bluuebunny/crossref_metadata_2025 huggingface dataset:
THERMAL SQUEEZING AND DENSITY FLUCTUATIONS IN SEMICLASSICAL THEORY OF GRAVITY
Authors: SURESH P. K.
Published: May 2003

A thermal squeezed state representation is constructed for each mode of a quantized scalar field in a spatially homogeneous and flat Robertson–Walker metric and the validity of semiclassical Einstein equation by analyzing the density fluctuation is examined. The density fluctuation in thermal squeezed state is very large and therefore the semiclassical theory may not be valid for squeezing parameter more than unity, however the theory holds when the associated squeezing parameter is much less than the unity. Further noted that the semiclassical theory is consistent in thermal coherent state formalism. The present study can account for the density fluctuations due to the thermal and quantum effects in semiclassical theory of gravity.
THE ENERGY OF 5D SOLITONS
Authors: SAJKO W. N. , WESSON P. S.
Published: May 2003

We clarify the status of 5D solitons by calculating their energies using a Hamiltonian approach. These objects in general possess gravitational, scalar and electromagnetic energy which complicates their space–time structure. However, the Schwarzschild case is unique in having an event horizon that gives back the usual 4D entropy. We outline applications to grand-unified theories and tests of the equivalence principle.
ON THE MIXED SYMMETRY IRREDUCIBLE REPRESENTATIONS OF THE POINCARÉ GROUP IN THE BRST APPROACH
Authors: BURDÍK ČESTMÍR , PASHNEV A. , TSULAIA M.
Published: May 2003

The Lagrangian description of irreducible massless representations of the Poincaré group with the corresponding Young tableaux having two rows along with some explicit examples including the notoph and Weyl tensor is given. For this purpose the method of the BRST constructions is adopted to the systems of second-class constraints by the construction of an auxiliary representations of the algebras of constraints in terms of Verma modules.
SOME ALGEBRAIC SYMMETRIES OF (2, 2)-SUPERSYMMETRIC SYSTEMS
Authors: HÜBSCH TRISTAN
Published: May 2003

The Hilbert spaces of supersymmetric systems admit symmetries which are often related to the topology and geometry of the (target) field-space. Here, we study certain (2, 2)-supersymmetric systems in two-dimensional space–time which are closely related to superstring models. They all turn out to possess some hitherto unexploited and geometrically and topologically unobstructed symmetries, providing new tools for studying the topology and geometry of superstring target space–times, and so the dynamics of the effective field theory in these.
REAL KM MATRIX AND CABIBBO MATRIX
Authors: CVAVB CHANDRARAJU
Published: May 2003

Fritzsch type of real symmetric 3×3 matrices are chosen. From these matrices the mass matrices relevant to the four-quark cases are deduced. It is also shown that the orthogonal matrices that diagonalize the 3×3 Fritzsch mass matrices also yield the orthogonal matrices that diagonalize the mass matrices corresponding to the four-quark case. The Cabibbo mixing matrix is straightaway obtained from the KM real mixing matrix. An exact expression for the Cabibbo mixing angle is found here. The real KM matrix is reduced to a few parameters, which can be determined from the experiment. The results obtained here are the exact expressions for the KM real matrix.
COMPOSITE OPERATORS AND TOPOLOGICAL CONTRIBUTIONS IN GAUGE THEORY
Authors: LEE JUNGJAI , HAN YEONG DEOK
Published: May 2003

In D-dimensional gauge theory with a kinetic term based on p-form tensor gauge field, we introduce a gauge-invariant operator associated with the composite form from an electric (p - 1)-brane and a magnetic (q - 1)-brane in D = p + q + 1 space–time dimensions. By evaluating the partition function of this operator, we show that the expectation value of this operator gives rise to the topological contributions identical to those in gauge theory with a topological Chern–Simons BF term.
STUECKELBERG MASS IN THE GLASHOW–WEINBERG–SALAM MODEL
Authors: KUZMIN S. V. , McKEON D. G. C.
Published: May 2003

The consequences of including a Stueckelberg mass term for the U(1) gauge field in the standard SU (2) × U (1) model of electroweak interactions is examined. This is consistent with both unitarity and renormalizability as it is demonstrated that the same arguments for these properties apply as in the case in which this term is absent. However, no massless "photon" occurs and all vector couplings break parity when this term is present.
ENTROPY OF SCHWARZSCHILD–de SITTER BLACK HOLE IN NON-THERMAL-EQUILIBRIUM
Authors: ZHAO REN , ZHANG JUNFANG , ZHANG LICHUN
Published: May 2003

Starting from the Klein–Gordon equation, we calculate the entropy of Schwarzschild–de Sitter black hole in non-thermal-equilibrium by using the improved brick-wall method-membrane model. When taking the proper cutoff in the obtained result, we obtain that both black hole's entropy and cosmic entropy are proportional to the areas of event horizon. We avoid the logarithmic term and stripped term in the original brick-wall method. It offers a new way of studying the entropy of the black hole in non-thermal-equilibrium.
THE EFFECTS OF A GENERALIZED COSMOLOGICAL CONSTANT ON THE PRIMORDIAL 4He ABUNDANCE
Authors: AL-RAWAF A. S.
Published: May 2003

In a previous work we showed that the introduction of a cosmological constant of the form [Formula: see text] provides more room for consistency with the recent observational data on Hubble's constant and the age of the universe. In this letter, we study the effect of the model on primordial 4He abundance and find that the model leads only to a slight increase in 4 He .
INDEPENDENT-NUCLEON INTERACTIONS IN COLLISIONS OF 4.2A GeV/c CARBON IONS WITH EMULSION NUCLEI
Authors: EL-NAGDY M. S.
Published: May 2003

The average values and dispersion of produced shower particles in 12 C interactions with emulsion at 4.2A GeV/c are discussed in the framework of the independent-nucleon interaction model. Support for this hypothesis is obtained. The probability for one up to 12 nucleons from the incident carbon to interact with the target nucleus is determined. The results can be interpreted in view of the Berkeley data using 12 C fragmentation in an inclusive experiment.
CHROMATICITY EFFECTS IN MICROLENSING BY WORMHOLES
Authors: EIROA ERNESTO , ROMERO GUSTAVO E. , TORRES DIEGO F.
Published: May 2003

Chromaticity effects introduced by the finite source size in microlensing events by presumed natural wormholes are studied. It is shown that these effects provide a specific signature that allow to discriminate between ordinary and negative mass lenses through the spectral analysis of the microlensing events. Both galactic and extragalactic situations are discussed.
SOLUTIONS TO COSMOLOGICAL PROBLEMS WITH ENERGY CONSERVATION AND VARYING c, G AND Λ
Authors: GOPAKUMAR P. , VIJAYAGOVINDAN G. V.
Published: May 2003

The flatness and cosmological constant problems are solved with varying speed of light c, gravitational coupling strength G and cosmological parameter Λ, by explicitly assuming energy conservation of observed matter. The present solution to the flatness problem is the same as a previous solution in which energy conservation was absent.
PROSPECTS OF DISCOVERING THE HIGGS BOSON AT THE TEVATRON
Authors: AGRAWAL PANKAJ
Published: May 2003

We carry out an event generator based study to evaluate the usefulness of the exclusive signature "e±(μ±) + 2 bottom jets" in discovering the Higgs boson at the Tevatron. Using an event generator, we show that with enough luminosity, one should be able to detect the Higgs boson up to the mass of about 130 GeV. We consider a slightly modified version of the above signature that includes one extra jet. This new signature is more useful because it increases the number of signal events significantly.
SLOW PARTICLE PRODUCTION IN THE INTERACTIONS OF 200 A GeV SULPHUR PROJECTILE WITH NUCLEAR EMULSION
Authors: DHAMIJA S. , AGGARWAL M. M. , BHATIA V. S.
Published: May 2003

We report our experimental results on various constituents of grey particles (0.23< β < 0.7), namely pions, kaons, and baryons, emitted in Sulphur-Emulsion interactions at 200 A GeV energy. These particles have been identified with good resolution and their emission angles have also been measured. Comparison has been made with similar data from proton-Em interactions and with predictions from the Modified FRITIOF Code (MFC). We find that the pion production is higher in the case of S-Em interactions as compared to that in p-Em interactions. MFC gives pions in agreement with our experimental value but underpredicts the kaon yield. The angular distribution is related to the amount of rescattering taking place in the target spectator region. The value of rescattering parameter, κ, as deduced from our data, has been found to be significantly smaller in case of pions as compared to that of kaons and baryons. This indicates that pion production involves a greater degree of rescattering of participants, during the collision process, as compared to kaons and baryons. The values of κ for all the three grey particle constituents, as calculated from the Modified FRITIOF Code, are higher than the experimental values. This suggests that there is a need to incorporate a greater degree of rescattering in the model.
HER X-1: A QUARK–DIQUARK STAR?
Authors: SHARMA R. , MUKHERJEE S.
Published: May 2003

Using a general solution to the Vaidya–Tikekar model for a spherically symmetric superdense star, we show that the equation of state (EOS) of a star with values of mass and radius within the experimental ranges for Her X-1 (a compact X-ray binary pulsar), agrees accurately with the EOS obtained by Horvath et al.,1 who considered a quark–diquark mixture in equilibrium. Nevertheless, we note that the boundary condition chosen for bosonic (diquark) component in Ref. 1 is not appropriate and the identification of Her X-1 as a quark–diquark star remains inconclusive.
RESOLUTION OF UNITY IN DIFFERENTIAL FORM FOR EPR COMPLEX ENTANGLED STATE REPRESENTATION AND ITS APPLICATION IN NONLINEAR OPERATORS' NORMAL ORDERING EXPANSION
Authors: FAN HONGYI , YU GUICHUAN
Published: May 2003

We find that the resolution of unity for the EPR (Einstein, Podolsky and Rosen) entangled state representation can be in differential form. Its application in studying normally ordered expansion of some complicated exponential operators is demonstrated.
TOPOLOGICAL STRUCTURE OF ENTROPY OF (3+1)-DIMENSIONAL SPHERICALLY SYMMETRIC BLACK HOLES
Authors: YANG GUO-HONG
Published: May 2003

Using the relationship between the entropy and the Euler characteristic, an entropy density is introduced to describe the inner topological structure of the entropy of (3+1)-dimensional spherically symmetric black holes. It is pointed out that the density of entropy is determined by the singularities of the timelike Killing vector field of space–time, and these singularities carry the topological numbers, Hopf indices and Brouwer degrees, naturally, which are topological invariants. Taking account of the physical meaning in statistics, the entropy of black holes is given by the Hopf indices merely, which will lead to the increasing principle of entropy of black holes.
COSMOLOGY OF DILATONIC BRANE WORLD
Authors: YOUM DONAM
Published: May 2003

We study cosmological solutions in the dilatonic brane world models. The effective four-dimensional equations on the brane are analyzed for the models with one positive tension brane and two branes with tensions of opposite signs. Just as in the non-dilatonic brane case, the conventional Friedmann equations of the four-dimensional universe are reproduced to the leading order in matter energy density for the model with one brane and the introduction of a radion potential is required in order to reproduce the Friedmann equations with the correct sign for the model with two branes.
THE ROBUSTNESS OF INFLATION TO CHANGES IN SUPER-PLANCK-SCALE PHYSICS
Authors: BRANDENBERGER ROBERT H. , MARTIN JÉRÔME
Published: May 2003

We calculate the spectrum of density fluctuations in models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, and specifically investigate the dependence of the predictions on modifications of the physics on length scales smaller than the Planck length. These modifications are encoded in terms of modified dispersion relations. Whereas for some classes of dispersion relations the predictions are unchanged compared to the usual ones which are based on a linear dispersion relation, for other classes important differences are obtained, involving tilted spectra, spectra with exponential factors and with oscillations. This is the case when the dispersion relation becomes complex. We conclude that the predictions of inflationary cosmology in these models are not robust against changes in the super-Planck-scale physics.
SPECTRUM OF THE LOOP TRANSFER MATRIX ON FINITE LATTICES
Authors: DASKALAKIS GEORGIOS , SAVVIDY GEORGE K.
Published: May 2003

We consider a model of random surfaces with extrinsic curvature term embedded into 3-D Euclidean lattice Z3. On a 3-D Euclidean lattice it has an equivalent representation in terms of the transfer matrix K(Qi, Qf), which describes the propagation of the loops Q. We study the spectrum of the transfer matrix K(Qi, Qf) on finite-dimensional lattices. The renormalisation group technique is used to investigate the phase structure of the model and its critical behaviour.
NONLINEAR GRAVITON AND THE PROBLEM OF MASS GENERATION
Authors: MAGNON ANNE
Published: May 2003

We argue that the massless mediator of a long range interaction can acquire mass through collision with a nonlinear graviton. The process displays analogy with the Higgs mechanism, and compensates for a broken mirror symmetry (duality), at the past–future bifurcation. Mass is formulated as the electric charge of a suitable state emerging from the particle–antiparticle (self–antiself dual) confrontation. Such considerations suggest that the experimental quest of the Higgs boson could in fact shed light on the (so far theoretical) quantum gravity programme.
ANTISYMMETRIC TENSOR FIELDS IN THE LOCALLY LOCALIZED GRAVITY MODELS
Authors: ODA ICHIRO
Published: May 2003

We study the localization property of antisymmetric tensor fields in the locally localized gravity models. It is shown that all the antisymmetric tensor fields, including the vector field, in a bulk space–time are trapped on an AdS brane by a gravitational interaction where the presence of the brane cosmological constant plays an important role as in the cases of other bulk fields. The normalized zero-modes spread rather widely in extra space, so small extra dimensions might be needed in order not to conflict with experiment.
ALMOST CLASSICAL CREATION OF A UNIVERSE
Authors: GUENDELMAN E. I. , PORTNOY J.
Published: May 2003

We study the problem of a 1 + 1 cord with a dynamical massless scalar field living in it, which separates a false vacuum and a conical region in a 2 + 1 space. A stable "particle-like" configuration can be found. Also, oscillating solutions exist which can tunnel to an expanding type solution. The most outstanding feature for these oscillating solution is that we do not need a singularity to create an infinite universe from them, and that an arbitrarily small tunneling is needed to achieve this. Possible consequences for similar processes, involving cosmic strings in 3 + 1 dimensions are discussed.
REMARKS ON SOME QUANTUM EFFECTS IN A GLOBAL MONOPOLE SPACE–TIME
Authors: DE A. MARQUES GEUSA , BEZERRA VALDIR B.
Published: May 2003

We study the behaviour of a nonrelativistic quantum particle interacting with the Kratzer molecular potential in the space–time of a global monopole. We find the energy spectrum and derive the scattering amplitude of massive particles propagating in these fields and show how they differ from their free-space values.
SELF-TUNING DARK ENERGY IN BRANE WORLD COSMOLOGY
Authors: UZAWA KUNIHITO , SODA JIRO
Published: May 2003

In this letter, the self-tuning mechanism of dark energy is proposed by considering the cosmological matter in the brane world. In the first part of this letter, the effective four-dimensional Friedmann equation in the presence of the bulk scalar field is derived. In our model, the bulk scalar field takes the role of the dark energy and its value is slowly varying in time. The claim is that, even if the enormous amount of vacuum energy exists on the brane, the present value of the dark energy is self-tuned to be consistent with the current observations. This result will open the possibility to discuss the dark energy in the brane world in the context of the anthropic principle or quantum cosmology.
IMPACT OF AHARONOV–BOHM SOLENOID ON PARTICLE RADIATION IN MAGNETIC FIELD
Authors: BAGROV V. G. , GITMAN D. M. , LEVIN A. D. , TLYACHEV V. B.
Published: May 2003

We study the impact of Aharonov–Bohm solenoid on the radiation of a charged particle moving in a constant uniform magnetic field. Radiation peculiarities caused by the presence of the solenoid may be considered as a manifestation of Aharonov–Bohm effect in the radiation. In particular, new spectral lines appear in the radiation spectrum. Due to angular distribution peculiarities of the radiation intensity, these lines can in principle be isolated from basic cyclotron and synchrotron radiation spectra.
ARE NEUTRAL GOLDSTONE BOSONS INITIATING VERY ENERGETIC AIR SHOWERS AND ANOMALOUS MULTIPLE-CORE STRUCTURE AS A COMPONENT OF COSMIC RAYS?
Authors: BARSHAY SAUL , KREYERHOFF GEORG
Published: May 2003

We consider two recently accentuated, unusual empirical results concerning cosmic-ray events at high energies. We show that the possibility for a correlated explanation is provided by new dynamics which arises from collisions of a neutral Goldstone boson as a component of the highest-energy cosmic rays.
PARTICLE CREATION IN AN OSCILLATING SPHERICAL CAVITY
Authors: SETARE M. R. , SAHARIAN A. A.
Published: May 2003

We study the creation of massless scalar particles from the quantum vacuum due to the dynamical Casimir effect by spherical shell with oscillating radius. In the case of a small amplitude of the oscillation, to solve the infinite set of coupled differential equations for the instantaneous basis expansion coefficients we use the method based on the time-dependent perturbation theory of the quantum mechanics. To the first order of the amplitude we derive the expressions for the number of the created particles for both parametric resonance and non-resonance cases.
NONLOCAL REGULARIZATION OF ABELIAN MODELS WITH SPONTANEOUS SYMMETRY BREAKING
Authors: CLAYTON M. A.
Published: May 2003

We demonstrate how nonlocal regularization is applied to gauge-invariant models with spontaneous symmetry breaking. Motivated by the ability to find a nonlocal BRST invariance that leads to the decoupling of longitudinal gauge bosons from physical amplitudes, we show that the original formulation of the method leads to a nontrivial relationship between the nonlocal form factors that can appear in the model.
SUPERCONDUCTING PHASE TRANSITION IN THE NAMBU–JONA-LASINIO MODEL
Authors: SADZIKOWSKI M.
Published: May 2003

The Nambu–Bogoliubov–de Gennes method is applied to the problem of superconducting QCD. The effective quark–quark interaction is described within the framework of the Nambu–Jona-Lasinio model. The details of the phase diagram are given as a function of the strength of the quark–quark coupling constant G′. It is found that there is no superconducting phase transition when one uses the relation between the coupling constants G′ and G of the Nambu–Jona-Lasinio model which follows from the Fierz transformation. However, for other values of G′ one can find a rich phase structure containing both the chiral and the superconducting phase transitions.
OPERATOR QUANTIZATION OF CONSTRAINED WZNW THEORIES AND COSET CONSTRUCTIONS
Authors: BRATCHIKOV A. V.
Published: May 2003

Using two WZNW theories for Lie algebras g and h, h ⊂ g, we construct the associative quotient algebra which includes a class of g/h coset primary fields and currents.
COMMENTS ON BRANE WORLD COSMOLOGY
Authors: ANCHORDOQUI LUIS , OLSEN KASPER
Published: May 2003

In this letter we consider some constraints on brane-world cosmologies. In the first part we analyze different behaviors for the expansion of our universe by imposing constraints on the speed of sound. In the second part, we study the nature of matter on the brane world by means of the well-known energy conditions. We find that the strong energy condition must be completely violated at late stages of the universe.
ANGULAR QUANTIZATION AND THE DENSITY MATRIX RENORMALIZATION GROUP
Authors: GAITE J.
Published: May 2003

Path integral techniques for the density matrix of a one-dimensional statistical system near a boundary previously employed in black-hole physics are applied to provide a new interpretation of the density matrix renormalization group: Its efficacy is due to the concentration of quantum states near the boundary.
GLOBAL MONOPOLES AND SCALAR FIELDS AS THE ELECTROGRAVITY DUAL OF SCHWARZSCHILD SPACE–TIME
Authors: DADHICH NARESH , BANERJEE NARAYAN
Published: May 2003

We prove that both global monopole and minimally coupled static zero mass scalar field are electrogravity dual of the Schwarzschild solution or flat space and they share the same equation of state, [Formula: see text]. This property was however known for the global monopole space–time while it is for the first time being established for the scalar field. In particular, it turns out that the Xanthopoulos–Zannias scalar field solution is dual to flat space.
ON THE DETECTION OF SCALAR HAIR
Authors: BANERJEE NARAYAN , SEN SOMASRI , DADHICH NARESH
Published: May 2003

It is shown that the conclusion regarding the existence of a scalar hair for a black hole in a non-minimally coupled self-interacting scalar–tensor theory can be drawn from that for a scalar field minimally coupled to gravity by means of a conformal transformation.
EXPECTATION VALUES OF BOUNDARY FIELDS IN INTEGRABLE BOUNDARY TODA THEORIES
Authors: FATEEV V. A.
Published: May 2003

Integrable boundary Toda theories are considered. We derive boundary reflection amplitudes and boundary two-point functions in the non-affine and one-point functions in affine Toda theories. The boundary ground state energies are conjectured.
QUANTUM FIELDS FOR WORMHOLES
Authors: MAITI A. K. , GUPTA NAYANTARA , BHATTACHARYYA D. P.
Published: May 2003

Following a suggestion of Hawking it is shown that wormholes can be realized in terms of some quantum fields rather than some parameters and Coleman's "big-fix" can also be understood in this case. These quantum fields should obey the Wheeler–de Witt equation in case they depend upon the induced metric of the wormholes. This opens a new area of studying wormhole physics as a field theory.
QUANTUM BOUNDS FOR GRAVITATIONAL DE SITTER ENTROPY AND THE CARDY–VERLINDE FORMULA
Authors: NOJIRI S. , OBREGON O. , ODINTSOV S. D. , QUEVEDO H. , RYAN M. P.
Published: May 2003

We analyze different types of quantum corrections to the Cardy–Verlinde entropy formula in a Friedmann–Robertson–Walker universe and in an (anti)-de Sitter space. In all cases we show that quantum corrections can be represented by an effective cosmological constant which is then used to redefine the parameters entering the Cardy–Verlinde formula so that it becomes valid also with quantum corrections, a fact that we interpret as a further indication of its universality. A proposed relation between Cardy–Verlinde formula and the ADM Hamiltonian constraint is given.
SOLUTION OF THE KLEIN–GORDON EQUATION IN A 2 + 1 CURVED SPACE–TIME
Authors: HARRIOTT TINA A. , WILLIAMS J. G.
Published: May 2003

The Klein–Gordon equation for a massless scalar field is considered for an extended matter source in 2 + 1 dimensions. It is shown how a solution can be found using Whittaker functions and can be normalized in the standard manner. In the point source limit, the solution reduces to the usual expression in terms of Bessel functions.
LOCAL OBSERVED TIME AND REDSHIFT IN CURVED SPACE–TIME
Authors: FENG SZE-SHIANG
Published: May 2003

Using the observed time and spatial intervals defined originally by Einstein and the observational frame in the vierbein formalism, we propose that in curved space–time, for a wave received in laboratories, the observed frequency is the changing rate of the phase of the wave relative to the local observable time scale and the momentum is the changing rate of the phase relative to the local observable spatial length scale. The case of Robertson–Walker universe is especially considered and the application to de Sitter universe results in a cosmological constant in perfect agreement with the observational data.
SELF-EXISTING OBJECTS AND AUTO-GENERATED INFORMATION IN CHRONOLOGY-VIOLATING SPACE–TIMES: A PHILOSOPHICAL DISCUSSION
Authors: ROMERO GUSTAVO E. , TORRES DIEGO F.
Published: May 2003

Closed time-like curves (CTCs) naturally appear in a variety of chronology-violating space–times. In these space–times, the principle of self-consistency demands a harmony between local and global affairs that excludes grandfather-like paradoxes. However, self-existing objects trapped in CTCs are not seemingly avoided by the standard interpretation of this principle, usually constrained to a dynamical framework. In this letter we discuss whether we are committed to accept an ontology with self-existing objects if CTCs actually occur in the universe. In addition, the epistemological status of the principle of self-consistency is analyzed and a discussion on the information flux through CTCs is presented.
A NOVEL SPIN-STATISTICS THEOREM IN (2 + 1)DCHERN–SIMONS GRAVITY
Authors: BALACHANDRAN A. P. , BATISTA E. , COSTA E SILVA I. P. , TEOTONIO-SOBRINHO P.
Published: May 2003

It has been known for some time that topological geons in quantum gravity may lead to a complete violation of the canonical spin-statistics relation: There may be no connection between spin and statistics for a pair of geons. We present an algebraic description of quantum gravity in a (2 + 1) D manifold of the form Σ × ℝ, based on the first-order canonical formalism of general relativity. We identify a certain algebra describing the system, and obtain its irreducible representations. We then show that although the usual spin-statistics theorem is not valid, statistics is completely determined by spin for each of these irreducible representations, provided one of the labels of these representations, which we call flux, is superselected. We argue that this is indeed the case. Hence, a new spin-statistics theorem can be formulated.
BASIC PROPERTIES OF COHERENT AND GENERALIZED COHERENT OPERATORS REVISITED
Authors: FUJII KAZUYUKI
Published: May 2003

In this paper we make a brief review of some basic properties (the matrix elements, the trace, the Glauber formula) of coherent operators and study the corresponding ones for generalized coherent operators based on Lie algebra su(1,1). We also propose some problems.
TOPOLOGICAL DEFECTS AND GRAVITATIONAL FORCES IN BRANS–DICKE THEORY
Authors: BARROS A. , ROMERO C.
Published: May 2003

The nature of gravitational forces exerted by topological defects on surrounding matter in the frame of Brans–Dicke theory of gravity (BD) is investigated. Comparison is made with the corresponding cases in General Relativity (GR). The role of the scalar field as a weakener agent of the strength of gravitational forces due to pressure terms is discussed.
THE CARDY–VERLINDE FORMULA AND ASYMPTOTICALLY FLAT CHARGED BLACK HOLES
Authors: YOUM DONAM
Published: May 2003

We show that the modified Cardy–Verlinde formula without the Casimir effect term is satisfied by asymptotically flat charged black holes in arbitrary dimensions. Thermodynamic quantities of the charged black holes are shown to satisfy the energy-temperature relation of a two-dimensional CFT, which supports the claim in our previous work (Phys. Rev.D61, 044013, hep-th/9910244) that thermodynamics of charged black holes in higher dimensions can be effectively described by two-dimensional theories. We also check the Cardy formula for the two-dimensional black hole compactified from a dilatonic charged black hole in higher dimensions.
RESONANCE PROPAGATION AND THRESHOLD SINGULARITIES
Authors: LUCIO J. L. M. , PESTIEAU J.
Published: May 2003

We consider the problem of propagation in the framework of quantum field theory in relation to the mass and width definition for an unstable particle. Using unitarity, we show that a renormalization constant free of threshold singularities naturally arises.
DIRAC SPINOR IN BIANCHI-I UNIVERSE WITH TIME-DEPENDENT GRAVITATIONAL AND COSMOLOGICAL CONSTANTS
Authors: SAHA BIJAN
Published: May 2003

Self-consistent system of nonlinear spinor field and Bianchi I (BI) gravitational one with time-dependent gravitational constant (G) and cosmological constant (Λ) has been studied. The initial and the asymptotic behaviors of the field functions and the metric one have been thoroughly investigated. Given Λ = Λ0/τ2, with [Formula: see text], G has been estimated as a function of τ. The role of perfect fluid at the initial state of expansion and asymptotical isotropization process of the initially anisotropic universe has been elucidated.
ON THE CONSTRUCTION OF SHEARFREE COSMOLOGICAL MODELS
Authors: CHROBOK T. , OBUKHOV Y. N. , SCHERFNER M.
Published: May 2003

Using the proper time description and the usual cosmological observer field, it is possible to construct general space–time metrics representing a class of shearfree cosmological models.
OFF-SHELL EFFECTIVE LAGRANGIAN FOR NRQCD AND HEAVY QUARKS EFFECTIVE THEORY
Authors: GAMBOA J. , LEPE S. , VERGARA L.
Published: May 2003

A derivation of the effective Lagrangian for non-relativistic quantum chromodynamics and the heavy quarks effective field theory is given. Our calculation provides a simple and systematic method of calculation of the full off-shell effective Lagrangian at tree level including all the 1/m corrections.
INEVITABILITY OF SPACE–TIME SINGULARITIES IN THE CANONICAL METRIC
Authors: PONCE DE LEON J.
Published: May 2003

We discuss the question of whether the existence of singularities is an intrinsic property of 4D space–time. Our hypothesis is that singularities in 4D are induced by the separation of space–time from the other dimensions. We examine this hypothesis in the context of the so-called canonical or warp metrics in 5D. These metrics are popular because they provide a clean separation between the extra dimension and space–time. We show that the space–time section, in these metrics, inevitably becomes singular for some finite (nonzero) value of the extra coordinate. This is true for all canonical metrics that are solutions of the field equations in space–time-matter theory. This is a coordinate singularity in 5D, but appears as a physical one in 4D. At this singular hypersurface, the determinant of the space–time metric becomes zero and the curvature of the space–time blows up to infinity. These results are consistent with our hypothesis.
BRST INVARIANT CP1 MODEL THROUGH IMPROVED DIRAC QUANTIZATION
Authors: HONG SOON-TAE , PARK YOUNG-JAI , KUBODERA KUNIHARU , MYHRER FRED
Published: May 2003

The Batalin–Fradkin–Tyutin (BFT) scheme, which is an improved version of Dirac quantization, is applied to the CP1 model, and the compact form of a nontrivial first-class Hamiltonian is directly obtained by introducing the BFT physical fields. We also derive a BRST-invariant gauge fixed Lagrangian through the standard path-integral procedure. Furthermore, performing collective coordinate quantization we obtain energy spectrum of rigid rotator in the CP1 model. Exploiting the Hopf bundle, we also show that the CP1 model is exactly equivalent to the O(3) nonlinear sigma model at the canonical level.
SPONTANEOUS TIME ASYMMETRY DUE TO HORIZON
Authors: ANISHETTY RAMESH , PARTHASARATHY R.
Published: May 2003

We show that quantized matter fields in the presence of background metrics with horizon exhibit spontaneous time asymmetry. Some phenomenological applications of this in the context of black holes and early universe are considered.
THERMODYNAMICS OF de SITTER SPACE–TIME IN YORK'S FORMALISM
Authors: WANG BO-BO , HUANG CHAO-GUANG
Published: May 2003

The York's formalism of path-integral approach to the thermodynamics of black holes is applied to de Sitter space–time. The first law of thermodynamics for de Sitter space–time is given, which includes a "work term" with respect to the cosmological constant.
S-MATRICES FOR QUANTUM CHARGED MASSIVE SCALAR PARTICLES ON KERR BLACK HOLES
Authors: FIRSOVA N. E.
Published: May 2003

The results obtained recently on the scattering problems connected with the contribution of the topologically inequivalent configurations of the massless complex scalar field on Kerr black holes to the Hawking radiation are extended to include the massive case as well. The corresponding S-matrices are examined and presented in the form convenient for numerical computations.
TESTABLE SIGNALS OF CHARM DECAY IN THE Bc-MESON
Authors: CHOUDHURY DEBAJYOTI , KUNDU ANIRBAN , MUKHOPADHYAYA BISWARUP
Published: May 2003

The b and c quarks compete with each other in the decays of the Bc-meson. We show how one can obtain reliable signals of c→s decay in the Bc system in order to calculate the relative strengths of the two types of decays. This, we argue, can be done by considering the decay [Formula: see text], followed by semileptonic decays of the Bs. We suggest looking for like-sign dileptons together with a Ds at the BTeV or LHC-B experiments, and show that such signals can be made background-free by suitable event selection.
VACUUM POLARIZATION IN THE SPACE–TIME OF A SCALAR–TENSOR COSMIC STRING
Authors: BEZERRA V. B. , FILHO R. M. TEIXEIRA , GREBOT G. , GUIMARÃES M. E. X.
Published: May 2003

We study the vacuum polarization effect in the space–time generated by a magnetic flux cosmic string in the framework of a scalar–tensor theory of gravity. The vacuum expectation values of the energy–momentum tensor of a conformally coupled scalar field are calculated and the dilaton's contribution to the vacuum polarization effect is shown.
ON THE ANTIPODE OF KREIMER'S HOPF ALGEBRA
Authors: FIGUEROA HÉCTOR , GRACIA-BONDÍA JOSÉ M.
Published: May 2003

We give a new formula for the antipode of the algebra of rooted trees, directly in terms of the bialgebra structure. The equivalence, proved in this paper, among the three available formulas for the antipode, reflects the equivalence among the Bogoliubov–Parasiuk–Hepp, Zimmermann, and Dyson–Salam renormalization schemes.
QUADRATIC GRAVITY IN (2+1)D
Authors: ACCIOLY ANTONIO , AZEREDO ABEL , MUKAI HATSUMI
Published: May 2003

Quadratic gravity in (2+1)D, unlike three-dimensional Einstein's gravity, is locally nontrivial and has an extremely well-behaved potential. Here we explore the gravitational properties of a metric generated by a pointlike matter distribution within the context of three-dimensional linearized quadratic gravity. This metric greatly resembles the four-dimensional metric of a straight U(1)-gauge cosmic string in the framework of linearized quadratic gravity. It is found that a gravitational force is exerted on a slowly moving test particle, a feature not present in general relativity in (2+1)D. It is also found that the massive scalar mode does not contribute anything to the gravitational deflection. An explanation for this fact is provided.
HIGGS MECHANISM WITH A TOPOLOGICAL TERM
Authors: ODA ICHIRO
Published: May 2003

In cases of both Abelian and non-Abelian gauge groups, we consider the Higgs mechanism in topologically massive gauge theories in an arbitrary space–time dimension. It is shown that the presence of a topological term makes it possible to shift mass of gauge fields in a nontrivial way compared to the conventional value at the classical tree level. We correct the previous misleading statement with respect to the counting of physical degrees of freedom, where it is shown that gauge fields become massive by "eating" the Nambu–Goldstone boson and a higher-rank tensor field, but a new massless scalar appears in the spectrum so the number of physical degrees of freedom remains unchanged before and after the spontaneous symmetry breakdown. Some related phenomenological implications and applications to superstring theory are briefly commented.
VACUUM SOLUTIONS IN HIGHER DIMENSIONS WITH BRANS–DICKE THEORY
Authors: CHAKRABORTY SUBENOY , BAVEJA ANUSUA
Published: May 2003

Vacuum solutions are obtained in higher-dimensional spherically symmetric space–time with Brans–Dicke theory. Solutions are obtained assuming the metric coefficients to be in separable product form.
AN ALTERNATIVE FORMULATION OF CLASSICAL ELECTROMAGNETIC DUALITY
Authors: LI KANG , NAÓN CARLOS M.
Published: May 2003

By introducing a doublet of electromagnetic four-dimensional vector potentials, we set up a manifestly Lorentz covariant and SO(2) duality invariant classical field theory of electric and magnetic charges. In our formulation one does not need to introduce the concept of Dirac string.
QED–QCD INTERFERENCE EFFECT ON THE CHARGE-DEPENDENT N–N INTERACTION
Authors: XU PU , WANG FAN , PING JIA-LUN , GOLDMAN T.
Published: May 2003

The charge symmetry breaking and charge independence breaking N–N1 S 0 scattering length differences, Δa CSB and Δa CIB , are calculated by a resonating group method with a quark cluster model. By adding the QED–QCD interference effect to the quark mass difference and the electromagnetic interaction, the Δa CSB and Δa CIB values can be reproduced with model parameters constrained by the hadron isomultiplet mass splitting.
RARE KAON DECAYS
Authors: GENG C. Q.
Published: May 2003

We study the rare kaon decays of [Formula: see text] and [Formula: see text]. In the standard mode, we find that the CP conserving and violating contributions to the branching ratios of [Formula: see text] are about 4.4 (1.0)× 10-13 and 1.0 (0.15)× 10-14, respectively.
ONE-LOOP EFFECTIVE POTENTIAL FOR SCALAR AND VECTOR FIELDS ON HIGHER-DIMENSIONAL NONCOMMUTATIVE FLAT MANIFOLDS
Authors: BYTSENKO A. A. , GONÇALVES A. E. , ZERBINI S.
Published: May 2003

The non-planar contribution to the effective potentials for massless scalar and vector quantum field theories on D-dimensional manifold with p compact noncommutative extra dimensions is evaluated by means of dimensional regularization implemented by zeta function techniques. It is found that, the zeta function associated with the one-loop operator may not be regular at the origin. Thus, the related heat kernel trace has a logarithmic term in the short t asymptotic expansion. Consequences of this fact are briefly discussed.
THERMODYNAMICAL QUANTITIES OF LATTICE FULL QCD FROM AN EFFICIENT METHOD
Authors: LUO XIANG-QIAN
Published: May 2003

We extend to QCD an efficient method for lattice gauge theory with dynamical fermions. Once the eigenvalues of the Dirac operator and the density of states of pure gluonic configurations at a set of plaquette energies (proportional to the gauge action) are computed, thermodynamical quantities deriving from the partition function can be obtained for arbitrary flavor number, quark masses and wide range of coupling constants, without additional computational cost. Results for the chiral condensate and gauge action are presented on the 104 lattice at flavor number Nf=0,1,2,3,4 and many quark masses and coupling constants. New results in the chiral limit for the gauge action and its correlation with the chiral condensate, which are useful for analyzing the QCD chiral phase structure, are also provided.
NON-EXISTENCE OF NEW QUANTUM ERGOSPHERE EFFECT OF A VAIDYA-TYPE BLACK HOLE
Authors: WU S. Q. , CAI X.
Published: May 2003

Hawking evaporation of Dirac particles and scalar fields in a Vaidya-type black hole is investigated by the method of generalized tortoise coordinate transformation. It is shown that Hawking radiation of Dirac particles does not exist for P1, Q2 components but for P2, Q1 components in any Vaidya-type black holes. Both the location and the temperature of the event horizon change with time. The thermal radiation spectrum of Dirac particles is the same as that of Klein–Gordon particles. We demonstrate that there is no new quantum ergosphere effect in the thermal radiation of Dirac particles in any spherically symmetry black holes.
COHOMOLOGY OF THE VARIATIONAL COMPLEX IN FIELD–ANTIFIELD BRST THEORY
Authors: SARDANASHVILY GENNADI
Published: May 2003

We show that cohomology of the variational complex in the field–antifield BRST theory on an arbitrary manifold X equals the de Rham cohomology of X. It follows that there is no topological obstruction to constructing global descent equations in BRST theory.
FAMILON EMISSION BY DENSE MAGNETIZED PLASMA
Authors: MIKHEEV N. V. , NARYNSKAYA E. N.
Published: May 2003

Emission of a familon caused by the processes e-→ e-+ϕ, e-→ μ-+ϕ in dense magnetized plasma is investigated in the model in which a familon has both direct and indirect coupling to leptons via plasmon. The process probabilities and the integral familon action on plasma are calculated. It is shown that the P odd interference phenomenon in the process e-→ μ-+ϕ leads to the familon force acting on plasma along the magnetic field.
COSMIC RAY MUON MEASUREMENT BY L3 SPECTROMETER AT CERN
Authors:   On behalf of the L3 Collaboration., MA YUQIAN
Published: May 2003

L3 + C is a branch experiment on L3 magnet spectrometer, which is located on the ring of LEP accelerator at CERN. To take the advantage of L3 muon chambers in its low threshold, wide dynamic range and high resolution, the momentum of cosmic ray muons in the range of 15–2000 GeV/c at a shallow depth of 30 m of molasse can be measured precisely. Since 1998, a scintillator detector system, a new fast trigger and DAQ system, and a small air shower array had been established for study the CR muon events independently. Up to August 2000, 8 billion muons and 25 million air shower events had been recorded. The first results for CR muon spectrum and the charge ratio etc. had been obtained.
GAUGE THEORY OF SECOND-CLASS CONSTRAINTS WITHOUT EXTRA VARIABLES
Authors: BATALIN IGOR , MARNELIUS ROBERT
Published: May 2003

We show that any theory with second-class constraints may be cast into a gauge theory if one makes use of solutions of the constraints expressed in terms of the coordinates of the original phase space. We perform a Lagrangian path integral quantization of the resulting gauge theory and show that the natural measure follows from a superfield formulation.
FROM BEVALAC TO AGS
Authors: FUNG SUN-YIU
Published: May 2003

We describe some research efforts and results in high energy nuclear physics experiments in which the University of California, Riverside Heavy Ion Physics Group was involved. The Group was formed in 1974 by the late Robert T. Poe and the author. The pre-RHIC research spanned an energy range from 1 GeV A at the BEVALAC in LBNL to 10 GeV A at the AGS in BNL.
LARGE MAGNETIC DIPOLE MOMENTS FOR NEUTRINOS WITH ARBITRARY NON-CALCULABLE MASSES
Authors: MONTERO J. C. , PLEITEZ V.
Published: May 2003

We show that there is a general sort of neutrino effective interactions which allows, under certain conditions, to have relatively large magnetic dipole moments for neutrinos while keeping their masses non-calculable and arbitrarily small. The main ingredient of our mechanism for generating large magnetic moment to the neutrinos is the existence of a neutral scalar which has the only role to give mass to the neutrinos or the existence of flavor changing neutral currents in the neutrino sector. Although our approach is model independent, some models in which those interactions arise are commented.
PHOTON-PAIR CONVERSION INTO NEUTRINOS IN A STRONG MAGNETIC FIELD
Authors: KUZNETSOV A. V. , MIKHEEV N. V.
Published: May 2003

A general analysis of the three-vertex loop amplitude in a strong magnetic field, based on the asymptotic form of the electron propagator in the field, is performed. In order to investigate the photon–neutrino process [Formula: see text], the vertex combinations of the scalar–vector–vector (SVV), pseudoscalar–vector–vector (PVV), three-vector (VVV), and axial-vector–vector–vector (AVV) types are considered. It is shown that only the SVV amplitude grows linearly with the magnetic field strength, while in the other amplitudes, PVV, VVV and AVV, the linearly growing terms are canceled. The process [Formula: see text] is investigated in the left–right-symmetric extension of the standard model of electroweak interaction, where the effective scalar νν e e coupling could exist. Possible astrophysical manifestations of the considered process are discussed.
WEAK RADIATIVE DECAY WIDTH OF Λb→Λγ DECAY
Authors: MAITI A. K. , KOLA S. , BHATTACHARYYA D. P.
Published: May 2003

We have systematically analyzed the two-body weak radiative Λb→Λγ decay of bottom baryon. The weak radiative decay proceeds through W-exchange accompanied by a photon emission. Effective Lagrangian has been used for the W-exchange bremsstrahlung processes to estimate the long distance effect through pole. The short distance effect at the quark level (b→sγ) is also estimated here. With these predictions we have finally obtained the branching ratio of Λb→Λγ as Br (Λb→Λγ)=2.3×10-10 which is in close agreement with the experimental results.
RADION POTENTIAL AND BRANE DYNAMICS
Authors: MERSINI L.
Published: May 2003

We examine the cosmology of Randall–Sundrum model in a dynamic setting where scalar fields are present in the bulk as well as the branes. This generates a mechanism similar to that of Goldberger–Wise for radion stabilization and the recovery of late-time cosmology features on the branes. Due to the induced radion dynamics, the inflating branes roll towards the minimum of the radion potential, thereby exiting inflation and reheating the universe. In the slow roll part of the potential, the TeV branes have maximum inflation rate and energy as their coupling to the radion and bulk modes have minimum suppression. Hence, when rolling down the steep end of the potential towards the stable point, the radion field (which appears as the inflaton of the effective 4-D theory in the branes) decays very fast and reheats the universe. This process results in a decrease of the brane's canonical vacuum energy, Λ4. However, at the minimum of the potential Λ4 is small but not necessarily zero and the fine-tuning issue remains. Density perturbation constraints introduce an upper bound on Λ4. Due to the large radion mass and strong suppression to the bulk modes, moduli problems and bulk reheating do not occur. The reheat temperature and a sufficient number of e-folding constraints for the brane-universe are also satisfied. The model therefore recovers the radiation dominated FRW universe.
2D GRAVITY WITHOUT TEST PARTICLES IS POINTLESS
Authors: GRUMILLER D. , HOFMANN D. , KUMMER W.
Published: May 2003

Claims of a general Weyl invariance of an arbitrary 2D dilaton theory are critically discussed.
RADIATIVE DECAY OF LIGHT AND HEAVY MESONS IN AN INDEPENDENT QUARK MODEL
Authors: ÇIFTCI HAKAN , KORU HÜSEYIN
Published: May 2003

In this paper we have calculated transition magnetic moments and radiative decay widths of light and heavy mesons using a relativistic potential model of independent quarks with its parameters determined from a fit to the mass of ground state mesons in the strange, charm and bottom flavor sectors. The results are in agreement with the experimental data.
DETERMINING THE SIGN OF Δ31 AT LONG BASELINE NEUTRINO EXPERIMENTS
Authors: NARAYAN MOHAN , SANKAR S. UMA
Published: May 2003

Recently it is advocated that high intensity and low energy (Eν~2 GeV ) neutrino beams should be built to probe the (13) mixing angle ϕ to a level of a few parts in 104. Experiments using such beams will have better signal-to-background ratio in searches for νμ→νe oscillations. We propose that such experiments can also determine the sign of Δ31 even if the beam consists of neutrinos only. By measuring the νμ→νe transitions in two different energy ranges, the effects due to propagation of neutrinos through earth's crust can be isolated and the sign of Δ31 can be determined. If the sensitivity of an experiment to ϕ is ε, then the same experiment is automatically sensitive to matter effects and the sign of Δ31 for values of ϕ≥2ε.