July 1996 arXiv papers — page 9

R. Eder, Y. C. Chen, H. Q. Lin, Y. Ohta

We present an exact diagonalization study of the low energy singlet and triplet states for both 1D and 2D t-J model. A scan of the parameter ratio J/t shows that for nearly all low energy states in both 1D and 2D the excitation energy takes the linear form E(t,J) = a t + b J. In 1D this is the natural consequence of the factorization of the low energy wave f

A Fledderjohann, K H Mütter, M Karbach, G Müller

The impact of the non-2-spinon excitations of the one-dimensional $S=1/2$ Heisenberg antiferromagnet on the integrated intensity, the susceptibility, the frequency moments, and the Euclidian time representation of the $T=0$ dynamic spin structure factor $S(q,ω)$ is studied on the basis of finite-size data for chains with up to $N=28$ sites.

P. W. Brouwer, C. W. J. Beenakker

Motivated by recent experiments by Den Hartog et al., we present a random-matrix theory for the magnetoconductance fluctuations of a chaotic quantum dot which is coupled by point contacts to two superconductors and one or two normal metals. There are aperiodic conductance fluctuations as a function of the magnetic field through the quantum dot and $2π$-perio

C. B. Whan, J. White, T. P. Orlando

We numerically calculated the full capacitance matrices for both one-dimensional (1D) and two-dimensional (2D) quantum-dot arrays. We found it is necessary to use the full capacitance matrix in modeling coupled quantum dot arrays due to weaker screening in these systems in comparison with arrays of normal metal tunnel junctions. The static soliton potential

C. B. Whan, T. P. Orlando

We report a numerical study of transport properties of a quantum dot with superconducting leads. We introduce a general phenomenological model of quantum dot transport, in which electron tunnel rates are computed within the Fermi's Golden Rule approach. The low temperature current-voltage (I-V) characteristics are in qualitative agreement with experiment

Pierrette Bouillon

This paper focusses on mental state adjectives and offers a unified analysis in the theory of Generative Lexicon (Pustejovsky, 1991, 1995). We show that, instead of enumerating the various syntactic constructions they enter into, with the different senses which arise, it is possible to give them a rich typed semantic representation which will explain both th

Sabine Lehmann, Stephan Oepen, Sylvie Regnier-Prost, Klaus Netter

The TSNLP project has investigated various aspects of the construction, maintenance and application of systematic test suites as diagnostic and evaluation tools for NLP applications. The paper summarizes the motivation and main results of the project: besides the solid methodological foundation, TSNLP has produced substantial multi-purpose and multi-user tes

C. Uhlig, J. Eggers

We consider cascade models of turbulence which are obtained by restricting the Navier-Stokes equation to local interactions. By combining the results of the method of extended self-similarity and a novel subgrid model, we investigate the inertial range fluctuations of the cascade. Significant corrections to the classical scaling exponents are found. The dyna

P. Goldoni, C. Musso

We examine a sample of detected and undetected Isolated Neutron Stars (INSs), selected on the basis of their energy loss and distance, in order to maximize their detection probability. Since the sample we consider encompasses more upper limits than detections, we make use, for the first time in this field of astronomy, of survival analysis procedures through

R. A. Vázquez

We review the problem of fluctuations in particle shower theory. By using a generalization of Furry equation, we find relations between the $n$--particle correlation function and the number of particles average or 1--particle correlation function. Such relations show that the average is the only independent dynamical variable. We also develop a numerical cod

V. Celebonovic

Nine years ago,working within the framework of theoretical dense matter physics,the present author has determined the chemical composition of the Galileian satellites of Jupiter.A few months ago,in the flyby of the GA- LILEO spaceprobe,some of the theoretical predictions were confirmed.

Yoshiaki Fukuma

Let $X$ be a smooth projective surface over the complex number field and let $L$ be a nef-big divisor on $X$. Here we consider the following conjecture; If the Kodaira dimension $κ(X)\geq 0$, then $K_{X}L\geq 2q(X)-4$, where $q(X)$ is the irregularity of $X$. In this paper, we prove that this conjecture is true if (1) the case in which $κ(X)=0$ or 1, (2) the

M. E. J. Newman

Statistical analysis indicates that the fossil extinction record is compatible with a distribution of extinction events whose frequency is related to their size by a power law with an exponent close to two. This result is in agreement with predictions based on self-organized critical models of extinction, and might well be taken as evidence of critical behav

M. Levy, S. Solomon

Multiplicative random processes in (not necessaryly equilibrium or steady state) stochastic systems with many degrees of freedom lead to Boltzmann distributions when the dynamics is expressed in terms of the logarithm of the normalized elementary variables. In terms of the original variables this gives a power-law distribution. This mechanism implies certain

D. H. Brown, D. H. Orlov, G. S. Varner, W. A. Worstell

The performance of a scintillating fiber (2mm diameter) position sensitive detector ($4.8 \times 4.8$ cm$^2$ active area) for the single bremstrahlung luminosity monitor at the VEPP-2M electron-positron collider in Novosibirsk, Russia is described. Custom electronics is triggered by coincident hits in the X and Y planes of 24 fibers each, and reduces 64 PMT

Roland Stumpf

First principles calculations show that H overlayers induce a honeycomb vacancy reconstruction on Al(111). Above one ML H coverage, Al(111) facets into surfaces vicinal to (111), with {100} faceted single and double steps and vacancies on the {111} terraces. These H induced reconstructions are stable because H binds more strongly to {100} than to {111} facet

C. C. Briggs

A general expression is given for the quintic Lovelock tensor as well as for the coefficient of the quintic Lovelock Lagrangian in terms of the Riemann-Christoffel and Ricci curvature tensors and the Riemann curvature scalar for n-dimensional differentiable manifolds having a general linear connection.

A. Iorio, L. O'Raifeartaigh, I. Sachs, C. Wiesendanger

Scale-invariant actions in arbitrary dimensions are investigated in curved space to clarify the relation between scale-, Weyl- and conformal invariance on the classical level. The global Weyl-group is gauged. Then the class of actions is determined for which Weyl-gauging may be replaced by a suitable coupling to the curvature (Ricci gauging). It is shown tha

A. Leike, S. Riemann

Expectations for constraints on extra Z bosons are derived for LEP 2 and future linear e+e- colliders. For typical GUTs, a Z' with M_{Z'} \le 3 to 6 \sqrt{s} may cause observable effects. The Z' discovery limits are dominated by statistical errors. However, if a Z' signal is observed, the discrimination between different models becomes much w

Gary Gibbons, Renata Kallosh, Barak Kol

We show that under variation of moduli fields $ϕ$ the first law of black hole thermodynamics becomes $dM = {κdA\over 8π} + ΩdJ + ψdq + χdp - Σdϕ$, where $Σ$ are the scalar charges. We also show that the ADM mass is extremized at fixed $A$, $J$, $(p,q)$ when the moduli fields take the fixed value $ϕ_{\rm fix}(p,q)$ which depend only on electric and magnetic c

Alain Lascoux, Bernard Leclerc, Jean-Yves Thibon

We investigate certain bases of Hecke algebras defined by means of the Yang-Baxter equation, which we call Yang-Baxter bases. These bases are essentially self-adjoint with respect to a canonical bilinear form. In the case of the degenerate Hecke algebra, we identify the coefficients in the expansion of the Yang-Baxter basis on the usual basis of the algebra

Michio Kaku

We re-examine the question of the stability of quantum supermembranes. In the past, the instability of supermembranes was established by using a regulator, i.e. approximating the membrane by SU(N) super Yang-Mills theory and letting $N \rightarrow \infty$. In this paper, we (a) show that the instability persists even if we directly examine the continuum theo

A. Marshakov, A. Mironov, A. Morozov

The prepotential $F(a_i)$, defining the low-energy effective action of the $SU(N)$ ${\cal N}=2$ SUSY Yang-Mills theories, satisfies an enlarged set of the WDVV-like equations $F_iF_k^{-1}F_j = F_jF_k^{-1}F_i$ for any triple $i,j,k = 1,\ldots,N-1$, where matrix $F_i$ is equal to $(F_i)_{mn} = \partial^3 F/\partial a_i\partial a_m\partial a_n$. The same equati

D. V. Long, G. M. Shore

In a recent paper, general solutions for the vacuum wave functionals in the Schrodinger picture were given for a variety of classes of curved spacetimes. Here, we describe a number of simple examples which illustrate how the presence of spacetime boundaries influences the vacuum wave functional and how physical quantities are independent of the choice of spa

Richard A. Matzner, Mijan Huq, Alonso Botero, Dae Il Choi

By writing the complete set of $3 + 1$ (ADM) equations for linearized waves, we are able to demonstrate the properties of the initial data and of the evolution of a wave problem set by Alcubierre and Schutz. We show that the gauge modes and constraint error modes arise in a straightforward way in the analysis, and are of a form which will be controlled in an

Rangan Lahiri

We explore the motion of a classical particle in a symmetric potential with non-Gaussian skewed white noise. We show analytically and numerically that the presence of nonzero odd moments leads to a macroscopic current. For a noise with a vanishing third moment we find that the current changes sign as the potential or the noise strength is increased. Possible

A. S. Alexandrov, V. V. Kabanov, N. F. Mott

We propose a microscopic theory of the `$c$'-axis and in-plane transport of copper oxides based on the bipolaron theory and the Boltzmann kinetics. The fundamental relationship between the anisotropy and the spin susceptibility is derived, $ρ_{c}(T,x)/ρ_{ab}(T,x)\sim x/\sqrt{T}χ_{s}(T,x)$. The temperature $(T)$ and doping $(x)$ dependence of the in-plane

J. Machta, K. Moriarty

The Lorentz lattice gas is studied from the perspective of computational complexity theory. It is shown that using massive parallelism, particle trajectories can be simulated in a time that scales logarithmically in the length of the trajectory. This result characterizes the ``logical depth" of the Lorentz lattice gas and allows us to compare it to other

Victor S. L'vov, . Yu. L'vov, A. C. Newell, V. Zakharov

We develop expressions for the nonlinear wave damping and frequency correction of a field of random, spatially homogeneous, acoustic waves. The implications for the nature of the equilibrium spectral energy distribution are discussed

Victor S. L'vov, Itamar Procaccia

In this paper we derive here, on the basis of the NS eqs. a set of fusion rules for correlations of velocity differences when all the separation are in the inertial interval. Using this we consider the standard hierarchy of equations relating the $n$-th order correlations (originating from the viscous term in the NS eq.) to $n+1$'th order (originating fr

Tsvi Piran, Anupam Singh

We have laid down the formalism and techniques necessary for computing the multipole components in a spherical harmonic expansion for bursting sources given any specific power spectrum of density perturbations. Using this formalism we have explicitly computed and tabulated the expected first few multipole components for the GRB distribution using a Cold Dark

I. R. Klebanov, A. A. Tseytlin

We discuss the known microscopic interpretations of the Bekenstein-Hawking entropy for configurations of intersecting M-branes. In some cases the entropy scales as that of a massless field theory on the intersection. A different situation, found for configurations which reduce to 1-charge D=5 black holes or 2-charge D=4 black holes, is explained by a gas of

J. P. Wittmer, M. E. Cates, P. Claudin

We present a new approach to the modelling of stress propagation in static granular media, focussing on the conical sandpile constructed from a point source. We view the medium as consisting of cohesionless hard particles held up by static frictional forces; these are subject to microscopic indeterminacy which corresponds macroscopically to the fact that the

Juan J. Ruiz-Lorenzo

We study numerically the probability distribution of the Yang-Lee zeroes inside the Griffiths phase for the two dimensional site diluted Ising model and we check that the shape of this distribution is that predicted in previous analytical works. By studying the finite size scaling of the averaged smallest zero at the phase transition we extract, for two valu

S. M. Morgan, D. L. Welch

The discovery of a large number of beat Cepheids in the Large Magellanic Cloud in the MACHO survey, provides an opportunity to compare the characteristics of such Cepheids over a range of metallicities. We produced a large grid of linear nonadiabatic pulsation models using the OPAL opacity tables and with compositions corresponding to those of the Milky Way,

D. Yoshioka, A. H. MacDonald

A theory of transport in the quantum Hall regime is developed for separately contacted double-layer electron systems. Inter-layer tunneling provides a channel for equilibration of the distribution functions in the two layers and influences transport properties through the resulting influence on steady-state distribution functions. Resistences for various con

Olaf Lechtenfeld

I review the covariant quantization of the closed fermionic string with (2,2) extended world-sheet supersymmetry on R^{2,2}. Results on n-point scattering amplitudes are presented, for tree- and one-loop world-sheets with arbitrary Maxwell instanton number. I elaborate the connection between Maxwell moduli, spectral flow, and instantons. It is argued that th

Sergio Ferrara, Massimo Bianchi, Gianfranco Pradisi, Augusto Sagnotti

Four-dimensional supergravity theories are reinterpreted in a 12-dimensional F-theory framework. The O(8) symmetry of N=8 supergravity is related to a reduction of F-theory on T_8, with the seventy scalars formally associated, by O(8) triality, to a fully compactified four-form A_4. For the N=1 type I model recently obtained from the type IIB string on the Z

Richard F. Lebed

Concise variable transformations between the four angles of the CKM matrix in the standard representation advocated by the Particle Data Group and the angles of the unitarity triangles are derived. The behavior of these transformations in various limits is explored. The straightforward extension of this calculation to other representations and more generatio

A. Duncan, E. Eichten, H. Thacker

A method for computing electromagnetic properties of hadrons in lattice QCD is applied to the extraction of electromagnetic properties of the octet baryons. This allows a determination of the full dependence of the baryon masses on the charges and masses of the valence quarks. Results of a first numerical study (at $β=5.7$ with Wilson action and light quark

Wlodek Zadrozny

We introduce a method for analyzing the complexity of natural language processing tasks, and for predicting the difficulty new NLP tasks. Our complexity measures are derived from the Kolmogorov complexity of a class of automata --- {\it meaning automata}, whose purpose is to extract relevant pieces of information from sentences. Natural language semantics is

Fernando C. N. Pereira, Yoram Singer, Naftali Tishby

We describe, analyze, and evaluate experimentally a new probabilistic model for word-sequence prediction in natural language based on prediction suffix trees (PSTs). By using efficient data structures, we extend the notion of PST to unbounded vocabularies. We also show how to use a Bayesian approach based on recursive priors over all possible PSTs to efficie

R. Mauersberger, C. Henkel, N. Langer, Y. -N. Chin

The first detection of a $^{36}$S-bearing molecule in interstellar space is reported. The $J$=$2-1$ and $3-2$ transitions of C$^{36}$S have been observed toward eight Galactic molecular hot cores. From a comparison with other optically thin isotopic species of CS, the abundance ratio of $^{34}$S/$^{36}$S is 115$(\pm 17)$. This is smaller than the solar syste

Boris E. Stern, Roland Svensson

Although the time profiles of gamma ray bursts (GRBs) show extremely diverse behavior, their average statistical properties such as the average peak-aligned profile and the auto-correlation function show simple stretched-exponential behavior. This could indicate that the diversity of all bursts is just due to different random realizations of the same simple

Roland Svensson, Stefan Larsson, Juri Poutanen

We introduce a simple and convenient fitting formula for the thermal annihilation line from pair plasmas in cosmic sources. The fitting formula is accurate to 0.04\% and is valid at all photon energies and temperatures of interest. The commonly used Gaussian line profile is not a good approximation for broader lines.

Michael E. Flatte', Jeff M. Byers

The electronic structure near a single classical magnetic impurity in a superconductor is determined using a fully self-consistent Koster-Slater algorithm. Localized excited states are found within the energy gap which are half electron and half hole. Within a jellium model we find the new result that the spatial structure of the positive-frequency (electron

Alexander Braverman, Pavel Etingof, Dennis Gaitsgory

The purpose of this paper is to connect two subjects: the theory of quantum integrable systems (complete commutative rings of differential operators), and differential Galois theory. We define quantum completely integrable systems (QCIS), algebraically integrable QCIS, the differential Galois group of a QCIS. We show that the differential Galois group is alw

J. H. van Gorkom, C. L. Carilli, John T. Stocke, Eric S. Perlman

We present the results of a VLA and WSRT search for HI emission from the vicinity of seven nearby clouds, which were observed in Lya absorption with HST toward Mrk335, Mrk501 and PKS2155-304. We searched a volume of 40' x 40' x 1000 km/s. The HI mass sensitivity (5 sigma) varies from 5x10^6 to 5x10^8 Msun. We detected HI emission in the vicinity of f

R. Emparan

We analyze the zero mass black holes that arise as classical solutions to low energy heterotic string theory. Though these solutions contain naked singularities, it has been conjectured that they should be allowed in the theory. We find a solution describing a pair of oppositely charged massless black holes in uniformly accelerated motion under no external f

J. Schaffner, J. Bondorf, I. N. Mishustin

We discuss the equation of state of neutron stars in the dense interior considering hyperons and the possible onset of kaon condensation within the relativistic mean field model. We find that hyperons are favoured in dense matter and that their appearance make the existence of a kaon condensed phase quite unlikely. Implications for the recent measurements of

B. Boisseau, C. Charmousis, B. Linet

We assume that a self-gravitating thin string can be locally described by what we shall call a smoothed cone. If we impose a specific constraint on the model of the string, then its central line obeys the Nambu-Goto equations. If no constraint is added, then the worldsheet of the central line is a totally geodesic surface.

C. J. A. P. Martins, E. P. S. Shellard

We discuss friction-dominated vortex-string evolution using a new analytic model recently developed by the authors. By treating the average string velocity, as well as the characteristic lengthscale, as dynamical variables, we can provide a quantitative picture of the complete evolution of a vortex-string network. Previously known scaling laws are confirmed,

N. Menyhard, G. Odor

One-dimensional non-equilibrium kinetic Ising models evolving under the competing effect of spin flips at zero temperature and nearest-neighbour spin exchanges exhibiting directed percolation-like parity conserving(PC) phase transition on the level of kinks are now further investigated, numerically, from the point of view of the underlying spin system. Criti

Raimar Wulkenhaar

Starting with a Hilbert space endowed with a representation of a unitary Lie algebra and an action of a generalized Dirac operator, we develop a mathematical concept towards gauge field theories. This concept shares common features with the non--commutative geometry a la Connes/Lott, differs from that, however, by the implementation of unitary Lie algebras i

D. Korotkin, H. Samtleben

The mathematical framework for an exact quantization of the two-dimensional coset space sigma-models coupled to dilaton gravity, that arise from dimensional reduction of gravity and supergravity theories, is presented. Extending previous results the two-time Hamiltonian formulation is obtained, which describes the complete phase space of the model in the iso

Tomoko Kadoyoshi, Noriyuki Oshimo

In the supersymmetric standard model (SSM) the $W$-boson could have a non-vanishing electric dipole moment (EDM) through a one-loop diagram mediated by the charginos and neutralinos. Then the $W$-boson EDM induces the EDMs of the neutron and the electron. We discuss these EDMs, taking into consideration the constraints from the neutron and electron EDMs at o

M. Y. Choi, H. Y. Lee, D. Kim, S. H. Park

With a view to connecting random mutation on the molecular level to punctuated equilibrium behavior on the phenotype level, we propose a new model for biological evolution, which incorporates random mutation and natural selection. In this scheme the system evolves continuously into new configurations, yielding non-stationary behavior of the total fitness. Fu

Ori J. Ganor

We study compactifications of the $N=2$ 6D tensionless string on various complex two-folds down to two-dimensions. In the IR limit they become non-trivial conformal field theories in 2D. Using results of Vafa and Witten on the partition functions of twisted Super-Yang-Mills theories, we can study the resulting CFT. We also discuss the contribution of instant

Emory F. Bunn, Martin White

We present an analysis of the four-year data from the COBE DMR experiment. We use a Karhunen-Loeve expansion of the pixel data to calculate the normalization and goodness-of-fit of a range of models of structure formation. This technique produces unbiased normalization estimates and is capable of determining the normalization of any particular model with a s

Jerry Chance, the EOS-Collaboration

We study the energy dependence of collective (hydrodynamic-like) nuclear matter flow in 400-1970 A MeV Ni+Au and 1000-1970 A MeV Ni+Cu reactions. The flow increases with energy, reaches a maximum, and then gradually decreases at higher energies. A way of comparing the energy dependence of flow values for different projectile-target mass combinations is intro

Anne Schilling, S. Ole Warnaar

In a recent letter, new representations were proposed for the pair of sequences ($γ,δ$), as defined formally by Bailey in his famous lemma. Here we extend and prove this result, providing pairs ($γ,δ$) labelled by the Lie algebra A$_{N-1}$, two non-negative integers $\ell$ and $k$ and a partition $λ$, whose parts do not exceed $N-1$. Our results give rise to

J. I. Martin, M. Velez, F. Guinea, J. L. Vicent

The flux flow regime of high-T$_{\rm c}$ samples of different normal state resistivities is studied in the temperature range where the sign of the Hall effect is reversed. The scaling of the vortex viscosity with normal state resistivity is consistent with the Bardeen-Stephen theory. Estimates of the influence of possible mechanisms suggested for the sign re

K. Y. Szeto

The general scheme of data compression using the quantum noiseless coding theorem of Schumacher is dicussed for general quantum sources. When the Hilbert space of the quantum source is decomposable into orthogonal subspaces, one can first perform classical data compression before performing the quantum data compression for individual subspaces. For minimizin

M. J. Musolf, Hiroshi Ito

The nucleon's strange-quark vector current form factors are studied from the perspective of chiral symmetry. It is argued that chiral perturbation theory cannot yield a prediction for the strangeness radius and magnetic moment. Arrival at definite predictions requires the introduction of additional, model-dependent assumptions which go beyond the framewo

J. L. Friar

Weinberg's dimensional power counting for nuclei is reprised in this primer. The role of QCD and chiral symmetry in constructing effective Lagrangians is discussed. The two-scale hypothesis of Manohar and Georgi is combined with power counting in amplitudes to shed light on the scales of nuclear kinetic and potential energies, the size of strong-interact

D. Drechsel

Real and virtual Compton scattering has been and will be an important tool to study the structure of hadronic systems. We summarize the status of real Compton scattering and give an outlook at the new theoretical and experimental developments in the field of virtual Compton scattering.

Denny H. Leung

Let $\msp$ be a purely non-atomic measure space, and let $1 < p < \infty$. If $\weakLp\msp$ is isomorphic, as a Banach space, to $\weakLp\mspp$ for some purely atomic measure space $\mspp$, then there is a measurable partition $Ω= Ω_1\cupΩ_2$ such that $(Ω_1,Σ\capΩ_1,μ_{|Σ\capΩ_1})$ is countably generated and $σ$-finite, and that $μ(σ) = 0$ or $\infty$ for e

Edward Odell, Thomas Schlumprecht

It is proved that if a Banach space $X$ has a basis $(e_n)$ satisfying every spreading model of a normalized block basis of $(e_n)$ is 1-equivalent to the unit vector basis of $\ell_1$ (respectively, $c_0$) then $X$ contains $\ell_1$ (respectively, $c_0$). Furthermore Tsirelson&#39;s space $T$ is shown to have the property that every infinite dimensional sub

V. P. Frolov, D. V. Fursaev, A. I. Zelnikov

The statistical-mechanical origin of the Bekenstein-Hawking entropy $S^{BH}$ in the induced gravity is discussed. In the framework of the induced gravity models the Einstein action arises as the low energy limit of the effective action of quantum fields. The induced gravitational constant is determined by the masses of the heavy constituents. We established

Bertrand Le Roy

We introduce Z_3-graded objects which are the generalization of the more familiar Z_2-graded objects that are used in supersymmetric theories and in many models of non-commutative geometry. First, we introduce the Z_3-graded Grassmann algebra, and we use this object to construct the Z_3-matrices, which are the generalizations of the supermatrices. Then, we g

S. G. Rajeev

We show, using the large $N$ limit, that there is a non--trivial scale invariant action for four dimensional scalar field theory. We investigate the possibility that the scalar sector of the standard model of particle physics has such a scale invariant action, with scale invariance being spontaneously broken by the vacuum expectation value of the scalar. Thi

V. V. Bazhanov, S. L. Lukyanov, A. B. Zamolodchikov

We develop a method of computing the excited state energies in Integrable Quantum Field Theories (IQFT) in finite geometry, with spatial coordinate compactified on a circle of circumference R. The IQFT ``commuting transfer-matrices&#39;&#39; introduced by us (BLZ) for Conformal Field Theories (CFT) are generalized to non-conformal IQFT obtained by perturbing

I. L. Buchbinder, V. D. Pershin, G. B. Toder

We propose a method of constructing a gauge invariant canonical formulation for non-gauge classical theory which depends on a set of parameters. Requirement of closure for algebra of operators generating quantum gauge transformations leads to restrictions on parameters of the theory. This approach is then applied to bosonic string theory coupled to massive b

I. L. Buchbinder, V. D. Pershin, G. B. Toder

We propose a method of constructing a gauge invariant canonical formulation for non-gauge classical theory which depends on a set of parameters. Requirement of closure for algebra of operators generating quantum gauge transformations leads to restrictions on parameters of the theory. This approach is then applied for illustration to bosonic string theory cou

Raimar Wulkenhaar

We present the construction of the standard model within the framework of non--associative geometry. For the simplest scalar product we get the tree--level predictions $m_W=\frac{1}{2} m_t\,,$ $m_H=\frac{3}{2} m_t$ and $\sin^2 θ_W= \frac{3}{8}.$ These relations differ slightly from predictions derived in non--commutative geometry.

I. L. Buchbinder, A. Yu. Petrov

A new $N=1$ superfield theory in $D=4$ flat superspace is suggested. It describes dynamics of supergravity compensator and can be considered as a low-energy limit for $N=1$, $D=4$ superfield supergravity. The theory is shown to be renormalizable in infrared limit and infrared free. A quantum effective action is investigated in infrared domain.

J. Bijnens

This talk is an overview of Chiral Perturbation Theory for Kaon physics as far as not covered by other speakers. It includes a short introduction to the strengths and weaknesses of Chiral Perturbation Theory and its applications to semileptonic Kaon decays and $K\toππ(π)$.

Jean-Paul Blaizot, Edmond Iancu

The perturbative calculation of the lifetime of fermion excitations in a QED plasma at high temperature is plagued with infrared divergences which are not eliminated by the screening corrections. The physical processes responsible for these divergences are the collisions involving the exchange of longwavelength, quasistatic, magnetic photons, which are not s

C. D. Froggatt, H. B. Nielsen

We consider the application of the multiple point criticality principle to the pure Standard Model, with a desert up to the Planck scale. According to this principle, Nature should choose coupling constant values such that the vacuum can exist in degenerate phases. Furthermore we require a strongly first order phase transition between the two vacua, in order

A. Le Yaouanc, L. Oliver, O. Pène, J. -C. Raynal

We consider the dominant $c\bar{c}$ contribution to $ΔΓ$ for the $B_s^0$-$\bar{B}_s^0$ system in the heavy quark limit for both $b$ and $c$ quarks. In analogy with the Bjorken-Isgur-Wise sum rule in semileptonic heavy hadron decay, we impose duality between the parton model calculation of $ΔΓ$ and its estimation by a sum over heavy mesons. Varying the mass r

Thomas Mannel

An effective theory approach to heavy quarkonia decays based on the $1/m_Q$ expansion is introduced. Its application to decays in which the two heavy quarks annihilate is discussed.

Nima Arkani-Hamed, Christopher D. Carone, Lawrence J. Hall, Hitoshi Murayama

We propose a new framework for constructing supersymmetric theories of flavor, in which flavor symmetry breaking is triggered by the dynamical breakdown of supersymmetry at low energies. All mass scales in our scheme are generated from the supersymmetry breaking scale $Λ_{SSB} \approx 10^7$ GeV through radiative corrections. We assume a spontaneously broken

Claude Bernard, Tom Blum, Thomas A. DeGrand, Carleton DeTar

Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum numbers inaccessible to conventional quark-antiquark states. Confirmation of such states would give information on the role of &#34;dynamical&#34; color in low energy QCD. We present preliminary results for hybrid meson masses using light Wilson valence quarks.

Jesús Salas, Alan D. Sokal

We analyze the scaling and finite-size-scaling behavior of the two-dimensional 4-state Potts model. We find new multiplicative logarithmic corrections for the susceptibility, in addition to the already known ones for the specific heat. We also find additive logarithmic corrections to scaling, some of which are universal. We have checked the theoretical predi

S. Aid

Measurements are presented of $K^0$ meson and $Λ$ baryon production in deep-inelastic positron-proton scattering (DIS) in the kinematic range $10 < Q^2 < 70 $GeV$^2$ and $10^{-4} < x < 10^{-2}$. The measurements, obtained using the H1 detector at the HERA collider, are discussed in the light of possible mechanisms for increased strangeness production at low

A. Barvinsky, G. Kunstatter

Two arguments for the quantization of entropy for black holes in generic 2-D dilaton gravity are summarized. The first argument is based on reduced quantization of the only physical observables in the theory, namely the black hole mass and its conjugate momentum, the Killing time separation. The second one uses the exact physical mass eigenstates for Euclide

Jose-Luis Rosales

We develop the idea that, as a result of the arbitrariness of the factor ordering in Wheeler-DeWitt equation, gauge phases can not, in general, being completely removed from the wave functional in quantum gravity. The latter may be conveniently described by means of a remnant complex term in WDW equation depending of the factor ordering. Taking this equation

Yong Wang, A. H. MacDonald

We report on a microscopic calculation of the current and magnetic field distribution in the mixed state of model s-wave and d-wave superconductors. For the d-wave case, we find that corrections to London theory are important at fields small compared to $H_{c2}$. The field distribution is influenced by both superfluid-velocity dependence and non-locality in

Thomas C. Halsey, Katsuya Honda, Bertrand Duplantier

A recently proposed theory for diffusion-limited aggregation (DLA), which models this system as a random branched growth process, is reviewed. Like DLA, this process is stochastic, and ensemble averaging is needed in order to define multifractal dimensions. In an earlier work [T. C. Halsey and M. Leibig, Phys. Rev. A46, 7793 (1992)], annealed average dimensi

Carlo Presilla, Johannes Sjöstrand

We use an adiabatic approximation in terms of instantaneous resonances to study the steady-state and time-dependent transport properties of interacting electrons in biased resonant tunneling heterostructures. This approach leads, in a natural way, to a transport model of large applicability consisting of reservoirs coupled to regions where the system is desc

T. Jonsson, J. F. Wheater

We introduce a simple model for the size distribution of avalanches based on the idea that the front of an avalanche can be described by a directed random walk. The model captures some of the qualitative features of earthquakes, avalanches and other self-organized critical phenomena in one dimension. We find scaling laws relating the frequency, size and widt

Mulugeta Bekele, G. Ananthakrishna, N. Kumar

We examine the effect of subdividing the potential barrier along the reaction coordinate on Kramers&#39; escape rate for a model potential. Using the known supersymmetric potential approach, we show the existence of an optimal number of subdivisions that maximises the rate.

Keith Vander Linden, ; Barbara Di Eugenio

Building text planning resources by hand is time-consuming and difficult. Certainly, a number of planning architectures and their accompanying plan libraries have been implemented, but while the architectures themselves may be reused in a new domain, the library of plans typically cannot. One way to address this problem is to use machine learning techniques

Keith Vander Linden, Barbara Di Eugenio

In this paper, we define the notion of a preventative expression and discuss a corpus study of such expressions in instructional text. We discuss our coding schema, which takes into account both form and function features, and present measures of inter-coder reliability for those features. We then discuss the correlations that exist between the function and

Michael S. Turner

Detection of the gravitational waves excited during inflation as quantum mechanical fluctuations is a key test of inflation and crucial to learning about the specifics of the inflationary model. We discuss the potential of Cosmic Background Radiation (CBR) anisotropy and polarization and of laser interferometers such as LIGO, VIRGO/GEO and LISA to detect the

C. J. Pethick, Vesteinn Thorsson

We calculate the rate of energy emission by bremsstrahlung of neutrino pairs by electrons moving in the crystalline lattice of ions in dense matter in the crust of a neutron star. Since the periodic potential in the solid gives rise to electronic band gaps which can be as large as about 1 MeV, it is necessary in estimating the bremsstrahlung rate at low temp

Sabine Schindler, Joachim Wambsganss

An analysis of a ROSAT/HRI observation of the optically rich, gravitationally lensing galaxy cluster CL0500-24 (or Abell S0506) is presented. We show that the X-ray luminosity of this supposedly rich cluster is relatively low at $1.1^{+0.2}_{-0.1}\times10^{44}$ erg/s in the ROSAT band, the bolometric X-ray luminosity is $2.0^{+1.5}_{-0.7}\times 10^{44}$ erg/

Doris M. Neumann, Hans Boehringer

We present X-ray data on the distant cluster Cl0016+16 (z=0.5545) from ROSAT PSPC and HRI observations and use them to study the physics of the intracluster medium (ICM) and the dynamical state of the cluster. The surface brightness distribution is not only described by a spherically symmetric model but also by a two-dimensional $β$-model fit. Subtracting an

V. Zanchin, J. A. S. Lima, R. Brandenberger

The Zeldovich approximation is applied to study the accretion of hot and cold dark matter onto moving long strings. It is assumed that such defects carry a substantial amount of small-scale structure, thereby acting gravitationally as a Newtonian line source whose effects dominate the velocity perturbations. Analytical expressions for the turn-around surface

Joel Primack, Anatoly Klypin

Here we discuss what are perhaps the two most popular variants of CDM that might agree with the data: \lcdm\ and CHDM. While the predictions of COBE-normalized \lcdm\ and CHDM both agree well with the available data on scales of $\sim 10$ to $100 \hMpc$, each has potential virtues and defects. \lcdm\ with $\Omega_0 \sim 0.3$ has the possible virtue of allowi