March 1999 arXiv papers — page 20

G. Z. Obrant, M. G. Ryskin

Multipion production in high energy nucleus-nucleus collisions is considered in the model of the pion radiation by classical current. Strong coherent effects of narrowing of pion longitudinal and transverse momenta distributions are predicted at the RHIC energy. The coherence enhances the large pseudorapidities producing the bump in the distribution. The gro

F. Brau

In this paper, we construct an analytical solution of the one-dimensional spinless Salpeter equation with a Coulomb potential supplemented by a hard core interaction, which keeps the particle in the x positive region.

Jyh-Liong Lim, Hsiang-nan Li

We demonstrate that all the known single- and double-logarithm summations for a parton distribution function can be unified in the Collins-Soper resummation technique by applying soft approximations appropriate in different kinematic regions to real gluon emissions. Neglecting the gluon longitudinal momentum, we obtain the $k_T$ (double-logarithm) resummatio

Andreas Freund

In the first chapter we give an introduction to hard diffractive scattering in QCD to introduce basic concepts and terminology. In the second chapter we make predictions for the evolution of skewed parton distributions in a proton in the LLA. We calculate the DGLAP-type evolution kernels in the LLA and solve the skewed GLAP evolution equations with a modifie

J. Bartels, H. Jung, M. Wüsthoff

We study the diffractive production of $q\bar{q}g$ jets with large transverse momenta in the region of large diffractive masses (small $β$). Cross sections for transverse and longitudinal photons are obtained in the leading log $1/x_{\fP}$ and log $1/β$ approximation, keeping all powers in log $k_t^2/Q^2$. We perform a numerical study and illustrate the angu

Massimo Giovannini

The energy spectra of gravitational waves (GW) produced in quintessential inflationary models increase in frequency and exhibit a sharp spike around 170 GHz where the associated fraction of critical energy density today stored in relic gravitons is of the order of $10^{-6}$. We contrast our findings with the spectra of ordinary inflationary models and we com

Ulrich Heinz

The present status of the heavy-ion program to search for quark-gluon plasma is reviewed. The goal of this program is to recreate the Big Bang in the laboratory, by generating small chunks of exploding quark-gluon plasma (``The Little Bang''). I argue that the analogues of the three pillars of Big Bang Theory (Hubble flow, microwave background radiat

Fabrizio Gabbiani

Rare kaon decays are an important testing ground of the electroweak flavor theory: They can provide new signals of CP-violating phenomena. The interplay of long-distance QCD effects in strangeness-changing transitions can be analyzed with Chiral Perturbation Theory techniques. In particular, two rare kaon decays are analyzed: The first decay, K_L -> pi0 e+e-

M. Caselle, M. Hasenbusch, P. Provero

We show that the spectrum of the three dimensional phi^4 theory in the broken symmetry phase contains non-perturbative states. We determine the spectrum using a new variational technique based on the introduction of operators corresponding to different length scales. The presence of non-perturbative states accounts for the discrepancy between Monte Carlo and

CPLEAR Collaboration, J. Ellis, N. E. Mavromatos, D. V. Nanopoulos

We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time, we search for possible annual, monthly and diurnal modulations of the observables |eta_{+-}| and phi_{+-}, that could be correlated with variations in astrophysical potentials. Within the accuracy of CPLEAR

Marco Godina, Paolo Matteucci, Lorenzo Fatibene, Mauro Francaviglia

Two-spinor formalism for Einstein Lagrangian is developed. The gravitational field is regarded as a composite object derived from soldering forms. Our formalism is geometrically and globally well-defined and may be used in virtually any 4m-dimensional manifold with arbitrary signature as well as without any stringent topological requirement on space-time, su

J. Bicak, A. Pravdova

By using the Bondi-Sachs-van der Burg formalism we analyze the asymptotic properties at null infinity of axisymmetric electrovacuum spacetimes with a translational Killing vector and, in general, an infinite ``cosmic string'' (represented by a conical singularity) along the axis. Such spacetimes admit only a local null infinity. There is a non-vanish

H. R. Beyer, K. D. Kokkotas

We present a mathematically rigorous proof that the r-mode spectrum of relativistic stars to the rotational lowest order has a continuous part. A rigorous definition of this spectrum is given in terms of the spectrum of a continuous linear operator. This study verifies earlier results by Kojima (1998) about the nature of the r-mode spectrum.

Reinoud J. Slagter

We investigated the stability of the spherically symmetric non-abelian (Bartnik-McKinnon) black hole solution of the SU(2) Einstein-Yang-Mills system using the multiple-scale analysis. It is found, in contrast with the vacuum situation, that a spherically symmetric oscillatory perturbation to second order cannot be constructed. The singular behavior of gravi

Diane J. Litman, Shimei Pan

Recent technological advances have made it possible to build real-time, interactive spoken dialogue systems for a wide variety of applications. However, when users do not respect the limitations of such systems, performance typically degrades. Although users differ with respect to their knowledge of system limitations, and although different dialogue strateg

Marc Dymetman

This paper, following (Dymetman:1998), presents an approach to grammar description and processing based on the geometry of cancellation diagrams, a concept which plays a central role in combinatorial group theory (Lyndon-Schuppe:1977). The focus here is on the geometric intuitions and on relating group-theoretical diagrams to the traditional charts associate

Anatoly D. Plotnikov

For arbitrary undirected graph $G$, we are designing SATISFIABILITY problem (SAT) for HCP, using tools of Boolean algebra only. The obtained SAT be the logic formulation of conditions for Hamiltonian cycle existence, and use $m$ Boolean variables, where $m$ is the number of graph edges. This Boolean expression is true if and only if an initial graph is Hamil

Eric A. Cornell, Jason R. Ensher, Carl E. Wieman

Both theoretical and experimental activity in BEC has expanded dramatically in the three years since the first observation of BEC in a dilute atomic gas. One is tempted to ask, why? Why is there so much interest in the field? Is this burst of activity something that could have been foreseen, in, say, 1990?

Marc Barthelemy, Luis A. N. Amaral

Watts and Strogatz [Nature 393, 440 (1998)] have recently introduced a model for disordered networks and reported that, even for very small values of the disorder $p$ in the links, the network behaves as a small-world. Here, we test the hypothesis that the appearance of small-world behavior is not a phase-transition but a crossover phenomenon which depends b

A. K. Rajagopal, Constantino Tsallis

The Lie-Trotter formula $e^{\hat{A}+\hat{B}} = \lim_{N\to \infty} (e^{\hat{A}/N} e^{\hat{B}/N})^N$ is of great utility in a variety of quantum problems ranging from the theory of path integrals and Monte Carlo methods in theoretical chemistry, to many-body and thermostatistical calculations. We generalize it for the q-exponential function $e_q (x) = [1+ (1-q

X. S. Chen, V. Dohm

We reexamine the range of validity of finite-size scaling in the $ϕ^4$ lattice model and the $ϕ^4$ field theory below four dimensions. We show that general renormalization-group arguments based on the renormalizability of the $ϕ^4$ theory do not rule out the possibility of a violation of finite-size scaling due to a finite lattice constant and a finite cutof

X. S. Chen, V. Dohm

We study cutoff and lattice effects in the O(n) symmetric $ϕ^4$ theory for a $d$-dimensional cubic geometry of size $L$ with periodic boundary conditions. In the large-N limit above $T_c$, we show that $ϕ^4$ field theory at finite cutoff $Λ$ predicts the nonuniversal deviation $\sim (ΛL)^{-2}$ from asymptotic bulk critical behavior that violates finite-size

C. Bourbonnais, D. Jerome

We review the properties of quasi-one-dimensional organic superconductors: the Bechgaard salts and their sulfur analogs in their normal phase precursor tolong-range order. We go through the main observations made in the normal state of these systems at low magnetic field and tackle the issue of their description under the angles of the Fermi and Luttinger li

M. A. Martin-Delgado, G. Sierra, R. M. Noack

A simplified version of White's Density Matrix Renormalization Group (DMRG) algorithm has been used to find the ground state of the free particle on a tight-binding lattice. We generalize this algorithm to treat the tight-binding particle in an arbitrary potential and to find excited states. We thereby solve a discretized version of the single-particle S

I. Campillo, A. Rubio, J. M. Pitarke

The role of localized $d$-bands in the dynamical response of Cu is investigated, on the basis of {\em ab initio} pseudopotential calculations. The density-response function is evaluated in both the random-phase approximation (RPA) and a time-dependent local-density functional approximation (TDLDA). Our results indicate that in addition to providing a polariz

F. Onufrieva, P. Pfeuty

We have discovered a new example of quantum spin liquid which is a superconducting (SC) phase in 2D electron system close to electronic topological transition. As a quantum spin liquid in low dimensional localized spin systems it is characterized by a resonance spin mode and a well separated two-particle continuum. Application of the theory to the high-T_c c

L. A. Braunstein, R. C. Buceta, A. Diaz-Sanchez

We present the microscopic equation of growing interface with quenched noise for the Tang and Leschhorn model [{\em Phys. Rev.} {\bf A 45}, R8309 (1992)]. The evolution equations for the mean heigth and the roughness are reached in a simple way. Also, an equation for the interface activity density (i.e. interface density of free sites) as function of time is

L. A. Braunstein, R. C. Buceta, A. Diaz-Sanchez

We present the microscopic equation of growing interface with quenched noise for the Tang and Leschhorn model [L. H. Tang and H. Leschhorn, Phys. Rev. A {\bf 45}, R8309 (1992)]. The evolution equation for the height, the mean height, and the roughness are reached in a simple way. An equation for the interface activity density (or free sites density) as funct

Mireille Lavagna, Catherine Pepin

In this lecture, we review the experimental situation of heavy Fermions with emphasis on the existence of a quantum phase transition (QPT) and related non-Fermi liquid (NFL) effects. We overview the Kondo lattice model (KLM) which is believed to describe the physics of those systems. After recalling the existing theories based on large-N expansion and variou

Kirill N. Alekseev, Mikhael V. Erementchouk, Feodor V. Kusmartsev

We describe a novel effect of the generation of direct current which may arise in semiconductors or semiconductor microstructures due to a mixing of coherent electromagnetic radiations of commensurate frequencies. The effect is, in essence, due to a nonparabolicity of the electron energy bands and is stronger in systems where this nonparabolicity is greater.

Ludovic Berthier, Jean-Louis Barrat, Jorge Kurchan

The response function of domain growth processes, and in particular the violation of the fluctuation-dissipation theorem, are studied both analytically and numerically. In the asymptotic limit of large times, the fluctuation-dissipation ratio $X$, which quantifies this violation, tends to one if $C>m^2$ and to zero if $C<m^2$, corresponding to the fast (`bul

R. Bundschuh, T. Hwa

The statistical mechanics of heteropolymer structure formation is studied in the context of RNA secondary structures. A designed RNA sequence biased energetically towards a particular native structure (a hairpin) is used to study the transition between the native and molten phase of the RNA as a function of temperature. The transition is driven by a competit

Alexander N. Korotkov, Konstantin K. Likharev

A new method of electronic refrigeration based on resonant Fowler-Nordheim emission is proposed and analyzed. In this method, a bulk emitter is covered with a-few-nm-thick film of a widegap semiconductor, creating an intermediate step between electron energies in the emitter and in vacuum. An external electric field tilts this potential profile, forming a qu

B. Stern, Ya. Tikhomirova, M. Stepanov, D. Kompaneets

We present preliminary results of an off-line search for non-triggered gamma-ray bursts (GRBs) in the BATSE daily records for about 5.7 years of observations. We found more GRB-like events than the yield of the similar search of Kommers et al. (1998) and extended the Log N - log P distribution down to $\sim$ 0.1 ph cm$^{-2}$ s$^{-1}$. The indication of a tur

Kenneth J. Mighell

Applying the standard weighted mean formula, [sum_i {n_i sigma^{-2}_i}] / [sum_i {sigma^{-2}_i}], to determine the weighted mean of data, n_i, drawn from a Poisson distribution, will, on average, underestimate the true mean by ~1 for all true mean values larger than ~3 when the common assumption is made that the error of the ith observation is sigma_i = max(

C. G. De Pree, M. Nysewander, W. M. Goss

NGC 3576 (G291.28-0.71; l=291.3o, b=-0.7o) and NGC 3603 (G291.58-0.43; l=291.6o, b=-0.5o) are optically visible, luminous HII regions located at distances of 3.0 kpc and 6.1 kpc, respectively. We present 3.4 cm Australian Telescope Compact Array (ATCA) observations of these two sources in the continuum and the H90a, He90a, C90a and H113b recombination lines

Ramon Khanna

I study the generation and evolution of magnetic fields in the plasma surrounding a rotating black hole. Attention is focused on effects of the gravitomagnetic potential. The gravitomagnetic force appears as battery term in the generalized Ohm&#39;s law. The generated magnetic field should be stronger than fields generated by the classical Biermann battery.

G. S. Bisnovatyi-Kogan

The launch of the Beppo-Sax satellite gave a unique opportunity to investigate gamma ray bursts (GRB) in different spectral regions. The large diversity of the afterglow behavior creates additional problems for the cosmological model with a fireball. Formation of the afterglow giving the observed diversity of properties is suggested in the Galactic neutron s

S. V. Molkov, S. A. Grebenev, M. N. Pavlinsky, R. A. Sunyaev

We present results of observations of the known LMXB source GX3+1 with the telescope ART-P on board GRANAT in the fall of 1990. A strong X-ray burst was detected from the source on Oct. 14 when it was in the low X-ray state with a luminosity ~30% smaller than the normal one. That was only the second case for the whole history of its study when it exhibited s

J. Quinn, I. H. Bond, P. J. Boyle, S. M. Bradbury

The BL Lacertae object Markarian 501 was identified as a source of gamma-ray emission at the Whipple Observatory in March 1995. Here we present a flux variability analysis on several times-scales of the 233 hour data set accumulated over 213 nights (from March 1995 to July 1998) with the Whipple Observatory 10 m atmospheric Cherenkov imaging telescope. In 19

J. -M. Alimi, J. Perez, A. Serna

We study the stability of rotating collisionless self-gravitating spherical systems by using high resolution N-body experiments on a Connection Machine CM-5. We added rotation to Ossipkov-Merritt (hereafter OM) anisotropic spherical systems by using two methods. The first method conserves the anisotropy of the distribution function defined in the OM algorith

D. Fargion, Yu. A. Golubkov, M. Yu. Khlopov, R. V. Konoplich

The 4th generation of fermions predicted by the phenomenology of heterotic string models can possess new strictly conserved charge, which leads, in particular, to the hypothesis of the existence of the 4th generation massive stable neutrino. The compatibility of this hypothesis with the results of underground experiment DAMA searching for weakly interactive

S. Capozziello, G. Iovane

Pixel lensing is a technique for searching baryonic components of dark matter, (MACHOs), in any part of galaxies. This method is very efficient, since it avoids to resolve each source star and so it has the advantage to provide an high statistic. Taking into account the fact that this technique is very time expensive in data analysis phase and the present te

Sethi Meetu, Batra Annu, Lohiya Daksh

&#34;Power Law Cosmologies&#34; are defined by their growth of the cosmological scale factor as $ t^α$ regardless of the matter content or cosmological epoch. Constraints from the current age of the Universe and from the high redshift supernovae data require ``large&#39;&#39; $α$ ($\approx 1$). We reinforce this by latest available observations. Such a large

I. Georgantopoulos, I. Papadakis, R. S. Warwick, D. A. Smith

We present Rossi X-ray Timing Explorer, monitoring observations of the Seyfert 2 galaxy Markarian 3 spanning a 200 day period during which time the source flux varied by a factor $\sim 2$ in the 4-20 keV bandpass. In broad agreement with earlier Ginga results, the average spectrum can be represented in terms of a simple spectral model consisting of a very ha

S. Biswas, B. Modak, A. Shaw

Using the wormhole dominance proposal, it is shown that quantum corrections to the usual WKB ansatz for the wave function of the universe ably circumvent many of the drawbacks present in the current proposals. We also find that the recent criticism by Hawking and Turok does not apply to the tunneling proposal.

Roberto B. Salgado

After a brief review of classical probability theory (measure theory), we present an observation (due to Sorkin) concerning an aspect of probability in quantum mechanics. Following Sorkin, we introduce a generalized measure theory based on a hierarchy of ``sum-rules.&#39;&#39; The first sum-rule yields classical probability theory, and the second yields a ge

Pierre Vanhove

We discuss the Matrix Model aspect of configurations saturating a fixed number of fermionic zero modes. This number is independent of the rank of the gauge group and the instanton number. This will allow us to define a large-$N_c$ limit of the embeddeding of $K$ D-instantons in the Matrix Model and make contact with the leading term (the measure factor) of t

Savdeep Sethi, Mark Stern

We study the effective action of quantum mechanical SU(N) Yang-Mills theories with sixteen supersymmetries and N>2. We show that supersymmetry requires that the eight fermion terms in the supersymmetric completion of the $v^4$ terms be one-loop exact. We also show that the twelve fermion terms in the supersymmetric completion of the $v^6$ terms are two-loop

Gabor Papp, Peter Levai, George Fai

Pion and photon production cross sections are analyzed in proton-proton and proton-nucleus collisions at energies 20 GeV < s^1/2 < 60 GeV. We separate the proton-proton and nuclear contributions to transverse-momentum broadening and suggest a new mechanism for the nuclear enhancement in the high transverse-momentum region.

Th. Proffen, R. G. DiFrancesco, S. J. L. Billinge, E. L. Brosha

The atomic pair distribution function (PDF) of stoichiometric LaMnO_3 has been measured. This has been fit with a structural model to extract the local Jahn-Teller distortion for an ideal Mn(3+)O_6 octahedron. These results are compared to Rietveld refinements of the same data which give the average structure. Since the local structure is being measured in t

Y. Strauss, L. P. Horwitz

The quantum mechanical description of the evolution of an unstable system defined initially as a state in a Hilbert space at a given time does not provide a semigroup (exponential) decay law. The Wigner-Weisskopf survival amplitude, describing reversible quantum transitions, may be dominated by exponential type decay in pole approximation at times not too sh

Steven B. Giddings

An S-matrix analog is defined for anti-de Sitter space by constructing ``in&#39;&#39; and ``out&#39;&#39; states that asymptote to the timelike boundary. A derivation parallel to that of the LSZ formula shows that this ``boundary S-matrix&#39;&#39; is given directly by correlation functions in the boundary conformal theory. This provides a key entry in the A

W. Dür, J. I. Cirac, R. Tarrach

We present a family of 3--qubit states to which any arbitrary state can be depolarized. We fully classify those states with respect to their separability and distillability properties. This provides a sufficient condition for nonseparability and distillability for arbitrary states. We generalize our results to $N$--particle states.

Shinsuke Kawai, Jiro Soda

We study the evolution of fluctuations in a universe dominated by a scalar field coupled to the Gauss-Bonnet term. During the graceful exit, we found non-negligible enhancements of both curvature perturbation and gravitational wave in the long wavelength limit, and we also found a short wavelength instability for steep background superinflation just after th

Xu Zhou, Jian-sheng Chen, Wen Xu, Mei Zhang

The purpose of this paper is to present a method to self-calibrate the spectral energy distribution (SED) of objects in a survey based on the fitting of an SED library to the observed multi-color photometry. We adopt for illustrative purposes the Vilnius (Strizyz and Sviderskiene 1972) and Gunn & Stryker (1983) SED libraries. The self-calibration technique c

P. Braun-Munzinger, I. Heppe, J. Stachel

An improved statistical model with excluded volume corrections and resonance decays is introduced and applied to the complete presently available set of particle ratios as measured by the various experiments at the SPS in Pb+Pb collisions. The results imply that a high degree of hadrochemical equilibration is reached at chemical freeze-out in Pb+Pb collision

Somshubhro Bandyopadhyay, Guruprasad Kar, Anirban Roy

We discuss disentanglement of pure bipartite quantum states within the framework of the schemes developed for entanglement splitting and broadcasting of entanglement.

Denvil Smith

Wormhole routing, the latest switching technique to be utilized by massively parallel computers, enjoys the distinct advantage of a low latency when compared to other switching techniques. This low latency is due to the nearly distance insensitive routing traits in the absence of channel contention. The low latency of wormhole routing brings about a liabilit

Richard Easther, Gerald Guralnik, Stephen Hahn

We develop a new representation for the integrals associated with Feynman diagrams. This leads directly to a novel method for the numerical evaluation of these integrals, which avoids the use of Monte Carlo techniques. Our approach is based on based on the theory of generalized sinc ($\sin(x)/x$) functions, from which we derive an approximation to the propag

T. Olson, A. P. Young

We present results of Monte Carlo simulations of random bond Potts models in two dimensions, for different numbers of Potts states, q. We introduce a simple scheme which yields continuous self-dual distributions of the interactions. As expected, we find multifractal behavior of the correlation functions at the critical point and obtain estimates of the expon

O. B. Fringer, D. D. Holm

We study confined solutions of certain evolutionary partial differential equations (pde) in 1+1 space-time. The pde we study are Lie-Poisson Hamiltonian systems for quadratic Hamiltonians defined on the dual of the Lie algebra of vector fields on the real line. These systems are also Euler-Poincare equations for geodesic motion on the diffeomorphism group in

M. J. Martins

We use the braid-monoid algebra to construct integrable mixed vertex models. The transfer matrix of a mixed SU(N) model is diagonalized by nested Bethe ansatz approach.

V. E. Vekslerchik

The question of constructing the finite genus quasiperiodic solutions for the Ablowitz-Ladik hierarchy (ALH) is considered by establishing relations between the ALH and the Fay&#39;s identity for the theta-functions. It is shown that using a limiting procedure one can derive from the latter an infinite number of differential identities which can be arranged

V. I. Man&#39;ko, G. Marmo

We use the fact that some linear Hamiltonian systems can be considered as ``finite level&#39;&#39; quantum systems, and the description of quantum mechanics in terms of probabilities, to associate probability distributions with this particular class of linear Hamiltonian systems.

O. W. Greenberg, Robert C. Hilborn

The quon algebra gives a description of particles, ``quons,&#39;&#39; that are neither fermions nor bosons. The parameter $q$ attached to a quon labels a smooth interpolation between bosons, for which $q = +1$, and fermions, for which $q = -1$. Wigner and Ehrenfest and Oppenheimer showed that a composite system of identical bosons and fermions is a fermion i

R. Casadio, G. Venturi

The quantum mechanical evolution of an accelerated extended detector coupled to a massless scalar field is exhibited and the back-reaction due to emission or absorption processes computed at first order in the change of the detector&#39;s mass and acceleration. An analogy with black hole evaporation is found and illustrated.

Holger F. Hofmann, Ortwin Hess

We show that the reduction in photon number fluctuations at laser threshold often cited as a fundamental laser property does not occur in typical semiconductor lasers such as the ones commonly used in modern technological applications today. Indeed, such lasers may still exhibit thermal intensity fluctuations far above threshold. We therefore conclude that s

Shi-Hai Dong, Zhong-Qi Ma

Levinson&#39;s theorem for the one-dimensional Schrödinger equation with a symmetric potential, which decays at infinity faster than $x^{-2}$, is established by the Sturm-Liouville theorem. The critical case, where the Schrödinger equation has a finite zero-energy solution, is also analyzed. It is demonstrated that the number of bound states with even (odd)

Jess B. Sturgeon, Brian B. Laird

We present a new algorithm for isothermal-isobaric molecular-dynamics simulation. The method uses an extended Hamiltonian with an Andersen piston combined with the Nos&#39;e-Poincar&#39;e thermostat, recently developed by Bond, Leimkuhler and Laird [J. Comp. Phys., 151, (1999)]. This Nos&#39;e-Poincar&#39;e-Andersen (NPA) formulation has advantages over the

W. Wenzel, K. Hamacher

We investigate a novel stochastic technique for the global optimization of complex potential energy surfaces (PES) that avoids the freezing problem of simulated annealing by allowing the dynamical process to tunnel energetically inaccessible regions of the PES by way of a dynamically adjusted nonlinear transformation of the original PES. We demonstrate the s

K. Sakamoto, H. Kouno, A. Hasegawa, M. Nakano

The dispersion relations in the real and imaginary parts of the meson self-energies are studied to check the consistency of the &#34;renormalization&#34; in cutoff field theory. It is shown that the dispersion relations are preserved by the &#34;renormalization&#34;even if the finite cutoff and regulator are introduced in the calculation by hand.

Peter Kramer, Tobias Kramer

Exact one-electron eigenstates in finite parts of 1D periodic and Fibonacci chains of attractive and repulsive delta potentials are computed and analyzed. Bloch and bound state boundary conditions are related in terms of transfer matrices. Scenarios of positive and negative energy are distinguished. The dependence on the potential strength parameter is analy

Peter Kramer, Zorka Papadopolos, Harald Teuscher

Surfaces in i-Al68Pd23Mn9 as observed with STM and LEED experiments show atomic terraces in a Fibonacci spacing. We analyze them in a bulk tiling model due to Elser which incorporates many experimental data. The model has dodecahedral Bergman clusters within an icosahedral tiling T^*(2F) and is projected from the 6D face-centered hypercubic lattice. We deriv

Yurii M. Burman

Let M and N be even-dimensional oriented real manifolds, and $u:M \to N$ be a smooth mapping. A pair of complex structures at M and N is called u-compatible if the mapping u is holomorphic with respect to these structures. The quotient of the space of u-compatible pairs of complex structures by the group of u-equivariant pairs of diffeomorphisms of M and N i

Hans Plesner Jakobsen, Hechun Zhang

We investigate the algebra $F_q(N)$ introduced by Faddeev, Reshetikhin and Takhadjian. In case $q$ is a primitive root of unity the degree, the center, and the set of irreducible representations are found. The Poisson structure is determined and the De Concini-Kac-Procesi Conjecture is proved for this case. In the case of $q$ generic, the primitive ideals ar

David McKinnon

For any algebraic variety $V$ defined over a number field $k$, and ample height function $H$ on $V$, one can define the counting function $N_V(B) = #{P\in V(k) \mid H(P)\leq B}$. In this paper, we calculate the counting function for Kummer surfaces $V$ whose associated abelian surface is the product of elliptic curves. In particular, we effectively construct

G. Laumon, J. L. Waldspurger

Paper withdrawn. There is a gap in the proof of Proposition 4.3 (its conclusion ``d&#39;où la proposition.&#39;&#39; is incorrect). Therefore theorems 1.1 and 3.1, which were the main results of the paper, are not proved.

Anne Schilling, Mark Shimozono

We prove a bosonic formula for the generating function of level-restricted paths for the infinite families of affine Kac-Moody algebras. In affine type A this yields an expression for the level-restricted generalized Kostka polynomials.

C. Ciliberto, K. Hulek

One of the simplest examples of a smooth, non degenerate surface in P^4 is the quintic elliptic scroll. It can be constructed from an elliptic normal curve E by joining every point on E with the translation of this point by a non-zero 2-torsion point. The same construction can be applied when E is replaced by a (lineaerly normally embedded) abelian variety A

J. L. Cortes, J. Gamboa, I. Schmidt, J. Zanelli

New non-perturbatives excitations in the massless Thirring and Schwinger models are discussed.

A. H. Chamseddine, W. A. Sabra

BPS electric and magnetic black hole solutions which break half of supersymmetry in the theory of N=2 five-dimensional supergravity are discussed. For models which arise as compactifications of M-theory on a Calabi-Yau manifold, these solutions correspond, respectively, to the two and five branes wrapping around the homology cycles of the Calabi-Yau compact

G. A. Diamandis, B. C. Georgalas, N. E. Mavromatos, E. Papantonopoulos

Within the context of a super-critical (Liouville) string, we discuss (target-space) two-dimensional string cosmology. A numerical analysis indicates that the identification of time with the Liouville mode results in an expanding universe with matter which exhibits an inflationary phase, and `graceful exit&#39; from it, tending asymptotically to a flat-metri

R. Jackiw

In quantum field theory radiative corrections can be finite but undetermined.

Stefan Forste, Debashis Ghoshal, Stefan Theisen

We study stringy fluctuations as a source for corrections to the Wilson loop as obtained from the superstrings on (adS_5 x S^5)/ N=4 SYM correspondence. We give a formal expression in terms of determinants of two dimensional operators for the leading order correction.

G. Dall&#39;Agata, D. Fabbri, C. Fraser, P. Fre&#39;

We derive the free Osp(8|4) singleton action by sending the M2brane to the Minkowski boundary of an AdS_4x{\cal M}_7 background. We do this by means of the solvable Lie algebra parametrization of the coset space. We also give some comments on singleton actions from membranes on AdS_4xG/H backgrounds.

V. Barger, K. Whisnant

We make a global vacuum neutrino oscillation analysis of solar neutrino data, including the seasonal and energy dependence of the recent Super-Kamiokande 708-day results. The best fit parameters for ν_e oscillations to an active neutrino are δm^2 = 4.42\times10^{-10} eV^2, \sin^2 2θ= 0.93. The allowed mixing angle region is consistent with bi-maximal mixing

R. N. Mohapatra

A simultaneous understanding of the results of the LSND experiment indicating $ν_μ-ν_e$ oscillation together with other evidences for neutrino oscillations from solar and atmospheric neutrino data seems to require the existence of at least one sterile neutrino. One can also give other plausible astrophysical arguments that seem to require light sterile neutr

M. Beneke, A. Signer, V. A. Smirnov

We consider top-anti-top production near threshold in $e^+ e^-$ collisions, resumming Coulomb-enhanced corrections at next-to-next-to-leading order (NNLO). We also sum potentially large logarithms of the small top quark velocity at the next-to-leading logarithmic level using the renormalization group. The NNLO correction to the cross section is large, and it

Stephen P. Martin, James D. Wells

A Higgs boson with mass below 150 GeV has a total decay width of less than 20 MeV into accessible Standard Model states. This narrow width means that the usual branching fractions for such a light Higgs boson are highly susceptible to any new particles to which it has unsuppressed couplings. In particular, there are many reasonable and interesting theoretica

Ikaros Bigi, Nikolai Uraltsev

Pauli Interference in decays of heavy flavor mesons, a genuinely nonleptonic nonperturbative effect, is considered in the &#39;t Hooft model. Analytic summation of the exclusive decay widths yields the same expression as obtained in the OPE-based approach. Threshold-related violations of local duality in PI are found to be suppressed. A novel case is identif

S. Kraml

The first chapter serves as an introduction to the MSSM. I briefly review the model and explain why stops and sbottoms provide an interesting playground for exploring and testing this model. In the second chapter I discuss stop and sbottom production at lepton colliders. I give the analytical formulae for the production cross sections at e+e- and mu+mu- coll

B. V. Martemyanov

The following lectures concern with the quark structure of hadrons made up from light quarks. The symmetries of strong interaction were the only instruments used for the description of this structure. The models of hadrons (there are a lot of them) were not considered. There was not also considered the structure of hadrons with heavy quarks. The first round

Stephon Alexander, Robert Brandenberger, Richard Easther, Andrew Sornborger

We study the interaction between monopoles and embedded domain walls in a O(3) linear sigma model. We discover that there is an attractive force between the monopole and the wall. We provide evidence that after the monopole and domain wall collide, the monopole unwinds on the wall, and that the winding number spreads out on the surface. These results support

P. Butera, M. Comi

We have computed through order $β^{21}$ the high-temperature expansions for the nearest-neighbor spin correlation function $G(N,β)$ of the classical N-vector model, with general N, on the simple-cubic and on the body-centered-cubic lattices. For this model, also known in quantum field theory as the lattice O(N) nonlinear sigma model, we have presented in pre

Kenji Abe et al

The structure of e+e- -> b bbar g events was studied using Z0 decays recorded in the SLD experiment at SLAC. Three-jet final states were selected and the CCD-based vertex detector was used to identify two of the jets as b or bbar. Distributions of the gluon energy and polar angle were measured over the full kinematic range for the first time, and compared wi

Hermann Staengle, representing the SLD Collaboration

We present a preliminary direct measurement of the parity violating coupling of the Z boson to strange quarks, A_s, derived from a sample of approximately 300,000 hadronic decays of Z bosons produced with a polarized electron beam and recorded by the SLD experiment at SLAC between 1993 and 1997. Events with primary strange quarks are tagged by the presence i

Manfred Paulini

We review the status of bottom quark physics at the CDF experiment. The measurements reported are based on about 110 pb-1 of data collected at the Fermilab Tevatron pp= Collider operating at sqrt{s} = 1.8 TeV. In particular, we review results on B hadron lifetimes, measurements of the time dependence of B0 B0= oscillations, and a search for CP violation in B

Theodore C. Quinn, Robert M. Wald

For smooth solutions to Maxwell&#39;s equations sourced by a smooth charge-current distribution $j_a$ in stationary, asymptotically flat spacetimes, one can prove an energy conservation theorem which asserts the vanishing of the sum of (i) the difference between the final and initial electromagnetic self-energy of the charge distribution, (ii) the net electr

Pierre B. A. Lecomte, Michel Rigo

Generalizations of linear numeration systems in which the set of natural numbers is recognizable by finite automata are obtained by describing an arbitrary infinite regular language following the lexicographic ordering. For these systems of numeration, we show that ultimately periodic sets are recognizable. We also study the translation and the multiplicatio