, leading to additional non-perturbative terms. We also discuss in a similar manner the refined and Nekrasov-Shatashvili limit version thereof. The derivation is straight-forward and essentially boils down to taking residue. This allows us to confirm some related conjectures in the literature at tree-level.
Current balancing for battery strings
Galloway, James H. (New Baltimore, MI)
1985-01-01T23:59:59.000Z
A battery plant is described which features magnetic circuit means for balancing the electrical current flow through a pluraliircuitbattery strings which are connected electrically in parallel. The magnetic circuit means is associated with the battery strings such that the conductors carrying the electrical current flow through each of the battery strings pass through the magnetic circuit means in directions which cause the electromagnetic fields of at least one predetermined pair of the conductors to oppose each other. In an alternative embodiment, a low voltage converter is associated with each of the battery strings for balancing the electrical current flow through the battery strings.
John H. Schwarz
2003-04-28T23:59:59.000Z
The first part of this report gives a very quick sketch of how string theory concepts originated and evolved during its first 25 years (1968-93). The second part presents a somewhat more detailed discussion of the highlights of the past decade. The final part discusses some of the major problems that remain to be solved.
Casalbuoni, Roberto; Gomis, Joaquim; Longhi, Giorgio [Department of Physics, University of Florence, INFN, Florence (Italy) and Galileo Galilei Institute for Theoretical Physics, Florence (Italy); PH-TH Division, CERN, CH -1211 Geneva 23 (Switzerland) and Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, Diagonal 647, 08028 Barcelona (Spain); Department of Physics, University of Florence and INFN, Florence (Italy)
2007-12-15T23:59:59.000Z
We construct a classical nonrelativistic string model in 3+1 dimensions. The model contains a spurion tensor field that is responsible for the noncommutative structure of the model. Under double-dimensional reduction the model reduces to the exotic nonrelativistic particle in 2+1 dimensions.
Device for balancing parallel strings
Mashikian, Matthew S. (Storrs, CT)
1985-01-01T23:59:59.000Z
A battery plant is described which features magnetic circuit means in association with each of the battery strings in the battery plant for balancing the electrical current flow through the battery strings by equalizing the voltage across each of the battery strings. Each of the magnetic circuit means generally comprises means for sensing the electrical current flow through one of the battery strings, and a saturable reactor having a main winding connected electrically in series with the battery string, a bias winding connected to a source of alternating current and a control winding connected to a variable source of direct current controlled by the sensing means. Each of the battery strings is formed by a plurality of batteries connected electrically in series, and these battery strings are connected electrically in parallel across common bus conductors.
Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC; Witten, Edward; /Princeton, Inst. Advanced Study
2006-06-09T23:59:59.000Z
In the context of string theory, axions appear to provide the most plausible solution of the strong CP problem. However, as has been known for a long time, in many string-based models, the axion coupling parameter Fa is several orders of magnitude higher than the standard cosmological bounds. We re-examine this problem in a variety of models, showing that Fa is close to the GUT scale or above in many models that have GUT-like phenomenology, as well as some that do not. On the other hand, in some models with Standard Model gauge fields supported on vanishing cycles, it is possible for Fa to be well below the GUT scale.
A. Gorsky; M. Shifman; A. Yung
2006-01-18T23:59:59.000Z
We address two distinct but related issues: (i) the impact of (two-dimensional) axions in a two-dimensional theory known to model confinement, the CP(N-1) model; (ii) bulk axions in four-dimensional Yang-Mills theory supporting non-Abelian strings. In the first case n, \\bar n kinks play the role of "quarks." They are known to be confined. We show that introduction of axions leads to deconfinement (at very large distances). This is akin to the phenomenon of wall liberation in four-dimensional Yang-Mills theory. In the second case we demonstrate that the bulk axion does not liberate confined (anti)monopoles, in contradistinction with the two-dimensional model. A novel physical effect which we observe is the axion radiation caused by monopole-antimonopole pairs attached to the non-Abelian strings.
Coulomb string tension, asymptotic string tension, and the gluon chain
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Greensite, Jeff; Szczepaniak, Adam P.
2015-02-01T23:59:59.000Z
We compute, via numerical simulations, the non-perturbative Coulomb potential and position-space ghost propagator in pure SU(3) gauge theory in Coulomb gauge. We find that that the Coulomb potential scales nicely in accordance with asymptotic freedom, that the Coulomb potential is linear in the infrared, and that the Coulomb string tension is about four times larger than the asymptotic string tension. We explain how it is possible that the asymptotic string tension can be lower than the Coulomb string tension by a factor of four.
International Association for Cryptologic Research (IACR)
databases while keeping their queries secret from the database managers. We propose a new model for PIR, utilizing auxiliary random servers to provide privacy services for database access. In this model, prior. In this model, the database is viewed as an nbit string x out of which the user retrieves the ith bit x i
Physics of String Flux Compactifications
Frederik Denef; Michael R. Douglas; Shamit Kachru
2007-01-06T23:59:59.000Z
We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.
The SSC Full Cell Prototype String Test
McInturff, A.D.
2011-01-01T23:59:59.000Z
the Proceedings The SSC Full Cell Prototype String Test A.D.AC03-76SFOOO98. The SSC Full Cell Prototype String Test P.the Proceedings The SSC Full Cell Prototype String Test A.D.
Phase Retrieval: Hubble and the
Masci, Frank
(Gerchberg-Saxton/Misell/Fienup) Gradient search (steepest descent, conjugate gradient, . . .) Damped least squares (Newton-Raphson) Neural network Linear programming Prescription retrieval Phase diversity etc
RHIC | String Theory Predicts an Experimental Result
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
that originally appeared in the online publication symmetry breaking. A first: String theory predicts an experimental result One of the biggest criticisms of string theory is that...
Waste Emplacement/Retrieval System Description Document
Eric Loros
2001-07-25T23:59:59.000Z
The Waste Emplacement/Retrieval System transports Waste Packages (WPs) from the Waste Handling Building (WHB) to the subsurface area of emplacement, and emplaces the WPs once there. The Waste Emplacement/Retrieval System also, if necessary, removes some or all of the WPs from the underground and transports them to the surface. Lastly, the system is designed to remediate abnormal events involving the portions of the system supporting emplacement or retrieval. During emplacement operations, the system operates on the surface between the WHB and North Portal, and in the subsurface in the North Ramp, access mains, and emplacement drifts. During retrieval or abnormal conditions, the operations areas may also extend to a surface retrieval storage site and South Portal on the surface, and the South Ramp in the subsurface. A typical transport and emplacement operation involves the following sequence of events. A WP is loaded into a WP transporter at the WHB, and coupled to a pair of transport locomotives. The locomotives transport the WP from the WHB, down the North Ramp, and to the entrance of an emplacement drift. Once docked at the entrance of the emplacement drift, the WP is moved outside of the WP transporter, and engaged by a WP emplacement gantry. The WP emplacement gantry lifts the WP, and transports it to its emplacement location, where the WP is then lowered to its final resting position. The WP emplacement gantry remains in the drift while the WP transporter is returned to the WHB by the locomotives. When the transporter reaches the WHB, the sequence of operations is repeated. Retrieval of all the WPs, or a large group of WPs, under normal conditions is achieved by reversing the emplacement operations. Retrieval of a small set of WPs, under normal or abnormal conditions, is known as recovery. Recovery performed under abnormal conditions will involve a suite of specialized equipment designed to perform a variety of tasks to enable the recovery process. Recovery after abnormal events may require clearing of equipment, rock, and ground support to facilitate recovery operations. Stabilization of existing ground support and installation of new ground support may also be needed. Recovery of WP(s) after an event that has contaminated drifts and/or WPs will require limiting the spread of contamination. Specialized equipment will also be necessary for system restoration (e.g., after a derailment, component failure). The Waste Emplacement/Retrieval System interfaces with the Subsurface Facility System and Ground Control System for the size and layout of the underground openings. The system interfaces with the Subsurface Ventilation System for the emplacement drift operating environment and the size of the drift isolation doors. The system interfaces with all WP types for the size, weight, and other important parameters affecting emplacement, recovery, and retrieval. The system interfaces with the Subsurface Emplacement Transportation System for the rail system upon which it operates and the distribution of power through the rail system. The system interfaces with the Monitored Geologic Repository (MGR) Operations Monitoring and Control System for the transmission of data to and from the system equipment, and for remote control of system equipment. The system interfaces with the Ground Control System for any repairs that are made. The system interfaces with the Emplacement Drift System for the WP emplacement mode and hardware. The system interfaces with the Disposal Container Handling System and the Waste Handling Building System for the receipt (during emplacement) and delivery (during retrieval/recovery) of WPs.
Twist Field as Three String Interaction Vertex in Light Cone String Field Theory
Isao Kishimoto; Sanefumi Moriyama; Shunsuke Teraguchi
2007-03-22T23:59:59.000Z
It has been suggested that matrix string theory and light-cone string field theory are closely related. In this paper, we investigate the relation between the twist field, which represents string interactions in matrix string theory, and the three-string interaction vertex in light-cone string field theory carefully. We find that the three-string interaction vertex can reproduce some of the most important OPEs satisfied by the twist field.
Summing Planar Bosonic Open Strings
Bardakci, Korkut
2006-02-16T23:59:59.000Z
In earlier work, planar graphs of massless {phi}{sup 3} theory were summed with the help of the light cone world sheet picture and the mean field approximation. In the present article, the same methods are applied to the problem of summing planar bosonic open strings. They find that in the ground state of the system, string boundaries form a condensate on the world sheet, and a new string emerges from this summation. Its slope is always greater than the initial slope, and it remains non-zero even when the initial slope is set equal to zero. If they assume the initial string tends to a field a theory in the zero slope limit, this result provides evidence for string formation in field theory.
David J. Gross; Washington Taylor
2001-06-04T23:59:59.000Z
We describe projection operators in the matter sector of Witten's cubic string field theory using modes on the right and left halves of the string. These projection operators represent a step towards an analytic solution of the equations of motion of the full string field theory, and can be used to construct Dp-brane solutions of the string field theory when the BRST operator Q is taken to be pure ghost, as suggested in the recent conjecture by Rastelli, Sen and Zwiebach. We show that a family of solutions related to the sliver state are rank one projection operators on the appropriate space of half-string functionals, and we construct higher rank projection operators corresponding to configurations of multiple D-branes.
David J. Gross; Washington Taylor
2001-06-27T23:59:59.000Z
We describe the ghost sector of cubic string field theory in terms of degrees of freedom on the two halves of a split string. In particular, we represent a class of pure ghost BRST operators as operators on the space of half-string functionals. These BRST operators were postulated by Rastelli, Sen, and Zwiebach to give a description of cubic string field theory in the closed string vacuum arising from condensation of a D25-brane in the original tachyonic theory. We find a class of solutions for the ghost equations of motion using the pure ghost BRST operators. We find a vanishing action for these solutions, and discuss possible interpretations of this result. The form of the solutions we find in the pure ghost theory suggests an analogous class of solutions in the original theory on the D25-brane with BRST operator Q_B coupling the matter and ghost sectors.
Emergence String and Mass Formulas of Hadrons
Yi-Fang Chang
2011-07-19T23:59:59.000Z
Assume that hadrons are formed from the emergence string. Usual string should possess two moving states: oscillation and rotation, so we propose corresponding potential and the equation of the emergence string, whose energy spectrum is namely the GMO mass formula and its modified accurate mass formula. These are some relations between the string and observable experimental data.
Strings, higher curvature corrections, and black holes
Thomas Mohaupt
2005-12-05T23:59:59.000Z
We review old and recent results on subleading contributions to black hole entropy in string theory.
Accidental inflation in string theory
Linde, Andrei; Westphal, Alexander, E-mail: alinde@stanford.edu, E-mail: awestpha@stanford.edu [Department of Physics, Stanford University, Stanford, CA 94305-4060 (United States)
2008-03-15T23:59:59.000Z
We show that inflation in type IIB string theory driven by the volume modulus can be realized in the context of the racetrack-based Kallosh-Linde model (KL) of moduli stabilization. Inflation here arises through the volume modulus slow-rolling down from a flat hilltop or inflection point of the scalar potential. This situation can be quite generic in the landscape, where by uplifting one of the two adjacent minima one can turn the barrier either into a flat saddle point or into an inflection point supporting eternal inflation. The resulting spectral index is tunable in the range of 0.93{approx}
String Junctions and Holographic Interfaces
Marco Chiodaroli; Michael Gutperle; Ling-Yan Hung; Darya Krym
2010-11-22T23:59:59.000Z
In this paper we study half-BPS type IIB supergravity solutions with multiple $AdS_3\\times S^3\\times M_4$ asymptotic regions, where $M_4$ is either $T^4$ or $K_3$. These solutions were first constructed in [1] and have geometries given by the warped product of $AdS_2 \\times S^2 \\times M_4 $ over $\\Sigma$, where $\\Sigma$ is a Riemann surface. We show that the holographic boundary has the structure of a star graph, i.e. $n$ half-lines joined at a point. The attractor mechanism and the relation of the solutions to junctions of self-dual strings in six-dimensional supergravity are discussed. The solutions of [1] are constructed introducing two meromorphic and two harmonic functions defined on $\\Sigma$. We focus our analysis on solutions corresponding to junctions of three different conformal field theories and show that the conditions for having a solution charged only under Ramond-Ramond three-form fields reduce to relations involving the positions of the poles and the residues of the relevant harmonic and meromorphic functions. The degeneration limit in which some of the poles collide is analyzed in detail. Finally, we calculate the holographic boundary entropy for a junction of three CFTs and obtain a simple expression in terms of poles and residues.
B polarization of the cosmic microwave background as a tracer of strings
Seljak, Uros [Department of Physics, Princeton University, Princeton New Jersey 08544 (United States); International Center for Theoretical Physics, Trieste (Italy); Slosar, Anze [Faculty of Mathematics and Physics, University of Ljubljana (Slovenia)
2006-09-15T23:59:59.000Z
String models can produce successful inflationary scenarios in the context of brane collisions, and in many of these models cosmic strings may also be produced. In scenarios such as Kachru-Kallosh-Linde-Maldacena-McAllister-Trivedi (KKLMMT) scenario the string contribution is naturally predicted to be well below the inflationary signal for cosmic microwave background (CMB) temperature anisotropies, in agreement with the existing limits. We find that for B type polarization of CMB the situation is reversed and the dominant signal comes from vector modes generated by cosmic strings, which exceeds the gravity wave signal from both inflation and strings. The signal can be detected for a broad range of parameter space; future polarization experiments may be able to detect the string signal down to the string tension G{mu}=10{sup -9}, although foregrounds and lensing are likely to worsen these limits. We argue that the optimal scale to search for the string signature is at l{approx}1000, but in models with high optical depth the signal from reionization peak at large scales is also significant. The shape of the power spectrum allows one to distinguish the string signature from the gravity waves from inflation, but only with a sufficiently high angular resolution experiment.
C. S. Lam
1994-06-24T23:59:59.000Z
A low energy string theory should reduce to an ordinary quantum field theory, but in reality the structures of the two are so different as to make the equivalence obscure. The string formalism is more symmetrical between the spacetime and the internal degrees of freedom, thus resulting in considerable simplification in practical calculations and novel insights in theoretical understandings. We review here how tree or multiloop field-theoretical diagrams can be organized in a string-like manner to take advantage of this computational and conceptual simplicity.
Radio bursts from superconducting strings
Yi-Fu Cai; Eray Sabancilar; Tanmay Vachaspati
2012-01-30T23:59:59.000Z
We show that radio bursts from cusps on superconducting strings are linearly polarized, thus, providing a signature that can be used to distinguish them from astrophysical sources. We write the event rate of string-generated radio transients in terms of observational variables, namely, the event duration and flux. Assuming a canonical set of observational parameters, we find that the burst event rate can be quite reasonable, e.g., order ten a year for Grand Unified strings with 100 TeV currents, and a lack of observed radio bursts can potentially place strong constraints on particle physics models.
Radio Broadcasts from Superconducting Strings
Yi-Fu Cai; Eray Sabancilar; Daniele A. Steer; Tanmay Vachaspati
2012-05-14T23:59:59.000Z
Superconducting cosmic strings can give transient electromagnetic signatures that we argue are most evident at radio frequencies. We investigate the three different kinds of radio bursts from cusps, kinks, and kink-kink collisions on superconducting strings. We find that the event rate is dominated by kink bursts in a range of parameters that are of observational interest, and can be quite high (several a day at 1 Jy flux) for a canonical set of parameters. In the absence of events, the search for radio transients can place stringent constraints on superconducting cosmic strings.
A note on the string spectrum at the Hagedorn temperature
J. D. Madrigal; P. Talavera
2009-05-21T23:59:59.000Z
We discuss semi-classical string configurations at finite temperature. We find that those soliton solution in the background describing type IIA strings disappear or become divergent when we approach the Hagedorn temperature in the strong coupling regime. These findings together with a semi-classical analysis for the Hawking radiation let us to think that Hawking radiation is mainly driven by the existence of highly excited states. As by side, we check that beside the thermodynamical instability the system is dynamical unstable before reaching the Hagedorn temperature.
Power Towers of String Instantons for N=1 Vacua
Ralph Blumenhagen; Maximilian Schmidt-Sommerfeld
2008-03-11T23:59:59.000Z
We provide arguments for the existence of novel hereinafter called poly-instanton corrections to holomorphic couplings in four-dimensional N=1 supersymmetric string compactifications. After refining quantitatively the D-brane instanton calculus for corrections to the gauge kinetic function, we explicitly apply it to the Type I toroidal orbifold defined in arXiv:0710.3080 and compare the results to the proposed heterotic S-dual model. This leads us to the intriguing conclusion that N=1 string vacua feature a power tower like proliferation of instanton corrections.
String Theory: The Early Years
John H. Schwarz
2000-07-26T23:59:59.000Z
Lenny Susskind has made many important contributions to theoretical physics during the past 35 years. In this talk I will discuss the early history of string theory (1968-72) emphasizing Susskind's contributions.
String Theory Origins of Supersymmetry
John H. Schwarz
2000-11-09T23:59:59.000Z
The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincar\\'e algebra, motivated Wess and Zumino to construct supersymmetric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the spacetime supersymmetry of the string theory in 1976, a fact that was proved five years later by Green and myself.
Waste Emplacement/Retrieval System Description Document
NONE
2000-10-12T23:59:59.000Z
The Waste Emplacement/Retrieval System transports Waste Packages (WPs) from the Waste Handling Building (WHB) to the subsurface area of emplacement, and emplaces the WPs once there. The system also, if necessary, removes some or all of the WPs from the underground and transports them to the surface. Lastly, the system is designed to remediate abnormal events involving the portions of the system supporting emplacement or retrieval. During emplacement operations, the system operates on the surface between the WHB and North Portal, and in the subsurface in the North Ramp, access mains, and emplacement drifts. During retrieval or abnormal conditions, the operations areas may also extend to a surface retrieval storage site and South Portal on the surface, and the South Ramp in the subsurface. A typical transport and emplacement operation involves the following sequence of events. A WP is loaded into a WP transporter at the WHB, and coupled to a pair of transport locomotives. The locomotives transport the WP from the WHB, down the North Ramp, and to the entrance of an emplacement drift. Once docked at the entrance of the emplacment drift, the WP is moved outside of the WP transporter, and engaged by a WP emplacement gantry. The gantry lifts the WP, and transports it to its emplacement location, where the WP is then lowered to its final resting position. The gantry remains in the drift while the WP transporter is returned to the WHB by the locomotives. When the transporter reaches the WHB, the sequence of operations is repeated. Retrieval of all the WPs, or a large group of WPs, under normal conditions is achieved by reversing the emplacement operations. Retrieval of a small set of WPs, under normal or abnormal conditions, is known as recovery. Recovery performed under abnormal conditions will involve a suite of specialized equipment designed to perform a variety of tasks to enable the recovery process. Recovery after abnormal events may require clearing of equipment, rock, and ground support to facilitate recovery operations. Stabilization of existing ground support and installation of new ground support may also be needed. Recovery of WPs after an event that has contaminated drifts and/or WPs will require limiting the spread of contamination. Specialized equipment will also be necessary for system restoration. The system interfaces with the Subsurface Facility System and Ground Control System for the size and layout of the underground openings. The system interfaces with the Subsurface Ventilation System for the emplacement drift operating environment and the size of the drift isolation doors. The system interfaces with all WP types for the size, weight, and other important parameters affecting emplacement, recovery, and retrieval. The system interfaces with the Subsurface Emplacement Transportation System for the rail system upon which it operates and the distribution of power throuch the rail system. The system interfaces with the Monitored Geologic Repository (MGR) Operations Monitoring and Control System for the transmission of data to and from the system equipment, and for remote control of system equipment. The system interfaces with the Ground Control System for any repairs that are made. The system interfaces with the Emplacement Drift System for the WP emplacement mode and hardware. The system interfaces with the Disposal Container Handling System and the Waste Handling Building System for the receipt (during emplacement) and delivery (during retrieval/recovery) of WPs.
Use of Retrievable Compared to Permanent Inferior Vena Cava Filters: A Single-Institution Experience
Ha, Thuong G. Van [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States)], E-mail: tgvanha@uchicago.edu; Chien, Andy S. [Pritzker School of Medicine, University of Chicago (United States); Funaki, Brian S.; Lorenz, Jonathan [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States); Piano, Giancarlo [University of Chicago, Department of Surgery (United States); Shen, Maxine [Pritzker School of Medicine, University of Chicago (United States); Leef, Jeffrey [University of Chicago, Department of Radiology, Section of Vascular and Interventional Radiology (United States)
2008-03-15T23:59:59.000Z
The purpose of this study was to review the use, safety, and efficacy of retrievable inferior vena cava (IVC) filters in their first 5 years of availability at our institution. Comparison was made with permanent filters placed in the same period. A retrospective review of IVC filter implantations was performed from September, 1999, to September, 2004, in our department. These included both retrievable and permanent filters. The Recovery nitinol and Guenther tulip filters were used as retrievable filters. The frequency of retrievable filter used was calculated. Clinical data and technical data related to filter placement were reviewed. Outcomes, including pulmonary embolism, complications associated with placement, retrieval, or indwelling, were calculated. During the study period, 604 IVC filters were placed. Of these, 97 retrievable filters (16%) were placed in 96 patients. There were 53 Recovery filter and 44 Tulip filter insertions. Subjects were 59 women and 37 men; the mean age was 52 years, with a range of from 18 to 97 years. The placement of retrievable filters increased from 2% in year 1 to 32% in year 5 of the study period. The total implantation time for the permanent group was 145,450 days, with an average of 288 days (range, 33-1811 days). For the retrievable group, the total implantation time was 21,671 days, with an average of 226 days (range, 2-1217 days). Of 29 patients who returned for filter retrieval, the filter was successfully removed in 28. There were 14 of 14 successful Tulip filter retrievals and 14 of 15 successful Recovery filter retrievals. In one patient, after an indwelling period of 39 days, a Recovery nitinol filter could not be removed secondary to a large clot burden within the filter. For the filters that were removed, the mean dwell time was 50 days for the Tulip type and 20 days for the Recovery type. Over the follow-up period there was an overall PE incidence of 1.4% for the permanent group and 1% for the retrieval group. In conclusion, there was an increase in the use of retrievable filters over the study period and an overall increase in the total number of filters implanted. The increased use of these filters appeared to be due to expanded indications predicated by their retrievability. Placement and retrieval of these filters have a low risk of complications, and retrievable filters appeared effective, as there was low rate of clinically significant pulmonary embolism associated with these filters during their indwelling time.
Semantic-Sensitive Web Information Retrieval Model for HTML Documents
Bassil, Youssef
2012-01-01T23:59:59.000Z
With the advent of the Internet, a new era of digital information exchange has begun. Currently, the Internet encompasses more than five billion online sites and this number is exponentially increasing every day. Fundamentally, Information Retrieval (IR) is the science and practice of storing documents and retrieving information from within these documents. Mathematically, IR systems are at the core based on a feature vector model coupled with a term weighting scheme that weights terms in a document according to their significance with respect to the context in which they appear. Practically, Vector Space Model (VSM), Term Frequency (TF), and Inverse Term Frequency (IDF) are among other long-established techniques employed in mainstream IR systems. However, present IR models only target generic-type text documents, in that, they do not consider specific formats of files such as HTML web documents. This paper proposes a new semantic-sensitive web information retrieval model for HTML documents. It consists of a...
Acoustic data transmission through a drill string
Drumheller, D.S.
1988-04-21T23:59:59.000Z
Acoustical signals are transmitted through a drill string by canceling upward moving acoustical noise and by preconditioning the data in recognition of the comb filter impedance characteristics of the drill string. 5 figs.
Quadratic superconducting cosmic strings revisited
Mustapha Azreg-Aďnou
2008-02-22T23:59:59.000Z
It has been shown that 5-dimensional general relativity action extended by appropriate quadratic terms admits a singular superconducting cosmic string solution. We search for cosmic strings endowed with similar and extended physical properties by directly integrating the non-linear matrix field equations thus avoiding the perturbative approach by which we constructed the above-mentioned \\textsl{exact} solution. The most general superconducting cosmic string, subject to some constraints, will be derived and shown to be mathematically \\textsl{unique} up to linear coordinate transformations mixing its Killing vectors. The most general solution, however, is not globally equivalent to the old one due to the existence of Killing vectors with closed orbits.
Sustainability of multi-field inflation and bound on string scale
Jinn-Ouk Gong
2009-02-11T23:59:59.000Z
We study the effects of the interaction terms between the inflaton fields on the inflationary dynamics in multi-field models. With power law type potential and interactions, the total number of e-folds may get considerably reduced and can lead to unacceptably short period of inflation. Also we point out that this can place a bound on the characteristic scale of the underlying theory such as string theory. Using a simple multi-field chaotic inflation model from string theory, the string scale is constrained to be larger than the scale of grand unified theory.
String Theory at Snowmass Michael Dine
California at Santa Cruz, University of
String Theory at Snowmass Michael Dine Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, CA 95064 (Dated: September 23, 2002) This is the summary talk for the String Theory interested in string theory, quantum gravity, and related issues met to discuss the questions: which future
Non-Abelian Strings and Axions
Shifman, M. [William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN 55455 (United States)
2010-08-30T23:59:59.000Z
Axion-like fields can have a strong impact on non-Abelian strings. I discuss axion connection to such strings and its implications in two cases: (i) axion localized on the strings, and (ii) axions propagating in the four-dimensional bulk.
Introduction to the theory of strings
Peskin, M.E.
1985-10-01T23:59:59.000Z
These lectures present, from an introductory perspective, some basic aspects of the quantum theory of strings. They treat (1) the kinematics, spectrum, and scattering amplitude of the bosonic string, (2) the spectrum and supersymmetry of Green-Schwarz superstring, and (3) the identification of the underlying gauge invariances of the string theory. 43 refs.
On Fusion of Effective Retrieval Strategies in the Same Information Retrieval System
On Fusion of Effective Retrieval Strategies in the Same Information Retrieval System Steven M the use of data fusion techniques. Although these improvements have been observed from the fusion effective retrieval strategies in the same information retrieval system. From this, we show that data fusion
5, 243286, 2005 Retrieval of ozone
Paris-Sud XI, Université de
ACPD 5, 243286, 2005 Retrieval of ozone column content during SOLVE II J. M. Livingston et al and Physics Discussions Retrieval of ozone column content from airborne Sun photometer measurements during Aerospace Center), Oberpfaffenhofen, Wessling, Germany 243 #12;ACPD 5, 243286, 2005 Retrieval of ozone
Web Information Retrieval Web Science Course
Nejdl, Wolfgang
1 Web Information Retrieval Web Science Course #12;2 #12;What to Expect · Information Retrieval on the Web Differences to traditional IR · Selected Papers 3 #12;4 Information Retrieval Basics #12 documents on the Internet Searching the World Wide Web #12;16 Recent IR History · 2000's Link analysis
Gordon Chalmers; Olaf Lechtenfeld; Bernd Niemeyer
2000-09-08T23:59:59.000Z
We calculate the genus-one three- and four-point amplitudes in the 2+2 dimensional closed N=(2,2) worldsheet supersymmetric string within the RNS formulation. Vertex operators are redefined with the incorporation of spinor helicity techniques, and the quantum scattering is shown to be manifestly gauge and Lorentz invariant after normalizing the string states. The continuous spin structure summation over the monodromies of the worldsheet fermions is carried out explicitly, and the field-theory limit is extracted. The amplitude in this limit is shown to be the maximally helicity violating amplitude in pure gravity evaluated in a two-dimensional setting, which vanishes, unlike the four-dimensional result. The vanishing of the genus-one N=2 closed string amplitude is related to the absence of one-loop divergences in dimensionally regulated IIB supergravity. Comparisons and contrasts between self-dual field theory and the N=2 string theory are made at the quantum level; they have different S-matrices. Finally, we point to further relations with self-dual field theory and two-dimensional models.
ARM - PI Product - Combined Retrieval, Microphysical Retrievals & Heating
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt Documentation ARMupwelling irradiance ARM DataRates ProductsCombined Retrieval, Microphysical
Type A Accident Investigation Board Report on the February 20...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
February 20, 1996, Fall Fatality at the Radioactive Waste Management Complex Transuranic Storage Area - Retrieval Enclosure, Idaho National Engineering Laboratory Type A Accident...
Cosmic strings in $f\\left(R,L_m\\right)$ gravity
Tiberiu Harko; Matthew J. Lake
2015-01-17T23:59:59.000Z
We consider Kasner type static, cylindrically symmetric interior string solutions in the $f\\left(R,L_m\\right)$ theory of modified gravity. The physical properties of the string are described by an anisotropic energy-momentum tensor satisfying the condition $T_t^t=T_z^z$; that is, the energy density of the string along the $z$-axis is equal to minus the string tension. As a first step in our study we obtain the gravitational field equations in the $f\\left(R,L_m\\right)$ theory for a general static, cylindrically symmetric metric, and then for a Kasner type metric, in which the metric tensor components have a power law dependence on the radial coordinate $r$. String solutions in two particular modified gravity models are investigated in detail. The first is the so-called "exponential" modified gravity, in which the gravitational action is proportional to the exponential of the sum of the Ricci scalar and matter Lagrangian, and the second is the "self-consistent model", obtained by explicitly determining the gravitational action from the field equations under the assumption of a power law dependent matter Lagrangian. In each case, the thermodynamic parameters of the string, as well as the precise form of the matter Lagrangian, are explicitly obtained.
Hall, David R. (Provo, UT); Pixton, David S. (Lehi, UT); Briscoe, Michael (Lehi, UT); McPherson, James (Sandy, UT)
2007-12-04T23:59:59.000Z
A filter for a drill string comprises a perforated receptacle having an open end and a perforated end and first and second mounting surfaces are adjacent the open end. A transmission element is disposed within each of the first and second mounting surfaces. A capacitor may modify electrical characteristics of an LC circuit that comprises the transmission elements. The respective transmission elements are in communication with each other and with a transmission network integrated into the drill string. The transmission elements may be inductive couplers, direct electrical contacts, or optical couplers. In some embodiments of the present invention, the filter comprises an electronic component. The electronic component may be selected from the group consisting of a sensor, a router, a power source, a clock source, a repeater, and an amplifier.
Cosmological consequences of string axions
Kain, Ben [Department of Physics, University of California and Theoretical Physics Group, Bldg. 50A5104, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)
2006-06-15T23:59:59.000Z
Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} > or approx. 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T < or approx. {lambda}{sub QCD}.
Cosmological Consequences of String Axions
Kain, Ben
2005-12-15T23:59:59.000Z
Axion fluctuations generated during inflation lead to isocurvature and non-Gaussian temperature fluctuations in the cosmic microwave background radiation. Following a previous analysis for the model independent string axion we consider the consequences of a measurement of these fluctuations for two additional string axions. We do so independent of any cosmological assumptions except for the axions being massless during inflation. The first axion has been shown to solve the strong CP problem for most compactifications of the heterotic string while the second axion, which does not solve the strong CP problem, obeys a mass formula which is independent of the axion scale. We find that if gravitational waves interpreted as arising from inflation are observed by the PLANCK polarimetry experiment with a Hubble constant during inflation of H{sub inf} {approx}> 10{sup 13} GeV the existence of the first axion is ruled out and the second axion cannot obey the scale independent mass formula. In an appendix we quantitatively justify the often held assumption that temperature corrections to the zero temperature QCD axion mass may be ignored for temperatures T {approx}< {Lambda}{sub QCD}.
Loop Gas Model for Open Strings
V. Kazakov; I. Kostov
1992-05-18T23:59:59.000Z
The open string with one-dimensional target space is formulated in terms of an SOS, or loop gas, model on a random surface. We solve an integral equation for the loop amplitude with Dirichlet and Neumann boundary conditions imposed on different pieces of its boundary. The result is used to calculate the mean values of order and disorder operators, to construct the string propagator and find its spectrum of excitations. The latter is not sensible neither to the string tension $\\L$ nor to the mass $\\mu$ of the ``quarks'' at the ends of the string. As in the case of closed strings, the SOS formulation allows to construct a Feynman diagram technique for the string interaction amplitudes.
Energy radiated from a fluctuating selfdual string
Andreas Gustavsson
2005-06-06T23:59:59.000Z
We compute the energy that is radiated from a fluctuating selfdual string in the large $N$ limit of $A_{N-1}$ theory using the AdS-CFT correspondence. We find that the radiated energy is given by a non-local expression integrated over the string world-sheet. We also make the corresponding computation for a charged string in six-dimensional classical electrodynamics, thereby generalizing the Larmor formula for the radiated energy from an accelerated point particle.
Gamma Ray Bursts from Ordinary Cosmic Strings
R. H. Brandenberger; A. T. Sornborger; M. Trodden
1993-02-12T23:59:59.000Z
We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.
String theory: big problem for small size
S. Sahoo
2012-09-25T23:59:59.000Z
String theory is the most promising candidate theory for a unified description of all fundamental forces exist in the nature. It provides a mathematical framework that combine quantum theory with Einstein's general theory of relativity. But due to the extremely small size of strings, nobody has been able to detect it directly in the laboratory till today. In this article, we have presented a general introduction to string theory.
$O(d,d)$-Covariant String Cosmology
M. Gasperini; G. Veneziano
1991-12-17T23:59:59.000Z
The recently discovered $O(d,d)$ symmetry of the space of slowly varying cosmological string vacua in $d+1$ dimensions is shown to be preserved in the presence of bulk string matter. The existence of $O(d,d)$ conserved currents allows all the equations of string cosmology to be reduced to first-order differential equations. The perfect-fluid approximation is not $O(d,d)$-invariant, implying that stringy fluids possess in general a non-vanishing viscosity.
Gauge Transformations in String Field Theory and canonical Transformation in String Theory
J. Maharana; S. mukherji
1992-01-24T23:59:59.000Z
We study how canonical transfomations in first quantized string theory can be understood as gauge transformations in string field theory. We establish this fact by working out some examples. As a by product, we could identify some of the fields appearing in string field theory with their counterparts in the $\\sigma$-model.
Aspects of noncommutativity in field theory, strings and membranes
Kuldeep Kumar
2008-12-30T23:59:59.000Z
We study certain aspects of noncommutativity in field theory, strings and membranes. We analyse the dynamics of an open membrane whose boundary is attached to p-branes. Noncommutative features of the boundary string coordinates are revealed by algebraic consistency arguments. Next, we derive Seiberg-Witten-type maps relating currents and their divergences in nonabelian U(N) noncommutative gauge theory with the corresponding expressions in the ordinary (commutative) description. We then exploit these maps to obtain the O(\\theta) structure of the commutator anomalies in noncommutative electrodynamics. Finally, we discuss the issue of violation of Lorentz invariance in noncommutative gauge theories by explicitly deriving, following a Noether-like approach, the criteria for preserving Poincare invariance. We also study general (deformed) conformal-Poincare (Galilean) symmetries consistent with relativistic (nonrelativistic) canonical noncommutative spaces.
ARM Cloud Retrieval Ensemble Data Set (ACRED)
Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z
2011-09-12T23:59:59.000Z
This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.
A RETRIEVAL PATTERN-BASED INTER-QUERY LEARNING APPROACH FOR CONTENT-BASED IMAGE RETRIEVAL
Qi, Xiaojun
-query learning (a.k.a., short- term learning) to perform query tuning in a single retrieval session. Recently, inter-query learning (a.k.a., long-term learning) has been employed to further improve retrieval
Source Code Retrieval using Conceptual Similarity
de Rijke, Maarten
researched at least since the mid-late 1980s (Frakes and Ne- jmeh, 1987). Early forms of code retrieval were
Yang, Maria
Data Mining for Thesaurus Generation in Informal Design Information Retrieval Maria C. Yang-offs with each type of thesaurus, especially concerning the resources required to build them as well
Single Shell Tank (SST) Retrieval Sequence FY 2000 Update
GARFIELD, J.S.
2000-09-27T23:59:59.000Z
This document describes the baseline single-shell tank (SST) waste retrieval sequence for the River Protection Project (RPP) updated for Fiscal Year 2000. The SST retrieval sequence identifies the proposed retrieval order (sequence), the tank selection and prioritization rationale, and planned retrieval dates for Hanford SSTs. In addition, the tank selection criteria and reference retrieval method for this sequence are discussed.
Efficient Aho-Corasick String Matching on Emerging Multicore Architectures
Tumeo, Antonino; Villa, Oreste; Secchi, Simone; Chavarría-Miranda, Daniel
2013-12-12T23:59:59.000Z
String matching algorithms are critical to several scientific fields. Beside text processing and databases, emerging applications such as DNA protein sequence analysis, data mining, information security software, antivirus, ma- chine learning, all exploit string matching algorithms [3]. All these applica- tions usually process large quantity of textual data, require high performance and/or predictable execution times. Among all the string matching algorithms, one of the most studied, especially for text processing and security applica- tions, is the Aho-Corasick algorithm. 1 2 Book title goes here Aho-Corasick is an exact, multi-pattern string matching algorithm which performs the search in a time linearly proportional to the length of the input text independently from pattern set size. However, depending on the imple- mentation, when the number of patterns increase, the memory occupation may raise drastically. In turn, this can lead to significant variability in the performance, due to the memory access times and the caching effects. This is a significant concern for many mission critical applications and modern high performance architectures. For example, security applications such as Network Intrusion Detection Systems (NIDS), must be able to scan network traffic against very large dictionaries in real time. Modern Ethernet links reach up to 10 Gbps, and malicious threats are already well over 1 million, and expo- nentially growing [28]. When performing the search, a NIDS should not slow down the network, or let network packets pass unchecked. Nevertheless, on the current state-of-the-art cache based processors, there may be a large per- formance variability when dealing with big dictionaries and inputs that have different frequencies of matching patterns. In particular, when few patterns are matched and they are all in the cache, the procedure is fast. Instead, when they are not in the cache, often because many patterns are matched and the caches are continuously thrashed, they should be retrieved from the system memory and the procedure is slowed down by the increased latency. Efficient implementations of string matching algorithms have been the fo- cus of several works, targeting Field Programmable Gate Arrays [4, 25, 15, 5], highly multi-threaded solutions like the Cray XMT [34], multicore proces- sors [19] or heterogeneous processors like the Cell Broadband Engine [35, 22]. Recently, several researchers have also started to investigate the use Graphic Processing Units (GPUs) for string matching algorithms in security applica- tions [20, 10, 32, 33]. Most of these approaches mainly focus on reaching high peak performance, or try to optimize the memory occupation, rather than looking at performance stability. However, hardware solutions supports only small dictionary sizes due to lack of memory and are difficult to customize, while platforms such as the Cell/B.E. are very complex to program.
TeV Scale Strings and Scattering Amplitudes at the LHC
Dean Carmi
2015-08-16T23:59:59.000Z
We study aspects of TeV string scale models of intersecting D-branes. The gauge bosons arise from strings ending on stacks of D-branes, whereas chiral matter arises from strings stretched between intersecting D-branes. Our focus is on scattering amplitudes (at tree-level), Regge states (string excitations), and collider phenomenology. Achieving a low string scale is possible in models of Large extra dimensions. At the LHC, a low enough string scale implies that cross sections will deviate from their standard model predictions. Moreover, Regge states as well as Kaluza-Klein states and winding states may be produced. In a large class of intersecting D-brane models, the quark-gluon amplitudes with at most 2 quarks turn out to be independent of the geometry of the extra dimensions. Therefore these type of amplitudes, which we call "universal amplitudes", are model independent. The universal amplitudes involve exchanges of Regge states only, whereas amplitudes with more then 2 quarks also involve exchanges of KK and winding states. The main computational part of this work is concerned with suggesting methods to calculate the decay widths of the Regge states, and with the formalism for treating amplitudes containing exchanges of higher spin particles.
Energy Production in the Formation of a Finite Thickness Cosmic String
I. Brevik; A. G. Frřseth
1999-09-29T23:59:59.000Z
The classical electromagnetic modes outside a long, straight, superconducting cosmic string are calculated, assuming the string to be surrounded by a superconducting cylindric surface of radius R. Thereafter, by use of a Bogoliubov-type argument, the electromagnetic energy W produced per unit length in the lowest two modes is calculated when the string is formed "suddenly". The essential new element in the present analysis as compared with prior work of Parker [Phys. Rev. Lett. {\\bf 59}, 1369 (1987)] and Brevik and Toverud [Phys. Rev. D {\\bf 51}, 691 (1995)], is that the radius {\\it a} of the string is assumed finite, thus necessitating Neumann functions to be included in the fundamental modes. We find that the theory is changed significantly: W is now strongly concentrated in the lowest mode $(m,s)=(0,1)$, whereas the proportionality $W \\propto (G\\mu /t)^2$ that is characteristic for zero-width strings is found in the next mode (1,1). Here G is the gravitational constant, $\\mu$ the string mass per unit length, and t the GUT time.
Melt dumping in string stabilized ribbon growth
Sachs, Emanuel M. (42 Old Middlesex Rd., Belmont, MA 02178)
1986-12-09T23:59:59.000Z
A method and apparatus for stabilizing the edge positions of a ribbon drawn from a melt includes the use of wettable strings drawn in parallel up through the melt surface, the ribbon being grown between the strings. A furnace and various features of the crucible used therein permit continuous automatic growth of flat ribbons without close temperature control or the need for visual inspection.
Quantization of Minimal Strings: a Mechanical Analog
Gomez, Cesar; Montanez, Sergio; Resco, Pedro [Instituto de Fisica Teorica CSIC/UAM, C-XVI Universidad Autonoma, E-28049 Madrid (Spain)
2006-06-19T23:59:59.000Z
Recent progress in the study of Liouville field theory opens the possibility to address some problems of quantum gravity using minimal strings as a theoretical laboratory. We present a procedure to embed the minimal string target space into the phase space of an associated mechanical system. By this map quantum effects on the target space correspond to quantum corrections on the mechanical model.
Vibration monitoring system for drill string
Wassell, M.E.
1993-07-13T23:59:59.000Z
A vibration monitoring system is described for use in monitoring lateral and torsional vibrations in a drill string comprising: a drill string component having an outer surface; first accelerometer means A[sub 1] for measuring tangential acceleration; second accelerometer means A[sub 2] for measuring tangential acceleration; third accelerometer means A[sub 3] for measuring tangential acceleration; said first, second and third accelerometer means A[sub 1], A[sub 2] and A[sub 3] being mounted in said drill string component and being spaced from one another to measure acceleration forces on said drill string component tangentially with respect to the outer surface of said component wherein said first, second and third accelerometer means are adapted to measure and distinguish between lateral and torsional vibrations exerted on said drill string component.
Wiggly cosmic strings accrete dark energy
Pedro F. Gonzalez-Diaz; Jose A. Jimenez Madrid
2005-06-29T23:59:59.000Z
This paper deals with a study of the cylindrically symmetric accretion of dark energy with equation of state $p=w\\rho$ onto wiggly straight cosmic strings. We have obtained that when $w>-1$ the linear energy density in the string core gradually increases tending to a finite maximum value as time increases for all considered dark energy models. On the regime where the dominant energy condition is violated all such models predict a steady decreasing of the linear energy density of the cosmic strings as phantom energy is being accreted. The final state of the string after such an accretion process is a wiggleless defect. It is argued however that if accreation of phantom energy would proceed by successive quantum steps then the defect would continue losing linear energy density until a minimum nonzero value which can be quite smaller than that corresponding to the unperturbed string.
Electric Magnetic Duality in String Theory
Ashoke Sen
1992-10-06T23:59:59.000Z
The electric-magnetic duality transformation in four dimensional heterotic string theory discussed by Shapere, Trivedi and Wilczek is shown to be an exact symmetry of the equations of motion of low energy effective field theory even after including the scalar and the vector fields, arising due to compactification, in the effective field theory. Using this duality transformation we construct rotating black hole solutions in the effective field theory carrying both, electric and magnetic charges. The spectrum of extremal magnetically charged black holes turns out to be similar to that of electrically charged elementary string excitations. We also discuss the possibility that the duality symmetry is an exact symmetry of the full string theory under which electrically charged elementary string excitations get exchanged with magnetically charged soliton like solutions. This proposal might be made concrete following the suggestion of Dabholkar et. al. that fundamental strings may be regarded as soliton like classical solutions in the effective field theory.
Biomedical Retrieval: How Can a Thesaurus Help?
Kamps, Jaap
Biomedical Retrieval: How Can a Thesaurus Help? Leonie IJzereef1 , Jaap Kamps1,2 , and Maarten de in terminology might result in low recall scores. We study the role of a thesaurus in the biomedical information, we propose a method for exploiting the MeSH thesaurus to improve retrieval effectiveness and, more
Classification aided analysis of oscillatory signatures in controlled retrieval
Curran, Tim
retrieved or suppressed. A logistic regression based on classifier output determined that retrieval-learned material has shown the reverse rela- tionship, such that successful suppression of retrieval leads to dimin
Global longterm passive microwave satellitebased retrievals of vegetation optical depth
Evans, Jason
Global longterm passive microwave satellitebased retrievals of vegetation optical depth Yi Y. Liu,1 optical depth (VOD) retrievals from three satellitebased passive microwave instruments were merged longterm passive microwave satellitebased retrievals of vegetation optical depth, Geophys. Res. Lett., 38
A Geographic Information Retrieval Approach to Locate Pharmacies on Duty
Rosso, Paolo
Geographic Information Retrieval (GIR), Geographic Information Systems (GIS), Toponym Disambiguation 1 disciplines, in particular geographic information retrieval and geographical information systems, which playedGIRPharma: A Geographic Information Retrieval Approach to Locate Pharmacies on Duty Francisco M
Anomaly of Tensionless String in Light-cone Gauge
Kenta Murase
2015-03-04T23:59:59.000Z
The classical tensionless string theory has the spacetime conformal symmetry. We expect and require that the quantum tensionless string theory has it too. In the BRST quantization method, the theory has no spacetime conformal anomaly in two dimensions. On the other hand, in the light-cone gauge quantization without the mode expansion, the theory in $D>3$ has the spacetime conformal anomaly in the traceless part of $[\\mathcal{J}^{-I}, \\mathcal{K}^{J}]$ in some operator order. In this paper, we consider a tensionless closed bosonic string in the light-cone gauge and investigate the spacetime conformal anomaly in the theory with the mode expansion. The appearance of the spacetime conformal anomaly in the light-cone gauge is different between the case of $D>3$ and the case of $D=3$ and depends on the choice of the operator order. Therefore we must consider dangerous commutators in the spacetime conformal symmetry of $D>3$ and $D=3$ in each operator order separately. Specifically we calculate dangerous commutators, $[\\mathcal{J}^{-I},\\mathcal{K}^{K}]$ in $D>3$ and $\\tilde{\\mathcal{K}}^{-}\\equiv -i[\\mathcal{J}^{-}, \\tilde{\\mathcal{K}}^{-}]$ and $[\\mathcal{J}^{-}, \\tilde{\\mathcal{K}}^{-}]$ in $D=3$, in two types of the operator order.
An approach to interactive retrieval in face image databases based on semantic attributes
Gudivada, V.N. [Ohio Univ., Athens, OH (United States); Raghavan, V.V.; Seetharaman, G.S. [Univ. of Southwestern Louisiana, Lafayette, LA (United States)
1994-12-31T23:59:59.000Z
Image Retrieval (IR) problem is concerned with retrieving images that are relevant to users` requests from a large collection of images, referred to as the image database. A taxonomy for and the limitations of the existing approaches for image retrieval are discussed. Also, to alleviate some of the problems associated with these approaches, a unified framework for retrieval in image databases for a class of application areas is proposed. The framework provides a taxonomy for image attributes and identifies four generic types of retrieval based on the attribute taxonomy. Semantic attributes play a central role in supporting one of those generic retrieval types, referred to as Retrieval by Semantic Attributes (RSA). Semantic attributes are those attributes the specification of which necessarily involves some subjectivity, imprecision, and/or uncertainty. In this paper, we introduce Personal Construct Theory (PCT) as a knowledge elicitation tool for systematically deriving semantic attributes to support RSA in image retrieval applications. As a case study, we use a prototype database system comprising of human face images. The knowledge elicited from the face images is stored in a matrix form which is referred to as repertory grid. We propose an algorithm for RSA based on the repertory grid. The algorithm incorporates user relevance judgments as a means to deal with the inherent problems associated with the specification of semantic attributes. The algorithm incorporates user relevance judgments as a means to deal with the inherent problems associated with the specification of semantic attributes. The algorithm is implemented and tested on the human face image database and the initial results are encouraging. In essence, we have developed an overall methodology/test bed to facilitate experimentation with different algorithms for RSA.
Highly Retrievable Spinwave-Photon Entanglement Source
Sheng-Jun Yang; Xu-Jie Wang; Jun Li; Jun Rui; Xiao-Hui Bao; Jian-Wei Pan
2015-05-03T23:59:59.000Z
Entanglement between a single photon and a quantum memory forms the building blocks for quantum repeater and quantum network. Previous entanglement sources are typically with low retrieval efficiency, which limits future larger-scale applications. Here, we report a source of highly retrievable spinwave-photon entanglement. Polarization entanglement is created through interaction of a single photon with ensemble of atoms inside a low-finesse ring cavity. The cavity is engineered to be resonant for dual spinwave modes, which thus enables efficient retrieval of the spinwave qubit. An intrinsic retrieval efficiency up to 76(4)% has been observed. Such a highly retrievable atom-photon entanglement source will be very useful in future larger-scale quantum repeater and quantum network applications.
Records Management Procedures for Storage, Transfer and Retrieval...
Procedures for Storage, Transfer and Retrieval of Records from WNRC Records Management Procedures for Storage, Transfer and Retrieval of Records from WNRC Develop and maintain a...
Innovative Idaho Site Crews Find Ways to Make Waste Retrieval...
based on a careful balance of safety, compliance, and production. With a focus on continuous improvement, AMWTP's retrieval crews have retrieved the waste safely and...
Excitation Fields in a Superconducting Global String
J. R. Morris
1995-09-28T23:59:59.000Z
A model of a straight superconducting global cosmic string is examined in a setting wherein the string supports a charge/current pulse described by a travelling wave along the string. Linearized field equations are obtained for fluctuations of the scalar and vector fields of the theory, and a set of approximate particular solutions are found for the case in which the linear charge density and the current of the string have equal magnitudes. Although the equations of motion seem to suggest that the scalar and vector excitation fields are massive inside the string core, the particular solutions show that they behave as effectively massless fields which propagate at the speed of light along the string along with the primary charge/current pulse. The effect of the mass parameter is to modulate the radial profile of the excitation fields. The vector excitation field generates radial and angular components for both the electric and magnetic fields, but the particular solutions do not describe the emission or absorption of electromagnetic radiation from the string.
Effects of Overlapping Strings in pp Collisions
Christian Bierlich; Gösta Gustafson; Leif Lönnblad; Andrey Tarasov
2015-02-13T23:59:59.000Z
In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes". Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA 8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.
Effects of overlapping strings in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bierlich, Christian [Lund University; Gustafson, Gösta [Lund University; Lönnblad, Leif [Lund University; Tarasov, Andrey [JLAB
2015-03-01T23:59:59.000Z
In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possible effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.
Effects of overlapping strings in pp collisions
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Bierlich, Christian; Gustafson, Gösta; Lönnblad, Leif; Tarasov, Andrey
2015-03-01T23:59:59.000Z
In models for hadron collisions based on string hadronization, the strings are usually treated as independent, allowing no interaction between the confined colour fields. In studies of nucleus collisions it has been suggested that strings close in space can fuse to form "colour ropes." Such ropes are expected to give more strange particles and baryons, which also has been suggested as a signal for plasma formation. Overlapping strings can also be expected in pp collisions, where usually no phase transition is expected. In particular at the high LHC energies the expected density of strings is quite high. To investigate possiblemore »effects of rope formation, we present a model in which strings are allowed to combine into higher multiplets, giving rise to increased production of baryons and strangeness, or recombine into singlet structures and vanish. Also a crude model for strings recombining into junction structures is considered, again giving rise to increased baryon production. The models are implemented in the DIPSY MC event generator, using PYTHIA8 for hadronization, and comparison to pp minimum bias data, reveals improvement in the description of identified particle spectra.« less
Strings and their compactification from the particle viewpoint
Slansky, R.
1986-01-01T23:59:59.000Z
A series of four lectures is given which deals with the particle formulation of string theory. An introductory lecture is given on where the idea of strings comes from and what strings are. An introduction is given to simple Lie algebras and their representations. Compactified strings and the heterotic theories are discussed, showing how infinite-dimensional Kac-Moody affine algebras can be spectrum generating algebras in (open) string theories. The spectrum of excited states of the heterotic string is examined, and comments are made on representations of affine algebras. Some aspects are shown of the algebraic structure of compactified closed bosonic strings. (LEW)
SU(4) pure-gauge string tensions
Shigemi Ohta; Matthew Wingate
1998-08-19T23:59:59.000Z
In response to recently renewed interests in SU(N) pure-gauge dynamics with large N, both from M/string duality and from finite-temperature QCD phase structure, we calculate string tensions acting between the fundamental 4, diquark 6 and other color charges in SU(4) pure-gauge theory at temperatures below the deconfining phase change and above the bulk phase transition. Our results suggest 4 and 6 representations have different string tensions, with a ratio of about 1.3. We also found the deconfining phase change is not strong.
Phenomenology of heterotic and type II orientifold string models
Mayes, Van Eric
2009-05-15T23:59:59.000Z
= ecL; (2.2) 15 In particular, this results in the 10 containing a neutral component with the quantum numbers of ?cL. Spontaneous GUT symmetry breaking can be achieved by using a 10 and ?10 of superheavy Higgs where the neutral components develop a... . . . . . . . . . . . . . . . . . . . . 20 D. The Decays of the Lightest SU(4) Mesons . . . . . . . . . . 22 E. The Fate of the Neutral Tetrons . . . . . . . . . . . . . . . 24 F. The Fate of the Charged Tetrons . . . . . . . . . . . . . . 26 G. Generic Super-heavy Relic Decay...
Semiclassical analysis of string-gauge duality on noncommutative space
Rashkov, R.C.; Viswanathan, K.S.; Yang Yi [Department of Physics, Sofia University, 1164 Sofia (Bulgaria); Department of Physics, Simon Fraser University, Burnaby, British Columbia (Canada); Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China)
2004-10-15T23:59:59.000Z
We use semiclassical methods to study closed strings in the modified AdS{sub 5}xS{sup 5} background with constant B fields. The pointlike closed strings and the stretched closed strings rotating around the big circle of S{sup 5} are considered. Quantization of these closed string leads to a time-dependent string spectrum, which we argue corresponds to the renormalization-group flow of the dual noncommutative Yang-Mills theory.
Fuel Retrieval System Design Verification Report
GROTH, B.D.
2000-04-11T23:59:59.000Z
The Fuel Retrieval Subproject was established as part of the Spent Nuclear Fuel Project (SNF Project) to retrieve and repackage the SNF located in the K Basins. The Fuel Retrieval System (FRS) construction work is complete in the KW Basin, and start-up testing is underway. Design modifications and construction planning are also underway for the KE Basin. An independent review of the design verification process as applied to the K Basin projects was initiated in support of preparation for the SNF Project operational readiness review (ORR). A Design Verification Status Questionnaire, Table 1, is included which addresses Corrective Action SNF-EG-MA-EG-20000060, Item No.9 (Miller 2000).
Mining Energy from a Black Hole by Strings
V. Frolov; D. Fursaev
2001-05-10T23:59:59.000Z
We discuss how cosmic strings can be used to mine energy from black holes. A string attached to the black hole gives rise to an additional channel for the energy release. It is demonstrated that when a string crosses the event horizon, its transverse degrees of freedom are thermally excited and thermal string perturbations propagate along the string to infinity. The internal metric induced on the 2D worldsheet of the static string crossing the horizon describes a 2D black hole. For this reason thermal radiation of string excitations propagating along the string can be interpreted as Hawking radiation of the 2D black hole. It is shown that the rate of energy emission through the string channel is of the same order of magnitude as the bulk radiation of the black hole. Thus, for N strings attached to the black hole the efficiency of string channels is increased by factor N. We discuss restrictions on N which exist because of the finite thickness of strings, the gravitational backreaction and quantum fluctuations. Our conclusion is that the energy emission rate by strings can be increased as compared to the standard emission in the bulk by the factor 10^3 for GUT strings and up to the factor 10^{31} for electroweak strings.
The Three-String Vertex for a Plane-Wave Background
John H. Schwarz
2003-12-23T23:59:59.000Z
The three string vertex for Type IIB superstrings in a maximally supersymmetric plane-wave background can be constructed in a light-cone gauge string field theory formalism. The detailed formula contains certain Neumann coefficients, which are functions of a momentum fraction y and a mass parameter \\mu. This paper reviews the derivation of useful explicit expressions for these Neumann coefficients generalizing flat-space (\\mu = 0) results obtained long ago. These expressions are then used to explore the large \\mu asymptotic behavior, which is required for comparison with dual perturbative gauge theory results. The asymptotic formulas, exact up to exponentially small corrections, turn out to be surprisingly simple.
Multifarious Assembly Mixtures: Systems Allowing Retrieval of Diverse Stored Structures
Arvind Murugan; Zorana Zeravcic; Michael P. Brenner; Stanislas Leibler
2014-08-29T23:59:59.000Z
Self-assembly materials are traditionally designed so that molecular or meso-scale components form a single kind of large structure. Here, we propose a scheme to create "multifarious assembly mixtures", which self-assemble many different large structures from a set of shared components. We show that the number of multifarious structures stored in the solution of components increases rapidly with the number of different types of components. Yet, each stored structure can be retrieved by tuning only a few parameters, the number of which is only weakly dependent on the size of the assembled structure. Implications for artificial and biological self-assembly are discussed.
String field theory and tachyon dynamics
Yang, Haitang, Ph. D. Massachusetts Institute of Technology
2006-01-01T23:59:59.000Z
In this thesis we present some works done during my doctoral studies. These results focus on two directions. The first one is motivated by tachyon dynamics in open string theory. We calculate the stress tensors for the ...
Two-dimensional QCD and strings
D. J. Gross; W. Taylor
1993-11-12T23:59:59.000Z
A review is given of recent research on two-dimensional gauge theories, with particular emphasis on the equivalence between these theories and certain string theories with a two-dimensional target space. Some related open problems are discussed.
Axions from cosmic string and wall decay
Hagmann, C A
2010-03-10T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall} {approx} 1-100 (f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Axions from cosmic string and wall decay
Hagmann, Chris [Lawrence Livermore National Laboratory, L-59, 7000 East Ave, Livermore, CA (United States)
2010-08-30T23:59:59.000Z
If inflation occurred with a reheat temperature > T{sub PQ}, axions from the decay of global axion strings and domain walls would make an important contribution to the cosmological energy density, comparable to that from vacuum misalignment. Several groups have numerically studied the evolution of axion strings and walls in the past, however substantial uncertainties remain in their contribution to the present density {Omega}{sub a,string+wall{approx}}1-100(f{sub a}/10{sup 12} GeV){sup 7/6}, where f{sub a} is the axion decay constant. I will describe the numerical methods used in our simulations and show results for several string and wall configurations.
Introduction to string and superstring theory II
Peskin, M.E.
1987-03-01T23:59:59.000Z
Conformal field theory is reviewed, then conformal invariance is used to rederive the basic results on the embedding dimensionality for bosonic and fermionic strings. The spectrum of the bosonic and the computation of scattering amplitudes are discussed. The formalism used is extended to clarify the origin of Yang-Mills gauge invariance in the open bosonic string theory. The question of the general-coordinate gauge invariance of string theory is addressed, presenting two disparate viewpoints on this question. A brief introduction is then given of the reduction from the idealized string theory in 10 extended dimensions to more realistic solutions in which all but 4 of these dimensions are compactified. The state of knowledge about the space-time supersymmetry of the superstring from the covariant viewpoint is outlined. An approach for identifying possible 6-dimensional spaces which might represent the form of the compact dimensions is discussed, and the orbifold scheme of compactification is presented. 77 refs., 18 figs. (LEW)
Compressed Indexes for Approximate String Matching
Sung, Wing-Kin Ken"
Compressed Indexes for Approximate String Matching Ho-Leung Chan1 Tak-Wah Lam1, Wing-Kin Sung2 Siu the index space to O(n log n). Huynh et al. [10] and Lam et al. [11] further compressed the index to O,wongss}@comp.nus.edu.sg Abstract. We revisit the problem of indexing a string S[1..n] to support searching all substrings
Cosmological Constant and Axions in String Theory
Svrcek, Peter; /Stanford U., Phys. Dept. /SLAC
2006-08-18T23:59:59.000Z
String theory axions appear to be promising candidates for explaining cosmological constant via quintessence. In this paper, we study conditions on the string compactifications under which axion quintessence can happen. For sufficiently large number of axions, cosmological constant can be accounted for as the potential energy of axions that have not yet relaxed to their minima. In compactifications that incorporate unified models of particle physics, the height of the axion potential can naturally fall close to the observed value of cosmological constant.
HTI retrieval demonstration project execution plan
Ellingson, D.R.
1997-09-04T23:59:59.000Z
This plan describes the process for demonstrating the retrieval of difficult Hanford tank waste forms utilizing commercial technologies and the private sector to conduct the operations. The demonstration is to be conducted in Tank 241-C-106.
Technical requirements specification for tank waste retrieval
Lamberd, D.L.
1996-09-26T23:59:59.000Z
This document provides the technical requirements specification for the retrieval of waste from the underground storage tanks at the Hanford Site. All activities covered by this scope are conducted in support of the Tank Waste Remediation System (TWRS) mission.
Aerosol Retrieval Using Remote-sensed Observations
Wang, Yueqing
2012-01-01T23:59:59.000Z
1.2 Aerosols Impacts on HumanBayesian Approach for Aerosol Retrieval Using MISR Data 2.1for Including a Richer Variety of Aerosol Compositions . 2.5
Fuel Retrieval System (FRS) Design Verification
YANOCHKO, R.M.
2000-01-27T23:59:59.000Z
This document was prepared as part of an independent review to explain design verification activities already completed, and to define the remaining design verification actions for the Fuel Retrieval System. The Fuel Retrieval Subproject was established as part of the Spent Nuclear Fuel Project (SNF Project) to retrieve and repackage the SNF located in the K Basins. The Fuel Retrieval System (FRS) construction work is complete in the KW Basin, and start-up testing is underway Design modifications and construction planning are also underway for the KE Basin. An independent review of the design verification process as applied to the K Basin projects was initiated in support of preparation for the SNF Project operational readiness review (ORR).
Speeding up Ozone Profile Retrieval using Machine Learning Techniques
Emmerich, Michael
Speeding up Ozone Profile Retrieval using Machine Learning Techniques L.M. Strijbosch April 25 to the process of ozone profile retrieval, a method for retrieving a global ozone distribution from satellite Machines are selected to replace the forward model, which is the slowest part of ozone profile retrieval
Successful Approaches in the TREC Video Retrieval Evaluations
Fan, Jianping
Terms Experimentation. Keywords Video retrieval, search, TRECVID, information retrieval benchmarks. 1 over the last three years. The task involves the search and retrieval of shots from MPEG digitized retrieval technologies. The search evaluations are grouped into interactive (with a human in the loop
GeoVSM: An Integrated Retrieval Model For Geographical Information
Klippel, Alexander
maps, images, and texts. Effective retrieval systems for geographical information are currently studied retrieval (IR) systems in dealing with multimedia geographical information, and proposes a new retrievalGeoVSM: An Integrated Retrieval Model For Geographical Information Guoray Cai School of Information
CLOUD CLASSIFICATION AND CLOUD PROPERTY RETRIEVAL FROM MODIS , W. Paul Menzel
Li, Jun
6.4 CLOUD CLASSIFICATION AND CLOUD PROPERTY RETRIEVAL FROM MODIS AND AIRS Jun Li * , W. Paul Menzel Observing System's (EOS) Aqua satellite enable global monitoring of the distribution of clouds. The MODIS is able to provide at high spatial resolution (1 ~ 5km) a cloud mask, surface and cloud types, cloud phase
Methods for heel retrieval for tanks C-101, C-102, and C-111 at the Hanford Site
Sams, Terry L. [Washington River Protection Solutions, LLC, Richland, WA (United States); Kirch, N. W. [Washington River Protection Solutions, LLC, Richland, WA (United States); Reynolds, Jacob G. [Washington River Protection Solutions, LLC, Richland, WA (United States)
2013-01-11T23:59:59.000Z
The purpose of this paper is to evaluate the prospects of using bulk waste characteristics to determine the most appropriate heel retrieval technology. If the properties of hard to remove heels can be determined before bulk retrieval, then a heel retrieval technology can be selected before bulk retrieval is complete. This would save substantially on sampling costs and would allow the deployment of the heel retrieval technology immediately after bulk retrieval. The latter would also accelerate the heel removal schedule. A number of C-farm retrievals have been fully or partially completed at the time of this writing. Thus, there is already substantial information on the success of different technologies and the composition of the heels. There is also substantial information on the waste types in each tank based on historical records. Therefore, this study will correlate the performance of technologies used so far and compare them to the known waste types in the tanks. This will be used to estimate the performance of future C Farm heel retrievals. An initial decision tree is developed and employed on tanks C-101, C-102, and C 111. An assumption of this study is that no additional characterization information would be available, before or after retrieval. Note that collecting additional information would substantially increase the probability of success. Deploying some in-situ testing technologies, such as a water lance or an in-situ Raman probe, might substantially increase the probability of successfully selecting the process conditions without having to take samples from the tanks for laboratory analysis.
Methods for Heel Retrieval for Tanks C-101, C-102, and C-111 at the Hanford Site - 13064
Sams, T.L.; Kirch, N.W.; Reynolds, J.H. [Washington River protection Solutions, Richland, WA 99352 (United States)] [Washington River protection Solutions, Richland, WA 99352 (United States)
2013-07-01T23:59:59.000Z
The purpose of this paper is to evaluate the prospects of using bulk waste characteristics to determine the most appropriate heel retrieval technology. If the properties of hard to remove heels can be determined before bulk retrieval, then a heel retrieval technology can be selected before bulk retrieval is complete. This would save substantially on sampling costs and would allow the deployment of the heel retrieval technology immediately after bulk retrieval. The latter would also accelerate the heel removal schedule. A number of C-farm retrievals have been fully or partially completed at the time of this writing. Thus, there is already substantial information on the success of different technologies and the composition of the heels. There is also substantial information on the waste types in each tank based on historical records. Therefore, this study will correlate the performance of technologies used so far and compare them to the known waste types in the tanks. This will be used to estimate the performance of future C Farm heel retrievals. An initial decision tree is developed and employed on tanks C-101, C-102, and C 111. An assumption of this study is that no additional characterization information would be available, before or after retrieval. Note that collecting additional information would substantially increase the probability of success. Deploying some in-situ testing technologies, such as a water lance or an in-situ Raman probe, might substantially increase the probability of successfully selecting the process conditions without having to take samples from the tanks for laboratory analysis. (authors)
Full-scale retrieval of simulated buried transuranic waste
Valentich, D.J. [EG and G Idaho, Inc., Idaho Falls, ID (United States)
1993-09-01T23:59:59.000Z
This report describes the results of a field test conducted to determine the effectiveness of using conventional type construction equipment for the retrieval of buried transuranic (TRU) waste. A cold (nonhazardous and nonradioactive) test pit (1,100 yd{sup 3} volume) was constructed with boxes and drums filled with simulated waste materials, such as metal, plastic, wood, concrete, and sludge. Large objects, including truck beds, tanks, vaults, pipes, and beams, were also placed in the pit. These materials were intended to simulate the type of wastes found in TRU buried waste pits and trenches. A series of commercially available equipment items, such as excavators and tracked loaders outfitted with different end effectors, were used to remove the simulated waste. Work was performed from both the abovegrade and belowgrade positions. During the demonstration, a number of observations, measurements, and analyses were performed to determine which equipment was the most effective in removing the waste. The retrieval rates for the various excavation techniques were recorded. The inherent dust control capabilities of the excavation methods used were observed. The feasibility of teleoperating reading equipment was also addressed.
Complex Retrieval of Embedded IVC Filters: Alternative Techniques and Histologic Tissue Analysis
Kuo, William T., E-mail: wkuo@stanford.edu [Stanford University Medical Center, Division of Vascular and Interventional Radiology, Department of Radiology (United States); Cupp, John S. [Stanford University Medical Center, Department of Pathology (United States); Louie, John D.; Kothary, Nishita; Hofmann, Lawrence V.; Sze, Daniel Y.; Hovsepian, David M. [Stanford University Medical Center, Division of Vascular and Interventional Radiology, Department of Radiology (United States)
2012-06-15T23:59:59.000Z
Purpose: We evaluated the safety and effectiveness of alternative endovascular methods to retrieve embedded optional and permanent filters in order to manage or reduce risk of long-term complications from implantation. Histologic tissue analysis was performed to elucidate the pathologic effects of chronic filter implantation. Methods: We studied the safety and effectiveness of alternative endovascular methods for removing embedded inferior vena cava (IVC) filters in 10 consecutive patients over 12 months. Indications for retrieval were symptomatic chronic IVC occlusion, caval and aortic perforation, and/or acute PE (pulmonary embolism) from filter-related thrombus. Retrieval was also performed to reduce risk of complications from long-term filter implantation and to eliminate the need for lifelong anticoagulation. All retrieved specimens were sent for histologic analysis. Results: Retrieval was successful in all 10 patients. Filter types and implantation times were as follows: one Venatech (1,495 days), one Simon-Nitinol (1,485 days), one Optease (300 days), one G2 (416 days), five Guenther-Tulip (GTF; mean 606 days, range 154-1,010 days), and one Celect (124 days). There were no procedural complications or adverse events at a mean follow-up of 304 days after removal (range 196-529 days). Histology revealed scant native intima surrounded by a predominance of neointimal hyperplasia and dense fibrosis in all specimens. Histologic evidence of photothermal tissue ablation was confirmed in three laser-treated specimens. Conclusion: Complex retrieval methods can now be used in select patients to safely remove embedded optional and permanent IVC filters previously considered irretrievable. Neointimal hyperplasia and dense fibrosis are the major components that must be separated to achieve successful retrieval of chronic filter implants.
Decision analysis for mobilizing and retrieving sludge from double-shell tanks
Brothers, A.J.; Williams, N.C.; Dukelow, J.S.; Hansen, R.I. [and others] [and others
1997-09-01T23:59:59.000Z
This decision analysis evaluates alternative technologies for the initial mobilization and retrieval of sludges in double-shell tanks (DSTs). The analysis is from the perspective of the need to move sludges from one DST to another for interim retrieval. It supports the more general decision of which technologies to use to retreive various types of DST waste. The initial analysis is from the perspective of a typical DST with 2 ft of sludge to mobilize. During the course of the analysis, it became clear that it was important to also consider sludge mobilization in support of the high-level waste (HLW) vitrification demonstration plant, and in particular the risks associated with failing to meeting the minimum order requirements for the vendor, as well as the cost of mobilization and retrieval from the HLW vitrification source tanks.
Storage capacity and retrieval time of small-world neural networks
Oshima, Hiraku; Odagaki, Takashi [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan)
2007-09-15T23:59:59.000Z
To understand the influence of structure on the function of neural networks, we study the storage capacity and the retrieval time of Hopfield-type neural networks for four network structures: regular, small world, random networks generated by the Watts-Strogatz (WS) model, and the same network as the neural network of the nematode Caenorhabditis elegans. Using computer simulations, we find that (1) as the randomness of network is increased, its storage capacity is enhanced; (2) the retrieval time of WS networks does not depend on the network structure, but the retrieval time of C. elegans's neural network is longer than that of WS networks; (3) the storage capacity of the C. elegans network is smaller than that of networks generated by the WS model, though the neural network of C. elegans is considered to be a small-world network.
String Theory and Math: Why This Marriage May Last
Aganagic, Mina
2015-01-01T23:59:59.000Z
String theory is changing the relationship between mathematics and physics. The central role is played by the phenomenon of duality, which is intrinsic to quantum physics and abundant in string theory.
On the solutions to the string equation
A. Schwarz
1991-09-10T23:59:59.000Z
The set of solutions to the string equation $[P,Q]=1$ where $P$ and $Q$ are differential operators is described.It is shown that there exists one-to-one correspondence between this set and the set of pairs of commuting differential operators.This fact permits us to describe the set of solutions to the string equation in terms of moduli spa- ces of algebraic curves,however the direct description is much simpler. Some results are obtained for the superanalog to the string equation where $P$ and $Q$ are considered as superdifferential operators. It is proved that this equation is invariant with respect to Manin-Radul, Mulase-Rabin and Kac-van de Leur KP-hierarchies.
Low Tension Strings on a Cosmological Singularity
Ben Craps; Chethan Krishnan; Ayush Saurabh
2014-09-21T23:59:59.000Z
It has recently been argued that the singularity of the Milne orbifold can be resolved in higher spin theories. In string theory scattering amplitudes, however, the Milne singularity gives rise to ultraviolet divergences that signal uncontrolled backreaction. Since string theory in the low tension limit is expected to be a higher spin theory (although precise proposals only exist in special cases), we investigate what happens to these scattering amplitudes in the low tension limit. We point out that the known problematic ultraviolet divergences disappear in this limit. In addition we systematically identify all divergences of the simplest 2-to-2 string scattering amplitude on the Milne orbifold, and argue that the divergences that survive in the low tension limit have sensible infrared interpretations.
Storage and Retrieval of a Squeezed Vacuum
Kazuhito Honda; Daisuke Akamatsu; Manabu Arikawa; Yoshihiko Yokoi; Keiichirou Akiba; Satoshi Nagatsuka; Takahito Tanimura; Akira Furusawa; Mikio Kozuma
2008-01-27T23:59:59.000Z
Storage and retrieval of a squeezed vacuum was successfully demonstrated using electromagnetically induced transparency. 930ns of the squeezed vacuum pulse was incident on the laser cooled 87Rb atoms with an intense control light in a coherent state. When the squeezed vacuum pulse was slowed and spatially compressed in the cold atoms, the control light was switched off. After 3us of storage, the control light was switched on again and the squeezed vacuum was retrieved, as was confirmed using the time-domain homodyne method.
String Theory clues for the low-$\\ell$ CMB ?
N. Kitazawa; A. Sagnotti
2014-12-01T23:59:59.000Z
"Brane Supersymmetry Breaking" is a peculiar string-scale mechanism that can unpair Bose and Fermi excitations in orientifold models. It results from the simultaneous presence, in the vacuum, of collections of D-branes and orientifolds that are not mutually BPS, and is closely tied to the scale of string excitations. It also leaves behind, for a mixing of dilaton and internal breathing mode, an exponential potential that is just too steep for a scalar to emerge from the initial singularity while descending it. As a result, in this class of models the scalar can generically bounce off the exponential wall, and this dynamics brings along, in the power spectrum, an infrared depression typically followed by a pre-inflationary peak. We elaborate on a possible link between this type of bounce and the low-$\\ell$ end of the CMB angular power spectrum. For the first 32 multipoles, one can reach a 50 % reduction in $\\chi^{\\,2}$ with respect to the standard $\\Lambda$CDM setting.
Electron string ion sources for carbon ion cancer therapy accelerators
Boytsov, A Yu; Donets, E D; Donets, E E; Katagiri, K; Noda, K; Ponkin, D O; Ramzdorf, A Yu; Salnikov, V V; Shutov, V B
2015-01-01T23:59:59.000Z
The Electron String type of Ion Sources (ESIS) was developed, constructed and tested first in the Joint Institute for Nuclear Research. These ion sources can be the appropriate sources for production of pulsed C4+ and C6+ ion beams which can be used for cancer therapy accelerators. In fact the test ESIS Krion-6T already now at the solenoid magnetic field only 4.6 T provides more than 10^10 C4+ ions per pulse and about 5*10^9 C6+ ions per pulse. Such ion sources could be suitable for application at synchrotrons. It was also found, that Krion-6T can provide more than 10^11 C6+ ions per second at 100 Hz repetition rate, and the repetition rate can be increased at the same or larger ion output per second. This makes ESIS applicable at cyclotrons as well. As for production of 11C radioactive ion beams ESIS can be the most economic kind of ion source. To proof that the special cryogenic cell for pulse injection of gaseous species into electron string was successfully tested using the ESIS Krion-2M.
Closed strings from decaying D-branes
Neil Lambert; Hong Liu; Juan Maldacena
2007-02-05T23:59:59.000Z
We compute the emission of closed string radiation from homogeneous rolling tachyons. For an unstable decaying D$p$-brane the radiated energy is infinite to leading order for $p\\leq 2$ and finite for $p>2$. The closed string state produced by a decaying brane is closely related to the state produced by D-instantons at a critical Euclidean distance from $t=0$. In the case of a D0 brane one can cutoff this divergence so that we get a finite energy final state which would be the state that the brane decays into.
Perturbative diagrams in string field theory
Washington Taylor
2002-07-13T23:59:59.000Z
A general algorithm is presented which gives a closed-form expression for an arbitrary perturbative diagram of cubic string field theory at any loop order. For any diagram, the resulting expression is given by an integral of a function of several infinite matrices, each built from a finite number of blocks containing the Neumann coefficients of Witten's 3-string vertex. The closed-form expression for any diagram can be approximated by level truncation on oscillator level, giving a computation involving finite size matrices. Some simple tree and loop diagrams are worked out as examples of this approach.
Perturbative computations in string field theory
Washington Taylor
2004-04-15T23:59:59.000Z
These notes describe how perturbative on-shell and off-shell string amplitudes can be computed using string field theory. Computational methods for approximating arbitrary amplitudes are discussed, and compared with standard world-sheet methods for computing on-shell amplitudes. These lecture notes are not self-contained; they contain the material from W. Taylor's TASI 2003 lectures not covered in the recently published ``TASI 2001'' notes {\\tt hep-th/0311017} by Taylor and Zwiebach, and should be read as a supplement to those notes.
Parallel ion strings in linear multipole traps
Mathieu Marciante; Caroline Champenois; J. Pedregosa-Gutierrez; Annette Calisti; Martina Knoop
2011-03-13T23:59:59.000Z
Additional radio-frequency (rf) potentials applied to linear multipole traps create extra field nodes in the radial plane which allow one to confine single ions, or strings of ions, in totally rf field-free regions. The number of nodes depends on the order of the applied multipole potentials and their relative distance can be easily tuned by the amplitude variation of the applied voltages. Simulations using molecular dynamics show that strings of ions can be laser cooled down to the Doppler limit in all directions of space. Once cooled, organized systems can be moved with very limited heating, even if the cooling process is turned off.
Cosmic strings: A problem or a solution
Bennett, D.P.; Bouchet, F.R.
1987-10-01T23:59:59.000Z
The most fundamental issue in the theory of cosmic strings is addressed by means of Numerical Simulations: the existence of a scaling solution. The resolution of this question will determine whether cosmic strings can form the basis of an attractive theory of galaxy formation or prove to be a cosmological disaster like magnetic monopoles or domain walls. After a brief discussion of our numerical technique, results are presented which, though still preliminary, offer the best support to date of this scaling hypothesis. 6 refs., 2 figs.
Diffractive Scattering and Gauge/String Duality
Tan, Chung-I [Brown University, Providence, Rhode Island, United States
2009-09-01T23:59:59.000Z
High-energy diffractive scattering will be discussed based on Gauge/String duality. As shown by Brower, Polchinski, Strassler and Tan, the ubiquitous Pomeron emerges naturally in gauge theories with string-theoretical descriptions. Its existence is intimately tied to gluons, and also to the energy-momentum tensor. With a confining dual background metric, the Pomeron can be interpreted as a 'massive graviton'. In a single unified step, both its infrared and ultraviolet properties are dealt with, reflecting confinement and conformal symmetry respectively. An effective field theory for high-energy scattering can be constructed. Applications based on this approach will also be described.
The Early Years of String Theory: A Personal Perspective
John H. Schwarz
2009-04-03T23:59:59.000Z
This article surveys some of the highlights in the development of string theory through the first superstring revolution in 1984. The emphasis is on topics in which the author was involved, especially the observation that critical string theories provide consistent quantum theories of gravity and the proposal to use string theory to construct a unified theory of all fundamental particles and forces.
Closed string field theory in a-gauge
Masako Asano; Mitsuhiro Kato
2012-09-09T23:59:59.000Z
We show that a-gauge, a class of covariant gauges developed for bosonic open string field theory, is consistently applied to the closed string field theory. A covariantly gauge-fixed action of massless fields can be systematically derived from a-gauge-fixed action of string field theory.
Improving ozone profile retrieval from spaceborne UV backscatter
Haak, Hein
Chapter 2 Improving ozone profile retrieval from spaceborne UV backscatter spectrometers using convergence behaviour diagnostics Abstract The Ozone Profile Algorithm (OPERA), developed at KNMI, retrieves the vertical ozone distribution from nadir spectral satellite measurements of back scattered sunlight
The Flow of Information in Information Retrieval: its modelling
Lalmas, Mounia
The Flow of Information in Information Retrieval: its modelling Mounia Lalmas Department of Computing Science University of Glasgow Situation Theory for Information Retrieval Information is and intuitively acceptable definition of information; until now, none of these have succeeded. Authors
The Moduli Space and M(atrix) Theory of 9d N=1 Backgrounds of M/String Theory
Ofer Aharony; Zohar Komargodski; Assaf Patir
2007-05-22T23:59:59.000Z
We discuss the moduli space of nine dimensional N=1 supersymmetric compactifications of M theory / string theory with reduced rank (rank 10 or rank 2), exhibiting how all the different theories (including M theory compactified on a Klein bottle and on a Mobius strip, the Dabholkar-Park background, CHL strings and asymmetric orbifolds of type II strings on a circle) fit together, and what are the weakly coupled descriptions in different regions of the moduli space. We argue that there are two disconnected components in the moduli space of theories with rank 2. We analyze in detail the limits of the M theory compactifications on a Klein bottle and on a Mobius strip which naively give type IIA string theory with an uncharged orientifold 8-plane carrying discrete RR flux. In order to consistently describe these limits we conjecture that this orientifold non-perturbatively splits into a D8-brane and an orientifold plane of charge (-1) which sits at infinite coupling. We construct the M(atrix) theory for M theory on a Klein bottle (and the theories related to it), which is given by a 2+1 dimensional gauge theory with a varying gauge coupling compactified on a cylinder with specific boundary conditions. We also clarify the construction of the M(atrix) theory for backgrounds of rank 18, including the heterotic string on a circle.
Web Information Retrieval Author Preprint for Web
Hawking, David
Web Information Retrieval Author Preprint for Web Nick Craswell and David Hawking 18 April 2009 1 Introduction This chapter outlines some distinctive characteristics of web information re- trieval, starting with a broad description of web data and the needs of web searching users, then working through ranking
2, 623668, 2002 Retrieval methods of
Boyer, Edmond
to errors in the retrieval of column densities and concentration profiles of atmospheric trace gas species surface observations gave the highest absolute cloud fraction when compared with individual PMD sub with a constant flow of data with a high spectral resolution and a full geographical coverage in a limited amount
Evaluating Retrieval Performance using Clickthrough Data
Joachims, Thorsten
for the user. Taking an approach from experiment design, the paper proposes an experiment setup that generates feedback can provide powerful information for analyzing and optimizing the performance of information retrieval systems. Unfortunately, experience shows that users are only rarely willing to give explicit
Synchronous Collaborative Information Retrieval with Relevance Feedback
Lee, Hyowon
. A user enters a search query and the search engine Retrieval. returns a list of documents according interacting with a search engine and performing knowledge amongst co-searchers. In our system this transfer a search task, is still an individual activity. We propose an of knowledge is achieved through
An Information Calculus for Information Retrieval
Jose, Joemon M.
An Information Calculus for Information Retrieval C.J. van Rijsbergen Computing Science Department not whistle it in mathematics either' Introduction In the beginning there was information, later there was probability, and very much later there was logic. Information is and always has been an elusive concept
Iterative Algorithms for Ptychographic Phase Retrieval
Yang, Chao; Qian, Jianliang; Schirotzek, Andre; Maia, Filipe; Marchesini, Stefano
2011-05-03T23:59:59.000Z
Ptychography promises diffraction limited resolution without the need for high resolution lenses. To achieve high resolution one has to solve the phase problem for many partially overlapping frames. Here we review some of the existing methods for solving ptychographic phase retrieval problem from a numerical analysis point of view, and propose alternative methods based on numerical optimization.
Optimal Estimation Retrieval Aerosol Microphysical Properties
Oxford, University of
) the validation of this algorithm on the basis of synthetic extinction data, and (3) application of the new algorithm to SAGE II measurements of stratospheric background aerosol. The validation results indicate that the new method is able to retrieve the particle size of typical background aerosols reasonably well
Green-Schwarz superstring from type IIB matrix model
Kitazawa, Yoshihisa [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Department of Particle and Nuclear Physics, The Graduate University for Advanced Studies, Tsukuba Ibaraki 305-0801 (Japan); Nagaoka, Satoshi [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)
2008-01-15T23:59:59.000Z
We construct a Green-Schwarz (GS) light-cone closed superstring theory from the type IIB matrix model. A GS light-cone string action is derived from the two-dimensional N=8 U(n) noncommutative Yang-Mills (NCYM) theory by identifying a noncommutative scale with a string scale. The supersymmetry transformation for the light-cone gauge action is also derived from supersymmetry transformation for the IIB matrix model. By identifying the physical states and interaction vertices, string theory is perturbatively reproduced.
D-branes and string field theory
Sigalov, Ilya
2006-01-01T23:59:59.000Z
In this thesis we study the D-brane physics in the context of Witten's cubic string field theory. We compute first few terms the low energy effective action for the non-abelian gauge field A, from Witten's action. We show ...
Abelian-Higgs strings in Rastall gravity
Eugenio R. Bezerra de Mello; Julio C. Fabris; Betti Hartmann
2015-04-02T23:59:59.000Z
In this paper we analyze Abelian-Higgs strings in a phenomenological model that takes quantum effects in curved space-time into account. This model, first introduced by Rastall, cannot be derived from an action principle. We formulate phenomenological equations of motion under the guiding principle of minimal possible deformation of the standard equations. We construct string solutions that asymptote to a flat space-time with a deficit angle by solving the set of coupled non-linear ordinary differential equations numerically. Decreasing the Rastall parameter from its Einstein gravity value we find that the deficit angle of the space-time increases and becomes equal to $2\\pi$ at some critical value of this parameter that depends on the remaining couplings in the model. For smaller values the resulting solutions are supermassive string solutions possessing a singularity at a finite distance from the string core. Assuming the Higgs boson mass to be on the order of the gauge boson mass we find that also in Rastall gravity this happens only when the symmetry breaking scale is on the order of the Planck mass. We also observe that for specific values of the parameters in the model the energy per unit length becomes proportional to the winding number, i.e. the degree of the map $S^1 \\rightarrow S^1$. Unlike in the BPS limit in Einstein gravity, this is, however, not connect to an underlying mathematical structure, but rather constitutes a would-be-BPS bound.
P. S. Howe; N. D. Lambert; P. C. West
1997-09-09T23:59:59.000Z
We obtain a BPS soliton of the M theory fivebrane's equations of motion representing a supersymmetric self-dual string. The resulting solution is then dimensionally reduced and used to obtain 0-brane and (p-2)-brane solitons on D-p-branes.
Evidence for Non-perturbative String Symmetries
John H. Schwarz
1994-11-29T23:59:59.000Z
String theory appears to admit a group of discrete field transformations -- called $S$ dualities -- as exact non-perturbative quantum symmetries. Mathematically, they are rather analogous to the better-known $T$ duality symmetries, which hold perturbatively. In this talk the evidence for $S$ duality is reviewed and some speculations are presented.
An Alternative String Landscape Cosmology: Eliminating Bizarreness
Clavelli, Louis J.
An Alternative String Landscape Cosmology: Eliminating Bizarreness L. Clavelli and Gary R landscape models or whether there are scenarios in which it is avoided. If a viable alternative cosmology in mind that the alternative is not ruled out. In addition to being consistent with current observations
String inspired effective Lagrangian and Inflationary Universe
E. Abdalla; A. C. V. V. de Siqueira
1993-01-26T23:59:59.000Z
We consider a string inspired effective Lagrangian for the graviton and dilaton, containing Einstein gravity at the zero slope limit. The numerical solution of the problem shows asymptotically an inflationary universe. The time is measured by the dilaton, as one expects. The result is independent of the introduction of ad-hoc self interactions for the dilaton field.
GUEST EDITORIAL Multimedia indexing and retrieval: ever great challenges
Gabbouj, Moncef
GUEST EDITORIAL Multimedia indexing and retrieval: ever great challenges Chabane Djeraba & Moncef Abstract In this introduction, we present a brief state of the art of multimedia indexing and retrieval the next multimedia indexing and retrieval generation. The contributions explore wide range of fields
Estimating Query Difficulty for News Prediction Retrieval Nattiya Kanhabua
stories, as well as strategies planning and risk management. The aforemen- tioned work has been shown and Retrieval--Retrieval models; H.3.4 [Information Storage and Retrieval]: Systems and Software-genomic society? When can re- newable energy replace fossil fuels? These questions commonly This is a corrected
Single Database Private Information Retrieval with Logarithmic Communication
International Association for Cryptologic Research (IACR)
Single Database Private Information Retrieval with Logarithmic Communication Yan-Cheng Chang of single database private information retrieval, and present schemes with only logarithmic server database private information retrieval (1dPIR) is a cryptographic protocol between a database server, who
Single Database Private Information Retrieval with Logarithmic Communication
International Association for Cryptologic Research (IACR)
Single Database Private Information Retrieval with Logarithmic Communication YanÂCheng Chang of single database private information retrieval, and present schemes with only logarithmic server Single database private information retrieval (1dPIR) is a cryptographic protocol between a database
Query Specific Fusion for Image Retrieval Shaoting Zhang2
Chen, Kuang-Yu
Query Specific Fusion for Image Retrieval Shaoting Zhang2 , Ming Yang1 , Timothee Cour1 , Kai Yu1 indexed by compact hashing codes both demonstrate excellent scalability. However, their retrieval propose a graph-based query specific fusion approach where multiple retrieval sets are merged and reranked
EVALUATING CLOUD RETRIEVAL ALGORITHMS WITH THE ARM BBHRP FRAMEWORK
EVALUATING CLOUD RETRIEVAL ALGORITHMS WITH THE ARM BBHRP FRAMEWORK E. Mlawer, T. Shippert, K. L closure analyses has been the evaluation of cloud microphysical retrieval algorithms. This evaluation for modeling studies. This poster details the continued effort to evaluate cloud property retrieval algorithms
Final report for the cryogenic retrieval demonstration
Valentich, D.J.; Yokuda, E.L.
1992-09-01T23:59:59.000Z
This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft{sup 3} of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a ``cold test pit`` that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 {times} 9 {times} 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub`s proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.
Final report for the cryogenic retrieval demonstration
Valentich, D.J.; Yokuda, E.L.
1992-09-01T23:59:59.000Z
This report documents a demonstration of a proposed buried transuranic waste retrieval concept that uses cryogenic ground freezing and remote excavation. At the Idaho National Engineering Laboratory (INEL), there are over 8 million ft[sup 3] of intermingled soil and transuranic (TRU) wastes in shallow land burial, and retrieval of the material is one of the options being considered by the Buried Waste Integrated Demonstration for the Environmental Restoration program. Cryogenically freezing contaminated soil and buried waste has been proposed as a way to greatly reduce or eliminate the climate the threat of contamination spread during retrieval activities. In support of this idea, a demonstration of an innovative ground freezing and retrieval technology was performed at the INEL. This initial demonstration was held near the Radioactive Waste Management Complex at a cold test pit'' that was built in 1988 as a test bed for the demonstration of retrieval contamination control technologies. This pit is not contaminated with any radioactive or hazardous wastes. Barrels and boxes filled with metals, plastics, tools, paper, cloth, etc. configured in the same manner as expected in contaminated pits and trenches are buried at the cold test pit. After design, fabrication, and shop testing, Sonsub mobilized to the field in early July 1992 to perform the field demonstration. It was planned to freeze and extract four pits, each 9 [times] 9 [times] 10 ft. Each pit represented a different configuration of buried waste (stacked boxes, stacked barrels, random dumped barrels and boxes, and random dumped barrels). Sonsub's proposed technology consisted of driving a series of freeze pipes into the soil and waste, using liquid nitrogen to freeze the mass, and extracting the soil and debris using a series of remote operated, bridge crane mounted tools. In conjunction with the freezing and removal activities, temperature and moisture measurements, and air monitoring were performed.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Lepri, Stefano, E-mail: stefano.lepri@isc.cnr.it [Consiglio Nazionale delle Ricerche, Istituto dei Sistemi Complessi, via Madonna del Piano 10, I-50019 Sesto Fiorentino (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, via G. Sansone 1, I-50019 Sesto Fiorentino (Italy); Pikovsky, Arkady [Department of Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str 24/25, Potsdam (Germany); Department of Control Theory, Nizhni Novgorod State University, Gagarin Av. 23, 606950, Nizhni Novgorod (Russian Federation)
2014-12-01T23:59:59.000Z
We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: The same wave is transmitted differently in two directions. Periodic regimes of scattering are analyzed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a “chaotic diode,” where transmission is periodic in one direction and chaotic in the opposite one, is reported.
Nonreciprocal wave scattering on nonlinear string-coupled oscillators
Stefano Lepri; Arkady Pikovsky
2014-10-29T23:59:59.000Z
We study scattering of a periodic wave in a string on two lumped oscillators attached to it. The equations can be represented as a driven (by the incident wave) dissipative (due to radiation losses) system of delay differential equations of neutral type. Nonlinearity of oscillators makes the scattering non-reciprocal: the same wave is transmitted differently in two directions. Periodic regimes of scattering are analysed approximately, using amplitude equation approach. We show that this setup can act as a nonreciprocal modulator via Hopf bifurcations of the steady solutions. Numerical simulations of the full system reveal nontrivial regimes of quasiperiodic and chaotic scattering. Moreover, a regime of a "chaotic diode", where transmission is periodic in one direction and chaotic in the opposite one, is reported.
Reheating-volume measure in the string theory landscape
Winitzki, Sergei [Department of Physics, Ludwig-Maximilians University, Munich (Germany)
2008-12-15T23:59:59.000Z
I recently proposed the ''reheating-volume'' (RV) prescription as a possible solution to the measure problem in ''multiverse'' cosmology. The goal of this work is to extend the RV measure to scenarios involving bubble nucleation, such as the string theory landscape. In the spirit of the RV prescription, I propose to calculate the distribution of observable quantities in a landscape that is conditioned in probability to nucleate a finite total number of bubbles to the future of an initial bubble. A general formula for the relative number of bubbles of different types can be derived. I show that the RV measure is well defined and independent of the choice of the initial bubble type, as long as that type supports further bubble nucleation. Applying the RV measure to a generic landscape, I find that the abundance of Boltzmann brains is always negligibly small compared with the abundance of ordinary observers in the bubbles of the same type. As an illustration, I present explicit results for a toy landscape containing four vacuum states, and for landscapes with a single high-energy vacuum and a large number of low-energy vacua.
Towards a Realistic Picture of CP Violation in Heterotic String Models
Oleg Lebedev; Stephen Morris
2002-03-26T23:59:59.000Z
We find that dilaton dominated supersymmetry breaking and spontaneous CP violation can be achieved in heterotic string models with superpotentials singular at the fixed points of the modular group. A semi--realistic picture of CP violation emerges in such models: the CKM phase appears due to a complex VEV of the T-modulus, while the soft supersymmetric CP phases are absent due to an axionic--type symmetry.
Towards a Realistic Picture of CP Violation in Heterotic String Models
Lebedev, O; Lebedev, Oleg; Morris, Stephen
2002-01-01T23:59:59.000Z
We find that dilaton dominated supersymmetry breaking and spontaneous CP violation can be achieved in heterotic string models with superpotentials singular at the fixed points of the modular group. A semi--realistic picture of CP violation emerges in such models: the CKM phase appears due to a complex VEV of the T-modulus, while the soft supersymmetric CP phases are absent due to an axionic--type symmetry.
Single-shell tank retrieval program mission analysis report
Stokes, W.J.
1998-08-11T23:59:59.000Z
This Mission Analysis Report was prepared to provide the foundation for the Single-Shell Tank (SST) Retrieval Program, a new program responsible for waste removal for the SSTS. The SST Retrieval Program is integrated with other Tank Waste Remediation System activities that provide the management, technical, and operations elements associated with planning and execution of SST and SST Farm retrieval and closure. This Mission Analysis Report provides the basis and strategy for developing a program plan for SST retrieval. This Mission Analysis Report responds to a US Department of Energy request for an alternative single-shell tank retrieval approach (Taylor 1997).
Aerosol Retrievals from ARM SGP MFRSR Data
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Alexandrov, Mikhail
The Multi-Filter Rotating Shadowband Radiometer (MFRSR) makes precise simultaneous measurements of the solar direct normal and diffuse horizontal irradiances at six wavelengths (nominally 415, 500, 615, 673, 870, and 940 nm) at short intervals (20 sec for ARM instruments) throughout the day. Time series of spectral optical depth are derived from these measurements. Besides water vapor at 940 nm, the other gaseous absorbers within the MFRSR channels are NO2 (at 415, 500, and 615 nm) and ozone (at 500, 615, and 670 nm). Aerosols and Rayleigh scattering contribute atmospheric extinction in all MFRSR channels. Our recently updated MFRSR data analysis algorithm allows us to partition the spectral aerosol optical depth into fine and coarse modes and to retrieve the fine mode effective radius. In this approach we rely on climatological amounts of NO2 from SCIAMACHY satellite retrievals and use daily ozone columns from TOMS.
Bin Set 1 Calcine Retrieval Feasibility Study
R. D. Adams; S. M. Berry; K. J. Galloway; T. A. Langenwalter; D. A. Lopez; C. M. Noakes; H. K. Peterson; M. I. Pope; R. J. Turk
1999-10-01T23:59:59.000Z
At the Department of Energy's Idaho Nuclear Technology and Engineering Center, as an interim waste management measure, both mixed high-level liquid waste and sodium bearing waste have been solidified by a calculation process and are stored in the Calcine Solids Storage Facilities. This calcined product will eventually be treated to allow final disposal in a national geologic repository. The Calcine Solids Storage Facilities comprise seven ''bit sets.'' Bin Set 1, the first to be constructed, was completed in 1959, and has been in service since 1963. It is the only bin set that does not meet current safe-shutdown earthquake seismic criteria. In addition, it is the only bin set that lacks built-in features to aid in calcine retrieval. One option to alleviate the seismic compliance issue is to transport the calcine from Bin Set 1 to another bin set which has the required capacity and which is seismically qualified. This report studies the feasibility of retrieving the calcine from Bi n Set 1 and transporting it into Bin Set 6 which is located approximately 650 feet away. Because Bin Set 1 was not designed for calcine retrieval, and because of the high radiation levels and potential contamination spread from the calcined material, this is a challenging engineering task. This report presents preconceptual design studies for remotely-operated, low-density, pneumatic vacuum retrieval and transport systems and equipment that are based on past work performed by the Raytheon Engineers and Constructors architectural engineering firm. The designs presented are considered feasible; however, future development work will be needed in several areas during the subsequent conceptual design phase.
Open string amplitudes of closed topological vertex
Takasaki, Kanehisa
2015-01-01T23:59:59.000Z
The closed topological vertex is the simplest "off-strip" case of non-compact toric Calabi-Yau threefolds with acyclic web diagrams. By the diagrammatic method of topological vertex, open string amplitudes of topological string theory therein can be obtained by gluing a single topological vertex to an "on-strip" subdiagram of the tree-like web diagram. If non-trivial partitions are assigned to just two parallel external lines of the web diagram, the amplitudes can be calculated with the aid of techniques borrowed from the melting crystal models. These amplitudes are thereby expressed as matrix elements, modified by simple prefactors, of an operator product on the Fock space of 2D charged free fermions. This fermionic expression can be used to derive $q$-difference equations for generating functions of special subsets of the amplitudes. These $q$-difference equations may be interpreted as the defining equation of a quantum mirror curve.
Signal connection for a downhole tool string
Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Bradford, Kline; Fox, Joe; Briscoe, Michael
2006-08-29T23:59:59.000Z
A signal transmission connection for a tool string used in exploration and production of natural resources, namely: oil, gas, and geothermal energy resources. The connection comprises first and second annular elements deployed in cooperative association with each other. The respective elements comprise inductive transducers that are capable of two-way signal transmission between each other, with downhole components of the tool string, and with ground-level equipment. The respective inductive transducers comprise one or more conductive loops housed within ferrite troughs, or within ferrite trough segments. When energized, the conductive loops produce a magnetic field suitable for transmitting the signal. The second element may be rotational in drilling applications. The respective elements may be fitted with electronic equipment to aid and manipulate the transmission of the signal. The first element may also be in communication with the World Wide Web.
Vacuum selection on the string landscape
Tetteh-Lartey, Edward [Department of Physics, Texas A and M University, College Station, Texas 77845 (United States)
2007-05-15T23:59:59.000Z
I examine some nonanthropic approaches to the string landscape. These approaches are based on finding the initial conditions of the universe using the wave function of the multiverse to select the most probable vacuum out of this landscape. All approaches tackled so far seem to have their own problems and there is no clear-cut alternative to anthropic reasoning. I suggest that finding the initial conditions may be irrelevant since all possible vacua on the landscape are possible initial state conditions and eternal inflation could generate all the other vacua. We are now left to reason out why we are observing the small value of the cosmological constant. I address this issue in the context of noncritical string theory in which all values of the cosmological constant on the landscape are departures from the critical equilibrium state.
Strings, vortex rings, and modes of instability
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gubser, Steven S.; Nayar, Revant; Parikh, Sarthak
2015-03-01T23:59:59.000Z
We treat string propagation and interaction in the presence of a background Neveu–Schwarz three-form field strength, suitable for describing vortex rings in a superfluid or low-viscosity normal fluid. A circular vortex ring exhibits instabilities which have been recognized for many years, but whose precise boundaries we determine for the first time analytically in the small core limit. Two circular vortices colliding head-on exhibit stronger instabilities which cause splitting into many small vortices at late times. We provide an approximate analytic treatment of these instabilities and show that the most unstable wavelength is parametrically larger than a dynamically generated length scalemore »which in many hydrodynamic systems is close to the cutoff. We also summarize how the string construction we discuss can be derived from the Gross–Pitaevskii Lagrangian, and also how it compares to the action for giant gravitons.« less
Open string amplitudes of closed topological vertex
Kanehisa Takasaki; Toshio Nakatsu
2015-07-25T23:59:59.000Z
The closed topological vertex is the simplest "off-strip" case of non-compact toric Calabi-Yau threefolds with acyclic web diagrams. By the diagrammatic method of topological vertex, open string amplitudes of topological string theory therein can be obtained by gluing a single topological vertex to an "on-strip" subdiagram of the tree-like web diagram. If non-trivial partitions are assigned to just two parallel external lines of the web diagram, the amplitudes can be calculated with the aid of techniques borrowed from the melting crystal models. These amplitudes are thereby expressed as matrix elements, modified by simple prefactors, of an operator product on the Fock space of 2D charged free fermions. This fermionic expression can be used to derive $q$-difference equations for generating functions of special subsets of the amplitudes. These $q$-difference equations may be interpreted as the defining equation of a quantum mirror curve.
Jet fragmentation and gauge/string duality
Yoshitaka Hatta; Toshihiro Matsuo
2008-05-27T23:59:59.000Z
We consider an analog of e^+e^- annihilation in gauge theories which have a dual string description in asymptotically AdS_5 space and discuss the nature of jet fragmentation. We construct the timelike anomalous dimension which governs the scale dependence of the fragmentation function. In the limit of infinite 't Hooft coupling, the average multiplicity rises linearly with the energy and the inclusive spectrum is peaked at the kinematical boundary.
Traversable wormholes in a string cloud
Martin Richarte; Claudio Simeone
2007-11-14T23:59:59.000Z
We study spherically symmetric thin-shell wormholes in a string cloud background in (3+1)-dimensional spacetime. The amount of exotic matter required for the construction, the traversability and the stability under radial perturbations, are analyzed as functions of the parameters of the model. Besides, in the Appendices a non perturbative approach to the dynamics and a possible extension of the analysis to a related model are briefly discussed.
Two Dimensional QCD is a String Theory
David J. Gross; Washington Taylor
1993-01-18T23:59:59.000Z
The partition function of two dimensional QCD on a Riemann surface of area $A$ is expanded as a power series in $1/N$ and $A$. It is shown that the coefficients of this expansion are precisely determined by a sum over maps from a two dimensional surface onto the two dimensional target space. Thus two dimensional QCD has a simple interpretation as a closed string theory.
String melting in a photon bath
Karouby, Johanna, E-mail: karoubyj@mit.edu [Center for Theoretical Physics and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachussetts 02139 (United States)
2013-10-01T23:59:59.000Z
We compute the decay rate of a metastable cosmic string in contact with a thermal bath by finding the instanton solution. The new feature is that this decay rate is found in the context of non thermal scalar fields in contact with a thermal bath of photons. In general, to make topologically unstable strings stable, one can couple them to such a bath. The resulting plasma effect creates metastable configurations which can decay from the false vacuum to the true vacuum. In our specific set-up, the instanton computation is realized for the case of two out-of-equilibrium complex scalar fields: one is charged and coupled to the photon field, and the other is neutral. New effects coming from the thermal bath of photons make the radius of the nucleated bubble and most of the relevant physical quantities temperature-dependent. However, the temperature appears in a different way than in the purely thermal case, where all scalar fields are in thermal equilibrium. As a result of the tunneling, the core of the initial string melts while bubbles of true vacuum expand at the speed of light.
Cosmic strings in hidden sectors: 2. Cosmological and astrophysical signatures
Long, Andrew J.; Vachaspati, Tanmay, E-mail: andrewjlong@asu.edu, E-mail: tvachasp@asu.edu [Physics Department, Arizona State University, Tempe, Arizona 85287 (United States)
2014-12-01T23:59:59.000Z
Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the cosmological and astrophysical observables that could be associated with the presence of dark strings in our universe with an emphasis on low-scale models, perhaps TeV . Specifically, we consider constraints from nucleosynthesis and CMB spectral distortions, and we calculate the predicted fluxes of diffuse gamma ray cascade photons and cosmic rays. For strings as light as TeV, we find that the predicted level of these signatures is well below the sensitivity of the current experiments, and therefore low scale cosmic strings in hidden sectors remain unconstrained. Heavier strings with a mass scale in the range 10{sup 13} GeV to 10{sup 15} GeV are at tension with nucleosynthesis constraints.
Strings on AdS Wormholes and Nonsingular Black Holes
H. Lu; Justin F. Vazquez-Poritz; Zhibai Zhang
2014-10-22T23:59:59.000Z
Certain AdS black holes in the STU model can be conformally scaled to wormhole and black hole solutions of an f(R) type theory which have two asymptotically AdS regions and are completely free of curvature singularities. While there is a delta-function source for the dilaton, classical string probes are not sensitive to this singularity. If the AdS/CFT correspondence can be applied in this context, then the wormhole background describes a phase in which two copies of a conformal field theory interact with each other, whereas the nonsingular black hole describes entangled states. By studying the behavior of open strings on these backgrounds, we extract a number of features of the quarks and anti-quarks that live in the field theories. In the interacting phase, we find that there is a maximum speed with which the quarks can move without losing energy, beyond which energy is transferred from a quark in one field theory to a quark in the other. We also compute the rate at which moving quarks within entangled states lose energy to the two surrounding plasmas. While a quark-antiquark pair within a single field theory exhibits Coulomb interaction for small separation, a quark in one field theory exhibits spring-like confinement with an anti-quark in the other field theory. For the entangled states, we study how the quark-antiquark screening length depends on temperature and chemical potential. In the interacting phase of the two field theories, a quadruplet made up of one quark-antiquark pair in each field theory can undergo transitions involving how the quarks and antiquarks are paired in terms of the screening.
A casing string model for the personal computer
Zuniga-Pflucker, Manuel Pablo
1988-01-01T23:59:59.000Z
is often inaccurate - too conservative for shallow strings, too liberal for deep strings. Most wells, probably 90 percent of them, are designed . using uniaxial and biaxial techniques that rely heavily on safety factors to ensure adequate designs. While... uniaxial or biaxial conditions rather than triaxial and the uncertainty of the assumed worst conditions, conventional casing design relies heavily on safety factors to ensure an adequate design. When designing or analyzing a casing string...
Open String Theory in 1+1 Dimensions
M. Bershadsky; D. Kutasov
1991-10-14T23:59:59.000Z
We show that tree level open two dimensional string theory is exactly solvable; the solution exhibits some unusual features, and is qualitatively different from the closed case. The open string ``tachyon'' S -- matrix describes free fermions, which can be interpreted as the quarks at the ends of the string. These ``quarks'' live naturally on a lattice in space-time. We also find an exact vacuum solution of the theory, corresponding to a charged black hole.
A Query-by-Example Content-Based Image Retrieval System of Non-Melanoma Skin Lesions
Fisher, Bob
A Query-by-Example Content-Based Image Retrieval System of Non-Melanoma Skin Lesions Lucia classes, including two non-melanoma cancer types are used. Colour and texture features are extracted from for images acquired by epiluminescence microscopy (ELM or dermoscopy) and they focus on melanoma, which
N. Seiberg; L. Susskind; N. Toumbas
2000-05-04T23:59:59.000Z
Searching for space/time noncommutativity we reconsider open strings in a constant background electric field. The main difference between this situation and its magnetic counterpart is that here there is a critical electric field beyond which the theory does not make sense. We show that this critical field prevents us from finding a limit in which the theory becomes a field theory on a noncommutative spacetime. However, an appropriate limit toward the critical field leads to a novel noncritical string theory on a noncommutative spacetime.
The Hubble Web: The Dark Matter Problem and Cosmic Strings
Stephon Alexander
2007-02-27T23:59:59.000Z
I propose a reinterpretation of cosmic dark matter in which a rigid network of cosmic strings formed at the end of inflation. The cosmic strings fulfill three functions: At recombination they provide an accretion mechanism for virializing baryonic and warm dark matter into disks. These cosmic strings survive as configurations which thread spiral and elliptical galaxies leading to the observed flatness of rotation curves and the Tully-Fisher relation. We find a relationship between the rotational velocity of the galaxy and the string tension and discuss the testability of this model.
String Loop Corrections to Stable Non-BPS Branes
N. D. Lambert; I. Sachs
2000-10-31T23:59:59.000Z
We calculate the string loop corrections to the tachyon potential for stable non-BPS Dp-branes on the orbifold T^4/Z_2. We find a non-trivial phase structure and we show that, after tachyon condensation, the non-BPS Dp-branes are attracted to each other for p=0,1,2. We then identify the corresponding closed string boundary states together with the massless long range fields they excite. For p=3,4 the string loop correction diverge. We identify the massless closed string fields responsible for these divergencies and regularise the partition function using a Fischler-Susskind mechanism.
Efficient solutions for the Far From Most String Problem
Daniele Ferone,,,
niques for string selection and comparison problems in genomics. IEEE. Engineering in Medicine and Biology Magazine, 24(3):81–87, 2005. [29] C.A.S. Oliveira ...
Non-linear sigma-models and string theories
Sen, A.
1986-10-01T23:59:59.000Z
The connection between sigma-models and string theories is discussed, as well as how the sigma-models can be used as tools to prove various results in string theories. Closed bosonic string theory in the light cone gauge is very briefly introduced. Then, closed bosonic string theory in the presence of massless background fields is discussed. The light cone gauge is used, and it is shown that in order to obtain a Lorentz invariant theory, the string theory in the presence of background fields must be described by a two-dimensional conformally invariant theory. The resulting constraints on the background fields are found to be the equations of motion of the string theory. The analysis is extended to the case of the heterotic string theory and the superstring theory in the presence of the massless background fields. It is then shown how to use these results to obtain nontrivial solutions to the string field equations. Another application of these results is shown, namely to prove that the effective cosmological constant after compactification vanishes as a consequence of the classical equations of motion of the string theory. 34 refs. (LEW)
CMB ISW-lensing bispectrum from cosmic strings
Daisuke Yamauchi; Yuuiti Sendouda; Keitaro Takahashi
2014-10-21T23:59:59.000Z
We study the effect of weak lensing by cosmic (super-)strings on the higher-order statistics of the cosmic microwave background (CMB). A cosmic string segment is expected to cause weak lensing as well as an integrated Sachs-Wolfe (ISW) effect, the so-called Gott-Kaiser-Stebbins (GKS) effect, to the CMB temperature fluctuation, which are thus naturally cross-correlated. We point out that, in the presence of such a correlation, yet another kind of the post-recombination CMB temperature bispectra, the ISW-lensing bispectra, will arise in the form of products of the auto- and cross-power spectra. We first present an analytic method to calculate the autocorrelation of the temperature fluctuations induced by the strings, and the cross-correlation between the temperature fluctuation and the lensing potential both due to the string network. In our formulation, the evolution of the string network is assumed to be characterized by the simple analytic model, the velocity-dependent one scale model, and the intercommutation probability is properly incorporated in orderto characterize the possible superstringy nature. Furthermore, the obtained power spectra are dominated by the Poisson-distributed string segments, whose correlations are assumed to satisfy the simple relations. We then estimate the signal-to-noise ratios of the string-induced ISW-lensing bispectra and discuss the detectability of such CMB signals from the cosmic string network. It is found that in the case of the smaller string tension, $G\\mu\\ll 10^{-7}$\\,, the ISW-lensing bispectrum induced by a cosmic string network can constrain the string-model parameters even more tightly than the purely GKS-induced bispectrum in the ongoing and future CMB observations on small scales.
Light Syntactically-Based Index Pruning for Information Retrieval
Lioma, C.
Lioma,C. Ounis,I. Proceedings of the 29th European Conference on Information Retrieval (ECIR), Rome, Italy, 2007. LNCS, Springer
The viscosity bound in string theory
Aninda Sinha; Robert C. Myers
2009-09-11T23:59:59.000Z
The ratio of shear viscosity to entropy density $\\eta/s$ of any material in nature has been conjectured to have a lower bound of $1/4\\pi$, the famous KSS bound. We examine string theory models for evidence in favour of and against this conjecture. We show that in a broad class of models quantum corrections yield values of $\\eta/s$ just above the KSS bound. However, incorporating matter fields in the fundamental representation typically leads to violations of this bound. We also outline a program to extend AdS/CFT methods to RHIC phenomenology.
Lattice String Breaking and Heavy Meson Decays
I T Drummond; R R Horgan
1998-11-11T23:59:59.000Z
We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from the decay rate for $\\Upsilon(4S)\\to B{\\bar B}$. We extend the calculation to achieve rough estimates for the contributions of channels involving $B, B^*, B_s and B_s^*$ mesons to the width of the $\\Upsilon(5S)$.
Higher-Spin Geometry and String Theory
D. Francia; A. Sagnotti
2006-02-14T23:59:59.000Z
The theory of freely-propagating massless higher spins is usually formulated via gauge fields and parameters subject to trace constraints. We summarize a proposal allowing to forego them by introducing only a pair of additional fields in the Lagrangians. In this setting, external currents satisfy usual Noether-like conservation laws, the field equations can be nicely related to those emerging from Open String Field Theory in the low-tension limit, and if the additional fields are eliminated without reintroducing the constraints a geometric, non-local description of the theory manifests itself.
Quantum string cosmology in the phase space
Ruben Cordero; Erik Diaz; Hugo Garcia-Compean; Francisco J. Turrubiates
2011-09-22T23:59:59.000Z
Deformation quantization is applied to quantize gravitational systems coupled with matter. This quantization procedure is performed explicitly for quantum cosmology of these systems in a flat minisuper(phase)space. The procedure is employed in a quantum string minisuperspace corresponding to an axion-dilaton system in an isotropic FRW Universe. The Wheeler-DeWitt-Moyal equation is obtained and its corresponding Wigner function is given analytically in terms of Meijer's functions. Finally, this Wigner functions is used to extract physical information of the system.
Dynamics of a self-gravitating thin cosmic string
B. Boisseau; C. Charmousis; B. Linet
1997-02-06T23:59:59.000Z
We assume that a self-gravitating thin string can be locally described by what we shall call a smoothed cone. If we impose a specific constraint on the model of the string, then its central line obeys the Nambu-Goto equations. If no constraint is added, then the worldsheet of the central line is a totally geodesic surface.
RENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT
Janson, Svante
RENEWAL THEORY IN ANALYSIS OF TRIES AND STRINGS: EXTENDED ABSTRACT SVANTE JANSON Abstract. We give a survey of a number of simple applications of renewal theory to problems on random strings, in particular to tries and Khodak and Tunstall codes. 1. Introduction Although it long has been realized that renewal
Gravitational Radiation from Travelling Waves on D-Strings
Julie D. Blum
2003-08-21T23:59:59.000Z
Boundary states that preserve supersymmetry are constructed for fractional D-strings with travelling waves on a ${\\bf C}^3/ {{\\bf Z}_2\\times {\\bf Z}_2}$ orbifold. The gravitational radiation emitted between two D-strings with antiparallel travelling waves is calculated.
The M Theory Five-Brane and the Heterotic String
John H. Schwarz
1997-05-13T23:59:59.000Z
Brane actions with chiral bosons present special challenges. Recent progress in the description of the two main examples -- the M theory five-brane and the heterotic string -- is described. Also, double dimensional reduction of the M theory five-brane on K3 is shown to give the heterotic string.
Character String Predicate Based Automatic Software Test Data Generation
Lyu, Michael R.
Character String Predicate Based Automatic Software Test Data Generation Ruilian Zhao Computer is an important element in programming. A problem that needs further research is how to automatically generate generation of program paths including character string predicates, and the effectiveness of this approach
SCHWARTZ TENNIS CENTER DAMPENERS, GRIPS, STRING, TENNIS BALLS
Pittendrigh, Barry
SCHWARTZ TENNIS CENTER DAMPENERS, GRIPS, STRING, TENNIS BALLS STRINGING:(We attempt to have all, Durability $34.00 Luxilon Big Banger Rough, Spin, Control, Durability $34.00 Prince Lightning, 16 g: $5.00 Wilson Pro Feel Plus Dampener: $4.00 TENNIS BALLS: Wilson US Open Tennis Balls: $3.25 SPECIAL
Resonant acoustic transducer system for a well drilling string
Kent, William H. (Westford, MA); Mitchell, Peter G. (Concord, MA)
1981-01-01T23:59:59.000Z
For use in transmitting acoustic waves propagated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting resonant operation in the desired low frequency range.
Resonant acoustic transducer system for a well drilling string
Nardi, Anthony P. (Burlington, MA)
1981-01-01T23:59:59.000Z
For use in transmitting acoustic waves propated along a well drilling string, a piezoelectric transducer is provided operating in the relatively low loss acoustic propagation range of the well drilling string. The efficiently coupled transmitting transducer incorporates a mass-spring-piezoelectric transmitter combination permitting a resonant operation in the desired low frequency range.
Quantum Fusion of Strings (Flux Tubes) and Domain Walls
S. Bolognesi; M. Shifman; M. B. Voloshin
2009-05-20T23:59:59.000Z
We consider formation of composite strings and domain walls as a result of fusion of two elementary objects (elementary strings in the first case and elementary walls in the second) located at a distance from each other. The tension of the composite object T_2 is assumed to be less than twice the tension of the elementary object T_1, so that bound states are possible. If in the initial state the distance d between the fusing strings or walls is much larger than their thickness and satisfies the conditions T_1 d^2 >> 1 (in the string case) and T_1 d^3 >> 1 (in the wall case), the problem can be fully solved quasiclassically. The fusion probability is determined by the first, "under the barrier" stage of the process. We find the bounce configuration and its extremal action S_B. In the wall problem e^{-S_B} gives the fusion probability per unit time per unit area. In the string case, due to a logarithmic infrared divergence, the problem is well formulated only for finite-length strings. The fusion probability per unit time can be found in the limit in which the string length is much larger than the distance between two merging strings.
Comment about UV regularization of basic commutators in string theories
A. Yu. Kamenshchik; I. M. Khalatnikov; M. Martellini
1998-06-24T23:59:59.000Z
Recently proposed by Hwang, Marnelius and Saltsidis zeta regularization of basic commutators in string theories is generalized to the string models with non-trivial vacuums. It is shown that implementation of this regularization implies the cancellation of dangerous terms in the commutators between Virasoro generators, which break Jacobi identity.
Tachyon condensation in boundary string field theory at one loop
K. Bardakci; A. Konechny
2001-08-21T23:59:59.000Z
We compute the one-loop partition function for quadratic tachyon background in open string theory. Both closed and open string representations are developed. Using these representations we study the one-loop divergences in the partition function in the presence of the tachyon background. The divergences due to the open and closed string tachyons are treated by analytic continuation in the tachyon mass squared. We pay particular attention to the imaginary part of the analytically continued expressions. The last one gives the decay rate of the unstable vacuum. The dilaton tadpole is also given some partial consideration. The partition function is further used to study corrections to tachyon condensation processes describing brane descent relations. Assuming the boundary string field theory prescription for construction of the string field action via partition function holds at one loop level we study the one-loop corrections to the tachyon potential and to the tensions of lower-dimensional branes.
String stabilized ribbon growth a method for seeding same
Sachs, Emanuel M. (39 Harding Ave., Belmont, MA 02178)
1987-08-25T23:59:59.000Z
This invention is a method of initiating or seeding the growth of a crystalline or polycrystalline ribbon by the String Stabilized Ribbon Growth Method. The method for seeding the crystal growth comprises contacting a melt surface with a seed and two strings used in edge stabilization. The wetted strings attach to the wetted seed as a result of the freezing of the liquid melt. Upon drawing the seed, which is attached to the strings, away from the melt surface a melt liquid meniscus, a seed junction, and a growth interface forms. Further pulling of the attached seed causes a crystal ribbon to grow at the growth interface. The boundaries of the growing ribbon are: at the top the seed junction, at the bottom the freezing boundary of the melt liquid meniscus, and at the edges frozen-in strings.
Strings, black holes, and quantum information
Kallosh, Renata; Linde, Andrei [Department of Physics, Stanford University, Stanford, California 94305 (United States)
2006-05-15T23:59:59.000Z
We find multiple relations between extremal black holes in string theory and 2- and 3-qubit systems in quantum information theory. We show that the entropy of the axion-dilaton extremal black hole is related to the concurrence of a 2-qubit state, whereas the entropy of the STU black holes, Bogomol'nyi-Prasad-Sommerfield (BPS) as well as non-BPS, is related to the 3-tangle of a 3-qubit state. We relate the 3-qubit states with the string theory states with some number of D-branes. We identify a set of large black holes with the maximally entangled Greenberger, Horne, Zeilinger (GHZ) class of states and small black holes with separable, bipartite, and W states. We sort out the relation between 3-qubit states, twistors, octonions, and black holes. We give a simple expression for the entropy and the area of stretched horizon of small black holes in terms of a norm and 2-tangles of a 3-qubit system. Finally, we show that the most general expression for the black hole and black ring entropy in N=8 supergravity/M theory, which is given by the famous quartic Cartan E{sub 7(7)} invariant, can be reduced to Cayley's hyperdeterminant describing the 3-tangle of a 3-qubit state.
Open strings in the plane wave background I: Quantization and symmetries
Kostas Skenderis; Marika Taylor
2003-06-15T23:59:59.000Z
We systematically investigate open strings in the plane wave background of type IIB string theory. We carefully analyze possible boundary conditions for open strings and find static as well as time-dependent branes. The branes fall into equivalence classes depending on whether they are related by the action of target space isometries. In particular static branes localized at the origin of transverse space and certain time-dependent branes fall into the same equivalence class. We analyze thoroughly the symmetries of all branes we discuss. Apart from symmetries descending from target space isometries, the worldsheet action being free admits a countably infinite number of other global worldsheet symmetries. We find that one can use such worldsheet symmetries to restore seemingly broken target space symmetries. In particular, we show that D-branes localized at arbitrary constant positions which were thought to be 1/4 supersymmetric in fact have sixteen supercharges whilst D-branes which were thought to be non-supersymmetric have eight supercharges. We discuss in detail the quantization in all cases.
Aho-Corasick String Matching on Shared and Distributed Memory Parallel Architectures
Tumeo, Antonino; Villa, Oreste; Chavarría-Miranda, Daniel
2012-03-01T23:59:59.000Z
String matching is at the core of many critical applications, including network intrusion detection systems, search engines, virus scanners, spam filters, DNA and protein sequencing, and data mining. For all of these applications string matching requires a combination of (sometimes all) the following characteristics: high and/or predictable performance, support for large data sets and flexibility of integration and customization. Many software based implementations targeting conventional cache-based microprocessors fail to achieve high and predictable performance requirements, while Field-Programmable Gate Array (FPGA) implementations and dedicated hardware solutions fail to support large data sets (dictionary sizes) and are difficult to integrate and customize. The advent of multicore, multithreaded, and GPU-based systems is opening the possibility for software based solutions to reach very high performance at a sustained rate. This paper compares several software-based implementations of the Aho-Corasick string searching algorithm for high performance systems. We discuss the implementation of the algorithm on several types of shared-memory high-performance architectures (Niagara 2, large x86 SMPs and Cray XMT), distributed memory with homogeneous processing elements (InfiniBand cluster of x86 multicores) and heterogeneous processing elements (InfiniBand cluster of x86 multicores with NVIDIA Tesla C10 GPUs). We describe in detail how each solution achieves the objectives of supporting large dictionaries, sustaining high performance, and enabling customization and flexibility using various data sets.
Phase Retrieval for Fresnel Measurements Using a Shearlet Sparsity Constraint
Plonka, Gerlind
Phase Retrieval for Fresnel Measurements Using a Shearlet Sparsity Constraint Stefan Loock Gerlind Plonka March 25, 2014 Abstract We consider the problem of phase retrieval in the Fresnel regime be used for phase reconstruction with Fresnel data. As it turns out, the shearlet sparsity constraint
Tropospheric Ozone Satellite Retrievals in the Pacific Northwest
Collins, Gary S.
Tropospheric Ozone Satellite Retrievals in the Pacific Northwest Jacqueline Costello1, Farren: Tropospheric ozone is difficult to retrieve from satellites because of the abundance of ozone in the stratosphere. Tropospheric ozone has become a significant environmental issue and can be exacerbated by UT
8, 42674308, 2008 3-D retrieval of cloud
Paris-Sud XI, Université de
ACPD 8, 42674308, 2008 3-D retrieval of cloud particle profiles T. Zinner et al. Title Page.0 License. Atmospheric Chemistry and Physics Discussions Remote sensing of cloud sides of deep convection: towards a three-dimensional retrieval of cloud particle size profiles T. Zinner 1,2 , A. Marshak 1 , S
Audio-Visual Multimedia Retrieval on Mobile Iftikhar Ahmad1
Gabbouj, Moncef
8 Audio-Visual Multimedia Retrieval on Mobile Devices Iftikhar Ahmad1 and Moncef Gabbouj2 1 Nokia's multimedia mobile devices and the Internet have led to the widespread exchange of multimedia contents. This and proprietary application programming interfaces. Therefore content-based multimedia retrieval from mobile
A NOVEL MULTIMEDIA RETRIEVAL TECHNIQUE: PROGRESSIVE QUERY (WHY WAIT?)
Gabbouj, Moncef
A NOVEL MULTIMEDIA RETRIEVAL TECHNIQUE: PROGRESSIVE QUERY (WHY WAIT?) Serkan Kiranyaz and Moncef@cs.tut.fi, moncef.gabbouj@tut.fi ABSTRACT One of the challenges in the development of content-based multimedia who are accustomed to making queries and thus retrieving any multimedia item from a large scale
Simultaneous Wind and Rain Retrieval for ERS Scatterometer Measurements
Long, David G.
Simultaneous Wind and Rain Retrieval for ERS Scatterometer Measurements Congling Nie and David G on the ESCAT wind-only retrieval has been evaluated. For high incidence angle measurements, the additional scattering of rain causes estimated wind speeds to appear higher than expected. It is also noted
Towards a Logical Reconstruction of Information Retrieval Theory
Sebastiani, Fabrizio
Towards a Logical Reconstruction of Information Retrieval Theory Fabrizio Sebastiani Istituto di theory". We show that precisely the same distinction can be applied to logical models of IR developed so in the history of information retrieval, sharply summarised the status of IR theory by saying that "(. . . ) deep
Instruction Guide Saving and Retrieving Items from My Favorites
Sin, Peter
Instruction Guide Saving and Retrieving Items from My Favorites Updated April 2015 © Office this instruction guide to learn how to save items in My Favorites in myUF Market for re-use on a regular basis. My to place an order. The price will be automatically updated upon retrieval for items saved from using
Information Retrieval and DempsterShafer's Theory of Evidence
Lalmas, Mounia
Information Retrieval and DempsterShafer's Theory of Evidence Mounia Lalmas Department describes the use of the DempsterShafer theory of evidence to construct an information retrieval model that aims to capture four essential features of information: structure, significance, uncertainty
Information interaction A Cognitive Analysis of Information Retrieval
Mizzaro, Stefano
Information interaction 233 A Cognitive Analysis of Information Retrieval Stefano Mizzaro The lackness of a formal account is probably one of the most evident of the shortcomings of information retrieval: concepts like information, information need, and relevance are neither well understood nor
INFERENCING IN INFORMATION RETRIEVAL Alexa T. McCray
INFERENCING IN INFORMATION RETRIEVAL Alexa T. McCray National Library of Medicine Bethesda that provides access to extensive biomedical knowledge sources, and a retrieval module that allows us to carry, or thesaurus, which is the primary access point to the material at search time. For example, the National
Storage and retrieval of large digital images
Bradley, J.N.
1998-01-20T23:59:59.000Z
Image compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets T{sub ij}(x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles T{sub ij}(x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles T{sub ij}(x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval. 6 figs.
Storage and retrieval of large digital images
Bradley, Jonathan N. (Los Alamos, NM)
1998-01-01T23:59:59.000Z
Image compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets T.sub.ij (x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles T.sub.ij (x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles T.sub.ij (x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval.
Pan, Laura
Ozone Profile Retrieval from an Advanced Infrared Sounder: Experiments with Tropopause for retrieving atmospheric ozone profile information from advanced satellite infrared sounders, this study investigates various methods to optimize ozone retrievals. A set of retrieval experiments has been performed
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP
Dehene, Frank
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP C. E. R. Alves present a coarse-grained parallel algorithm for solving the string edit distance problem for a string A and all substrings of a string C. Our method is based on a novel CGM/BSP parallel dynamic programming
Euclidean spinor Green's functions in the spacetime of a straight cosmic string
B. Linet
1994-12-19T23:59:59.000Z
We determine generally the spinor Green's function and the twisted spinor Green's function in an Euclidean space with a conical-type line singularity. In particular, in the neighbourhood of the point source, we expree them as a sum of the usual Euclidean spinor Green's functin and a regular term. In four dimensions, we use these determinations to calculate the vacuum energy density and the twisted one for a massless spinor field in the spacetime of a straight cosmic string. In the Minkowski spacetime, we determine explicitly the vacuum energy density for a massive twisted spinor field.
Dynamics of a global string with large Higgs boson mass
C. Charmousis; B. Boisseau; B. Linet
1998-01-12T23:59:59.000Z
We consider a self-gravitating string generated by a global vortex solution in general relativity. We investigate the Einstein and field equations of a global vortex in the region of its central line and at a distance from the centre of the order of the inverse of its Higgs boson mass. By combining the two we establish by a limiting process of large Higgs mass the dynamics of a self-gravitating global string. Under our assumptions the presence of gravitation restricts the world sheet of the global string to be totally geodesic.
First Structure Formation: II. Cosmic String + Hot Dark Matter Models
Tom Abel; Albert Stebbins; Peter Anninos; Michael L. Norman
1997-06-26T23:59:59.000Z
We examine the structure of baryonic wakes in the cosmological fluid which would form behind GUT-scale cosmic strings at early times (redshifts z > 100) in a neutrino-dominated universe. We show, using simple analytical arguments as well as 1- and 2-dimensional hydrodynamical simulations, that these wakes will NOT be able to form interesting cosmological objects before the neutrino component collapses. The width of the baryonic wakes (< 10 kpc comoving) is smaller than the scale of wiggles on the strings and are probably not enhanced by the wiggliness of the string network.
Accretion onto a black hole in a string cloud background
Apratim Ganguly; Sushant G. Ghosh; Sunil D. Maharaj
2014-09-28T23:59:59.000Z
We examine the accretion process onto the black hole with a string cloud background, where the horizon of the black hole has an enlarged radius $r_H=2 M/(1-\\alpha)$, due to the string cloud parameter $\\alpha\\; (0 \\leq \\alpha cloud parameter $\\alpha$. We also find the gas compression ratios and temperature profiles below the accretion radius and at the event horizon. It is shown that the mass accretion rate, for both the relativistic and the non-relativistic fluid by a black hole in the string cloud model, increases with increase in $\\alpha$.
Modified Dispersion Relations from Closed Strings in Toroidal Cosmology
Mar Bastero-Gil; Paul H. Frampton; Laura Mersini
2002-02-13T23:59:59.000Z
A long-standing problem of theoretical physics is the exceptionally small value of the cosmological constant $\\Lambda \\sim 10^{-120}$ measured in natural Planckian units. Here we derive this tiny number from a toroidal string cosmology based on closed strings. In this picture the dark energy arises from the correlation between momentum and winding modes that for short distances has an exponential fall-off with increasing values of the momenta.The freeze-out by the expansion of the background universe for these transplanckian modes may be interpreted as a frozen condensate of the closed-string modes in the three non-compactified spatial dimensions.
Fitting the Galaxy Rotation Curves: Strings versus NFW profile
Yeuk-Kwan E. Cheung; Feng Xu
2008-10-14T23:59:59.000Z
Remarkable fit of galaxy rotation curves is achieved using a simple model from string theory. The rotation curves of the same group of galaxies are also fit using dark matter model with the generalized Navarro-Frenk-White profile for comparison. String model utilizes three free parameters vs five in the dark matter model. The average chi-squared of the string model fit is 1.649 while that of the dark matter model is 1.513. The generalized NFW profile fits marginally better at a price of two more free parameters.
A note on string size evolution in phantom cosmology
Soon-Tae Hong
2015-04-05T23:59:59.000Z
We analyze evolution of string size in higher-dimensional cosmology with phantom field. Assuming that the Universe possesses the phantom field defined in a ten-dimensional spacetime, we predict string size which is claimed to be that of photon in nature at present. The Universe size increases as in the standard inflationary Universe model while the photon size decreases drastically at the early stage of the string evolution after the Big Bang. Moreover, the photon spin in the phantom Universe is analyzed in the framework of the stringy cosmology.
Light superconducting strings in the Galaxy
Francesc Ferrer; Tanmay Vachaspati
2006-08-08T23:59:59.000Z
Observations of the Milky Way by the SPI/INTEGRAL satellite have confirmed the presence of a strong 511 KeV gamma-ray line emission from the bulge, which require an intense source of positrons in the galactic center. These observations are hard to account for by conventional astrophysical scenarios, whereas other proposals, such as light DM, face stringent constraints from the diffuse gamma-ray background. Here we suggest that light superconducting strings could be the source of the observed 511 KeV emission. The associated particle physics, at the ~ 1 TeV scale, is within reach of planned accelerator experiments, while the distinguishing spatial distribution, proportional to the galactic magnetic field, could be mapped by SPI or by future, more sensitive, satellite missions.
String Theory, Supersymmetry, Unification, and All That
John H. Schwarz; Nathan Seiberg
1998-04-22T23:59:59.000Z
String theory and supersymmetry are theoretical ideas that go beyond the standard model of particle physics and show promise for unifying all forces. After a brief introduction to supersymmetry, we discuss the prospects for its experimental discovery in the near future. We then show how the magic of supersymmetry allows us to solve certain quantum field theories exactly, thus leading to new insights about field theory dynamics related to electric-magnetic duality. The discussion of superstring theory starts with its perturbation expansion, which exhibits new features including ``stringy geometry.'' We then turn to more recent non-perturbative developments. Using new dualities, all known superstring theories are unified, and their strong coupling behavior is clarified. A central ingredient is the existence of extended objects called branes.
Dark Energy Generated by Warped Cosmic Strings
Reinoud Jan Slagter
2014-07-29T23:59:59.000Z
If we live on the weak brane in a warped 5D bulk spacetime, gravitational waves and brane fluctuations can be generated by a part of the 5D Weyl tensor and carries information of the gravitational field outside the brane. We consider the U(1) self-gravitating scalar-gauge field on the warped spacetime without bulk matter. It turns out that "branons" can be formed dynamically, due to the modified energy-momentum tensor components of the cosmic string. It turns out that the parameter $\\alpha$, i.e., the gauge-to-scalar mass, changes from a value $>1$ to a value $wave energy. It is the time-dependent part of the warp factor which triggers this extraordinary behavior.
Axions as quintessence in string theory
Panda, Sudhakar [Harish-Chandra Research Institute, Allahabad 211019 (India); Sumitomo, Yoske; Trivedi, Sandip P. [Tata Institute of Fundamental Research, Mumbai 400005 (India)
2011-04-15T23:59:59.000Z
We construct a model of quintessence in string theory based on the idea of axion monodromy as discussed by McAllister, Silverstein and Westphal [L. McAllister, E. Silverstein, and A. Westphal, Phys. Rev. D 82, 046003 (2010)]. In the model, the quintessence field is an axion whose shift symmetry is broken by the presence of 5-branes which are placed in highly warped throats. This gives rise to a potential for the axion field which is slowly varying, even after incorporating the effects of moduli stabilization and supersymmetry breaking. We find that the resulting time dependence in the equation of state of dark energy is potentially detectable, depending on the initial conditions. The model has many very light extra particles which live in the highly warped throats, but these are hard to detect. A signal in the rotation of the CMB polarization can also possibly arise.
Renewal Strings for Cleaning Astronomical Databases
Storkey, Amos J; Williams, Christopher K I; Mann, Robert G
2014-01-01T23:59:59.000Z
Large astronomical databases obtained from sky surveys such as the SuperCOSMOS Sky Surveys (SSS) invariably suffer from a small number of spurious records coming from artefactual effects of the telescope, satellites and junk objects in orbit around earth and physical defects on the photographic plate or CCD. Though relatively small in number these spurious records present a significant problem in many situations where they can become a large proportion of the records potentially of interest to a given astronomer. In this paper we focus on the four most common causes of unwanted records in the SSS: satellite or aeroplane tracks, scratches fibres and other linear phenomena introduced to the plate, circular halos around bright stars due to internal reflections within the telescope and diffraction spikes near to bright stars. Accurate and robust techniques are needed for locating and flagging such spurious objects. We have developed renewal strings, a probabilistic technique combining the Hough transform, renewal...
Conformable apparatus in a drill string
Hall, David R. (Provo, UT); Hall, Jr., H. Tracy (Provo, UT); Pixton, David S. (Lehi, UT); Fox, Joe (Spanish Fork, UT)
2007-08-28T23:59:59.000Z
An apparatus in a drill string comprises an internally upset drill pipe. The drill pipe comprises a first end, a second end, and an elongate tube intermediate the first and second ends. The elongate tube and the ends comprising a continuous an inside surface with a plurality of diameters. A conformable metal tube is disposed within the drill pipe intermediate the ends thereof and terminating adjacent to the ends of the drill pipe. The conformable metal tube substantially conforms to the continuous inside surface of the metal tube. The metal tube may comprise a non-uniform section which is expanded to conform to the inside surface of the drill pipe. The non-uniform section may comprise protrusions selected from the group consisting of convolutions, corrugations, flutes, and dimples. The non-uniform section extends generally longitudinally along the length of the tube. The metal tube may be adapted to stretch as the drill pipes stretch.
Duality Symmetric String and M-Theory
David S. Berman; Daniel C. Thompson
2014-12-09T23:59:59.000Z
We review recent developments in duality symmetric string theory. We begin with the world sheet doubled formalism which describes strings in an extended space time with extra coordinates conjugate to winding modes. This formalism is T-duality symmetric and can accommodate non-geometric T-fold backgrounds which are beyond the scope of Riemannian geometry. Vanishing of the conformal anomaly of this theory can be interpreted as a set of spacetime equations for the background fields. These equations follow from an action principle that has been dubbed Double Field Theory (DFT). We review the aspects of generalised geometry relevant for DFT. We outline recent extensions of DFT and explain how, by relaxing the so-called strong constraint with a Scherk Schwarz ansatz, one can obtain backgrounds that simultaneously depend on both the regular and T-dual coordinates. This provides a purely geometric higher dimensional origin to gauged supergravities that arise from non-geometric compactification. We then turn to M-theory and describe recent progress in formulating an E_{n(n)} U-duality covariant description of the dynamics. We describe how spacetime may be extended to accommodate coordinates conjugate to brane wrapping modes and the construction of generalised metrics in this extend space that unite the bosonic fields of supergravity into a single object. We review the action principles for these theories and their novel gauge symmetries. We also describe how a Scherk Schwarz reduction can be applied in the M-theory context and the resulting relationship to the embedding tensor formulation of maximal gauged supergravities.
Entanglement accumulation, retrieval, and concentration in cavity QED
Daniel Ballester
2009-06-02T23:59:59.000Z
The ability to accumulate and retrieve entanglement in the fields of two remote cavities with pairs of two-level atoms is discussed. It is shown that this transfer and retrieval can be indeed ideal with a resonant interaction. The case of initial non-maximally entangled atomic pairs is also considered. This leads to the possibility of concentrating entanglement into a single pair at the retrieval stage. A teleportation protocol based on the same setup is presented. This makes possible teleportation with built-in entanglement concentration.
Towards a metamaterial simulation of a spinning cosmic string
Tom G. Mackay; Akhlesh Lakhtakia
2009-11-21T23:59:59.000Z
Establishing the constitutive parameters of a nonhomogeneous bianisotropic medium that is equivalent to the spacetime metric of a spinning cosmic string, in a noncovariant formalism, we found a metamaterial route to investigate the existence of closed timelike curves.
The Fourier-Mukai Transform in String Theory
Bjorn Andreas
2005-05-30T23:59:59.000Z
The article surveys aspects of the Fourier-Mukai transform, its relative version and some of its applications in string theory. To appear in Encyclopedia of Mathematical Physics, published by Elsevier in early 2006. Comments/corrections welcome.
Efficient Solutions for the Far From Most String Problem
Paola Festa
2011-04-07T23:59:59.000Z
Apr 7, 2011 ... Efficient Solutions for the Far From Most String Problem. Paola Festa(paola.festa ***at*** unina.it) Panos M. Pardalos(pardalos ***at*** ufl.edu).
Lovelock black holes in a string cloud background
Tae-Hun Lee; Dharmanand Baboolal; Sushant G. Ghosh
2015-06-11T23:59:59.000Z
We present an exact static, spherically symmetric black hole solution to the third order Lovelock gravity with a string cloud background in seven dimensions for the special case when the second and third order Lovelock coefficients are related via $\\tilde{\\alpha}^2_2=3\\tilde{\\alpha}_3\\;(\\equiv\\alpha^2)$. Further, we examine thermodynamic properties of this black hole to obtain exact expressions for mass, temperature, entropy and also perform the thermodynamic stability analysis. We see that a string cloud background makes a profound influence on horizon structure, thermodynamic properties and the stability of black holes. Interestingly the entropy of the black hole is unaffected due to a string cloud background. However, the critical solution for thermodynamic stability is being affected by a string cloud background.
TASI Lectures on Supergravity and String Vacua in Various Dimensions
Washington Taylor
2011-04-14T23:59:59.000Z
These lectures aim to provide a global picture of the spaces of consistent quantum supergravity theories and string vacua in higher dimensions. The lectures focus on theories in the even dimensions 10, 8, and 6. Supersymmetry, along with with anomaly cancellation and other quantum constraints, places strong limitations on the set of physical theories which can be consistently coupled to gravity in higher-dimensional space-times. As the dimensionality of space-time decreases, the range of possible supergravity theories and the set of known string vacuum constructions expand. These lectures develop the basic technology for describing a variety of string vacua, including heterotic, intersecting brane, and F-theory compactifications. In particular, a systematic presentation is given of the basic elements of F-theory. In each dimension, we summarize the current state of knowledge regarding the extent to which supergravity theories not realized in string theory can be shown to be inconsistent.
Vortex scattering and intercommuting cosmic strings on a noncommutative spacetime
Joseph, Anosh; Trodden, Mark [Department of Physics, Syracuse University, Syracuse, New York 13244 (United States); Center for Particle Cosmology, Department of Physics and Astronomy, University of Pennsylvania, Pennsylvania 19104 (United States)
2010-02-15T23:59:59.000Z
We study the scattering of noncommutative vortices, based on the noncommutative field theory developed in [A. P. Balachandran, T. R. Govindarajan, G. Mangano, A. Pinzul, B. A. Qureshi, and ?>S. Vaidya, Phys. Rev. D 75, 045009 (2007).], as a way to understand the interaction of cosmic strings. In the center-of-mass frame, the effects of noncommutativity vanish, and therefore the reconnection of cosmic strings occurs in an identical manner to the commutative case. However, when scattering occurs in a frame other than the center-of-mass frame, strings still reconnect but the well-known 90 deg. scattering no longer need correspond to the head-on collision of the strings, due to the breakdown of Lorentz invariance in the underlying noncommutative field theory.
Cloud of strings for radiating black holes in Lovelock gravity
Sushant G. Ghosh; Sunil D. Maharaj
2014-09-28T23:59:59.000Z
We present exact spherically symmetric null dust solutions in the third order Lovelock gravity with a string cloud background in arbitrary $N$ dimensions,. This represents radiating black holes and generalizes the well known Vaidya solution to Lovelock gravity with a string cloud in the background. We also discuss the energy conditions and horizon structures, and explicitly bring out the effect of the string clouds on the horizon structure of black hole solutions for the higher dimensional general relativity and Einstein-Gauss-Bonnet theories. It turns out that the presence of the coupling constant of the Gauss-Bonnet terms and/or background string clouds completely changes the structure of the horizon and this may lead to a naked singularity. We recover known spherically symmetric radiating models as well as static black holes in the appropriate limits.
N=2 String as a Topological Conformal Algebra
J. Gomis; H. Suzuki
1991-11-28T23:59:59.000Z
We prove that critical and subcritical N=2 string theory gives a realization of an N=2 superfield extension of the topological conformal algebra. The essential observation is the vanishing of the background charge.
Effective software testing with a string-constraint solver
Kie?un, Adam
2009-01-01T23:59:59.000Z
This dissertation presents techniques and tools for improving software reliability, by using an expressive string-constraint solver to make implementation-based testing more effective and more applicable. Concolic testing ...
LHC Olympics Workshop and String Phenomenology 2006 Conference
David Gross
2006-10-01T23:59:59.000Z
This is the final report of the organizers of the String Phenomenolgy program of which the LHC Olympics and the String Phenomenolgy conference were a part. In addition, it includes the list of talks from our website which comprise the online proceedings. The KITP no longer publishes conferences proceedings but rather makes recordings and visuals of all talks available on its website at www.kitp.ucsb.edu Program talks are available at http://online.kitp.ucsb.edu/online/strings06/ Conference talks are are at http://online.itp.ucsb.edu/online/strings_c06/ and LHC Olympics talks are at http://online.itp.ucsb.edu/online/lhco_c06/. These talks constitute the proceedings of these meetings.
Regge behavior saves String Theory from causality violations
D'Appollonio, Giuseppe; Russo, Rodolfo; Veneziano, Gabriele
2015-01-01T23:59:59.000Z
Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters $b \\le l_s$ (the string-length parameter) with $l_s \\gg R_p$ (the characteristic scale of the D$p$-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory - and in particular its Regge behavior - is taken into account.
Regge behavior saves String Theory from causality violations
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2015-05-12T23:59:59.000Z
Higher-derivative corrections to the Einstein-Hilbert action are present in bosonic string theory leading to the potential causality violations recently pointed out by Camanho et al. We analyze in detail this question by considering high-energy string-brane collisions at impact parameters $b \\le l_s$ (the string-length parameter) with $l_s \\gg R_p$ (the characteristic scale of the D$p$-brane geometry). If we keep only the contribution of the massless states causality is violated for a set of initial states whose polarization is suitably chosen with respect to the impact parameter vector. Such violations are instead neatly avoided when the full structure of string theory - and in particular its Regge behavior - is taken into account.
Li-Guo Qin; Zhong-Yang Wang; Gong-Wei Lin; Jing-Yun Zhao; Shang-Qing Gong
2013-09-12T23:59:59.000Z
We propose a novel scheme to realize electrically controlled quantum memories in the opto- and electro-mechanical (OEM) cavity. Combining this OEM cavity with the mechanism of Electromagnetically Induced Transparency (EIT) we find that the quantum interference, arising from the two optical transitions of the $\\Lambda$ type three-level atomic ensembles, can be manipulated electrically. Numerical calculations show that the probe photon state can be well stored into the atomic spin state by sending an electric current pulse and retrieved with time-reverse symmetry by sending the other current pulse with opposite direction. The quantum interference with electric controlling is expected to apply to other quantum control aspects.
Gauged Nambu-Jona-Lasinio model and axionic QCD string
Chi Xiong
2014-12-30T23:59:59.000Z
We propose an axionic QCD string scenario based on the original flux-tube model by Kogut and Susskind, and then incorporate it into a gauged Nambu-Jona-Lasinio (NJL) model. Axial anomaly is studied by a new topological coupling from the string side, and by the 't Hooft vortex from the NJL side, respectively. The nontrivial phase distribution of the quark condensate plays an important role in this scenario.
Non-Abelian String of a Finite Length
Monin, Sergey; Yung, Alexei
2015-01-01T23:59:59.000Z
We consider world-sheet theories for non-Abelian strings assuming compactification on a cylinder with a finite circumference $L$ and periodic boundary conditions. The dynamics of the orientational modes is described by two-dimensional CP$(N-1)$ model. We analyze both non-supersymmetric (bosonic) model and ${\\mathcal N}=(2,2)$ supersymmetric CP$(N-1)$ emerging in the case of 1/2-BPS saturated strings in \
Non-Abelian String of a Finite Length
Sergey Monin; Mikhail Shifman; Alexei Yung
2015-05-28T23:59:59.000Z
We consider world-sheet theories for non-Abelian strings assuming compactification on a cylinder with a finite circumference $L$ and periodic boundary conditions. The dynamics of the orientational modes is described by two-dimensional CP$(N-1)$ model. We analyze both non-supersymmetric (bosonic) model and ${\\mathcal N}=(2,2)$ supersymmetric CP$(N-1)$ emerging in the case of 1/2-BPS saturated strings in \
Shooting string holography of jet quenching at RHIC and LHC
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ficnar, Andrej; Gubser, Steven S.; Gyulassy, Miklos
2014-10-13T23:59:59.000Z
We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that Gauss–Bonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.
D-brane effective field theory from string field theory
Washington Taylor
2000-02-15T23:59:59.000Z
Open string field theory is considered as a tool for deriving the effective action for the massless or tachyonic fields living on D-branes. Some simple calculations are performed in open bosonic string field theory which validate this approach. The level truncation method is used to calculate successive approximations to the quartic terms \\phi^4, (A^\\mu A_\\mu)^2 and [A_\\mu, A_\
Stirling number Identities and High energy String Scatterings
Jen-Chi Lee; Yi Yang; Sheng-Lan Ko
2009-09-22T23:59:59.000Z
We use Stirling number identities developed recently in number theory to show that ratios among high energy string scattering amplitudes in the fixed angle regime can be extracted from the Kummer function of the second kind. This result not only brings an interesting bridge between string theory and combinatoric number theory but also sheds light on the understanding of algebraic structure of high energy stringy symmetry.
The squashed fuzzy sphere, fuzzy strings and the Landau problem
Andronache, Stefan
2015-01-01T23:59:59.000Z
We discuss the squashed fuzzy sphere, which is a projection of the fuzzy sphere onto the equatorial plane, and use it to illustrate the stringy aspects of noncommutative field theory. We elaborate explicitly how strings linking its two coincident sheets arise in terms of fuzzy spherical harmonics. In the large N limit, the matrix-model Laplacian is shown to correctly reproduce the semi-classical dynamics of these charged strings, as given by the Landau problem.
High-Energy Scattering vs Static QCD Strings
V. A. Petrov; R. A. Ryutin
2014-09-30T23:59:59.000Z
We discuss the shape of the interaction region of the elastically scattered protons stipulated by the high-energy Pomeron exchange which turns out to be very similar with the shape of the static string representing the confining QCD flux tube. This similarity disappears when we enter the LHC energy region, which corresponds to many-Pomeron exchanges. Reversing the argument we conjecture a modified relationship between the width and the length of the confining string at very large lengths.
Self-avoiding effective strings in lattice gauge theories
M. Caselle; F. Gliozzi
1991-11-28T23:59:59.000Z
It is shown that the effective string recently introduced to describe the long distance dynamics of 3D gauge systems in the confining phase has an intriguing description in terms of models of 2D self-avoiding walks in the dense phase. The deconfinement point, where the effective string becomes N=2 supersymmetric, may then be interpreted as the tricritical Theta point where the polymer chain undergoes a collapse transition. As a consequence, a universal value of the deconfinement temperature is predicted.
Fusion of strings and cosmic rays at ultrahigh energies
N. Armesto; M. A. Braun; E. G. Ferreiro; C. Pajares; Yu. M. Shabelski
1996-02-13T23:59:59.000Z
It is shown that the fusion of strings is a source of particle production in nucleus--nucleus collisions outside the kinematical limits of nucleon--nucleon collisions. This fact, together with another effect of string fusion, the reduction of multiplicities, sheds some light on two of the main problems of ultrahigh energy cosmic rays, the chemical composition and the energy of the most energetic detected cosmic rays.
Shooting String Holography of Jet Quenching at RHIC and LHC
Andrej Ficnar; Steven S. Gubser; Miklos Gyulassy
2014-11-07T23:59:59.000Z
We derive a new formula for jet energy loss using finite endpoint momentum shooting strings initial conditions in SYM plasmas to overcome the difficulties of previous falling string holographic scenarios. We apply the new formula to compute the nuclear modification factor RAA and the elliptic flow parameter v2 of light hadrons at RHIC and LHC. We show furthermore that Gauss-Bonnet quadratic curvature corrections to the AdS5 geometry improve the agreement with the recent data.
Counting Strings and Phase Transitions in 2D QCD
W. Taylor
1994-05-03T23:59:59.000Z
Several string theories related to QCD in two dimensions are studied. For each of these theories the large $N$ free energy on a (target) sphere of area $A$ is calculated. By considering theories with different subsets of the geometrical structures involved in the full QCD${}_2$ string theory, the different contributions of these structures to the string free energy are calculated using both analytic and numerical methods. The equivalence between the leading terms in the $SU(N)$ and $U(N)$ free energies is simply demonstrated from the string formulation. It is shown that when $\\Omega$-points are removed from the theory, the free energy is convergent for small and large values of $A$ but divergent in an intermediate range. Numerical results indicate that the free energy for the full QCD${}_2$ string fails to converge at the Douglas-Kazakov phase transition point. Similar results for a single chiral sector of the theory, such as has recently been studied by Cordes, Moore, and Ramgoolam, indicate that there are three distinct phases in that theory. These results indicate that from the point of view of the strong coupling phase, the phase transition in the full QCD${}_2$ string arises from the entropy of branch-point singularities.
Storage and Retrieval of Thermal Light in Warm Atomic Vapor
Young-Wook Cho; Yoon-Ho Kim
2010-07-12T23:59:59.000Z
We report slowed propagation and storage and retrieval of thermal light in warm rubidium vapor using the effect of electromagnetically-induced transparency (EIT). We first demonstrate slowed-propagation of the probe thermal light beam through an EIT medium by measuring the second-order correlation function of the light field using the Hanbury-Brown$-$Twiss interferometer. We also report an experimental study on the effect of the EIT slow-light medium on the temporal coherence of thermal light. Finally, we demonstrate the storage and retrieval of thermal light beam in the EIT medium. The direct measurement of the photon number statistics of the retrieved light field shows that the photon number statistics is preserved during the storage and retrieval process.
Content-Based Hyperspectral Image Retrieval Using Spectral Unmixing
Plaza, Antonio J.
, Avda. de la Universidad s/n 10071 CÂ´aceres, Spain ABSTRACT The purpose of content-based image retrieval weeks of September, 2001, only a few days after the terrorist attacks that collapsed the two main towers
A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres
Madhusudhan, Nikku
We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of one-dimensional (1D) atmosphere models in order to cover the large ...
Multimedia Content Analysis, Management and Retrieval: Trends and Challenges
Sebe, Nicu
Multimedia Content Analysis, Management and Retrieval: Trends and Challenges Alan Hanjalica , Nicu, communications and storage technology have made multimedia data become prevalent. Multimedia has gained enormous content of multimedia data, built through the synergies of the information contained in different
Restructuring Sparse High Dimensional Data for Effective Retrieval
Isbell, Charles
1998-05-01T23:59:59.000Z
The task in text retrieval is to find the subset of a collection of documents relevant to a user's information request, usually expressed as a set of words. Classically, documents and queries are represented as vectors ...
Hanford Site Shares Lessons Learned in Retrieving Highly Radioactive...
Office of Environmental Management (EM)
that will be used to retrieve highly radioactive sludge at the Hanford site. This pump was modified to fit the underwater environment where the sludge is stored. A team from...
Catch Tank 241-C-301 Retrieval Feasibility Study Prepared by...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
U.S. Department of Energy, Richland, Washington. ORP- 11242, River Protection Project System Plan - Retrieve and Treat Hanford's Tank Waste and Close the Tank Farms to Protect the...
PIRMAP: Efficient Private Information Retrieval for MapReduce
International Association for Cryptologic Research (IACR)
evaluation shows that non-trivial PIR such as PIRMAP can be more than one order of magnitude cheaper, and what risks the leakage may incur. Private Information Retrieval (PIR) offers a solution
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Cadeddu, Maria
Microwave Radiometer data (MWR Profiles - QME), water vapor, temp, cloud liquid water, precip water retrievals
New Techniques and Technologies for Information Retrieval and Knowledge Extraction from Nuclear Fusion Massive Databases
SNF fuel retrieval sub project safety analysis document
BERGMANN, D.W.
1999-02-24T23:59:59.000Z
This safety analysis is for the SNF Fuel Retrieval (FRS) Sub Project. The FRS equipment will be added to K West and K East Basins to facilitate retrieval, cleaning and repackaging the spent nuclear fuel into Multi-Canister Overpack baskets. The document includes a hazard evaluation, identifies bounding accidents, documents analyses of the accidents and establishes safety class or safety significant equipment to mitigate accidents as needed.
Visualizing and improving the robustness of phase retrieval algorithms
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tripathi, Ashish; Leyffer, Sven; Munson, Todd; Wild, Stefan M.
2015-06-01T23:59:59.000Z
Coherent x-ray diffractive imaging is a novel imaging technique that utilizes phase retrieval and nonlinear optimization methods to image matter at nanometer scales. We explore how the convergence properties of a popular phase retrieval algorithm, Fienup's HIO, behave by introducing a reduced dimensionality problem allowing us to visualize and quantify convergence to local minima and the globally optimal solution. We then introduce generalizations of HIO that improve upon the original algorithm's ability to converge to the globally optimal solution.
The Wavelet Trie: Maintaining an Indexed Sequence of Strings in Compressed Space
Grossi, Roberto
2012-01-01T23:59:59.000Z
An indexed sequence of strings is a data structure for storing a string sequence that supports random access, searching, range counting and analytics operations, both for exact matches and prefix search. String sequences lie at the core of column-oriented databases, log processing, and other storage and query tasks. In these applications each string can appear several times and the order of the strings in the sequence is relevant. The prefix structure of the strings is relevant as well: common prefixes are sought in strings to extract interesting features from the sequence. Moreover, space-efficiency is highly desirable as it translates directly into higher performance, since more data can fit in fast memory. We introduce and study the problem of compressed indexed sequence of strings, representing indexed sequences of strings in nearly-optimal compressed space, both in the static and dynamic settings, while preserving provably good performance for the supported operations. We present a new data structure for...
An SL(2,Z) Multiplet of Type IIB Superstrings
John H. Schwarz
1997-06-10T23:59:59.000Z
An SL(2, Z) family of string solutions of type IIB supergravity in ten dimensions is constructed. The solutions are labeled by a pair of relatively prime integers, which characterize charges of the three-form field strengths. The string tensions depend on these charges in an SL(2, Z) covariant way. Compactifying on a circle and identifying with eleven-dimensional supergravity compactified on a torus implies that the modulus of the IIB theory should be equated to the modular parameter of the torus.
Cloud Property Retrieval Products for Graciosa Island, Azores
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Dong, Xiquan
The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.
Cloud Property Retrieval Products for Graciosa Island, Azores
Dong, Xiquan
2014-05-05T23:59:59.000Z
The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.
Jacobi Forms of Higher Index and Paramodular Groups in N=2, D=4 Compactifications of String Theory
Caner Nazaroglu
2013-09-25T23:59:59.000Z
We associate a Jacobi form over a rank s lattice to N=2, D=4 heterotic string compactifications which have s Wilson lines at a generic point in the vector multiplet moduli space. Jacobi forms of index m=1 and m=2 have appeared earlier in the context of threshold corrections to heterotic string couplings. We emphasize that higher index Jacobi forms as well as Jacobi forms of several variables over more generic even lattices also appear and construct models in which they arise. In particular, we construct an orbifold model which can be connected to models that give index m=3, 4 or 5 Jacobi forms through the Higgsing process. Constraints from being a Jacobi form are then employed to get threshold corrections using only partial information on the spectrum. We apply this procedure for index m=3, 4 or 5 Jacobi form examples and also for Jacobi forms over A_2 and A_3 root lattices. Examples with a single Wilson line are examined in detail and we display the relation of Siegel forms over a paramodular group \\Gamma_m to these models, where \\Gamma_m is associated with the T-duality group of the models we study. Finally, results on the heterotic string side are used to clarify the linear mapping of vector multiplet moduli to Type IIA duals without using the one-loop cubic part of the prepotential on the Type II side, and also to give predictions for the geometry of the dual Calabi-Yau manifolds.
String GUT scenarios with stabilized moduli
Blumenhagen, Ralph; Moster, Sebastian; Plauschinn, Erik [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany)
2008-09-15T23:59:59.000Z
Taking into account the recently proposed poly-instanton corrections to the superpotential and combining the racetrack with a Kachru-Kallosh-Linde-Trivedi, respectively, large volume scenario in an intricate manner, we show that we gain exponential control over the parameters in an effective superpotential. This allows us to dynamically stabilize moduli such that a conventional minimal supersymmetric standard model scenario with the string scale lowered to the grand unified theory scale is realized. Depending on the cycles wrapped by the minimal supersymmetric standard model branes, two different scenarios for the hierarchy of soft masses arise. The first one is a supergravity mediated model with M{sub 3/2}{approx_equal}1 TeV while the second one features mixed anomaly supergravity mediation with M{sub 3/2}{approx_equal}10{sup 10} GeV and split supersymmetry. We also comment on dynamically lowering the scales such that the tree level cosmological constant is of the order {lambda}=(10{sup -3} eV){sup 4}.
Integrable Deformations of Strings on Symmetric Spaces
Timothy J. Hollowood; J. Luis Miramontes; David M. Schmidtt
2014-07-16T23:59:59.000Z
A general class of deformations of integrable sigma-models with symmetric space F/G target-spaces are found. These deformations involve defining the non-abelian T dual of the sigma-model and then replacing the coupling of the Lagrange multiplier imposing flatness with a gauged F/F WZW model. The original sigma-model is obtained in the limit of large level. The resulting deformed theories are shown to preserve both integrability and the equations-of-motion, but involve a deformation of the symplectic structure. It is shown that this deformed symplectic structure involves a linear combination of the original Poisson bracket and a generalization of the Faddeev-Reshetikhin Poisson bracket which we show can be re-expressed as two decoupled F current algebras. It is then shown that the deformation can be incorporated into the classical model of strings on R x F/G via a generalization of the Pohlmeyer reduction. In this case, in the limit of large sigma-model coupling it is shown that the theory becomes the relativistic symmetric space sine-Gordon theory. These results point to the existence of a deformation of this kind for the full Green-Schwarz superstring on AdS5 x S5.
Condorcet Fusion for Improved Retrieval # Mark Montague
Aslam, Javed
. Metasearch o#ers a system # This work generously supported by NSF grants EIA 9802068, BCS9978116 of documents. atic way of incorporating all of the various types of evidence available to a search engine
Mescalero Apache Tribe Monitored Retrievable Storage (MRS)
Peso, F.
1992-03-13T23:59:59.000Z
The Nuclear Waste Policy Act of 1982, as amended, authorizes the siting, construction and operation of a Monitored Retrievable Storage (MRS) facility. The MRS is intended to be used for the temporary storage of spent nuclear fuel from the nation's nuclear power plants beginning as early as 1998. Pursuant to the Nuclear Waste Policy Act, the Office of the Nuclear Waste Negotiator was created. On October 7, 1991, the Nuclear Waste Negotiator invited the governors of states and the Presidents of Indian tribes to apply for government grants in order to conduct a study to assess under what conditions, if any, they might consider hosting an MRS facility. Pursuant to this invitation, on October 11, 1991 the Mescalero Apache Indian Tribe of Mescalero, NM applied for a grant to conduct a phased, preliminary study of the safety, technical, political, environmental, social and economic feasibility of hosting an MRS. The preliminary study included: (1) An investigative education process to facilitate the Tribe's comprehensive understanding of the safety, environmental, technical, social, political, and economic aspects of hosting an MRS, and; (2) The development of an extensive program that is enabling the Tribe, in collaboration with the Negotiator, to reach an informed and carefully researched decision regarding the conditions, (if any), under which further pursuit of the MRS would be considered. The Phase 1 grant application enabled the Tribe to begin the initial activities necessary to determine whether further consideration is warranted for hosting the MRS facility. The Tribe intends to pursue continued study of the MRS in order to meet the following objectives: (1) Continuing the education process towards a comprehensive understanding of the safety, environmental, technical, social and economic aspects of the MRS; (2) Conducting an effective public participation and information program; (3) Participating in MRS meetings.
Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole
Qian, Yachao
2015-01-01T23:59:59.000Z
We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.
Streched String with Self-Interaction at the Hagedorn Point: Spatial Sizes and Black Hole
Yachao Qian; Ismail Zahed
2015-08-15T23:59:59.000Z
We analyze the length, mass and spatial distribution of a discretized transverse string in $D_\\perp$ dimensions with fixed end-points near its Hagedorn temperature. We suggest that such a string may dominate the (holographic) Pomeron kinematics for dipole-dipole scattering at intermediate and small impact parameters. Attractive self-string interactions cause the transverse string size to contract away from its diffusive size, a mechanism reminiscent of the string-black-hole transmutation. The string shows sizable asymmetries in the transverse plane that translate to primordial azimuthal asymmetries in the stringy particle production in the Pomeron kinematics for current pp and pA collisions at collider energies.
SLUDGE RETRIEVAL FROM HANFORD K WEST BASIN SETTLER TANKS
ERPENBECK EG; LESHIKAR GA
2011-01-13T23:59:59.000Z
In 2010, an innovative, remotely operated retrieval system was deployed to successfully retrieve over 99.7% of the radioactive sludge from ten submerged tanks in Hanford's K-West Basin. As part of K-West Basin cleanup, the accumulated sludge needed to be removed from the 0.5 meter diameter by 5 meter long settler tanks and transferred approximately 45 meters to an underwater container for sampling and waste treatment. The abrasive, dense, non-homogeneous sludge was the product of the washing process of corroded nuclear fuel. It consists of small (less than 600 micron) particles of uranium metal, uranium oxide, and various other constituents, potentially agglomerated or cohesive after 10 years of storage. The Settler Tank Retrieval System (STRS) was developed to access, mobilize and pump out the sludge from each tank using a standardized process of retrieval head insertion, periodic high pressure water spray, retraction, and continuous pumping of the sludge. Blind operations were guided by monitoring flow rate, radiation levels in the sludge stream, and solids concentration. The technology developed and employed in the STRS can potentially be adapted to similar problematic waste tanks or pipes that must be remotely accessed to achieve mobilization and retrieval of the sludge within.
Testing Problem Solving in Ravens: String-Pulling to Reach Food Bernd Heinrich & Thomas Bugnyar
Indiana University
the string to lift the meat. A second group of birds with similar exposure to strings but without any Bugnyar, Konrad Lorenz Research Station and Department of Behaviour, Neurobiology, and Cognition
A New Lorentz Violating Nonlocal Field Theory From String-Theory
Ganor, Ori J.
2009-01-01T23:59:59.000Z
hep-th/9908019]. [29] J. Polchinski, “String theory. Vol.2: Superstring theory and beyond,” [30] S. Chakravarty, K.Violating Nonlocal Field Theory From String-Theory Ori J.
Jet signals for low mass strings at the LHC
Luis A. Anchordoqui; Haim Goldberg; Satoshi Nawata; Tomasz R. Taylor
2008-04-22T23:59:59.000Z
The mass scale M_s of superstring theory is an arbitrary parameter that can be as low as few TeVs if the Universe contains large extra dimensions. We propose a search for the effects of Regge excitations of fundamental strings at LHC, in the process p p \\to \\gamma jet. The underlying parton process is dominantly the single photon production in gluon fusion, g g \\to \\gamma g, with open string states propagating in intermediate channels. If the photon mixes with the gauge boson of the baryon number, which is a common feature of D-brane quivers, the amplitude appears already at the string disk level. It is completely determined by the mixing parameter -- and it is otherwise model-(compactification-) independent. Even for relatively small mixing, 100 fb^{-1} of LHC data could probe deviations from standard model physics, at a 5\\sigma significance, for M_s as large as 3.3 TeV.
Solution of the string equations for asymmetric potentials
Patrick Waters
2015-06-22T23:59:59.000Z
We consider the large $N$ expansion of the partition function for the Hermitian one-matrix model. It is well known that the coefficients of this expansion are generating functions $F^{(g)}$ for a certain kind of graph embedded in a Riemann surface. Other authors have made a simplifying assumption that the potential $V$ is an even function. We present a method for computing $F^{(g)}$ in the case that $V$ is not an even function. Our method is based on the string equations, and yields "valence independent" formulas which do not depend explicitly on the potential. We introduce a family of differential operators, the "string polynomials", which make clear the valence independent nature of the string equations.
Clouds of strings in third-order Lovelock gravity
Sushant G. Ghosh; Uma Papnoi; Sunil D. Maharaj
2014-08-20T23:59:59.000Z
Lovelock theory is a natural extension of the Einstein theory of general relativity to higher dimensions in which the first and second orders correspond, respectively, to general relativity and Einstein-Gauss-Bonnet gravity. We present exact black hole solutions of $D\\geq 4$-dimensional spacetime for first-, second-, and third-order Lovelock gravities in a string cloud background. Further, we compute the mass, temperature, and entropy of black hole solutions for the higher-dimensional general relativity and Einstein-Gauss-Bonnet theories and also perform thermodynamic stability of black holes. It turns out that the presence of the Gauss-Bonnet term 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. We rediscover several known spherically symmetric black hole solutions in the appropriate limits.
Axion inflation and gravity waves in string theory
Kallosh, Renata; Sivanandam, Navin; Soroush, Masoud [Institute for Theoretical Physics, Department of Physics, Stanford University, Stanford, California 94305-4060 (United States)
2008-02-15T23:59:59.000Z
The majority of models of inflation in string theory predict an absence of measurable gravitational waves, r<<10{sup -3}. The most promising proposals for making string theoretic models that yield measurable tensor fluctuations involve axion fields with slightly broken shift symmetry. We consider such models in detail, with a particular focus on the N-flation scenario and on axion valley/natural inflation models. We find that in Calabi-Yau threefold compactifications with logarithmic Kaehler potentials K it appears to be difficult to meet the conditions required for axion inflation in the supergravity regime. However, in supergravities with an (approximately) quadratic shift-symmetric K, axion inflation may be viable. Such Kaehler potentials do arise in some string models, in specific limits of the moduli space. We describe the most promising classes of models; more detailed study will be required before one can conclude that working models exist.
Theoretical Research in Cosmology, High-Energy Physics and String Theory
Ng, Y Jack; Dolan, Louise; Mersini-Houghton, Laura; Frampton, Paul
2013-07-29T23:59:59.000Z
The research was in the area of Theoretical Physics: Cosmology, High-Energy Physics and String Theory
Instability of Axions and Photons In The Presence of Cosmic Strings
Eduardo I. Guendelman; Idan Shilon
2008-10-26T23:59:59.000Z
We report that axions and photons exhibit instability in the presence of cosmic strings that are carrying magnetic flux in their core. The strength of the instability is determined by the symmetry breaking scale of the cosmic string theory. This result would be evident in gamma ray bursts and axions emanating from the cosmic string. These effects will eventually lead to evaporation of the cosmic string.
Bannister, R.; Rhoden, G.; Davies, G.B. [BNFL, Inc., Englewood, CO (United States)
1995-09-01T23:59:59.000Z
Since 1970, the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory has accepted over 55,000 cubic meters of Transuranic contaminated hazardous waste for interim storage. The waste has been neatly stored in ``cell`` configurations on adjoining, above ground asphalt pads at the Transuranic Storage Area (TSA). A number of reports have been supplied for review and comment describing the methodology and equipment proposed for retrieval of drums and boxes from a storage facility at the INEL site. The contract for this review requires two main issues to be addressed. First, the adequacy of equipment and methodology for the retrieval of containers which have been breached, lost structural integrity, or are otherwise damaged, Second, to review the strategies and equipment for retrieval of intact waste containers. These issues are presented in the following report along with additional detail in the methodology to complete the description of the operations required for retrieval under most operational scenarios. The documentation reviewed is considered to be at an interim stage and is therefore expected to be subject to the development of the methodology from the existing level of detail with input from the facility operators. This review aims to anticipate some of this development by providing suggested detailed methods of retrieval and equipment for both normal and abnormal operations.
Hybrid MSW + VO Solution of the Solar Neutrino Problem in String-Motivated Unified Theories
Allanach, Benjamin C; Petcov, S T
1998-01-01T23:59:59.000Z
It is shown that the hybrid MSW + VO solution of the solar neutrino problem, according to which the solar nu_e undergo matter-enhanced transitions into nu_mu, nu_tau in the Sun followed by long wave length (about 1.5 10^8 km) nu_e -> nu_mu, nu_tau oscillations in vacuum between the Sun and the Earth, can occur naturally in string-motivated grand unified theories. We consider the supersymmetric version of a string-type SU(4)xSU(2)_LxSU(2)_R theory with U(1)_X family symmetry, which was shown to successfully describe the charged fermion masses and the quark mixing, and extend the earlier fermion mass analysis to the neutrino sector. We show that the four oscillation parameters Delta m_31^2, Delta m_21^2 and sin^2 2 theta_12, sin^2 2 theta_13, characterising the combined matter-enhanced transitions and vacuum oscillations of the solar nu_e, naturally get values in the ranges of the hybrid MSW + VO solutions found recently.
Hybrid MSW + VO Solution of the Solar Neutrino Problem in String-Motivated Unified Theories
B. C. Allanach; G. K. Leontaris; S. T. Petcov
1997-12-19T23:59:59.000Z
It is shown that the hybrid MSW + VO solution of the solar neutrino problem, according to which the solar nu_e undergo matter-enhanced transitions into nu_mu, nu_tau in the Sun followed by long wave length (about 1.5 10^8 km) nu_e -> nu_mu, nu_tau oscillations in vacuum between the Sun and the Earth, can occur naturally in string-motivated grand unified theories. We consider the supersymmetric version of a string-type SU(4)xSU(2)_LxSU(2)_R theory with U(1)_X family symmetry, which was shown to successfully describe the charged fermion masses and the quark mixing, and extend the earlier fermion mass analysis to the neutrino sector. We show that the four oscillation parameters Delta m_31^2, Delta m_21^2 and sin^2 2 theta_12, sin^2 2 theta_13, characterising the combined matter-enhanced transitions and vacuum oscillations of the solar nu_e, naturally get values in the ranges of the hybrid MSW + VO solutions found recently.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Huang, Lei; Zuo, Chao; Idir, Mourad; Qu, Weijuan; Asundi, Anand
2015-01-01T23:59:59.000Z
A novel transport-of-intensity equation (TIE) based phase retrieval method is proposed with putting an arbitrarily-shaped aperture into the optical wavefield. In this arbitrarily-shaped aperture, the TIE can be solved under non-uniform illuminations and even non-homogeneous boundary conditions by iterative discrete cosine transforms with a phase compensation mechanism. Simulation with arbitrary phase, arbitrary aperture shape, and non-uniform intensity distribution verifies the effective compensation and high accuracy of the proposed method. Experiment is also carried out to check the feasibility of the proposed method in real measurement. Comparing to the existing methods, the proposed method is applicable for any types of phasemore »distribution under non-uniform illumination and non-homogeneous boundary conditions within an arbitrarily-shaped aperture, which enables the technique of TIE with hard aperture become a more flexible phase retrieval tool in practical measurements.« less
Generalized dilaton-Maxwell cosmic string and wall solutions
John Morris
2006-08-15T23:59:59.000Z
The class of static solutions found by Gibbons and Wells for dilaton-electrodynamics in flat spacetime, which describe nontopological strings and walls that trap magnetic flux, is extended to a class of dynamical solutions supporting arbitrarily large, nondissipative traveling waves, using techniques previously applied to global and local topological defects. These solutions can then be used in conjunction with S-duality to obtain more general solitonic solutions for various axidilaton-Maxwell theories. As an example, a set of dynamical solutions is found for axion, dilaton, and Maxwell fields in low energy heterotic string theory using the SL(2,R) invariance of the equations of motion.
Note on Structure Formation from Cosmic String Wakes
Duplessis, Francis
2013-01-01T23:59:59.000Z
The search for cosmic strings has been of renewed interest with the advent of precision cosmology. In this note we give a quantitative description of the nonlinear matter density fluctuations that can form from a scaling network of cosmic string wakes. Specifically, we compute the distribution of dark matter halos. These halos would possess strong correlations in position space that should have survived until today. We also discuss the challenges involved in their detection due to their small size and the complex dynamics of their formation.
Coset Symmetries in Dimensionally Reduced Bosonic String Theory
N. D. Lambert; P. C. West
2001-08-02T23:59:59.000Z
We discuss the dimensional reduction of various effective actions, particularly that of the closed Bosonic string and pure gravity, to two and three dimensions. The result for the closed Bosonic string leads to coset symmetries which are in agreement with those recently predicted and argued to be present in a new unreduced formulation of this theory. We also show that part of the Geroch group appears in the unreduced duality symmetric formulation of gravity recently proposed. We conjecture that this formulation can be extended to a non-linear realisation based on a Kac-Moody algebra which we identify. We also briefly discuss the proposed action of Bosonic M-theory.
Anyonic glueballs from an effective-string model
Buisseret, Fabien
2015-01-01T23:59:59.000Z
Relying on an effective-string approach in which glueballs --- bound states of pure Yang-Mills theory --- are modelled by closed strings, we give arguments suggesting that anyonic glueballs, \\textit{i.e.} glueballs with arbitrary spin, may exist in $(2+1)$-$\\,$dimensional Yang-Mills theory. We then focus on the large$\\,$-$N_c$ limit of $SU$($N_c$) Yang-Mills theory and show that our model leads to a mass spectrum in good agreement with lattice data in the scalar sector, while it predicts the masses and spins of anyonic glueball states.
Physical Interpretation of the 26 Dimensions of Bosonic String Theory
Frank D. Smith Jr
2002-07-15T23:59:59.000Z
The 26 dimensions of Closed Unoriented Bosonic String Theory are interpreted as the 26 dimensions of the traceless Jordan algebra J3(O)o of 3x3 Octonionic matrices, with each of the 3 Octonionic dimenisons of J3(O)o having the following physical interpretation: 4-dimensional physical spacetime plus 4-dimensional internal symmetry space; 8 first-generation fermion particles; 8 first-generation fermion anti-particles. This interpretation is consistent with interpreting the strings as World Lines of the Worlds of Many-Worlds Quantum Theory and the 26 dimensions as the degrees of freedom of the Worlds of the Many-Worlds.
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2008-10-10T23:59:59.000Z
are then described as the exchanges of gauge bosons in an SU(3)×SU(2)×U(1) symmetry group. The Standard Model is quite successful in explaining the experimental data, and in fact it agrees with all of our observations of the physical world. However, a major problem..., string theory has been deemed to be a very promising can- didate for the unification theory of everything. The spectrum of bosonic particles may be explained as the various excitations of strings, and this spectrum automat- ically contains a massless spin...
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2009-05-15T23:59:59.000Z
are then described as the exchanges of gauge bosons in an SU(3)?SU(2)?U(1) symmetry group. The Standard Model is quite successful in explaining the experimental data, and in fact it agrees with all of our observations of the physical world. However, a major problem..., string theory has been deemed to be a very promising can- didate for the unification theory of everything. The spectrum of bosonic particles may be explained as the various excitations of strings, and this spectrum automat- ically contains a massless spin...
Sister trajectories and locality in multiloop string scattering
Carbon, S.L. (ACTA Inc., 505 N. Orlando Avenue, Mez 3, Cocoa Beach, Florida 32931 (United States))
1995-04-15T23:59:59.000Z
The multiloop corrections to the high energy behavior of four-tachyon scattering are studied in string theory. In the limit of high center-of-mass energy, [ital s][r arrow][infinity], for fixed transfer momentum squared, [ital t], we obtain the Regge behavior of the first sister'' trajectory in two-loop scattering. The multiloop-generated sisters are found to be independent of propagator twists, which are necessary for exposing tree-level sisters. The presence of these trajectories in higher order loop diagrams may be sufficient for string theory to be consistent nonperturbatively with locality.
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2009-05-15T23:59:59.000Z
are then described as the exchanges of gauge bosons in an SU(3)?SU(2)?U(1) symmetry group. The Standard Model is quite successful in explaining the experimental data, and in fact it agrees with all of our observations of the physical world. However, a major problem..., string theory has been deemed to be a very promising can- didate for the unification theory of everything. The spectrum of bosonic particles may be explained as the various excitations of strings, and this spectrum automat- ically contains a massless spin...
Kerr-NUT-AdS metrics and string theory
Chen, Wei
2008-10-10T23:59:59.000Z
are then described as the exchanges of gauge bosons in an SU(3)×SU(2)×U(1) symmetry group. The Standard Model is quite successful in explaining the experimental data, and in fact it agrees with all of our observations of the physical world. However, a major problem..., string theory has been deemed to be a very promising can- didate for the unification theory of everything. The spectrum of bosonic particles may be explained as the various excitations of strings, and this spectrum automat- ically contains a massless spin...
Quantum Charged Non-Linear Nano-String and Quantum Vacuum
F. Kheirandish; M. Amooshahi
2005-07-20T23:59:59.000Z
The classical and quantum dynamic of a nonlinear chareged vibrating string and its interaction with quantum vacuum field is investigated. Some probability amplitudes for transitions between vacuum field and quantum states of the string are obtained. The effect of nonlinearity on some probability amplitudes is investigated and finally the corect equation for string containing the vacuum and radiation reaction field is obtained.
MUS420/EE367A Lecture 7B Digital Waveguide Modeling of Bowed Strings
Smith III, Julius Orion
= Friction Curve × Differential Velocity Reaction Force = String Wave Impedance × Velocity Change · Nominally StringBow Bow Velocity (Primary Control) Bow Force Bow Position BridgeString-1 Nut or Finger Lowpass Body into two sections · Bow junction = nonlinear two-port · Primary control variable = bow velocity velocity
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP
Song, Siang Wun
Parallel Dynamic Programming for Solving the String Editing Problem on a CGM/BSP C. E. R. Alves, string editing, dynamic programming, CGM, BSP # Partially supported by CNPq and FINEPPRONEXSAI Proc. No. net ABSTRACT In this paper we present a coarsegrained parallel algorithm for solving the string edit
Quantization of Dyon Charge and Electric-Magnetic Duality in String Theory
Ashoke Sen
1992-09-05T23:59:59.000Z
We analyze the allowed spectrum of electric and magnetic charges carried by dyons in (toroidally compactified) heterotic string theory in four dimensions at arbitrary values of the string coupling constant and $\\theta$ angle. The spectrum is shown to be invariant under electric-magnetic duality transformation, thereby providing support to the conjecture that this is an exact symmetry in string theory.
On the short string limit of the folded spinning string in AdS5 x S5
M. Beccaria; A. Tirziu
2008-10-23T23:59:59.000Z
In this paper we generalize the results of arXiv:0806.4758 to non-zero value J of angular momentum in S^5. We compute the 1-loop correction to the energy of the folded spinning string in AdS_5 x S^5 in the particular limit of slow short string approximation. In this limit the string is moving in a near-flat central region of AdS_5 slowly rotating in both AdS_5 and S^5. The one-loop correction should represent the first subleading correction to strong coupling expansion of the anomalous dimension of short gauge theory operators of the form Tr D^S Z^J in the SL(2) sector.
Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals
Shupe, Matthew
2013-05-22T23:59:59.000Z
Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.
Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Shupe, Matthew
Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.
Recognition, indexing and retrieval of British broadcast news with the THISL system.
Robinson, Tony; Abberley, Dave; Kirby, David; Renals, Steve
1999-01-01T23:59:59.000Z
This paper described the THISL spoken document retrieval system for British and North American Broadcast News. The system is based on the ABBOT large vocabulary speech recognizer and a probabilistic text retrieval system. ...
Delene, David J.
` Relationship between Cloud Condensation Nuclei and Satellite Retrievals of Cloud Droplet is the relationship between below cloud base cloud condensation nuclei (CCN) and satellite retrievals of cloud droplet cloud effective radius; however, satellites can not measure cloud condensation nuclei (CCN
Retrieval of Non-Spherical Dust Aerosol Properties from Satellite Observations
Huang, Xin
2013-08-01T23:59:59.000Z
An accurate and generalized global retrieval algorithm from satellite observations is a prerequisite to understand the radiative effect of atmospheric aerosols on the climate system. Current operational aerosol retrieval algorithms are limited...
The Effect of Detail on Controlled Retrieval Processes in Recollection Memory
Small, Nicola
2012-03-14T23:59:59.000Z
The aim of this study was to further explore the basic mechanisms of the episodic memory search process. This included looking at the content of what was encoded and retrieved and the processes behind this encoding and retrieval. Some theories...
Scalar Perturbations in a String Inspired Inflationary Scenario
C. E. M. Batista; J. C. Fabris
1996-02-28T23:59:59.000Z
We consider an inflationary model inspired in the low energy limit of string theory. In this model, the scale factor grows exponentially with time. A perturbation study is performed, and we show that there is a mode which displays an exponential growth in the perturbation of the scalar field.
The vacuum state functional of interacting string field theory
A. Ilderton
2005-06-21T23:59:59.000Z
We show that the vacuum state functional for both open and closed string field theories can be constructed from the vacuum expectation values it must generate. The method also applies to quantum field theory and as an application we give a diagrammatic description of the equivalance between Schrodinger and covariant repreresentations of field theory.
Combinatorial Problems on Strings with Applications to Protein Folding
Newman, Alantha
Combinatorial Problems on Strings with Applications to Protein Folding Alantha Newman MIT San Jose, CA 95120, USA ruhl@almaden.ibm.com Abstract We consider the problem of protein folding in linear time. 1 Introduction We consider the problem of protein folding in the HP model on the three
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey
Storkey, Amos
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey School of Informatics 5 Forrest- portion of the records potentially of inter- est to a given astronomer. We have devel- oped renewal- veys are carried out in all wavelength ranges, from high energy gamma rays to the longest wavelength ra
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey #
Storkey, Amos
Renewal Strings for Cleaning Astronomical Databases Amos J. Storkey # School of Informatics 5 portion of the records potentially of inter est to a given astronomer. We have devel oped renewal veys are carried out in all wavelength ranges, from high energy gamma rays to the longest wavelength ra
HBT puzzle at RHIC AMPT model with String Melting
Lin, Zi-wei
/RsideSmall radii Small duration time dt by Stephen Johnson at RWW02 One way out: Hydro Softest point in EOS Measured extensively in heavy ion collisions reasonably described by models (hydro-ph/01120062 recent hydro studies: #12;HIJING energy in strings(soft) and minijet partons(hard) ZPC (Zhang
String Organization of Field Theories: Duality and Gauge Invariance
Y. J. Feng; C. S. Lam
1994-09-14T23:59:59.000Z
String theories should reduce to ordinary four-dimensional field theories at low energies. Yet the formulation of the two are so different that such a connection, if it exists, is not immediately obvious. With the Schwinger proper-time representation, and the spinor helicity technique, it has been shown that field theories can indeed be written in a string-like manner, thus resulting in simplifications in practical calculations, and providing novel insights into gauge and gravitational theories. This paper continues the study of string organization of field theories by focusing on the question of local duality. It is shown that a single expression for the sum of many diagrams can indeed be written for QED, thereby simulating the duality property in strings. The relation between a single diagram and the dual sum is somewhat analogous to the relation between a old- fashioned perturbation diagram and a Feynman diagram. Dual expressions are particularly significant for gauge theories because they are gauge invariant while expressions for single diagrams are not.
Grand Unification as a Bridge Between String Theory and Phenomenology
Pati, Jogesh C.
2006-06-09T23:59:59.000Z
In the first part of the talk, I explain what empirical evidence points to the need for having an effective grand unification-like symmetry possessing the symmetry SU(4)-color in 4D. If one assumes the premises of a future predictive theory including gravity--be it string/M theory or a reincarnation--this evidence then suggests that such a theory should lead to an effective grand unification-like symmetry as above in 4D, near the string-GUT-scale, rather than the standard model symmetry. Advantages of an effective supersymmetric G(224) = SU(2){sub L} x SU(2){sub R} x SU(4){sup c} or SO(10) symmetry in 4D in explaining (1) observed neutrino oscillations, (2) baryogenesis via leptogenesis, and (3) certain fermion mass-relations are noted. And certain distinguishing tests of a SUSY G(224) or SO(10)-framework involving CP and flavor violations (as in {mu} {yields} e{gamma}, {tau} {yields} {mu}{gamma}, edm's of the neutron and the electron) as well as proton decay are briefly mentioned. Recalling some of the successes we have had in our understanding of nature so far, and the current difficulties of string/M theory as regards the large multiplicity of string vacua, some comments are made on the traditional goal of understanding vis a vis the recently evolved view of landscape and anthropism.
Landscape statistics of the low autocorrelated binary string problem
Stadler, Peter F.
, NM 87501, USA Abstract. The statistical properties of the energy landscape of the low autocorrelated]. In this contribution we carry out a thorough investigation of the statistical properties of the energy landscapeLandscape statistics of the low autocorrelated binary string problem Fernando F. Ferreira a , Jos
Landscape statistics of the low autocorrelated binary string problem
Stadler, Peter F.
, NM 87501, USA Abstract. The statistical properties of the energy landscape of the low autocorrelated]. In this contribution we carry out a thorough investigation of the statistical properties of the energy landscapeLandscape statistics of the low autocorrelated binary string problem Fernando F. Ferreiraa , Jos
Effective string theory description of the interface free energy
M. Billo; M. Caselle; L. Ferro; M. Hasenbusch; M. Panero
2007-10-09T23:59:59.000Z
We compare the predictions of the Nambu-Goto effective string model with a set of high precision Monte Carlo results for interfaces with periodic boundary conditions in the 3D Ising model. We compute the free energy in the covariant gauge exactly, up to the inclusion of the Liouville mode. The perturbative expansion of this result agrees both with the result evaluated several years ago by Dietz and Filk in the physical gauge and with a recent calculation with the Polchinski-Strominger action. We also derive the effective string spectrum which, because of the different boundary conditions, is very different from the well known one of Arvis. Taking into proper account the effective string corrections and exploiting some technical improvements in the simulations we obtain precise estimate of the amplitude ratios T_c/\\sqrt{sigma}, m_{0++}/\\sqrt{\\sigma} and sigma xi_{2nd}^2. We also discuss the behaviour of the effective string free energy in the dimensional reduction limit (i.e., near the deconfinement transition of the dual 3d gauge Ising model) and its relationship with the 2d Ising model interfaces
Brane cosmic string compactification in Brans-Dicke theory
Abdalla, M. C. B.; Hoff da Silva, J. M. [Instituto de Fisica Teorica, Universidade Estadual Paulista, Rua Pamplona 145 01405-900 Sao Paulo, SP (Brazil); Guimaraes, M. E. X. [Departamento de Matematica, Universidade de Brasilia, Asa Norte 70910-900, Brasilia-DF (Brazil)
2007-04-15T23:59:59.000Z
We investigate an alternative compactification of extra dimensions using local cosmic string in the Brans-Dicke gravity framework. In the context of dynamical systems it is possible to show that there exist a stable field configuration for the Einstein-Brans-Dicke equations. We explore the analogies between this particular model and the Randall-Sundrum scenario.
Introduction to conformal field theory and string theory
Dixon, L.J.
1989-12-01T23:59:59.000Z
These lectures are meant to provide a brief introduction to conformal field theory (CFT) and string theory for those with no prior exposure to the subjects. There are many excellent reviews already available, and most of these go in to much more detail than I will be able to here. 52 refs., 11 figs.
String Phenomenology in the Era of LHC
Maxin, James A.
2010-10-12T23:59:59.000Z
we consistently apply throughout this work: 1. The 5-year WMAP data combined with measurements of Type Ia supernovae and baryon acoustic oscillations in the galaxy distribution for the cold dark matter density [4], 0.1109 ? ??oh2 ? 0.1177, where a...
Technology Successes in Hanford Tank Waste Storage and Retrieval
Cruz, E. J.
2002-02-26T23:59:59.000Z
The U. S. Department of Energy (DOE), Office of River Protection (ORP) is leading the River Protection Project (RPP), which is responsible for dispositioning approximately 204,000 cubic meters (54 million gallons) of high-level radioactive waste that has accumulated in 177 large underground tanks at the Hanford Site since 1944. The RPP is comprised of five major elements: storage of the waste, retrieval of the waste from the tanks, treatment of the waste, disposal of treated waste, and closure of the tank facilities. Approximately 3785 cubic meters (1 million gallons) of waste have leaked from the older ''single-shell tanks.'' Sixty-seven of the 147 single shell tanks are known or assumed ''leakers.'' These leaks have resulted in contaminant plumes that extend from the tank to the groundwater in a number of tank farms. Retrieval and closure of the leaking tanks complicates the ORP technical challenge because cleanup decisions must consider the impacts of past leaks along with a strategy for retrieving the waste in the tanks. Completing the RPP mission as currently planned and with currently available technologies will take several decades and tens of billions of dollars. RPP continue to pursue the benefits from deploying technologies that reduce risk to human health and the environment, as well as, the cost of cleanup. This paper discusses some of the recent technology partnering activities with the DOE Office of Science and Technology activities in tank waste retrieval and storage.
Dynamic Two-Stage Image Retrieval from Large Multimodal Databases
Arampatzis, Avi
on white background would retrieve a red pie-chart on white paper. If the query image happens to have a low generality, early rank positions may be dominated by spurious results such as the pie-chart, which may even
Test plan for air monitoring during the Cryogenic Retrieval Demonstration
Yokuda, E.
1992-06-01T23:59:59.000Z
This report presents a test plan for air monitoring during the Cryogenic Retrieval Demonstration (CRD). Air monitors will be used to sample for the tracer elements neodymium, terbium, and ytterbium, and dysprosium. The results from this air monitoring will be used to determine if the CRD is successful in controlling dust and minimizing contamination. Procedures and equipment specifications for the test are included.
A Model for Serendipitous Music Retrieval Markus Schedl, David Hauger
Widmer, Gerhard
A Model for Serendipitous Music Retrieval Markus Schedl, David Hauger Johannes Kepler University Department of Computational Perception {markus.schedl,david.hauger}@jku.at Dominik Schnitzer Austrian permission and/or a fee. CaRR 2012, February 14, 2012, Lisbon, Portugal. Copyright 2012 ACM 978
GLOBAL AEROSOL EFFECT RETRIEVAL FROM PASSIVE HYPERSPECTRAL MEASUREMENTS
Graaf, Martin de
that can be detected using UV reflectance measurements. Since the aerosol extinction optical thickness any instrument, or a combination of instruments, that measures UV, visible and SWIR reflectancesGLOBAL AEROSOL EFFECT RETRIEVAL FROM PASSIVE HYPERSPECTRAL MEASUREMENTS M. de Graaf1,2 , L. G
Information Granulation for Web based Information Retrieval Support Systems
Yao, JingTao
Department of Computer Science University of Regina Regina, Saskatchewan, Canada S4S 0A2 E-mail: {jtyao, yyao. These URLs provide location information. Like titles of books in traditional libraries, no one can remember and out dated information. Information retrieval systems provide useful information in libraries
CRAD, Occupational Safety & Health- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Occupational Safety and Industrial Hygiene Program at the Idaho Accelerated Retrieval Project Phase II.
Automatic Detection of Treatment Relationships for Patent Retrieval
Cárdenas, Alfonso F.
Automatic Detection of Treatment Relationships for Patent Retrieval Aaron Chu UCLA Computer Science Department Los Angeles, California 90024 aaronc@ucla.edu Shigeyuki Sakurai1 4 th Patent Examination Department Japan Patent Office Tokyo, Japan sakurai-shigeyuki@jpo.go.jp Alfonso F. Cardenas UCLA Computer
Deep Learning Representation using Autoencoder for 3D Shape Retrieval
benchmarks. I. INTRODUCTION With the fast development of 3D printer, Microsoft Kinect sensor and laserDeep Learning Representation using Autoencoder for 3D Shape Retrieval Zhuotun Zhu, Xinggang Wang@hust.edu.cn Abstract--We study the problem of how to build a deep learning representation for 3D shape. Deep learning
Matrix Factorizations for Information Retrieval Dianne P. O'Leary
O'Leary, Dianne P.
Matrix Factorizations for Information Retrieval Dianne P. O'Leary Computer Science Dept that is predominantly linear algebra · Conclusions A Catalog of Matrix Factorizations c 2006 Dianne P. O'Leary 1 or oscillation · understanding Markov chains c 2006 Dianne P. O'Leary 2 University of Maryland, College Park #12
CRAD, Conduct of Operations- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February, 2006 Commencement of Operations assessment of the Conduct of Operations program at the Idaho Accelerated Retrieval Project Phase II.
XML Multimedia Retrieval Zhigang Kong and Mounia Lalmas
Lalmas, Mounia
XML Multimedia Retrieval Zhigang Kong and Mounia Lalmas Department of Computer Science, Queen Mary, University of London {cskzg, mounia}@dcs.qmul.ac.uk Abstract. Multimedia XML documents can be viewed as a tree, whose nodes correspond to XML elements, and where multimedia objects are referenced in attributes
CRAD, Maintenance- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Maintenance program at the Idaho Accelerated Retrieval Project Phase II.
Automated Message Prioritization: Making Voicemail Retrieval More Efficient
Hirschberg, Julia
Automated Message Prioritization: Making Voicemail Retrieval More Efficient Meredith Ringel@research.att.com ABSTRACT Navigating through new voicemail messages to find messages of interest is a time-consuming task, particularly for high-volume users. When checking messages under a time constraint (e.g., during a brief
Resources Annotation, Retrieval and Presentation: a Semantic Annotation Management System
Paris-Sud XI, Université de
for the management of metadata records, each attribute of the record being represented by one or more triples to the resource management system itself. Expressing metadata records in RDF allows us to see metadata as semanticResources Annotation, Retrieval and Presentation: a Semantic Annotation Management System M. Albert
Pitch Histograms in Audio and Symbolic Music Information Retrieval
Tzanetakis, George
. A multiple-pitch detection algorithm for polyphonic signals is used to calculate Pitch Histograms for audioPitch Histograms in Audio and Symbolic Music Information Retrieval George Tzanetakis (corresponding Histograms are defined and proposed as a way to represent the pitch content of music signals both in symbolic
Correlation-Based Burstiness for Logo Retrieval Jerome Revaud
Paris-Sud XI, Université de
Correlation-Based Burstiness for Logo Retrieval Jerome Revaud INRIA Grenoble jerome.schmid@inria.fr ABSTRACT Detecting logos in photos is challenging. A reason is that logos locally resemble patterns the weight of correlated keypoint matches is reduced, penal- izing irrelevant logo detections. In experiments
Design package for fuel retrieval system fuel handling tool modification
TEDESCHI, D.J.
1998-11-09T23:59:59.000Z
This is a design package that contains the details for a modification to a tool used for moving fuel elements during loading of MCO Fuel Baskets for the Fuel Retrieval System. The tool is called the fuel handling tool (or stinger). This document contains requirements, development design information, tests, and test reports.
Design package for fuel retrieval system fuel handling tool modification
TEDESCHI, D.J.
1999-03-17T23:59:59.000Z
This is a design package that contains the details for a modification to a tool used for moving fuel elements during loading of MCO Fuel Baskets for the Fuel Retrieval System. The tool is called the fuel handling tool (or stinger). This document contains requirements, development design information, tests, and test reports.
Design Package for Fuel Retrieval System Fuel Handling Tool Modification
TEDESCHI, D.J.
2000-03-27T23:59:59.000Z
This is a design package that contains the details for a modification to a tool used for moving fuel elements during loading of MCO Fuel Baskets for the Fuel Retrieval System. The tool is called the fuel handling tool (or stinger). This document contains requirements, development design information, tests, and test reports.
Design package Lazy Susan for the fuel retrieval system
TEDESCHI, D.J.
1998-11-09T23:59:59.000Z
This is a design package that contains the details for a Lazy Susan style small tool for the Fuel Retrieval System. The Lazy Susan tool is used to help rotate an MCO Fuel Basket when loading it. This document contains requirements, development design information, tests and test reports that pertain to the production of Lazy Susan small tool.
Design package lazy susan for the fuel retrieval system
TEDESCHI, D.J.
1999-09-10T23:59:59.000Z
This is a design package that contains the details for a Lazy Susan style small tool for the Fuel Retrieval System. The Lazy Susan tool is used to help rotate an MCO Fuel Basket when loading it. This document contains requirements, development design information, tests and test reports that pertain to the production of Lazy Susan small tool.
Bloggers as Experts Feed Distillation using Expert Retrieval Models
de Rijke, Maarten
Bloggers as Experts Feed Distillation using Expert Retrieval Models Krisztian Balog kbalog Kruislaan 403, 1098 SJ Amsterdam ABSTRACT We address the task of (blog) feed distillation: to find blogs- ness as feed distillation strategies. The two models capture the idea that a human will often search
CRAD, Engineering- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Engineering program at the Idaho Accelerated Retrieval Project Phase II.
CRAD, Fire Protection- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Fire Protection program at the Idaho Accelerated Retrieval Project Phase II.
Physical retrieval of surface emissivity spectrum from hyperspectral infrared radiances
Li, Jun
Physical retrieval of surface emissivity spectrum from hyperspectral infrared radiances Jun Li,1 emissivity. Using constant or inaccurate surface emissivities typically results in large temperature and moisture profile errors, particularly over semi-arid or arid areas where the variation in emissivity
A Proposal for Chemical Information Retrieval Evaluation Jianhan Zhu
Zhu, Jianhan
A Proposal for Chemical Information Retrieval Evaluation Jianhan Zhu University College London Vienna, Austria john.tait@ir-facility.org ABSTRACT Based on the important progresses made in information evaluations on chemistry datasets in order to promote the research in chemical IR in general and chemical
CRAD, Emergency Management- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Emergency Management program at the Idaho Accelerated Retrieval Project Phase II.
CRAD, Quality Assurance- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Quality Assurance Program at the Idaho Accelerated Retrieval Project Phase II.
Failed Retrieval Attempts Foster Generation of Novel Responses
Angello, Genna Marie
2014-07-31T23:59:59.000Z
, participants may study category-exemplar word pairs such as fruit banana; fruit orange; fruit guava; fruit mango; tree birch; tree elm; tree juniper; tree ash. Then, participants are given the task to retrieve half of the exemplars, such as orange and mango...
Inferring Geographical Ontologies from Multiple Resources for Geographical Information Retrieval
Rosso, Paolo
) and the Geographic Names Information System5 (GNIS) are freely available and pro- vide plenty of geographicalInferring Geographical Ontologies from Multiple Resources for Geographical Information Retrieval task. In many cases, explicit geographical information is missing from the documents, for instance
Active and Knowledge-based Process Safety Incident Retrieval System
Khan, Sara Shammni
2011-10-21T23:59:59.000Z
. Importance plot for the word ?overpressure? .................................................. 31 Figure 14. Importance plot for the binary categorical variable ?Release? ....................... 32 Figure 15. Importance plot for the word ?release... database with its unique guided search system and modern information retrieval techniques and linking it with operational software would provide a powerful tool and would improve safety and hence reduce costs. 4 2. BACKGROUND 2...
Modern Information Retrieval: A Brief Overview Amit Singhal
Gravano, Luis
for efficient use of information. They developed special classifications to identify every tablet and its content. (See http://www.libraries.gr for a wonderful historical perspective on modern libraries.) The need to store and retrieve written information became increasingly important over centuries, especially
Efficiency Considerations for Scalable Information Retrieval Ophir Frieder
Efficiency Considerations for Scalable Information Retrieval Servers Ophir Frieder Department Washington, DC 20052 frieder@seas.gwu.edu Abstract We review a variety of techniques to improve efficiency and using such techniques is critical. We address several efficiency concerns, but our primary focus
Scalable K-Means by Ranked Retrieval Andrei Broder
Cortes, Corinna
Scalable K-Means by Ranked Retrieval Andrei Broder Google 1600 Amphitheater Parkway Mountain View, CA 94043 broder @google.com Lluis Garcia-Pueyo Google 1600 Amphitheater Parkway Mountain View, CA 94043 lgpueyo@google.com Vanja Josifovski Google 1600 Amphitheater Parkway Mountain View, CA 94043
Retrieval Name: Information Release -54 Issue Date: April 20, 2006
Retrieval Name: Information Release - 54 Issue Date: April 20, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #54 Page 1 PeopleSoft IR- #54 LSUSH - Month of March 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH
The Seventeen Theoretical Constructs of Information Searching and Information Retrieval
Jansen, James
The Seventeen Theoretical Constructs of Information Searching and Information Retrieval Bernard J. Jansen College of Information Sciences and Technology, The Pennsylvania State University, University Park, PA 16801. E-mail: jjansen@acm.org Soo Young Rieh School of Information, University of Michigan, Ann
Retrieval Name: Information Release -57 Issue Date: June 19, 2006
Retrieval Name: Information Release - 57 Issue Date: June 19, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #57 Page 1 PeopleSoft IR- #57 LSUSH - Month of May 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH Financial
Retrieval Name: Information Release -58 Issue Date: August 29, 2006
Retrieval Name: Information Release - 58 Issue Date: August 29, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #58 Page 1 PeopleSoft IR- #58 LSUSH & EACMC - Month of June 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies
Retrieval Name: Information Release -53 Issue Date: March 20, 2006
Retrieval Name: Information Release - 53 Issue Date: March 20, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #50 Page 1 PeopleSoft IR- #53 LSUSH - Month of February 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH
Retrieval Name: Information Release -52 Issue Date: February 16, 2006
Retrieval Name: Information Release - 52 Issue Date: February 16, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #52 Page 1 PeopleSoft IR- #52 LSUSH - MonthSoft Information Release (IR) applies to the LSUSH Financial Community responsible for management
Draft for comment Important problems in information retrieval
Soergel, Dagobert
Draft for comment Important problems in information retrieval Dagobert Soergel College of Library and Information Services University of Maryland College Park, MD 20742 August 1989 (Most of the work on this paper the problem and determining information needs. Problem 2. Knowing how people use and process information
Retrieval Name: Information Release 59 Issue Date: September 20, 2006
Retrieval Name: Information Release 59 Issue Date: September 20, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #59 Page 1 PeopleSoft IR- #59 LSUSH - Month of July 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH
Retrieval Name: Information Release -55 Issue Date: May 16, 2006
Retrieval Name: Information Release - 55 Issue Date: May 16, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #55 Page 1 PeopleSoft IR- #55 LSUSH and EACMC - Month of April 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH
Retrieval Name: Information Release 61 Issue Date: October 17, 2006
Retrieval Name: Information Release 61 Issue Date: October 17, 2006 Revision Date: Originator: LSUSH Accounting Services Rescind Date: Information Release #61 Page 1 PeopleSoft IR- #61 LSUSH - Month of September 2006 General Ledger Closed Scope: This PeopleSoft Information Release (IR) applies to the LSUSH
CRAD, Management- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Management at the Idaho Accelerated Retrieval Project Phase II.
CRAD, Training- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Training Program at the Idaho Accelerated Retrieval Project Phase II.
CRAD, Radiological Controls- Idaho Accelerated Retrieval Project Phase II
Broader source: Energy.gov [DOE]
A section of Appendix C to DOE G 226.1-2 "Federal Line Management Oversight of Department of Energy Nuclear Facilities." Consists of Criteria Review and Approach Documents (CRADs) used for a February 2006 Commencement of Operations assessment of the Radiation Protection Program at the Idaho Accelerated Retrieval Project Phase II.
Kazuyuki Furuuchi
2008-06-30T23:59:59.000Z
Closed string field theory is constructed by stochastically quantizing a matrix model for Polyakov loops that describes phases of a large N gauge theory at finite temperature. Coherent states in this string field theory describes winding string condensation which has been expected to cause a topology change from thermal AdS geometry to AdS-Schwarzschild black hole geometry. D-branes in this closed string field theory is also discussed. Slightly extended version of a talk given at CosPA 2007, Nov.13-15, Taipei, Taiwan.
RIECK, C.A.
1999-02-23T23:59:59.000Z
This Software Configuration Management Plan (SCMP) provides the instructions for change control of the W-211 Project, Retrieval Control System (RCS) software after initial approval/release but prior to the transfer of custody to the waste tank operations contractor. This plan applies to the W-211 system software developed by the project, consisting of the computer human-machine interface (HMI) and programmable logic controller (PLC) software source and executable code, for production use by the waste tank operations contractor. The plan encompasses that portion of the W-211 RCS software represented on project-specific AUTOCAD drawings that are released as part of the C1 definitive design package (these drawings are identified on the drawing list associated with each C-1 package), and the associated software code. Implementation of the plan is required for formal acceptance testing and production release. The software configuration management plan does not apply to reports and data generated by the software except where specifically identified. Control of information produced by the software once it has been transferred for operation is the responsibility of the receiving organization.
Hill Climbing Algorithms for Content-Based Retrieval of Similar Configurations
Papadias, Dimitris
Hill Climbing Algorithms for Content-Based Retrieval of Similar Configurations Dimitris Papadias Department of Computer Science Hong Kong University of Science and Technology Clear Water Bay, Hong Kong +852 is an important form of content-based retrieval. Exhaustive processing (i.e., retrieval of the best solutions
Integrating XLink and XPath to Retrieve Structured Multimedia Documents in Digital Libraries
Lalmas, Mounia
Integrating XLink and XPath to Retrieve Structured Multimedia Documents in Digital Libraries data according to user information needs, multimedia information retrieval in digital libraries must the retrieval of multimedia data in digital libraries based on XML format. For this purpose, we integrate XLink
Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS
Oxford, University of
Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS E. Papandrea,1,2 A2O2. We demonstrate the feasibility of profile retrievals in the range 635 km and obtain zonal mean), Retrieval of global hydrogen peroxide (H2O2) profiles using ENVISAT-MIPAS, Geophys. Res. Lett., 32, L14809
fMRI Brain Image Retrieval Based on ICA Components bbai@cs.rutgers.edu
fMRI Brain Image Retrieval Based on ICA Components Bing Bai bbai@cs.rutgers.edu Department This manuscript proposes a retrieval system for fMRI brain images. Our goal is to find a similarity- metric to enable us to support queries for "similar tasks" for retrieval on a large collection of brain ex
DOVALLE, O.R.
1999-12-29T23:59:59.000Z
This document is one of the several documents prepared by Lockheed Martin Hanford Corp. to support the U. S. Department of Energy's Tank Waste Retrieval and Disposal mission at Hanford. The Tank Waste Retrieval and Disposal mission includes the programs necessary to support tank waste retrieval; waste feed, delivery, storage, and disposal of immobilized waste; and closure of the tank farms.
Retrievals of Carbon Dioxide from GOSAT: Validation, model comparison and approach development
Retrievals of Carbon Dioxide from GOSAT: Validation, model comparison and approach development properties of aerosol and cirrus particles. 3. Model Comparison Retrievals of XCO2 were performed on cloud and compared to the CarbonTracker model. The retrieval averaging kernels were applied to Carbon
University of Twente at GeoCLEF 2006: geofiltered document retrieval
Theune, Mariët
in building a Geographic Information Retrieval system and a large effort went into constructing a geographic a gazetteer. The results do not show an improvement in retrieval performance when taking geographical information into account. Categories and Subject Descriptors H.3 [Information Storage and Retrieval]: H.3
Retrieving the effective radius of Saharan dust coarse mode from AIRS Clemence Pierangelo,1
of the temperature and water vapor profiles are obtained from 8 spectral channels, using a Look-Up-Table approach, transport model simulations and sun-photometer retrievals. We find that the coarse mode effective radius to retrieve information on dust size distribution. For instance, bimodal size distributions can be retrieved
state in the retrieval algorithms Jun Wang1 and Scot T. Martin1 Received 27 September 2006; revised 5-of-the-art retrieval algorithms widely omit variable hygroscopicity and mixing state. For the study described herein% and 0.2 mm, respectively, depending upon the retrieval algorithm's assumptions regarding hygroscopicity
Term-Specific Smoothing for the Language Modeling Approach to Information Retrieval
Hiemstra, Djoerd
and Retrieval General Terms Theory Keywords Information Retrieval, Formal Models, Language Models, Search simple web search engine examples.2 If we for instance enter the query IT magazines in GoogleTerm-Specific Smoothing for the Language Modeling Approach to Information Retrieval: The Importance
Accelerated universes from type IIA compactifications
Blĺbäck, Johan; Danielsson, Ulf; Dibitetto, Giuseppe, E-mail: johan.blaback@physics.uu.se, E-mail: ulf.danielsson@physics.uu.se, E-mail: giuseppe.dibitetto@physics.uu.se [Institutionen för fysik och astronomi, Uppsala Universitet, Box 803, Uppsala SE-751 08 (Sweden)
2014-03-01T23:59:59.000Z
We study slow-roll accelerating cosmologies arising from geometric compactifications of type IIA string theory on T{sup 6}/(Z{sub 2} × Z{sub 2}). With the aid of a genetic algorithm, we are able to find quasi-de Sitter backgrounds with both slow-roll parameters of order 0.1. Furthermore, we study their evolution by numerically solving the corresponding time-dependent equations of motion, and we show that they actually display a few e-folds of accelerated expansion. Finally, we comment on their perturbative reliability.
An ARSCL-based cloud type climatology from retrievals and it's use in
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article)41cloth Documentation DataDepartment of EnergyOn-Farm Biofuelin HawaiiNatural GasofAmesoptical probe for localmodel
On supersymmetric interfaces for string theory
Yuji Satoh
2012-03-09T23:59:59.000Z
We construct the world-sheet interface which preserves space-time supersymmetry in type II superstring theories in the Green-Schwarz formalism. This is an analog of the conformal interface in two-dimensional conformal field theory. We show that a class of the supersymmetric interfaces generates T-dualities of type II theories, and that these interfaces have a geometrical interpretation in the doubled target space. We compute the partition function with a pair of the supersymmetric interfaces inserted, from which we read off the spectrum of the modes coupled to the interfaces and the Casimir energy between them. We also derive the transformation rules under which a set of D-branes is transformed to another by the interface.
Geryville, Hichem; Bouras, Abdelaziz; Sapidis, Nikolaos
2007-01-01T23:59:59.000Z
Nowadays, to achieve competitive advantage, the industrial companies are considering that success is sustained to great product development. That is to manage the product throughout its entire lifecycle. Achieving this goal requires a tight collaboration between actors from a wide variety of domains, using different software tools producing various product data types and formats. The actors' collaboration is mainly based on the exchange /share product information. The representation of the actors' viewpoints is the underlying requirement of the collaborative product development. The multiple viewpoints approach was designed to provide an organizational framework following the actors' perspectives in the collaboration, and their relationships. The approach acknowledges the inevitability of multiple integration of product information as different views, promotes gathering of actors' interest, and encourages retrieved adequate information while providing support for integration through PLM and/or SCM collaborati...
Vejvoda, E.J.; Pottmeyer, J.A.; DeLorenzo, D.S.; Weyns-Rollosson, M.I. [Los Alamos Technical Associates, Inc., NM (United States); Duncan, D.R. [Westinghouse Hanford Co., Richland, WA (United States)
1993-10-01T23:59:59.000Z
During the next two decades the transuranic (TRU) wastes now stored in the burial trenches and storage facilities at the Hanford Site are to be retrieved, processed at the Waste Receiving and Processing Facility, and shipped to the Waste Isolation Pilot Plant near Carlsbad, New Mexico for final disposal. Approximately 3.8% of the TRU waste to be retrieved for shipment to WIPP was generated at the General Electric (GE) Vallecitos Nuclear Center (VNC) in Pleasanton, California and shipped to the Hanford Site for storage. The purpose of this report is to characterize these radioactive solid wastes using process knowledge, existing records, and oral history interviews. The waste was generated almost exclusively from the activities, of the Plutonium Fuels Development Laboratory and the Plutonium Analytical Laboratory. Section 2.0 provides further details of the VNC physical plant, facility operations, facility history, and current status. The solid radioactive wastes were associated with two US Atomic Energy Commission/US Department of Energy reactor programs -- the Fast Ceramic Reactor (FCR) program, and the Fast Flux Test Reactor (FFTR) program. These programs involved the fabrication and testing of fuel assemblies that utilized plutonium in an oxide form. The types and estimated quantities of waste resulting from these programs are discussed in detail in Section 3.0. A detailed discussion of the packaging and handling procedures used for the VNC radioactive wastes shipped to the Hanford Site is provided in Section 4.0. Section 5.0 provides an in-depth look at this waste including the following: weight and volume of the waste, container types and numbers, physical description of the waste, radiological components, hazardous constituents, and current storage/disposal locations.
Hanford tank initiative vehicle/based waste retrieval demonstration report phase II, track 2
Berglin, E.J.
1997-07-31T23:59:59.000Z
Using the versatile TracPUMpTm, Environmental Specialties Group, LLC (ES) performed a successful Phase 11 demonstration of a Vehicle- Based Waste Retrieval System (VWRS) for removal of waste material and residual liquid found in the Hanford Underground Storage Tanks (ousts). The purpose of this demonstration was to address issues pertaining to the use of a VWRS in OUSTS. The demonstration also revealed the waste removal capabilities of the TracPumpTm and the most effective techniques and equipment to safely and effectively remove waste simulants. ES successfully addressed the following primary issues: I . Dislodge and convey the waste forms present in the Hanford OUSTS; 2. Access the UST through tank openings as small as twenty-four inches in diameter; 3. Traverse a variety of terrains including slopes, sludges, rocks and hard, slippery surfaces without becoming mired; 4. Dislodge and convey waste within the confinement of the Decontamination Containment Capture Vessel (DCCV) and with minimal personnel exposure; 5. Decontaminate equipment to acceptable limits during retrieval from the UST; 6. Perform any required maintenance within the confinement of the DCCV; and 7. Maintain contaminate levels ``as low as reasonably achievable`` (ALARA) within the DCCV due to its crevice and comer-free design. The following materials were used to simulate the physical characteristics of wastes found in Hanford`s OUSTS: (1) Hardpan: a clay-type material that has high shear strength; (2) Saltcake: a fertilizer-based material that has high compressive strength; and (3) Wet Sludge.- a sticky, peanut- butter- like material with low shear strength. Four test beds were constructed of plywood and filled with a different simulant to a depth of eight to ten inches. Three of the test beds were of homogenous simulant material, while the fourth bed consisted of a mixture of all three simulant types.
Design package test weights for fuel retrieval system (OCRWM)
TEDESCHI, D.J.
1999-10-26T23:59:59.000Z
This is a design package that documents the development of test weights used in the Spent Nuclear Fuels subproject Fuel Retrieval System. The K Basins Spent Nuclear Fuel (SNF) project consists of the safe retrieval, preparation, and repackaging of the spent fuel stored at the K East (KE) and K West (KW) Basins for interim safe storage in the Canister Storage Building (CSB). Multi-Canister Overpack (MCO) scrap baskets and fuel baskets will be loaded and weighed under water. The equipment used to weigh the loaded fuel baskets requires daily calibration checks, using test weights traceable to National Institute of Standards Testing (NIST) standards. The test weights have been designated as OCRWM related in accordance with HNF-SD-SNF-RF'T-007 (McCormack).
Gauge field, strings, solitons, anomalies and the speed of life
Niemi, Antti J
2014-01-01T23:59:59.000Z
It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that perta...
Generalized Duality and Singular Strings in Higher Dimensions
I. Bars; K. Sfetsos
1991-10-24T23:59:59.000Z
Deformations of gauged WZW actions are constructed for any pair $(G,H)$ by taking different embeddings of the gauge group $H\\subset G$ as it acts on the left and right of the group element $g$. This leads to models that are dual to each other, generalizing the axial/vector duality of the two dimensional black hole manifold. The classical equations are completely solved for any pair $(G,H)$ and in particular for the anti de Sitter string based on $SO(d- 1,2)/SO(d-1,1)$ for which the normal modes are determined. Duality is demonstrated for models that have the same set of normal modes. Concentrating on $SO(2,2)/SO(2,1)$, the metric and dilaton fields of the $d=3$ string as well as some of the dual generalizations are obtained. They have curvature singularities and represent new singular solutions of Einstein's general relativity in three dimensions.
Gamma-ray bursts, axion emission and string theory dilaton
O. Bertolami
1999-01-14T23:59:59.000Z
The emission of axions from supernovae is an interesting possibility to account for the Gamma-Ray Bursts provided their energy can be effectively converted into electromagnetic energy elsewhere. The connection between supernova and gamma-ray bursts has been recently confirmed by the observed correlation between the burst of April 25, 1998 and the supernova SN1998bw. We argue that the axion convertion into photons can be more efficient if one considers the coupling between an intermediate scale axion and the string theory dilaton along with the inclusion of string loops. We also discuss the way dilaton dynamics may allow for a more effective energy exchange with electromagnetic radiation in the expansion process of fireballs.
Hacker, Randi; Tsutsui, William
2007-03-14T23:59:59.000Z
Sox spent a hundred mil to acquire pitcher Daisuke Matsuzaka; they probably weren't even aware that he is a Type O and that they make the best bankers, politicians and... you guessed it... professional baseball players. #ceas #hacker #japan #tsutsuien...
Probabilistic retrieval and visualization of biologically relevant microarray experiments
2009-10-19T23:59:59.000Z
International Society for Computational Biology (ISCB) Student Council Symposium Stockholm, Sweden 27 June 2009 Published: 19 October 2009 BMC Bioinformatics 2009, 10(Suppl 13):P1 doi: 10.1186/1471-2105-10-S13-P1 This article is available from: http... BMC Bioinformatics Poster presentation Probabilistic retrieval and visualization of biologically relevant microarray experiments José Caldas*1, Nils Gehlenborg2,3, Ali Faisal1, Alvis Brazma2 and Samuel Kaski1 Address: 1Helsinki Institute...
Optimal Storage and Retrieval of Single-Photon Waveforms
Shuyu Zhou; Shanchao Zhang; Chang Liu; J. F. Chen; Jianming Wen; M. M. T. Loy; G. K. L. Wong; Shengwang Du
2012-07-11T23:59:59.000Z
We report an experimental demonstration of optimal storage and retrieval of heralded single-photon wave packets using electromagnetically induced transparency (EIT) in cold atoms at a high optical depth. We obtain an optimal storage efficiency of (49+/-3)% for single-photon waveforms with a temporal likeness of 96%. Our result brings the EIT quantum light-matter interface close to practical quantum information applications.
Hanford`s spent nuclear fuel retrieval: an agressive agenda
Shen, E.J., Westinghouse Hanford
1996-12-06T23:59:59.000Z
Starting December 1997, spent nuclear fuel that has been stored in the K Reactor Fuel Storage Basins will be retrieved over a two year period and repackaged for long term dry storage. The aging and sometimes corroding fuel elements will be recovered and processed using log handled tools and teleoperated manipulator technology. The U.S. Department of Energy (DOE) is committed to this urgent schedule because of the environmental threats to the groundwater and nearby the Columbia River.
ARM - PI Product - Aerosol Retrievals from ARM SGP MFRSR Data
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports(Journal Article) |govInstrumentsmfrirt Documentation ARMupwelling irradiance ARM Data DiscoveryMethaneProductsAerosol Retrievals from ARM SGP
System to control contamination during retrieval of buried TRU waste
Menkhaus, D.E.; Loomis, G.G.; Mullen, C.K.; Scott, D.W.; Feldman, E.M.; Meyer, L.C.
1993-04-20T23:59:59.000Z
A system is described to control contamination during the retrieval of hazardous waste comprising an outer containment building, an inner containment building, within the outer containment building, an electrostatic radioactive particle recovery unit connected to and in communication with the inner and outer containment buildings, and a contaminate suppression system including a moisture control subsystem, and a rapid monitoring system having the ability to monitor conditions in the inner and outer containment buildings.
System to control contamination during retrieval of buried TRU waste
Menkhaus, Daniel E. (Idaho Falls, ID); Loomis, Guy G. (Idaho Falls, ID); Mullen, Carlan K. (Idaho Falls, ID); Scott, Donald W. (Idaho Falls, ID); Feldman, Edgar M. (Idaho Falls, ID); Meyer, Leroy C. (Idaho Falls, ID)
1993-01-01T23:59:59.000Z
A system to control contamination during the retrieval of hazardous waste comprising an outer containment building, an inner containment building, within the outer containment building, an electrostatic radioactive particle recovery unit connected to and in communication with the inner and outer containment buildings, and a contaminate suppression system including a moisture control subsystem, and a rapid monitoring system having the ability to monitor conditions in the inner and outer containment buildings.
Stability of false vacuum in supersymmetric theories with cosmic strings
Kumar, Brijesh; Yajnik, Urjit A. [Department of Physics, Indian Institute of Technology, Bombay, Mumbai - 400076 (India)
2009-03-15T23:59:59.000Z
We study the stability of supersymmetry breaking vacuum in the presence of cosmic strings arising in the messenger sector. For certain ranges of the couplings, the desired supersymmetry breaking vacua become unstable against decay into phenomenologically unacceptable vacua. This sets constraints on the range of allowed values of the coupling constants appearing in the models and more generally on the chosen dynamics of gauge symmetry breaking.
Boundary String Field Theory of the DDbar System
Kraus, P; Kraus, Per; Larsen, Finn
2001-01-01T23:59:59.000Z
We develop the boundary string field theory approach to tachyon condensation on the DDbar system. Particular attention is paid to the gauge fields, which combine with the tachyons in a natural way. We derive the RR-couplings of the system and express the result in terms of Quillen's superconnection. The result is related to an index theorem, and is thus shown to be exact.
Effective Supergravity from the Weakly Coupled HeteroticString
Gaillard, Mary K.
2005-05-01T23:59:59.000Z
The motivation for Calabi-Yau-like compactifications of the weakly coupled E{sub 8} {circle_times} E{sub 8} heterotic string theory, its particle spectrum and the issue of dilaton stabilization are briefly reviewed. Modular invariant models for hidden sector condensation and supersymmetry breaking are described at the quantum level of the effective field theory. Their phenomenological and cosmological implications, including a possible origin for R-parity, are discussed.
Vacuum Polarization on the Schwarzschild Metric with a Cosmic String
Adrian C. Ottewill; Peter Taylor
2010-06-30T23:59:59.000Z
We consider the problem of the renormalization of the vacuum polarization in a symmetry space-time with axial but not spherical symmetry, Schwarzschild space-time threaded by an infinite straight cosmic string. Unlike previous calculations, our framework to compute the renormalized vacuum polarization does not rely on special properties of Legendre functions, but rather has been developed in a way that we expect to be applicable to Kerr space-time.
Hamilton-Jacobi formalism for string gas thermodynamics
Anosh Joseph; S. G. Rajeev
2009-03-27T23:59:59.000Z
We show that the thermodynamics of a system of strings at high energy densities under the ideal gas approximation has a formulation in terms of Hamilton-Jacobi theory. The two parameters of the system, which have dimensions of energy density and number density, respectively, define a family of hypersurfaces of co-dimension one, which can be described by the vanishing of a function F that plays the role of a Hamiltonian.
Thermal duality and gravitational collapse in heterotic string theories
Michael Hewitt
2015-07-04T23:59:59.000Z
The thermal duality of E(8) x E(8) and SO(32) heterotic string theories may underpin a mechanism that would convert the kinetic energy of infalling matter during gravitational collapse to form a region of a hot string phase that would expel gravitational gradients. This phase would be the continuation of a Ginzburg-Landau like superconductor in the Euclidean regime. In this scenario, there would be no event horizon or singularity produced in gravitational collapse. Solutions are presented for excitations of the string vacuum that may form during gravitational collapse and drive the transition to the hot phase. The proposed mechanism is developed here for the case of approximately spherical gravitational collapse in 4 uncompactified spacetime dimensions. A way to reconcile the large entropy apparently produced in this process with quantum mechanics is briefly discussed. In this scenario, astrophysical objects such as stellar or galactic cores which have undergone extreme gravitational collapse would currently be sites of an on-going conversion process to shells of this high temperature phase. The relationship of this proposal to the `firewall paradox' is noted.
Gauge field, strings, solitons, anomalies and the speed of life
Antti J. Niemi
2014-07-05T23:59:59.000Z
It's been said that "mathematics is biology's next microscope, only better; biology is mathematics' next physics, only better". Here we aim for something even better. We try to combine mathematical physics and biology into a picoscope of life. For this we merge techniques which have been introduced and developed in modern mathematical physics, largely by Ludvig Faddeev to describe objects such as solitons and Higgs and to explain phenomena such as anomalies in gauge fields. We propose a synthesis that can help to resolve the protein folding problem, one of the most important conundrums in all of science. We apply the concept of gauge invariance to scrutinize the extrinsic geometry of strings in three dimensional space. We evoke general principles of symmetry in combination with Wilsonian universality and derive an essentially unique Landau-Ginzburg energy that describes the dynamics of a generic string-like configuration in the far infrared. We observe that the energy supports topological solitons, that pertain to an anomaly in the manner how a string is framed around its inflection points. We explain how the solitons operate as modular building blocks from which folded proteins are composed. We describe crystallographic protein structures by multi-solitons with experimental precision, and investigate the non-equilibrium dynamics of proteins under varying temperature. We simulate the folding process of a protein at in vivo speed and with close to pico-scale accuracy using a standard laptop computer: With pico-biology as mathematical physics' next pursuit, things can only get better.
Interpolating the Coulomb Phase of Little String Theory
Ying-Hsuan Lin; Shu-Heng Shao; Yifan Wang; Xi Yin
2015-02-05T23:59:59.000Z
We study up to 8-derivative terms in the Coulomb branch effective action of (1,1) little string theory, by collecting results of 4-gluon scattering amplitudes from both perturbative 6D super-Yang-Mills theory up to 4-loop order, and tree-level double scaled little string theory (DSLST). In previous work we have matched the 6-derivative term from the 6D gauge theory to DSLST, indicating that this term is protected on the entire Coulomb branch. The 8-derivative term, on the other hand, is unprotected. In this paper we compute the 8-derivative term by interpolating from the two limits, near the origin and near the infinity on the Coulomb branch, numerically from SU(k) SYM and DSLST respectively, for k=2,3,4,5. We discuss the implication of this result on the UV completion of 6D SYM as well as the strong coupling completion of DSLST. We also comment on analogous interpolating functions in the Coulomb phase of circle-compactified (2,0) little string theory.
Experiences with string matching on the Fermi Architecture
Tumeo, Antonino; Secchi, Simone; Villa, Oreste
2011-02-25T23:59:59.000Z
String matching is at the core of many real-world applications, such as security, bioinformatic, data mining. All these applications requires the ability to match always growing data sets against large dictionaries effectively, fastly and possibly in real time. Unfortunately, string matching is a computationally intensive procedure which poses significant challenges on current software and hardware implementations. Graphic Processing Units (GPU) have become an interesting target for such high-throughput applications, but the algorithms and the data structures need to be redesigned to be parallelized and adapted to the underlining hardware, coping with the limitations imposed by these architectures. In this paper we present an efficient implementation of the Aho-Corasick string matching algorithm on GPU, showing how we progressively redesigned the algorithm and the data structures to fit on the architecture. We then evaluate the implementation on single and multiple Tesla C2050 (T20 ``Fermi'' based) boards, comparing them to the previous Tesla C1060 (T10 based) solutions and equivalent multicore implementations on x86 CPUs. We discuss the various tradeoffs of the different architectures.
Field Definitions, Spectrum and Universality in Effective String Theories
N. D. Hari Dass; Peter Matlock
2006-12-28T23:59:59.000Z
It is shown, by explicit calculation, that the third-order terms in inverse string length in the spectrum of the effective string theories of Polchinski and Strominger are also the same as in Nambu-Goto theory, in addition to the universal Luescher terms. While the Nambu-Goto theory is inconsistent outside the critical dimension, the Polchinski-Strominger theory is by construction consistent for any space-time dimension. In the analysis of the spectrum, care is taken not to use any field redefinition, as it is felt that this has the potential to obscure important points. Nevertheless, as field redefinition is an important tool and the definition of the field should be made precise, a careful analysis of the choice of field definition leading to the terms in the action is also presented. Further, it is shown how a choice of field definition can be made in a systematic way at higher orders. To this end the transformation of measure involved is calculated, in the context of effective string theory, and thereby a quantum evaluation made of equivalence of theories related by a field redefinition. It is found that there are interesting possibilities resulting from a redefinition of fluctuation field.
Dangerous Angular KK/Glueball Relics in String Theory Cosmology
J. F. Dufaux; L. Kofman; M. Peloso
2008-07-07T23:59:59.000Z
The presence of Kaluza-Klein particles in the universe is a potential manifestation of string theory cosmology. In general, they can be present in the high temperature bath of the early universe. In particular examples, string theory inflation often ends with brane-antibrane annihilation followed by the energy cascading through massive closed string loops to KK modes which then decay into lighter standard model particles. However, massive KK modes in the early universe may become dangerous cosmological relics if the inner manifold contains warped throat(s) with approximate isometries. In the complimentary picture, in the AdS/CFT dual gauge theory with extra symmetries, massive glueballs of various spins become the dangerous cosmological relics. The decay of these angular KK modes/glueballs, located around the tip of the throat, is caused by isometry breaking which results from gluing the throat to the compact CY manifold. We address the problem of these angular KK particles/glueballs, studying their interactions and decay channels, from the theory side, and the resulting cosmological constraints on the warped compactification parameters, from the phenomenology side. The abundance and decay time of the long-lived non-relativistic angular KK modes depend strongly on the parameters of the warped geometry, so that observational constraints rule out a significant fraction of the parameter space. In particular, the coupling of the angular KK particles can be weaker than gravitational.
Anomaly of Tensionless String in Light-cone Gauge
Murase, Kenta
2015-01-01T23:59:59.000Z
The classical tensionless string theory has the spacetime conformal symmetry. We expect and require that the quantum tensionless string theory has it too. In the BRST quantization method, the theory has no spacetime conformal anomaly in two dimensions. On the other hand, in the light-cone gauge quantization without the mode expansion, the theory in $D>3$ has the spacetime conformal anomaly in the traceless part of $[\\mathcal{J}^{-I}, \\mathcal{K}^{J}]$ in some operator order. In this paper, we consider a tensionless closed bosonic string in the light-cone gauge and investigate the spacetime conformal anomaly in the theory with the mode expansion. The appearance of the spacetime conformal anomaly in the light-cone gauge is different between the case of $D>3$ and the case of $D=3$ and depends on the choice of the operator order. Therefore we must consider dangerous commutators in the spacetime conformal symmetry of $D>3$ and $D=3$ in each operator order separately. Specifically we calculate dangerous commutators...
CERN Winter School on Supergravity, Strings, and Gauge Theory 2010
None
2011-10-06T23:59:59.000Z
The CERN Winter School on Supergravity, Strings, and Gauge Theory is the analytic continuation of the yearly training school of the former EC-RTN string network "Constituents, Fundamental Forces and Symmetries of the Universe". The 2010 edition of the school is supported and organized by the CERN Theory Divison, and will take place from Monday January 25 to Friday January 29, at CERN. As its predecessors, this school is meant primarily for training of doctoral students and young postdoctoral researchers in recent developments in theoretical high-energy physics and string theory. The programme of the school will consist of five series of pedagogical lectures, complemented by tutorial discussion sessions in the afternoons. Previous schools in this series were organized in 2005 at SISSA in Trieste, and in 2006, 2007, 2008, and 2009 at CERN, Geneva. Other similar schools have been organized in the past by the former related RTN network "The Quantum Structure of Spacetime and the Geometric Nature of Fundamental Interactions". This edition of the school is not funded by the European Union. The school is funded by the CERN Theory Division, and the Arnold Sommerfeld Center at Ludwig-Maximilians University of Munich. Scientific committee: M. Gaberdiel, D. Luest, A. Sevrin, J. Simon, K. Stelle, S. Theisen, A. Uranga, A. Van Proeyen, E. Verlinde Local organizers: A. Uranga, J. Walcher
Spiky strings and giant magnons on S5
M. Kruczenski; J. Russo; A. A. Tseytlin
2006-07-14T23:59:59.000Z
Recently, classical solutions for strings moving in AdS5 x S5 have played an important role in understanding the AdS/CFT correspondence. A large set of them were shown to follow from an ansatz that reduces the solution of the string equations of motion to the study of a well-known integrable 1-d system known as the Neumann-Rosochatius (NR) system. However, other simple solutions such as spiky strings or giant magnons in S5 were not included in the NR ansatz. We show that, when considered in the conformal gauge, these solutions can be also accomodated by a version of the NR-system. This allows us to describe in detail a giant magnon solution with two additional angular momenta and show that it can be interpreted as a superposition of two magnons moving with the same speed. In addition, we consider the spin chain side and describe the corresponding state as that of two bound states in the infinite SU(3) spin chain. We construct the Bethe ansatz wave function for such bound state.
Cveti?, Mirjam; Halverson, James
2010-01-01T23:59:59.000Z
We discuss a number of issues arising when computing non-perturbative effects systematically across the string theory landscape. In particular, we cast the study of fairly generic physical properties into the language of computability/number theory and show that this amounts to solving systems of diophantine equations. In analogy to the negative solution to Hilbert's 10th problem, we argue that in such systematic studies there may be no algorithm by which one can determine all physical effects. We take large volume type IIB compactifications as an example, with the physical property of interest being the low-energy non-perturbative F-terms of a generic compactification. A similar analysis is expected to hold for other kinds of string vacua, and we discuss in particular the extension of our ideas to F-theory. While these results imply that it may not be possible to answer systematically certain physical questions about generic type IIB compactifications, we identify particular Calabi-Yau manifolds in which the...
Conformal Transformations and Strings for an Accelerating Quark-Antiquark Pair in AdS3
Shijong Ryang
2014-12-08T23:59:59.000Z
From a simple moving open string solution dual to a moving heavy quark with constant velocity in the Poincare AdS_3 spacetime, we construct an accerlerating open string solution dual to a heavy quark-antiquark pair accelerated in opposite directions by performing the three mappings such as the SL(2,R)_L x SL(2,R)_R isometry transformation, the special conformal transformation and the conformal SO(2,2) transformation. Using the string sigma model action we construct two open string solutions staying in two different regions whose dividing line is associated with the event horizon appeared on the string worldsheet and obtain the accelerating open string solution by gluing two such solutions.
Constraints on cosmic (super)strings from the LIGO-Virgo gravitational-wave detectors
Aasi, J; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Adams, C; Adams, T; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ajith, P; Allen, B; Allocca, A; Ceron, E Amador; Amariutei, D; Anderson, R A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Ast, S; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barker, D; Barnum, S H; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J; Bauchrowitz, J; Bauer, Th S; Bebronne, M; Behnke, B; Bejger, M; Beker, M G; Bell, A S; Bell, C; Belopolski, I; Bergmann, G; Berliner, J M; Bersanetti, D; Bertolini, A; Bessis, D; Betzwieser, J; Beyersdorf, P T; Bhadbhade, T; Bilenko, I A; Billingsley, G; Birch, J; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, S; Bosi, L; Bowers, J; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brannen, C A; Brau, J E; Breyer, J; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Britzger, M; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Bulik, T; Bulten, H J; Buonanno, A; Buskulic, D; Buy, C; Byer, R L; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavagliá, M; Cavalier, F; Cavalieri, R; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Colombini, M; Constancio, M; Conte, A; Conte, R; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corsi, A; Costa, C A; Coughlin, M W; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Craig, K; Creighton, J D E; Creighton, T D; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daudert, B; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; De Rosa, R; Debreczeni, G; Degallaix, J; Del Pozzo, W; Deleeuw, E; Deléglise, S; Denker, T; Dent, T; Dereli, H; Dergachev, V; DeRosa, R; DeSalvo, R; Dhurandhar, S; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Díaz, M; Dietz, A; Dmitry, K; Donovan, F; Dooley, K L; Doravari, S; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dumas, J -C; Dwyer, S; Eberle, T; Edwards, M; Effler, A; Ehrens, P; Eichholz, J; Eikenberry, S S; Endröczi, G; Essick, R; Etzel, T; Evans, K; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W; Favata, M; Fazi, D; Fehrmann, H; Feldbaum, D; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R; Flaminio, R; Foley, E; Foley, S; Forsi, E; Fotopoulos, N; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fujimoto, M -K; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Garcia, J; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Gergely, L; Ghosh, S; Giaime, J A; Giampanis, S; Giardina, K D; Giazotto, A; Gil-Casanova, S; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Graef, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Griffo, C; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K E; Gustafson, E K; Gustafson, R; Hall, B; Hall, E; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hartman, M T; Haughian, K; Hayama, K; Heefner, J; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Holtrop, M; Hong, T; Hooper, S; Horrom, T; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hua, Z; Huang, V; Huerta, E A; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Iafrate, J; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jang, Y J; Jaranowski, P; Jiménez-Forteza, F; Johnson, W W; Jones, D; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Kasprzack, M; Kasturi, R; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufman, K; Kawabe, K; Kawamura, S; Kawazoe, F; Kéfélian, F; Keitel, D; Kelley, D B; Kells, W; Keppel, D G; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, B K; Kim, C; Kim, K
2013-01-01T23:59:59.000Z
Cosmic string cusps produce powerful bursts of gravitational waves (GWs). These bursts provide the most promising observational signature of cosmic strings. In this letter we report stringent limits on cosmic string models obtained from the analysis of 625 days of observation with the LIGO and Virgo GW detectors. A significant fraction of the cosmic string parameter space is ruled out. This result complements and improves existing limits from searches for a stochastic background of GWs using cosmic microwave background and pulsar timing data. In particular, if the size of loops is given by gravitational back-reaction, we place upper limits on the string tension $G\\mu$ below $10^{-8}$ in some regions of the cosmic string parameter space.
Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors
J. Aasi; J. Abadie; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; C. Adams; T. Adams; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; P. Ajith; B. Allen; A. Allocca; E. Amador Ceron; D. Amariutei; R. A. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. Ast; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; D. Barker; S. H. Barnum; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. Batch; J. Bauchrowitz; Th. S. Bauer; M. Bebronne; B. Behnke; M. Bejger; M. G. Beker; A. S. Bell; C. Bell; I. Belopolski; G. Bergmann; J. M. Berliner; D. Bersanetti; A. Bertolini; D. Bessis; J. Betzwieser; P. T. Beyersdorf; T. Bhadbhade; I. A. Bilenko; G. Billingsley; J. Birch; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; M. Blom; O. Bock; T. P. Bodiya; M. Boer; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; S. Bose; L. Bosi; J. Bowers; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; C. A. Brannen; J. E. Brau; J. Breyer; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; M. Britzger; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brückner; T. Bulik; H. J. Bulten; A. Buonanno; D. Buskulic; C. Buy; R. L. Byer; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavagliá; F. Cavalier; R. Cavalieri; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; D. E. Clark; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; M. Colombini; M. Constancio Jr.; A. Conte; R. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corsi; C. A. Costa; M. W. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; K. Craig; J. D. E. Creighton; T. D. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; B. Daudert; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; R. De Rosa; G. Debreczeni; J. Degallaix; W. Del Pozzo; E. Deleeuw; S. Deléglise; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. DeRosa; R. DeSalvo; S. Dhurandhar; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; M. Díaz; A. Dietz; K. Dmitry; F. Donovan; K. L. Dooley; S. Doravari; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; J. -C. Dumas; S. Dwyer; T. Eberle; M. Edwards; A. Effler; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endröczi; R. Essick; T. Etzel; K. Evans; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. Farr; M. Favata; D. Fazi; H. Fehrmann; D. Feldbaum; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. Fisher; R. Flaminio; E. Foley; S. Foley; E. Forsi; N. Fotopoulos; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; M. Frei; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; M. -K. Fujimoto; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; J. Garcia; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; L. Gergely; S. Ghosh; J. A. Giaime; S. Giampanis; K. D. Giardina; A. Giazotto; S. Gil-Casanova; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Graef; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; C. Griffo; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. E. Gushwa; E. K. Gustafson; R. Gustafson; B. Hall; E. Hall; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. T. Hartman; K. Haughian; K. Hayama; J. Heefner; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; S. Hild; D. Hoak; K. A. Hodge; K. Holt; M. Holtrop; T. Hong; S. Hooper; T. Horrom; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; Z. Hua; V. Huang; E. A. Huerta; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; J. Iafrate; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; Y. J. Jang; P. Jaranowski; F. Jiménez-Forteza; W. W. Johnson; D. Jones; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; M. Kasprzack; R. Kasturi; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kaufman; K. Kawabe; S. Kawamura; F. Kawazoe
2014-04-07T23:59:59.000Z
Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension $G\\mu$ below $10^{-8}$ in some regions of the cosmic string parameter space.
Jethva, H. T.; Torres, O.; Waquet, F.; Chand, Duli; Hu, Yong X.
2014-01-16T23:59:59.000Z
We inter-compare the above-cloud aerosol optical depth (ACAOD) of biomass burning plumes retrieved from different A-train sensors, i.e., MODIS, CALIOP, POLDER, and OMI. These sensors have shown independent capabilities to detect and retrieve aerosol loading above marine boundary layer clouds--a kind of situation often found over the Southeast Atlantic Ocean during dry burning season. A systematic one-to-one comparison reveals that, in general, all passive sensors and CALIOP-based research methods derive comparable ACAOD with differences mostly within 0.2 over homogeneous cloud fields. The 532-nm ACAOD retrieved by CALIOP operational algorithm is largely underestimated; however, it’s 1064-nm AOD when converted to 500 nm shows closer agreement to the passive sensors. Given the different types of sensor measurements processed with different algorithms, the close agreement between them is encouraging. Due to lack of adequate direct measurements above cloud, the validation of satellite-based ACAOD retrievals remains an open challenge. The inter-satellite comparison, however, can be useful for the relative evaluation and consistency check.
String theories as the adiabatic limit of Yang-Mills theory
Alexander D. Popov
2015-07-14T23:59:59.000Z
We consider Yang-Mills theory with a matrix gauge group $G$ on a direct product manifold $M=\\Sigma_2\\times H^2$, where $\\Sigma_2$ is a two-dimensional Lorentzian manifold and $H^2$ is a two-dimensional open disc with the boundary $S^1=\\partial H^2$. The Euler-Lagrange equations for the metric on $\\Sigma_2$ yield constraint equations for the Yang-Mills energy-momentum tensor. We show that in the adiabatic limit, when the metric on $H^2$ is scaled down, the Yang-Mills equations plus constraints on the energy-momentum tensor become the equations describing strings with a worldsheet $\\Sigma_2$ moving in the based loop group $\\Omega G=C^\\infty (S^1, G)/G$, where $S^1$ is the boundary of $H^2$. By choosing $G=R^{d-1, 1}$ and putting to zero all parameters in $\\Omega R^{d-1, 1}$ besides $R^{d-1, 1}$, we get a string moving in $R^{d-1, 1}$. In arXiv:1506.02175 it was described how one can obtain the Green-Schwarz superstring action from Yang-Mills theory on $\\Sigma_2\\times H^2$ while $H^2$ shrinks to a point. Here we also consider Yang-Mills theory on a three-dimensional manifold $\\Sigma_2\\times S^1$ and show that in the limit when the radius of $S^1$ tends to zero, the Yang-Mills action functional supplemented by a Wess-Zumino-type term becomes the Green-Schwarz superstring action.
Alternate retrieval technology demonstrations program - test report (ARD Environmental, Inc.)
Berglin, E.J.
1997-07-31T23:59:59.000Z
A prototype vehicle, control system, and waste and water scavenging system were designed and fabricated with essentially the full capabilities of the vehicle system proposed by ARD Environmental. A test tank mockup, including riser and decontamination chamber were designed and fabricated, and approximately 830 cubic feet of six varieties of waste simulants poured. The tests were performed by ARD Environmental personnel at its site in Laurel, Maryland, from 4/22/97 through 5/2/97. The capabilities tested were deployment and retrieval, extended mobility and productivity, the ability to operate the system using video viewing only, retrieval after simulated failure, and retrieval and decontamination. Testing commenced with deployment of the vehicle into the tank. Deployment was accomplished using a crane and auxiliary winch to position the vehicle and lower it through the decontamination chamber, into the 36`` diameter x 6` high riser, and touch down on the waste field in the tank. The initial mobility tests were conducted immediately after deployment, prior to sluicing, as the waste field exhibited the greatest amount of variation at this time. This test demonstrated the ability of the vehicle to maneuver over the simulated waste field, and the ability of the operator to work with only video viewing available. In addition, the ability of the vehicle to right itself after being turned on its side was demonstrated. The production rate was evaluated daily through the testing period by measuring the surface and estimating the amount of material removed. The test demonstrated the ability of the vehicle to reduce the waste surface using 400 psi (nominal) water jets, scavenge water and material from the work area, and move to any location, even in the relatively confined space of the 20` diameter test tank. In addition, the ability to sluice to a remote scavenging module was demonstrated. The failure mode test demonstrated the ability to retrieve a stuck vehicle by pulling on the tether, even if the vehicle wheels were locked or the vehicle was on its side. Line pull required to retrieve the vehicle was measured, and side load on the riser calculated from the line pull and line angles. Finally, the decontamination test demonstrated the ability to effectively clean the umbilical and vehicle. The issues addressed and resolved during the testing were: Feasibility of deploying a vehicle- based system, mobility, production rate and limitation of water in the tank during sluicing, mining strategy, operator efficiency, vehicle recovery, and decontamination. Water usage and waste removal rates were used to estimate the time and water usage requirements for cleaning a Hanford SST.
Resonant acoustic transducer and driver system for a well drilling string communication system
Chanson, Gary J. (Weston, MA); Nicolson, Alexander M. (Concord, MA)
1981-01-01T23:59:59.000Z
The acoustic data communication system includes an acoustic transmitter and receiver wherein low frequency acoustic waves, propagating in relatively loss free manner in well drilling string piping, are efficiently coupled to the drill string and propagate at levels competitive with the levels of noise generated by drilling machinery also present in the drill string. The transmitting transducer incorporates a mass-spring piezoelectric transmitter and amplifier combination that permits self-oscillating resonant operation in the desired low frequency range.
On Rotating and Oscillating Four-Spin Strings in AdS5 X S5
Kamal L. Panigrahi; Pabitra M. Pradhan
2012-10-26T23:59:59.000Z
We study rigidly rotating strings in AdS5 X S5 background with one spin along AdS5 and three angular momenta along S5. We find dispersion relations among various charges and interpret them as giant magnon and spiky string solutions in various limits. Further we present an example of oscillating string which oscillates in the radial direction of the AdS5 and at the same time rotates in S5.
On Rotating and Oscillating Four-Spin Strings in AdS5 X S5
Panigrahi, Kamal L
2012-01-01T23:59:59.000Z
We study rigidly rotating strings in AdS5 X S5 background with one spin along AdS5 and three angular momenta along S5. We find dispersion relations among various charges and interpret them as giant magnon and spiky string solutions in various limits. Further we present an example of oscillating string which oscillates in the radial direction of the AdS5 and at the same time rotates in S5.
Lectures on D-branes, tachyon condensation, and string field theory
Washington Taylor
2003-01-15T23:59:59.000Z
These lectures provide an introduction to the subject of tachyon condensation in the open bosonic string. The problem of tachyon condensation is first described in the context of the low-energy Yang-Mills description of a system of multiple D-branes, and then using the language of string field theory. An introduction is given to Witten's cubic open bosonic string field theory. The Sen conjectures on tachyon condensation in open bosonic string field theory are introduced, and evidence confirming these conjectures is reviewed.
Energy Distribution of a Black Hole Solution in Heterotic String Theory
I. Radinschi
2003-02-12T23:59:59.000Z
We calculate the energy distribution of a charged black hole solution in heterotic string theory in the M{\\o}ller prescription.
Idaho Waste Retrieval Facility Begins New Role | Department of Energy
Office of Environmental Management (EM)
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:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,Separation 23 362 of Thomas P.Oil, andEnergyEnvironmental CleanupReviewReform atof Wind Power |Retrieval
COMPLIANCE FOR HANFORD WASTE RETRIEVAL RADIOACTIVE AIR EMISSIONS
FM SIMMONS
2009-06-30T23:59:59.000Z
{sm_bullet} Since 1970, approximately 38,000 suspect transuranic (TRU) and TRU waste cont{approx}iners have been placed in retrievable storage on the Hanford Site in the 200Area's burial grounds. {sm_bullet} TRU waste is defined as waste containing greater than 100 nanocuries/gram of alpha emitting transuranic isotopes with half lives greater than 20 years. {sm_bullet} The United States currentl{approx}permanently disposes of TRU waste at the Waste Isolation Pilot Plant (WIPP).
Rapid automatic keyword extraction for information retrieval and analysis
Rose, Stuart J (Richland, WA); Cowley,; Wendy E (Richland, WA); Crow, Vernon L (Richland, WA); Cramer, Nicholas O (Richland, WA)
2012-03-06T23:59:59.000Z
Methods and systems for rapid automatic keyword extraction for information retrieval and analysis. Embodiments can include parsing words in an individual document by delimiters, stop words, or both in order to identify candidate keywords. Word scores for each word within the candidate keywords are then calculated based on a function of co-occurrence degree, co-occurrence frequency, or both. Based on a function of the word scores for words within the candidate keyword, a keyword score is calculated for each of the candidate keywords. A portion of the candidate keywords are then extracted as keywords based, at least in part, on the candidate keywords having the highest keyword scores.
Integral Monitored Retrievable Storage (MRS) Facility conceptual design report
None
1985-09-01T23:59:59.000Z
In April 1985, the Department of Energy (DOE) selected the Clinch River site as its preferred site for the construction and operation of the monitored retrievable storage (MRS) facility (USDOE, 1985). In support of the DOE MRS conceptual design activity, available data describing the site have been gathered and analyzed. A composite geotechnical description of the Clinch River site has been developed and is presented herein. This report presents Clinch River site description data in the following sections: general site description, surface hydrologic characteristics, groundwater characteristics, geologic characteristics, vibratory ground motion, surface faulting, stability of subsurface materials, slope stability, and references. 48 refs., 35 figs., 6 tabs.
A computerized storage and retrieval system for water quality data
Sparr, Ted M
1969-01-01T23:59:59.000Z
processing run, The system designer cannot assure data base credibility if machine failure occurs during processing. For example, a par- tially completed data input action can leave directories which are no longer consistent with data that they index...~ a, I D E Col: 4a ' E b e e (Me', aber) A8STRACT A Computerized Storage and Retrieval System for Water Quality Data. (August l969) Ted H. Sparr, B. A. , Ohio Wesleyan Univereity; Directed by; Dr. Roy W, Harm, Jr, Automated data storage...
IMAGE RETRIEVAL OVER NETWORKS: ANT ALGORITHM FOR LONG TERM ACTIVE David Picard1
IMAGE RETRIEVAL OVER NETWORKS: ANT ALGORITHM FOR LONG TERM ACTIVE LEARNING David Picard1 , Arnaud of relevant images from the interaction with the user. We carr
Amy Peng; Mattias Johnsson; Joseph J. Hope
2004-11-09T23:59:59.000Z
We examine in detail an alternative method of retrieving the information written into an atomic ensemble of three-level atoms using electromagnetically induced transparency. We find that the behavior of the retrieved pulse is strongly influenced by the relative collective atom-light coupling strengths of the two relevant transitions. When the collective atom-light coupling strength for the retrieval beam is the stronger of the two transitions, regeneration of the stored pulse is possible. Otherwise, we show the retrieval process can lead to creation of soliton-like pulses.
Adaptive Image Retrieval using a Graph Model for Semantic Feature Integration
Urban, J.
Urban,J. Jose,J.M. Proceedings of the 8th ACM international workshop on Multimedia information retrieval pp 117-26 ACM Press
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-06-03T23:59:59.000Z
We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably.
Open string moduli in Kachru-Kallosh-Linde-Trivedi compactifications
Aharony, Ofer; Antebi, Yaron E.; Berkooz, Micha [Department of Particle Physics, Weizmann Institute of Science, Rehovot 76100 (Israel)
2005-11-15T23:59:59.000Z
In the Kachru-Kallosh-Linde-Trivedi (KKLT) de-Sitter construction one introduces an anti-D3-brane that breaks the supersymmetry and leads to a positive cosmological constant. In this paper we investigate the open string moduli associated with this anti-D3-brane, corresponding to its position on the S{sup 3} at the tip of the deformed conifold. We show that in the KKLT construction these moduli are very light, and we suggest a possible way to give these moduli a large mass by putting orientifold planes in the KKLT ''throat.''.
String black hole: Can it be a particle accelerator ?
Sharmanthie Fernando
2014-08-21T23:59:59.000Z
In this paper we have studied the possibility of the center-of-mass energy of two particles colliding near the horizon of a static charged black hole in string theory. Various cases corresponding to the electric charge and the angular momentum of the particles were considered. The studies were done for the general black hole as well as for the extreme black hole. There were two scenarios where the center-of-mass energy reach very large values if the appropriate properties of the particles are chosen.
Size scaling of self gravitating polymers and strings
Kawamoto, Shoichi
2015-01-01T23:59:59.000Z
We study a statistical ensemble of a single polymer with self gravitational interaction. This is a model of a gravitating string --- the precursor of a black hole. We analyze averaged sizes by mean field approximations with an effective Hamiltonian a la Edwards with Newtonian potential as well as a contact repulsive interaction. We find that there exists a certain scaling region where the attractive and the repulsive forces balance out. The repulsive interaction pushes the critical gravitational coupling to a larger value, at which the size of a polymer becomes comparable to its Schwarzschild radius, and as a result the size of the corresponding black hole increases considerably.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth; Turner, William Evans; Burgess, Daniel E; Perry, Carl Allison
2014-03-04T23:59:59.000Z
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2008-05-27T23:59:59.000Z
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2007-05-22T23:59:59.000Z
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2011-08-16T23:59:59.000Z
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
System and method for damping vibration in a drill string
Wassell, Mark Ellsworth (Kingswood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)
2012-08-14T23:59:59.000Z
A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.
Exact results on ABJ theory and the refined topological string
Masazumi Honda; Kazumi Okuyama
2014-07-22T23:59:59.000Z
We study the partition function of the ABJ theory, which is the N=6 superconformal Chern-Simons matter theory with gauge group U(N)xU(N+M) and Chern-Simons levels (k,-k). We exactly compute the ABJ partition function on a three sphere for various k, M and N via the Fermi gas approach. By using these exact data, we show that the ABJ partition function is completely determined by the refined topological string on local P^1 x P^1, including membrane instanton effects in the M-theory dual.
On higher spins and the tensionless limit of String Theory
A. Sagnotti; M. Tsulaia
2004-01-09T23:59:59.000Z
We discuss string spectra in the low-tension limit using the BRST formalism, with emphasis on the role of triplets of totally symmetric tensors and spinor-tensors and their generalizations to cases with mixed symmetry and to (A)dS backgrounds. We also present simple compensator forms of the field equations for individual higher-spin gauge fields that display the {unconstrained} gauge symmetry of a previous non-local construction and reduce upon partial gauge fixing to the (Fang-)Fronsdal equations. For Bose fields we also show how a local Lagrangian formulation with {unconstrained} gauge symmetry is determined by a previous BRST construction.
The anomaly-free quantization of two-dimensional relativistic string. I
S. N. Vergeles
1998-12-21T23:59:59.000Z
An anomaly-free quantum theory of a relativistic string is constructed in two-dimensional space-time. The states of the string are found to be similar to the states of a massless chiral quantum particle. This result is obtained by generalizing the concept of an ``operator'' in quantum field theory.
An Efficient Index Structure for String Databases Tamer Kahveci Ambuj K. Singh
Kahveci, Tamer
are genetic data, web data, and event se- quences. Since the size of such databases grows exponentially online access and search capabilities. String data applications generally involve very large databasesAn Efficient Index Structure for String Databases Tamer Kahveci Ambuj K. Singh Department
DRILL-STRING NONLINEAR DYNAMICS ACCOUNTING FOR DRILLING FLUID T. G. Ritto
Boyer, Edmond
;1. INTRODUCTION A drill-string is a slender structure used in oil wells to penetrate the soil in search of oilDRILL-STRING NONLINEAR DYNAMICS ACCOUNTING FOR DRILLING FLUID T. G. Ritto R. Sampaio thiagoritto Descartes, 77454 Marne-la-Vallée, France Abstract. The influence of the drilling fluid (or mud) on the drill
Wavelet domain Bayesian denoising of string signal in the cosmic microwave background
D. K. Hammond; Y. Wiaux; P. Vandergheynst
2009-04-27T23:59:59.000Z
An algorithm is proposed for denoising the signal induced by cosmic strings in the cosmic microwave background (CMB). A Bayesian approach is taken, based on modeling the string signal in the wavelet domain with generalized Gaussian distributions. Good performance of the algorithm is demonstrated by simulated experiments at arcminute resolution under noise conditions including primary and secondary CMB anisotropies, as well as instrumental noise.