bluuebunny/crossref_metadata_2025 huggingface dataset:
FERMION QUANTUM FIELD THEORY WITH A NEW GAUGE SYMMETRY, RELATED TO A PSEUDOSCALAR-CONSERVED-CHARGE VARIETY
Authors: ZIINO G.
Published: October 2004

Massive chiral fields, “left-handed” for fermions and “right-handed” for antifermions, are shown to be a natural prediction of a new approach to the Dirac field theory which in the zero-mass limit spontaneously yields Weyl’s two-component scheme. Such an approach gives an improved theoretical framework to the “standard model”: It accounts for (and clarifies the origin of) the “P-violation” effect, without needing any ad-hoc external prescriptions. A double-faced—either “Dirac” or “chiral” — model of a massive spin[Formula: see text] fermion is involved, due to the internal coexistence of two anticommuting—scalar and pseudoscalar—varieties of charges, the former being responsible for “P-conserving” processes and the latter for “P-violating” ones. The resulting scheme, besides naturally embodying the P-violation effect, leads paradoxically to a retrieval of parity symmetry itself: owing to the anticommutivity property of the above coexisting charge varieties, a chiral fermion is predicted to be the same as a mere pseudoscalar-charge particle, and the ordinary CP mirror image of the weak-isospin fermionic current may now become the true P mirror image of it. On these grounds a suitable generalized field formalism is built, which turns out to be endowed also with chiral gauge invariance, in spite of the presence of mass. Such novel global gauge symmetry is shown to express pseudoscalar-charge conservation; its local extension is seen to yield a “minimal” coupling, which could in particular apply to magnetic-monopole dynamics.
THE FIVE-DIMENSIONAL KEPLER PROBLEM AS AN SU(2) GAUGE SYSTEM: ALGEBRAIC CONSTRAINT QUANTIZATION
Authors: TRUNK MICHAEL
Published: October 2004

Starting from the structural similarity between the quantum theory of gauge systems and that of the Kepler problem, an SU(2) gauge description of the five-dimensional Kepler problem is given. This non-Abelian gauge system is used as a testing ground for the application of an algebraic constraint quantization scheme which can be formulated entirely in terms of observable quantities. For the quantum-mechanical reduction, only the quadratic Casimir of the constraint algebra, interpreted as an observable, is needed.
HIERARCHICAL SUPERSYMMETRY BREAKING IN SUPERSTRING-DERIVED STANDARD-LIKE MODELS
Authors: FARAGGI ALON E. , HALYO EDI
Published: October 2004

We examine the problem of supersymmetry breaking in realistic superstring standard-like models which are constructed in the free-fermionic formulation. We impose a supersymmetric vacuum at the Planck scale by requiring vanishing F and D constraints at the cubic level of the superpotential. We then study possible scenarios for supersymmetry breaking by examining the role of nonrenormalizable terms and hidden sector gaugino and matter condensates. We argue that in some scenarios hierarchical supersymmetry breaking in the observable sector is possible.
THE BRST SYMMETRY OF AFFINE LIE SUPERALGEBRAS AND NONCRITICAL STRINGS
Authors: ENNES I.P. , RAMALLO A.V. , ISIDRO J.M.
Published: October 2004

The topological field theories associated with affine Lie superalgebras are constructed. Their BRST symmetry is characterized by a Kazama algebra containing spin 1, 2 and 3 operators and closes linearly. Under this symmetry all operators are grouped into BRST doublets. The relation between the models constructed and noncritical string theories is explored.
HEAVY QUARKONIUM IN THE DUAL GINZBURG–LANDAU THEORY OF QCD
Authors: SUZUKI KATSUHIKO , TOKI HIROSHI
Published: October 2004

We study the masses and leptonic decay widths of the heavy quarkonium in the dual Ginzburg–Landau (DGL) theory of QCD, in which the Abelian monopole condensation plays an essential role for color confinement. The effect of color screening due to the light quark pair creation is introduced by the infrared momentum cutoff in the gluon propagator. We find that the color screening effect is important for reproducing the properties of the heavy quarkonium, in particular the leptonic decay width. We also discuss the underlying systematics of the heavy quark spectroscopy in the DGL theory.
BRST–BFV QUANTIZATION AND THE SCHWINGER ACTION PRINCIPLE
Authors: GARCIA J. ANTONIO , VERGARA J. DAVID , URRUTIA LUIS F.
Published: October 2004

We introduce an operator version of the BRST–BFV effective action for arbitrary systems with first class constraints. Using the Schwinger action principle we calculate the propagators corresponding to: (i) the parametrized nonrelativistic free particle, (ii) the relativistic free particle and (iii) the spinning relativistic free particle. Our calculation correctly imposes the BRST invariance at the end points. The precise use of the additional boundary terms required in the description of fermionic variables is incorporated.
GRAVITATIONAL INSTANTONS IN ASHTEKAR’S FORMALISM
Authors: ISHIHARA HIDEKI , KUBOTANI HIROTO , FUKUYAMA TAKESHI
Published: October 2004

Gravitational instantons of Bianchi type IX space are constructed in Ashtekar’s canonical formalism. Instead of solving the self-duality condition, we fully solve the constraint on the “initial surface” and “Hamiltonian equations.” This formalism is applicable to the matter coupled system with cosmological constant.
WAVE FUNCTIONALS, HAMILTONIANS AND THE RENORMALIZATION GROUP
Authors: MINIC D. , NAIR V.P.
Published: October 2004

We analyze the renormalization of wave functionals and energy eigenvalues in field theory. A general discussion of the canonical structure of the renormalization group equation is also given.
THE SUPERCURRENT IN SUPERSYMMETRIC FIELD THEORIES
Authors: CLARK T.E. , LOVE S.T.
Published: October 2004

A supercurrent superfield whose components include a conserved energy-momentum tensor and supersymmetry current as well as an (generally broken) R symmetry current is constructed for a generic effective N=1 supersymmetric gauge theory. The general form of the R symmetry breaking is isolated. Included within the various special cases considered is the identification of those models which exhibit an unbroken R symmetry. One such example corresponds to a nonlinearly realized gauge symmetry where the chiral field R weight is required to vanish.
NONPOLYNOMIAL REALIZATIONS OF ${\mathcal W}$ ALGEBRAS
Authors: BARBARIN F. , RAGOUCY E. , SORBA P.
Published: October 2004

Relaxing first-class constraint conditions in the usual Drinfeld—Sokolov Hamiltonian reduction leads, after symmetry fixing, to realizations of [Formula: see text] algebras expressed in terms of all the J current components.

General results are given for [Formula: see text] a nonexceptional simple (finite and affine) algebra. Such calculations directly provide the commutant, in the (closure of) [Formula: see text] enveloping algebra, of the nilpotent subalgebra [Formula: see text], where the subscript refers to the chosen gradation in [Formula: see text]. In the affine case, explicit expressions are presented for the Virasoro, [Formula: see text], and Bershadsky algebras at the quantum level.
CONNECTION BETWEEN ζ AND CUTOFF REGULARIZATIONS OF CASIMIR ENERGIES
Authors: BENEVENTANO C.G. , SANTANGELO E.M.
Published: October 2004

We study the connection between ζ- and cutoff-regularized Casimir energies for scalar fields. We show that, in general, both regularization schemes lead to divergent contributions, and to minimal finite parts which do not coincide. We determine the relationships among the various coefficients appearing in one approach and the other. We discuss the agreement with our predictions in the case of scalar fields in d-dimensional boxes under periodic boundary conditions. Finally, we apply our results to massless scalar fields in balls, an example where ambiguities remain under the physical prescriptions usually imposed to extract a finite result.
THE PROPER TIME EQUATION AND THE ZAMOLODCHIKOV METRIC
Authors: SATHIAPALAN B.
Published: October 2004

The connection between the proper time equation and the Zamolodchikov metric is discussed. The connection is twofold. First, as already known, the proper time equation is the product of the Zamolodchikov metric and the renormalization group beta function. Second, the condition that the two-point function is the Zamolodchikov metric implies the proper time equation. We study the massless vector of the open string in detail. In the exactly calculable case of a uniform electromagnetic field strength we recover the Born-Infeld equation. We describe the systematics of the perturbative evaluation of the gauge-invariant proper time equation for the massless vector field. The method is valid for nonuniform fields and gives results that are exact to all orders in derivatives. As a nontrivial check, we show that in the limit of uniform fields it reproduces the lowest order Born-Infeld equation.
AXIAL-SCHWINGER MODEL
Authors: AMORIM R. , BARCELOS-NETO J. , DUTRA A. DE SOUZA
Published: October 2004

We consider an extension of the axial model where local gauge symmetries are taken into account. The result is a mixing of the axial and Schwinger models. The anomaly of the axial current is calculated by means of the Fujikawa path integral technique and the model is also solved. Besides the well-known features of the particular models (axial and Schwinger) an effective interaction of scalar and gauge fields via a topological current is obtained. This term is responsible for the appearance of massive poles in the propagators that are different from those of both models.
PARABOSE-PARAFERMI SUPERSYMMETRY
Authors: MOSTAFAZADEH ALI
Published: October 2004

The (p=2) parabose–parafermi supersymmetry is studied in general terms. It is shown that the algebraic structure of the (p=2) parastatistical dynamical variables allows for (symmetry) transformations which mix the parabose and parafermi coordinate variables. The example of a simple parabose-parafermi oscillator is discussed and its symmetries investigated. It turns out that this oscillator possesses two parabose-parafermi supersymmetries. The combined set of generators of the symmetries forms the algebra of supersymmetric quantum mechanics supplemented with an additional central charge. In this sense there is no relation between the parabose–parafermi supersymmetry and the parasupersymmetric quantum mechanics. A precise definition of a quantum system involving this type of parabose-parafermi supersymmetry is offered, thus introducing (p=2) supersymmetric paraquantum mechanics. The spectrum degeneracy structure of general (p=2) supersymmetric paraquantum mechanics is analyzed in detail. The energy eigenvalues and eigenvectors for the parabose–parafermi oscillator are then obtained explicitly. The latter confirms the validity of the results obtained for general supersymmetric paraquantum mechanics.
THE ISSUE OF TIME EVOLUTION IN QUANTUM GRAVITY
Authors: KHEYFETS ARKADY , HOLZ DANIEL E. , MILLER WARNER A.
Published: October 2004

We discuss the relation between the concept of time and the dynamic structure of quantum gravity. We briefly review the problems of time associated with the standard procedures of gravity quantization. By explicitly utilizing York’s analysis of the geometrodynamic degrees of freedom, and imposing the constraints as expectation value equations, we describe a new procedure of gravity quantization. In particular, this “minimally constrained canonical” quantization procedure leads to a linear Schrödinger equation augmented by the super-Hamiltonian and supermomentum constraints imposed on expectation values. This approach supplies a description of time evolution in quantum geometrodynamics free from the standard problems of time associated with canonical approaches. Furthermore, the theory is applicable to the full theory of general relativity, without the need to impose symmetries or reduce dimensionality. Using this method we arrive at an analytic expression for the quantum evolution of the Kasner cosmology, as well as a numerically generated solution of the quantized Taub model. The key new feature of this approach is that we impose the constraints weakly — instead of the quantum-mechanical wave function satisfying the constraints exactly, it need only satisfy them on average. Thus the constraints only constrain the observables.
IRREDUCIBLE GAUGE THEORIES IN THE FRAMEWORK OF THE Sp(2)-COVARIANT QUANTIZATION METHOD
Authors: LAVROV P.M. , MOSHIN P. YU. , RESHETNYAK A.A.
Published: October 2004

Irreducible gauge theories in both the Lagrangian and Hamiltonian versions of the Sp (2)-covariant quantization method are studied. Solutions to generating equations are obtained in the form of expansions in power series of ghost and auxiliary variables up to the third order inclusive.
NONLINEAR SIGMA MODELS ON A HALF PLANE
Authors: MOURAD M.F. , SASAKI R.
Published: October 2004

In the context of integrable field theory with boundary, the integrable nonlinear sigma models in two dimensions, for example the O(N), the principal chiral, the CPN−1 and the complex Grassmannian sigma models, are discussed on a half plane. In contrast to the well-known cases of sine-Gordon, nonlinear Schrödinger and affine Toda field theories, these nonlinear sigma models in two dimensions are not classically integrable if restricted on a half plane. It is shown that the infinite set of nonlocal charges characterizing the integrability on the whole plane is not conserved for the free (Neumann) boundary condition. If we require that these nonlocal charges be conserved, then the solutions become trivial.
GRAVITON MODE FUNCTION IN INFLATIONARY COSMOLOGY
Authors: NG KIN-WANG
Published: October 2004

We consider the production of gravitons in an inflationary cosmology by approximating each epoch of change in the equation of state as sudden, from which a simple analytic graviton mode function has been derived. We use this mode function to compute the graviton spectral energy density and the tensor-induced cosmic microwave background anisotropy. The results are then compared to the numerical calculations which incorporate a smooth radiation-matter phase transition. We find that the sudden approximation is a fairly good method when compared to the long wavelength approximation. Besides, in determining the frequency range and amplitude of the mode function, we introduce a preinflationary radiation-dominated epoch and use a physically sensible regularization method.
ON MATRIX KP AND SUPER-KP HIERARCHIES IN THE HOMOGENEOUS GRADING
Authors: TOPPAN F.
Published: October 2004

Constrained KP and super-KP hierarchies of integrable equations (generalized NLS hierarchies) are systematically produced through a Lie-algebraic AKS matrix framework associated with the homogeneous grading. The role played by different regular elements in defining the corresponding hierarchies is analyzed, as well as the symmetry properties under the Weyl group transformations. The coset structure of higher order Hamiltonian densities is proven.

For a generic Lie algebra the hierarchies considered here are integrable and essentially dependent on continuous free parameters. The bosonic hierarchies studied in Refs. 1 and 2 are obtained as special limit restrictions on Hermitian symmetric spaces.

In the supersymmetric case the homogeneous grading is introduced consistently by using alternating sums of bosons and fermions in the spectral parameter power series.

The bosonic hierarchies obtained from [Formula: see text] and the supersymmetric ones derived from the N=1 affinization of sl (2), sl (3) and osp (1|2) are explicitly constructed.

An unexpected result is found: only a restricted subclass of the sl (3) bosonic hierarchies can be supersymmetrically extended while preserving integrability.
ANYONS AS SPINNING PARTICLES
Authors: CORTÉS JOSÉ L. , PLYUSHCHAY MIKHAIL S.
Published: October 2004

A model-independent formulation of anyons as spinning particles is presented. The general properties of the classical theory of (2+1)-dimensional relativistic fractional spin particles and some properties of their quantum theory are investigated. The relationship between all the known approaches to anyons as spinning particles is established. Some widespread misleading notions on the general properties of (2+1)-dimensional anyons are removed.
SCALING RELATIONS IN THE PHENOMENOLOGY OF QCD SUM RULES FOR THE HEAVY QUARKONIUM
Authors: KISELEV V.V.
Published: October 2004

In the framework of a specific scheme of the QCD sum rules for S wave levels of the heavy quarkonium, we derive expressions relating the leptonic constants, the energetic density of quarkonium states and universal characteristics in the heavy quarkonium physics, such as the difference between the masses of heavy quark Q and meson [Formula: see text] and the number of heavy quarkonium levels below the threshold of [Formula: see text] decay.
EXACT, E=0, QUANTUM SOLUTIONS FOR GENERAL POWER-LAW POTENTIALS
Authors: DABOUL JAMIL , NIETO MICHAEL MARTIN
Published: October 2004

For zero energy, E=0, we derive exact, quantum solutions for all power-law potentials, V(r)=−γ/rν, with γ>0 and −∞<ν<∞. The solutions are, in general, Bessel functions of powers of r. For ν>2 and l≥1 the solutions are normalizable. Surprisingly, the solutions for ν<−2, which correspond to highly repulsive potentials, are also normalizable, for all l≥0. For these |ν|>2 the partial-wave Hamiltonians, Hl, have overcomplete sets of normalizable eigensolutions. We discuss how to obtain self-adjoint extensions of Hl such that the above E=0 solutions become included in their domains. When 2>ν≥−2 the E=0 solutions are not square-integrable. The ν=2 solutions are also unnormalizable, but are exceptional solutions. We also find that, by increasing the dimension of the Schrödinger equation beyond 4, an effective centrifugal barrier is created which is sufficient to cause binding when E=0 and ν>2, even for l=0. We discuss the physics of the above solutions and compare them to the corresponding classical solutions, which are derived elsewhere.
GEODESIC AND AUTOPARALLEL EQUATIONS OVER DIFFERENTIABLE MANIFOLDS
Authors: MANOFF S.
Published: October 2004

The notions of ordinary, covariant and Lie differentials are considered as operators over differentiable manifolds with different (not only by sign) contravariant and covariant affine connections and metric. The difference between the interpretations of the ordinary differential as a covariant basic vector field and as a component of a contravariant vector field is discussed. By means of the covariant metric and the ordinary differential the notion of the line element is introduced and the geodesic equation is obtained and compared with the autoparallel equation.
WILSON LOOPS IN 2D YANG-MILLS: EULER CHARACTERS AND LOOP EQUATIONS
Authors: RAMGOOLAM SANJAYE
Published: October 2004

We give a simple diagrammatic algorithm for writing the chiral large N expansion of intersecting Wilson loops in 2D SU(N) and U(N) Yang-Mills theory in terms of symmetric groups, generalizing the result of Gross and Taylor for partition functions. We prove that these expansions compute Euler characters of a space of branched covering maps from string worldsheets with boundaries. We prove that the Migdal-Makeenko equations hold for the chiral theory and show that they can be expressed as linear constraints on perturbations of the chiral YM 2 partition functions. We briefly discuss finite N, the nonchiral expansion, and higher-dimensional lattice models.
THE SPECTRUM AND CONFINEMENT FOR THE BETHE-SALPETER EQUATION
Authors: UMNIKOV A. YU. , KHANNA F.C.
Published: October 2004

The problem of calculating the mass spectrum of the two-body Bethe-Salpeter equation is studied with no reduction to the three-dimensional (“quasipotential”) equation. The method to find the ground state and excited states for a channel with any quantum numbers is presented. The problem of the confining interaction for the Bethe-Salpeter equation is discussed from the point of view of formal properties of the bound state spectrum, but with only inspiration from QCD. We study the kernel that is nonvanishing at large Euclidean intervals, i.e. RE→∞, which is constructed as a special limiting case of the sum of the covariant one-boson-exchange kernels. In the coordinate space this kernel is just a positive constant and corresponds to the kernel ∝ δ(kE) in the momentum space. When the usual attractive interaction is added, it is found that this kernel is similar in its effect to the nonrelativistic potential in coordinate space, V(r), with V(r→∞)→V∞. The positive real constant V∞ gives the scale that defines the limit of the bound state spectrum compared to the sum of the constituent masses, M < 2m+V∞. At the same time, the self-energy corrections remove the singularities from the propagators of the constituents, i.e. constituents do not propagate as free particles. The combination of these features of the solutions allows an interpretation of this type of interaction as a confining one. The illustrative analytical and numerical calculations are presented for a model of massive scalar particles with scalar interaction, i.e. the “massive Wick model.”
ELECTRIC-MAGNETIC DUALITY AND ITS STRINGY ORIGINS
Authors: DUFF M.J.
Published: October 2004

We review electric–magnetic duality in N=4 (and certain N=2) globally supersymmetric gauge theories and show how this duality, which relates strong to weak coupling, follows as a consequence of a string—string duality. Black holes, 11 dimensions and supermembranes also have a part to play in the big picture.
THERMODYNAMIC BETHE ANSATZ AND THREE-FOLD TRIANGULATIONS
Authors: GLIOZZI F. , TATEO R.
Published: October 2004

In the thermodynamic Bethe ansatz approach to 2D integrable, ADE-related quantum field theories, one derives a set of algebraic functional equations (a Y system) which play a prominent role. This set of equations is mapped onto the problem of finding finite triangulations of certain 3D manifolds. This mapping allows us to find a general explanation of the periodicity of the Y system. For the AN related theories, and more generally for the various restrictions of the fractionally supersymmetric sine—Gordon models, we find an explicit, surprisingly simple solution of such functional equations in terms of a single unknown function of the rapidity. The recently found dilogarithm functional equations associated to the Y system simply express the invariance of the volume of a manifold for deformations of its triangulations.
ON THE SINE-GORDON — THIRRING EQUIVALENCE IN THE PRESENCE OF A BOUNDARY
Authors: SHENG Z.-M. , GAO H.-B.
Published: October 2004

In this paper, the relationship between the sine-Gordon model with an integrable boundary condition and the Thirring model with boundary is discussed and the reflection R matrix for the massive Thirring model, which is related to the physical boundary parameters of the sine—Gordon model, is given. The relationship between the boundary parameters and the two formal parameters appearing in the work of Ghoshal and Zamolodchikov is also discussed.
CHARGE SCREENING IN THE FINITE TEMPERATURE SCHWINGER MODEL
Authors: GRIGNANI G. , SODANO P. , SEMENOFF G. , TIRKKONEN O.
Published: October 2004

We compute the effective action and correlators of the Polyakov loop operator in the Schwinger model at finite temperature and discuss the realization of the discrete symmetries that occur there. We show that, due to nonlocal effects of massless fermions in two space–time dimensions, the discrete symmetry which governs the screening of charges is spontaneously broken even in an effective one-dimensional model, when the volume is infinite. In this limit, the thermal state of the Schwinger model screens an arbitrary external charge; consequently the model is in the deconfined phase, with the charge of the deconfined fermions completely screened. In a finite volume we show that the Schwinger model is always confining.
ON MODULAR INVARIANT PARTITION FUNCTIONS OF CONFORMAL FIELD THEORIES WITH LOGARITHMIC OPERATORS
Authors: FLOHR MICHAEL A.I.
Published: October 2004

We extend the definitions of characters and partition functions to the case of conformal field theories which contain operators with logarithmic correlation functions. As an example we consider the theories with central charge c=cp,1=13−6(p+p−1), the “border” of the discrete minimal series. We show that there is a slightly generalized form of the property of rationality for such logarithmic theories. In particular, we obtain a classification of theories with c=cp,1 which is similar to the A-D-E classification of c=1 models.
THE CLASSICAL r MATRIX METHOD FOR THE NONLINEAR SIGMA MODEL
Authors: SEVOSTYANOV ALEXEY
Published: October 2004

The canonical Poisson structure of the nonlinear sigma model is presented as a Lie-Poisson r matrix bracket on coadjoint orbits. It is shown that the Poisson structure of this model is determined by some “hidden singularities” of the Lax matrix.
QUARK MASS HIERARCHY AND CP VIOLATION IN LOW ENERGY SUPERSYMMETRY
Authors: LIU CHUN
Published: October 2004

A pattern of quark mass hierarchy and CP violation within the framework of low energy supersymmetry is described. By assuming some discrete symmetry among the three families, the quarks of the third family obtain masses at tree level. The second family obtains masses radiatively at one-loop level due to the soft breaking of the family symmetry. At this level, the first family remains massless by some degeneracy conditions of the squarks. As a result of R parity violation, the sneutrino vacuum expectation values are nonvanishing. CP violation occurs through the superweak sneutrino exchange. This picture is consistent with the experiments on the flavor-changing neutral current.
SUPERSYMMETRIC QUANTUM COSMOLOGY SHAKEN, NOT STIRRED
Authors: MONIZ P.V.
Published: October 2004

The canonical quantization of N=1 and N=2 supergravity theories is reviewed in this report. Special emphasis is given to the topic of supersymmetric Bianchi class A and FRW minisuperspaces, namely in the presence of supermatter fields. The quantization of the general theory (including supermatter) is also contemplated. The issue of quantum physical states is subsequently analyzed. A discussion on further research problems still waiting to be addressed is included. An extensive and updated bibliography concludes this review.
RENORMALIZATION-GROUP STRUCTURE OF CONFORMAL QUANTUM GRAVITY WITH MATTER NEAR FOUR DIMENSIONS
Authors: ELIZALDE EMILIO , ODINTSOV SERGEI D. , ROMEO AUGUST
Published: October 2004

The phase structure and infrared (IR) properties of conformal quantum gravity (QG) with matter near four dimensions are studied using renormalization-group (RG) and ε- expansion techniques. For a variety of theories [like the O(N)φ4 theory, scalar electrodynamics and the SU(2) model with scalars] interacting with Weyl gravity, new fixed points for the scalar coupling may appear. The IR stable fixed point perturbed by QG results in a second-order phase transition at nonzero temperature. For the SU(2) gauge theory, which presumably describes the confining phase of the standard model, the RG-improved effective potential at nonzero temperature is found taking into account the QG contribution.
ON FORMULATIONS AND SOLUTIONS OF SIMPLEX EQUATIONS
Authors: CARTER J. SCOTT , SAITO MASAHICO
Published: October 2004

A version of the tetrahedral equation is formulated using a pictorial interpretation of the Frenkel-Moore equation. The picture gives a solution that is a product of quantum Yang-Baxter solutions. Higher-dimensional variants of the Frenkel-Moore equations are found from this pictorial interpretation, and the pictures reduce their solvability to the solvability of lower-dimensional equations.
BOUNDARY S MATRIX FOR THE TRICRITICAL ISING MODEL
Authors: CHIM LEUNG
Published: October 2004

The tricritical Ising model perturbed by the subleading energy operator [Formula: see text] was known to be an integrable scattering theory of massive kinks,14 and in fact it preserves supersymmetry. We consider here the model defined on the half-plane with a boundary and compute the associated factorizable boundary S matrix. The conformal boundary conditions of this model are identified and the corresponding S matrices are found. We also show how some of these S matrices can be perturbed and generate “flows” between different boundary conditions.
BICOVARIANT CALCULUS ON TWISTED ISO(N), QUANTUM POINCARÉ GROUP AND QUANTUM MINKOWSKI SPACE
Authors: ASCHIERI PAOLO , CASTELLANI LEONARDO
Published: October 2004

A bicovariant calculus on the twisted inhomogeneous multiparametric q groups of the Bn, Cn, Dn types, and on the corresponding quantum planes, is found by means of a projection from the bicovariant calculus on Bn+1, Cn+1, Dn+1. In particular we obtain the bicovariant calculus on a dilatation-free q Poincaré group ISO q(3, 1), and on the corresponding quantum Minkowski space.

The classical limit of the Bn, Cn, Dn bicovariant calculus is discussed in detail.
THE SCATTERING MATRIX APPROACH FOR THE QUANTUM BLACK HOLE: AN OVERVIEW
Authors: HOOFT G. 'T
Published: October 2004

If one assumes the validity of conventional quantum field theory in the vicinity of the horizon of a black hole, one does not find a quantum-mechanical description of the entire black hole that even remotely resembles that of conventional forms of matter; in contrast with matter made out of ordinary particles one finds that, even if embedded in a finite volume, a black hole would be predicted to have a strictly continuous spectrum.

Dissatisfied with such a result, which indeed hinges on assumptions concerning the horizon that may well be wrong, various investigators have now tried to formulate alternative approaches to the problem of “quantizing” the black hole. We here review the approach based on the assumption of quantum-mechanical purity and unitarity as a starting point, as has been advocated by the present author for some time, concentrating on the physics of the states that should live on a black hole horizon. The approach is shown to be powerful in producing not only promising models for the quantum black hole, but also new insights concerning the dynamics of physical degrees of freedom in ordinary flat space–time.
SOME MODIFIED RUNGE–KUTTA METHODS FOR THE NUMERICAL SOLUTION OF SOME SPECIFIC SCHRÖDINGER EQUATIONS AND RELATED PROBLEMS
Authors: SIMOS T. E. , WILLIAMS P. S.
Published: October 2004

Some new modified Runge–Kutta methods with minimal phase lag are developed for the numerical solution of the eigenvalue Schrödinger equation and related problems with oscillating solutions. These methods are based on the very well-known Runge–Kutta method of order 4. For the numerical solution of the eigenvalue Schrödinger equation, we investigate two cases: (i) the specific case in which the potential V(x) is an even function with respect to x; it is assumed, also, that the wave functions tend to zero for x → ±∞; (ii) the general case for the well-known cases of the Morse potential and Woods–Saxon or optical potential. Also, we have applied the new methods to some well-known problems with oscillatory solutions. Numerical and theoretical results show that this new approach is more efficient than the well-known classical fourth order Runge–Kutta method and the Numerov method.
GAUGE FIXING, CO-BRST AND TIME EVOLUTION IN QED
Authors: FÜLÖP GÉZA
Published: October 2004

We consider BRST-invariant inner product states for quantum electrodynamics constructed from trivial BRST-invariant states and a gauge regulator. The trivial states are products of matter and ghost states and are annihilated by Hermitian operators. The co-BRST operator and some further gauge-fixing regulators are found. The relation between gauge fixing and time evolution of both the trivial and the inner product states is discussed.
IMPLICATIONS OF "4 TEXTURE ZEROS" MASS MATRICES BASED ON G × SU(3)fam
Authors: GILL P. S. , GUPTA MANMOHAN
Published: October 2004

Texture specific mass matrices generated from the grand unified theory with global family symmetry, have been investigated in the context of latest data regarding [Formula: see text], |Vub|, |Vcb|, |Vtd|, |Vts| and other parameters depending on CKM matrix elements. Unlike several other phenomenological models, the present model not only accommodates the value of [Formula: see text] in the range 150–240 GeV, encompassing the CDF and D0 values, but is also able to reproduce |Vcb| = .038 ± .003 and |Vub/Vcb| = 0.08 ± 0.02, whereas |Vtd| is predicted in the range .005–.014. Further, the angles of the unitarity triangle, related to the CP-violating asymmetries, are in the ranges -1.0 ≤ sin 2α ≤ -.1, .6 ≤ sin 2α ≤ 1.0 and .48 ≤ sin 2β ≤ .56, in agreement with other recent calculations.
ON THE ALGEBRAIC RENORMALIZATION OF (1, 0)-SUPERSYMMETRIC GAUGED NONLINEAR σ MODELS
Authors: FRANCO DANIEL H. T.
Published: October 2004

We consider (1, 0)-supersymmetric nonlinear σ models coupled to Yang–Mills fields. By using a regularization-independent algebraic method, we discuss the renormalizability of these models. In particular, we show that, though the algebraic method signals a potential anomaly, fixed by means of a nontrivial cocycle, an inspection of the component-field action reveals that no anomaly can be generated.
$H^0\bar ff$ AND $Z\bar ff$ INTERACTIONS IN THEEFFECTIVE LAGRANGIAN APPROACH
Authors: HERNÁNDEZ J. M. , SAMPAYO O. A. , TOSCANO J. J.
Published: October 2004

We study possible effects induced by decoupled physics beyond the standard model on the decays [Formula: see text] and [Formula: see text] in the framework of effective Lagrangians. We consider only those dimension 6 [ SU L (2) × U Y (1)]-invariant fermionic operators that may be generated at tree level by the underlying physics. Using electroweak data, we get constraints on low energy new physics contributions to the partial widths [Formula: see text], including leptonic FCNC effects. We also discuss the underlying physics effects induced on [Formula: see text] of light fermions. In particular, we find a remarkable enhancement of the ēe, ūu and [Formula: see text] channels.
SECOND ORDER QCD CORRECTIONS TO THE NONLEPTONIC DECAY OF THE b QUARK IN THE SLOW CHARM LIMIT
Authors: VOLOSHIN M. B.
Published: October 2004

The perturbative QCD corrections to the nonleptonic decay rate of the b quark are discussed. By considering the limit where the final charmed quarks are slow, it is argued that the coefficients of the [Formula: see text] terms, corresponding to the next-to-next-to-leading order in the standard renormalization group expansion in ln (mW/mb), are naturally large. The large coefficients arise from the final state gluon exchange between quarks and are associated with the region of rather low momenta, which may further enhance the phenomenological significance of these terms.
HIGGS BOSON PRODUCTION UNDER THE RESONANCE THRESHOLD AT LEP II
Authors: BOOS E. , DUBININ M. , DUDKO L.
Published: October 2004

We consider the possibility of Higgs boson detection at LEP II under the resonance threshold [Formula: see text] in the framework of complete tree level approach to the calculation of the [Formula: see text] amplitude, simulating b quark fragmentation to hadrons and taking into account typical detector properties. At the energy below the 2mZ threshold [Formula: see text] Higgs boson production under the mH + mZ threshold is almost background free.
STATIC MAGNETOVAC SOLUTIONS
Authors: CHAUDHURI S. , DAS K. C.
Published: October 2004

The static magnetovac analog of the stationary gravitational solutions of Manko and Khakimov1 are presented, When the magnetic potential is switched off, the generated solution does not reduce to the Schwarzschild solution.
DUALITY OF MASSES AND LIFETIMES IN QUANTUM SYSTEMS
Authors: RAMANNA RAJA
Published: October 2004

In an earlier work it was shown that the masses (appropriately defined) and the lifetimes of radionuclides, and all the fundamental particles, could be obtained from a single integral parameter. In this paper it is shown that the theory based on Cantor's theory of cardinality is closely related to fractal dimension and is not only numerically consistent with the Fermi theory of β decay and the Gamow theory of a decay but also has wider applicability. The theory suggests a new way of looking at quantum mechanics based on discreteness and continuity. The work of Mitra et al. is used to show that the predictions of QCD on fundamental particles are consistent with the above theory with regard to discreteness.
NEUTRINO SELF-ENERGY AND DISPERSION EQUATION IN DENSE MATTER
Authors: MARTINEZ A. PEREZ , ZEPEDA A. , ROJAS H. PEREZ
Published: October 2004

General expressions for the neutrino self-energy and dispersion equations are found in a medium at finite temperature and density. The neutrino self-energy is calculated in the one-loop approximation and using the unitary gauge. The singularities and the absorption mechanisms are discussed. The low momentum (as compared with the vector boson masses) limit of the self-energy is obtained and from it, the dispersion equations for the quasiparticles are found. These solutions exhibit a group velocity smaller than unity which decreases with increasing density and an energy gap leading to a superfluid-type spectrum. In the particle–antiparticle asymmetric case, a negative effective mass is found for neutrinos.
STRONG SU(2) BREAKING AND MASS SPLITTINGS IN PSEUDOSCALAR MESONS
Authors: MITRA A. N.
Published: October 2004

The mass splittings within the SU(2) multiplets of pseudoscalar mesons (π, K, D, B) are used as a laboratory to determine the mass difference between d and u quarks (current), through the simplest (two-point) quark-loop diagrams for the self-energies of the corresponding hadrons, together with the associated quark-condensate diagrams within the loops. The second-order e.m. correction is also calculated with a photon line joining the two opposite quark lines in the self-energy loop. The basic ingredient is a hadron–quark-vertex function generated from a vector-exchange-like (chirally invariant) four-fermion Lagrangian (with current quarks) under dynamical symmetry breaking (DχSB), precalibrated to spectroscopy and other important low-energy amplitudes. The results which are expressed as proportional to the u−d mass difference δc, but are otherwise free from any adjustable parameters, reproduce in a rather accurate way all the SU(2) mass differences (from kaon to bottom) with δc = 4.0 MeV, when all the three self-energy diagrams are included. The pion receives only e.m. contributions with a value 5.24 MeV.
D-PARTICLE DYNAMICS AND BOUND STATES
Authors: DANIELSSON ULF H. , FERRETTI GABRIELE , SUNDBORG BO
Published: October 2004

We study the low energy effective theory describing the dynamics of D-particles. This corresponds to the quantum-mechanical system obtained by dimensional reduction of (9+1)-dimensional supersymmetric Yang-Mills theory to 0+1 dimensions and can be interpreted as the nonrelativistic limit of the Born-Infeld action. We study the system of two like-charged D-particles and find evidence for the existence of non-BPS states whose mass grows like λ1/3 over the BPS mass. We give a string interpretation of this phenomenon in terms of a linear potential generated by strings stretching from the two D-particles. Some comments on the possible relations to black hole entropy and elevendimensional supergravity are also given.
CLASSICAL SOLUTIONS IN FIVE-DIMENSIONAL-INDUCED MATTER THEORY AND ITS RELATION TO AN IMPERFECT FLUID
Authors: SOCORRO J. , VILLANUEVA V.M. , PIMENTEL LUIS O.
Published: October 2004

We study five-dimensional cosmological models with four-dimensional hypersurfaces of the Bianchi types I and V. In this way the five-dimensional vacuum field equations GAB=0 led us to four-dimensional matter equations Gμv=Tμv and the matter is interpreted as a purely geometrical property of a fifth dimension. Also, we find that the energy-momentum tensor induced from the fifth dimension has the structure of an imperfect fluid that has dissipative terms.
REIONIZATION OF THE UNIVERSE INDUCED BY PRIMORDIAL BLACK HOLES
Authors: GIBILISCO MARINA
Published: October 2004

The history of the universe after the recombination probably involves a reionization epoch, as the Gunn-Peterson test seems to suggest: if this is the case, the consequences of such a phenomenon should be relevant, both for the induced enhancement of the cosmic microwave background (CMB) polarization and for the possible damping of the CMB fluctuations on small angular scales (θ~1º).

In this paper, I will study a model of reionization at redshifts z≤60 caused by the evaporation of primordial black holes; photon emission only from nonrotating black holes is considered. A system of coupled differential equations, giving the time evolution of the ionization degree x, of the plasma temperature Te and of the photon number density nγ, is solved in an analytical way: the results obtained show that such a kind of reionization is possible, being able to increase the ionization degree of the universe from a value x=0.002 (just after the recombination) to values near 1 (when the black holes evaporation ends). In particular, taking the evaporation redshift equal to the reionization redshift zR, one obtains total reionization (i.e. x=1) for 15≤zR≤30, while only a partial effect (x~0.75÷0.90) is present for higher values of zR (40≤zR≤60). The fast increase of x seems to agree with the predictions of an exponential reionization model discussed in a previous study of the CMB polarization induced by gravitational waves.

The evolution of the plasma temperature Te is also estimated: it is affected in a less important way by the primordial black holes evaporation process, as we expect from the experimental FIRAS upper limit on the comptonization parameter yc (yc<2.5×10−5). The photoionization process here studied seems generally able to maintain the plasma in a ionized state without heating it up at very high temperatures; however, an improvement in the numerical calculation of Te is necessary in order to take into account in a more satisfactory way the collisional and excitation cooling, that can limit the increase of the plasma temperature.

In this model, the density of primordial black holes (PBH’s) necessary to give a nonnegligible reionization is an important parameter: here I will consider various birth times tin and various initial density for the PBH’s, showing that the most effective reionization is obtained for zR≤30 and for PBH’s formed at tin~10−28 secafter the big bang. An estimate of their present density for this formation time gives a value ρ0=2.44×10−38g cm−3, corresponding to a present density parameter ΩPBH equal to 5.20×10−9. This result agrees with the experimental upper limit ΩPBH≤(7.6±2.6)×10−9 h(−1.95±0.15)

A future improvement of this work will consider also massive particle emission from both rotating and nonrotating black holes and a spectrum taking also into account quarks and gluons jets emission.
QUANTUM EFFECTS OF STRINGY AND MEMBRANIC NATURE FOR THE SWIMMING OF MICRO-ORGANISMS IN A FLUID
Authors: ELIZALDE E. , KAWAMURA M. , SUGAMOTO A. , NOJIRI S. , ODINTSOV S.D.
Published: October 2004

The static potential is investigated in string and membrane theories coupled to U(1) gauge fields (specifically, external magnetic fields) and with antisymmetric tensor fields. The explicit dependence of the potential on the shape of the extended objects is obtained, including a careful calculation of the quantum effects. Noting the features which are common to the dynamics of strings and membranes moving in background fields and to the swimming of micro-organisms in a fluid. the latter problem is studied. The Casimir energy of a micro-organism is estimated, taking into account the quantum effects and the back reaction from the outside fluid.
CONVERGENT SEQUENCES OF PERTURBATIVE APPROXIMATIONS FOR THE ANHARMONIC OSCILLATOR I: HARMONIC APPROACH
Authors: BELLET B. , GARCIA P. , NEVEU A.
Published: October 2004

We present numerical evidence that a simple variational improvement of the ordinary perturbation theory of the quantum anharmonic oscillator can give a convergent sequence of approximations even in the extreme strong coupling limit, the purely anharmonic case. Some of the new techniques of this paper can be extended to renormalizable field theories.
CONVERGENT SEQUENCES OF PERTURBATIVE APPROXIMATIONS FOR THE ANHARMONIC OSCILLATOR II: COMPACT TIME APPROACH
Authors: BELLET B. , GARCIA P. , NEVEU A.
Published: October 2004

We present an alternative pathway in the application of the variation improvement of ordinary perturbation theory exposed in Ref. 1 which can preserve the internal symmetries of a model by means of a time compactification.
LITTLE MIRACLES OF SUPERSYMMETRIC EVOLUTION OF GAUGE COUPLINGS
Authors: SHIFMAN M.
Published: October 2004

The invention of supersymmetry, almost exactly 25 years ago,1 changed the face of high energy physics. The idea that the observed low energy gauge groups appear due to the process of spontaneous breaking of a single unifying group G is also quite popular. The synthesis of these two elements results in supersymmetric grand unification. I present (perturbatively) exact results regarding the supersymmetric evolution of the gauge couplings from the scale of their unification to lower scales. In particular, it is shown how the heavy mass thresholds can be properly taken into account to all orders.
INSIGHTS TO RESEARCH ON THE ENTREPRENEURIAL PROCESS FROM A STUDY ON PERCEPTIONS OF ENTREPRENEURSHIP AND ENTREPRENEURS
Authors: FAYOLLE ALAIN
Published: October 2004

The aim of this paper is to propose some perspectives in entrepreneurship research based on an analysis of existing knowledge and the results of a study recently conducted with a sample of experts and professionals in the field. The conclusions of the research as well as our contribution, underline the necessity to reconsider the object of study in order to increase knowledge in the field of entrepreneurship. It seems essential to us that more research should be focused on the entrepreneurial process and the very close combination of the entrepreneur and the entrepreneurial project.
BUSINESS ANGEL NETWORKS: A EUROPEAN PERSPECTIVE
Authors: AERNOUDT RUDY , ERIKSON TRULS
Published: October 2004

This paper highlights the importance of business angel networks, as a tool of stimulating an entrepreneurial culture and small business financing. It also sheds light on current practices and the dimensions of business angels in Europe. A study made in 1998 for the European Commission suggests that the potential for investments by business angels is estimated to be between 10 and 20 billion € [Euro] per year. This can be compared with the 3 million Euro in seed and startup investments made in 1999 by the venture capital industry. A remarkable difference, which deserves further attention.

This particular inquiry includes a brief benchmarking exercise on informal private investor networks, known as business angel networks. The background for this study is the underlying thesis that the potential for investments through business angels is insufficiently developed. Implications for policy makers and future research are discussed.
RISK TAKING IN INTRAPRENEURSHIP: TRANSLATING THE INDIVIDUAL LEVEL RISK AVERSION INTO THE ORGANIZATIONAL RISK TAKING
Authors: ANTONCIC BOSTJAN
Published: October 2004

Risk taking is important for entrepreneurship in existing organizations (intrapreneurship). This study contributes to intrapreneurship theory by explaining a paradoxical nature of translation of individual level risk aversion into organizational level risk taking behavior. A model for examination of this risk taking paradox in intrapreneurship is developed on the basis of intrapreneurship "theory," theory of planned behavior, prospect theory, agency theory and organizational culture perspective. A set of propositions is developed linking risk-related cognitions, behaviors and their antecedents. A model of risk taking in intrapreneurship is discussed here on the basis of propositions, and implications for research and practice.