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 ...
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.
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for reduction in mixed waste generation Pump Oil Substitution 51 Hazardous Waste / Industrial Waste $3,520 $6 with the subsequent clean up costs ($15,000). Hydraulic Oil Product Substitution 3,000 Industrial Waste $26,000 $0 $26WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED, REUSED, RECYCLED OR CONSERVED IN 2003 WASTE TYPE
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. Removed grit and sludge are mixed with the waste oil. Photon-counting spectrofluorimeter Substitution 54 or composted at the stump dump. Plant Engineering grounds vehicle wash system * Waste minimization 8,000 OilsWASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED, REUSED, RECYCLED OR CONSERVED IN 2007 WASTE TYPE
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
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.
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.
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...
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.
Microscopic unitary description of tidal excitations in high-energy string-brane collisions
Giuseppe D'Appollonio; Paolo Di Vecchia; Rodolfo Russo; Gabriele Veneziano
2013-11-15T23:59:59.000Z
The eikonal operator was originally introduced to describe the effect of tidal excitations on higher-genus elastic string amplitudes at high energy. In this paper we provide a precise interpretation for this operator through the explicit tree-level calculation of generic inelastic transitions between closed strings as they scatter off a stack of parallel Dp-branes. We perform this analysis both in the light-cone gauge, using the Green-Schwarz vertex, and in the covariant formalism, using the Reggeon vertex operator. We also present a detailed discussion of the high energy behaviour of the covariant string amplitudes, showing how to take into account the energy factors that enhance the contribution of the longitudinally polarized massive states in a simple way.
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.
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.
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.
A Description of the Agriculture and Type-of-Farming Areas in Texas.
Bonnen, C. A. (Clarence Alfred); Thibodeaux, B. H. (Ben Hur)
1937-01-01T23:59:59.000Z
LIBRARY, A & M COLLEGE, CAMPUS. R82-537-20m TEXAS AGRICULTURAL EXPERIMENT STATION A. B. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS BULLETIN NO. 544 JUNE, 1937 IN COOPERATION WITH THE DIVISION OF FARM MANAGEMEN AND COSTS, BUREAU... OF' AGRICULTURAL ECONOMICS, U. S. DEPARTMENT OF AGRICULTURE A DESCRIPTION OF THE AGRICULTURE AND TYPE- OF-FARMING AREAS IN TEXAS AGRICULTURAL AND MECHANICAL COLLEGE OF TEXAS T. 0. WALTON, President Texas is primarily an rcgricultural State...
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.
Rudolph, Sebastian; Hitzler, Pascal
2012-01-01T23:59:59.000Z
We propose a novel, type-elimination-based method for reasoning in the description logic SHIQbs including DL-safe rules. To this end, we first establish a knowledge compilation method converting the terminological part of an ALCIb knowledge base into an ordered binary decision diagram (OBDD) which represents a canonical model. This OBDD can in turn be transformed into disjunctive Datalog and merged with the assertional part of the knowledge base in order to perform combined reasoning. In order to leverage our technique for full SHIQbs, we provide a stepwise reduction from SHIQbs to ALCIb that preserves satisfiability and entailment of positive and negative ground facts. The proposed technique is shown to be worst case optimal w.r.t. combined and data complexity and easily admits extensions with ground conjunctive queries.
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).
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.
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.
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.
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.
A new 5d description of 6d D-type minimal conformal matter
Hirotaka Hayashi; Sung-Soo Kim; Kimyeong Lee; Masato Taki; Futoshi Yagi
2015-06-18T23:59:59.000Z
We propose a new 5d description of the circle-compactified 6d $(D_{N+4}, D_{N+4})$ minimal conformal matter theory which can be approached by the 6d $\\mathcal{N}=(1,0)$ $Sp(N)$ gauge theory with $N_f=2N+8$ flavors and one tensor multiplet. Compactifying the brane set-up for the 6d theory, we arrive at a 5-brane Tao diagram for 5d $\\mathcal{N}=1$ $SU(N+2)$ theory of the vanishing Chern-Simons level with $2N+8$ flavors. We conjecture that the 6d theory is recovered as the UV fixed point of this 5d theory. We show that the global symmetry of this 5d theory is $SO(4N+16)$ identical to that of the 6d theory by analyzing the 7-brane monodromy. By using the Tao diagram, we also find the instanton fugacity is exactly given by the circle radius. By decoupling flavors in this 5d theory, one can obtain all the 5d $SU(N+2)$ gauge theories of various Chern-Simons levels and corresponding enhanced global symmetries at the 5d UV fixed point.
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.
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.
and definitions used in digital logic design: notation, number systems, difference between analog and digital system, specification and implementation, analysis and design, design cycle, CAD tools, combinational-level description of a digital system into a binary description of it (ABET Outcomes: A,M) 2. Analyze and design
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.
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.
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.
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.
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
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.
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.
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.
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.
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.
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).
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.
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.
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.
Description of CBECS Building Types
Gasoline and Diesel Fuel Update (EIA)
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 23 362 334 318 706 802Decade Year-0 Year-1 Year-2 Year-3KansasRobertFTotalThousand Cubic Feet)D
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.
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.
C. G. Bollini; A. L. De Paoli; M. C. Rocca
2010-02-12T23:59:59.000Z
In this paper we show that Ultradistributions of Exponential Type (UET) are appropriate for the description in a consistent way world sheet superstring and superstring field theories. A new Lagrangian for the closed world sheet superstring is obtained. We also show that the superstring field is a linear superposition of UET of compact support (CUET), and give the notion of anti-superstring. We evaluate the propagator for the string field, and calculate the convolution of two of them.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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...
Exeter, University of
due to natural or human impacts, such as hurricanes or dredging. Further, resource mapping be determined. It is less costly and time-consuming to map the benthic resources by major habitat type, although
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.
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.
THREEPARTICLE BOSE--EINSTEIN CORRELATIONS a sensitive probe for Lund string fragmentation
Ringnér, Markus
THREEPARTICLE BOSE--EINSTEIN CORRELATIONS a sensitive probe for Lund string fragmentation M with respect to the jet axis in e + e \\Gamma annihilation, arises naturally in a model for BoseEinstein , and is a description of some features of the model for Bose--Einstein (BE) correlations developed in 2 (an extension
Irais Bautista; Jorge Dias de Deus; José Guilherme Milhano; Carlos Pajares
2012-04-06T23:59:59.000Z
We show that the dependence of the charged particle multiplicity on the centre-of-mass energy of the collision is, in the String Percolation Model, driven by the same power law behavior in both proton-proton and nucleus- nucleus collisions. The observed different growths are a result of energy- momentum constraints that limit the number of formed strings at low en- ergy. Based on the very good description of the existing data, we provide predictions for future high energy LHC runs.
Bautista, Irais; Milhano, José Guilherme; Pajares, Carlos
2012-01-01T23:59:59.000Z
We show that the dependence of the charged particle multiplicity on the centre-of-mass energy of the collision is, in the String Percolation Model, driven by the same power law behavior in both proton-proton and nucleus- nucleus collisions. The observed different growths are a result of energy- momentum constraints that limit the number of formed strings at low en- ergy. Based on the very good description of the existing data, we provide predictions for future high energy LHC runs.
C. Hoehne; F. Puehlhofer; R. Stock
2005-07-25T23:59:59.000Z
We argue that the shape of the system-size dependence of strangeness production in nucleus-nucleus collisions can be understood in a picture that is based on the formation of clusters of overlapping strings. A string percolation model combined with a statistical description of the hadronization yields a quantitative agreement with the data at $\\sqrt{s_{NN}}=17.3$ GeV. The model is also applied to RHIC energies.
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.
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.
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Oak Ridge Institute for Science Education Job Description No job description found Career Center Employment Questions? Email us at work@orau.org...
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.
WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED,
to the manufacturer . Replaced with energy efficient light emitting diode (LED) signs. Project reduced risk of tritium
WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED,
on the cost of one mercury spill and clean-up event. PCB Oils Retrofill 1,200 Hazardous Waste $2,850 $3,450 $2 the life expentency on a $100,000 piece of equipment. PCB Oils Removal 3,110 Hazardous Waste $6,220 $10 generation Pump Oil Substitution 51 Hazardous Waste / Industrial Waste $3,520 $0 $3,520 Replaced oil
WASTE DESCRIPTION TYPE OF PROJECT POUNDS REDUCED,
Fuel oil and Turkey Based Biofuel Energy Rocovery 12,000 Industrial Waste $30,000 $500 $29,500 1500 re-distills the solvent when dirty. The removed grit and sludge is mixed in with the waste oil Wash * Waste Minimization 8,000 oils/grease to soils $16,000 $1,000 $16,000 This is a multi
Broader source: Energy.gov [DOE]
STEP Intern Job Description, from the Tool Kit Framework: Small Town University Energy Program (STEP).
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.
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.
Improving the Infra-red of Holographic Descriptions of QCD
Nick Evans; Andrew Tedder; Tom Waterson
2007-01-03T23:59:59.000Z
A surprisingly good holographic description of QCD can be obtained from naive five dimensional gauge theory on a truncated AdS space. We seek to improve the infra-red description of QCD in such models by using a more sophisticated metric and an action derived from string theory duals of chiral symmetry breaking. Our metric is smooth into the infra-red and the chiral condensate is a prediction of the dynamics. The theory reproduces QCD meson data at the 10% level.
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.
$O(d,d)$-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.
YUCCA MOUNTAIN SITE DESCRIPTION
A.M. Simmons
2004-04-16T23:59:59.000Z
The ''Yucca Mountain Site Description'' summarizes, in a single document, the current state of knowledge and understanding of the natural system at Yucca Mountain. It describes the geology; geochemistry; past, present, and projected future climate; regional hydrologic system; and flow and transport within the unsaturated and saturated zones at the site. In addition, it discusses factors affecting radionuclide transport, the effect of thermal loading on the natural system, and tectonic hazards. The ''Yucca Mountain Site Description'' is broad in nature. It summarizes investigations carried out as part of the Yucca Mountain Project since 1988, but it also includes work done at the site in earlier years, as well as studies performed by others. The document has been prepared under the Office of Civilian Radioactive Waste Management quality assurance program for the Yucca Mountain Project. Yucca Mountain is located in Nye County in southern Nevada. The site lies in the north-central part of the Basin and Range physiographic province, within the northernmost subprovince commonly referred to as the Great Basin. The basin and range physiography reflects the extensional tectonic regime that has affected the region during the middle and late Cenozoic Era. Yucca Mountain was initially selected for characterization, in part, because of its thick unsaturated zone, its arid to semiarid climate, and the existence of a rock type that would support excavation of stable openings. In 1987, the United States Congress directed that Yucca Mountain be the only site characterized to evaluate its suitability for development of a geologic repository for high-level radioactive waste and spent nuclear fuel.
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.
Hagedorn String Thermodynamics in Curved Spacetimes and near Black Hole Horizons
Thomas G. Mertens
2015-06-25T23:59:59.000Z
This thesis concerns the study of high-temperature string theory on curved backgrounds, generalizing the notions of Hagedorn temperature and thermal scalar to general backgrounds. Chapter 2 contains a review on string thermodynamics in flat space, setting the stage. Chapters 3 and 4 contain the detailed study of the random walk picture in a general curved background. Chapters 5 and 6 then apply this to Rindler space, the near-horizon approximation of a generic (uncharged) black hole. Chapters 7 and 8 contain a study of the AdS3 and BTZ WZW models where we study the thermal spectrum and the resulting random walk picture that emerges. Chapters 9 and 10 attempt to draw general conclusions from the study of the two specific examples earlier: we draw lessons on string thermodynamics in general and on (perturbative) string thermodynamics around black hole horizons. For the latter, we point out a possible link to the firewall paradox. Finally, chapter 11 contains a detailed discussion on the near-Hagedorn (and high-energy) stress tensor in a generic spacetime, the results of which are applied to provide a description of the Bekenstein-Hawking entropy in terms of long string equilibration.
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.
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.
Harms, Kyle E.
JOB DESCRIPTION POSITION DATA Position Number: Title Description: Title Code: Title Level: Employee: _____ Job Summary: Overview of position and its purpose. Select One Select One Select One Select One Select One Select One Select One Select One Select One Select One #12;Office of Human Resource Management Job
Marketing Plan Company Description
Dahl, David B.
Marketing Plan Company Description: Consumer company that provides a product to helps boost Marketing Swat Team Project Description and Deliverables: The team will Identify the best online vehicles of promotions from YouTube celebs, co- marketing with related businesses, affiliate marketing, cross marketing
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.
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.
Job Description Library Create a New Job Description
Pulfrey, David L.
UBC eRecruit Job Description Library #12;Page 4 Create a New Job Description Navigation: Job Description Library>Add/Edit/Copy Job Descriptions Step 1: Use this page to enter preliminary Job Description, Location: Enter the codes associated with the department. Employment Group, Job Family, Job Code/Classification
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.
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.
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)
Lecture notes on thermodynamics of ideal string gases and its application in cosmology
Lihui Liu
2014-12-05T23:59:59.000Z
In these lecture notes I give a pedagogical introduction to the thermodynamics of ideal string gases. The computation of thermodynamic quantities in the canonical ensemble formalism will be shown in detail with explicit examples. Attention will be given mainly to the thermodynamical consequences of string degrees of freedom, where I will especially address i) the Hagedorn temperature, a critical temperature above which the canonical ensemble description breaks down, which can be the onset point of some instability of the string gas; ii) the phase structure arising from compactification, embodied in the moduli-dependence of the Helmholtz free energy, which corrects the tree-level vacuum and can provide mechanism for moduli stabilization. Then I will briefly explain the implementation of string gas thermodynamics in cosmology, showing a simple example which gives rise to a radiation-dominated early universe. Further phenomenological issues and open questions will be discussed qualitatively with references indicated, including the Hagedorn instability in the resolution of the initial singularity, moduli stabilization, generation of hierarchy, radiative symmetry breaking and primordial cosmological fluctuations.
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.
University of Iceland Description
Bristol, University of
University of Iceland __________________________________________________________________________________________ Description The University of Iceland (Háskóli Íslands) is a state university founded in 1911. Today, the University of Iceland serves a nation of approximately 320,000 people and provides instruction for some 15
Clean Transportation Internship Description
Clean Transportation Internship Description The NC Solar Center at North Carolina State University to other ongoing projects by focusing on time-sensitive tasks. While the main thrust of this internship
New spin(7) holonomy metrics admitting G{sub 2} holonomy reductions and M-theory/type-IIA dualities
Salur, S. [Department of Mathematics University of Rochester, Rochester, New York, 14627 (United States); Santillan, O. [Hamilton Mathematics Institute and School of Mathematics Trinity College, Dublin 2 (Ireland)
2009-04-15T23:59:59.000Z
As is well known, when D6 branes wrap a special Lagrangian cycle on a noncompact Calabi-Yau threefold in such a way that the internal string frame metric is a Kaehler one there exists a dual description, which is given in terms of a purely geometrical 11-dimensional background with an internal metric of G{sub 2} holonomy. It is also known that when D6 branes wrap a coassociative cycle of a noncompact G{sub 2} manifold in the presence of a self-dual two-form strength the internal part of the string frame metric is conformal to the G{sub 2} metric and there exists a dual description, which is expressed in terms of a purely geometrical 11-dimensional background with an internal noncompact metric of spin(7) holonomy. In the present work it is shown that any G{sub 2} metric participating in the first of these dualities necessarily participates in one of the second type. Additionally, several explicit spin(7) holonomy metrics admitting a G{sub 2} holonomy reduction along one isometry are constructed. These metrics can be described as R fibrations over a 6-dimensional Kaehler metric, thus realizing the pattern spin(7){yields}G{sub 2}{yields}(Kahler) mentioned above. Several of these examples are further described as fibrations over the Eguchi-Hanson gravitational instanton and, to the best of our knowledge, have not been previously considered in the literature.
Original Workshop Proposal and Description
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and Description Original Workshop Proposal and Description Visualization Requirements for Computational Science and Engineering Applications Proposal for a DoE Workshop to Be Held...
The Classical Exchange Algebra of AdS5 x S5 String Theory
Marc Magro
2009-01-07T23:59:59.000Z
The classical exchange algebra satisfied by the monodromy matrix of AdS5 x S5 string theory in the Green-Schwarz formulation is determined by using a first-order Hamiltonian formulation and by adding to the Bena-Polchinski-Roiban Lax connection terms proportional to constraints. This enables in particular to show that the conserved charges of this theory are in involution. This result is obtained for a general world-sheet metric. The same exchange algebra is obtained within the pure spinor description of AdS5 x S5 string theory. These results are compared to the one obtained by A. Mikhailov and S. Schaefer-Nameki for the pure spinor formulation.
Dirichlet branes and nonperturbative aspects of supersymmetric string and gauge theories
Yin, Zheng
1999-05-01T23:59:59.000Z
In chapter 1 the author reviews some elements of string theory relevant to the rest of this report. He touches on both the classical, i.e. perturbative, string physics before D-branes rise to prominence, and some of the progresses they brought forth. In chapter 2 he proceeds to give an exact algebraic formulation of D-branes in curved spaces. This allows one to classify them in backgrounds of interest and study their geometric properties. He applies this formalism to string theory on Calabi-Yau and other supersymmetry preserving manifolds. Then he studies the behavior of the D-branes under mirror symmetry in chapter 3. Mirror symmetry is known to be a symmetry of string theory perturbatively. He finds evidence for its nonperturbative validity when D-branes are also considered and compute some dynamical consequences. In chapter 4 he turns to examine the consistency of curved and/or intersecting D-brane configurations. They have been used recently to extract information about the field theories that arise in certain limits. It turns out that there are potential quantum mechanical inconsistencies associated with them. What saves the day are certain subtle topological properties of D-branes. This resolution has implications for the conserved charges carried by the D-branes, which he computes for the cases studied in chapter 2. In chapter 5 he uses intersecting brane configurations to study three dimensional supersymmetric gauge theories. There is also a mirror symmetry there that, among other things, exchanges classical and quantum mechanical quantities of a (mirror) pair of theories. It has an elegant realization in term of a symmetry of string theory involving D-branes. The author employs it to study a wide class of 3d models. He also predicts new mirror pairs and unconventional 3d field theories without Lagrangian descriptions.
Ritchie, L.T.; Alpert, D.J.; Burke, R.P.; Johnson, J.D.; Ostmeyer, R.M.; Aldrich, D.C.; Blond, R.M.
1984-03-01T23:59:59.000Z
The CRAC2 computer code is a revised version of CRAC (Calculation of Reactor Accident Consequences) which was developed for the Reactor Safety Study. This document provides an overview of the CRAC2 code and a description of each of the models used. Significant improvements incorporated into CRAC2 include an improved weather sequence sampling technique, a new evacuation model, and new output capabilities. In addition, refinements have been made to the atmospheric transport and deposition model. Details of the modeling differences between CRAC2 and CRAC are emphasized in the model descriptions.
ELECTRICAL SUPPORT SYSTEM DESCRIPTION DOCUMENT
S. Roy
2004-06-24T23:59:59.000Z
The purpose of this revision of the System Design Description (SDD) is to establish requirements that drive the design of the electrical support system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience/users are design engineers. This type of SDD both ''leads'' and ''trails'' the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. The SDD trails the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to electrical support systems are obtained from the ''Project Functional and Operational Requirements'' (F&OR) (Siddoway 2003). Other requirements to support the design process have been taken from higher-level requirements documents such as the ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), and fire hazards analyses. The above-mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canon and Leitner 2003) requirements. This SDD contains several appendices that include supporting information. Appendix B lists key system charts, diagrams, drawings, and lists, and Appendix C includes a list of system procedures.
ELECTRICAL POWER SYSTEM DESCRIPTION DOCUMENT
M. Maniyar
2004-06-22T23:59:59.000Z
The purpose of this revision of the System Description Document (SDD) is to establish requirements that drive the design of the electrical power system and their bases to allow the design effort to proceed to License Application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience are design engineers. This type of SDD leads and follows the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential to performing the design process. This SDD follows the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. Functional and operational requirements applicable to this system are obtained from ''Project Functional and Operational Requirements'' (F&OR) (Siddoway, 2003). Other requirements to support the design process have been taken from higher level requirements documents such as ''Project Design Criteria Document'' (PDC) (Doraswamy 2004), the fire hazards analyses, and the preclosure safety analysis. The above mentioned low-level documents address ''Project Requirements Document'' (PRD) (Canori and Leitner 2003) requirements. This SDD includes several appendices with supporting information. Appendix B lists key system charts, diagrams, drawings, and lists; and Appendix C is a list of system procedures.
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.
Entrepreneurship Company Description
Dahl, David B.
business startups and acquisitions within a business incubator/accelerator model. Students will be assigned summary write-up and/or business model creation - Pro forma financial statements - Market research report Project Description and Deliverables: Assist in developing a business plan, identifying an optimum entry
Market Research Company Description
Dahl, David B.
development - Market research for enterprise and education adoption - Plan and execute a company-wide pingMarket Research Company Description: A company focused on developing web-based graphical and future products and then develop the necessary strategies and collateral to stay on the bleeding edge
November 2001 Program Description
LBNL-44789 November 2001 Program Description A PC Program WINDOW 5.0 User Manual For Analyzing November 2001 WINDOW 5.0 User Manual Robin Mitchell, Christian Kohler, and Dariush Arasteh Windows, California Dragan Curcija Carli, Inc Amherst, Massachusetts November 2001 © Regents of the University
Title: Marketing Assistant Description
Schweik, Charles M.
Title: Marketing Assistant Description: The UMass Amherst Career Services Office is searching for a student interested in marketing. The Marketing Assistant will work closely with our in-office marketing Brainstorm new and exciting marketing strategies, including social media Participate and contribute
Accounting Projects Company Description
Dahl, David B.
Accounting Projects Company Description: CPA firm performing accounting services, bookkeeping for multiple years, starting with the 2008 calendar year, using QuickBooks accounting software. Bank and credit card statements will be used for multiple checking, savings, and credit card accounts to capture data
Competitor Analysis Company Description
Dahl, David B.
's financial information, strategies, geographic concentration, product line strength, and brand strength of leading HR Information System providers including pricing, product features, and market segment In India Project Description and Deliverables: We are looking to gain detailed information on the recent
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.
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.
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.
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.
Writing Effective Job Descriptions What is a Job Description?
Weaver, Harold A. "Hal"
Writing Effective Job Descriptions #12;What is a Job Description? A clear explanation of a job and promoting employees) #12;Writing Effective Job Descriptions Identify what needs to be done, how work is to be performed, what equipment will be used, what working conditions are Describe the Job Define Skills
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.
ChalkBoard: A Functional Image Description Language and Its Practical Applications
Matlage, Kevin
2011-04-21T23:59:59.000Z
.1 Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . 63 6.2 Transformation Algebra . . . . . . . . . . . . . . . . . . . . . . . 66 6.3 Indexed AST Improvements . . . . . . . . . . . . . . . . . . . . . 70 6.4 List Example.... The basic types in Haskell are pretty much the same as you would nd in most language. There are Int, Float, Bool, String, and many other fundamental types commonly found in most languages. In Haskell, however, these types can be combined and extended in a...
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.
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.
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)
Student Internship Programs Program Description
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Student Internship Programs Program Description The objective of the Laboratory's student internship programs is to provide students with opportunities for meaningful hands- on...
Clinical Rotation Descriptions-2013 Clinical Rotation Description Forms the Student
Sheridan, Jennifer
Clinical Rotation Descriptions- 2013 Clinical Rotation Description Forms the Student Completes:1 with a PT 2 from rotation (3), allowing the PT 2 to teach the PT 1. GAs * at end of experience, Clinical Performance Evaluation, Physical Therapy Student Evaluation: Clinical Experience and Instruction 1 page form
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.
MESOSCALE DESCRIPTION OF DEFECTED MATERIALS
Vinals, Jorge
MESOSCALE DESCRIPTION OF DEFECTED MATERIALS Jorge Vi~nals School of Physics and Astronomy. Laughlin) Small but finite wavenumber and finite frequency ("mesoscale") response functions and transport;MESOSCALE DESCRIPTION B B B B B B B A B A B A A B B A A A A BB A B Microscopic Mesoscopic Macroscopic vn
Waste Description Type of Project Pounds Reduced, Reused,
media Landfill 9,690,000 Low-level Radiological waste $4,000,000 $755,000 $3,245,000 Processing, treatment, and disposal of sewage sludge and sand filter media from the BNL Sewage Treatment Facility--this process removed all low-level radioactive contaminants from the operating facility. The sludge can now
Property:Description of Camera Types | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousPlasmaP a gHigh PlainsOttawa, Ontario:Information PropertyPropertyform ViewProperty EditProperty
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 $\\Upsilon(5S)$.
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.
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.
Range descriptions for the spherical mean Radon transform
M. Agranovsky; P. Kuchment; E. T. Quinto
2006-09-02T23:59:59.000Z
The transform considered in the paper averages a function supported in a ball in $\\RR^n$ over all spheres centered at the boundary of the ball. This Radon type transform arises in several contemporary applications, e.g. in thermoacoustic tomography and sonar and radar imaging. Range descriptions for such transforms are important in all these areas, for instance when dealing with incomplete data, error correction, and other issues. Four different types of complete range descriptions are provided, some of which also suggest inversion procedures. Necessity of three of these (appropriately formulated) conditions holds also in general domains, while the complete discussion of the case of general domains would require another publication.
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.
Kammen, Daniel M.
, Berkeley. SWITCH Model Description 1. Study Years, Months, Dates and Hours To simulate power system1 SWITCH Model AND Data Description: 2050 Timeframe................................................ 2 SWITCH Model Description
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
SEDIMENT DESCRIPTIONS R/V POLAR DUKE
SEDIMENT DESCRIPTIONS R/V POLAR DUKE CRUISE IV, 1989 #12;#12;DESCRIPTIONS OF SEDIMENT RECOVERED R. Janecek Sediment Descriptions Dennis S. Cassidy F. Amisar Kaharoeddin Xinlan Liu Technical ........................................................... 10 SEDIMENT CLASSIFICATION ..................................................... 11 Pelagic Sediments
SEDIMENT DESCRIPTIONS R/V POLAR DUKE
#12;#12;SEDIMENT DESCRIPTIONS R/V POLAR DUKE 1991 #12;#12;DESCRIPTIONS OF SEDIMENT RECOVERED Sediment Descriptions Xinlan Liu Technical Assistant Carl Painter Antarctic Marine Geology Research ........................................................... 15 SEDIMENT CLASSIFICATION ..................................................... 16 Pelagic Sediments
SEDIMENT DESCRIPTIONS R/V Polar Duke
#12;#12;SEDIMENT DESCRIPTIONS for R/V Polar Duke Cruise VI, 1988 #12;#12;DESCRIPTIONS OF SEDIMENT Sediment Descriptions Matthew G. Curren and J. Alexis Howell Antarctic Marine Geology Research Facility...............................................................................................11 SEDIMENT CLASSIFICATION
SEDIMENT DESCRIPTIONS R/V POLAR DUKE
#12;#12;SEDIMENT DESCRIPTIONS R/V POLAR DUKE CRUISE III, 1988 #12;#12;DESCRIPTIONS OF SEDIMENT and Thomas R. Janecek Sediment Descriptions Dennis S. Cassidy Amisar Kaharoeddin Xinlan Liu Technical ........................................................... 20 SEDIMENT CLASSIFICATION ..................................................... 21 Details
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.
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.
CANISTER HANDLING FACILITY DESCRIPTION DOCUMENT
J.F. Beesley
2005-04-21T23:59:59.000Z
The purpose of this facility description document (FDD) is to establish requirements and associated bases that drive the design of the Canister Handling Facility (CHF), which will allow the design effort to proceed to license application. This FDD will be revised at strategic points as the design matures. This FDD identifies the requirements and describes the facility design, as it currently exists, with emphasis on attributes of the design provided to meet the requirements. This FDD is an engineering tool for design control; accordingly, the primary audience and users are design engineers. This FDD is part of an iterative design process. It leads the design process with regard to the flowdown of upper tier requirements onto the facility. Knowledge of these requirements is essential in performing the design process. The FDD follows the design with regard to the description of the facility. The description provided in this FDD reflects the current results of the design process.
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.
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.
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.
Sustainable Internet Architecture PROJECT DESCRIPTION
Kuzmanovic, Aleksandar
Sustainable Internet Architecture PROJECT DESCRIPTION 1 Introduction The Internet currently plays of challenges. Numerous research studies on a new Internet architecture (e.g., [16, 37, 48, 54, 55]) have on both the new Internet architecture itself and the underlying problems that motivate it. We look
Syllabus PHYS 441 Course Description
Lathrop, Daniel P.
Syllabus PHYS 441 Course Description A survey of concepts in particle and nuclear physics. We of the nucleus and the foundation of modern nuclear and particle physics. 2. Nuclear Phenomenology: Properties will learn about particles and forces that make up this universe, modern theories about these forces
ARCHITECTURE PROGRAMS AND COURSE DESCRIPTIONS
Kamat, Vineet R.
20092010 ARCHITECTURE PROGRAMS AND COURSE DESCRIPTIONS UNIVERSITY OF MICHIGAN #12;© 2008, degree options, and courses for the UM architecture program. This document is available for download from the Taubman College website at http://www.TaubmanCollege. umich.edu/architecture/bulletin/. If you
MICHIGAN TECHNOLOGICAL UNIVERSITY CLASSIFICATION DESCRIPTION
MICHIGAN TECHNOLOGICAL UNIVERSITY CLASSIFICATION DESCRIPTION Job Title: STAFF ASSISTANT (N6) Department: J. ROBERT VAN PELT LIBRARY Hourly Rate: MINIMUM $12.65 MAXIMUM $16.20 Supervisor: STRATEGIC INITIATIVES LIBRARIAN SUMMARY: This position participates in a variety of digital library and service
THE UNIVERSITY OF CLASSIFICATION DESCRIPTION
Portman, Douglas
1 THE UNIVERSITY OF ROCHESTER CLASSIFICATION DESCRIPTION TITLE: Web Specialist and Analyst DATE: 01 Advancement Service and provide assistance in the development and management of web-based assets, direct solicitations support webpages for print and e-mail marketing support, web development, Share
RF test bench automation Description
Dobigeon, Nicolas
RF test bench automation Description: Callisto would like to implement automated RF test bench. Three RF test benches have to be studied and automated: LNA noise temperature test bench LNA gain phase of the test benches and an implementation of the automation phase. Tasks: Noise temperature
Asymptotic description of radially localized short wavelength eigenmodes in a tokamak
Asymptotic description of radially localized short wavelength eigenmodes in a tokamak G. V-driven instabilities in a tokamak. It is shown that eigenmodes of the ballooning type are generated by toroidally
Kintzley, Keith Russell
1995-01-01T23:59:59.000Z
utilizing multiple description scalar quantizers (MDSQ) for correlated Rayleigh fading channels. In this thesis, we construct two different types of MDSQ-based systems: a fixed length coding system and a variable length coding system. Both employ...
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.
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)41clothThe Bonneville Power Administration wouldDecember 2014 NationalDepartmentConvergence using BerkeleyGWDesaturase
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)41clothThe Bonneville Power Administration wouldDecember 2014 NationalDepartmentConvergence using
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.
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.
LOCH: Open Access Facilitator Job Description (DRAFT)
McMahon, Jacqueline
2015-03-23T23:59:59.000Z
DRAFT Job Description for an Open Access Facilitator job in the University of Edinburgh's College of Humanities and Social Sciences. This draft job description is being made available as part of the Jisc-funded LOCH Project....
OPERATING INSTRUCTIONS AND SYSTEM DESCRIPTION FOR THE
OPERATING INSTRUCTIONS AND SYSTEM DESCRIPTION FOR THE ACl-01 AUTOMATIC APPARATUS FOR CHLORINATING. The system is batteries operated and has an auto power off function. The ACl-01 system is housed in a small................................................................................................................. 2 2. General System Description
University of Memphis University Libraries -Position Description
Dasgupta, Dipankar
the needs of library users and library personnel. The Emerging Technologies Librarian is a memberUniversity of Memphis University Libraries - Position Description Description Updated: November 2012 1 I. DEPARTMENT: University Libraries Library Information Systems II. POSITION: Emerging
Appendix 14-D Camp/Clinic Description
Swaddle, John
Appendix 14-D Camp/Clinic Description Revised August 2010 SPORT CAMP/CLINIC DESCRIPTION FORM) ________________________________________________________ Sport: __________ ___________ Name of Camp/Clinic: _______________________________ Camp Director ____ Double Classroom ____ Plumeri Park ____ Other _____________________ #12;Appendix 14-D Camp/Clinic
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.
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.
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.
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...
SEDIMENT DESCRIPTIONS R/V POLAR DUKE
#12;#12;SEDIMENT DESCRIPTIONS for R/V POLAR DUKE CRUISE II, 1992 to the ANTARCTIC PENINSULA #12;#12;DESCRIPTIONS OF SEDIMENT RECOVERED BY THE R/V POLAR DUKE, UNITED STATES ANTARCTIC PROGRAM CRUISE II, 1992 TO THE ANTARCTIC PENINSULA Edited by Thomas R. Janecek Sediment Descriptions* Matthew Curren (Antarctic Marine
SEDIMENT DESCRIPTIONS R/V POLAR DUKE
#12;#12;SEDIMENT DESCRIPTIONS R/V POLAR DUKE CRUISES II & VII, 1990 #12;#12;DESCRIPTIONS OF SEDIMENT RECOVERED BY THE R/V POLAR DUKE, CRUISES II & VII UNITED STATES ANTARCTIC PROGRAM 1990 Edited by Steven A. Hovan and Thomas R. Janecek Sediment Descriptions Xinlan Liu Technical Assistant Carl Painter
GENERATING TEXT DESCRIPTIONS FOR GEOGRAPHICALLY DISTRIBUTED SENSORS
Molina, Martín
GENERATING TEXT DESCRIPTIONS FOR GEOGRAPHICALLY DISTRIBUTED SENSORS Martin Molina and Javier generation of geographic descriptions in natural language for geographically distributed sensors. We describe and the algorithm that we designed to generate the geographic descriptions for sensors. Besides GIS data files, our
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.
SNF AGING SYSTEM DESCRIPTION DOCUMENT
L.L. Swanson
2005-04-06T23:59:59.000Z
The purpose of this system description document (SDD) is to establish requirements that drive the design of the spent nuclear fuel (SNF) aging system and associated bases, which will allow the design effort to proceed. This SDD will be revised at strategic points as the design matures. This SDD identifies the requirements and describes the system design, as it currently exists, with emphasis on attributes of the design provided to meet the requirements. This SDD is an engineering tool for design control; accordingly, the primary audience and users are design engineers. This SDD is part of an iterative design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. The SDD follows the design with regard to the description of the system. The description provided in the SDD reflects the current results of the design process. Throughout this SDD, the term aging cask applies to vertical site-specific casks and to horizontal aging modules. The term overpack is a vertical site-specific cask that contains a dual-purpose canister (DPC) or a disposable canister. Functional and operational requirements applicable to this system were obtained from ''Project Functional and Operational Requirements'' (F&OR) (Curry 2004 [DIRS 170557]). Other requirements that support the design process were taken from documents such as ''Project Design Criteria Document'' (PDC) (BSC 2004 [DES 171599]), ''Site Fire Hazards Analyses'' (BSC 2005 [DIRS 172174]), and ''Nuclear Safety Design Bases for License Application'' (BSC 2005 [DIRS 171512]). The documents address requirements in the ''Project Requirements Document'' (PRD) (Canori and Leitner 2003 [DIRS 166275]). This SDD includes several appendices. Appendix A is a Glossary; Appendix B is a list of key system charts, diagrams, drawings, lists and additional supporting information; and Appendix C is a list of procedures that will be used to operate the system.
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.
Descriptive Model of Generic WAMS
Hauer, John F.; DeSteese, John G.
2007-06-01T23:59:59.000Z
The Department of Energy’s (DOE) Transmission Reliability Program is supporting the research, deployment, and demonstration of various wide area measurement system (WAMS) technologies to enhance the reliability of the Nation’s electrical power grid. Pacific Northwest National Laboratory (PNNL) was tasked by the DOE National SCADA Test Bed Program to conduct a study of WAMS security. This report represents achievement of the milestone to develop a generic WAMS model description that will provide a basis for the security analysis planned in the next phase of this study.
AHTR Refueling Systems and Process Description
Varma, Venugopal Koikal [ORNL; Holcomb, David Eugene [ORNL; Bradley, Eric Craig [ORNL; Zaharia, Nathaniel M [ORNL; Cooper, Eliott J [ORNL
2012-07-01T23:59:59.000Z
The Advanced High-Temperature Reactor (AHTR) is a design concept for a central station-type [1500 MW(e)] Fluoride salt-cooled High-temperature Reactor (FHR) that is currently undergoing development by Oak Ridge National Laboratory for the US. Department of Energy, Office of Nuclear Energy's Advanced Reactor Concepts program. FHRs, by definition, feature low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. The overall goal of the AHTR development program is to demonstrate the technical feasibility of FHRs as low-cost, large-size power producers while maintaining full passive safety. The AHTR is approaching a preconceptual level of maturity. An initial integrated layout of its major systems, structures, and components (SSCs), and an initial, high-level sequence of operations necessary for constructing and operating the plant is nearing completion. An overview of the current status of the AHTR concept has been recently published and a report providing a more detailed overview of the AHTR structures and mechanical systems is currently in preparation. This report documents the refueling components and processes envisioned at this early development phase. The report is limited to the refueling aspects of the AHTR and does not include overall reactor or power plant design information. The report, however, does include a description of the materials envisioned for the various components and the instrumentation necessary to control the refueling process. The report begins with an overview of the refueling strategy. Next a mechanical description of the AHTR fuel assemblies and core is provided. The reactor vessel upper assemblies are then described. Following this the refueling path structures and the refueling mechanisms and components are described. The sequence of operations necessary to fuel and defuel the reactor is then discussed. The report concludes with a discussion of the levels of maturity of the various SSCs to provide guidance for future technology developments. The conceptual design information presented in this report is very preliminary in nature. Significant uncertainty remains about several aspects of the process and even the radiation and mechanical performance of plate-type coated-particle fuel.
AHTR Refueling Systems and Process Description
Varma, V.K.; Holcomb, D.E.; Bradley, E.C.; Zaharia, N.M.; Cooper, E.J.
2012-07-15T23:59:59.000Z
The Advanced High-Temperature Reactor (AHTR) is a design concept for a central station-type [1500 MW(e)] Fluoride salt–cooled High-temperature Reactor (FHR) that is currently undergoing development by Oak Ridge National Laboratory for the US. Department of Energy, Office of Nuclear Energy’s Advanced Reactor Concepts program. FHRs, by definition, feature low-pressure liquid fluoride salt cooling, coated-particle fuel, a high-temperature power cycle, and fully passive decay heat rejection. The overall goal of the AHTR development program is to demonstrate the technical feasibility of FHRs as low-cost, large-size power producers while maintaining full passive safety. The AHTR is approaching a preconceptual level of maturity. An initial integrated layout of its major systems, structures, and components (SSCs), and an initial, high-level sequence of operations necessary for constructing and operating the plant is nearing completion. An overview of the current status of the AHTR concept has been recently published [1], and a report providing a more detailed overview of the AHTR structures and mechanical systems is currently in preparation. This report documents the refueling components and processes envisioned at this early development phase. The report is limited to the refueling aspects of the AHTR and does not include overall reactor or power plant design information. The report, however, does include a description of the materials envisioned for the various components and the instrumentation necessary to control the refueling process. The report begins with an overview of the refueling strategy. Next a mechanical description of the AHTR fuel assemblies and core is provided. The reactor vessel upper assemblies are then described. Following this the refueling path structures and the refueling mechanisms and components are described. The sequence of operations necessary to fuel and defuel the reactor is then discussed. The report concludes with a discussion of the levels of maturity of the various SSCs to provide guidance for future technology developments. The conceptual design information presented in this report is very preliminary in nature. Significant uncertainty remains about several aspects of the process and even the radiation and mechanical performance of plate-type coated-particle fuel.
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.
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
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...
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.
The tropical double description method
Allamigeon, Xavier; Goubault, Eric
2010-01-01T23:59:59.000Z
We develop a tropical analogue of the classical double description method allowing one to compute an internal representation (in terms of vertices) of a polyhedron defined externally (by inequalities). The heart of the tropical algorithm is a characterization of the extreme points of a polyhedron in terms of a system of constraints which define it. We show that checking the extremality of a point reduces to checking whether there is only one minimal strongly connected component in an hypergraph. The latter problem can be solved in almost linear time, which allows us to eliminate quickly redundant generators. We report extensive tests (including benchmarks from an application to static analysis) showing that the method outperforms experimentally the previous ones by orders of magnitude. The present tools also lead to worst case bounds which improve the ones provided by previous methods.
Continuous description of fluctuating eccentricities
Jean-Paul Blaizot; Wojciech Broniowski; Jean-Yves Ollitrault
2014-05-14T23:59:59.000Z
We consider the initial energy density in the transverse plane of a high energy nucleus-nucleus collision as a random field $\\rho(\\x)$, whose probability distribution $P[\\rho]$, the only ingredient of the present description, encodes all possible sources of fluctuations. We argue that it is a local Gaussian, with a short-range 2-point function, and that the fluctuations relevant for the calculation of the eccentricities that drive the anisotropic flow have small relative amplitudes. In fact, this 2-point function, together with the average density, contains all the information needed to calculate the eccentricities and their variances, and we derive general model independent expressions for these quantities. The short wavelength fluctuations are shown to play no role in these calculations, except for a renormalization of the short range part of the 2-point function. As an illustration, we compare to a commonly used model of independent sources, and recover the known results of this model.
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.
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.
MICHIGAN TECHNOLOGICAL UNIVERSITY CLASSIFICATION DESCRIPTION
Endres. William J.
good judgment regarding set policies and procedures. Provide excellent customer service to a wide and external customers. Sell tickets and process cash receipts for athletic and cultural events using a web, compose, and type correspondence utilizing word processing software. Coordinate the daily operation
Machinist Pipeline/Apprentice Program Program Description
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Machinist PipelineApprentice Program Program Description The Machinist Pipeline Program was created by the Prototype Fabrication Division to fill a critical need for skilled...
Content of system design descriptions
NONE
1998-10-01T23:59:59.000Z
A System Design Description (SDD) describes the requirements and features of a system. This standard provides guidance on the expected technical content of SDDs. The need for such a standard was recognized during efforts to develop SDDs for safety systems at DOE Hazard Category 2 nonreactor nuclear facilities. Existing guidance related to the corresponding documents in other industries is generally not suitable to meet the needs of DOE nuclear facilities. Across the DOE complex, different contractors have guidance documents, but they vary widely from site to site. While such guidance documents are valuable, no single guidance document has all the attributes that DOE considers important, including a reasonable degree of consistency or standardization. This standard is a consolidation of the best of the existing guidance. This standard has been developed with a technical content and level of detail intended to be most applicable to safety systems at DOE Hazard Category 2 nonreactor nuclear facilities. Notwithstanding that primary intent, this standard is recommended for other systems at such facilities, especially those that are important to achieving the programmatic mission of the facility. In addition, application of this standard should be considered for systems at other facilities, including non-nuclear facilities, on the basis that SDDs may be beneficial and cost-effective.
required. 367 Renewable Energy Systems 368 Environmental Law, Toxic Substances, and Conservation 400 2013 Page 12 Course Description: Types, origins, settings, and structure of wetlands. Physical Fieldcraft & Field Methods for Environ Researchers 411 Energy Resources 441 Environmental Ethics 449
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...
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.
Multiple description coding by successive quantization
Linder, TamĂˇs
is with the Department of Electrical and Computer Engi- neering, University of Toronto, Toronto, Ontario M5S 3G4, Canada for transmission over a diversity communication system with several channels. In this technique, the source-description quantization problem, source samples are quantized into two descriptions with rates R1 and R2, respectively
University of Memphis University Libraries Position Description
Dasgupta, Dipankar
. CLASSIFICATION: Faculty IV. NAME OF INCUMBENT: Vacant V. POSITION No.: 2260 VI. JOB PURPOSE: This position/her responsibilities focus on removing barriers to information that are created when the library user needs informationUniversity of Memphis University Libraries Position Description Description last updated: August
University of Memphis University Libraries -Position Description
Dasgupta, Dipankar
1 I. DEPARTMENT: University Libraries II. POSITION: ILS Librarian III. CLASSIFICATION: Faculty IV strategies to maximize the effective use of the various components of the ILMS to meet the needs of libraryUniversity of Memphis University Libraries - Position Description Description Updated: August 2010
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.
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.
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.
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.
Detaled description of spontaneous emission
Marat Guryev
2012-11-29T23:59:59.000Z
The wave side of wave-photon duality, describing light as an electromagnetic field (EMF), is used in this article. EMF of spontaneous light emission (SE) of laser excited atom is calculated from first principles for the first time. This calculation is done using simple method of atomic quantum electrodynamics. EMF of SE is calculated also for three types of polyatomic light sources excited by laser. It is shown that light radiated by such sources can be coherent, which explains recent experiments on SE of laser excited atoms. Small sources of SE can be superradiant, which also conforms to experiment. Thus SE is shown not to be a random event itself. Random properties of natural light are simply explained as a result of thermal excitation randomness without additional hypotheses. EMF of SE is described by simple complex functions but not real ones.
Dynamic Scene Description System ---ODYS Jacek Malec
Malec, Jacek
ODYS (Opis DYnamicznej Sceny robota), is able to analyse descriptions of consecutive frames for analysing and describing dynamic scene of a robot is presented. The system, called ODYS (Opis DYnamicznej
Job Position Description Job Title: Office Assistant
Moore, Paul A.
Job Position Description Job Title: Office Assistant A. Main purpose of the job: To assist of Campus Operations. B. Primary responsibilities or key duties of the job (tasks performed regularly
Job Position Description Job Title: Locksmith Assistant
Moore, Paul A.
Job Position Description Job Title: Locksmith Assistant A. Main purpose of the job: Assist responsibilities or key duties of the job (tasks performed regularly): 1. Perform lock changes in all facilities
Job Position Description Job Title: Custodial Worker
Moore, Paul A.
Job Position Description Job Title: Custodial Worker A. Main purpose of the job: Clean academic buildings and/or residence halls. B. Primary responsibilities or key duties of the job (tasks
Embedding Hardware Description Languages in Proof Systems
Goossens, Kees G W
The aim of this thesis is to investigate the integration of hardware description lamguaages (HDLs) and automated proof systems. Simulation of circuit designs written in an HDL is an important method of testing their ...
Multimedia Developer, TBD Job Description Questionnaire (JDQ)
Barrash, Warren
Multimedia Developer, TBD Job Description Questionnaire (JDQ) Professional Staff Instructions What Below to Certify Approval or Disapproval: Approval Disapproval ( ) ( ) TBD, Multimedia Developer Position Title: Multimedia Developer Employee Name: TBD Phone: Supervisor Name & Title: TBD, Production
JOB DESCRIPTION Requisition ID 4206BR
general office and administrative policies. · May supervise lower level staff members. · Schedules in accordance with established procedures. · Performs research and/or statistical analyses and assistsJOB DESCRIPTION Requisition ID 4206BR ASU Job Title Administrative Secretary Job Title
Bell Nursery USA, LLC Internship Position Description
Bell Nursery USA, LLC Internship Position Description Internship Program Goal as a grower. Grower/Internship position : It is our goal at Bell to provide a rewarding and educational experience to the student/intern. The internship position
Broader source: Energy.gov [DOE]
The CHP R&D project portfolio includes advanced reciprocating engine systems (ARES), packaged CHP systems, high-value applications, fuel-flexible CHP, and demonstrations of these technologies. Project fact sheets and short project descriptions are provided below:
Creation of Computer Animation from Story Descriptions
Kahn, Kenneth Michael
1979-08-01T23:59:59.000Z
This report describes a computer system that creates simple computer animation in response to high-level, vague, and incomplete descriptions of films. It makes its films by collecting and evaluating suggestions from ...
University of Memphis University Libraries Position Description
Dasgupta, Dipankar
III. CLASSIFICATION: LIBRARY ASSISTANT III IV. NAME OF INCUMBENT: Vacant V. POSITION NO.: 1259 VI. JOBUniversity of Memphis University Libraries Position Description 1 I. DEPARTMENT: University Libraries: Collection Management, ILL & Document Delivery II. POSITION: Interlibrary Loan Library Assistant
Alternative descriptions and bipartite compound quantum systems
G. Scolarici; L. Solombrino
2008-11-10T23:59:59.000Z
We analyze some features of alternative Hermitian and quasi-Hermitian quantum descriptions of simple and bipartite compound systems. We show that alternative descriptions of two interacting subsystems are possible if and only if the metric operator of the compound system can be obtained as tensor product of positive operators on component spaces. Some examples also show that such property could be strictly connected with symmetry properties of the non-Hermitian Hamiltonian.
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.
The shape dynamics description of gravity
Tim Koslowski
2015-01-13T23:59:59.000Z
Classical gravity can be described as a relational dynamical system without ever appealing to spacetime or its geometry. This description is the so-called shape dynamics description of gravity. The existence of relational first principles from which the shape dynamics description of gravity can be derived is a motivation to consider shape dynamics (rather than GR) as the fundamental description of gravity. Adopting this point of view leads to the question: What is the role of spacetime in the shape dynamics description of gravity? This question contains many aspects: Compatibility of shape dynamics with the description of gravity in terms of spacetime geometry, the role of local Minkowski space, universality of spacetime geometry and the nature of quantum particles, which can no longer be assumed to be irreducible representations of the Poincare group. In this contribution I derive effective spacetime structures by considering how matter fluctuations evolve along with shape dynamics. This evolution reveals an "experienced spacetime geometry." This leads (in an idealized approximation) to local Minkowski space and causal relations. The small scale structure of the emergent geometric picture depends on the specific probes used to experience spacetime, which limits the applicability of effective spacetime to describe shape dynamics. I conclude with discussing the nature of quantum fluctuations (particles) in shape dynamics and how local Minkowski spacetime emerges from the evolution of quantum particles.
Lorentz Multiplet Structure of Baryon Spectra and Relativistic Description
Kirchbach, M
1997-01-01T23:59:59.000Z
The pole positions of the various baryon resonances are known to reveal well-pronounced clustering, so-called Hoehler clusters. For nonstrange baryons the Hoehler clusters are shown to be identical to Lorentz multiplets of the type (j,j)*[(1/2,0)+(0,1/2)] with j being a half-integer. For the Lambda hyperons below 1800 MeV these clusters are shown to be of the type [(1,0)+ (0,1)]*[(1/2,0)+(0,1/2)] while above 1800 MeV they are parity duplicated (J,0)+(0,J) (Weinberg-Ahluwalia) states. Therefore, for Lambda hyperons the restoration of chiral symmetry takes place above 1800 MeV. Finally, it is demonstrated that the description of spin-3/2 particles in terms of a 2nd rank antisymmetric Lorentz tensor with Dirac spinor components does not contain any off-shell parameters and avoids the main difficulties of the Rarita-Schwinger description based upon a 4-vector with Dirac spinor components.
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.
SEDIMENT DESCRIPTIONS R/V NATHANIEL B. PALMER
SEDIMENT DESCRIPTIONS for R/V NATHANIEL B. PALMER Cruise 1, 1996 #12;DESCRIPTIONS OF SEDIMENT. Janecek and Steven B. Petrushak Sediment Descriptions Florida State University Matthew G. Curren Antarctic...............................................................................................12 SEDIMENT CLASSIFICATION
SEDIMENT DESCRIPTIONS R/V NATHANIEL B. PALMER
SEDIMENT DESCRIPTIONS for R/V NATHANIEL B. PALMER Cruise 1A, 2003 #12;DESCRIPTIONS OF SEDIMENT. Petrushak Sediment Descriptions Florida State University Matthew G. Curren Modified by Steven Petrushak.................................................................................................8 SEDIMENT CLASSIFICATION
Stability of the holographic description of the Universe
Peng Huang; Yong-chang Huang
2013-04-01T23:59:59.000Z
We investigate the stability of the holographic description of the universe. By treating the perturbation globally, we discover that this description is stable, which is support for the holographic description of the universe.
Intro Probability Rabbits Description Predictions Ontology of Earthquake Probability: Metaphor
Stark, Philip B.
Intro Probability Rabbits Description Predictions Ontology of Earthquake Probability: Metaphor be abandoned in favor of common sense. #12;Intro Probability Rabbits Description Predictions Earthquake not random. Wm. ShakesEarth #12;Intro Probability Rabbits Description Predictions Earthquake Poker
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.
Physics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String
California at Santa Cruz, University of
, Vibrations and Waves (W.W. Norton and Company, New York, 1971). First, we compute the kinetic energyPhysics 5B Winter 2009 Rate of Energy Transfer by Sinusoidal Waves on a String Consider the kinetic energy and the potential energy of this string segment due to the passage of a traveling wave
Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1
Durrer, Ruth
Kalb-Ramond axion production in anisotropic string cosmologies Ruth Durrer1 and Mairi Sakellariadou the energy spectra for massless Kalb-Ramond axions in four-dimensional anisotropic string cosmological models). In contrast, the axion energy spectra were found to be diverging at large scales, red spectra, leading to very
RIS-M-2256 INPUT DESCRIPTION FOR THE THREE-DIMENSIONAL
RISŘ-M-2256 INPUT DESCRIPTION FOR THE THREE-DIMENSIONAL PWR TRANSIENT CODE ANTI E. Falcon Nielsen A calculations for the PWR core. It combines a nodal theory neutron kinetics calculation with transient sub, PWR TYPE REACTORS, REACTOR KINETICS, THREE-DIMENSIONAL CALCULATIONS, TRANSIENTS. UDC 621.039.514 : 621
String-theoretic breakdown of effective field theory near black hole horizons
Dodelson, Matthew
2015-01-01T23:59:59.000Z
We investigate the validity of the equivalence principle near horizons in string theory, analyzing the breakdown of effective field theory caused by longitudinal string spreading effects. An experiment is set up where a detector is thrown into a black hole a long time after an early infalling string. Light cone gauge calculations, taken at face value, indicate a detectable level of root-mean-square longitudinal spreading of the initial string as measured by the late infaller. This results from the large relative boost between the string and detector in the near horizon region, which develops automatically despite their modest initial energies outside the black hole and the weak curvature in the geometry. We subject this scenario to basic consistency checks, using these to obtain a relatively conservative criterion for its detectability. In a companion paper, we exhibit longitudinal nonlocality in well-defined gauge-invariant S-matrix calculations, obtaining results consistent with the predicted spreading albe...
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Department Name: Position Number WEIGHTED JOB QUESTIONNAIRE (WJQ) CUSTOM PARTI: JOB DESCRIPTION 1. POSITION IDENTIFICATION Department
SEDIMENT DESCRIPTIONS R/V NATHANIEL B. PALMER
SEDIMENT DESCRIPTIONS for R/V NATHANIEL B. PALMER Cruise 7, 1995 #12;DESCRIPTIONS OF SEDIMENT-Slide Analysis.........................................................................11 SEDIMENT CLASSIFICATION...................................................................11 Pelagic sediment..............................................................................12
Gauge/String-Gravity Duality and Froissart Bound
Kyungsik Kang
2004-10-16T23:59:59.000Z
The gauge/string-gravity duality correspondence opened renewed hope and possibility to address some of the fundamental and non-perturbative QCD problems in particle physics, such as hadron spectrum and Regge behavior of the scattering amplitude at high energies. One of the most fundamental and long-standing problem is the high energy behavior of total cross-sections. According to a series of exhaustive tests by the COMPETE group, (1). total cross-sections have a universal Heisenberg behavior in energy corresponding to the maximal energy behavior allowed by the Froissart bound, i.e., $A + B ln^2 (s/s_0)$ with $B \\sim 0.32 mb$ and $s_0 \\sim 34.41 GeV^2$ for all reactions, and (2). the factorization relation among $\\sigma_{pp, even}, \\sigma_{\\gamma p}, and \\sigma_{\\gamma \\gamma}$ is well satisfied by experiments. I discuss the recent interesting application of the gauge/string-gravity duality of $AdS/CFT$ correspondence with a deformed background metric so as to break the conformal symmetry that can lead to the Heisenberg behavior of rising total cross-sections, and present some preliminary results on the high energy QCD from Planckian scattering in $AdS$ and black-hole production.
Stable Non-Supersymmetric Throats in String Theory
Kachru, Shamit; Simic, Dusan; /Stanford U., ITP /SLAC /Santa Barbara, KITP; Trivedi, Sandip P.; /Tata Inst. /Stanford U., ITP /SLAC
2011-06-28T23:59:59.000Z
We construct a large class of non-supersymmetric AdS-like throat geometries in string theory by taking non-supersymmetric orbifolds of supersymmetric backgrounds. The scale of SUSY breaking is the AdS radius, and the dual field theory has explicitly broken supersymmetry. The large hierarchy of energy scales in these geometries is stable. We establish this by showing that the dual gauge theories do not have any relevant operators which are singlets under the global symmetries. When the geometries are embedded in a compact internal space, a large enough discrete subgroup of the global symmetries can still survive to prevent any singlet relevant operators from arising. We illustrate this by embedding one case in a non-supersymmetric orbifold of a Calabi-Yau manifold. These examples can serve as a starting point for obtaining Randall-Sundrum models in string theory, and more generally for constructing composite Higgs or technicolor-like models where strongly coupled dynamics leads to the breaking of electro-weak symmetry. Towards the end of the paper, we briefly discuss how bulk gauge fields can be incorporated by introducing D7-branes in the bulk, and also show how the strongly coupled dynamics can lead to an emergent weakly coupled gauge theory in the IR with matter fields including scalars.
A keV String Axion from High Scale Supersymmetry
Brian Henning; John Kehayias; Hitoshi Murayama; David Pinner; Tsutomu T. Yanagida
2015-03-20T23:59:59.000Z
Various theoretical and experimental considerations motivate models with high scale supersymmetry breaking. While such models may be difficult to test in colliders, we propose looking for signatures at much lower energies. We show that a keV line in the X-ray spectrum of galaxy clusters (such as the recently disputed 3.5 keV observation) can have its origin in a universal string axion coupled to a hidden supersymmetry breaking sector. A linear combination of the string axion and an additional axion in the hidden sector remains light, obtaining a mass of order 10 keV through supersymmetry breaking dynamics. In order to explain the X-ray line, the scale of supersymmetry breaking must be about $10^{11-12}$ GeV. This motivates high scale supersymmetry as in pure gravity mediation or minimal split supersymmetry and is consistent with all current limits. Since the axion mass is controlled by a dynamical mass scale, this mass can be much higher during inflation, avoiding isocurvature (and domain wall) problems associated with high scale inflation. In an appendix we present a mechanism for dilaton stabilization that additionally leads to $\\mathcal{O}(1)$ modifications of the gaugino mass from anomaly mediation.
Is the Universal String Axion the QCD Axion
Gaillard, Mary K.; Kain, Ben
2005-10-14T23:59:59.000Z
We consider the class of effective supergravity theories from the weakly coupled heterotic string in which local supersymmetry is broken by gaugino condensation in a hidden sector, with dilaton stabilization achieved through corrections to the classical dilaton Kahler potential. If there is a single hidden condensing (simple) gauge group, the axion is massless (up to contributions from higher dimension operators) above the QCD condensation scale. We show how the standard relation between the axion mass and its Planck scale coupling constant is modified in this class of models due to a contribution to the axion-gluon coupling that appears below the scale of supersymmetry breaking when gluinos are integrated out. In particular there is a point of enhanced symmetry in parameter space where the axion mass is suppressed. We revisit the question of the universal axion as the Peccei-Quinn axion in the light of these results, and find that the strong CP problem is avoided in most compactifications of the weakly coupled heterotic string.
STUDY TYPES What is a "Study Type"?
Dorf, Martin E.
#12;STUDY TYPES What is a "Study Type"? A Study Type is a defined business process. Study Types work together to streamline workflow, track data & keep users informed. There are 2 Study Types in eCOMS: COMS and IACUC. The COMS Study: The COMS Study is an online form that a Principal Investigator fills
Hartman, C W; Reisman, D B; McLean, H S; Thomas, J
2007-05-30T23:59:59.000Z
A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed region where fusion energy is produced and, on emergence from the fusion region, the CT undergoes controlled expansion in an exit cone where an alternating poloidal field opens the flux surfaces to directly recover the CT magnetic energy as current which is returned to the formation gun. The CT String Reactor (CTSTR) reactor satisfies all the necessary MHD stability requirements and is based on extrapolation of experimentally achieved formation, stability, and plasma confinement. It is supported by extensive 2D, MHD calculations. CTSTR employs minimal external fields supplied by normal conductors, and can produce high fusion power density with uniform wall loading. The geometric simplicity of CTSTR acts to minimize initial and maintenance costs, including periodic replacement of the reactor first wall.
Description of the RDCDS Meteorological Component
Pekour, Mikhail S.; Berg, Larry K.
2007-10-01T23:59:59.000Z
This report provides a detailed description of the Rapidly Deployable Chemical Defense System (RDCDS) Meteorological Component. The Meteorological Component includes four surface meteorological stations, miniSODAR, laptop computers, and communications equipment. This report describes the equipment that is used, explains the operation of the network, and gives instructions for setting up the Component and replacing defective parts. A detailed description of operation and use of the individual sensors, including the data loggers is not covered in the current document, and the interested reader should refer to the manufacturer’s documentation.
Lawson Job Description Acknowledgment Instructions Log In to Lawson
Gleeson, Joseph G.
Lawson Job Description Acknowledgment Instructions · Log In to Lawson o Lawson Web Address: - https. Updated 3/15/10 Page 1 of 6 #12;Lawson Job Description Acknowledgment Instructions Click "My Job Description" · Click "My Job Description" from the Employee Central section of your home page o "My Job
Better Buildings Neighborhood Program Business Models Guide: Program Administrator Description
Broader source: Energy.gov [DOE]
Better Buildings Neighborhood Program Business Models Guide: Program Administrator Business Models, Program Administrator Description.
CASK/MSC/WP PREPARATION SYSTEM DESCRIPTION DOCUMENT
S. Drummond
2005-04-12T23:59:59.000Z
The purpose of this system description document (SDD) is to establish requirements that drive the design of the Cask/MSC/WP preparation system and their bases to allow the design effort to proceed to license application. This SDD is a living document that will be revised at strategic points as the design matures over time. This SDD identifies the requirements and describes the system design, as they exist at this time, with emphasis on those attributes of the design provided to meet the requirements. This SDD has been developed to be an engineering tool for design control. Accordingly, the primary audience and users are design engineers. This type of SDD both leads and trails the design process. It leads the design process with regard to the flow down of upper tier requirements onto the system. Knowledge of these requirements is essential in performing the design process. This SDD trails the design with regard to the description of the system. The description provided in the SDD is a reflection of the results of the design process to date. This SDD addresses the ''Project Requirements Document'' (PRD) (Canori and Leitner 2003 [DIRS 166275]) requirements. Additional PRD requirements may be cited, as applicable, to drive the design of specific aspects of the system, with justifications provided in the basis. Functional and operational requirements applicable to this system are obtained from the ''Project Functional and Operational Requirements'' (F&OR) (Curry 2004 [DIRS 170557]) document. Other requirements to support the design process have been taken from higher-level requirements documents such as the ''Project Design Criteria Document'' (PDC) (BSC 2004 [DIRS 171599]) and the preclosure safety analyses.
Molotkov, S. N., E-mail: sergei.molotkov@gmail.com [Russian Federation, Academy of Cryptography (Russian Federation)
2012-12-15T23:59:59.000Z
Any key-generation session contains a finite number of quantum-state messages, and it is there-fore important to understand the fundamental restrictions imposed on the minimal length of a string required to obtain a secret key with a specified length. The entropy uncertainty relations for smooth min and max entropies considerably simplify and shorten the proof of security. A proof of security of quantum key distribution with phase-temporal encryption is presented. This protocol provides the maximum critical error compared to other protocols up to which secure key distribution is guaranteed. In addition, unlike other basic protocols (of the BB84 type), which are vulnerable with respect to an attack by 'blinding' of avalanche photodetectors, this protocol is stable with respect to such an attack and guarantees key security.
Non-perturbative Effects in AdS5 * S5 String Theory and d=4 SUSY Yang-Mills
Tom Banks; Michael B. Green
1998-06-10T23:59:59.000Z
We show that five-dimensional anti de-Sitter space remains a solution to low-energy type IIB supergravity when the leading higher-derivative corrections to the classical supergravity (which are non-perturbative in the string coupling) are included. Furthermore, at this order in the low energy expansion of the IIB theory the graviton two-point and three-point functions in $AdS_5 \\times S^5$ are shown not to be renormalized and a precise expression is obtained for the four-graviton and related S-matrix elements. By invoking Maldacena's conjectured connection between IIB superstring theory and supersymmetric Yang-Mills theory corresponding statements are obtained concerning correlation functions of the energy-momentum tensor and related operators in the large-N Yang-Mills theory. This leads to interesting non-perturbative statements and insights into the r\\^ole of instantons in the gauge theory.
CONSTRAINING THE STRING GAUGE FIELD BY GALAXY ROTATION CURVES AND PERIHELION PRECESSION OF PLANETS
Cheung, Yeuk-Kwan E.; Xu Feng, E-mail: cheung@nju.edu.cn [Department of Physics, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)
2013-09-01T23:59:59.000Z
We discuss a cosmological model in which the string gauge field coupled universally to matter gives rise to an extra centripetal force and will have observable signatures on cosmological and astronomical observations. Several tests are performed using data including galaxy rotation curves of 22 spiral galaxies of varied luminosities and sizes and perihelion precessions of planets in the solar system. The rotation curves of the same group of galaxies are independently fit using a dark matter model with the generalized Navarro-Frenk-White (NFW) profile and the string model. A remarkable fit of galaxy rotation curves is achieved using the one-parameter string model as compared to the three-parameter dark matter model with the NFW profile. The average {chi}{sup 2} value of the NFW fit is 9% better than that of the string model at a price of two more free parameters. Furthermore, from the string model, we can give a dynamical explanation for the phenomenological Tully-Fisher relation. We are able to derive a relation between field strength, galaxy size, and luminosity, which can be verified with data from the 22 galaxies. To further test the hypothesis of the universal existence of the string gauge field, we apply our string model to the solar system. Constraint on the magnitude of the string field in the solar system is deduced from the current ranges for any anomalous perihelion precession of planets allowed by the latest observations. The field distribution resembles a dipole field originating from the Sun. The string field strength deduced from the solar system observations is of a similar magnitude as the field strength needed to sustain the rotational speed of the Sun inside the Milky Way. This hypothesis can be tested further by future observations with higher precision.
The Ideal Transformer Description and Circuit Symbol
King, Roger
The Ideal Transformer Description and Circuit Symbol As with all the other circuit elements, there is a physical transformer commonly used in circuits whose behavior can be discussed in great detail. However, in many cases the practical transformer can be adequately approximated by the "ideal transformer," which
The Scottish Forestry Strategy Description of indicators
The Scottish Forestry Strategy Description of indicators Updated December 2011 1 #12;T h e S c o of wood energy plant (in megawatt thermal and electrical) Number of non-domestic, wood fuelled energy sector Forecast wood availability from the national forest estate Timber's contribution to Scottish Value
FACULTY OF ENGINEERING MODULE DESCRIPTION FORM
Mottram, Nigel
Office Jan 2003) #12;Level of Achievement Statement for a JBM Accredited Engineering Module Module CodeFACULTY OF ENGINEERING MODULE DESCRIPTION FORM CODE CL508/906 Site Investigation & Risk Assessment Module Registrar: Dr P Sentenac Taught To (Course): Civil Engineering Other Lecturers Involved: Credit
FACULTY OF ENGINEERING MODULE DESCRIPTION FORM
Mottram, Nigel
Level: NQF 3 Prerequisites: none Module Format and Delivery (hours): Lecture Tutorial Assignments Visits visualisation). Uncovering the role of science and mathematics in the design of structures using case studyFACULTY OF ENGINEERING MODULE DESCRIPTION FORM CL 112 Introduction to Civil Engineering Module Code
DESCRIPTION OF ACCIDENT MSU DRIVERS SIGNATURE
Dyer, Bill
of Commercial Policy Number) Motor vehicles that are owned, rented, leased, or loaned to Montana State's Name: MSU VEHICLE (VEHICLE #1) Issued Citation: YES NO Explain: Department: Phone: 994 - Vehicle Owner: Use of Vehicle: Vehicle: Make Model Year VIN: Plate Number: State: Description of Damage: Safety
University of Alberta GIGA Program Description and
Culberson, Joseph
University of Alberta GIGA Program Description and Operation by Joseph Culberson Technical Report TR 92--06 June 1992 DEPARTMENT OF COMPUTING SCIENCE The University of Alberta Edmonton, Alberta of Alberta, Edmonton, Alberta, Canada, T6G 2H1. email:joe@cs.ualberta.ca y This paper is available via ftp
Alberta Alzheimer Research Program III Description
Michelson, David G.
Alberta Alzheimer Research Program III Description The Alzheimer Society of Alberta and Northwest Territories (ASANT) and the Alberta Prion Research Institute (Prion Institute) present the Alberta Alzheimer Research Program (AARP) III. The AARP III allows qualified Alberta-based investigators to seek funding
Internship Position Description Title: Refugee Resettlement Intern
Nelson, Tim
Internship Position Description Title: Refugee Resettlement Intern Purpose The purpose of the World in the field of refugee resettlement. Possible Responsibilities Assist Case Workers with attending and transporting refugee clients to important appointments. Help newly arrived families with tasks such as paying
HOUSING RESOURCES Description of Boston Neighborhoods
HOUSING RESOURCES Boston Description of Boston Neighborhoods http://www.bu.edu/offcampus/tips-resources/bostons-neighborhoods/ Summer Housing Boston http://www.urbaninterns.com/journal/jobseekers/summer-housing-for-boston-interns/ https://www.northeastern.edu/conferences/intern/index.html http://housing.mit.edu/summer_guest/non_mit_summer_internship_housing
DESCRIPTION OF SELECTED WASTE MANAGEMENT PROBLEMS,
#12;DESCRIPTION OF SELECTED WASTE MANAGEMENT PROBLEMS, OPTIONS AND STRATEGIES Prepared for BC OF FIGURES Figure 1.1 Agricultural Waste Management Zones 2 Figure 4.1 Option Categories Discussed Fraser Valley was divided into twenty Agricultural Waste Management Zones; these zones are shown
C. PROJECT DESCRIPTION 1. List of Participants
Pasternack, Gregory B.
, 1989), yet there are excellent examples in such efforts as the Manhattan Project, NASA's Apollo MoonC. PROJECT DESCRIPTION 1. List of Participants Name Role* Institution/Org.** Expertise Previous Program, and the Human Genome Project (Fogg and LaBolle, 2006). The driving force behind each
AN ALGEBRAIC DESCRIPTION OF ITERATIVE DECODING SCHEMES
Soljanin, Emina
AN ALGEBRAIC DESCRIPTION OF ITERATIVE DECODING SCHEMES ELKE OFFER AND EMINA SOLJANIN Abstract University of Technology, D- 80290 Munich, Germany, elke@lnt.e-technik.tu-muenchen.de Mathematical Sciences Research Center, Bell Labs, Lucent Technologies, Murray Hill, NJ 07974, USA. emina@lucent.com 1 #12;2 E
Multi-Level Platform Descriptions Colin Atkinson
Kühne, Thomas
Multi-Level Platform Descriptions Colin Atkinson Software Engineering Group University of Mannheim The MDA approach to software development is based on the notion of automating the mapping of platform independent models into implementation-level platform specific models based on abstract models of platforms
Deriving Security Requirements from Crosscutting Threat Descriptions
Haley, Charles B.
Deriving Security Requirements from Crosscutting Threat Descriptions Charles B. Haley, Robin C representing threats as crosscutting concerns aids in determining the effect of security requirements on the functional requirements. Assets (objects that have value in a system) are first enumerated, and then threats
HOUSING RESOURCES Description of Boston Neighborhoods
HOUSING RESOURCES Boston Description of Boston Neighborhoods http://www.bu.edu/offcampus/tips-resources is open to those who are at least 21 years old, and affiliated with an educational or professional=96679 http://www.conservativejobs.com/Resources/DClife.cfm LinkedIn Network for Young Professionals
April, 2000 1 PART I: JOB DESCRIPTION
April, 2000 1 PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Department Name: SFU ____ Evaluating Supervisor __X__ #12;April, 2000 2 SIMON FRASER UNIVERSITY & C.U.P.E., Local 3338 WEIGHTED JOB and academic requirements. Manages Corporate Time calendar for Grad Chair. #12;April, 2000 3 Accesses student
COURSE DESCRIPTION Dept., Number CS 4352
Kreinovich, Vladik
Semester hours 45 hours + 21 lab hours Course Coordinator Luc Longpré Current Catalog Description of programming languages, parsing techniques, intermediate languages, optimization and code generation. Textbook definition \\& manipulation including one and two pass updates. 3. lex and yacc to generate a basic parser 4
University of Memphis University Libraries Position Description
Dasgupta, Dipankar
University of Memphis University Libraries Position Description I. DEPARTMENT: Preservation and Special Collections II. POSITION: ULDR Assistant III. CLASSIFICATION: Graduate Assistantship IV. NAME OF INCUMBENT: Vacant V. POSITION NO.: VI. JOB PURPOSE This position is a member of the team providing support
University of Memphis University Libraries Position Description
Dasgupta, Dipankar
University of Memphis University Libraries Position Description I. DEPARTMENT: Preservation and Special Collections II. POSITION: NAAPA Assistant III. CLASSIFICATION: Graduate Assistantship IV. NAME OF INCUMBENT: Open V. POSITION NO.: 16330 VI. JOB PURPOSE This position is a member of the team providing
University of Memphis University Libraries -Position Description
Dasgupta, Dipankar
Libraries Library Information Systems II. POSITION: ILS Librarian III. CLASSIFICATION: Faculty IV. NAME of the various components of the ILMS to meet the needs of library users and library personnel. The ILS LibrarianUniversity of Memphis University Libraries - Position Description I. DEPARTMENT: University
Team Description Paper Virtual Robot competition
Visser, Arnoud
UvA Rescue Team Description Paper Virtual Robot competition Rescue Simulation League RoboCup Iran- ject [7], although their participation for the Iran Open and Brazil 2014 is not yet con#12;rmed and not full 6D SLAM, because the 3D point-cloud consists of slices of a rotating 2D laser scanner. When
II. DEVICE DESCRIPTION AND GENERAL PHYSICS REQUIREMENTS
II. DEVICE DESCRIPTION AND GENERAL PHYSICS REQUIREMENTS b. H. NEILSON, Jr. (ORNL) ILA. INTRODUCTION To accomplish the dual goals set forth in the mis- sion statement - determination of burning plasma physics years. The pro cess has drawn extensively upon the world toka- mak physics data base as well
Educational Leadership Description of the Program
Ravikumar, B.
Educational Leadership Description of the Program The Administrative Services Credential programs of leadership in P-12 education institutions. All students are admitted starting in the fall of each academic to the Educational Leadership program area of concentration for the M.A. degree in Education. This course of study
C. Pajares; D. Sousa; R. A. Vázquez
2000-05-31T23:59:59.000Z
At high gluon or string densities, gluons' saturation or the strong interaction among strings, either forming colour ropes or giving rise to string's percolation, induces a strong suppression in the particle multiplicities produced at high energy. This suppression implies important modifications on cosmic ray shower development. In particular, it is shown that it affects the depth of maximum, the elongation rate, and the behaviour of the number of muons at energies around 10^{17}-10^{18} eV. The existing cosmic ray data point out in the same direction.
Power-law Behavior of High Energy String Scatterings in Compact Spaces
Jen-Chi Lee; Yi Yang
2007-09-28T23:59:59.000Z
We calculate high energy massive scattering amplitudes of closed bosonic string compactified on the torus. We obtain infinite linear relations among high energy scattering amplitudes. For some kinematic regimes, we discover that some linear relations break down and, simultaneously, the amplitudes enhance to power-law behavior due to the space-time T-duality symmetry in the compact direction. This result is consistent with the coexistence of the linear relations and the softer exponential fall-off behavior of high energy string scattering amplitudes as we pointed out prevously. It is also reminiscent of hard (power-law) string scatterings in warped spacetime proposed by Polchinski and Strassler.
Z2 electric strings and center vortices in SU(2) lattice gauge theory
M. I. Polikarpov; P. V. Buividovich
2008-01-01T23:59:59.000Z
We study the representations of SU(2) lattice gauge theory in terms of sums over the worldsheets of center vortices and Z2 electric strings, i.e. surfaces which open on the Wilson loop. It is shown that in contrast to center vortices the density of electric Z2 strings diverges in the continuum limit of the theory independently of the gauge fixing, however, their contribution to the Wilson loop yields physical string tension due to non-positivity of their statistical weight in the path integral, which is in turn related to the presence of Z2 topological monopoles in the theory.
Airy Equation for the Topological String Partition Function in a Scaling Limit
Alim, Murad; Zhou, Jie
2015-01-01T23:59:59.000Z
We use the polynomial formulation of the holomorphic anomaly equations governing perturbative topological string theory to derive the free energies in a scaling limit to all orders in perturbation theory for any Calabi-Yau threefold. The partition function in this limit satisfies an Airy differential equation in a rescaled topological string coupling. One of the two solutions of this equation gives the perturbative expansion and the other solution provides geometric hints of the non-perturbative structure of topological string theory. Both solutions can be expanded naturally around strong coupling.
Wave and quantum properties of peptide strings: defining a helix in spacetime
Razvan Tudor Radulescu
2009-04-25T23:59:59.000Z
Previous studies have described the concept of peptide strings in qualitative terms and illustrated it by applying its corrolaries in order to elucidate basic questions in oncology and rheumatology. The present investigation is the first to quantify these potential sub- and transcellular phenomena. Accordingly, the propagation of peptide strings is proposed here to occur by way of waves that in turn are subject to the energy equation established by Planck. As a result of these insights, widespread future applications can now be envisaged for peptide strings both in molecular medicine and quantum optics.
CP Violation and Dilaton Stabilization in Heterotic String Models
S. Khalil; O. Lebedev; S. Morris
2002-04-26T23:59:59.000Z
We study the possibility of spontaneous CP violation in string models with the dilaton field stabilized at a phenomenologically acceptable value. We consider three mechanisms to stabilize the dilaton: multiple gaugino condensates, a nonperturbative Kahler potential, and a superpotential based on S-duality, and analyze consequent CP phases in the soft SUSY breaking terms. Due to non-universality forced upon the theory by requiring a non-trivial CKM phase, the EDM problem becomes more severe. Even if there are no complex phases in the VEVs of the SUSY breaking fields, the electric dipole moments are overproduced by orders of magnitude. We also address the question of modular invariance of the physical CP phases.
CP Violation and Dilaton Stabilization in Heterotic String Models
Khalil, S; Morris, S
2002-01-01T23:59:59.000Z
We study the possibility of spontaneous CP violation in string models with the dilaton field stabilized at a phenomenologically acceptable value. We consider three mechanisms to stabilize the dilaton: multiple gaugino condensates, a nonperturbative Kahler potential, and a superpotential based on S-duality, and analyze consequent CP phases in the soft SUSY breaking terms. Due to non-universality forced upon the theory by requiring a non-trivial CKM phase, the EDM problem becomes more severe. Even if there are no complex phases in the VEVs of the SUSY breaking fields, the electric dipole moments are overproduced by orders of magnitude. We also address the question of modular invariance of the physical CP phases.
Size scaling of self gravitating polymers and strings
Shoichi Kawamoto; Toshihiro Matsuo
2015-08-04T23:59:59.000Z
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. We show phase diagrams in various dimensions that clarify how the size changes as the strengths of repulsive and gravitational forces vary.
Birth of the Universe from the Landscape of String Theory
Archil Kobakhidze; Laura Mersini-Houghton
2004-10-20T23:59:59.000Z
We show that a unique, most probable and stable solution for the wavefunction of the universe, with a very small cosmological constant $\\Lambda_1 \\simeq (\\frac{\\pi}{l_p N})^2$, can be predicted from the supersymmetric minisuperspace with $N$ vacua, of the landscape of string theory without reffering to the antropic principle. Due to the nearest neighbor tunneling in moduli space lattice, the $N$-fold degeneracy of vacua is lifted and a discrete spectrum of bound state levels over the whole minisuperspace emerges. $SUSY$ is spontaneously broken by these bound states, with discrete nonzero energy levels $\\Lambda_s \\simeq (\\frac{s \\pi}{l_p N})^2$, $s = 1,2,..$.
Anthropic reasoning in multiverse cosmology and string theory
Steven Weinstein
2006-06-08T23:59:59.000Z
Anthropic arguments in multiverse cosmology and string theory rely on the weak anthropic principle (WAP). We show that the principle, though ultimately a tautology, is nevertheless ambiguous. It can be reformulated in one of two unambiguous ways, which we refer to as WAP_1 and WAP_2. We show that WAP_2, the version most commonly used in anthropic reasoning, makes no physical predictions unless supplemented by a further assumption of "typicality", and we argue that this assumption is both misguided and unjustified. WAP_1, however, requires no such supplementation; it directly implies that any theory that assigns a non-zero probability to our universe predicts that we will observe our universe with probability one. We argue, therefore, that WAP_1 is preferable, and note that it has the benefit of avoiding the inductive overreach characteristic of much anthropic reasoning.
String compactification, QCD axion and axion-photon-photon coupling
Kang-Sin Choi; Ian-Woo Kim; Jihn E. Kim
2007-01-13T23:59:59.000Z
It is pointed out that there exist a few problems to be overcome toward an observable sub-eV QCD axion in superstring compactification. We give a general expression for the axion decay constant. For a large domain wall number $N_{DW}$, the axion decay constant can be substantially lowered from a generic value of a scalar singlet VEV. The Yukawa coupling structure in the recent $Z_{12-I}$ model is studied completely, including the needed nonrenormalizable terms toward realistic quark and lepton masses. In this model we find an approximate global symmetry and vacuum so that a QCD axion results but its decay constant is at the GUT scale. The axion-photon-photon coupling is calculated for a realistic vacuum satisfying the quark and lepton mass matrix conditions. It is the first time calculation of $c_{a\\gamma\\gamma}$ in realistic string compactifications: $c_{a\\gamma\\gamma}={5/3}-1.93\\simeq -0.26$.
System Description: H-PILoT (Version 1.9)
Ihlemann, Carsten
2010-01-01T23:59:59.000Z
This system description provides an overview of H-PILoT (Hierarchical Proving by Instantiation in Local Theory extensions), a program for hierarchical reasoning in extensions of logical theories. H-PILoT reduces deduction problems in the theory extension to deduction problems in the base theory. Specialized provers and standard SMT solvers can be used for testing the satisfiability of the formulae obtained after the reduction. For a certain type of theory extension (namely for local theory extensions) this hierarchical reduction is sound and complete and -- if the formulae obtained this way belong to a fragment decidable in the base theory -- H-PILoT provides a decision procedure for testing satisfiability of ground formulae, and can also be used for model generation.
Textual Description of annaffy Colin A. Smith
Bain, Mike
GOItem" @id "GO:0001657" @name "ureteric bud development" @type "Biological Process" @evid "IEA" [[2" @evid "IEA" [[3
Physical and Mathematical Description of Nuclear Weapons Identification System (NWIS) Signatures
Mattingly, J.K.; Mihalczo, J.T.; Mullens, J.A.; Valentine, T.E.
1997-09-26T23:59:59.000Z
This report describes all time and frequency analysis parameters measured with the new Nuclear Weapons Identification System (NWIS) processor with three input channels: (1) the 252Cf source ionization chamber (2) a detection channel; and (3) a second detection channel for active measurements. An intuitive and physical description of the various functions is given as well as a brief mathematical description and a brief description of how the data are acquired. If the fill five channel capability is used, the number of functions increases in number but not in type. The parameters provided by this new NWIS processor can be divided into two general classes: time analysis signatures including multiplicities and frequency analysis signatures. Data from measurements with an 18.75 kg highly enriched uranium (93.2 wt 0/0, 235U) metai casting for storage are presented to illustrate the various time and frequency analysis parameters.
Splitting of Folded Strings in AdS_4*CP^3
Jun-Bao Wu
2012-08-04T23:59:59.000Z
We study classically splitting of two kinds of folded string solutions in AdS_4*CP^3. Conserved charges of the produced fragments are computed for each case. We find interesting patterns among these conserved charges.
Constraints on Cosmic Strings from the LIGO-Virgo Gravitational-Wave Detectors
Aggarwal, Nancy
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 ...
Young, Diana S. (Diana Santos), 1975-
2007-01-01T23:59:59.000Z
Virtuosic bowed string performance in many ways exemplifies the incredible potential of human physical performance and expression. Today, a great deal is known about the physics of the violin family and those factors ...
Three-Charge Black Holes and Quarter BPS States in Little String Theory
Giveon, Amit; Kutasov, David; Lee, Sungjay
2015-01-01T23:59:59.000Z
We show that the system of $k$ NS5-branes wrapping $\\mathbb{T}^4\\times S^1$ has non-trivial vacuum structure. Different vacua have different spectra of 1/4 BPS states that carry momentum and winding around the $S^1$. In one vacuum, such states are described by black holes; in another, they can be thought of as perturbative BPS states in Double Scaled Little String Theory. In general, both kinds of states are present. We compute the degeneracy of perturbative BPS states exactly, and show that it differs from that of the corresponding black holes. We comment on the implication of our results to the black hole microstate program, UV/IR mixing in Little String Theory, string thermodynamics, the string/black hole transition, and other issues.
Mechanism of the Cassie-Wenzel transition via the atomistic and continuum string methods
Alberto Giacomello; Simone Meloni; Marcus Mueller; Carlo Massimo Casciola
2014-11-17T23:59:59.000Z
The string method is a general and flexible strategy to compute the most probable transition path for an activated process (rare event). We apply here the atomistic string method in the density field to the Cassie-Wenzel transition, a central problem in the field of superhydrophobicity. We discuss in detail the mechanism of wetting of a submerged hydrophobic cavity of nanometer size and its dependence on the geometry of the cavity. Furthermore, we discuss the algorithmic analogies between the string method and CREaM [Giacomello et al., Phys. Rev. Lett. 109, 226102 (2012)], a method inspired by the string that allows for a faster and simpler computation of the mechanism and of the free-energy profiles of the wetting process. This approach is general and can be employed in mesoscale and macroscopic calculations.
High-Energy String Scattering Amplitudes and Signless Stirling Number Identity
Jen-Chi Lee; Catherine H. Yan; Yi Yang
2012-07-18T23:59:59.000Z
We give a complete proof of a set of identities (7) proposed recently from calculation of high-energy string scattering amplitudes. These identities allow one to extract ratios among high-energy string scattering amplitudes in the fixed angle regime from high-energy amplitudes in the Regge regime. The proof is based on a signless Stirling number identity in combinatorial theory. The results are valid for arbitrary real values $L$ rather than only for $L=0,1$ proved previously. The identities for non-integer real value $L$ were recently shown to be realized in high-energy compactified string scattering amplitudes [He S., Lee J.C., Yang Y., arXiv:1012.3158]. The parameter $L$ is related to the mass level of an excited string state and can take non-integer values for Kaluza-Klein modes.
The Effective String of 3D Gauge Systems at the Deconfining Transition
M. Caselle; F. Gliozzi
1991-10-01T23:59:59.000Z
It is argued that the effective string of whatever 3D gauge system at the deconfining transition is universally described by the minimal $N=2$ extended superconformal theory at $c=1$. A universal value of the critical temperature is predicted.
Dilaton and axion bremsstrahlung from collisions of cosmic (super)strings
E. Yu. Melkumova; D. V. Gal'tsov; K. Salehi
2006-12-26T23:59:59.000Z
We calculate dilaton and axion radiation generated in the collision of two straight initially unexcited strings and give a rough cosmological estimate of dilaton and axion densities produced via this mechanism in the early universe.
University of Technology, Sydney
Assignment Types UTS LIBRARY February 2013 Academic Writing Guide Part 2 Assignment Types: This section outlines the basic types of written assignments, providing structural elements and examples. #12;2 II. Assignment Types 1. Essay Writing
Can a self-gravitating thin cosmic string obey the Nambu-Goto dynamics ?
B. Boisseau; C. Charmousis; B. Linet
1997-10-14T23:59:59.000Z
We assume that a self-gravitating string is locally described by a thin tube of matter represented by a ``smoothed conical metric''. If we impose a specific constraint on the model of string then its central line obeys the Nambu-Goto dynamics in the limit where the radius of the tube tends to zero. If no constraint is added then the world sheet of the central line is totally geodesic.
Methods and systems for determining angular orientation of a drill string
Cobern, Martin E. (Cheshire, CT)
2010-03-23T23:59:59.000Z
Preferred methods and systems generate a control input based on a periodically-varying characteristic associated with the rotation of a drill string. The periodically varying characteristic can be correlated with the magnetic tool face and gravity tool face of a rotating component of the drill string, so that the control input can be used to initiate a response in the rotating component as a function of gravity tool face.
Parametric description of the quantum measurement process
Pietro Liuzzo-Scorpo; Alessandro Cuccoli; Paola Verrucchi
2015-05-12T23:59:59.000Z
We present a description of the measurement process based on the parametric representation with environmental coherent states. This representation is specifically tailored for studying quantum systems whose environment needs being considered through the quantum-to-classical cross-over. Focusing upon projective measures, and exploiting the connection between large-$N$ quantum theories and the classical limit of related ones, we manage to push our description beyond the pre-measurement step. This allows us to show that the outcome production follows from a global-symmetry breaking, entailing the observed system's state reduction, and that the statistical nature of the process is brought about, together with the Born's rule, by the macroscopic character of the measuring apparatus.
Semiclassical circular strings in AdS{sub 5} and 'long' gauge field strength operators
Park, I.Y.; Tirziu, A.; Tseytlin, A.A. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States)
2005-06-15T23:59:59.000Z
We consider circular strings rotating with equal spins S{sub 1}=S{sub 2}=S in two orthogonal planes in AdS{sub 5} and suggest that they may be dual to long gauge-theory operators built out of self-dual components of gauge field strength. As was found in hep-th/0404187, the one-loop anomalous dimensions of the such gauge-theory operators are described by an antiferromagnetic XXX{sub 1} spin chain and scale linearly with length L>>1. We find that in the case of rigid rotating string both the classical energy E{sub 0} and the 1-loop string correction E{sub 1} depend linearly on the spin S (within the stability region of the solution). This supports the identification of the rigid rotating string with the gauge-theory operator corresponding to the maximal-spin (ferromagnetic) state of the XXX{sub 1} spin chain. The energy of more general rotating and pulsating strings also happens to scale linearly with both the spin and the oscillation number. Such solutions should be dual to other lower-spin states of the spin chain, with the antiferromagnetic ground state presumably corresponding to the string pulsating in two planes with no rotation.
Semiclassical Strings in Electric and Magnetic Fields Deformed $AdS_5 \\times S^5$ Spacetimes
Wung-Hong Huang
2006-01-06T23:59:59.000Z
We first apply the transformation of mixing azimuthal and internal coordinate or mixing time and internal coordinate to the 11D M-theory with a stack N M2-branes to find the spacetime of a stack of N D2-branes with magnetic or electric flux in 10 D IIA string theory, after the Kaluza-Klein reduction. We then perform the T duality to the spacetime to find the background of a stack of N D3-branes with magnetic or electric flux. In the near-horizon limit the background becomes the magnetic or electric field deformed $AdS_5 \\times S^5$. We adopt an ansatz to find the classical string solution which is rotating in the deformed $S^5$ with three angular momenta in the three rotation planes. The relations between the classical string energy and its angular momenta are found and results show that the external magnetic and electric fluxes will increase the string energy. Therefore, from the AdS/CFT point of view, the corrections of the anomalous dimensions of operators in the dual SYM theory will be positive. We also investigate the small fluctuations in these solutions and discuss the effects of magnetic and electric fields on the stability of these classical rotating string solutions. Finally, we find the possible solutions of string pulsating on the deformed spacetimes and show that the corrections to the anomalous dimensions of operators in the dual SYM theory are non-negative.
Proton Stability, Gauge Coupling Unification and a Light $Z^\\prime$ in Heterotic-string Models
Alon E. Faraggi; Viraf M. Mehta
2013-06-11T23:59:59.000Z
We explore the phenomenological viability of a light Z' in heterotic-string models, whose existence has been motivated by proton stability arguments. A class of quasi-realistic string models that produce such a viable Z' are the Left-Right Symmetric (LRS) heterotic-string models in the free fermionic formulation. A key feature of these models is that the matter charges under U(1)_Z' do not admit an E6 embedding. The light Z' in the LRS heterotic-string models forbids baryon number violating operators, while allowing lepton number violating operators, hence suppressing proton decay yet allowing for sufficiently small neutrino masses via a seesaw mechanism. We show that the constraints imposed by the gauge coupling data and heterotic-string coupling unification nullify the viability of a light Z' in these models. We further argue that agreement with the gauge coupling data necessitates that the U(1)_Z' charges admit an E6 embedding. We discuss how viable string models with this property may be constructed.
Macroscopic description for networks of spiking neurons
Ernest Montbrió; Diego Pazó; Alex Roxin
2015-06-22T23:59:59.000Z
A major goal of neuroscience, statistical physics and nonlinear dynamics is to understand how brain function arises from the collective dynamics of networks of spiking neurons. This challenge has been chiefly addressed through large-scale numerical simulations. Alternatively, researchers have formulated mean-field theories to gain insight into macroscopic states of large neuronal networks in terms of the collective firing activity of the neurons, or the firing rate. However, these theories have not succeeded in establishing an exact correspondence between the firing rate of the network and the underlying microscopic state of the spiking neurons. This has largely constrained the range of applicability of such macroscopic descriptions, particularly when trying to describe neuronal synchronization. Here we provide the derivation of a set of exact macroscopic equations for a network of spiking neurons. Our results reveal that the spike generation mechanism of individual neurons introduces an effective coupling between two biophysically relevant macroscopic quantities, the firing rate and the mean membrane potential, which together govern the evolution of the neuronal network. The resulting equations exactly describe all possible macroscopic dynamical states of the network, including states of synchronous spiking activity. Finally we show that the firing rate description is related, via a conformal map, with a low-dimensional description in terms of the Kuramoto order parameter, called Ott-Antonsen theory. We anticipate our results will be an important tool in investigating how large networks of spiking neurons self-organize in time to process and encode information in the brain.
Non-Abelian Born-Infeld Action and Type I - Heterotic Duality (II): Nonrenormalization Theorems
S. Stieberger; T. R. Taylor
2002-11-19T23:59:59.000Z
Type I - heterotic duality in D=10 predicts various relations and constraints on higher order F^n couplings at different string loop levels on both sides. We prove the vanishing of two-loop corrections to the heterotic F^4 terms, which is one of the basic predictions from this duality. Furthermore, we show that the heterotic F^5 and (CP even) F^6 couplings are not renormalized at one loop. These results strengthen the conjecture that in D=10 any Tr F^(2n) coupling appears only at the disc tree-level on type I side and at (n-1)-loop level on the heterotic side. Our non-renormalization theorems are valid in any heterotic string vacuum with sixteen supercharges.
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom
PART I: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Department Name: Student,1412 SIMON FRASER UNIVERSITY & C.U.P.E., Local 3338 JOB DESCRIPTION 1. POSITION IDENTIFICATION Department
PARTI: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom
PARTI: JOB DESCRIPTION Weighted Job Questionnaire (WJQ) Custom Meeting, Event and Conference UNIVERSITY & C.U.P.E., Local 3338 WEIGHTED JOB QUESTIONNAIRE (WJQ) CUSTOM PARTI: JOB DESCRIPTION 1. POSITION
Belavin, Alexander
2015-01-01T23:59:59.000Z
The fermionic NSR string possesses a hidden N = 2 superconformal algebra on the world-sheet. In this work, we show how to use an isomorphism of this algebra, the so-called spectral flow, for construction of a subspace of physical states of the string, on which space-time supersymmetry acts. This construction is an alternative to the GSO-projection in string theory.
STEP Energy Coach and Technical Consultant Job Descriptions
Broader source: Energy.gov [DOE]
STEP Energy Coach and Technical Consultant Job Descriptions, from the Tool Kit Framework: Small Town University Energy Program (STEP).
SY101 in situ viscometer instrument system design description
Pearce, K.L.; Stokes, T.I.; Vagelatos, N.
1994-08-18T23:59:59.000Z
This documents the design and description of the in situ viscometer, developed for the hydrogen mitigation project.
Fuzzy bags, Polyakov loop and gauge/string duality
Fen Zuo
2014-09-10T23:59:59.000Z
Confinement in SU($N$) gauge theory is due to the linear potential between colored objects. At short distances, the linear contribution could be considered as the quadratic correction to the leading Coulomb term. Recent lattice data show that such quadratic corrections also appear in the deconfined phase, in both the thermal quantities and the Polyakov loop. These contributions are studied systematically employing the gauge/string duality. "Confinement" in ${\\mathcal N}=4$ SU($N$) Super Yang-Mills (SYM) theory could be achieved kinematically when the theory is defined on a compact space manifold. In the large-$N$ limit, deconfinement of ${\\mathcal N}=4$ SYM on $\\mathbb{S}^3$ at strong coupling is dual to the Hawking-Page phase transition in the global Anti-de Sitter spacetime. Meantime, all the thermal quantities and the Polyakov loop achieve significant quadratic contributions. Similar results can also be obtained at weak coupling. However, when confinement is induced dynamically through the local dilaton field in the gravity-dilaton system, these contributions can not be generated consistently. This is in accordance with the fact that there is no dimension-2 gauge-invariant operator in the boundary gauge theory. Based on these results, we suspect that quadratic corrections, and also confinement, should be due to global or non-local effects in the bulk spacetime.
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Gleeson, Joseph G.
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