bluuebunny/crossref_metadata_2025 huggingface dataset:
A CLOSED EXPRESSION FOR THE UNIVERSAL ℛ-MATRIX IN A NON-STANDARD QUANTUM DOUBLE
Authors: VLADIMIROV A.A.
Published: November 2004

In recent papers by the author, a method was developed for constructing quasitriangular Hopf algebras (quantum groups) of the quantum-double type. As a by-product, a novel non-standard example of the quantum double has been found. In this letter, a closed expression (in terms of elementary functions) for the corresponding universal ℛ-matrix is obtained. In reduced form, when the number of generators becomes two instead of four, this quantum group can be interpreted as a deformation of the Lie algebra [x, h]=2h in the context of Drinfeld’s quantization program.
RIGID QED AND NONLINEAR SIGMA MODELS
Authors: AWADA M. , MA M. , ZOLLER DAVID
Published: November 2004

We show that in the absence of Coulomb interactions the kinetic theory of a recently proposed new model of strongly coupled QED behaves like an enhanced two-dimensional nonlinear sigma model with O(D+1) symmetry in Euclidean signature (which becomes an on-compact O(D, 1) symmetry in Minkowski signature). The beta-function is nontrivial in the absence of virtual fermions due to the non-perturbative vacuum fluctuation of the gauge field. In the presence of Coulomb the running coupling approaches an uv stable fixed point αc of order one. In the weak phase the curvature coupling increases at short distances and decreases at large distances.
A CONFORMAL AFFINE TODA MODEL OF 2D BLACK HOLES: A QUANTUM STUDY OF THE EVAPORATION END POINT
Authors: BELGIORNO F. , CATTANEO A.S. , FUCITO F. , MARTELLINI M.
Published: November 2004

In this paper we reformulate the dilaton-gravity theory of Callan et al. as a new effective conformal field theory which turns out to be a generalization of the so-called SL 2-conformal affine Toda (CAT) theory studied some time ago by Babelon and Bonora. We quantize this model, thus keeping in account the dilaton-gravity quantum effects. We then implement a Renormalization Group analysis to study the black hole thermodynamics and the final state of the Hawking evaporation.
THE TWO-PARAMETRIC EXTENSION OF h DEFORMATION OF GL(2), AND THE DIFFERENTIAL CALCULUS ON ITS QUANTUM PLANE
Authors: AGHAMOHAMMADI AMIR
Published: November 2004

We present an alternative two-parametric deformation GL (2)h,h′, and construct differential calculus on the quantum plane on which this quantum group acts. We also give a new deformation of the two-dimensional Heisenberg algebra.
SIZE OF MULTIPLY-CONNECTED UNIVERSE AND COSMIC BACKGROUND RADIATION
Authors: FANG LI-ZHI
Published: November 2004

A few years ago, we proposed that the spatial topology of the universe can be detected by cosmic background radiation (CBR), because the amplitudes of the spherical harmonic expansion of CBR anisotropy are sensitively dependent on the size of the universe. Recently, this method has been applied to study the size of a T3 universe by using the COBE-DMR data of CBR temperature fluctuation. The new result of the lower limit to the cosmologically spatial size is found to be larger than the old values by a factor of about 5. Therefore, the model of cubic T3 small universe can be ruled out. This paper is a summary of this progress. The significance and remained problems of the spatial topology of the universe have also been discussed.
LIE-GROUP TREATMENT FOR TWO- AND THREE-NEUTRINO OSCILLATIONS IN MATTER WITH ARBITRARY DENSITY VARIATIONS
Authors: PRANTS S. V.
Published: November 2004

We develop a novel approach for treating in a unified manner the problem of N-neutrino oscillations in matter with density that varies in an arbitrary way along a neutrino's path. It is shown that the class of density functions, permitting exact analytic solutions for the two-flavor survival probability, can be considerably enlarged. For three flavors, we propose a general analytic scheme for calculating the non-adiabatic evolution of a neutrino state near the resonances.
CRITICAL BEHAVIOR OF TARGET SPACE MEAN FIELD THEORY
Authors: WEXLER MARK
Published: November 2004

Recently, the free energy of the target space mean field (TSMF) matrix model has been calculated in the low temperature phase, order-by-order in a low temperature expansion. The TSMF model is a matrix model whose discrete target space has an infinite coordination number, and whose free energy assumes a universal form, corresponding to baby universes joined into a tree. Here the free energy is summed to all orders, and expressed through a transcendental algebraic equation, using which we analyze the critical phenomena that occur in the TSMF model. There are two critical curves, at which the matter and the geometry become critical, and for which the critical exponents are [Formula: see text] and [Formula: see text], respectively. There is a bi-critical point where the curves meet, at which [Formula: see text].
EXACT SUPERSYMMETRIC AMPLITUDE FOR $K^0 \hbox{-}\bar K^0$ AND $B^0 \hbox{-}\bar B^0$ MIXING
Authors: HAGELIN JOHN S. , KELLEY S. , TANAKA TOSHIAKI
Published: November 2004

We present the most general supersymmetric amplitude for [Formula: see text] and [Formula: see text] mixing resulting from gluino box diagrams. We use this amplitude to place general constraints on the magnitude of flavor-changing squark mass mixings, and compare these constraints with theoretical predictions both in and beyond the Minimal Supersymmetric Standard Model.
A NOTE ON EFFECTIVE STRING THEORY
Authors: CHAUDHURI SHYAMOLI , MINIC DJORDJE
Published: November 2004

Motivated by the possibility of an effective string description for the ir limit of pure Yang-Mills theory, we present a toy model for an effective theory of random surfaces propagating in a target space of D > 2. We show that the scaling exponents for the fixed area partition function of the theory are apparently well behaved. We make some observations regarding the usefulness of this toy model.
WEAK LEPTONIC DECAY OF LIGHT AND HEAVY PSEUDOSCALAR MESONS IN A FIELD-THEORETIC QUARK MODEL
Authors: MAHARANA L. , NATH A. , PANDA A. R.
Published: November 2004

Weak leptonic decays of light and heavy pseudoscalar mesons are studied in a field-theoretic quark model where the mesons are described by constituent quarks and antiquarks with a particular ansatz and a Harmonic oscillator wave function. With constituent quark masses and Harmonic oscillator radii for mesons as parameters of the model, decay constants are calculated and found as (fπ, fk, fD, fB) = (132 MeV , 161 MeV , 160 MeV , 115 MeV ) indicating a reasonable agreement with the experimental data wherever available. Partial decay widths and branching ratios for kinematically allowed leptonic decay processes are also estimated and compared with the experiments wherever available.
VECTOR INDUCED LATTICE GAUGE THEORIES
Authors: PESANDO IGOR
Published: November 2004

We consider vector induced lattice gauge theories, in particular we consider the QED induced and we show that at negative temperature corresponds to the dimer problem while at positive temperature it describes a gas of branched polymers with loops. We show that the fermionic models have D c = 6 as upper critical dimension for N ≠ ∞ while the N = ∞ model has no upper critical dimension. We also show that the bosonic models without potential are not critical in the range of stability of the integral definition of the partition function but they behave as the fermionic models when we analytically continue the free energy.
QUANTUM FLUCTUATIONS WITH STRONG CURVATURE COUPLING
Authors: FAKIR REDOUANE , HABIB SALMAN
Published: November 2004

We compute the quantum fluctuations of a non-minimally coupled self-interacting scalar field around a classical self-consistent inflationary solution; this system is free of the instability usually associated with negative curvature couplings. By conformally transforming the original system it is possible to eliminate the direct coupling of the field to the curvature. Investigating the quantum fluctuations in this "conformal frame," where it is possible to do a more complete calculation, and using the same criteria for selecting the quantum state in both frames, we find the results in the two frames to be incompatible with each other. This illustrates, in a specific example, the inherent ambiguity in relating the quantum behavior of two systems that are connected by a field-dependent conformal transformation at the classical level if one follows the usual naive approach. for estimating density perturbations in inflation. Possible ways to get around this problem are discussed.
QUANTUM CORRECTIONS TO THE ELECTROWEAK SPHALERON TRANSITION
Authors: BAACKE J. , JUNKER S.
Published: November 2004

We have performed a new exact evaluation of the fluctuation determinant κ of the electroweak sphaleron with ΘW = 0. The results differ significantly from a previous calculation of this quantity by Carson et al. We find that κ is of order 1 in units (gυ)6 while the previous results indicated a strong suppression of the sphaleron transition by this factor.
QUANTUM HOLONOMY ON A LATTICE
Authors: CHIU T. W. , LEE H. C.
Published: November 2004

The quantum holonomy associated with a set of contours on a lattice is shown to be a Casimir operator of the gauge group. Its value in an irreducible representation of the group is the unit matrix times a c-number. This assertion is verified numerically on a 4D lattice for the SU(3) pure gauge theory for cases of the set containing one and two contours. The group-valued quantum holonomy contains more useful information than the character-valued Wilson loop in aspects that could be crucial. The quantum holonomy of a set of loops could serve as an observable for measuring the correlations between the gauge loops.
FUSION RULES, TOPOLOGICAL QUANTUM MECHANICS AND THREE-MANIFOLDS
Authors: GUILARTE JUAN MATEOS
Published: November 2004

Path-integral quantization of Chern-Simons field theory in the Hamiltonian formalism is developed. A derivation of Verlinde algebra in topological quantum mechanics arises and three-manifold invariants are recovered.
INFLATION, DEFLATION, AND FRAME-INDEPENDENCE IN STRING COSMOLOGY
Authors: GASPERINI M. , VENEZIANO G.
Published: November 2004

The inflationary scenarios suggested by the duality properties of string cosmology in the Brans-Dicke (or string) frame are shown to correspond to accelerated contraction (deflation) when Weyl transformed to the Einstein frame. We point out that the basic virtues of inflation (solving the flatness and horizon problems, amplifying vacuum fluctuations, etc.) have physically equivalent counterparts in the deflationary (Einstein-frame) picture. This could be the answer to some objections recently raised to superstring cosmology.
TAMM-DANCOFF DEFORMATION OF BOSONIC OSCILLATOR ALGEBRAS
Authors: CHATURVEDI S. , SRINIVASAN V. , JAGANNATHAN R.
Published: November 2004

The Tamm-Dancoff (TD) deformation of the boson oscillator incorporates a high energy cutoff in its spectrum. It is found that one can obtain a similar deformation of any generalized bosonic oscillator algebra. The Hopf (or ‘quantum’) algebraic aspects of the TD-deformation are discussed. Examples are given.
GENERALIZED YANG-BAXTER EQUATION
Authors: KASHAEV R. M. , STROGANOV YU. G.
Published: November 2004

A generalization of the Yang-Baxter equation is proposed. It enables us to construct integrable two-dimensional lattice models with commuting two-layer transfer matrices, while single-layer ones are not necessarily commutative. Explicit solutions to the generalized equations are found. They are related with Boltzmann weights of the sl (3) chiral Potts models.
THE LAMB SHIFT IN THE CHARGE-MAGNETIC MONOPOLE SYSTEM
Authors: BARUT A. O. , SHNIR YA. M. , TOLKACHEV E. A.
Published: November 2004

The radiative corrections to the spectrum of the bound charge-dyon system are considered in the framework of the self-field QED as well as in the Pauli approximation.
ANOMALOUS DIMENSIONS OF SOFT OPERATORS IN SUPERSYMMETRIC NONLINEAR SIGMA-MODELS
Authors: WIESE KAY JÖRG
Published: November 2004

The renormalization ζ-function for supersymmetric nonlinear sigma-models is calculated up to three-loop order. For a wide class of models, which includes the N-vector model and matrix models, the result can be summarized as follows: If the ζ-function for the bosonic model is [Formula: see text], then the ζ-function for the supersymmetric model takes the form [Formula: see text]. This is the case for arbitrary harmonic polynomials of the field variables (so called "soft operators").
SUPERCONDUCTIVITY: GAUGE FIELD THEORY FORMULATION
Authors: ACHARYA R. , SWAMY P. NARAYANA
Published: November 2004

The nonrelativistic BCS theory of superconductivity is studied in the framework which allows an application of field-theoretic methods. The gauge technique of relativistic quantum electrodynamics is shown to be a suitable basis which makes it feasible to extend BCS theory beyond the original weak coupling approximation. We derive a relation between the superconducting transition temperature, the Debye temperature, the effective coupling constant and the effective electron mass. In addition to the BCS type solution, we establish an interesting new solution which corresponds to a high transition temperature.
PICARD-FUCHS EQUATIONS AND SPECIAL GEOMETRY
Authors: CERESOLE A. , D’AURIA R. , FERRARA S. , LERCHE W. , LOUIS J.
Published: November 2004

We investigate the system of holomorphic differential identities implied by special Kählerian geometry of four-dimensional N=2 supergravity. For superstring compactifications on Calabi-Yau threefolds these identities are equivalent to the Picard-Fuchs equations of algebraic geometry that are obeyed by the periods of the holomorphic three-form. For one variable they reduce to linear fourth-order equations which are characterized by classical W generators; we find that the instanton corrections to the Yukawa couplings are directly related to the nonvanishing of w4. We also show that the symplectic structure of special geometry can be related to the fact that the Yukawa couplings can be written as triple derivatives of some holomorphic function F. Moreover, we give the precise relationship of the Yukawa couplings of special geometry with three-point functions in topological field theory.
SELF-INDUCED ANOMALOUS SCALING OF A 2D FERMION ON A TORUS
Authors: BERGER THILO
Published: November 2004

Self-induced anomalous scaling of a 2D fermion on a torus is studied in the conformal gauge. The fermion propagator is calculated by using a perturbation theoretic approach. The result for the scaling dimension coincides with the one which follows from the procedure developed by David7 and Distler and Kawai.8
ON THE BOUSSINESQ HIERARCHY AND REALIZATION OF W3-SYMMETRY
Authors: GHOSH S. , ROY S.
Published: November 2004

The Boussinesq hierarchy equation can be regarded as W3-gravity Ward identity from Polyakov-type gauge fixing on SL (3, R) Lie algebra valued gauge fields through proper identification of the fields. We clarify its relation with the W3-gravity obtained by Hull through gauging the chiral W3-symmetry of a free scalar field theory.
LIOUVILLE GRAVITY ON BORDERED SURFACES
Authors: JASKÓLSKI ZBIGNIEW
Published: November 2004

The functional quantization of the Liouville gravity on bordered surfaces in the conformal gauge is developed. It was shown that the geometrical interpretation of the Polyakov path integral as a sum over bordered surfaces uniquely determines the boundary conditions for the fields involved. The gravitational scaling dimensions of boundary and bulk operators and the critical exponents are derived. In particular the boundary Hausdorff dimension is calculated.
CHIRAL SUPERPARTICLE AND THE FULL SET OF (1,0) SUPERGRAVITY CONSTRAINTS
Authors: DERIGLAZOV A.A.
Published: November 2004

We present BFV quantization of manifestly Lorentz-covariant chiral particle action. Lagrangians for (1,1), (1,0), (0,1) chiral superparticles (CSP) invariant under the local Siegel-type transformations are considered; the mechanism of closing of local Siegel k-symmetry algebra in Lagrangian formulation for the (1,0) CSP is suggested. The full set of (1,0) supergravity constraints is obtained from the requirement of preserving local symmetries in a curved background. The possibility of extending the results to D=10 case is discussed.
TWO-DIMENSIONAL QUANTUM GRAVITY, MATRIX MODELS AND STRING THEORY
Authors: DEMETERFI KREŠIMIR
Published: November 2004

We review some results of the recent progress in understanding two-dimensional quantum gravity and low-dimensional string theories based on the lattice approach. The possibility to solve the lattice models exactly comes from their equivalence to large N matrix models. We describe various matrix models and their continuum limits, and discuss in some detail the phase structure of Hermitian one-matrix models. For the one-dimensional matrix model we discuss its field theoretic formulation through a collective field method and summarize some perturbative results. We compare the results obtained from matrix models to the results in the continuum approach to string theory.
TOPOLOGICAL SOLITON MULTIPLETS IN (4+1)-DIMENSIONAL YMCS THEORY
Authors: AULAKH C.S. , SONI V.
Published: November 2004

We generalize our results1 on charged topological solitons (CTS’s) in (4+1)-dimensional SU (3) Yang-Mills-Chern-Simons (YMCS) theory to SU (N). The SU (N) multiplet structure of two classes of solitons associated with the maximal embeddings SU (2)× U (1)N−2 ⊂ SU (N) and SO (3)× U (1)N−3⊂ SU (N) and the vital role of the SU (N) multiplet of topological currents are clarified. In the case of the first embedding, one obtains a NC2-plet of CTS’s. In the second, for N=3, one obtains neutral solitons which, though (classically) spinless, have magnetic moments. For N≥4, after modding out the above-mentioned nonparticulate feature, one obtains NC3-plets of CTS’s.
CHAOS IN ABELIAN AND NON-ABELIAN HIGGS SYSTEMS
Authors: DEY B. , KUMAR C.N. , SEN A.
Published: November 2004

The nonintegrability and chaotic nature of the Yang-Mills Higgs systems are considered. We have studied the Abelian Higgs model and the SO(3) Georgi-Glashow model (non-Abelian Higgs model), which possess vortices and monopole solutions respectively. The Painlevé analysis of the corresponding time-dependent equations of motion shows that both systems are nonintegrable for all choices of the parameter values. The Poincare surface-of-section plot shows the presence of chaotic trajectories in the phase space at certain parameter values for both systems. The chaotic nature of the trajectories is also indicated by the computations of the Lyapunov exponents of the corresponding systems.
COVARIANT VS. UNITARY QUANTIZATION: SUPERSYMMETRIC RECONCILIATION
Authors: ROZANSKY L.
Published: November 2004

A quantization of one-dimensional supergravity, which leads to a Dirac spin 1/2 particle, is considered. A propagator of this particle is calculated in the path integral formalism. A covariant procedure (which involves ghosts) is applied in the unitary gauge. We show that supersymmetry can remove the discrepancy between the covariant and unitary quantization procedure, which was discovered in Ref. 4 for the case of nonsupersymmetric gravitational theories.
INSTANTON-LIKE TRANSITIONS IN HIGH ENERGY COLLISIONS
Authors: TINYAKOV P. G.
Published: November 2004

In the framework of a systematic approach, the present status of the problem of instanton-like transitions in high energy particle collisions is reviewed. The arguments in favor of the exponential form of the total two-particle cross section in the one-instanton sector, exp [1/g2F(E/E sph )], are summarized. The perturbative technique for the evaluation of the function F(E/E sph ) is considered in detail. The nonperturbative semiclassical approach to the evaluation of F(E/E sph ), which may provide a reasonable basis for the numerical study of the problem, is discussed.
TORSION AND SPONTANEOUS COMPACTIFICATION
Authors: RICHTER O. , RUDOLPH G.
Published: November 2004

Spontaneous compactification of Einstein–Cartan theory with quadratic Gauß–Bonnet term is investigated. For the homogeneous spaces SU (3)/ U (1) × U (1), Sp (2)/ SU (2) × U (1) and G2/ SU (3) we find the most general form of G-invariant metric and torsion and find solutions of spontaneous compactifying type. It turns out that these solutions admit a geometrical interpretation.
REIDEMEISTER TORSION AND SIMPLICIAL QUANTUM GRAVITY
Authors: CARFORA M. , MARZUOLI A.
Published: November 2004

We show that three-dimensional simplicial quantum gravity, as described by dynamically triangulated manifolds, is connected with a Gaussian model determined by the simple homotopy types of the underlying manifolds.

By exploiting this result it is shown that the partition function of three-dimensional simplicial quantum gravity is well defined in a convex region in the plane of the gravitational and cosmological coupling constants. Such a region is determined by the Reidemeister–Franz torsion invariants associated with orthogonal representations of the fundamental groups of the set of manifolds considered. The system shows a critical behavior and undergoes a first order phase transition at a well-defined value of the couplings, again determined by the torsion invariants. On the critical line the partition function can be explicitly related to a Gaussian measure on the general linear group GL (∞, R), showing evidence of a well-defined thermodynamical limit of the theory, with a stable (vacuum) configuration corresponding to three-dimensional (homology) manifolds. The first order nature of the transition yielding such a configuration seems to support the belief in the absence of a continuum limit of the theory. More generally, the approach presented here provides further analytical support for the picture of three-dimensional simplicial quantum gravity which has been abstracted from numerical simulations.
STRUCTURE OF EFFECTIVE FERMION MODELS IN SYMMETRY-BREAKING PHASE
Authors: ANDRIANOV A. A. , ANDRIANOV V. A.
Published: November 2004

We describe the structure of models with effective many-fermion interaction and a finite cutoff in the symmetry-breaking regime. The large-Nc tadpole mechanism for the DSB and the fine-tuning condition in providing the scale invariance are used to classify the set of quasilocal vertices relevant for the dynamic mass formation. It is found that in such effective models the vertices with four, six and eight fermions only should be retained in four-dimensional space.
NEW RESULTS ON HADRON PRODUCTION IN DEEP-INELASTIC LEPTON SCATTERING
Authors: SCHMITZ NORBERT
Published: November 2004

New experimental results on the production of hadrons in deep-inelastic lepton–nucleon and lepton–nucleus collisions are reviewed. The following topics are covered: multiplicities, nuclear effects, intermittency, Bose–Einstein correlations, and production of neutral strange particles.
TOP CONDENSATES AS HIGGS SUBSTITUTE
Authors: LINDNER MANFRED
Published: November 2004

We review developments in top condensation starting from the first example which was a simple effective Nambu–Jona-Lasinio (NJL) model. The connection between the underlying four-fermion interaction and the structure of the composite Higgs sector is generalized to obtain the scalar sectors of a number of Standard Model extensions dynamically from some NJL model, as well as to include possible radial and spin excitations of the Higgs sector. In all these NJL models the symmetries do not forbid further higher dimensional four-fermion operators. If such operators could have arbitrary strength then this would result in arbitrary Higgs and top mass predictions. The nonrenormalizable NJL model is however thought to be only an effective description of some fully consistent theory where higher dimensional operators are not free parameters so that the corresponding four-fermion operators are restricted. We discuss renormalizable gauge theories of top condensation where this is the case. These models are therefore predictive and do not lead to arbitrary predictions.
DOUBLE SCALING LIMIT OF THE SUPER-VIRASORO CONSTRAINTS
Authors: ALVAREZ-GAUMÉ L. , BECKER K. , BECKER M. , EMPARAN R. , MAÑES J.
Published: November 2004

We obtain the double scaling limit of a set of superloop equations recently proposed to describe the coupling of two-dimensional supergravity to minimal superconformal matter of type (2,4m). The continuum loop equations are described in terms of a [Formula: see text] theory with a Z2-twisted scalar field and a Weyl–Majorana fermion in the Ramond sector. We have computed correlation functions in genus zero, one and partially in genus two. An integrable supersymmetric hierarchy describing our model has not yet been found. We present a heuristic argument showing that the purely bosonic part of our model is described by the KdV hierarchy.
GRAVITATIONAL INSTANTONS IN HETEROTIC STRING THEORY: THE H-MAP AND THE MODULI DEFORMATIONS OF (4,4) SUPERCONFORMAL THEORIES
Authors: BILLÓ MARCO , FRÈ PIETRO , ZAFFARONI ALBERTO , GIRARDELLO LUCIANO
Published: November 2004

We study the problem of string propagation in a general instanton background for the case of the complete heterotic superstring. We define the concept of generalized hyper-Kähler manifolds and we relate it to (4,4) superconformal theories. We propose a generalized h-map construction that predicts a universal SU (6) symmetry for the modes of the string excitations moving in an instanton background. We also discuss the role of abstract N = 4 moduli and, applying it to the particular limit case of the solvable SU (2) × R instanton found by Callan et al., we show that it admits deformations and corresponds to a point in a 16-dimensional moduli space. The geometrical characterization of the other spaces in the same moduli space remains an open problem.
ALGORITHM FOR COMPUTING THE β FUNCTION OF QUANTUM ELECTRODYNAMICS IN THE LARGE Nf EXPANSION
Authors: GRACEY J. A.
Published: November 2004

By considering corrections to the asymptotic scaling functions of the photon and electron in quantum electrodynamics with Nf flavors, we solve the skeleton Dyson equations at O(1/Nf) in the large Nf expansion at the d-dimensional critical point of the theory and deduce the critical exponent β′(gc), in arbitrary dimensions, and subsequently present a method for computing higher order corrections to β(g).
RENORMALIZATION OF MICROPHASE SEPARATION FIELD THEORY
Authors: BENHAMOU MABROUK
Published: November 2004

This work is concerned with the renormalization of the field theory describing microphase separation, in diblock copolymers or in chemically crosslinked two-component networks. The present theory differs from the usual φ4-theory only by the form of the propagator: [Formula: see text], where "the square mass" m2 = χ0 − χ in the two cases, χ being the Flory interaction parameter and χ0 its critical value if the system is uncrosslinked. C is [Formula: see text] (the radius of gyration) for diblock copolymers or the elastic constant for the crosslinked two-component networks. We prove that this theory is renormalizable, and that the corresponding counterterms have the same form as those of the usual φ4-theory. A α-parametric representation is constructed for this theory, and the renormalization is described in this representation. Finally, we show that in dimensional regularization with the minimal subtraction scheme, the counterterms of the theory reduce to those of the usual one (in the same prescription).
SIX-LOOP DIVERGENCES IN THE SUPERSYMMETRIC KÄHLER SIGMA MODEL
Authors: JACK I. , JONES D. R. T. , PANVEL J.
Published: November 2004

The supersymmetric σ model on a Kähler manifold has a nonvanishing β function at four loops, but the β function at five loops can be made to vanish by a specific choice of renormalization scheme. We investigate whether this phenomenon persists at six loops, and conclude that it does not; there is a nonvanishing six-loop β function irrespective of renormalization scheme ambiguities.
NONLINEAR QUANTUM MECHANICS WITH NONCLASSICAL GRAVITATIONAL SELF-INTERACTION III: RELATED TOPICS
Authors: POPOVA A. D. , PETROV A. N.
Published: November 2004

Some problems are considered in the framework of general quantum mechanics with gravitational self-interaction constructed earlier. A number of them were analyzed for the stationary situation. Here, the problem of gauge invariance generated by translations which do not violate the 3 + 1 splitting is studied. The notions of position and momentum operators are extended to the general case. The uncertainty relations are obtained for the uncertainty of the Ricci tensor and for uncertainties of the position and momentum of a particle. The correspondence between the stationary and nonstationary cases is examined at the level of variational principles. At least, the one-particle and two-particle problems in the Newtonian–Schrödingerian limit are considered; the latter problem is compared with the standard two-particle quantum problem to demonstrate the advantage of our approach.
PERTURBATIVE APPROACH TO 2D QUANTUM GRAVITY
Authors: ICHINOSE SHOICHI
Published: November 2004

Local properties of Polyakov's 2D quantum gravity are closely analyzed in the perturbative way with respect to the gravitational coupling (loop expansion). The 2D general coordinate invariance of the effective action is preserved using the background field method. Its renormalizability and conformal invariance are shown. The renormalization of the gravitational coupling and redefinition of the metric (gravitational) field are explicitly done at the one-loop order. As for the case of adding the cosmological term, the renormalization of the cosmological constant and the area constant is analyzed. A new standpoint on the metric field redefinition is proposed. The generalized renormalization group function for the metric field, in addition to the usual one for the coupling, is explicitly obtained at the one-loop order. Comparison with 2D WZNW theory and with the ordinary (4D) pure quantum gravity is made.
NONDIAGONAL CPm COSET MODELS AND THEIR POINCARÉ POLYNOMIALS
Authors: ALDAZABAL G. , ALLEKOTTE I. , ANDRÉS E. , NÚÑEZ C.
Published: November 2004

N = 2 coset models of the type SU (m + 1)/ SU (m) × U (1) with nondiagonal modular invariants for both SU (m + 1) and SU (m) are considered. Poincaré polynomials of the the number of chiral generations of the associated string compactifications. Moddings corresponding chiral rings of these algebras are constructed. They are used to compute the number of chiral generations of the associated string compactifications. Moddings by discrete symmietries are also discussed.
WIGHTMAN FUNCTIONS IN THE COVARIANT OPERATOR FORMALISM AND THE OSTENDORF RULES
Authors: ABE MITSUO
Published: November 2004

The Ostendorf rules, which generalize Feynman rules for τ functions to Wightman functions, are discussed in the light of the consistency with the operator solution and the energy-positivity condition (or the spectral condition). For the exactly solvable model called the one-loop model, it is shown that the Ostendorf rules are strictly justified.
CHIRAL PERTURBATION THEORY AND ANOMALOUS PROCESSES
Authors: BIJNENS JOHAN
Published: November 2004

The application of chiral perturbation theory to low energy processes of abnormal intrinsic parity (anomalous) is discussed. The full infinite part at next-to-leading order is calculated. Estimates of the finite part of the effective Lagrangian from vector meson dominance and the chiral constituent quark model are obtained. This is then applied to decays of pseudoscalars to photon–photon and photon–three-pseudoscalar couplings.
ON THE CONTINUUM LIMIT OF THE CONFORMAL MATRIX MODELS
Authors: MIRONOV A. , PAKULIAK S.
Published: November 2004

The double scaling limit of a new class of the multi-matrix models proposed in Ref. 1, which possess the W-symmetry at the discrete level, is investigated in detail. These models are demonstrated to fall into the same universality class as the standard multi-matrix models. In particular, the transformation of the W-algebra at the discrete level into the continuum one of the papers2 is proposed and the corresponding partition functions compared. All calculations are demonstrated in full in the first nontrivial case of W(3)-constraints.
q-DEFORMED LATTICE GAUGE THEORY AND 3-MANIFOLD INVARIANTS
Authors: BOULATOV D. V.
Published: November 2004

The notion of q-deformed lattice gauge theory is introduced. If the deformation parameter is a root of unity, the weak coupling limit of a 3-d partition function gives a topological invariant of a corresponding 3-manifold. It enables us to define the generalized Turaev–Viro invariant for cell complexes. It is shown that this invariant is determined by an action of a fundamental group on a universal covering of a complex. A connection with invariants of framed links in a manifold is also explored. A model giving a generating function of all simplicial complexes weighted with the invariant is investigated.
ON THE STRING EQUATION AND THE WHITHAM METHOD
Authors: FUCITO F. , GAMBA A. , MARTELLINI M.
Published: November 2004

We present a detailed report of the application of the Whitham method to the study of the string equation. Even though the solutions obtained with this method are not exact they are in excellent agreement with the true solutions, as we explicitly show using numerical simulations.
THE PROBLEM OF BOSONIZATION OF LOCAL FOUR-QUARK OPERATORS
Authors: IVANOV A. N. , TROITSKAYA N. I. , NAGY M.
Published: November 2004

The problem of bosonization of standard local four-quark operators, by involving the penguin operator, with ΔI = 1/2 and ΔS = 1 selection rules, is studied. We show that the well-known Cronin's operator determined within the effective chiral Lagrangian approach with nonlinear realization of chiral SU (3) × SU (3) symmetry (so-called chiral perturbation theory at the hadronic level) can realize the hadronic level description of local four-quark operators with (V − A) × (V − A) quark structure only. Also, it is shown that any attempts to apply Cronin's operator for bosonization of the penguin operator, possessing (V − A) × (V + A) quark structure, are doomed to failure. The latter is explained by the inability of Cronin's operator to describe correctly the s-wave final-state interaction, which is very important for transitions governed by the penguin operator. The asymmetry of quark condensate is calculated. The sign of this asymmetry is opposite to that one assumed in the framework of QCD sum rules.
THE LAX OPERATOR APPROACH FOR THE VIRASORO AND THE W-CONSTRAINTS IN THE GENERALIZED KdV HIERARCHY
Authors: PANDA SUDHAKAR , ROY SHIBAJI
Published: November 2004

We show directly in the Lax operator approach how the Virasoro and W-constraints on the τ-function arise in the p-reduced KP hierarchy or generalized KdV hierarchy. In particular, we consider the KdV and the Boussinesq hierarchy to show that the Virasoro and the W-constraints follow from the string equation by expanding the "additional symmetry" operator in terms of the Lax operator. We also mention how this method could be generalized for higher KdV hierarchies.
HEISENBERG QUANTIZATION FOR SYSTEMS OF IDENTICAL PARTICLES
Authors: LEINAAS JON MAGNE , MYRHEIM JAN
Published: November 2004

We show that the algebraic quantization method of Heisenberg and the analytical method of Schrödinger are not necessarily equivalent when applied to systems of identical particles. Heisenberg quantization is a natural approach, but inherently more ambiguous and difficult than Schrödinger quantization. We apply the Heisenberg method to the examples of two identical particles in one and two dimensions, and relate the results to the so-called fractional statistics known from Schrödinger quantization. For two particles in d dimensions we look for linear, Hermitian representations of the symplectic Lie algebra sp(d, R). The boson and fermion representations are special cases, but there exist other representations. In one dimension there is a continuous interpolation between boson and fermion systems, different from the interpolation found in Schrödinger quantization. In two dimensions we find representations that can be realized in terms of multicomponent wave functions on a three-dimensional space, but we have no clear physical interpretation of these representations, which include extra degrees of freedom compared to the classical system.
THE FREE FIELD REPRESENTATION OF SU(3) CONFORMAL FIELD THEORY
Authors: TOOMASSIAN HOVIK D.
Published: November 2004

The structure of the free field representation and some four-point correlation functions of the SU(3) conformal field theory are considered.
CHARACTERS FOR COSET CONFORMAL FIELD THEORIES AND MAVERICK EXAMPLES
Authors: DUNBAR DAVID C. , JOSHI KEITH G.
Published: November 2004

We present an example of a coset conformal field theory which cannot be described by the identification current method. To study such examples we determine formulae for the characters of coset conformal field theories.
EARLY TIME DEPARTURES FROM THE WEISSKOPF-WIGNER DECAY RATE
Authors: URBANOWSKI K. , SKOREK J.
Published: November 2004

The problem of the early time decay rate is studied using the equation for a projection of a state vector. Formulas are found for the decay rate γ(t), generally depending on time, and for early time departures of γ(t) from a rate γ0, given by Weisskopf-Wigner approximation. It is shown that γ(t)→0 as t→0, and γ(t)→γ0 as t→∞. The dependence γ(t) on t is studied numerically in some models.
FEYNMAN AND THE QUARK MODEL
Authors: RAVNDAL F.
Published: November 2004

As a student and later research fellow working with Richard Feynman at Caltech in the period 1969–74, I was in the happy situation of getting him interested in the quark model. This resulted in the construction of the relativistic harmonic oscillator quark model with the proviso of involving as few parameters and ad hoc assumptions as possible. The detailed predictions of the model and in particular for the nucleon photoproduction amplitudes were so good that in Feynman’s mind the quarks were to be considered real particles and identified by the partons seen in deep inelastic scattering. This article is a short account of my part in those developments and my collaboration with Feynman.
GENERAL CONSTRUCTION OF PHYSICAL STATES IN 2D QUANTUM GRAVITY
Authors: HOSONO SHINOBU , TSUJIMARU SHO
Published: November 2004

The BRST cohomology of two-dimensional gravity coupled to 0≤c<1 minimal conformal matter is investigated in the conformal gauge. We formulate a general procedure to write down the physical states via the technique of spectral sequences. Paying attention to the ghost sectors, we show that the physical states correspond to the microscopic loops, and the macroscopic loops are described by b-ghosts and c-ghosts respectively. For pure gravity, several physical states are first calculated explicitly and, in addition, the general formula for macroscopic loops is obtained by relating it to a simpler Lie algebra cohomology. We also discuss the local operator algebras of microscopic loops in Liouville theory, the so-called ground ring, in the relation to those from the Schwinger-Dyson equation in the matrix model.
PION PRODUCTION DIFFERENTIAL CROSS SECTION OF HEAVY ION COLLISIONS AT SUBTHRESHOLD ENERGIES
Authors: ABUMURAD K.M.
Published: November 2004

The Lorentz-invariant differential cross section (LIDCS) for π production in heavy ion collisions was studied through the two-step process, NN→NΔ→NNπ. A phenomenological interaction potential containing central and tensor terms was used. The effect of inclusion of the tensor term on the LIDCS was little. The target nucleus 12C was excited to one of its giant resonance states, Jπ=1+, T=1, while the projectile nucleus 16O was excited to an isobar Δ (M=1232 MeV , ΓΔ=115.11 MeV ) which decayed (NΔ→NNπ), giving a nucleon and a pion mπ=138 MeV . In comparison with available experimental data, the shape was reproduced, but the theoretical results were higher.
THE SOq(N, R)-SYMMETRIC HARMONIC OSCILLATOR ON THE QUANTUM EUCLIDEAN SPACE ${\bf R}_q^N$ AND ITS HILBERT SPACE STRUCTURE
Authors: FIORE GAETANO
Published: November 2004

We show that the isotropic harmonic oscillator in the ordinary Euclidean space RN (N≥3) admits a natural q-deformation into a new quantum-mechanical model having a q-deformed symmetry (in the sense of quantum groups), SO q(N, R). The q-deformation is the consequence of replacing RN by [Formula: see text] (the corresponding quantum space). This provides an example of quantum mechanics on a noncommutative geometrical space. To reach the goal, we also have to deal with a sensible definition of integration over [Formula: see text], which we use for the definition of the scalar product of states.
ON THE SPECTRA OF ${{\widehat{sl}\left( N \right)_k } \mathord{\left/ {\vphantom {{\widehat{sl}\left( N \right)_k } {\widehat{sl}\left( N \right)_k }}} \right. \kern-\nulldelimiterspace} {\widehat{sl}\left( N \right)_k }}$ AND WN GRAVITIES
Authors: SADOV VLADIMIR
Published: November 2004

We study the spectra of G/G coset models by computing BRST cohomology of affine Lie algebras with coefficients in tensor product of two modules. One-to-one correspondence between the spectra of [Formula: see text] and that of the minimal matter coupled to gravity (including boundary states of the Kac table) is observed. This phenomenon is discussed from the point of Hamiltonian reduction of BRST complexes of [Formula: see text] Lie algebras.
THEORETICAL ASPECTS OF THE POLARIZABILITY OF THE NUCLEON
Authors: L’VOV A.I.
Published: November 2004

Two aspects of the nucleon electromagnetic polarizabilities, αN and βN, are discussed. The first one is the interrelation between static and Compton polarizabilities. Relativistically consistent treatment of the polarization effects based on effective Lagrangians results in the conclusion that the Compton polarizabilities, rather than the static ones, drive the energy shift of the nucleon in external fields. The cluster substructure of the static polarizabilities is shown to be crucial for consistent calculations of the polarizabilities. The second aspect concerns the dominant role of pion degrees of freedom in αN as seen through dispersion relations, chiral perturbation theory, and constituent models. The reported calculations of αN within soliton models are shown to be inconsistent with gauge invariance. The difficulties in explaining the observed large diamagnetic component of βN are emphasized.
THE SPINNING CONFORMAL PARTICLE AND ITS BRST QUANTIZATION
Authors: MÅRTENSSON ULF
Published: November 2004

We present the classical and quantum theory of the spinning conformal particle. This is a model with manifestly O(2, 4) (conformal) invariance, and it describes both massive and massless particles of arbitrary spin depending on the projection to Minkowski space. We perform both an ordinary BRST quantization and an extended one including the anti-BRST symmetry. It is shown that anti-BRST invariance is necessary to ensure ghost decoupling and make the quantization of the model consistent.
INFRARED EVOLUTION EQUATION FOR BACKWARD QUARK-GLUON SCATTERING
Authors: CHIAPPETTA P. , ERMOLAEV B.I.
Published: November 2004

The infrared evolution equation is used to compute in the double logarithmic approximation the inelastic contribution to inclusive gluon production from backward quark-gluon scattering.
INTRODUCTION TO THERMAL FIELD THEORY
Authors: ALTHERR T.
Published: November 2004

This is a very basic introduction and short (and of course incomplete) overview of thermal field theory. In the first part, I introduce the thermal propagator at a very simple level and give the Feynman rules using the time-path contour method. In the second part, I give examples of these rules in scalar theory and discuss the origin of the thermal mass and other important effects as infrared divergences and phase transitions. In the third part, I outline the resummation program of Braaten and Pisarski.
ELECTRONIC POLARON EFFECTS IN MIXED VALENCE AND HEAVY FERMION MATERIALS
Authors: LIU S. H.
Published: November 2004

It is shown that the Coulomb interaction between f electrons and broad band electrons has a profound influence on the dynamical properties of an f hole in mixed valence and heavy fermion materials. At zero temperature the dynamics of the screening process contains an infrared divergence. The broadening of this divergence by temperature causes the motion of the f electrons to crossover from wave propagation to diffusion. This mechanism explains the observed dual nature of the f electrons, namely that at low temperatures they behave like a Fermi liquid, while at high temperatures they evolve into a lattice of localized magnetic moments.
CRYSTALLINE ELECTRIC FIELD EFFECTS IN UPd2Al3
Authors: BÖHM A. , GRAUEL A. , SATO N. , SCHANK C. , GEIBEL C. , KOMATSUBARA T. , WEBER G. , STEGLICH F.
Published: November 2004

The temperature dependencies of the specific heat and the anisotropic magnetic susceptibility of the heavy-fermion superconductor UPd 2 Al 3 show distinct anomalies which can be described by a crystalline electric field (CEF) model for Uranium with hexagonal site symmetry. We find that a CEF-level scheme for the 3 H 4 multiplet ( 5f 2 configuration) implying two low lying singlets surprisingly well fits the experimental results.
SPECIFIC HEAT OF UPd2Al3
Authors: RADWAŃSKI R. J. , FRANSE J. J. M.
Published: November 2004

Particularities in the specific heat of UPd 2 Al 3, a λ-type of peak with a maximum at 14.5 K and a Schottky-type of peak with a broad maximum at 55 K, has been attributed to the 5f-subsystem of the U atoms. The U-5f contribution has been found to be described surprisingly well within a single-ion Hamiltonian that includes the charge multipolar (CMP) interactions and the antiferromagnetic (AF) exchange interaction between the U 3+ ions. The AF exchange parameter and the full set of the CMP parameters associated with the hexagonal symmetry have been evaluated. The energy-level scheme (ELS) of this Kramers ion is constructed. The ground-state function Γ8 of the 5f 3 electrons is highly anisotropic. This state results from higher-order charge multipolar interactions. Magnetic properties resulting from this scheme including the metamagnetic-like transition at 18 T, the strongly-reduced value for the U-ion moment and its field dependence are found to be in good agreement with experimental observations.
PRESSURE STUDIES ON THE MAGNETIC PHASE TRANSITION OF THE HEAVY FERMION COMPOUND Ce(Cu1−xNix)2Ge2
Authors: SPARN G. , BEYERMANN W. P. , CANFIELD P. C. , FISK Z. , THOMPSON J. D. , STEGLICH F.
Published: November 2004

Hydrostatic pressure experiments on single crystals of the magnetically ordered heavy fermion compound CeCu 2 Ge 2 for P > 0.1 GPa revealed a pressure dependence of the magnetic ordering temperature ( dT N / dP = −0.1 K/GPa ), which can be brought into quantitative agreement with theoretical calculations. The results are suitable to explain a difference observed between the magnetic phase diagram of Ce ( Cu 1− x Ni x )2 Ge 2 and the calculated dependence of T N on the local exchange coupling constant g.
MAGNETIC PROPERTIES OF HEAVY FERMION SEMI-CONDUCTORS
Authors: RISEBOROUGH PETER S.
Published: November 2004

The heavy fermion semi-conductors, such as Ce 3 Bi 4 Pt 3 or CeNiSn, are modeled by the Anderson Lattice Hamiltonian. In the limit of large coulomb interaction, the strong electron-electron correlations can be re-expressed in terms of slave bosons. The resulting model is treated in the mean field approximation. In this approximation, the model exhibits a transition between a low temperature semi-conducting state and a high temperature state. The high temperature state may be characterized as having an uncorrelated metallic conduction band and a set of independent local moments, whereas the low temperature state can be described as a highly correlated indirect gap semi-conductor. The dynamic magnetic response function is calculated, for the low temperature phase.