August 1998 arXiv papers

Zohar Nussinov, Joseph Rudnick, Steven A. Kivelson, L. N. Chayes

Long-range frustrating interactions, even if their strength is infinitesimal, can give rise to a dramatic proliferations of ground or near-ground states. As a consequence, the ordering temperature can exhibit a discontinuous drop as a function of the frustration. A simple model of the doped Mott insulator, where the short-range tendency of the holes to phase

A. C. Layden, L. A. Ritter, D. L. Welch, T. M. A. Webb

We present time-series VI photometry of the metal-rich ([Fe/H] = -0.53) globular cluster NGC 6441. Our color-magnitude diagram shows that the extended blue horizontal branch seen in Hubble Space Telescope data exists in the outermost reaches of the cluster. The red clump slopes nearly parallel to the reddening vector. A component of this slope is due to diff

Lee Smolin

We show that there is a sector of quantum general relativity which may be expressed in a completely holographic formulation in terms of states and operators defined on a finite boundary. The space of boundary states is built out of the conformal blocks of SU(2)_L + SU(2)_R, WZW field theory on the n-punctured sphere, where n is related to the area of the bou

Jens O. Andersen, Michael Strickland

A homogeneous non-relativistic Bose gas is investigated at finite temperature using renormalization group methods. The phase transition is shown to be second order and the effective chemical potential and the effective quartic coupling vanish at the critical temperature. We obtain the critical exponent $ν=0.73$ at leading order in the derivative expansion.

A. Lima-Santos

The semiclassical limit of the algebraic quantum inverse scattering method is used to solve the theory of the Gaudin model. Via Off-shell Bethe ansatz equations of an integrable representation of the graded osp(1|2) vertex model we find the spectrum of N-1 independent Hamiltonians of Gaudin. Integral representations of the N-point correlators are presented a

William T. Reach, Jeonghee Rho

We report the detection of shock-excited far-infrared emission of H2O, OH, and CO from the supernova remnant 3C 391, using the ISO Long-Wavelength Spectrometer. This is the first detection of thermal H2O and OH emission from a supernova remnant. For two other remnants, W~28 and W~44, CO emission was detected but OH was only detected in absorption. The observ

M. Neubert, J. L. Rosner

A bound on the angle gamma of the unitarity triangle is derived using experimental information on the CP-averaged branching ratios for the rare decays B^+- -> pi^+- K^0 and B^+- -> pi^0 K^+-. The theoretical description is cleaner than the Fleischer-Mannel analysis of the decays B^+- -> pi^+- K^0 and B^0 -> pi^-+ K^+- in that the two decay rates differ only

Gérard Clément

The classical Einstein--Maxwell field equations admit static horizonless wormhole solutions with only a circular cosmic string singularity. We show how to extend these static solutions to exact rotating asymptotically flat solutions. For a suitable range of parameter values, these solutions describe charged or neutral rotating closed cosmic strings, with a p

P. De Los Rios, Y. -C. Zhang

We introduce a model able to reproduce the main features of 1/f noise: hyper-universality (the power-law exponents are independent on the dimension of the system; we show here results in d=1,2) and apparent lack of a low-frequency cutoff in the power spectrum. Essential ingredients of this model are an activation-deactivation process and dissipation.

H. Niggemann, J. Zittartz

We construct the exact ground state for an antiferromagnetic spin-3/2 model on the two-leg ladder as an optimum ground state. The ground state contains a discrete parameter "sigma"=+/-1 and a continuous parameter "a" which controls z-axis anisotropy. For most values of "a" the global ground state is unique. It has vanishing sublattice

Patrick Bruno, Hiroyoshi Itoh, Junichiro Inoue, Shinji Nonoyama

The effect of disorder on the perpendicular magnetoresistance of magnetic multilayers is investigated theoretically. Various kinds of disorder are considered: (i) interface substitutional disorder and (ii) bulk disorder in the various layers and in the leads. The calculations are based upon the non-equilibrium Green's function formalism, together with th

Ernest Ma, Martti Raidal, Utpal Sarkar

We explore the possible exotic particle content beyond the standard model by examining all its scalar bilinear combinations. We categorize these exotic scalar fields and show that without the suppression of (A) their Yukawa couplings with the known quarks and leptons, and (B) the trilinear couplings among themselves, most are already constrained to be very h

Robert Graham

The phase diffusion of the order parameter of trapped Bose-Einstein condensates at temperatures large compared to the mean trap frequency is determined, which gives the fundamental limit of the line-width of an atom laser. In addition a prediction of the correlation time of the number fluctuations in the condensate is made and related to the phase diffusion

A. Di Giacomo, M. D'Elia, H. Panagopoulos, E. Meggiolaro

Gauge invariant correlators in QCD are studied on the lattice.A Systematic determination of the correlation lengths for gluon field strength correlators and quark correlators is made.The measurement of the gluon and quark condensates is discussed.

K. Kobayashi, T. Mizokawa, A. Fujimori, M. Isobe

We have made an angle-resolved photoemission study of a one-dimensional (1D) Mott-Hubbard insulator Na_{0.96}V_{2}O_{5} and found that the spectra of the V 3d lower Hubbard band are strongly dependent on the temperature. We have calculated the one-particle spectral function of the one-dimensional t-J model at finite temperatures by exact diagonalization and

A. Edery, M. B. Paranjape

Using Penrose diagrams the causal structure of the static spherically symmetric vacuum solution to conformal (Weyl) gravity is investigated. A striking aspect of the solution is an unexpected physical singularity at $r=0$ caused by a linear term in the metric. We explain how to calculate the deflection of light in coordinates where the metric is manifestly c

Koji Hashimoto

We study the three-pronged strings (three string junctions) from the point of view of D-string worldsheet gauge theory. We justify interpreting kink solutions in the 2-dimensional gauge theory as pronged strings by examining BPS energy bounds obtained from this theory. When the ends of the pronged string are on D3-branes, the configuration preserves 1/4 supe

M. Dunajski, L. J. Mason, N. M. J. Woodhouse

We explain how to construct solutions to the self-dual Einstein vacuum equations from solutions of various two-dimensional integrable systems by exploiting the fact that the Lax formulations of both systems can be embedded in that of the self-dual Yang--Mills equations. We illustrate this by constructing explicit self-dual vacuum metrics on $\R^2\times Σ$, w

Fritz Gesztesy, Rudi Weikard

We provide an overview of elliptic algebro-geometric solutions of the KdV and AKNS hierarchies, with special emphasis on Floquet theoretic and spectral theoretic methods. Our treatment includes an effective characterization of all stationary elliptic KdV and AKNS solutions based on a theory developed by Hermite and Picard.

Ronnie Dickson, Fritz Gesztesy, Karl Unterkofler

We continue a recently developed systematic approach to the Bousinesq (Bsq) hierarchy and its algebro-geometric solutions. Our formalism includes a recursive construction of Lax pairs and establishes associated Burchnall-Chaundy curves, Baker-Akhiezer functions and Dubrovin-type equations for analogs of Dirichlet and Neumann divisors. The principal aim of th

A. Lima-Santos, R. C. T. Ghiotto

We solve the spectrum pf the closed Temperley-Lieb quantum spin chains using the coordinate Bethe ansatz. These Hamiltonians are invariante under the quantum group $U_{q}[sl(2)]$

C. W. J. Beenakker

A general relationship is presented between the statistics of thermal radiation from a random medium and its scattering matrix S. Familiar results for black-body radiation are recovered in the limit S to 0. The mean photocount is proportional to the trace of 1-SS^dagger, in accordance with Kirchhoff's law relating emissivity and absorptivity. Higher mome

W. Dür, H. - J. Briegel, J. I. Cirac, P. Zoller

We study the use of entanglement purification for quantum communication over long distances. For distances much longer than the coherence length of a corresponding noisy quantum channel, the fidelity of transmission is usually so low that standard purification methods are not applicable. It is however possible to divide the channel into shorter segments that

Taksu Cheon, T. Shigehara

We construct a one-dimensional contact interaction ($ε$ potential) which induces the discontinuity of the wave function while keeping its derivative continuous. By combining the $ε$ potential and the Dirac's $δ$ function, we construct most general one-dimensional contact interactions allowable under the time reversal symmetry. We present some elementary

Gunn Quznetsov

The propositional logic is generalized on the real numbers field. The logical analog of the Bernoulli independent tests scheme is constructed. The variant of the nonstandard analysis is adopted for the definition of the logical function, which has all properties of the classical probability function. The logical analog of the Large Number Law is deduced from

Oscar Bolina, J. R. Parreira

We develop a new method to determine the acceleration of a block sliding down along the face of a moving wedge. We have been able to link the solution of this problem to that of the inclined plane problem of elementary physics, thus providing a simpler solution to it.

B. Kaulakys, D. Grauzhinis, G. Vilutis

Mapping equations of motion of the highly exited classical atom in a monochromatic field are generalized for the two-frequency microwave field. Analysis of the obtained equations indicates to the weak sensitivity of the position of the recently observed ionization peak near the main resonance to the frequency and amplitude of the additional microwave field.

J. C. Wells, B. Segev, J. Eichler

We discuss the two-center, time-dependent Dirac equation describing the dynamics of an electron during a peripheral, relativistic heavy-ion collision at extreme energies. We derive a factored form, which is exact in the high-energy limit, for the asymptotic channel solutions of the Dirac equation, and elucidate their close connection with gauge transformatio

B. R. Schlei

Experimental spectra of the CERN/SPS experiments NA44 and NA49 are fitted while using four different equations of state of nuclear matter within a relativistic hydrodynamic framework. For the freeze-out temperatures, $T_f = 139$ MeV and $T_f = 116$ MeV, respectively, the corresponding freeze-out hypersurfaces and Bose-Einstein correlation functions for ident

Arne Hoell, Pieter Maris, Craig D. Roberts

We demonstrate that the restoration of chiral symmetry at finite-T in a class of confining Dyson-Schwinger equation (DSE) models of QCD is a mean field transition, and that an accurate determination of the critical exponents using the chiral and thermal susceptibilities requires very small values of the current-quark mass: log_{10}(m/m_u) < -5. Other classes

S. B. Gerasimov

As a desirable supplement to the reaction $pp \to pp2γ$, proposed earlier (nucl-th/9712064 and references therein) to probe for the NN--decoupled dibaryon resonances we suggest to use for the same goal the radiative capture processes in mesoatoms of the deuterium which we consider to be especially feasible for further test and invesigation of possible low-ly

Nigel Boston, Charles Leedham-Green

We produce infinitely many finite 2-groups that do not embed with index 2 in any group generated by involutions. This disproves a conjecture of Lemmermeyer and restricts the possible Galois groups of unramified 2-extensions, Galois over the rationals, of quadratic number fields.

Nigel Boston

This is an updated and extended version of ANT-0024. We prove more special cases of the Fontaine-Mazur conjecture regarding p-adic Galois representations unramified at p, and we present evidence for and consequences of a generalization of it.

Hui Zhu

Let A be a supersingular abelian variety over a finite field k. We give an approximate description of the structure of the group A(k) of rational points of A over k in terms of the characteristic polynomial f of the Frobenius endomorphism of A relative to k. If f=g^e for a monic irreducible polynomial g and a positive integer e, we show that there is a group

Stephen S. Kudla, Michael Rapoport, Tonghai Yang

In this paper we construct a modular form f of weight one attached to an imaginary quadratic field K. This form, which is non-holomorphic and not a cusp form, has several curious properties. Its negative Fourier coefficients are non-zero precisely for neqative integers -n such that n >0 is a norm from K, and these coefficients involve the exponential integra

Maciej Dunajski

The Lax formulation of the hyper-Hermiticity condition in four dimensions is used to derive a potential that generalises Plebanski&#39;s second heavenly equation for hyper-Kahler 4-manifolds. A class of examples of hyper-Hermitian metrics which depend on two arbitrary functions of two complex variables is given. The twistor theory of four-dimensional hyper-H

B. Gross, B. Kostant, P. Ramond, S. Sternberg

Let B be a reductive Lie subalgebra of a semi-simple Lie algebra of the same rank both over the complex numbers. To each finite dimensional irreducible representation $V_λ$ of F we assign a multiplet of irreducible representations of B with m elements in each multiplet, where m is the index of the Weyl group of B in the Weyl group of F. We obtain a generaliz

Mikhail Grinenko

It is proved that a three-dimensional double cone is a birationally rigid variety. We also compute the group of birational automorphisms of such a variety. This work is based on the method of &#34;untwisting&#34; maximal singularities of linear system.

S. C. Power

A classification is given for (regular) positions of direct sums of two matroid algebras (unital algebraic limits of matrix algebras) in a matroid superalgebra, where the individual summands have index 2 in their associated corner algebra. A similar classification is obtained for positions of direct sums of 2-symmetric algebras and, in the odd case, for the

Joel David Hamkins, Andrew Lewis

Recently we have introduced a new model of infinite computation by extending the operation of ordinary Turing machines into transfinite ordinal time. In this paper we will show that the infinite time Turing machine analogue of Post&#39;s problem, the question whether there are supertask degrees between 0 and the supertask jump 0^jump, has in a sense both pos

Bruce K. Driver, Brian C. Hall

We use a variant of the classical Segal-Bargmann transform to understand the canonical quantization of Yang-Mills theory on a space-time cylinder. This transform gives a rigorous way to make sense of the Hamiltonian on the gauge-invariant subspace. Our results are a rigorous version of the widely accepted notion that on the gauge-invariant subspace the Hamil

Lee Smolin

Work in progress is described which aims to construct a background independent formulation of M theory by extending results about background independent states and observables from quantum general relativity and supergravity to string theory. A list of principles for such a theory is proposed which is drawn from results of both string theory and background i

T. Pengpan, P. Ramond

The light-cone little group, SO(9), classifies the massless degrees of freedom of eleven-dimensional supergravity, with a triplet of representations. We observe that this triplet generalizes to four-fold infinite families with the quantum numbers of massless higher spin states. Their mathematical structure stems from the three equivalent ways of embedding SO

K. Zarembo

Static color charges in Yang-Mills theory are considered in the Schrödinger picture. Stationary states containing color sources, interquark potential and confinement criterion are discussed within the framework based on integration over gauge transformations which projects the vacuum wave functional on the space of physical, gauge-invariant states.

Yuji Okawa, Tamiaki Yoneya

As a continuation of our previous work on the multi-body forces of D-particles in supergravity and Matrix theory, we investigate the problem of motion. We show that the scattering of D-particles including recoil derived in Matrix theory is precisely reproduced by supergravity with the discrete light-cone prescription up to the second order in 11 dimensional

Sergei V. Ketov

A four-dimensional N=2 supersymmetric non-linear sigma-model with the Eguchi-Hanson (ALE) target space and a non-vanishing central charge is rewritten to a classically equivalent and formally renormalizable gauged `linear&#39; sigma-model over a non-compact coset space in N=2 harmonic superspace by making use of an N=2 vector gauge superfield as the Lagrange

Kei-Ichi Kondo

I propose to reformulate the gauge field theory as the perturbative deformation of a novel topological quantum field theory. It is shown that this reformulation leads to quark confinement in QCD$_4$. Similarly, the fractional charge confinement is also derived in the strong coupling phase of QED$_4$. As a confinement criterion, we use the area decay of the e

A. Ghinculov, T. Binoth

We discuss the current picture of the standard model&#39;s scalar sector at strong coupling. We compare the pattern observed in the scalar sector in perturbation theory up to two-loop with the nonperturbative solution obtained by a next-to-leading order 1/N expansion. In particular, we analyze two resonant Higgs scattering processes, ff -> H -> f&#39;f&#39;

A. Ghinculov, T. Binoth

We present a calculation of the three-point functions of the O(N)-symmetric sigma model. The calculation is done nonperturbatively by means of a higher-order 1/N expansion combined with a tachyonic regularization which we proposed in previous publications. We use the results for calculating the standard model process ff -> H -> WW nonperturbatively in the qu

R. Escribano

Central pseudoscalar production in $pp$ scattering is suppressed at small values of $Q_\perp$. Such a behavior is expected if the production occurs through the fusion of two vectors. We argue that an extension of the experiment could probe the gluon contribution to the proton spin.

Sergio Scopetta, Vicente Vento, Marco Traini

Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the polarized parton distributions by a convolution between constituent quark momentum distributions and constituent quark structure functions. We achieve good agreement with experiments in the unpolarized as well as in the polarized case, though a good

N. Arbex, M. Pluemer, R. M. Weiner

A multiparticle system produced by a large number of independent sources is described by a gaussian density matrix W. All theoretical approach to Bose-Einstein Correlatios Cn in high energy physics use this form for W. One of the most salient consequences of this form is the fact that all higher order (n>2) moments of the current distribution can be expresse

Fl. Stancu

We discuss the stability of multiquark systems containing heavy flavours. We show that the Goldstone boson exchange (GBE) model gives results at variance with the one-gluon-exchange (OGE) model, i.e. when the GBE model stabilizes a system the OGE model destabilizes it and vice-versa.

T. G. Steele, V. Elias

The current phenomenological determinations of $α_s(M_τ)$ and $α_s(M_Z)$ are shown to be only marginally consistent with the QCD evolution of the strong coupling constant between $M_Z$ and $M_τ$. This motivates a revised estimate of $α_s(M_τ)$ since the perturbative series used to extract $α_s(M_τ)$ from the $τ$ hadronic width exhibits slow convergence. Padé

P. Ramond

We present a model which contains three Abelian symmetries beyond the standard model. One is anomalous {\it \` a la} Green-Schwarz, and family-independent; the other two are family symmetries. All are broken at a large scale by stringy effects. The model is predictive in the neutrino sector: large mixing between $ν_μ-ν_τ$, and {\cal O}$(λ^3)$ $ν_e-ν_μ$ mixin

P. Ramond

A gauged phase symmetry with its anomalies cancelled by a Green-Schwarz mechanism, broken at a large scale by an induced Fayet-Iliopoulos term, is a generic feature of a large class of superstring theories. It induces many desirable phenomenological features: Yukawa coupling hierarchy, the emergence of a small Cabibbo-like expansion parameter, relating the W

Gilberto Colangelo, Gino Isidori

We analyze the contributions to rare kaon decays mediated by flavor-changing Z-penguin diagrams in a generic low-energy supersymmetric extension of the Standard Model. In order to perform a model-independent analysis we expand the squark mass matrices around the diagonal, following the so called mass-insertion approximation. We argue that in the present case

E. Levin

This talk is an attempt to clarify for experimentalists what we (theorists) mean when we are saying &#34;Pomeron&#34;. I hope, that in this talk they will find answers to such questions as what is Pomeron, what we have learned about Pomeron, both experimentally and theoretically, what is correct strategy to study Pomeron experimentally and etc. I also hope t

A. Bueno, M. Campanelli, A. Rubbia

We study the feasibility of performing a $ν_μ$ disappearance long-baseline experiment using a neutrino beam coming from muon decays. The advantage of such a technique with respect to the production of neutrino beams from pions is that in a muon decay both muon and electron neutrinos are produced in the same quantity. In case of $ν_μ\toν_{τ,s}$ oscillations,

E. Levin

This paper is written for &#34;Gribov Memorial Volume&#34;, Heavy Ion Physics, Acta Physica Hungarica. This is a report on my 25 years activity in understanding of the Pomeron structure. Since I was involved in the Pomeron business moreless from the beginning, I hope, that this report shows the development of the main ideas in their historical perspective fr

A. Ringwald, F. Schrempp

The present status of our ongoing systematic study of the discovery potential of QCD-instanton induced events in deep-inelastic scattering at HERA is briefly reviewed. We emphasize our recent progress in predicting the cross-sections of instanton-induced processes. Our finalized predictions include a dramatic improvement of the residual renormalization-scale

I. M. Dremin

The difference between the ratio of multiplicities and the ratio of their derivatives on energy for gluon and quark jets is calculated up to next-to-next-to leading order of perturbative QCD. Its non-zero value is uniquely defined by the running property of the QCD coupling constant. It is shown that this difference is rather small compared to values which c

Markus Diehl, Thierry Gousset, Bernard Pire

We show that the leading twist contribution to exclusive electroproduction of transversely polarized vector mesons vanishes at all orders in perturbation theory. Therefore one cannot extract information on the quark transversity distribution of the nucleon from this reaction. In turn one has that the produced vector meson is purely longitudinal in the large-

Ji-Ho Jang

We propose a new method to extract a CP angle $γ$ from semi-inclusive two-body nonleptonic decays, b ---> D^0(\bar{D}^0) s and b ---> D_{CP} s. This method is free from the unknown long distance strong interaction effects and gives theoretically cleaner signal than the similar method using exclusive nonleptonic decays, B ---> D K. We can determine $γ$ with 4

J. Engels, T. Scheideler

We calculate the critical amplitudes of the Polyakov loop and its susceptibility at the deconfinement transition of (3+1) dimensional SU(2) gauge theory. To this end we study the corrections due to irrelevant exponents in the scaling functions. As a guiding line for determining the critical amplitudes we use envelope equations which we derive from the finite

E871 Collaboration, J. Belz, M. Diwan, M. Eckhause

We describe the development and testing of a novel beam stop for use in a rare kaon decay experiment at the Brookhaven AGS. The beam stop is located inside a dipole spectrometer magnet in close proximity to straw drift chambers and intercepts a high-intensity neutral hadron beam. The design process, involving both Monte Carlo simulations and beam tests of al

The OPAL Collaboration, G. Abbiendi et al

A selection of di-lepton events with significant missing transverse momentum has been performed using a total data sample of 77.0 pb-1 at e+e- centre-of-mass energies of 161 GeV, 172 GeV and 183 GeV. The observed numbers of events: four at 161 GeV, nine at 172 GeV, and 78 at 183 GeV, are consistent with the numbers expected from Standard Model processes, whi

Pankaj K. Agarwal, Joseph O&#39;Rourke

Problems presented at the open-problem session of the 14th Annual ACM Symposium on Computational Geometry are listed.

Aldo H. Romero, David W. Brown, Katja Lindenberg

We apply weak-coupling perturbation theory to the Holstein molecular crystal model in order to compute an electron-phonon correlation function characterizing the shape and size of the polaron lattice distortion in one, two, and three dimensions. This correlation function is computed exactly to leading order in the electron-phonon coupling constant, permittin

P. W. Brouwer

A d.c. current can be pumped through a quantum dot by periodically varying two independent parameters $X_1$ and $X_2$, like a gate voltage or magnetic field. We present a formula that relates the pumped current to the parametric derivatives of the scattering matrix $S(X_1,X_2)$ of the system. As an application we compute the statistical distribution of the p

Alistair Savage, Ian Affleck

A large-n approximation to the S=1 antiferromagnetic chain, using the symmetric tensor representation and its conjugate, is developed to order 1/n in order to calculate the magnon wave-function and to study the effect of modifying the exchange coupling from J to J&#39; on a single link. It is shown that a magnon boundstate exists below the Haldane gap for ar

G. Ghosh, V. S. Sastry, T. S. Radhakrishnan

We report intermolecular potential-energy calculations for solid C_${70}$ and determine the optimum static orientations of the molecules at low temperature; we find them to be consistent with the monoclinic structural model proposed by us in an earlier report [Solid State Commun. {\bf 105), 247 (1998)]. This model indicates that the C_5 axis of the molecule

Yuli V. Nazarov

We find that tunnel junctions are not needed to provide single electron effects in a metallic island. Eventually the tunnel junction may be replaced by an arbitrary scatterer. It is important that even a {\it diffusive} scatterer provides a sufficient isolation for single electron effects to persist. To formulate this in exact terms, we derive and analyze th

A. J. Nederveen, Yuli V. Nazarov

We have investigated the effect of weak disorder on the ground state of a two dimensional electron gas in the quantum Hall regime at filling factors slightly deviating from unity. The skyrmions and antiskyrmions are found to be present even at filling factor $ν=1$. They may be strongly squeezed by the disorder. We have studied temperature effect on skyrmion

A. V. Khaetskii, Yuli V. Nazarov

We investigated theoretically the Coulomb drag effect in coupled 2D electron gases in a wide interval of magnetic field and temperature $ 1/τ\ll ω_c \ll E_F/\hbar$, $T \ll E_F$, $τ$ being intralayer scattering time, $ω_c$ being the cyclotron frequency. We show that the quantization of the electron spectrum leads to rich parametric dependences of drag transre

Yoshihiko Nonomura

We propose a new efficient scheme for the quantum Monte Carlo study of quantum critical phenomena in quantum spin systems. Rieger and Young&#39;s Trotter-number-dependent finite-size scaling in quantum spin systems and Ito {\it et al.}&#39;s evaluation of the transition point with the non-equilibrium relaxation in classical spin systems are combined and gene

K. B. Lauritsen, P. Frojdh, M. Howard

We present a general scaling theory for the surface critical behavior of non-equilibrium systems with phase transitions into absorbing states. The theory allows for two independent surface exponents which satisfy generalized hyperscaling relations. As an application we study a generalized version of directed percolation with two absorbing states. We find two

Mark-Jan Nederhof, Giorgio Satta

The Earley algorithm is a widely used parsing method in natural language processing applications. We introduce a variant of Earley parsing that is based on a ``delayed&#39;&#39; recognition of constituents. This allows us to start the recognition of a constituent only in cases in which all of its subconstituents have been found within the input string. This

R. Mansilla, G. Cocho

Based on a model first studied in [Physical Review A, vol. 43, 5240-5260,1991] properties of correlation function for expansion-modification systems are developed. The existence of several characteristic exponents is proved. The relationship of this fact with long-range correlation in DNA is stablished. Comparison between theoretical exponents and those obta

Gaspar Galaz, Valerie de Lapparent

We briefly show results on the redshift and space distribution of field galaxies with different spectral types in the ESO-Sculptor survey (ESS). We also show results on the ESS galaxy luminosity function.

Karen O&#39;Neil, G. D. Bothun, J. Schombert

Although numerous simulations have been done to understand the effects of intense bursts of star formation on high surface brightness galaxies, few attempts have been made to understand how localized starbursts would affect both the color and surface brightness of low surface brightness (LSB) galaxies. To remedy this, we have run 53 simulations involving bur

F. Crawford, V. M. Kaspi, R. N. Manchester, F. Camilo

Using the Parkes radio telescope, we have searched for pulsed radio emission from the recently discovered X-ray pulsars AX J1811.5-1926 and PSR J0537-6910 in the supernova remnants G11.2-0.3 and N157B, respectively. We detected no significant pulsed radio emission from these pulsars and have set an upper limit of 0.07 mJy on the 1374 MHz flux from AX J1811.5

L. Gregorini, M. Vigotti, K. -H. Mack, J. Zoennchen

We present radio continuum data for 1050 B3 radio sources at 10.6 GHz. These sources constitute the B3-VLA sample which is complete down to 100 mJy at 408 MHz. The aim is the construction of a homogeneous spectral database for a large sample of radio sources, 10 times fainter than the K&#34;uhr et al. (1981) sample, in the range 151 MHz to 10.6 GHz. Extended

Mario Vietri, Luigi Stella

We present a scenario (SupraNova) for the formation of GRBs occurring when a supramassive neutron star (SMNS) loses so much angular momentum that centrifugal support against self--gravity becomes impossible, and the star implodes to a black hole. This may be the baryon--cleanest environment proposed so far, because the SN explosion in which the SMNS formed s

Kyu-Hyun Chae, Valery K. Khersonsky, David A. Turnshek

We present an analytical formulation of gravitational lensing using familiar triaxial power-law mass distributions, where the 3-dimensional mass density is given by $ρ(X,Y,Z) = ρ_0 [1 + (\frac{X}{a})^2 + (\frac{Y}{b})^2 + (\frac{Z}{c})^2]^{-ν/2}$. The deflection angle and magnification factor are obtained analytically as Fourier series. We give the exact exp

M. V. Sazhin, A. V. Toporensky

The cosmic microwave background (CMB) polarization, whose experimental detection must become the next natural step in the study of the CMB radiation, depends on the dynamics of hydrogen recombination in the Universe, on the relation between the power of scalar perturbations and gravitational waves, and on the presence or absence of secondary ionization. The

Willy Kley

In numerical computations of astrophysical flows one frequently has to deal with situations which require the use of a corotating coordinate system. Then, in addition to the centrifugal force, the Coriolis terms have to be included in the Navier-Stokes equations. In usual numerical treatments of solving the equations of motion these non-inertial forces are i

Alexander Knebe

The formation process, properties, and spatial distribution of galaxy groups and clusters are closely related to the background cosmological model. We use numerical simulations of variants of the CDM model with different cosmological parameters in order to compare statistical measures such as mass spectra, merging histories, correlation functions, and cluste

Attila Grandpierre

I derive here a model independent inequality which shows that the problem of the missing beryllium neutrinos of the Sun roots in the fact that the SuperKamiokande contains a term arising from a non-pp,CNO source. First principle physics shows that the non-pp,CNO source is of thermonuclear runaway origin. Several indications suggest that the non-pp,CNO term p

Attila Grandpierre

I point out that the all the arguments against an astrophysical solution do not exclude a yet not recognised class of solar models, in which an explosive energy source is present in the solar core besides the standard pp and CNO cycle. It is shown from first principle physics that stars have a non-pp,CNO source: local thermonuclear runaways. I derive a model

J. -M. Hameury, J. -P. Lasota, G. Dubus

We calculate the effect of illumination of dwarf nova accretion discs by radiation from a hot, central, white dwarf. We show that only for very hot white dwarfs (Teff ~ 40 000$ K) the inner region of quiescent dwarf nova discs are partially depleted so that the delay between the rise to outburst of the optical and UV fluxes would be increased as suggested re

Takashi Hamana

We investigate the performance of the optimized Post-Zel&#39;dovich approximation in three cold dark matter cosmologies. We consider two flat models with $Ω_0=1$ (SCDM) and with $Ω_0=0.3$ ($Λ$CDM) and an open model with $Ω_0=0.3$ (OCDM). We find that the optimization scheme proposed by Weiß, Gottlöber & Buchert (1996), in which the performance of the Lagrang

Cong Xu, Richard Tuffs

Based on new ISO mid-infrared observations and ground based $H_α$ and near-infrared observations, we report the detection of a bright starburst in the intragroup medium (IGM) of the famous compact group of galaxies Stephan&#39;s Quintet (Source A in Fig.1). We demonstrate that this starburst is caused by a collision between a high velocity ($δ$V$\sim$ 1000 k

L. F. Rodriguez, I. F. Mirabel

In 1994 February-August we observed with the VLA four ejection events of radio emitting clouds from the high energy source GRS 1915+105. These events are all consistent with anti-parallel ejections of twin pairs of clouds moving away from the compact source at $\sim$ 0.92 of the speed of light and angles of $\sim$ 70$^{\circ}$ with respect to the line of sig

Kay Joerg Wiese, Pierre Le Doussal

We study the dynamics of a polymer or a D-dimensional elastic manifold diffusing and convected in a non-potential static random flow (the ``randomly driven polymer model&#39;&#39;). We find that short-range (SR) disorder is relevant for d < 4 for directed polymers (each monomer sees a different flow) and for d < 6 for isotropic polymers (each monomer sees th

Changhyun Ahn, Hoil Kim, Hyun Seok Yang

We study M theory on $AdS_7 \times \RP^4$ corresponding to 6 dimensional SO(2N) $(0, 2)$ superconformal field theory on a circle which becomes 5 dimensional super Yang-Mills theory at low energies. For SU(N) (0,2) theory, a wrapped D4 brane on $§^4$ which is connected to a D4 brane on the boundary of $AdS_7$ by N fundamental strings can be interpreted as bar

Harvendra Singh

In this note we extend our work in a previous paper hep-th/9801038. We show here that various intersecting brane-like configurations can be found in the vacuum of $D=4, N=4$ supergravity with gauged R-symmetry group $SU(2)\times SU(2)$. These include intersections of domain-walls, strings and point-like objects. Some of these intersecting configurations pres

Boris A. Rodriguez, Augusto Gonzalez, Luis Quiroga, Roberto Capote

Second order perturbation theory and a Lipkin-Nogami scheme combined with an exact Monte Carlo projection after variation are applied to compute the ground-state energy of $6\le N\le 210$ electron-hole pairs confined in a parabolic two-dimensional quantum dot. The energy shows nice scaling properties as N or the confinement strength is varied. A crossover fr

Phil Gossett

This paper shows how to design efficient arithmetic elements out of quantum gates using &#34;carry-save&#34; techniques borrowed from classical computer design. This allows bit-parallel evaluation of all the arithmetic elements required for Shor&#39;s algorithm, including modular arithmetic, deferring all carry propagation until the end of the entire computa

Eshel Ben-Jacob, Ziv Hermon, Shay Caspi

Based on the understanding that chemical bonds can act as tunnel junctions in the Coulomb blockade regime, and on the technical ability to coat a DNA strand with metal, we suggest that DNA can be used to built logical devices. We discuss two explicit examples: a Single Electron Tunneling Transistor (SET) and a Quantum Bit Element. These devices would be lite