bluuebunny/crossref_metadata_2025 huggingface dataset:
INTEGRATING SUPER-LIOUVILLE SYSTEM WITHOUT INTEGRATION
Authors: ZHEN YI , ZHAO LIU , YANG ZHANYING
Published: May 2003

Explicit solutions of super-Liouville equation are obtained by the use of a super-extension of the so-called Drinfeld–Sokolov construction. Such solutions can be proved to be local and super-periodic using earlier results of Toppan on exchange algebras based on super-Drinfeld–Sokolov linear systems and of Babelon et al. on the proof of locality and periodicity of ordinary Toda field theories.
VIRTUAL GROMOV–WITTEN INVARIANTS AND THE QUANTUM COHOMOLOGY RINGS OF GENERAL TYPE PROJECTIVE HYPERSURFACES
Authors: JINZENJI MASAO
Published: May 2003

In this letter, we propose another characterization of the generalized mirror transformation on the quantum cohomology rings of general type projective hypersurfaces. This characteristic is useful for explicit determination of the form of the generalized mirror transformation. As an application, we rederive the generalized mirror transformation up to d=3 rational Gromov–Witten invariants obtained in our previous paper, and determine explicitly the generalized mirror transformation for the d=4,5 rational Gromov–Witten invariants in the case when the first Chern class of the hypersurface equals -H (i.e. k-N=1).
ON THE HARMONIC SUPERSPACE LANGUAGE ADAPTED TO THE GELFAND–DICKEY ALGEBRA OF DIFFERENTIAL OPERATORS
Authors: HSSAINI M. , KESSABI M. , MAROUFI B. , SEDRA M. B.
Published: May 2003

Methods developed for the analysis of nonlinear integrable models are used in the harmonic superspace (HS) framework. These methods, when applied to the HS, can lead to obtain more information about the meaning of integrability in nonlinear physical problems. Among the results obtained, we give the basic ingredients towards building in the HS language the analogue of the Gelfand–Dickey (GD) algebra of pseudo-differential operators. Some useful conventional notations and algebraic structures are also introduced to make the use of the harmonic superspace techniques more accessible.
A REAPPRAISAL OF TWO-MODE SQUEEZING AND INTERMODE COUPLING
Authors: BAGCHI B. , BHAUMIK D.
Published: May 2003

We study two-mode squeezing in the framework of generalized quantum condition and derive pedagogically the result that the two-mode squeezed state is factorizable in terms of the component single modes. We also examine the related problem of two-mode squeezing in the system of a pair of coupled oscillators and consider the effects of a sudden switching-on of the intermode coupling for these quadrature modes.
DIRAC GAMMA MATRICES AS REPRESENTATIONS OF THE ALGEBRA OF LITTLE GROUPS
Authors: BAŞKAL S.
Published: May 2003

The algebra of O (3, 3) is contracted to that of E(2)-like groups in the infinite-momentum limit. It is shown through this process that there are 18 different possibilities for the representations of E(2)-like algebra if they are to be expressed in terms of Dirac γ-matrices. It is also pointed out that the generators of this algebra are independent of the particular representation of the γ-matrices. Possible implications of this analysis is discussed.
SIMPLICIAL COMPLEXES AND THE SEMICLASSICAL LIMIT OF QUANTUM GRAVITY
Authors: DEMKIN PAUL
Published: May 2003

A model of the Euclidean quantum gravity for any dimension of the space–time is considered. The Euclidean Einstein–Regge action for the D-simplex is given in the semiclassical limit by the Gaussian integral of the corresponding 3nj-symbol. The partition function under consideration depends only on the topology of the manifold which we represent as a simplicial complex.
GROSS–NEVEU MODEL WITH OVERLAP FERMIONS
Authors: ICHINOSE IKUO , NAGAO KEIICHI
Published: May 2003

We investigate the chiral properties of overlap lattice fermion by using two-dimensional Gross–Neveu model coupled with a gauge field. Chiral properties of this model are similar to those of QCD 4, i.e. the chiral symmetry is spontaneously broken in the presence of small but finite fermion mass and also there appears the chiral anomaly because of the coupling with the gauge field. To take into consideration Lüscher's extended chiral symmetry, we insert overlap Dirac operator even in the interaction terms so that the whole action including them are invariant under the extended chiral transformation at finite lattice spacing though the interaction terms become nonlocal. We calculate mass of the quasi-Namb–Goldstone boson as a function of the bare fermion mass and two parameters in the overlap formalism and find that the quasi-Nambu–Goldstone boson has desired properties as a result of the extended chiral symmetry. Furthermore we examine the PCAC relation and find that it is satisfied at finite lattice spacing. Relationship between the anomaly term in the PCAC relation and the U(1) problem is also discussed.
ENTROPY GAP AND TIME ASYMMETRY II
Authors: AQUILANO ROBERTO , CASTAGNINO MARIO , EIROA ERNESTO
Published: May 2003

In this letter the paper [R. Aquilano and M. Castagnino, Mod. Phys. Lett.A11, 755 (1996)] is improved by considering that the main source of entropy production is the star photospheres.
A SUPERSPACE FORMULATION OF ABELIAN ANTISYMMETRIC TENSOR GAUGE THEORY
Authors: DEGUCHI SHINICHI , MANDAL BHABANI PRASAD
Published: May 2003

We apply a superspace formulation to the four-dimensional gauge theory of a massless Abelian antisymmetric tensor field of rank 2. The theory is formulated in a six-dimensional superspace using rank-2 tensor, vector and scalar superfields and their associated supersources. It is shown that BRS transformation rules of fields are realized as Euler–Lagrange equations without assuming the so-called horizontality condition in an ad hoc manner and that a generating functional [Formula: see text] constructed in the superspace reduces to that of the ordinary gauge theory of Abelian rank-2 antisymmetric tensor field. The WT identity for this theory is derived by making use of the superspace formulation and is expressed in a neat and compact form [Formula: see text].
GAMMA-RAY BURSTS AS THE BIRTH-CRIES OF BLACK HOLES
Authors: JOSHI PANKAJ S. , DADHICH NARESH K. , MAARTENS ROY
Published: May 2003

The origin of cosmic gamma-ray bursts remains one of the most intriguing puzzles in astronomy. We suggest that purely general relativistic effects in the collapse of massive stars could account for these bursts. The late formation of closed trapped surfaces can occur naturally, allowing the escape of huge energy from curvature-generated fireballs, before these are hidden within a black hole.
ULTRAVIOLET PROPERTY OF NONCOMMUTATIVE WESS–ZUMINO–WITTEN MODEL
Authors: FURUTA KO , INAMI TAKEO
Published: May 2003

We construct noncommutative extension of the Wess–Zumino–Witten (WZW) model and study its ultraviolet property at one-loop order. The β-function of the U(N) noncommutative WZW model resembles that of the ordinary WZW model at this order. The U(1) noncommutative model also has a nontrivial fixed point.
DYONS WITH AXIAL SYMMETRY
Authors: HARTMANN BETTI , KUNZ JUTTA , KLEIHAUS BURKHARD
Published: May 2003

We construct axially symmetric dyons in SU(2) Yang–Mills–Higgs theory. In the Prasad–Sommerfield limit, they are obtained via scaling relations from axially symmetric multimonopole solutions. For finite Higgs self-coupling they are constructed numerically.
DO THE PRECISE MEASUREMENTS OF THE CASIMIR FORCE AGREE WITH THE EXPECTATIONS?
Authors: SVETOVOY V. B. , LOKHANIN M. V.
Published: May 2003

An upper limit on the Casimir force is found using the dielectric functions of perfect crystalline materials which depend only on well-defined material constants. The force measured with the atomic force microscope is larger than this limit at small separations between bodies and the discrepancy is significant. The simplest modification of the experiment is proposed allowing one to make its results more reliable and answer the question if the discrepancy has any relation with the existence of a new force.
INDUCED VARIATIONAL METHOD FROM SUPERSYMMETRIC QUANTUM MECHANICS AND THE SCREENED COULOMB POTENTIAL
Authors: FILHO ELSO DRIGO , RICOTTA REGINA MARIA
Published: May 2003

The formalism of supersymmetric quantum mechanics supplies a trial wave function to be used in the variational method. The screened Coulomb potential is analyzed within this approach. Numerical and exact results for energy eigenvalues are compared.
PHENOMENOLOGICAL SCALING LAWS RELATING THE OBSERVED GALACTIC DIMENSIONS TO THE MICROSCOPIC FUNDAMENTAL SCALES
Authors: CAPOZZIELLO S. , DE MARTINO S. , DE SIENA S. , ILLUMINATI F.
Published: May 2003

It is shown that the order of magnitude of the characteristic observed radii of typical galaxies can be inferred from the microscopic fundamental scales through a phenomenological scaling law. Further scaling relations are derived, which show that such a connection can equivalently be obtained either by considering the nucleons as the elementary constituents of a galaxy, or, as more common, by considering stars as its granular components.
WEYL ANOMALY FROM WEYL GRAVITY
Authors: NOJIRI SHIN'ICHI , ODINTSOV SERGEI D.
Published: May 2003

We calculate the conformal anomaly from 5-D Weyl gravity (with broken conformal symmetry) which is conjectured to be supergravity dual to [Formula: see text] superconformal field theory via AdS/CFT correspondence. Its comparison with [Formula: see text] SCFT conformal anomaly (uv calculation) suggests that such duality may exist subject to the presence of subleading 1/N corrections to cosmological and gravitational constants.
DISCRETE WAVELET ANALYSIS FOR MULTIPARTICLE PRODUCTION EXPERIMENTS
Authors: GEORGOPOULOS G. , PETRIDIS A. , VASSILIOU M.
Published: May 2003

In high energy nucleus–nucleus collisions (SPS, RHIC, LHC) and in cosmic rays interactions, many particles are produced in the available phase space. We make an attempt to apply the wavelets technique in order to classify such events according to the event pattern and also to locate the so-called "clustering" in a distribution. After describing the method, we demonstrate its power (a) to a single event, produced by a pion condensation theoretical model, (b) to a sample of Pb–Pb simulated data at 158 GeV/c per nucleon taking into account all the experimental uncertainties.
THE PARTNERSHIP OF POTENTIALS IN QUANTUM MECHANICS AND SHAPE INVARIANCE
Authors: CARIÑENA JOSÉ F. , RAMOS ARTURO
Published: May 2003

The concept of partnership of potentials is studied in detail and in particular the non-uniqueness due to the ambiguity in the election of the factorization energy and in the choice of the solution of certain Riccati equation. We generate new factorizations from old ones using invariance under parameter transformations. The theory is illustrated with some examples.
NEW NONCLASSICAL SOLUTION ON GENERALIZED PAUL TRAP TYPE: NONCLASSICAL STUDY
Authors: RATH BISWANATH
Published: May 2003

New nonclassical solutions for the harmonic oscillator with generalized time-dependent frequency have been found. Simple expression on energy level, creation operator a†(t) and annihilation operator a(t) have been obtained. Using new solutions we want to show how to study squeezing.
CHERN–SIMONS INVARIANTS OF CLOSED HYPERBOLIC THREE-MANIFOLDS
Authors: BYTSENKO A. A. , GONÇALVES A. E. , WILLIAMS F. L.
Published: May 2003

The Chern–Simons invariants of irreducible U(n)-flat connections on compact hyperbolic three-manifolds of the form Γ\ℍ3 are derived. The explicit formula for the Chern–Simons functional is given in terms of Selberg type zeta functions related to the twisted eta invariants of Atiyah–Patodi–Singer.
THE FERMION DOUBLING PROBLEM AND NONCOMMUTATIVE GEOMETRY
Authors: BALACHANDRAN A. P. , GOVINDARAJAN T. R. , YDRI B.
Published: May 2003

We propose a resolution for the fermion doubling problem in discrete field theories based on the fuzzy sphere and its Cartesian products. Its relation to the Ginsparg–Wilson approach is also clarified.
IMPACT OF THE BOUNDS ON HIGGS MASS AND mW ON EFFECTIVE THEORIES
Authors: DIAZ-CRUZ J. L. , HERNANDEZ J. M. , TOSCANO J. J.
Published: May 2003

We study the inter-relations that exist between the present experimental bounds on the Higgs mass, as obtained from radiative corrections to mW, and the effective parameters, αi and Λ. We find that the SM bounds on mH, arising from a precise determination of the W mass, can be substantially modified by the presence of dimension-six operators which appear in the linear realization of the effective Lagrangian approach. A Higgs mass as heavy as 700 GeV can be allowed for scales of new physics of the order of 1 TeV.
GAUGING THE SHADOW SECTOR WITH SO(3)
Authors: TUPPER G. B. , LINDEBAUM R. J. , VIOLLIER R. D.
Published: May 2003

We examine the phenomenology of a low-energy extension of the Standard Model, based on the gauge group SU (3) ⊗ SU (2) ⊗ U (1)⊗ SO (3), with SO(3) operating in the shadow sector. This model offers vacuum νe → νs and νμ → ντ oscillations as the solution of the solar and atmospheric neutrino problems, and it provides a neutral heavy shadow lepton X that takes the role of a cold dark matter particle.
TORSION MODIFIED PLASMA SCREENING IN ASTROPHYSICS
Authors: SIVARAM C. , GARCIA DE ANDRADE L. C.
Published: May 2003

The torsion modified Maxwell–Proca equations when applied to describe a plasma is shown to lead to a correction to the Debye screening length. For hot new born neutron stars the torsion correction is shown to be significant. This effect may provide an indirect evidence for torsion.
CONNECTION BETWEEN Q-ALGEBRAS AND NONCANONICAL HEISENBERG ALGEBRAS
Authors: JANNUSSIS A. , BRODIMAS G.
Published: May 2003

We stress the connection between [Formula: see text]-algebras and noncanonical Heisenberg algebras. We prove that the known Heisenberg–Weyl algebras for the deformed harmonic oscillators are partial cases of the Lie-admissible [Formula: see text]-algebras. We also point out the existence of a scale factor which plays an important role for the eigenvalue spectrum and for the generalized uncertainty Heisenberg relation. This factor has the form (Δx)(Δp) ≥ ℏ′/2 with ℏ′ = ℏκ and κ > 0.
SU(d)-INVARIANT MULTIDIMENSIONAL q-OSCILLATORS WITH BOSONIC DEGENERACY
Authors: ALGIN A. , ARIK M. , ATAKISHIYEV N. M.
Published: May 2003

Multidimensional two-parameter (q1, q2)-oscillators are of two kinds: one is invariant under the (ordinary) Lie group SU (d), whereas the other is invariant under the quantum group SU q(d) where q = q1/q2. It is shown that the q1 = q2 limit of both of these two-parameter oscillators coincide and give the q-deformed Newton oscillator which can be derived from the standard quantum harmonic oscillator Newton equation. The bosonic degeneracies of the excited levels of these oscillators are different for q1 ≠ q2, but coincide in the q1 = q2 limit.
THE RAMOND–RAMOND SELF-DUAL FIVE-FORM'S PARTITION FUNCTION ON T10
Authors: DOLAN LOUISE , NAPPI CHIARA R.
Published: May 2003

In view of the recent interest in formulating a quantum theory of Ramond–Ramond p-forms, we exhibit an [Formula: see text] invariant partition function for the chiral four-form of Type IIB string theory on the ten-torus. We follow the strategy used to derive a modular invariant partition function for the chiral two-form of the M-theory five-brane. We also generalize the calculation to self-dual quantum fields in space–time dimension 2p = 2 + 4k, and display the [Formula: see text] automorphic forms for odd p > 1. We relate our explicit calculation to a computation of the B-cycle periods, which are discussed in the work of Witten.
ON TIME-DEPENDENT QUASI-EXACTLY SOLVABLE PROBLEMS
Authors: MAYER DIETER , USHVERIDZE ALEXANDER , WALCZAK ZBIGNIEW
Published: May 2003

We show that there exists a close relationship between quasi-exactly solvable quantum models and two special classes of classical dynamical systems.
BOREL–PADÉ VS BOREL–WENIGER METHOD: A QED AND A QCD EXAMPLE
Authors: CVETIČ G. , YU JI-YOUNG
Published: May 2003

Recently, Weniger (delta sequence) method has been proposed by the authors of Ref. 1 for resummation of truncated perturbation series in quantum field theories. Those authors presented numerical evidence suggesting that this method works better than Padé approximants when we resum a function with singularities in the Borel plane but not on the positive axis. We present here numerical evidence suggesting that in such cases the combined method of Borel–Padé works better than its analog Borel–Weniger, and that it may work better or comparably well in some of the cases when there are singularities on the positive axis in the Borel plane.
ON HYPER-KAHLER SINGULARITIES
Authors: BELHAJ A. , SAIDI E. H.
Published: May 2003

Using a geometric realization of the SU (2)R symmetry and a procedure of factorization of the gauge and SU (2)R charges, we study the small instanton singularities of the Higgs branch of supersymmetric U (1)r gauge theories with eight supercharges. We derive new solutions for the moduli space of vacua preserving manifestly the eight supercharges. In particular, we obtain an extension of the ordinary ADE singularities for hyper-Kahler manifolds and show that the classical moduli space of vacua is in general given by cotangent bundles of compact weighted projective spaces.
INVESTIGATION ON THE NEUTRINO INDUCED MUONS FROM ACTIVE GALACTIC NUCLEI
Authors: GUPTA NAYANTARA , BHATTACHARYYA D. P.
Published: May 2003

The fluxes of neutrino induced muons at different zenith angles have been calculated using the high energy diffused neutrino spectra emitted from blazars. We have used the standard formulation developed by Gaisser based on charge-current interactions in rock and the QED-based energy loss formulation to estimate the spectra of neutrino induced muons. The energy spectra of neutrino flux generated from blazars has been taken from the model calculations of Protheroe. The latest charge-current and total interaction cross-sections at ultrahigh energies from Kwiecinski et al. have been used to find the probability of muon generation from neutrinos and the loss of neutrinos during propagation through the Earth. We find that our derived horizontal neutrino induced muon energy spectra expected from blazar model of Protheroe is comparable with the upper limits as predicted by SOUDAN 2 experiment.
q-BOSON APPROACH TO MULTIPARTICLE CORRELATIONS
Authors: ANCHISHKIN D. V. , GAVRILIK A. M. , IORGOV N. Z.
Published: May 2003

An approach is proposed enabling one to effectively describe, for relativistic heavy-ion collisions, the observed deviation from unity of the intercept λ (measured value corresponding to zero relative momentum p of two registered identical pions or kaons) of the two-particle correlation function C(p, K). The approach uses q-deformed oscillators and the related picture of ideal gas of q-bosons. In effect, the intercept λ is connected with deformation parameter q. For a fixed value of q, the model predicts specific dependence of λ on pair mean momentum K so that, when |K|≳500–600 MeV/c for pions or when |K|≳700–800 MeV/c for kaons, the intercept λ tends to a constant which is less than unity and determined by q. If q is fixed to be the same for pions and kaons, the intercepts λπ and λK essentially differ at small mean momenta K, but tend to be equal at K large enough (|K|≳800 MeV/c), where the effect of resonance decays can be neglected. We argue that it is of basic interest to check in the experiments on heavy-ion collisions: (i) the exact shape of dependence λ=λ(K), and (ii) whether for |K|≳800 MeV/c the resulting λπ and λK indeed coincide.
ON THE SCHRÖDINGER EQUATION WITH TIME AND ITS SQUARE ROOT REPRESENTATION IN THE SUPERSYMMETRIC QUANTUM MECHANICS
Authors: TKACH V. I. , PASHNEV A. I. , ROSALES J. J.
Published: May 2003

In the present work we obtain the N=2 superconformal version of quantum mechanics with time considered as dynamical on an equal footing with other variables. The resulting supersymmetric system of constraints realizes the square root representation of the Schrödinger equation with time.
STILL FLAT AFTER ALL THESE YEARS!
Authors: PIERPAOLI ELENA , SCOTT DOUGLAS , WHITE MARTIN
Published: May 2003

The Universe could be spatially flat, positively curved or negatively curved. Each option has been popular at various times, partly affected by an understanding that models tend to evolve away from flatness. The curvature of the Universe is amenable to measurement, through tests such as the determination of the angles of sufficiently large triangles. The angle subtended by the characteristic scale on the cosmic microwave sky provides a direct test, which has now been realized through a combination of exquisite results from a number of CMB experiments.

After a long and detailed investigation, with many false clues, it now seems that the mystery of the curvature of the Universe is now solved. It is an open and shut case: the Universe is flat!
QUANTUM CREATION OF A TOPOLOGICAL BLACK HOLE
Authors: CHAO WU ZHONG
Published: May 2003

The constrained instanton method is used to study quantum creation of a vacuum or charged topological black hole. At the WKB level, the relative creation probability is the exponential of a quarter of the sum of the horizon areas associated with the seed instanton. The universe without a black hole has the highest creation probability. The difference between this creation scenario and the Hawking–Page phase transition in the anti-de Sitter background is clarified.
POSSIBILITY OF A GEOMETRIC CONSTRAINT IN THE SCHRÖDINGER QUANTUM MECHANICS
Authors: KAUSHAL R. S.
Published: May 2003

Within the framework of some straightforward mathematical terms it is argued that there exists a space-invariant in the Schrödinger quantum mechanics (SQM). As an alternative to the geometric features of localized nature dictated by the prescribed boundary conditions in a potential problem in SQM, this spatial invariant is expected to account for some global geometric features of the quantum system.
WIGGLY STRINGS IN LINEARIZED BRANS–DICKE GRAVITY
Authors: ARAZI ANDRÉS , SIMEONE CLAUDIO
Published: May 2003

The metric around a wiggly cosmic string is calculated in the linear approximation of Brans–Dicke theory of gravitation. The equations of motion for relativistic and nonrelativistic particles in this metric are obtained. Light propagation is also studied and it is shown that photon trajectories can be bounded.
A NO-CHAOS THEOREM FOR NON-MINIMALLY COUPLED SCALAR FIELD COSMOLOGY AND A NEW COSMOGENESIS SCENARIO
Authors: GUNZIG E. , BRENIG L. , FIGUEIREDO A. , FILHO T. M. ROCHA
Published: May 2003

A general dynamical system approach to classical self-consistent scalar field cosmology is presented in the framework of spatially flat FLRW space–times, for arbitrary potentials and arbitrary non-minimal coupling. We show that these universes cannot undergo chaotic behaviors, thus suggesting a possible new role of inflation in cosmology. An unexpectedly involved topology of the phase-portrait of the cosmological dynamics is exhibited: Dynamically forbidden regions, playing a crucial dynamical role, appear. A new exact critical solution, a heteroclinic orbit, connects two de Sitter inflationary regimes. We suggest a novel intriguing semiclassical cosmogenesis scenario in which the quantized scalar field could tunnel through the classically forbidden region, from the Minkowski space–time towards the nearest classically allowed solution: The critical one.
ENTROPY OF A NONSTATIC BLACK HOLE
Authors: XIANG LI , ZHENG ZHAO
Published: May 2003

We point out that the brick-wall model cannot be applied to the nonstatic black hole. In the case of a static hole, we propose a new model where the black hole entropy is attributed to the dynamical degrees of the field covering the two-dimensional membrane just outside the horizon. A cutoff different from the model of 't Hooft is necessarily introduced. It can be treated as an increase in horizon because of the space–time fluctuations. We also apply our model to the nonequilibrium and nonstatic cases, such as Schwarzschild–de Sitter and Vaidya space–times. In the nonstatic case, the entropy relies on a time-dependent cutoff.
NEUTRINO–ELECTRON PROCESSES IN A DENSE MAGNETIZED PLASMA
Authors: MIKHEEV N. V. , NARYNSKAYA E. N.
Published: May 2003

The neutrino–electron processes in a dense strongly degenerate magnetized plasma are analyzed in the framework of the Standard Model. The total probability and the mean values of the neutrino energy and momentum losses are calculated. It is shown that neutrino scattering on the excited electrons with Landau level number conservation dominates under the conditions μ2 > eB ≫ μT but does not give a contribution into the neutrino force acting on plasma along the magnetic field.
NEUTRON STARS WITH PARAMETRIZED MESON COUPLINGS
Authors: TAURINES A. R. , VASCONCELLOS C. A. Z. , MALHEIRO M. , CHIAPPARINI M.
Published: May 2003

We investigate static properties of nuclear and neutron star matter by using a relativistic mean field theory with parametrized couplings. With a suitable choice of mathematical parameters, the couplings allow one to reproduce results of current quantum hadrodynamics models. For other parametrizations, a better description of bulk properties of nuclear matter is obtained. The formalism is extended to include hyperon and lepton degrees of freedom, and an analysis on the effects of the phenomenological couplings in the fermion populations and mass of neutron stars is performed. The results show a strong similarity between the predictions of ZM-like models and those with exponential couplings. We have observed in particular an extreme sensibility of the predictions of these theories on the specific choice of the values of the binding energy of nuclear matter and saturation density. Additionally, the role of the very intense scalar meson mean field found in the interior of neutron stars in the screening of the nucleon mass is discussed.
SOME DYNAMICAL EFFECTS OF THE COSMOLOGICAL CONSTANT
Authors: AXENIDES M. , FLORATOS E. G. , PERIVOLAROPOULOS L.
Published: May 2003

Newton's law gets modified in the presence of a cosmological constant by a small repulsive term (antigravity) that is proportional to the distance. Assuming a value of the cosmological constant consistent with the recent SnIa data (Λ≃10-52 m-2), we investigate the significance of this term on various astrophysical scales. We find that on galactic scales or smaller (less than a few tens of kpc), the dynamical effects of the vacuum energy are negligible by several orders of magnitude. On scales of 1 Mpc or larger however we find that the vacuum energy can significantly affect the dynamics. For example we show that the velocity data in the local group of galaxies correspond to galactic masses increased by 35% in the presence of vacuum energy. The effect is even more important on larger low density systems like clusters of galaxies or superclusters.
A PRIORI MIXING OF MESONS AND THE |ΔI|=1/2 RULE IN K→ππ
Authors: GARCÍA A. , HUERTA R. , SÁNCHEZ-COLÓN G.
Published: May 2003

We consider the hypothesis of a priori mixings in the mass eigenstates of mesons to obtain the |ΔI|=1/2 rule in K→ππ. The Hamiltonian responsible for the transition is the strong interacting one. The experimental data are described using the isospin symmetry relations between the strong coupling constants.
p-BRANE ACTION FROM GRAVI-DILATON EFFECTIVE ACTION
Authors: NIETO J. A. , YEE C. M.
Published: May 2003

Using a special ansatz for the metric, by straightforward computation we prove that gravi-dilaton effective action in higher dimensions is reduced to the p-brane action. The dual symmetry of the generic type a↔1/a is an important symmetry of the reduced action.
QUASI-EXACTLY SOLVABLE MATRIX SCHRÖDINGER OPERATORS
Authors: BRIHAYE YVES
Published: May 2003

Two families of quasi-exactly solvable 2×2 matrix Schrödinger operators are constructed. The first one is based on a polynomial matrix potential and depends on three parameters. The second is a one-parameter generalization of the scalar Lamé equation. The relationship between these operators and QES Hamiltonians already considered in the literature is pointed out.
STATIC AND NONSTATIC QUANTUM EFFECTS IN TWO-DIMENSIONAL DILATON GRAVITY
Authors: CHIOU-LAHANAS C. , DIAMANDIS G. A. , GEORGALAS B. C. , KAPELLA-EKONOMOU A. , MAINTAS X. N.
Published: May 2003

We study back-reaction effects in two-dimensional dilaton gravity. The back-reaction comes from an R2 term which is a part of the one-loop effective action arising from massive scalar field quantization in a certain approximation. The peculiarity of this term is that it does not contribute to the Hawking radiation of the classical black hole solution of the field equations. In the static case we examine the horizon and the physical singularity of the new black hole solutions. Studying the possibility of time dependence we see the generation of a new singularity. The particular solution found still has the structure of a black hole, indicating that nonthermal effects cannot lead, at least in this approximation, to black hole evaporation.
NON-ABELIAN FRACTIONAL SUPERSYMMETRY IN TWO DIMENSIONS
Authors: AHMEDOV HAJI , DAYI ÖMER F.
Published: May 2003

Non-Abelian fractional supersymmetry algebra in two dimensions is introduced utilizing Uq(sl(2,ℝ)) at roots of unity. Its representations and the matrix elements are obtained. The dual of it is constructed and the corepresentations are studied. Moreover, a differential realization of the non-Abelian fractional supersymmetry generators is given in the generalized superspace defined by two commuting and two generalized Grassmann variables. An invariant action under the fractional supersymmetry transformations is given.
AN ANALYTIC SOLUTION OF HYDRODYNAMIC EQUATIONS WITH SOURCE TERMS IN HEAVY-ION COLLISIONS
Authors: ZHUANG PENGFEI , YANG ZHENWEI , HUANG MEI , ZHAO WEIQIN
Published: May 2003

The energy and baryon densities in heavy-ion collisions are estimated by analytically solving a (1+1)-dimensional hydrodynamical model with source terms. In particular, a competition between the energy and baryon sources and the expansion of the system is discussed in detail.
A CALCULATION OF HIGGS MASS IN THE STANDARD MODEL
Authors: PASUPATHY J.
Published: May 2003

The assumption that the ratio of the Higgs self-coupling to the square of its Yukawa coupling to the top is (almost) independent of the renormalization scale fixes the Higgs mass within narrow limits at m H =160 GeV using only the values of gauge couplings and top mass.
SELF-FORCE ON TIME-DEPENDENT POINTLIKE SOURCE IN THE SPACE OF A DISCLINATION
Authors: AZEVEDO SÉRGIO
Published: May 2003

In this paper we obtain the solution of the Helmholtz equation, using Linet's approach to the space of a disclination. We also calculate the time-dependent electric self-forces on a pointlike charge.
COMMENT ON AMBIGUITIES IN THE HOLOGRAPHIC WEYL ANOMALY
Authors: FUKUMA MASAFUMI , SAKAI TADAKATSU
Published: May 2003

We consider possible ambiguities in the holographic Weyl anomaly that may arise from local terms in the flow equation. We point out that such ambiguities actually do not give physically meaningful contributions to the Weyl anomaly.
HOLOMORPHIC EFFECTIVE ACTION OF N=2 SYM THEORY FROM HARMONIC SUPERSPACE WITH CENTRAL CHARGES
Authors: EREMIN S. , IVANOV E.
Published: May 2003

We compute the one-loop holomorphic effective action of the massless Cartan sector of N=2 SYM theory in the Coulomb branch, taking into account the contributions both from the charged hypermultiplets and off-diagonal components of the gauge superfield. We use the manifestly supersymmetric harmonic superfields diagram techniques adapted to N=2 supersymmetry with the central charges induced by Cartan generators. The (anti)holomorphic part proves to be proportional to the central charges and it has the generic form of Seiberg's action obtained by integrating U (1)R anomaly. It vanishes for N=4 SYM theory, i.e. the coupled system of N=2 gauge superfield and hypermultiplet in the adjoint representation.
ON THE QUANTUM BRST STRUCTURE OF CLASSICAL MECHANICS
Authors: MARNELIUS ROBERT
Published: May 2003

The BRST–antiBRST invariant path integral formulation of classical mechanics of Gozzi et al. is generalized to pseudomechanics. Projections to physical propagators by BRST–antiBRST invariant boundary conditions are considered. The formulation is also viewed from recent group theoretical results within BRST–antiBRST invariant theories. A natural bracket expressed in terms of BRST and antiBRST charges in the extended formulation is shown to be equal to the Poisson bracket. Several remarks on the operator formulation are made.
A CONFORMAL FIELD THEORY DESCRIPTION OF THE PAIRED AND PARAFERMIONIC STATES IN THE QUANTUM HALL EFFECT
Authors: CRISTOFANO GERARDO , MAIELLA GIUSEPPE , MAROTTA VINCENZO
Published: May 2003

We extend the construction of the effective conformal field theory for the Jain hierarchical fillings proposed in Ref. 1 to the description of a quantum Hall fluid at nonstandard fillings [Formula: see text]. The chiral primary fields are found by using a procedure which induces twisted boundary conditions on the m scalar fields; they appear as composite operators of a charged and neutral component. The neutral modes describe parafermions and contribute to the ground state wave function with a generalized Pfaffian term. Correlators of Ne electrons in the presence of quasi-hole excitations are explicitly given for m=2.
QUANTUM GROUPS AND FIELD THEORY
Authors: FINKELSTEIN R. J.
Published: May 2003

When the symmetry of a physical theory describing a finite system is deformed by replacing its Lie group by the corresponding quantum group, the operators and state function will lie in a new algebra describing new degrees of freedom. If the symmetry of a field theory is deformed in this way, the enlarged state space will again describe additional degrees of freedom, and the energy levels will acquire fine structure. The massive particles will have a stringlike spectrum lifting the degeneracy of the point-particle theory, and the resulting theory will have a nonlocal description. Theories of this kind naturally contain two sectors with one sector lying close to the standard theory while the second sector describes particles that should be more difficult to observe.
THE WEYL GAUGE THEORY AND ABSOLUTE PARALLELISM
Authors: PESTOV A. B.
Published: May 2003

The Weyl spinor field is a spinor representation of the Weyl non-Abelian gauge group and a source of the Weyl non-Abelian gauge field first originated in 1921. The equation is derived for the Weyl spinor field on the Weitzenböck space–time that has a quadruplet of parallel vector fields as the fundamental structure. The connection between the Weyl non-Abelian gauge theory and the Weitzenböck space–time is established in the form of a consistent system of equations for the Weyl spinor field and the quadruplet of parallel vector fields.
INFLUENCE OF THE MAGNETIC FIELD ON THE FERMION SCATTERING OFF BUBBLE AND KINK WALLS
Authors: CEA P. , FOGLI G. L. , TEDESCO L.
Published: May 2003

We investigate the scattering of fermions off domain walls at the electroweak phase transition in the presence of a magnetic field. We consider both the bubble wall and the kink domain wall. We derive and solve the Dirac equation for fermions with momentum perpendicular to the walls, and compute the transmission and reflection coefficients. In the case of kink domain wall, we briefly discuss the zero mode solutions localized on the wall. The possible role of the magnetic field for the electroweak baryogenesis is also discussed.
QUANTUM EQUIVALENT OF THE BERTRAND'S THEOREM
Authors: GURAPPA N. , PANIGRAHI PRASANTA K. , RAJU T. SOLOMAN , SRINIVASAN V.
Published: May 2003

A procedure for constructing general bound state potentials is given. Analogous to the Bertrand's theorem in classical mechanics, we then identify radial eigenvalue problems possessing exact solvability and infinite number of eigenstates. Akin to the classical result, the only special cases of the general central potential, satisfying the above two conditions, are the Coulomb and harmonic oscillator potentials.
ON SUB-MILLIMETER FORCES FROM EXTRA DIMENSIONS
Authors: DVALI GIA , GABADADZE GREGORY , PORRATI MASSIMO
Published: May 2003

We show that in theories with large extra dimensions forces mediated by a bulk dilaton and bulk gauge fields may be parametrically (exponentially) weaker than gravity due to the suppression of their wave functions on a brane. This is the case when dilaton gets stabilized by certain strongly coupled dynamics on the brane, or the bulk gauge symmetries are spontaneously broken by the Higgs mechanism on the worldvolume. At distances smaller than the size of a largest extra dimension these particles produce the force-law which decreases with distance faster than high-dimensional gravity. For a millimeter size extra dimensions predicted deviations are in the range which may be detected in sub-millimeter gravity measurements.
HEAVY QUARK PHOTOPRODUCTION IN THE SEMIHARD QCD APPROACH AND THE UNINTEGRATED GLUON DISTRIBUTION
Authors: LIPATOV A. V. , SALEEV V. A. , ZOTOV N. P.
Published: May 2003

Processes of heavy quark photoproduction at HERA energies are considered using the semihard (k⊥ factorization) QCD approach with emphasis of the BFKL dynamics of gluon distributions. We investigate the dependences of the total cross-section of heavy quark photoproduction and also the pT distribution on different forms of the unintegrated gluon distribution. We present a comparison of the theoretical results with available H1 and ZEUS experimental data for charm and beauty photoproductions.
ON THE MIXING OF THE SCALAR MESONS f0(1370), f0(1500) AND f0(1710)
Authors: LI DE-MIN , YU HONG , SHEN QI-XING
Published: May 2003

Based on a 3×3 mass matrix describing the mixing of the scalar states f0(1370), f0(1500) and f0(1710), the hadronic decays of the three states into two pseudoscalar mesons are investigated. Under the possible assumption concerning the mass level order of the bare states [Formula: see text] and |G>=|gg> in the scalar sector, MG > MN > MS, the implications of some of the observed branching ratios for the glueball–quarkonia content of the three states are studied. Some predictions about the decays of the three states are presented, which can provide stringent consistency checks for our assumption.
"SELF-TUNING" AND CONFORMALITY
Authors: KAKUSHADZE ZURAB
Published: May 2003

We consider an infinite-volume brane world setup where a codimension one-brane is coupled to bulk gravity plus a scalar field with vanishing potential. The latter is protected by bulk supersymmetry, which is intact even if brane supersymmetry is completely broken as the volume of the extra dimension is infinite. Within this setup we discuss a flat solution with a "self-tuning" property, i.e. such a solution exists for a continuous range of values for the brane tension. This infinite-volume solution is free of any singularities, and has the property that the brane cosmological constant is protected by bulk supersymmetry. We, however, also point out that consistency of the coupling between bulk gravity and brane matter generically appears to require that the brane world-volume theory be conformal.
ASSOCIATED LAMÉ EQUATION, PERIODIC POTENTIALS AND sl(2, ℝ)
Authors: GANGULY ASISH
Published: May 2003

We propose a new approach based on the algebraization of the associated Lamé equation [Formula: see text] within sl(2, ℝ) to derive the corresponding periodic potentials. The band edge eigenfunctions and energy spectra are explicitly obtained for integers m, l. We also obtain the explicit expressions of the solutions for half-integer m and integer or half-integer l.
PHOTONS AND STATIC GRAVITY
Authors: OKUN L. B.
Published: May 2003

The influence of static gravitational field on frequency, wavelength and velocity of photons and on the energy levels of atoms and nuclei is considered in the most elementary way. The interconnection between these phenomena is stressed.
THE ISSUE OF CHOOSING NOTHING: WHAT DETERMINES THE LOW ENERGY VACUUM STATE OF NATURE?
Authors: PADMANABHAN T. , CHOUDHURY T. ROY
Published: May 2003

Starting from an (unknown) quantum gravitational model, one can invoke a sequence of approximations to progressively arrive at quantum field theory (QFT) in curved space–time, QFT in flat space–time, nonrelativistic quantum mechanics and Newtonian mechanics. The more exact theory can put restrictions on the range of possibilities allowed for the approximate theory which are not derivable from the latter — an example being the symmetry restrictions on the wave function for a pair of electrons. We argue that the choice of vacuum state at low energies could be such a "relic" arising from combining the principles of quantum theory and general relativity, and demonstrate this result in a simple toy model. Our analysis suggests that the wave function of the universe, when describing the large volume limit of the universe, dynamically selects a vacuum state for matter fields — which in turn defines the concept of particle in the low energy limit. The result also has the potential for providing a concrete quantum mechanical version of Mach's principle.
ELECTROSTATIC IN REISSNER–NORDSTRÖM SPACE–TIME WITH A CONICAL DEFECT
Authors: SPINELLY J. , BEZERRA V. B.
Published: May 2003

We calculate the electrostatic potential generated by a point charge at rest in Reissner–Nordström space–time with a conical defect. An expression for the self-energy is also presented.
REMARKS UPON THE MASS OSCILLATION FORMULAS
Authors: DE LEO STEFANO , DUCAT GISELE , ROTELLI PIETRO
Published: May 2003

The standard formula for mass oscillations is often based upon the approximation t≈L and the hypotheses that neutrinos have been produced with a definite momentum p or, alternatively, with definite energy E. This represents an inconsistent scenario and gives an unjustified reduction by a factor of two in the mass oscillation formulas. Such an ambiguity has been a matter of speculations and mistakes in discussing flavor oscillations. We present a series of results and show how the problem of the factor two in the oscillation length is not a consequence of Gedanken experiments, i.e. oscillations in time. The common velocity scenario yields the maximum simplicity.
THE FERMIONIC ENTROPY OF SPHERICALLY SYMMETRIC BLACK HOLES
Authors: SHEN YOU-GEN
Published: May 2003

The free energy and entropy for Dirac field is derived in the general spherically symmetric black hole background, by using 't Hooft's brick wall model. It is found that, in such a black hole background, fermionic entropy is 7/2 times the value of bosonic entropy.
FORCE IN KAPPA-DEFORMED RELATIVISTIC DYNAMICS
Authors: CZERHONIAK PIOTR
Published: May 2003

We consider the physical implications of various choices of the three-momentum basis in the κ-deformed Poincaré algebra. In particular, we find that the energy dependence of the velocity of a κ-particle leads to unexpected features in κ-deformed kinematics. We also discuss the notion of force in κ-deformed dynamics, and as a tool example we investigate the motion of a κ-deformed particle under the action of a constant force.
HARD JET PROBES IN TERMS OF COLORLESS QCD DIPOLES
Authors: PESCHANSKI R.
Published: May 2003

The forward jet playing the role of a hard probe in high energy QCD scattering is analyzed in terms of QCD dipole (color-singlet [Formula: see text]) configurations in the transverse position space. There are sizable differences with the analogous [Formula: see text] configurations of a hard photon probe which may lead to significant phenomenological consequences on the analysis of hard processes using a forward jet probe, e.g. at the Tevatron. A geometrical interpretation of the resulting distribution in terms of black disk diffraction is proposed.
A NOTE ON WEYL TRANSFORMATIONS IN TWO-DIMENSIONAL DILATON GRAVITY
Authors: CAVAGLIÀ MARCO
Published: May 2003

We discuss Weyl (conformal) transformations in two-dimensional matterless dilaton gravity. We argue that both classical and quantum dilaton gravity theories are invariant under Weyl transformations.
TRACE ANOMALY AND CASIMIR EFFECT
Authors: SETARE M. R. , REZAEIAN A. H.
Published: May 2003

The Casimir energy for scalar field of two parallel conductors in two-dimensional domain wall background, with Dirichlet boundary conditions, is calculated by making use of general properties of renormalized stress–tensor. We show that vacuum expectation values of stress–tensor contain two terms which come from the boundary conditions and the gravitational background. In two dimensions the minimal coupling reduces to the conformal coupling and stress–tensor can be obtained by the local and nonlocal contributions of the anomalous trace. This work shows that there exists a subtle and deep connection between Casimir effect and trace anomaly in curved space–time.
IMPROVED DIRAC QUANTIZATION OF A FREE PARTICLE
Authors: HONG SOON-TAE , TAE KIM WON , PARK YOUNG-JAI
Published: May 2003

In the framework of Dirac quantization with second-class constraints, a free particle moving on the surface of a (d-1)-dimensional sphere has an ambiguity in the energy spectrum due to the arbitrary shift of canonical momenta. We explicitly show that this spectrum obtained by the Dirac method is consistent with the result of the Batalin–Fradkin–Tyutin formalism, which is an improved Dirac method, at the level of the first-class constraint by fixing the ambiguity, and discuss its physical consequences.
IMPLICATIONS OF THE UNITARITY TRIANGLE "uc" FOR J, δ AND |VCKM| ELEMENTS
Authors: RANDHAWA MONIKA , BHATNAGAR V. , GILL P. S. , GUPTA M.
Published: May 2003

The Jarlskog rephasing invariant parameter |J| is evaluated using one of the six unitarity triangles involving well-known CKM matrix elements |Vud|, |Vus|, |Vub/Vcb|, |Vcd|, |Vcs|, and |Vcb|. With PDG2000 values of |Vud| etc. as input, we obtain |J|= (2.71±1.12)×10-5, which in the PDG representation of CKM matrix leads to the range 21° to 159° for the CP violating phase δ.

The CKM matrix elements evaluated using this range of δ are in agreement with the PDG CKM matrix. The implications of refinements in the input on |J|, δ and CKM matrix elements have also been studied.
TESTING κ-POINCARÉ WITH NEUTRAL KAONS
Authors: AMELINO-CAMELIA GIOVANNI , BUCCELLA FRANCO
Published: May 2003

In recent work on experimental tests of quantum-gravity-motivated phenomenological models, a significant role has been played by the so-called "κ" deformations of Poincaré symmetries. Sensitivity to values of the relevant deformation length λ as small as 5×10-33 m has been achieved in recent analyses comparing the structure of κ-Poincaré symmetries with data on the gamma rays we detect from distant astrophysical sources. We investigate violations of CPT symmetry which may be associated with κ-Poincaré in the physics of the neutral-kaon system. A simple estimate indicates that experiments on the neutral kaons may actually be more λ-sensitive than the corresponding astrophysical experiments, and may already allow to probe values of λ of order the Planck length.
ENERGY OF A CONFORMAL SCALAR DYON BLACK HOLE
Authors: RADINSCHI I.
Published: May 2003

We obtain the energy of a conformal scalar dyon black hole (CSD) by using the energy–momentum complexes of Tolman and Möller. The total gravitational energy is given by the CSD charge in both prescriptions.
ON THE NATURAL GAUGE FIELDS OF MANIFOLDS
Authors: PESTOV A. B. , SAHA BIJAN
Published: May 2003

The gauge symmetry inherent in the concept of manifold has been discussed. Within the scope of this symmetry the linear connection or displacement field can be considered as a natural gauge field on the manifold. The gauge-invariant equations for the displacement field have been derived. It has been shown that the energy–momentum tensor of this field conserves and hence the displacement field can be treated as one that transports energy and gravitates. To show the existence of the solutions of the field equations, we have derived the general form of the displacement field in Minkowski space–time which is invariant under rotation and space and time inversion. With this ansatz we found spherically-symmetric solutions of the equations in question.