January 1996 arXiv papers — page 6

Siqi Fu, Alexander V. Isaev, Steven G. Krantz

We give an example of a bounded, pseudoconvex, circular domain in ${\mathbb C}^3$ with smooth, real-analytic boundary and non-compact automorphism group, which is not biholomorphically equivalent to any Reinhardt domain.

Thomas Curtright, Tsuneo Uematsu, Cosmas Zachos

The Supersymmetric Dual Sigma Model (SDSM) is a local field theory introduced to be nonlocally equivalent to the Supersymmetric Chiral nonlinear sigma-Model (SCM), this dual equivalence being proven by explicit canonical transformation in tangent space. This model is here reconstructed in superspace and identified as a chiral-entwined supersymmetrization of

P. Claus

The combined method of Higher Covariant Derivatives and Pauli-Villars regularization to regularize pure Yang-Mills theories is formulated in the framework of Batalin and Vilkovisky. However, BRS invariance is broken by this method and suitable counterterms should be added to restore it. The one loop counterterm is presented. Contrary to the scheme of Slavnov

T. D. Bakeyev, A. A. Slavnov

The method of higher covariant derivative regularization of gauge theories is reviewed. The objections raised in the literature last years are discussed and the consistency of the method is proven. New approach to regularization of overlapping divergencies is developped.

J. Balog, P. Forgács, Z. Horváth, L. Palla

Various examples of target space duality transformations are investigated up to two loop order in perturbation theory. Our results show that when using the tree level (`naive') transformation rules the dual theories are in general {\it inequivalent} at two loops to the original ones, (both for the Abelian and the non Abelian duality).

A. Krajewska, A. Ushveridze, Z. Walczak

The paper is devoted to the further study of the remarkable classes of orthogonal polynomials recently discovered by Bender and Dunne. We show that these polynomials can be generated by solutions of arbitrary quasi - exactly solvable problems of quantum mechanichs both one-dimensional and multi-dimensional. A general and model-independent method for building

Duane A. Dicus, Wayne W. Repko

We investigate the production of a pseudoscalar Higgs-boson $A^0$ using the reaction $e\,γ\rightarrow e\,A^0$ at an $e\bar{e}$ collider with center of mass energy of 500 GeV. Supersymmetric contributions are included and provide a substantial enhancement to the cross section for most values of the symmetry breaking parameters. We find that, despite the penal

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

Jonathan L. Feng, Hitoshi Murayama, James D. Wells

At present, two outstanding discrepancies between experiment and the standard model are the measurements of the hadronic branching fractions $R_b$ and $R_c$. We note that an independent measurement of these branching fractions may be obtained from the width of hadronic $Z$ decays with a prompt photon, $Γ_{qqγ}$, along with the total hadronic decay rate, $Γ_{

T. Weigl, W. Melnitchouk

We present numerical solutions of the $Q^2$ evolution equations at next-to-leading order (NLO) for unpolarized and polarized parton distributions, in both the flavor non-singlet and singlet channels. The numerical method is based on a contour integration algorithm in complex-moment space, and, unlike most standard fitting techniques, is not restricted to the

Andrea Brignole, Ferruccio Feruglio, Fabio Zwirner

We examine the phenomenological implications of light $\tilde{t}_R$ and higgsinos in the Minimal Supersymmetric Standard Model, assuming $\tan^2 β< m_t / m_b$ and heavy $\tilde{t}_L$ and gauginos. In this simplified setting, we study the contributions to $Δm_{B_d}$, $ε_K$, $BR(b \rightarrow s γ)$, $R_b \equiv Γ(Z \rightarrow b \overline{b}) / Γ( Z \to {\rm h

B. Z. Kopeliovich, B. Povh, I. K. Potashnikova

Experiments at HERA looking for deep-inelastic electroproduction of neutrons in the proton fragmentation region are in progress. They are aimed to measure the pion structure function at small Bjorken $x$. The important condition for such a study is to establish under what kinematical conditions the dominance of the pion-pole graph in the process is guarantee

K. Melnikov, V. G. Serbo

It is known that some high-energy processes have a $t$-channel singularity in the physical region. In this paper we show that this singularity is regularized if one takes into account the finite sizes of the colliding beams, i.e. the realistic situation which takes place at high--energy colliders. On this way we obtain the finite cross section which is linea

Grigorios I. Poulis

Certain properties of maximal abelian projection are derived which suggest that the fundamental and adjoint SU(2) string tensions are reproduced by singly and doubly charged abelian Wilson loops, respectively. Thus, abelian dominance, which has been observed for color sources (quarks) in the fundamental representation, can be extended to higher representatio

T. Bhattacharya, R. Lacaze, A. Morel

We present a recursive method to calculate a large q expansion of the 2d q-states Potts model free energies based on the Fortuin-Kasteleyn representation of the model. With this procedure, we compute directly the ordered phase partition function up to order 10 in 1/sqrt{q}. The energy cumulants at the transition can be obtained with suitable resummation and

A. P. Heinson

In this paper I present the latest results on top quark physics from the DZero collaboration since the discovery of the top quark in March 1995. I summarize the discovery results, discuss progress since the discovery, and show how we can measure the top quark mass using three separate techniques. The measurements were made at the Fermilab Tevatron, a ppbar c

N. P. Landsman

This is an introduction to the author&#39;s recent work on constrained systems. Firstly, a generalization of the Marsden-Weinstein reduction procedure in symplectic geometry is presented - this is a reformulation of ideas of Mikami-Weinstein and Xu. Secondly, it is shown how this procedure is quantized by Rieffel induction, a technique in operator algebra th

Rafe Mazzeo, Daniel Pollack

In this paper we survey a number of recent results concerning the existence and moduli spaces of solutions of various geometric problems on noncompact manifolds. The three problems which we discuss in detail are: I. Complete properly immersed minimal surfaces in $\RR^3$ with finite total curvature. II. Complete embedded surfaces of constant mean curvature in

S. Curnoe, P. C. E. Stamp

We calculate the self-energy of fermions in Landau level n, in a finite field. Two cases are considered, in which fermions couple either to gauge fluctuations (as in the composite fermion gauge theory) or to phonons, as an example of a Fermi liquid. Perturbative calculations of the composite fermion spectrum show an unphysical suppression of the quasiparticl

F. Rojas, A. J. Bray

Using a cell dynamic system (CDS) simulation scheme, we investigate the phase-ordering dynamics of non-conserved O(n) models without topological defects, i.e. for $n > d+1$ where $d$ is the spatial dimensionality. In particular, we consider zero-temperature quenches for $d=2$, $n=4,5$, and for $d=1$, $n=3,4,5$. We find, in agreement with previous simulations

M. Buttiker, T. Christen

A theory of the dynamical conductance of mesoscopic conductors is presented. It is applied to mesoscopic capacitors, resonant double barriers, ballistic wires, metallic diffusive wires, and to the Corbino disk and the Hall bar in quantizing magnetic fields. Central to this approach is a discussion of the charge and potential distribution in mesoscopic conduc

T. Christen, M. Buttiker

We present a current and charge conserving theory for the low frequency admittance of a quantum point contact. We derive expressions for the electrochemical capacitance and the displacement current. The latter is determined by the {\em emittance} which equals the capacitance only in the limit of vanishing transmission. With the opening of channels the capaci

P. Prelovsek, J. Jaklic

Recent results for the finite-temperature static and dynamical properties of the planar $t-J$ model, obtained by a novel numerical method for small correlated systems, are reviewed. Of particular interest are $T>0$ charge and spin response functions: optical conductivity $σ(ω)$ and spin susceptibility $χ(\vec q,ω)$, which show very universal features at inte

Zbigniew Koza

We examine the long time behaviour of A+B->0 reaction diffusion systems with initially segregated species A and B. All of our analysis is carried out for arbitrary (positive) values of the diffusion constants $D_A$, $D_B$, and initial concentrations $a_0$ and $b_0$ of A&#39;s and B&#39;s. We divide the domain of the partial differential equations describing

T. H. Stoof, Yu. V. Nazarov

We present calculations of the temperature-dependent electrostatic and chemical potential distributions in disordered normal metal-superconductor structures. We show that they differ appreciably in the presence of a superconducting terminal and propose an experiment to measure these two different potential distributions. We also compute the resistance change

Franjo Franjic, Sandro Sorella

We present here a new approach to determine an accurate variational wavefunction for general quantum antiferromagnets, completely defined by the requirement to reproduce the simple and well known spin-wave expansion. By this wavefunction, it is possible to obtain the correct behavior of the long distance correlation functions for the one dimensional $S=1/2$

Michael P. Solf, Thomas A. Vilgis

We report on a novel approach to the Deam-Edwards model for interacting polymeric networks without using replicas. Our approach utilizes the fact that a network modelled from a single non-interacting Gaussian chain of macroscopic size can be solved exactly, even for randomly distributed crosslinking junctions. We derive an {\it exact} expression for the part

Richard Crouch, Robert Gaizauskas, Klaus Netter

This is an interim report discussing possible guidelines for the assessment and evaluation of projects developing speech and language systems. It was prepared at the request of the European Commission DG XIII by an ad hoc study group, and is now being made available in the form in which it was submitted to the Commission. However, the report is not an offici

Per Dahlqvist, Roberto Artuso

We compute the decay of the autocorrelation function of the observable $|v_x|$ in the Sinai billiard and of the observable $v_x$ in the associated Lorentz gas with an approximation due to Baladi, Eckmann and Ruelle. We consider the standard configuration where the disks is centered inside a unit square. The asymptotic decay is found to be $C(t) \sim c(R)/t$.

Luigi Guzzo

I review the present status of the mapping of the large-scale structure of the Universe through wide-angle redshift surveys. In the first part of the paper, I discuss the current state of the art, describing in some detail the recently completed ESO Slice Project (ESP). I then briefly recall some of the basic motivations for performing larger surveys. Then,

Edward W. Kolb, Antonio Riotto

In a class of low-energy supersymmetry models the photino is a natural dark matter candidate. We investigate the effects of post-freeze-out photino annihilations which can generate electromognetic cascades and lead to photo-destruction of $^4$He and subsequent overproduction of D and $^3$He. We also generalize our analysis to a generic dark matter component

Charles F. Gammie, Eve C. Ostriker

Using self-consistent magnetohydrodynamic (MHD) simulations, we explore the hypothesis that nonlinear MHD waves dominate the internal dynamics of galactic molecular clouds. We employ an isothermal equation of state and allow for self-gravity. We adopt ``slab-symmetry,&#39;&#39; which permits motions $\bf v_\perp$ and fields $\bf B_\perp$ perpendicular to the

T. D. Kinman, Jeffrey R. Pier, Nicholas B. Suntzeff, D. L. Harmer

The radial velocity dispersion of 67 RR Lyrae variable and blue horizontal branch (BHB) stars that are more than 4 kpc above the galactic plane at the North Galactic Pole is 110 km/sec and shows no trend with Z (the height above the galactic plane). Nine stars with Z < 4 kpc show a smaller velocity dispersion (40 +/-9 km/sec) as is to be expected if they mos

Alok R. Patnaik, Peter Schneider, Ramesh Narayan

The double QSO2345+007 comprises two optical components separated by 7.1\ arcseconds and is the most prominent `dark matter&#39; gravitational lens candidate. Despite being known for more than a decade, optical spectroscopy and imaging have been unable to determine whether this double QSO is a binary QSO or a gravitational lens system. In this note we report

Indranil Biswas

Let $M$ be a compact connected Kähler manifold and let ${\E}_{l-1}$ be the smallest term in the Harder-Narasimhan filtration of its tangent bundle. Let $G$ be an affine algebraic reductive group over $\C$. We prove the following result: If $M$ satisfies the condition that $°(T/{\E}_{l-1}) \geq 0$, then a holomorphic principal $G$-bundle $P$ on $M$ admitting

Oliver Küchle, Andreas Steffens

In the paper we present an alternative approach to the boundedness of Seshadri constants (which measure the local positivity) of nef and big line bundles at a general point of a complex--projective variety. Our approach is based on the construction of divisors in certain adjoint linear systems having isolated singularities of high order. A variant of the met

Shihoko Ishii

In this paper we give a criterion for an isolated, hypersurface singularity of dimension $n\ (\geq 2)$ to have the canonical modification by means of a suitable weighted blow-up. Then we give a counter example to the following conjecture by Reid-Watanabe: For a 3-dimensional, isolated, non-canonical, log-canonical singularity $(X,x)$ of embedded dimension 4,

Sergei Maslov

We derive an infinite hierarchy of exact equations for the Bak-Sneppen model in arbitrary dimensions. These equations relate different moments of temporal duration and spatial size of avalanches. We prove that the exponents of the BS model are the same above and below the critical point and express the universal amplitude ratio of the avalanche spatial size

L. Rozansky

R.~Lawrence has conjectured that for rational homology spheres, the series of Ohtsuki&#39;s invariants converges p-adicly to the SO(3) Witten-Reshetikhin-Turaev invariant. We prove this conjecture for Seifert rational homology spheres. We also derive it for manifolds constructed by a surgery on a knot in S^3. Our derivation is based on a conjecture about the

G. Modanese

The most recent data about the weak gravitational shielding produced recently through a levitating and rotating HTC superconducting disk show a very weak dependence of the shielding value ($\sim 1 \%$) on the height above the disk. We show that whilst this behaviour is incompatible with an intuitive vectorial picture of the shielding, it is consistently expl

P. Cea, L. Cosmai, A. D. Polosa

We propose a new method that by using the lattice Schr\"odinger functional allows to investigate the effective action for external background fields in lattice gauge theories. We show that this method gives sensible results for the case of four-dimensional U(1) gauge theory in an external constant magnetic field.

Peter Anninos, Joan Masso, Edward Seidel, Wai-Mo Suen

We report on a systematic study of the dynamics of gravitational waves in full 3D numerical relativity. We find that there exists an interesting regime in the parameter space of the wave configurations: a near-linear regime in which the amplitude of the wave is low enough that one expects the geometric deviation from flat spacetime to be negligible, but neve

M. Welling, M. Bijlsma

In this paper we derive an expression for the conserved Pauli-Lubanski scalar in &#39;t Hooft&#39;s polygon approach to 2+1-dimensional gravity coupled to point particles. We find that it is represented by an extra spatial shift $Δ$ in addition to the usual identification rule (being a rotation over the cut). For two particles this invariant is expressed in

Han-Wen Huang, Kuang-Ta Chao

Hadronic annihilation rate of $1^{+-}$ heavy quarkonium is given to next-to-leading order in $α_s$ and leading order in $v^2$ using a recently developed factorization formalism which is based on NRQCD. The result includes both the annihilation of P-wave color-singlet $Q\bar{Q}$ component, and the annihilation of S-wave color-octet $Q\bar{Q}$ component of the

Enrico Montanari, Pierluigi Fortini

The interaction of a gravitational wave with a system made of an RLC circuit forming one end of a mechanical harmonic oscillator is investigated. We show that, in some configurations, the coherent interaction of the wave with both the mechanical oscillator and the RLC circuit gives rise to a mechanical quality factor increase of the electromagnetic signal. W

Jerome P. Gauntlett, David A. Lowe

We analyze the spectrum of dyons in N=4 supersymmetric Yang-Mills theory with gauge group SU(3) spontaneously broken down to U(1)xU(1). The Higgs fields select a natural basis of simple roots. Acting with S-duality on the W-boson states corresponding to simple roots leads to an orbit of BPS dyon states that are magnetically charged with respect to one of the

Chryssomalis Chryssomalakos

We give a general integration prescription for finite dimensional braided Hopf algebras, deriving the N-dimensional quantum superplane integral as an example. The transformation properties of the integral on the quantum plane are found. We also discuss integration on quantum group modules that lack a Hopf structure.

J. A. Eden, M. F. Gari

The meson-nucleon dynamics that generates the hard core of the RuhrPot two-nucleon interaction is shown to vanish in the irreducible 3N force. This result indicates a small 3N force dominated by conventional light meson-exchange dynamics and holds for an arbitrary meson-theoretic Lagrangian. The resulting RuhrPot 3N force is defined in the appendix. A comple

S. A. Bass, A. Bischoff, J. A. Maruhn, H. Stoecker

An accurate impact parameter determination in a heavy ion collision is crucial for almost all further analysis. The capabilities of an artificial neural network are investigated to that respect. A novel input generation for the network is proposed, namely the transverse and longitudinal momentum distribution of all outgoing (or actually detectable) particles

Akira Iwamoto, Koji Niita, Toshiki Maruyama, Tomoyuki Maruyama

Intermediate mass fragment (IMF) multiplicity has been investigated for Au+Au reactions at incident energies of 100, 250 and 400 MeV/A. From the analysis of the impact-parameter-dependence of the IMF multiplicity using our QMD plus statistical evaporation model, we found that 1) statistical decay process modifies the results greatly, and 2) the Fermi motion

Sergei Alexandrov, Dmitri Vassilevich

The heat kernel expansion for a general non--minimal operator on the spaces $C^\infty (Λ^k)$ and $C^\infty (Λ^{p,q})$ is studied. The coefficients of the heat kernel asymptotics for this operator are expressed in terms of the Seeley coefficients for the Hodge--de Rham Laplacian.

H. Lu, C. N. Pope

We give a review of some recent work on the construction and classification of $p$-brane solutions in maximal supergravity theories in all dimensions $4\le D\le 11$. These solutions include isotropic elementary and solitonic $p$-branes, dyonic $p$-branes, and multi-scalar $p$-branes. These latter two categories include massless strings and black holes as spe

I. Bakas, K. Sfetsos

We examine the Toda frame formulation of the SO(3)-invariant hyper-Kahler 4-metrics, namely Eguchi-Hanson, Taub-NUT and Atiyah-Hitchin. Our method exploits the presence of a rotational SO(2) isometry, leading to the explicit construction of all three complex structures as a singlet plus a doublet. The Atiyah-Hitchin metric on the moduli space of BPS SU(2) mo

A. E. Dorokhov, S. V. Esaibegyan, N. I. Kochelev, N. G. Stefanis

Multi-instanton contributions to QCD sum rules for the pion are investigated within a framework which models the QCD vacuum as an instanton liquid. It is shown that in singular gauge the sum of planar diagrams in leading order of the $1/N_{c}$ expansion provides similar results as the effective single-instanton contribution. These effects are also analysed i

Matthias Burkardt

In the light-front form of field theory, boost invariance is a manifest symmetry. On the downside, parity and rotational invariance are not manifest, leaving the possibility that approximations or incorrect renormalization might lead to violations of these symmetries for physical observables. In this paper, it is discussed how one can turn this deficiency in

Glenn A. Ladinsky

One purpose of this meeting is to assess the physics potential of HERA-N Stage I. To develop a reasonable perspective, it is useful to look at other spin experiments. For completeness, this report discusses some of the single spin physics that has appeared in studies relating to the Relativistic Heavy Ion Collider (RHIC). (Talk presented during the meeting o

Glenn A. Ladinsky

A significant number of parameterizations for the polarized parton densities have appeared in the literature. Using the CTEQ evolution package, these distributions have been evolved consistently preparatory to compilation into an integrated package in the spirit of PDFLIB by Plothow-Besch. Here, a comparison of a few of the more recent distributions are made

Maria J. Herrero

The basic ingredients of the Spontaneous Symmetry Breaking Phenomenon and of the Higgs Mechanism are reviewed in these lectures of pedagogical character. Some relevant topics related with the breaking $\gs \rightarrow U(1)_{\rm em}$ are selected and discussed here. A brief survey of the experimental Higgs particle searches and the theoretical limits on $\mh$

B. Ananthanarayan, P. Büttiker

A Roy equation analysis of the available $ππ$ phase shift data is performed with the $I=0$ S- wave scattering length $a^0_0$ in the range predicted by the one-loop standard chiral perturbation theory. A suitable dispersive framework is developed to extract the chiral coupling constants \lb{1}, \lb{2} and yields \lb{1}$=-1.70\pm0.15$ and \lb{2}$\approx 5.0$.

B. Kileng, P. Osland, P. N. Pandita

At the Large Hadron Collider (LHC), the CP-even Higgs bosons ($h^0$ and $H^0$) of the Minimal Supersymmetric Standard Model (MSSM) will be searched for mainly through their two-photon decay. We present a detailed analysis of the production and two-photon decay of the CP-even Higgs bosons of MSSM at the LHC by taking into account all the parameters of the mod

Gerhard A. Schuler, Torbjörn Sjöstrand

We propose a generic ansatz for the extension of parton distributions of the real photon to those of the virtual photon. Alternatives and approximations are studied that allow closed-form parametrizations.

Shinya Kanemura, Takahiro Kubota, Hide-Aki Tohyama

The radiative corrections to the decays of the neutral CP-even Higgs boson $H$ into a longitudinal gauge boson pair, {\it i.e.}, $H \rightarrow Z_LZ_L$ and $W^+_LW^-_L$ are analyzed in the two Higgs doublet model by making use of the equivalence theorem. The sensitivity of the decay rates to the masses of the heavier Higgs bosons, charged $G^{\pm}$ and CP-od

M. Hasenbusch, S. Meyer, M. Pütz

We study the roughening transition of an interface in an Ising system on a 3D simple cubic lattice using a finite size scaling method. The particular method has recently been proposed and successfully tested for various solid on solid models. The basic idea is the matching of the renormalization-group-flow of the interface with that of the exactly solvable b

Jayashree Balakrishna, Gregory Daues, Edward Seidel, Wai-Mo Suen

We put forth a few ideas on coordinate conditions and their implementation in numerical relativity. Coordinate conditions are important for the long time scale simulations of relativistic systems, e.g., for the determination of gravitational waveforms from astrophysical events to be measured by LIGO/VIRGO. We demonstrate the importance of, and propose method

A. Taraphder, Rahul Pandit, H. R. Krishnamurthy, T. V. Ramakrishnan

We review the remarkable properties, including superconductivity, charge-density-wave ordering, and metal-insulator transitions, of lead- and potassium-doped barium bismuthate. We discuss some of the early theoretical studies of these systems. Our recent theoretical work, on the negative-$U\/$, extended-Hubbard model for these systems, is also described. Bot

L. Bertini

We consider the scaling limits for a one-dimensional random growth model, the weakly asymmetric single step Solid-on-Solid process. We show that the fluctuation field, if considered in an appropriate (long) space-time scale, solves the Kardar-Parisi-Zhang equation.

Yu. S. Barash, A. A. Svidzinsky

Dependences of low temperature behavior and anisotropy of various physical quantities for pure unconventional superconductors upon a particular form of momentum direction dependence for the superconducting order parameter (within the framework of the same symmetry type of superconducting pairing) are considered. A special attention is drawn to the possibilit

P. J. H. Denteneer

A strong-coupling expansion for the antiferromagnetic phase of the Hubbard model is derived in the framework of the slave-boson mean-field approximation. The expansion can be obtained in terms of moments of the density of states of freely hopping electrons on a lattice, which in turn are obtained for hypercubic lattices in arbitrary dimension. The expansion

Yutaka Okabe, Macoto Kikuchi

The idea of universal finite-size-scaling functions of the Ising model is tested by Monte Carlo simulations for various lattices. Not only regular lattices such as the square lattice but quasiperiodic lattices such as the Penrose lattice are treated. We show that the finite-size-scaling functions of the order parameter for various lattices are collapsed on a

J. E. F. Frost, C. -T. Liang, D. R. Mace, M. Y. Simmons

We report the results of two fundamental transport measurements at a Landau level filling factor $ν$ of 1/2. The well known ballistic electron transport phenomena of quenching of the Hall effect in a mesoscopic cross-junction and negative magnetoresistance of a constriction are observed close to B~=~0 and $ν~=~ 1/2$. The experimental results demonstrate semi

Y. M. Li, N. d&#39;Ambrumenil, L. Yu, Z. B. Su

The Green&#39;s function for a hole moving in an antiferromagnet is derived analytically in the long-wavelength limit. We find that the infrared divergence is eliminated in two and higher dimensions so that the quasiparticle weight is finite. Our results also suggest that the hole motion is polaronic in nature with a bandwidth proportional to $t/J \exp [-c (

Jarosław Piasecki, Pierre-Antoine Rey, Michel Droz

We study a simple one-dimensional model of ballisticaly-controlled annihilation in which the two annihilating species are initially spatially separated. The time dependent properties of the annihilation front are exactly derived. It is shown that the front wanders in a brownian fashion around its average value.

James Annett, Nigel Goldenfeld, Anthony Leggett

We present a critical discussion of recent experimental probes of the pairing state of the high temperature superconductors, focusing primarily, but not exclusively, on \Yba, where the best data currently exist. Penetration depth measurements near \Tc\ give no indication of an extra transition, indicating that the pairing state is a one-dimensional represent

Alexei Chekhlov, Steven A. Orszag, Semion Sukoriansky, Boris Galperin

The effect of small scale forcing on large scale structures in $β$-plane two-dimensional (2D) turbulence is studied using long-term direct numerical simulations (DNS). We find that nonlinear effects remain strong at all times and for all scales and establish an inverse energy cascade that extends to the largest scales available in the system. The large scale

Semion Sukoriansky, Alexei Chekhlov, Boris Galperin, Steven A. Orszag

Large eddy simulation (LES) of forced, homogeneous, isotropic, two-dimensional (2D) turbulence in the energy transfer subrange is the subject of this paper. A difficulty specific to this LES and its subgrid scale (SGS) representation is in that the energy source resides in high wave number modes excluded in simulations. Therefore, the SGS scheme in this case

T. Shigehara, Taksu Cheon

We study the low energy quantum spectra of two-dimensional rectangular billiards with a small but finite-size scatterer inside. We start by examining the spectral properties of billiards with a single pointlike scatterer. The problem is formulated in terms of self-adjoint extension theory of functional analysis. The condition for the appearance of so-called

M. Yu. Kuchiev

A theory for the many-electron multi-photon process is presented. It is shown that after single-electron excitation into some level in the continuum (ATI) an inelastic collision of the excited electron with the parent atomic particle can result in an excitation of the ion. It may be the continuum state excitation giving the doubly charged ion or the discrete

M. Yu. Kuchiev

ATI can be followed by an inelastic collision of the ionized electron with the parent atomic particle resulting in an excitation of the ion. It may be a continuum state excitation producing the doubly charged ion or a discrete state which also enhances the doubly charged ion production. Absorption of a few quanta above the atomic threshold is sufficient to m

Gerald D. Quinlan

The stellar ejection rate and the rates of change of the binary semimajor axis and eccentricity are derived from scattering experiments for the restricted three-body problem. They are used to study the evolution of binaries in simple models for galactic nuclei, starting soon after the black holes become bound and continuing until the evolution is dominated b

David Merritt

Hubble Space Telescope (HST) observations reveal that the density of stars in most elliptical galaxies rises toward the center in a power-law cusp. Many of these galaxies also contain central dark objects,possibly supermassive black holes. The gravitational force from a steep cusp or black hole will destroy most of the box orbits that constitute the ``backbo

Luis Gonzalez-Mestres

We discuss the possible cosmological implications of a class of superluminal particles, in a scenario where: a) Lorentz invariance is only an approximate property of the equations of a sector of matter; b) several critical speeds of matter in vacuum exist. The Big Bang scenario and the evolution of the very early universe, as well as large scale structure, c

Paolo Padovani, Paolo Giommi

We study the X-ray spectra of 85 BL Lacertae objects using the hardness ratios as given in the WGA catalogue of {\it ROSAT} sources. This sample includes all WGA BL Lacs with high-quality data and comprises about 50 per cent of presently known BL Lacs. We find that BL Lacs have energy power-law spectral indices between 0 and 3 with a mean value $α_{\rm x}\si

Tohru Nakashima, Yuichiro Takeda

We propose an algebro-geometric definition of the space of conformal blocks in the four dimensional Wess-Zumino-Witten theory introduced by Losev.et al..

Daniel Huybrechts

The known counterexamples to the global Torelli theorem for higher-dimensional hyperkahler manifolds are provided by birational manifolds. We address the question whether two birational hyperkahler manifolds (i.e. irreducible symplectic) manifolds always define non-separated points in the moduli space of marked manifolds. An affirmative answer is given for t

M. P. Nightingale, H. W. J. Blöte

We introduce a novel variance-reducing Monte Carlo algorithm for accurate determination of autocorrelation times. We apply this method to two-dimensional Ising systems with sizes up to $15 \times 15$, using single-spin flip dynamics, random site selection and transition probabilities according to the heat-bath method. From a finite-size scaling analysis of t

Benjamin P. Lee, Michael E. Fisher

Near-critical thermodynamics in the hard-sphere (1,1) electrolyte is well described, at a classical level, by Debye-Hueckel (DH) theory with (+,-) ion pairing and dipolar-pair-ionic-fluid coupling. But DH-based theories do not address density fluctuations. Here density correlations are obtained by functional differentiation of DH theory generalized to {\it n

Per Kraus, Frank Wilczek

We consider how two classes of heavy particles: extra vector-like families, and strongly interacting superpartners, manifest themselves below threshold, by interference of virtual loops with normal QCD processes. Quantitative estimates are presented.

Giovanni Jona-Lasinio, Carlo Presilla

By using numerical simulations, we investigate the dynamics of a quantum system of interacting bosons. We find an increase of properly defined mixing properties when the number of particles increases at constant density or the interaction strength drives the system away from integrability. A correspondence with the dynamical chaoticity of an associated $c$-n

M. M. Tung, J. Bernabeu, J. Penarrocha

We present a new derivation of the O(alpha_s) angular distribution of the outgoing $q$-quark in the production process $e^+ e^- \toγ,Z\to q\,\bar{q}(g)$. In our calculation, we express the three-particle phase-space integration of the gluon-bremsstrahlung process in terms of a general set of analytic integral solutions. A consistent treatment of the QCD one-

Shogo Tanimura

Target space duality is reconsidered from the viewpoint of quantization in a space with nontrivial topology. An algebra of operators for the toroidal bosonic string is defined and its representations are constructed. It is shown that there exist an infinite number of inequivalent quantizations, which are parametrized by two parameters $ 0 \le s, t < 1 $. The

Aharon Davidson, Uzi Paz

Imposing extendibility on Kasner-Fronsdal black hole local isometric embedding is equivalent to removing conic singularities in Kruskal representation. Allowing for globally non-trivial (living in $M_{5}\times S_{1}$) embeddings, parameterized by $k$, extendibility can be achieved for apparently forbidden frequencies $\omega_{1}(k)\le\omega (k)\le \omega_{2}

J&#34;urgen Fuchs, Bert Schellekens, Christoph Schweigert

A formula is presented for the modular transformation matrix S for any simple current extension of the chiral algebra of a conformal field theory. This provides in particular an algorithm for resolving arbitrary simple current fixed points, in such a way that the matrix S we obtain is unitary and symmetric and furnishes a modular group representation. The fo

C. M. Baugh, E. Gaztanaga

We compare the accuracy of published formulae that transform the linear perturbation theory power spectrum into the nonlinear regime against the results of an ensemble of large N-body simulations. We find that the modified transformation given by Jain, Mo and White (1995) performs well for initial fluctuations that have a power law power spectrum, but is les

Marek Czachor

Manifestly covariant formalism for Bargmann-Wigner fields is developed. It is shown that there exists some freedom in the choice of the form of the Bargmann-Wigner scalar product: The general product depends implicitly on a family of world-vectors. The standard choice of the product corresponds to timelike and equal vectors which define a ``time&#34; directi

Rudolf Haag

In the orthodox language of Quantum Mechanics the observer occupies a central position and the only &#34;real events&#34; are the measuring results. We argue here that this narrow view is not forced upon us by the lessons of Quantum Physics. An alternative language, closer to the intuitive picture of the working physicist in many areas, is not only possible

Piotr Garbaczewski, Robert Olkiewicz

In the paper with the above title, D. T. Gillespie [Phys. Rev. A 49, 1607, (1994)] claims that the theory of Markov stochastic processes cannot provide an adequate mathematical framework for quantum mechanics. In conjunction with the specific quantum dynamics considered there, we give a general analysis of the associated dichotomic jump processes. If we assu

Marek Czachor

Nonlinear generalization of the Dirac equation extending the standard paradigm of nonlinear Hamiltonians is discussed. ``Faster-than-light telegraphs&#34; are absent for all theories formulated within the new framework. A new metric for infinite dimensional Lie algebras associated with Lie-Poisson dynamics is introduced.

Z. Dziembowski, M. Fabre de la Ripelle, Gerald A. Miller

We study baryon spectroscopy including the effects of pseudoscalar meson exchange and one gluon exchange potentials between quarks, governed by $α_s$. The non-perturbative, hyperspherical method calculations show that one can obtain a good description of the data by using a quark-meson coupling constant that is compatible with the measured pion-nucleon coupl

Arnold W. Miller

This is a set of 288 questions written for a Moore-style course in Mathematical Logic. I have used these (or some variation) four times in a beginning graduate course. Topics covered are: propositional logic axioms of ZFC wellorderings and equivalents of AC ordinal and cardinal arithmetic first order logic, and the compactness theorem Lowenheim-Skolem theore

M. Alishahiha, A. H. Fatollahi, K. Kaviani

Chiral perturbation lagrangian in the framework of non-commutative geometry is considered in full detail. It is found that the explicit symmetry breaking terms appear and some relations between the coupling constants of the theory come out naturally. The WZW term also turns up on the same footing as the other terms of the chiral lagrangian.