arXiv papers from December 1995

Rajesh Gopakumar

As an illustration of the formalism of the master field we consider generalised $QCD_2$. We show how Wilson Loop averages for an arbitrary contour can be computed explicitly and with some ease. A generalised Hopf equation is shown to govern the behaviour of the eigenvalue density of Wilson loops. The collective field description of the theory is therefore de

B. Sathiapalan

The loop variable approach used earlier to obtain free equations of motion for the massive modes of the open string, is generalized to include interaction terms. These terms, which are polynomial, involve only modes of strictly lower mass. Considerations based on operator product expansions suggest that these equations are particular truncations of the full

Jan A. Kneissler

A special class of braids, called woven, is introduced and it is shown that every conjugation class of the braid group contains woven braids. In consequence, links can be presented as plats or closures of woven braids. Restricting on knots, we get the 'woven version' of the well-known theorem of Markov, giving moves that are capable of producing all woven br

Junheng Luo, Dominique Thiebaut

A noise-reduction algorithm for time-series of non-linear systems is presented. The algorithm smoothes the attractors in phase space using B-splines, allowing a more accurate measure of their dynamics. The algorithm is tested on numerical and experimental data. It is linear in complexity, and can be applied to embeddings of any dimension.

P. Bamert

We analyze LEP and SLC data from the 1995 Summer Conferences as well as from low energy neutral current experiments for signals of new physics. The reasons for doing this are twofold, first to explain the deviations from the standard model observed in $R_b$ and $R_c$ and second to constrain non-standard contributions to couplings of the $Z^0$ boson to all fe

S. J. Pollock, H. W. L. Naus, J. H. Koch

We examine commonly used approaches to deal with the scattering of electrons from a bound nucleon. Several prescriptions are shown to be related by gauge transformations. Nevertheless, due to current non-conservation, they yield different results. These differences reflect the size of the uncertainty that persists in the interpretation of $(e,e'p)$ experimen

Pierre van Baal

We review the specific problems that arise when studying instantons on a torus. We discuss how the Nahm transformation shows that no exact charge one instanton on T**4 can exist. However, taking one of the directions (the time) to infinity, it can be shown that vacuum to vacuum tunnelling solutions exist. A precise description of the moduli space for T**3xR,

A. R. Calderbank, Peter W. Shor

A quantum error-correcting code is defined to be a unitary mapping (encoding) of k qubits (2-state quantum systems) into a subspace of the quantum state space of n qubits such that if any t of the qubits undergo arbitrary decoherence, not necessarily independently, the resulting n qubits can be used to faithfully reconstruct the original quantum state of the

A. I. Posazhennikova, M. V. Sadovskii

It is demonstrated that the slope of the upper critical field $|dH_{c2}/dT|_{T_{c}}$ in superconductors with $d$-wave pairing drops rather fast with concentration of normal impurities, while in superconductors with anisotropic $s$-wave pairing $|dH_{c2}/dT|_{T_{c}}$ grows, and in the limit of strong disorder is described by the known dependences of the theor

Saul Barshay, Patrick Heiliger

If neutrinos have mass, we give reasons for a possible pattern of three (squared) mass eigenvalues: $m_1^2 \simeq (2.8 - 5.8) \, \mbox{(eV)}^2 $, $m_2^2 \simeq 0.01 \, \mbox{(eV)}^2 $, $m_3^2 \simeq (1.5 - 1) \times 10^{-4} \mbox{(eV)}^2 $. The flavor states $\nu_{\mu} $ and $\nu_e $ are mixtures of the eigen\-states with $m_2 $ and $m_3 $ with a significant

K. Kusakabe, H. Aoki

Inspired from Sutherland's work [Phys. Rev. Lett. {\bf 74}, 816 (1995)] on detecting bound spin waves, we propose that bound electron states can be detected from the dependence of interacting electron systems to the Aharonov-Bohm flux in the `extended zone' scheme, where the electron pairing halves the original period $N_a$ flux quanta in a system of linear

Ngee Pong Chang

The early big bang is an alphabet soup of quarks, W bosons, gluons, and other exotic particles and flavors. In the usual scenario, there is no place for the pion. It dissociates in the alphabet soup of the early universe. I will show that this scenario is naive. The thermal vacuum is a far more complex state, and the pion remains a Nambu-Goldstone particle a

Manuela Campanelli, Carlos O. Lousto

We find an {\it exact} pp--gravitational wave solution of the fourth order gravity field equations. Outside the (delta--like) source this {\it not} a vacuum solution of General Relativity. It represents the contribution of the massive, $m=(-\beta)^{-1/2}$, spin--two field associated to the Ricci squared term in the gravitational Lagrangian. The fourth order

J. Craig Wheeler

Observations of Type Ia supernovae (SN~Ia) combined with modeling of dynamics, light curves and spectra continue to point to the difficult conclusion that SN~Ia result from degenerate ignition in a carbon/oxygen white dwarf of the Chandrasekhar mass. Such a model accounts well for the ``normal" SN~Ia and for the observed dispersion exemplified by the lig

Alexander Gromov

Self-consistent mouvement of initial perturbation in density, velocity and gravitation potentail on the background of the stationary cylindrical configuration of the gas with gravitation and pressure in Lagrange variables have been studied. The nonlinear partial differential equation for description radius motion has been obtained. The linearization of this

Edward J. M. Colbert, S. A. Baum, J. F. Gallimore, C. P. O'Dea

We have launched a search for large-scale ($\gapprox$1 kpc) minor-axis outflows in edge-on Seyfert galaxies in order to assess their frequency of occurrence and study their properties. Here we present optical continuum and \han2 line images and/or minor-axis long-slit spectra of 22 edge-on Seyfert galaxies. Six of these galaxies show at least one of the foll

Ken Ganga, Bharat Ratra, Naoshi Sugiyama

Goodness-of-fit statistics are used to quantitatively establish the compatibility of CMB anisotropy predictions in a wide range of DMR-normalized, open and spatially-flat $\Lambda$, CDM cosmogonies with the set of all presently available small-scale CMB anisotropy detection data. Conclusions regarding model viability depend sensitively on the prescription us

Joseph L. Hora, William B. Latter

We present deep narrowband near-IR images and moderate resolution spectra of the young planetary nebula Hubble 12. These data are the first to show clearly the complex structure for this important planetary nebula. Images were obtained at lambda = 2.12, 2.16, and 2.26 micron. The lambda = 2.12 micron image reveals the bipolar nature of the nebula, as well as

A. Mariano, F. Krmpotic, A. F. R de Toledo Piza

It is shown that the norm corrections, introduced to avoid the violation of the constraints on the depletion of the hole states in the standard perturbative 2p2h approach, leads in nuclear matter to a dependence of the momentum distribution with the total nucleon number. This unphysical behavior, which in turn makes the depletion to be non-extensive, arises

Viacheslav V. Nikulin

We show that for any $N>0$ there exists a natural even $n>N$ such that the discriminant of moduli of K3 surfaces of the degree $n$ is not equal to the set of zeros of any automorphic form on the corresponding IV type domain. We give the necessary condition on a "condition $S\subset L_{K3}$ on Picard lattice of K3'' for the corresponding moduli $\M_{S\subset

Detlef Dürr, Sheldon Goldstein, Nino Zangh\`ı

We outline how Bohmian mechanics works: how it deals with various issues in the foundations of quantum mechanics and how it is related to the usual quantum formalism. We then turn to some objections to Bohmian mechanics, for example the fact that in Bohmian mechanics there is no back action of particle configurations upon wave functions. These lead us to our

A. Engel, M. Weigt

Random input patterns induce a partition of the coupling space of feed-forward neural networks into different cells according to the generated output sequence. For the perceptron this partition forms a random multifractal for which the spectrum $f(\alpha)$ can be calculated analytically using the replica trick. Phase transition in the multifractal spectrum c

T. D. Shoppa, M. Jeng, S. E. Koonin, K. Langanke

Recent laboratory experiments have measured fusion cross sections at center-of-mass energies low enough for the effects of atomic and molecular electrons to be important. To extract the cross section for bare nuclei from these data (as required for astrophysical applications), it is necessary to understand these screening effects. We study electron screening

Alan Kostelecky, Bogdan Tudose

Uncertainty relations between a bounded coordinate operator and a conjugate momentum operator frequently appear in quantum mechanics. We prove that physically reasonable minimum-uncertainty solutions to such relations have quantized expectation values of the conjugate momentum. This implies, for example, that the mean angular momentum is quantized for any mi

Alan Kostelecky, Malcolm Perry

A sequence of zero-temperature black-hole spacetimes with angular momentum and electric and magnetic charges is shown to exist in gauged $N=2$ supergravity. Stability of a subset of these spacetimes is demonstrated by saturation of the Bogomol'nyi bound arising from the supersymmetry algebra. The mass of the resulting solitonic black holes is given in terms

F. Delduc, M. Magro

We study the Poisson bracket algebra of the $N=2$ supersymmetric chiral WZNW model in superspace. It involves two classical r-matrices, one of which comes from the geometrical constraints implied by $N=2$ supersymmetry. The phase space itself consists of superfields satisfying constraints involving this r-matrix. An attempt is made to relax these constraints

F. Delduc, M. Magro

We give a gauge invariant formulation of $N=2$ supersymmetric abelian Toda field equations in \n2 superspace. Superconformal invariance is studied. The conserved currents are shown to be associated with Drinfeld-Sokolov type gauges. The extension to non-abelian \n2 Toda equations is discussed. Very similar methods are then applied to a matrix formulation in

Leo. V. Avdeev

Recurrence relations derived via the Chetyrkin--Tkachov method of integration by parts are applied to reduce scalar three-loop bubble (vacuum) diagrams with a mass to a limited number of master integrals. The reduction is implemented as a package of computer programs for analytic evaluation in FORM. The algorithms are applicable to diagrams with any integer

Edward Witten

We relate Type IIB superstrings compactified to six dimensions on K3 to an eleven-dimensional theory compactified on $({\bf S}^1)^5/{\bf Z}_2$. Eleven-dimensional five-branes enter the story in an interesting way.

Roger E. Behrend, Paul A. Pearce

We present a procedure in which known solutions to reflection equations for interaction-round-a-face lattice models are used to construct new solutions. The procedure is particularly well-suited to models which have a known fusion hierarchy and which are based on graphs containing a node of valency $1$. Among such models are the Andrews-Baxter-Forrester mode

B. L. Hu, Juan Pablo Paz, Yuhong Zhang

We address two basic issues in the theory of galaxy formation from fluctuations of quantum fields: 1) the nature and origin of noise and fluctuations and 2) the conditions for using a classical stochastic equation for their description. On the first issue, we derive the influence functional for a $\lambda \phi^4 $ field in a zero-temperature bath in de Sitte

Kazuo Takayanagi, Taksu Cheon

The charge longitudinal response function is examined in the framework of the random-phase approximation in an isospin-asymmetric nuclear matter where proton and neutron densities are different. This asymmetry changes the response through both the particle-hole interaction and the free particle-hole polarization propagator. We discuss these two effects on th

D. B. Fairlie, A. N. Leznov

A sequence of solutions to the equation of symmetry for the continuous Toda chain in $1+2$ dimensions is represented in explicit form. This fact leads to the supposition that this equation is completely integrable.

T. Shigehara, N. Yoshinaga, Taksu Cheon, T. Mizusaki

In this paper, we examine the level spacing distribution $P(S)$ of the rectangular billiard with a single point-like scatterer, which is known as pseudointegrable. It is shown that the observed $P(S)$ is a new type, which is quite different from the previous conclusion. Even in the strong coupling limit, the Poisson-like behavior rather than Wigner-like is s

Nils Andersson, Yasufumi Kojima, Kostas D. Kokkotas

An extensive survey of gravitational-wave modes for uniform density stars is presented. The study covers stars ranging in compactness from $R/M=100$ to the limit of stability in general relativity: $R/M = 9/4$. We establish that polar and axial gravitational-wave modes exist for all these stellar models. Moreover, there are two distinct families of both axia

V. Driesen, W. Hollik, J. Rosiek

We present the first complete 1-loop diagrammatic calculation of the cross sections for the neutral Higgs production processes $e^+e^-\ra Z^0h^0$ and $e^+e^-\ra A^0h^0$ in the minimal supersymmetric standard model. We compare the results from the diagrammatic calculation with the corresponding ones of the simpler and compact effective potential approximation

Dae Sung Hwang, Chang-Yeong Lee

We study the topological mass generation in the 4 dimensional nonabelian gauge theory, which is the extension of the Allen $et$ $al.$'s work in the abelian theory. It is crucial to introduce a one form auxiliary field in constructing the gauge invariant nonabelian action which contains both the one form vector gauge field $A$ and the two form antisymmetric t

Masao Matsumoto, Hiroshi Kuratsuji

We study characteristic aspects of the geometric phase which is associated with the generalized coherent states. This is determined by special orbits in the parameter space defining the coherent state, which is obtained as a solution of the variational equation governed by a simple model Hamiltonian called the "resonant Hamiltonian". Three typical coherent s

Naotaka Yoshinaga, Nobuaki Yoshida, Takaomi Shigehara, Taksu Cheon

The chaotic dynamics in nuclear collective motion is studied in the framework of a schematic shell model which has only monopole and quadrupole degrees of freedom. The model is shown to reproduce the experimentally observed global trend toward less chaotic motion in heavier nuclei. The relation between current approach and the earlier studies with bosonic mo

Hiroshi Kuratsuji, Hiroyuki Yabu

The Hamiltonian equation of motion is studied for a vortex occuring in 2-dimensional Heisenberg ferromagnet of anisotropic type by starting with the effective action for the spin field formulated by the Bloch (or spin) coherent state. The resultant equation shows the existence of a geometric force that is analogous to the so-called Magnus force in superfluid

T. Tochishita, M. Mizui, H. Kuratsuji

A new form of the Bohr-Sommerfeld quantization is given of the motion of guiding center in strong magnetic field. This is obtained by the effective action for the degree of guiding center which is deduced from the coherent state path integral for the two types of motion under the mutual interaction; the cyclotron motion and the motion of guiding center.

Paolo M. Gensini

The data from the last seven experiments performed on polarized deep--inelastic scattering on proton and neutron (or deuteron) targets have been analyzed in search of a precise determination of the spin fraction carried by the quarks in the nucleon. We find that this fraction can be of the size expected from na\"{\i}ve quark model arguments, provided the glu

Chang-Yeong Lee, Dae Sung Hwang, Yuval Ne'eman

The BRST quantization of a gauge theory in noncommutative geometry is carried out in the ``matrix derivative" approach. BRST/anti-BRST transformation rules are obtained by applying the horizontality condition, in the superconnection formalism. A BRST/anti-BRST invariant quantum action is then constructed, using an adaptation of the method devised by Baulieu

Esther M. Hu, Richard G. McMahon, Eiichi Egami

We report the detection of a nearby emission-line companion to the z=4.695 quasar BR1202-0725. Deep narrow-band exposures on this field from the UH 2.2 m show a Ly alpha flux of 1.5\times\ten{-16} ergs cm^{-2} s^{-1}. High-resolution HST WFC2 imaging in the F814W filter band shows continuum structure near the emission position, at 2.6" NW of the quasar, corr

Lisa Randall, Marin Soljacic, Alan Guth

Most models of inflation have small parameters, either to guarantee sufficient inflation or the correct magnitude of the density perturbations. In this paper we show that, in supersymmetric theories with weak scale supersymmetry breaking, one can construct viable inflationary models in which the requisite parameters appear naturally in the form of the ratio

Hiroyuki Hata, Hajime Oda, Shigeaki Yahikozawa

Quantization of free string field theory in the Rindler space-time is studied by using the covariant formulation and taking the center-of-mass value of the Rindler string time-coordinate $\eta(\sigma)$ as the time variable for quantization. We construct the string Rindler modes which vanish in either of the Rindler wedges $\pm$ defined by the Minkowski cente

Frank D. Smith,

The Rb and Rc crises described by Kaoru Hagiwara in hep-ph/9512425 can be resolved by the T-quark mass value of 130 GeV and the alpha_s(M_Z) value of 0.106 of the D4-D5-E6 model described in hep-ph/9501252 and quant-ph/9503009.

Sheldon Goldstein, Joel L. Lebowitz

This is the introduction to the section on Quantum Mechanics in the centennial collection of noteworthy articles appearing in The Physical Review and Physical Review Letters through 1983, since it all began in 1893. The selections for this section are "Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?" by Einstein, Podolsky and R

Keith A. Olive

The current status of big bang nucleosynthesis is reviewed. Particular attention is given to the degree at which the theory is consistent with the observation of the light element abundances.

A. O. Barvinsky, S. N. Solodukhin

A consistent variational procedure applied to the gravitational action requires according to Gibbons and Hawking a certain balance between the volume and boundary parts of the action. We consider the problem of preserving this balance in the quantum effective action for the matter non-minimally coupled to metric. It is shown that one has to add a special bou

A. Arhrib, J. -L. Kneur, G. Moultaka

We evaluate one-loop contributions to the C and P conserving $WW\gamma, WWZ$ form factors in the Minimal Supersymmetric Standard Model (MSSM), and in a more constrained Supergravity Grand Unified Theory (SUGRA-GUT). A systematic search of maximal effects in the available parameter space, shows that at LEP2 energy MSSM contributions can hardly reach the borde

A. Meszaros, P. Meszaros

We present analytic formulae for the integral number count distribution of cosmological bursting or steady sources valid over the entire range of fluxes, including density evolution and either standard candle or a power law luminosity function. These are used to derive analytic formulae for the mean redshift, the time dilations and the dispersion of these qu

Nobuyuki Sakai

According to previous work on magnetic monopoles, static regular solutions are nonexistent if the vacuum expectation value of the Higgs field $\eta$ is larger than a critical value $\eta_{{\rm cr}}$, which is of the order of the Planck mass. In order to understand the properties of monopoles for $\eta>\eta_{{\rm cr}}$, we investigate their dynamics numerical

Changhyun Ahn, E. Ivanov, S. Krivonos, A. Sorin

We discuss the N=2 extension of Polyakov-Bershadsky $W_3^{(2)}$ algebra with the generic central charge, $c$, at the quantum level in superspace. It contains, in addition to the spin 1 N=2 stress tensor, the spins $1/2, 2$ bosonic and spins $1/2, 2$ fermionic supercurrents satisfying the first class nonlinear chiral constraints. In the $c \to \infty $ limit,

Nobuyuki Sakai, Yoonbai Kim, Kei-ichi Maeda

We study the first-order phase transition in a model of scalar field with $O(3)$ symmetry coupled to gravity, and, in high temperature limit, discuss the existence of new bubble solution with a global monopole at the center of the bubble.

Mark Rakowski, Siddhartha Sen

We study abelian lattice gauge theory defined on a simplicial complex with arbitrary topology. The use of dual objects allows one to reformulate the theory in terms of new dynamical variables; however, we avoid the use of the dual lattice entirely. Topological modes which are present in the transformation now appear as homology classes, in contrast to the co

I. H. Hutchinson, B. LaBombard, B. Lipschultz

A set of experimentally-determined dimensionless parameters is proposed for characterizing the regime of divertor operation. The objective is to be able to compare as unambiguously as possible the operation of different divertors and to understand what physical similarities and differences they represent. Examples from Alcator C-Mod are given.

Nobuyuki Sakai

According to previous work on magnetic monopoles, static regular solutions are nonexistent if the vacuum expectation value of the Higgs field $\eta$ is larger than a critical value $\eta_{{\rm cr}}$, which is of the order of the Planck mass. In order to understand the properties of monopoles for $\eta>\eta_{{\rm cr}}$, we investigate their dynamics numerical

Y. Makeenko

I briefly review the present status of bosonic strings and discretized random surfaces in D>1 which seem to be in a polymer rather than stringy phase. As an explicit example of what happens, I consider the Kazakov-Migdal model with a logarithmic potential which is exactly solvable for any D (at large D for an arbitrary potential). I discuss also the meander

Rue-Ron Hsu, Bokai Yang, Chin-Rong Lee

We study the post-Newtonian limit of a generalized dilaton gravity in which gravity is coupled to dilaton and eletromagnetic fields. The field equations are derived using the post-Newtonian scheme, and the approximate solution is presented for a point mass with electric and dilaton charges. The result indicates that the dilaton effect can be detected, in pos

G. A. Drukier

Fokker-Planck models are used to give estimates for the retention fractions for newly-born neutron stars in globular clusters as a function of kick velocity. These can be used to calculate the present day numbers of neutron stars in globular clusters and in addressing questions such as the origin of millisecond pulsars. As an example, the Population I kick v

F. Belgiorno, M. Martellini

We review the problem of divergences in one--loop thermodynamical quantities for matter fields in thermal equilibrium on a black hole background. We discuss a number of results obtained for various thermodynamical quantities. Then we discuss the ansatz called ``literal interpretation" of zeroth law of black hole mechanics and try to explain the diseases of t

Ian I. Kogan, Nick E. Mavromatos

We discuss the target-space interpretation of the world-sheet logarithmic operators in string theory. These operators generate the normalizable zero modes (discrete states) in target space, which restore the symmetries of the theory broken by the background. The problem of the recoil in string theory is considered, as well as some general properties of strin

L. Okun

It is assumed that three lepton families $(\nu_e, e)$, $(\nu_{\mu}, \mu)$, $(\nu_{\tau}, \tau)$ carry charges, which are sources of electronic, muonic and tauonic massless vector particles, respectively. Various manifestations of these hypothetical photons are discussed.

Taksu Cheon

One-dimensional scattering by a target with two internal degrees of freedom is investigated. The damping of resonance peaks and the associated appearance of the fluctuating background in the quantum inelastic scattering amplitudes are found. Examination of the analog classical system reveals a disorderly reaction function, which is then related to the quantu

H. Aratyn, E. Nissimov, S. Pacheva

We illustrate the basic notions of {\em additional non-isospectral symmetries} and their interplay with the discrete {\em \DB transformations} of integrable systems at the instance of {\em constrained Kadomtsev-Petviashvili} (\cKP) integrable hierarchies. As a main application we present the solution of discrete multi-matrix string models in terms of Wronski

Rudolf Burkhalter

We define a fixed point action in two-dimensional lattice ${\rm CP}^{N-1}$ models. The fixed point action is a classical perfect lattice action, which is expected to show strongly reduced cutoff effects in numerical simulations. Furthermore, the action has scale-invariant instanton solutions, which enables us to define a correct topological charge without to

Taksu Cheon, Kazuo Takayanagi

The isospin-dependent component of the effective nucleon-nucleon interaction that causes the $\Delta T=1$ (p, p') and (p, n) reactions off nuclei is studied. It is shown that the corrections to the impulse approximation comes from the $g$-matrix type correction and the rearrangement term. They are numerically estimated with the isospin-asymmetric nuclear-mat

Takanori Sugihara, Masanobu Yahiro

A perturbative renormalization group (RG) scheme for light-front Hamiltonian is formulated on the basis of the Bloch-Horowitz effective Hamiltonian, and applied to the simplest $\phi^4$ model with spontaneous breaking of the $Z_2$ symmetry. RG equations are derived at one-loop order for both symmetric and broken phases. The equations are consistent with thos

Saurya Das, Parthasarathi Majumdar

Approximating light charged point-like particles in terms of (nonextremal) dilatonic black holes is shown to lead to certain pathologies in Planckian scattering in the eikonal approximation, which are traced to the presence of a (naked) curvature singularity in the metric of these black holes. The existence of such pathologies is confirmed by analyzing the p

Shoichi Midorikawa, Takayuki Kubo, Taksu Cheon

A system of coupled two logistic maps, one periodic and the other chaotic, is studied. It is found that with the variation of the coupling strength, the system displays several curious features such as the appearance of quadrupling of period, occurrence of isolated period three attractor and the coexistence of the Hopf and pitchfork bifurcations. Possible ap

J. Katriel, C. Quesne

A recursive deformation of the boson commutation relation is introduced. Each step consists of a minimal deformation of a commutator $[a,\ad]=f_k(\cdots;\no)$ into $[a,\ad]_{q_{k+1}}=f_k(\cdots;\no)$, where $\cdots$ stands for the set of deformation parameters that $f_k$ depends on, followed by a transformation into the commutator $[a,\ad]=f_{k+1}(\cdots,\,

Jisuke Kubo, Myriam Mondragon, Marek Olechowski, George Zoupanos

Gauge-Yukawa Unification (GYU) relates the gauge and Yukawa couplings, thereby going beyond the usual GUTs, and it is assumed that the GYU in the third fermion generation implies that its Yukawa couplings are of the same order as the unified gauge coupling at the GUT scale. We re-examine carefully the recent observation that the top-bottom mass hierarchy can

K. Ishikawa, T. Inagaki, T. Muta

We investigate four-fermion interactions with $N$-component fermion in Einstein universe for arbitrary space-time dimensions ($2 \leq D<4$). It is found that the effective potential for composite operator $\overline{\psi}\psi$ is calculable in the leading order of the $1/N$ expansion. The resulting effective potential is analyzed by varying the curvature of

Yoshiaki Sofue

We point out a possible association of high-velocity molecular gas with the Galactic Center Radio Lobe (GCL). A molecular spur in the eastern GCL ridge is receding at $\Vlsr \sim +100$ \kms, and the western spur approaching at $\Vlsr \sim -150$ \kms, suggesting a high-velocity rotation of the GCL. We study the kinematics of the GCL based on these molecular l

T. Inagaki, K. Ishikawa, T. Muta

Two-point functions for scalar and spinor fields are investigated in Einstein universe ($R \otimes S^{\sN-1}$). Equations for massive scalar and spinor two-point functions are solved and the explicit expressions for the two-point functions are given. The simpler expressions for massless cases are obtained both for the scalar and spinor cases.

Y. Iwasaki, K. Kanaya, T. Yoshié, T. Hoshino

We present results of a high statistics calculation of hadron masses and meson decay constants in the quenched approximation to lattice QCD with Wilson quarks at $\beta=$ 5.85 and 6.0 on $24^3 \times 54$ lattices. We analyze the data paying attention in particular to the systematic errors due to the choice of fitting range and due to the contamination from e

T. D. Cohen, J. L. Friar, G. A. Miller, U. van Kolck

We use power-counting arguments as an organizing principle to apply chiral perturbation theory, including an explicit $\Delta$, to the $p p \rightarrow p p \pi^0$ reaction near threshold. There are two lowest-order leading mechanisms expected to contribute to the amplitude with similar magnitudes: an impulse term, and a $\Delta$-excitation mechanism. We exam

Ashoke Sen

We investigate possible existence of duality symmetries which exchange the Kaluza-Klein modes with the wrapping modes of a BPS saturated $p$-brane on a torus. Assuming the validity of the conjectured $U$-duality symmetries of type II and heterotic string theories and $M$-theory, we show that for a BPS saturated $p$-brane there is an SL(2,Z) symmetry that mix

Ken Sasaki

It is proposed to use the pinch technique (PT) to obtain the gauge-independent thermal $\beta$ function $\beta_T$ in a hot Yang-Mills gas. Calculations of the thermal $\beta$ function are performed at one-loop level in four different gauges, (i) the background field method with an arbitrary gauge parameter, (ii) the Feynman gauge, (iii) the Coulomb gauge, an

A. P. Bakulev, S. V. Mikhailov

In a recent paper [1] we have proposed a new approach for extracting the wave function of the $\pi$-meson $\varphi_{\pi}(x)$ and the masses and wave functions of its first resonances from the new QCD sum rules for non-diagonal correlators obtained in [2]. Here, we test our approach using an exactly solvable toy model as an illustrating example. We demonstrat

Dileep P. Jatkar, Avinash Khare

We show that a Calogero-Sutherland type model with anharmonic interactions of fourth and sixth orders leads to the matrix model corresponding to the branched polymers. We also show that by suitably modifying this model one can also obtain N-particle problems which are connected to matrix models corresponding to the pure gravity phase as well as corresponding

R. Akhoury, V. I. Zakharov

We consider power-like corrections in QCD which can be viewed as power surpressed infrared singularities. We argue that the presence of these singularities depends crucially on the energy resolution. In case of poor energy resolution, i.e., inclusive cross sections, there are constraints on infrared singularities expressed by the Kinoshita-Lee-Nauenberg (KLN

M. Kreuzer, H. Skarke

Reflexive polyhedra encode the combinatorial data for mirror pairs of Calabi-Yau hypersurfaces in toric varieties. We investigate the geometrical structures of circumscribed polytopes with a minimal number of facets and of inscribed polytopes with a minimal number of vertices. These objects, which constrain reflexive pairs of polyhedra from the interior and

Roumen Borissov, Seth Major, Lee Smolin

The discrete picture of geometry arising from the loop representation of quantum gravity can be extended by a quantum deformation. The operators for area and volume defined in the q-deformation of the theory are partly diagonalized. The eigenstates are expressed in terms of q-deformed spin networks. The q-deformation breaks some of the degeneracy of the volu

Daniel A. Hamburger, A. Tamar Yinnon, Itshak Farbman, Avinoam Ben-Shaul

The angular intensity distribution of He beams scattered from compact clusters and from diffusion limited aggregates, epitaxially grown on metal surfaces, is investigated theoretically. The purpose is twofold: to distinguish compact cluster structures from diffusion limited aggregates, and to find observable {\em signatures} that can characterize the compact

Alain Lascoux, Bernard Leclerc, Jean-Yves Thibon

We introduce a new family of symmetric functions, which are $q$-analogues of products of Schur functions defined in terms of ribbon tableaux. These functions can be interpreted in terms of the Fock space representation of the quantum affine algebra of type $A_{n-1}^{(1)}$ and are related to Hall-Littlewood functions via the geometry of flag varieties. We pre

Abhijit K. Kshirsagar, S. V. Ghaisas

Using the dynamic renormalization group (DRG) technique, we analyze general nonlinearities in a conservative nonlinear growth equation with non-conserved gaussian white noise. We show that they fall in two classes only: the Edwards-Wilkinson and Lai-Das Sarma types, by explicitly computing the associated amputated two and three point functions at the first o

G. Falkovich, I. Kolokolov, V. Lebedev, A. Migdal

We propose the new method for finding the non-Gaussian tails of probability distribution function (PDF) for solutions of a stochastic differential equation, such as convection equation for a passive scalar, random driven Navier-Stokes equation etc. Existence of such tails is generally regarded as a manifestation of intermittency phenomenon. Our formalism is

Haye Hinrichsen

We show in the example of a one-dimensional asymmetric exclusion process that stationary states of models with parallel dynamics may be written in a matrix product form. The corresponding algebra is quadratic and involves three different matrices. Using this formalism we prove previous conjectures for the equal-time correlation functions of the model.

Mitsuhiro Kato

Several examples of similarity transformations connecting two string theories with different backgrounds are reviewed. We also discuss general structure behind the similarity transformations from the point of view of the topological conformal algebra and of the non-linear realization of gauge symmetry.

Tomohiro Inagaki

Curvature induced phase transition is thoroughly investigated in a four- fermion theory with $N$ components of fermions for arbitrary space-time dimensions $(2 \leq D < 4)$. We adopt the $1/N$ expansion method and calculate the effective potential for a composite operator $\bar{\psi}\psi$. The resulting effective potential is expanded asymptotically in terms

Victor Ginzburg, Mikhail Kapranov, Eric Vasserot

Hecke algebras are usually defined algebraically, via generators and relations. We give a new algebro-geometric construction of affine and double-affine Hecke algebras (the former is known as the Iwahori-Hecke algebra, and the latter was introduced by Cherednik [Ch1]). More generally, to any generalized Cartan matrix A and a point q in a 1-dimensional comple

Orfeu Bertolami, Juan García-Bellido

We investigate the astrophysical and cosmological implications of the recently proposed idea of a running gravitational coupling on macroscopic scales. We find that when applied to the rotation curves of galaxies, their flatness requires still the presence of dark matter. Bounds on the variation of the gravitational coupling from primordial nucleosynthesis,

A. A. Maslikov, I. A. Naumov, G. G. Volkov

In the framework of the four dimensional heterotic superstring with free fermions we present a revised version of the rank eight Grand Unified String Theories (GUST) which contain the $SU(3)_H$-gauge family symmetry. We also develop some methods for building of corresponding string models. We explicitly construct GUST with gauge symmetry $ G = SU(5) \times U

Robert Shrock

We discuss some implications of anomaly cancellation in the standard model with (i) the color group extended to $SU(N_c)$, and (ii) the leptonic sector extended to allow right-handed components for neutrinos.

Sheldon Goldstein

This is a review-essay on ``Speakable and Unspeakable in Quantum Mechanics'' by John Bell and ``The Undivided Universe: An Ontological Interpretation of Quantum Mechanics'' by David Bohm and Basil Hiley. The views of these authors concerning the character of quantum theory and quantum reality---and, in particular, their approaches to the issues of nonlocalit

Juan Carlos D'Olivo, Jose F. Nieves

Neutrinos propagating in matter acquire an effective electromagnetic vertex induced by their weak interactions with the charged particles in the background. In the presence of an external magnetic field the induced vertex affects the flavor transformations of mixed neutrinos in a way that, in contrast to the oscillations driven by an intrinsic magnetic momen

A. A. Andrianov, N. V. Romanenko

The fine-tuning principles are examined to predict the top-quark and Higgs-boson masses. The modification of the Veltman condition based on the compensation of vacuum energies is developed. It is implemented in the Standard Model and in its minimal extension with two Higgs doublets and Left-Right symmetric Model. The top-quark and Higgs-boson couplings are f

A. Bialas, R. Peschanski

Using the QCD dipole picture of the BFKL pomeron, the gluon contribution to the cross-section for single diffractive dissociation in deep-inelastic high-energy scattering is calculated. The resulting contribution to the proton diffractive structure function integrated over $t$ is given in terms of relevant variables, $x_{\cal P}, Q^2, $ and $\beta = x_{Bj}/x