bluuebunny/crossref_metadata_2025 huggingface dataset:
ELLIPTIC OPERATORS AND SOLUTIONS OF COHOMOLOGICAL EQUATIONS FOR GEODESIC FLOWS WITH HYPERBOLIC BEHAVIOR
Authors: KATOK SVETLANA
Published: November 2004

In this paper we study the space of smooth functions on the unit tangent bundle SM to a compact negatively curved surface M that are eigenfunctions of the infinitesimal generator of the action of SO(2) on SM, and that have zero integrals over all periodic orbits of the geodesic flow on SM. It is proved that the space of such functions is finite dimensional. In the case of constant negative curvature a complete description of this space is obtained.
GEOMETRY OF HOMOGENEOUS HADAMARD MANIFOLDS
Authors: WOLTER THOMAS H.
Published: November 2004

Using result of R. Azencott and E. Wilson on the algebraic structure of homogeneous manifolds of nonpositive sectional curvature, we discuss the geometry of these manifolds and give several conditions how to distinguish the symmetric spaces among them.
Statistical Mechanics and Special-Purpose Computers
Authors: BLÖTE H.W.J.
Published: November 2004

A number of special-purpose computers (SPC’s) have been built in the last two decades, and more are under construction. In parallel with the evolution of generalpurpose computers, the capacity of the fastest SPC’s has grown considerably in this period. The increase of speed is partly due to the availability of faster components, but even more important is the introduction of new architectures using pipelining and parallel processing. Apart from becoming faster on the average, a pronounced diversification has taken place in SPC’s which does not only affect their speed but also their versatility and, of course, their cost.

An evaluation of SPC performances and costs in comparison with general-purpose supercomputers shows that, under certain circumstances, SPC’s can play a very useful role. They enable calculations that would not be feasible otherwise, because of excessive costs. However, the effort needed to build even a relatively simple SPC can easily be underestimated.
Derivation of Models for the Interacting Electrons in Cu-O Superconductors
Authors: MARTIN RICHARD M.
Published: November 2004

Key questions for theory of high temperature superconductors involve the nature of the electronic system: the minimum essential Hamiltonian and the low energy states of such Hamiltonians. To attempt to answer these questions we are carrying out studies using constrained density functional (CDF) methods to identify the relevant electronic states and realistic values of the parameters, combined with exact calculations on the reduced model Hamiltonians. The CDF calculations lead to a 3-band Hubbard model for Cu-O planes with parameters in general agreement with high energy spectroscopies and low energy magnetic excitations. We describe a modified Lanczos method to carry out large many-body calculations and give a representative result, where we find the spectra are described by the 1-band Hubbard model in regimes which imply spin interactions beyond the usual Heisenberg form.
Molecular Dynamics of Unstable Systems
Authors: COMPAGNER A. , BRUIN C. , BOKHOVE O.
Published: November 2004

Molecular-dynamics results for one- and two-dimensional systems of purely attractive particles are presented and are compared with a cell model.
Electron States in Static Disordered Systems and Fluid Systems
Authors: CRUZEIRO-HANSSON L. , BAUM J.O. , FINNEY J.L.
Published: November 2004

The path integral formulation of quantum statistical mechanics is used to study the effect of structural disorder on the electron states at finite temperatures. The following systems are investigated: an excess electron in a) a perfect hard spheres crystal, b) a hard spheres crystal with a vacancy and c) a hard spheres fluid. The localizing effect of a vacancy on the electron equals that of a fluid environment.
Simulation of Polycrystalline Film Growth
Authors: DAMMERS A.J. , RADELAAR S.
Published: November 2004

Thin solid films deposited from a vapour phase may exhibit a variety of morphological features. In the surface-diffusion dominated regime (no recrystallization) columnar structures with preferential crystallographic orientations develop, a phenomenon which has been frequently observed experimentally and which was explained qualitatively many years ago. We performed simulations of a two-dimensional model of such a system, consisting of randomly oriented squares, growing from a line. As a new result we find, that the characteristic length scale <Δx> of the growing surface (average edge length projected on the substrate) diverges as a function of time according to a power law <Δx>~tp, with p≈0.52.
Libraries and Development Environments for Monte Carlo Simulations of Lattice Gauge Theories on Parallel Computers
Authors: DECKER K.M. , JAYEWARDENA C. , REHMANN R.
Published: November 2004

We describe the library lgtlib, and lgttool, the corresponding development environment for Monte Carlo simulations of lattice gauge theory on multiprocessor vector computers with shared memory. We explain why distributed memory parallel processor (DMPP) architectures are particularly appealing for compute-intensive scientific applications, and introduce the design of a general application and program development environment system for scientific applications on DMPP architectures.
Graphical Concepts for the Representation of Events in High Energy Physics
Authors: DREVERMANN H. , GRAB C. , NILSSON B.S. , VOGL R.K.
Published: November 2004

Different methods to graphically represent points and tracks of events, measured with the ALEPH-detector at LEP, are discussed. Special emphasis is put on projections, that are adapted to the cylindrical geometry of the detector, to the track geometry of charged particles moving in a homogeneous magnetic field and to the specific event topologies, encountered in Z0 physics.

A new concept, the so-called “V-plot”, is introduced, which incorporates the full three dimensional information of spatial points in a single picture. It is ideally suited for the study of more complicated event topologies, such as e.g. decays of particles within jets, and of the correlation between information from tracking and calorimetric devices.

In addition, we propose ways of combining histograms and projections in a single picture. We describe methods of employing colour schemes to facilitate recognition of correlations between hits, tracks and/or subdetectors in different representations.
Non-axisymmetric Unstable Modes in a Thin Differentially Rotating Gaseous Disk
Authors: HEEMSKERK M.H.M. , SAVONIJE G.J.
Published: November 2004

We consider the linear stability of a thin differentially rotating gaseous disc with reflecting boundaries against non-axisymmetric perturbations. We assume the unperturbed disc to be in centrifugal equilibrium with the gravitational attraction of a central mass M, and consider discs whose mass can be neglected relative to M. We discuss the relevant conservation laws for the energy and angular momentum of linear non-axisymmetric modes in a thin rotating disc without self-gravity and illustrate the basic mode amplification mechanisms with help of some of our numerical solutions [1].
Monte Carlo Simulations of Lattice Gases Exhibiting Quantum Statistical Distributions
Authors: PRZENIOSŁO R. , BARSZCZAK T. , KUTNER R. , GUZICKI W. , RENZ W.
Published: November 2004

A non-interacting lattice gas with order preservation in a constant external field is studied by numerical and analytical methods. The equilibrium distribution is of the Bose-Einstein type. If additional hard-core repulsion is imposed, it becomes a distribution of Fermi-Dirac type. When relaxing the order preservation condition the classical Boltzmann distribution is recovered.
POWER-LAW TYPE SOLUTIONS OF FOURTH-ORDER GRAVITY FOR MULTIDIMENSIONAL BIANCHI I UNIVERSES
Authors: CAPRASSE H. , DEMARET J. , GATERMANN K. , MELENK H.
Published: November 2004

This paper is devoted to the application of computer algebra to the study of solutions of the field equations derived from a non-linear Lagrangian, as suggested by recently proposed unified theories. More precisely, we restrict ourselves to the most general quadratic Lagrangian, i.e. containing quadratic contributions in the different curvature tensors exclusively. The corresponding field equations are then fourth-order in the metric tensor components. The cosmological models studied are the simplest ones in the class of spatially homogeneous but anisotropic models, i.e. Bianchi I models. For these models, we consider only power-law type solutions of the field equations. All the solutions of the associated system of algebraic equations are found, using computer algebra, from a search of its Groebner bases. While, in space dimension d=3, the Einsteinian-Kasner metric is still the most general power-law type solution, for d>3, no solution, other than the Minkowski space-time, is common to the three systems of equations corresponding to the three contributions to the Lagrangian density. In the case of a pure Riemann-squared contribution to the Lagrangian (suggested by a recent calculation of the effective action for the heterotic string), the possibility exists to realize a splitting of the d-dimensional space into a (d−3)-dimensional internal space and a physical 3-dimensional space, the latter expanding in time as a power bigger than 2 (about 4.5 when d=9).
BROWNIAN DYNAMICS SIMULATIONS WITHOUT GAUSSIAN RANDOM NUMBERS
Authors: DÜNWEG BURKHARD , PAUL WOLFGANG
Published: November 2004

We point out that in a Brownian dynamics simulation it is justified to use arbitrary distribution functions of random numbers if the moments exhibit the correct limiting behavior prescribed by the Fokker-Planck equation. Our argument is supported by a simple analytical consideration and some numerical examples: We simulate the Wiener process, the Ornstein-Uhlenbeck process and the diffusion in a Φ4 potential, using both Gaussian and uniform random numbers. In these examples, the rate of convergence of the mean first exit time is found to be nearly identical for both types of random numbers.
CONFLICT-FREE STRIDES FOR VECTORS IN MATCHED MEMORIES
Authors: VALERO MATEO , LANG TOMÁS , LLABERÍA JOSÉ M. , PEIRON MONTSE , NAVARRO JUAN J. , AYGUADÉ EDUARD
Published: November 2004

Address transformation schemes, such as skewing and linear transformations, have been proposed to achieve conflict-free access to one family of strides in vector processors with matched memories.

In this paper, we extend these schemes to achieve this conflict-free access for several families. The basic idea is to perform an out-of-order access to vectors of fixed length, equal to that of the vector registers of the processor. The hardware rcquired is similar to that for the access in order.
SUBCUBE EMBEDDABILITY OF FOLDED HYPERCUBES
Authors: LATIFI SHAHRAM
Published: November 2004

The Folded Hypercube (FHC) has been proven to be an attractive hypercube-based network. This paper closely compares the FHC to its standard hypercube counterpart from the subcube allocation viewpoint. It is shown that the FHC(n) outperforms the n-dimensional hypercube (n-cube for short) in offering subcubes of size k by a factor of [Formula: see text]. In an environment where subcubes of the original network must be allocated to incoming tasks, the FHC achieves an excellent processor utilization by assigning subcubes in an efficient and compact manner. Using the concept of virtual hypercubes, an efficient way is suggested to recognize the available subcubes in the FHC by adapting the already developed subcube recognition algorithms. An alternative approach to the subcube recognition problem is also given.
MODELLING A MORPHOLOGICAL THINNING ALGORITHM FOR SHARED MEMORY SIMD COMPUTERS
Authors: DATTA ABHIJIT , JOSHI SHIRISH V. , MAHAPATRA RABI N.
Published: November 2004

This letter presents the modelling of a morphological thinning algorithm suggested by Jang and Chin [1] on the four models of shared memory SIMD computers. The time and cost complexity analyses for the models have been given. The performance of this algorithm on SIMD computers has been compared with the performance of a conventional thinning algorithm [2] proposed recently.
A NOTE ON OFF-LINE PERMUTATION ROUTING ON A MESH-CONNECTED PROCESSOR ARRAY
Authors: KRIZANC DANNY
Published: November 2004

We show how to off-line route any permutation of an n×n mesh-connected processor array in 2.5n steps with at most two packets per processor per time step and in 2.25n+3 steps with at most four packets per processor per time step.
HARTREE APPROXIMATION FOR QCD AT FINITE TEMPERATURE
Authors: THOMA MARKUS H.
Published: November 2004

The gluon propagator in Coulomb gauge is calculated at finite temperature using the Hartree approximation for the Dyson-Schwinger equation.
GRAVITATIONAL PARTICLE PRODUCTION BY COSMIC TEXTURES
Authors: PULLIN JORGE , VERDAGUER ENRIC
Published: November 2004

Using a perturbative technique we compute the rate of particle production in the evolution of a cosmic texture, based on the stress energy tensor introduced by Turok and Spergel. We compare the results with those for other topological defects.
RADIATIVE CORRECTIONS TO HIGGS MASSES IN THE SUPERSYMMETRIC MODEL WITH AN EXTRA FAMILY AND ANTI-FAMILY
Authors: MOROI TAKEO , OKADA YASUHIRO
Published: November 2004

Radiative corrections to Higgs masses are calculated in a supersymmetric standard model with an extra family and its mirror partners. These corrections, in general, depend on the mass spectrum of fermions, bosons and the strength of Yukawa couplings of the extra families. If we assume that the Yukawa couplings do not blow up below the GUT scale, the upper bound of the lightest Higgs mass increases about 12 GeV. We also notice that, in some cases, the charged Higgs mass becomes lighter than that of the tree level prediction.
GAUGE INVARIANT, RENORMALIZABLE, AND UNITARY CHIRAL THEORY
Authors: KIEU T.D.
Published: November 2004

A non-polynomial quantization for chiral gauge interactions is motivated. It is shown for Abelian group in four dimensions that the quantization, manifestly local in the Lorentz gauge, is consistent: simultaneously satisfying the requirements of gauge invariance, (perturbative) renormalizability, and unitarity. Chiral photons can be massive in the framework without invoking the Higgs mechanism. Non-Abelian generalization is then speculated.
CALCULABLE FERMION MASSES IN A QUARK-LEPTON SYMMETRIC MODEL
Authors: FOOT R. , LEW H.
Published: November 2004

The quarks and leptons appear tantalizingly similar at present energies. One explanation of this is that quarks and leptons are exactly symmetrical, but this symmetry has been broken by the vacuum. In gauge models with this feature, there are typically tree-level mass relations between quarks and leptons. We show that these mass relations may be modified by radiative effects so that they agree with experiment.
EVADING THE TOP MASS BOUND IN THE FRITZSCH SCHEME
Authors: RAJPOOT SUBHASH
Published: November 2004

The Fritzsch ansatz for the quark mass matrices will run into conflict with the existing data on the Cabibbo-Kobyashi-Maskawa mixing angles if the top quark mass turns out to be much greater than 90 GeV. A modification of the Fritzsch scheme is presented in which only one diagonal element of the quark mass matrix vanishes. The new scheme is still simple to analyze exactly and can easily accommodate top quark mass as heavy as 250 GeV or more without conflicting with our present knowledge on the weak interaction mixing angles.
BACKWARDS TIME-TRAVEL INDUCED BY COMBINED MAGNETIC AND GRAVITATIONAL FIELDS
Authors: NOVELLO M. , SVAITER N.F. , GUIMARÃES M.E.X.
Published: November 2004

In this work, we analyze the behavior of a macroscopic particle submitted to combined magnetic and gravitational fields on Gödel’s Universe. The examination is made in a local Gaussian system of coordinates.
THE “HIGGS ALGEBRA” AS A ‘QUANTUM’ DEFORMATION OF SU(2)
Authors: ZHEDANOV A.S.
Published: November 2004

The Higgs algebra (i.e., the hidden symmetry algebra of the Coulomb problem in the two-dimensional space of constant curvature) is investigated. Consisting of 3 generators, the Higgs algebra can be considered as a second-order approximation to SU q(2). ‘Classical’ and ‘nonclassical’ representations and realizations of the Higgs algebra are found.Connections with other Lie and quadratic algebras are discussed.
TWO-DIMENSIONAL QUANTUM GRAVITY ON A DISK
Authors: TANII YOSHIAKI , YAMAGUCHI SHUN-ICHI
Published: November 2004

We study a two-dimensional conformal field theory coupled to quantum gravity on a disk. Using the continuum Liouville field approach, we compute three-point correlation functions of boundary operators. The structure of momentum singularities is different from that of correlation functions on a sphere and is more complicated. We also compute four-point functions of boundary operators and three-point functions of two boundary operators and one bulk operator.
LIGHT LEPTOQUARKS AS POSSIBLE SIGNATURE OF STRONG-ELECTROWEAK UNIFICATION
Authors: FRAMPTON PAUL H.
Published: November 2004

In strong-electroweak unification, based on SU(15), with baryon number (B) and lepton number (L) conserved, bosons with B=±2/3, L=0 (diquarks), B=0, L=±2 (dileptons) and B=±1/3, L=±1 (leptoquarks) can occur at “light” (≤ TeV) scales. The discovery of light leptoquarks would be evidence as compelling as proton decay for grand unification.
NO-BOUNDARY WAVE FUNCTION IN A HIGHER-DIMENSIONAL SPHERICALLY SYMMETRIC MICROSUPERSPACE MODEL
Authors: CHAKRABORTY SUBENOY
Published: November 2004

The wave function following the Hartle-Hawking (HH) no-boundary proposal is evaluated in five-dimensional space-time with topology of the four space S1×S3, generalizing the concept of microsuperspace. The functional integral in the expression for the wave function is simplified to an ordinary integration of one variable and is evaluated by the method of steepest-descent.
RANK-ONE MASS MATRIX AND PHENOMENOLOGICAL CONSTRAINTS
Authors: SAMAL MANOJ K.
Published: November 2004

We give the phenomenological constraints for a scheme which was recently proposed to investigate the approximately symmetric KM matrix in relation to the rank-one quark mass matrices. The allowed ranges for the parameters in this scheme are given. It is shown that out of the three interesting solutions of the symmetric KM matrix discussed in this scheme one is inconsistent with experiments, whereas another one requires a very heavy top quark mass (m t ≈255 GeV ) to be consistent.
INFLATION FROM STRINGS II: REHEATING AND BARYOGENESIS
Authors: BENTO M.C. , BERTOLAMI O. , SÁ P.M.
Published: November 2004

We study the reheating process which takes place after the two periods of inflation that arise from a string-inspired cosmological model. Baryogenesis mechanisms and a possible solution for the magnetic monopole problem that are compatible with string-motivated inflationary scenarios are discussed.
THE PROPERTIES OF MATTER IN KALUZA-KLEIN COSMOLOGY
Authors: WESSON PAUL S.
Published: November 2004

The physics contained in perfect-fluid, spatially-flat cosmological solutions of Gij=Tij (4D) is contained in the equations Gij=0 (5D), provided the fifth dimension is properly interpreted. This implies that matter is a manifestation of the fifth dimension.
ABNORMAL PROPAGATION IN THE SKYRME MODEL
Authors: YAMAGISHI HIDENAGA , ZAHED ISMAIL
Published: November 2004

It is shown that the Skyrme Lagrangian exhibits abnormal propagation effects similar to those analyzed by Velo and Zwanziger for higher spin fields. The difficulty does not arise for the vector stabilized versions. Implications for the chiral soliton program are briefly discussed.
RENORMALIZATION OF YUKAWA THEORY WITH A KERNEL IN STOCHASTIC QUANTIZATION
Authors: KAPOOR A.K. , KOMOIKE N. , OHBA I. , SANDHYA R. , TANAKA S.
Published: November 2004

In this paper, renormalization of massive fermionic theory with a kernel, when fermions are coupled to bosons via Yukawa coupling is studied. It is shown that the theory is indeed renormalizable by proving that no new counterterms appear in the renormalized action.
ON THE PHASE OF ε AND THE NA31 BOUND ON CPT VIOLATION
Authors: LAVOURA L.
Published: November 2004

I discuss the theoretical prediction for the phase of the CP-violating parameter ε, and the experimental bound on the CPT-violating contribution to that parameter. I conclude that, if one neglects theoretical prejudices and only takes into account the experimental data, the phase of ε may differ by as much as four degrees from the superweak phase. The present experimental bound on CPT violation cannot be much strengthened if one does not first obtain better bounds on the CP violation in the three-pion decay modes.
TOPOLOGICAL SPIN-STATISTICS THEOREMS FOR STRINGS
Authors: BALACHANDRAN A.P. , McGLINN W.D. , O’RAIFEARTAIGH L. , SEN S. , SORKIN R.D. , SRIVASTAVA A.M.
Published: November 2004

Recently, a topological proof of the spin-statistics theorem has been proposed for a system of point particles. It does not require relativity or field theory, but assumes the existence of antiparticles. We extend this proof to a system of string loops in three space dimensions and show that by assuming the existence of antistring loops, one can prove a spin-statistics theorem for these string loops. According to this theorem, all unparametrized strings (such as flux tubes in superconductors and cosmic strings) should be quantized as bosons. Also, as in the point particle case, we find that the theorem excludes non-Abelian statistics.
AN ALGORITHM TO GENERATE CLASSICAL SOLUTIONS OF STRING EFFECTIVE ACTION
Authors: KAR SUPRIYA K. , KHASTGIR S. PRATIK , KUMAR ALOK
Published: November 2004

It is shown explicitly that a number of solutions for the background field equations of the string effective action in space-time dimension D can be generated from any known lower dimensional solution when background fields have only time dependence. An application of the result to the two-dimensional charged black hole is presented. The case of background with more general coordinate dependence is also discussed.
CRITICAL BEHAVIOR OF (2+1)-DIMENSIONAL CPN−1 MODEL WITH A CHERN-SIMONS TERM
Authors: PARK SEON H.
Published: November 2004

I investigate the critical behavior of (2+1)-dimensional CPN−1 model with a Chern-Simons term. I derive the 1/N expansion in this model and show that the theory is renormalizable in this framework. The critical exponents η and υ are calculated to the O(1/N). They exhibit θ (coefficient of the Chern-Simons term) dependence.
A MODEL OF THREE-DIMENSIONAL LATTICE GRAVITY
Authors: BOULATOV D.V.
Published: November 2004

A model is proposed which generates all oriented 3D simplicial complexes weighted with an invariant associated with a topological lattice gauge theory. When the gauge group is SUq(2), qn=1, it is the Turaev-Viro invariant and the model may be regarded as a nonperturbative definition of 3D simplicial quantum gravity. If one takes a finite Abelian group G, the corresponding invariant gives the rank of the first cohomology group of a complex C:IG(C)=rank(H1(C,G)), which means a topological expansion in the Betti number b1. In general, it is a theory of the Dijkgraaf-Witten type, i.e., determined completely by the fundamental group of a manifold.
CLASSICAL YANG-BAXTER EQUATIONS AND QUANTUM gl(p, q)-GAUDIN MODEL
Authors: XI-WEN GUAN , ZHUANG XIONG , HUAN-QIANG ZHOU
Published: November 2004

A completely integrable Gaudin model associated with the Lie superalgebra gl(p, q) is presented, and its integrability is demonstrated in a straightforward way.
SYMPLECTIC QUANTIZATION OF CONSTRAINED SYSTEMS
Authors: BARCELOS-NETO J. , WOTZASEK C.
Published: November 2004

It is shown that the symplectic two-form, which defines the geometrical structure of a constrained theory in the Faddeev-Jackiw approach, may be brought into a non-degenerated form, by an iterative implementation of the existing constraints. The resulting generalized brackets coincide with those obtained by the Dirac bracket approach, if the constrained system under investigation presents only second-class constraints. For gauge theories, a symmetry breaking term must be supplemented to bring the symplectic form into a non-singular configuration. At present, the singular symplectic two-form provides directly the generators of the time independent gauge transformations.
MULTIHADRON PRODUCTION AND A MODIFICATION OF POLYAKOV’S FORM
Authors: BARSHAY SAUL , HEILIGER PATRICK
Published: November 2004

We compare a modification of the general structure of hadronic multiplicity distributions, derived by Polyakov from the dynamics of quantum field theory with a similarity hypothesis, to the multiplicity data at the present highest energy, [Formula: see text]. We emphasize the physical impact of Polyakov’s dynamics in the context of the possibility that limiting (asymptotic) behavior is nearly reached only at much higher energies ~1000 TeV.
MEASURING THE $H t\bar t$ COUPLING IN e+e− COLLISIONS
Authors: DJOUADI A. , KALINOWSKI J. , ZERWAS P.M.
Published: November 2004

Higgs radiation off heavy top quarks in high-energy e+e− colliders may be exploited to measure the Higgs-top quark coupling. We explore the mass range for which the process [Formula: see text] provides access to this fundamental parameter in the Standard Model.
ON THE INTERACTION OF BUBBLES WITH GRAVITATIONAL AND MATTER FIELDS
Authors: WANG ANZHONG
Published: November 2004

The space-time containing a single spherically symmetric bubble is studied by using the distribution theory. The Einstein equations on the bubble wall are given explicitly in terms of the discontinuities of metric coefficients and their derivatives, The interaction of a bubble with surrounding gravitational and matter fields is also investigated by the “generalized” Bianchi identities. In particular, it is found that an electromagnetic field does not interact with any bubble, and is continuous across the bubble wall without reflecting or absorbing, while the interaction of a bubble produced with a scalar field or a perfect fluid is possible.
GEOMETRIC LIOUVILLE GRAVITY
Authors: LA HOSEONG
Published: November 2004

A new geometric formulation of Liouville gravity based on the area preserving diffeomorphism is given and a possible alternative to reinterpret Liouville gravity is suggested, namely, a scalar field coupled to two-dimensional gravity with a curvature constraint.
QUANTUM ELECTRODYNAMICS AT $O\left( {{1 \mathord{\left/ {\vphantom {1 {N_f^2 }}} \right. \kern-\nulldelimiterspace} {N_f^2 }}} \right)$ IN ARBITRARY DIMENSIONS
Authors: GRACEY JA.
Published: November 2004

We give an analytic expression for the critical exponent η, which is related to the electron anomalous dimension, at [Formula: see text] in the large-Nf expansion in arbitrary dimensions in the Landau gauge.
QUANTUM MODEL FOR SPACE-TIME
Authors: CHAPLINE GEORGE
Published: November 2004

It is suggested that a recently constructed condensate wave function for a three-dimensional anyonic superfluid can be reinterpreted as a coherent state for gravitons. This wave function provides for the first time a mathematical model showing how macroscopic space-time might emerge from microscopic fluctuations in topology, and suggests that the observable universe may be in a nearly pure quantum state.
CRITICAL BEHAVIOR FROM SCHRÖDINGER REPRESENTATION
Authors: SURANYI P.
Published: November 2004

The Schrödinger equation for Φ4 field theory is reduced to an infinite set of integral equations. A systematic truncation scheme is proposed and it is solved in second order to obtain the approximate critical behavior of the renormalized mass. The correlation exponent is given as a solution of a transcendental equation. It is in good agreement with the Ising model in all physical dimensions.
VECTOR MESON DOMINANCE IN THE VECTOR MODEL
Authors: CAMPERI MARCELO , FAYYAZUDDIN ANSAR
Published: November 2004

We show that Vector Meson Dominance cannot be recovered in the so-called vector model when higher order corrections are included.
QUANTUM EFFECTS NEAR THE BLACK HOLE SINGULARITY IN KRUSKAL SPACE-TIME
Authors: KRORI K. D. , BORGOHAIN P. , DAS KAR DIPALI
Published: November 2004

We show that the conclusion by Joshi and Joshi [Class. Quantum Grav.5, L191 (1988)] that there will be infinite quantum fluctuations as the singularity is approached in Kruskal space-time needs modification.
ELECTRIC DIPOLE MOMENT OF NEUTRON IN A FIELD THEORETIC QUARK MODEL
Authors: MAHARANA L. , NATH A. , PANDA A. R.
Published: November 2004

Electric Dipole Moment of Neutron (EDMN) is considered in a field theoretic quark model of composite hadrons. For this purpose CP-violating QCD interaction is used and the calculation is based on the second order perturbation. With harmonic oscillator radius of neutron as a free parameter, the theoretical analysis is observed to agree reasonably well with the experiment.
ENTROPY, DIMENSIONS AND OTHER MULTIFRACTAL CHARACTERISTICS OF MULTIPLICITY DISTRIBUTIONS
Authors: PACHR M. , ŠIMÁK V. , ŠUMBERA M. , ZBOROVSKÝ I.
Published: November 2004

Entropy scaling of multiplicity distributions is shown to be a special case of more general set of multifractal measures. We perform an analysis multiplicity distributions of data from hadron-hadron and electron-positron interactions.
ABOUT SOME EXACT SOLUTIONS FOR 2 + 1 GRAVITY COUPLED TO GAUGE FIELDS
Authors: KOGAN IAN I.
Published: November 2004

Some exact static solutions for Einstein gravity in 2 + 1 dimensions coupled to Abelian gauge field are discussed, where the invariant interval is of the form: ds2 = N2 (r) dt2 − dr2 − C2 (r) dθ2. Some of these solutions are three-dimensional analogs of the Schwarzschild black holes. The metrics in the regions inside and outside the horizon are connected by the changing of the Planck mass sign.
THE ALGEBRA OF SUPERTRACES FOR (2 + 1) SUPER DE SITTER GRAVITY
Authors: URRUTIA L. F. , WAELBROECK H. , ZERTUCHE F.
Published: November 2004

We calculate the algebra of the observables for 2 + 1 super de Sitter gravity, for one genus of the spatial surface. The algebra turns out to be an infinite Lie algebra subject to nonlinear constraints. We solve the constraints explicitly in terms of five independent complex supertraces. These variables are the true degrees of freedom of the system and their quantized algebra generates a new structure which we refer to as a "central extension" of the quantum algebra SU (2)q.
YANG-MILLS FIELD QUANTIZATION WITH NON-COMPACT GAUGE GROUP
Authors: MARGOLIN A. E. , STRAZHEV V. I.
Published: November 2004

Yang-Mills field quantization in BRST-formalism with non-compact semi-simple gauge group is performed. The S-matrix unitarity in the physical state space, having indefinite metric is determined.
ASYMPTOTIC DENSITY OF STATES OF p-BRANES
Authors: ÁLVAREZ ENRIQUE , ORTÍN TOMÁS
Published: November 2004

The asymptotic form of the density of states for a p-brane is computed (using the semi-classical approximation for the expression of the mass formula), and a value is found which only resembles the exponential growth of black holes in the formal limit p → ∞. Some physical consequences for the thermodynamics of these objects are also presented.
FRACTIONAL SUPERSPACE FORMULATION OF GENERALIZED SUPER-VIRASORO ALGEBRAS
Authors: DURAND STÉPHANE
Published: November 2004

We present a fractional superspace formulation of the centerless parasuper- Virasoro and fractional super-Virasoro algebras. These are two different generalizations of the ordinary super-Virasoro algebra generated by the infinitesimal diffeomorphisms of the superline. We work on the fractional superline parametrized by t and θ, with t a real coordinate and θ a paragrassmann variable of order M and canonical dimension 1/F. We further describe a more general structure labeled by M and F with M ≥ F. The case F = 2 corresponds to the parasuper-Virasoro algebra of order M, while the case F = M leads to the fractional super-Virasoro algebra of order F. The ordinary super-Virasoro algebra is recovered at F = M = 2. The connection with q-oscillator algebras is discussed.
IRREVERSIBILITY OF THE RENORMALIZATION GROUP FLOW IN TWO-DIMENSIONAL QUANTUM GRAVITY
Authors: KUTASOV DAVID
Published: November 2004

We argue that the torus partition sum in 2D (super) gravity, which counts physical states in the theory, is a decreasing function of the renormalization group scale. As an application we chart the space of [Formula: see text] models coupled to (super) gravity, confirming and extending ideas due to A. Zamolodchikov, and discuss briefly string theory, where our results imply that the number of degrees of freedom decreases with time.
N = ½ SUPERSTRING IN ZERO DIMENSION AND THE SPONTANEOUS BREAKDOWN OF THE SUPERSYMMETRY
Authors: NOJIRI SHIN’ICHI
Published: November 2004

We propose random matrix models which have N=1/2 supersymmetry in zero dimension. The supersymmetry breaks down spontaneously. It is shown that the double scaling limit can be defined in these models and the breakdown of the supersymmetry remains in the continuum limit. The exact non-trivial partition functions of the string theories corresponding to these matrix models are also obtained.
SIEGEL GAUGE INVARIANCE AND QUANTIZATION
Authors: MITRA P.
Published: November 2004

The quantization of chiral bosons, which is important in the context of the heterotic string, has been a controversial subject. On one hand, there is a straightforward Hamiltonian approach, which, however, is not manifestly Lorentz invariant. On the other hand, there is an inequivalent Lagrangian approach, with a special gauge invariance which is believed to become anomalous. In an attempt to throw some light on the problem, we analyze a simple quantum mechanical system with a similar gauge invariance and compare the two approaches. The Hamiltonian approach turns out to be the one giving the “correct” result.
YUKAWA COUPLINGS FOR BOSONIC ZN ORBIFOLDS: THEIR MODULI AND TWISTED SECTOR DEPENDENCE
Authors: STIEBERGER S. , JUNGNICKEL D. , LAUER J. , SPALIŃSKI M.
Published: November 2004

The three-point correlation functions with twist fields are determined for bosonic ZN orbifolds. Both the choice of the modular background (compatible with the twist) and of the (higher) twisted sectors involved are fully general. We point out a necessary restriction on the set of instantons contributing to twist field correlation functions not obtained in previous calculations. Our results show that the theory is target space duality invariant.
MATRIX MODEL PERTURBED BY HIGHER ORDER CURVATURE TERMS
Authors: KORCHEMSKY G.P.
Published: November 2004

The critical behavior of the D=0 matrix model with the potential perturbed by a nonlocal term generating touchings between random surfaces is studied. It is found that the phase diagram of the model has many features of the phase diagram of discretized Polyakov’s bosonic string with higher order curvature terms included. It contains the phase of smooth (Liouville) surfaces, the intermediate phase and the phase of branched polymers. The perturbation becomes irrelevant at the first phase and dominates at the third one.
NON-RELATIVISTIC FERMIONS, COADJOINT ORBITS OF W∞ AND STRING FIELD THEORY AT c=1
Authors: DHAR AVINASH , MANDAL GAUTAM , WADIA SPENTA R.
Published: November 2004

We apply the method of coadjoint orbits of W∞-algebra to the problem of non-relativistic fermions in one dimension. This leads to a geometric formulation of the quantum theory in terms of the quantum phase space distribution of the Fermi fluid. The action has an infinite series of expansion in the string coupling, which to leading order reduces to the previously discussed geometric action for the classical Fermi fluid based on the group w∞ of area-preserving diffeomorphisms. We briefly discuss the strong coupling limit of the string theory which, unlike the weak coupling regime, does not seem to admit a two-dimensional space-time picture. Our methods are equally applicable to interacting fermions in one dimension.
SPONTANEOUS CP VIOLATION IN A TWO-GENERATION LEFT-RIGHT SYMMETRIC MODEL WITH TWO HIGGS BI-DOUBLETS
Authors: GHOSAL AMBAR , RAY ASIM K. , SARKAR SASWATI
Published: November 2004

We discuss a two-generation left-right symmetric model with two Higgs bi-doublets and a discrete symmetry to show that spontaneous CP violation arises as a result of soft breaking of the discrete symmetry. The contributions to the CP violation parameter ε in the [Formula: see text] transition come from the box diagrams due to WL-WR exchanges as well as from the mixing of the real and imaginary parts of the flavor changing neutral Higgs at the tree level and both contributions depend on the relative phase difference between the vacuum expectation values (vevs) of the relevant neutral Higgs scalars. Other CP violating effects in the model are consistent with their experimental values for the appropriate choice of the model parameters. The extension of the model to the realistic case of three generations of fermions does not appreciably change the phenomenology of the model.
THE PHOTON STRUCTURE FUNCTION IN HIGHER ORDERS OF QCD
Authors: BUTTERY R.J. , STORROW J.K.
Published: November 2004

The singularities at x=0 in the calculable point-like part of the photon structure function [Formula: see text] are expected to be increasingly severe in higher orders of QCD. Starting from the inhomogeneous Altarelli-Parisi equations a simple and transparent proof of this result is given which emphasizes how these singularities arise and also shows how they are automatically regularized by including input from a reference [Formula: see text]. The behavior of the singularities in higher orders is studied. The effect of this on the validity of using the calculable asymptotic solution is discussed.
NUMERICAL ANALYSIS OF GUTs PREDICTIONS IN THE LIGHT OF RECENT RESULTS FROM LEP
Authors: GRECH DARIUSZ
Published: November 2004

We find numerical best fit for sin 2 Θw(MZ), unifying mass MX and the proton lifetime τp as the outcome of analysis where experimental values of Z boson mass MZ, strong coupling constant αs(MZ) and electromagnetic coupling α0(MZ) are taken as the only input parameters. It is found that simple nonsupersymmetric models are unlikely to be realistic ones. On the other hand, we find the best numerical fit: sin 2Θw(MZ = 0.2330 ± 0.0007 (theor.) ± 0.0027 (exp.) , [Formula: see text] yr for supersymmetric unified theories with three generations. The central values require, however, that the supersymmetric mass Λs≲300 GeV . Possibilities of increasing this limit as well as cases with four generations and threshold effects are also discussed. Compact formulas for theoretical and experimental uncertainties involved in the analysis are also produced.
REMARKS CONCERNING POLYAKOV’S CONJECTURE FOR THE 3D ISING MODEL AND THE HIERARCHICAL APPROXIMATION
Authors: MEURICE YANNICK
Published: November 2004

We consider the possibility of using the hierarchical approximation to understand the continuum limit of a reformulation of the 3D Ising model initiated by Polyakov. We introduce several new formulations of the hierarchical model using dual or fermionic variables. We discuss several aspects of the renormalization group transformation in terms of these new variables. We mention a reformulation of the model closely related to string models proposed by Zabrodin.
THERMODYNAMICS OF TWO-DIMENSIONAL BLACK HOLES
Authors: NAPPI CHIARA R. , PASQUINUCCI ANDREA
Published: November 2004

We explore the thermodynamics of a general class of two-dimensional dilatonic black holes. A simple prescription is given that allows us to compute the mass, entropy and thermodynamic potentials, with results in agreement with those obtained by other methods, when available.
AN W ALGEBRAS AND CLASSIFICATION
Authors: CHAO LIU , HOU BOYU
Published: November 2004

The necessary and sufficient conditions for the existence of a regular element of arbitrary degree under arbitrary integral gradation of the Lie algebra g is presented. Such elements, while chosen as constraints in WZNW model, give rise to a W-algebra. It is then found that there might be some isomorphic relations between different W-algebras. The necessary conditions for such isomorphisms to appear are also given. Up to the A4 cases these conditions are checked to be sufficient.
INITIAL STATE SCATTERING AND J/Ψ HADROPRODUCTION ON NUCLEI
Authors: SALEEV V.A. , ZOTOV N.P.
Published: November 2004

The pT-spectra of J/Ψ in hadron-nucleus and nucleus-nucleus collisions at high energies are investigated in a model where gg→J/Ψg is assumed to be the dominant mechanism. The initial state scattering using the additive quark models is taken into account.

We demonstrate good agreement between the J/ΨpT-spectra and our results. It is shown that the allowance for the quark re-scattering and J/Ψ absorption in nuclear matter makes it possible to describe at least the major part of the J/Ψ suppression effect in collisions of relativistic nuclei.
EQUATIONS OF MOTION FOR d=3 MASSLESS FIELDS INTERACTING THROUGH CHERN-SIMONS HIGHER-SPIN GAUGE FIELDS
Authors: VASILIEV M.A.
Published: November 2004

We formulate totally consistent nonlinear equations of motion for massless scalar and spinor fields in 2+1 dimensions interacting through Chern-Simons higher-spin gauge fields. The dynamical systems under consideration can be interpreted either as higher-spin massless anyons in 2+1 dimensions or as singletons in 3+1 dimensions are explicitly invariant under the infinite-dimensional higher-spin gauge symmetries. Conventional anyonic and gravitational interactions of massless fields correspond to appropriate finite-dimensional subalgebras of the higher-spin superalgebras.
A NOTE ON 2D CHIRAL GRAVITY AND CHIRAL BOSONS
Authors: BASTIANELLI FIORENZO
Published: November 2004

Quantization of two-dimensional chiral matter coupled to gravity induces an effective action for the zweibein field which is both Weyl and Lorentz anomalous. Recently, the quantization of this induced action has been analyzed in the light-cone gauge as well as in the conformal gauge. An apparent mismatch between the results obtained in the two gauges is analyzed and resolved by properly treating the Lorentz field as a chiral boson.
TRANSPARENCY OF DOMAIN WALLS TO ELECTROMAGNETIC AND NEUTRINO WAVES: AN EXACT SOLUTION
Authors: WANG ANZHONG
Published: November 2004

An exact solution of the Einstein-Maxwell-Weyl equations is given, which represents a planar domain wall accompanied by electromagnetic and neutrino waves. It is found that the wall is entirely transparent to these two pure radiation fields, and that the evolution of the wall is not affected by the presence of them.
NUCLEAR MULTIFRAGMENTATION AND INTERMITTENCY
Authors: SINGH G. , JAIN P. L. , EL-NAGDY M. S.
Published: November 2004

The charge distribution of nuclear fragments for events of 131 Xe at 1.22A GeV in nuclear emulsion is fitted with a power law. Method of scaled factorial moments is used to study fluctuations in the nuclear fragmentations. An intermittent behavior is found in the data but no convincing evidence of critical phenomenon is observed in nuclear fragmentation.
GRADED LIE ALGEBRA AND GENERALIZED CHERN-SIMONS ACTIONS IN ARBITRARY DIMENSIONS
Authors: KAWAMOTO NOBORU , WATABIKI YOSHIYUKI
Published: November 2004

We obtain generalized Chern-Simons actions in arbitrary dimensions. A graded Lie algebra plays an essential role in extending into odd dimensions in contrast with the even-dimensional generalized Chern-Simons action which we have obtained previously. As a particular example we obtain three-dimensional generalized Chern-Simons action which includes the standard Chern-Simons action together with additional terms which are responsible for a new type of gauge symmetry as well as supersymmetry. As a particular supersymmetric version, we obtain an action whose partition function is Casson invariant. We also find series of gauge invariant physical observables.
THE EVIDENCE FOR A 17 keV NEUTRINO REVISITED
Authors: CLINE DAVID B. , HONG WOOPYO
Published: November 2004

We review the evidence for a 17 keV neutrino obtained in some recent experiments from a distortion of the β decay spectrum near the end point for various nuclei. We also indicate the experiments that have failed to observe this signal and contrast the two results. A number of questions are posed for both types of experiments and we show that the presence of unexpected non-Gaussian errors could simulate a signal in some experiments.
ELASTIC SCATTERING WITH THE LIPATOV POMERON
Authors: CONTOGOURIS A. P. , LEBESSIS F.
Published: November 2004

First a unitarization procedure for an amplitude with the asymptotic behavior of the Lipatov Pomeron is presented; it amounts to its iteration along the s-channel. Next, based on this procedure, a specific model is considered and applied to the description of elastic scattering data at very high energies; it is shown that it leads to a fair description of them.
ON QUANTUM MECHANICS ON COMPACT SPACE
Authors: OHNUKI Y. , KITAKADO S.
Published: November 2004

Non-relativistic quantum mechanics is formulated on the surface of a four-dimensional sphere (S3). It is shown that a point particle on S3 can automatically carry spin.
THE OPERATOR ALGEBRA OF THE DISCRETE STATE OPERATORS IN 2D GRAVITY WITH NON-VANISHING COSMOLOGICAL CONSTANT
Authors: DOTSENKO Vl. S.
Published: November 2004

Remarks are given to the structure of physical states in the 2D gravity coupled to C≤1 matter. The operator algebra of the discrete state operators is calculated for the theory with non-vanishing cosmological constant.
EQUIVALENCE OF MASSIVE PROPAGATOR DISTANCE AND MATHEMATICAL DISTANCE ON GRAPHS
Authors: FILK THOMAS
Published: November 2004

It is shown that the assignment of distance according to the massive propagator method and according to the mathematical definition (length of minimal path) on arbitrary graphs with a bound on the degree leads to equivalent large scale properties of the graph. Especially, the internal scaling dimension is the same for both definitions. This result holds for any fixed, non-vanishing mass, so that a really inequivalent definition of distance requires the limit m→0.
TOPOLOGICAL LATTICE MODELS IN FOUR DIMENSIONS
Authors: OOGURI HIROSI
Published: November 2004

We define a lattice statistical model on a triangulated manifold in four dimensions associated to a group G. When G= SU (2), the statistical weight is constructed from the 15j-symbol as well as the 6j-symbol for recombination of angular momenta, and the model may be regarded as the four-dimensional version of the Ponzano-Regge model. We show that the partition function of the model is invariant under the Alexander moves of the simplicial complex, thus it depends only on the piecewise linear topology of the manifold. For an orientable manifold, the model is related to the so-called BF model. The q-analog of the model is also constructed, and it is argued that its partition function is invariant under the Alexander moves. It is discussed how to realize the 't Hooft operator in these models associated to a closed surface in four dimensions as well as the Wilson operator associated to a closed loop. Correlation functions of these operators in the q-deformed version of the model would define a new type of invariants of knots and links in four dimensions.
δ2-QUANTIZATION OF GAUGE FIELDS
Authors: SISSAKIAN A. N. , SOLOVTSOV I. L. , Yu. SHEVCHENKO O.
Published: November 2004

On the basis of the path-integral formalism in the phase space, a new scheme of quantization of gauge fields is proposed. The path integral in the configuration space is shown to contain two functional δ-functions that reflect the gauge condition and the Gauss law. A new propagator is obtained for the vector field which, for instance, for gauges nμAμ=0 distinguishes choices between time- and space-like vectors nμ and does not lead to contradictions in the computation of the Wilson loop.