July 1999 arXiv papers — page 14

R. K. Kaul

Topological quantum field theories can be used as a powerful tool to probe geometry and topology in low dimensions. Chern-Simons theories, which are examples of such field theories, provide a field theoretic framework for the study of knots and links in three dimensions. These are rare examples of quantum field theories which can be exactly (non-perturbative

Tomas Sykora

The two different approaches - Källen's and Brandt's methods - for the calculations of the Schwinger terms in the 1+1 dimensional Abelian and non-Abelian free current algebras are discussed. These methods are applied to calculation of the single and double commutators. The validity of the Jacobi identities is examined in 1+1 and 3+1 dimensions and in

R. Amorim, J. Barcelos-Neto

We extend superspace by introducing an antisymmetric tensorial coordinate. The resulting theory presents a supersymmetry with central charge. After integrating over the tensorial coordinate, an effective action describing massive bosons and fermions is explicitely derived for the spacetime dimension D=2. The adopted procedure is simpler than the Kaluza-Klein

A. Kovner, A. Krasnitz, R. Potting

We investigate the effect of dynamical fermions on the sphaleron transition rate at finite temperature for the Abelian Higgs model in one spatial dimension. The fermion degrees of freedom are included through bosonization. Using a numerical simulation, we find that massless fermions do not change the rate within the measurement accuracy. Surprisingly, the ex

Dimitri Bourilkov

A global analysis of the data on Bhabha scattering from the four LEP experiments ALEPH, DELPHI, L3 and OPAL is performed to search for effects of virtual graviton exchange in models with low scale gravity. No statistically significant deviations from the Standard Model expectations are observed and lower limits on the scale of models with large extra dimensi

A. Bartl, W. Majerotto, W. Porod

We show that the Higgs boson exchange contribution can be large in three-body decays of neutralinos even in the case of small tan(beta). This enlarges the branching ratios for the decays neutralino_2 -> neutralino_1 b \bar{b} and neutralino_2 -> neutralino_1 tau- tau+. This is the case in the region of the parameter space where the two lightest neutralinos a

J. Papavassiliou, K. Philippides

We present a new, model independent method for extracting bounds for the anomalous $γWW$ couplings from hadron collider experiments. At the partonic level we introduce a set of three observables which are constructed from the unpolarized differential cross-section for the process $d\bar{u}\to W^{-}γ$ by appropriate convolution with a set of simple polynomial

A. Bianconi, S. Boffi, R. Jakob, M. Radici

We give a general overview of the role and interpretation of fragmentation functions in hard processes. Transverse momentum dependence gives rise to time-reversal odd fragmentation functions contributing at leading order. Final state interactions are necessary to have non-zero time reversal odd functions. We present a model calculation for the special case o

Steven D. Bass

We derive the effective chiral Lagrangian for low energy eta--nucleon and eta'--nucleon interactions and show that gluonic degrees of freedom, via the axial anomaly, induce a contact term in the pp -> pp eta and pp -> pp eta' reactions. We then discuss the consequences for the extraction of g_{eta'NN} from experimental data.

Feng Yuan, Kuang-Ta Chao

Massless diquark jet and gluon jet productions at large transverse momentum in the coherent diffractive processes at hadron colliders are studied in the two-gluon exchange parametrization of the Pomeron model. We use the helicity amplitude method to calculate the cross section formulas. We find that for the light quark jet and gluon jet production the diffra

X. -H. Guo, A. W. Thomas

We study the possibility of obtaining large direct CP violation in the charmed hadron decays $D^+ \to \rho^+ \rho^0 (\omega) \to \rho^+ \pi^+\pi^-$, $D^+ \to \pi^+ \rho^0 (\omega) \to \pi^+ \pi^+\pi^-$, $D^0 \to \phi \rho^0 (\omega) \to\phi \pi^+\pi^-$, $D^0 \to\eta \rho^0 (\omega) \to\eta \pi^+\pi^-$, $D^0 \to \eta' \rho^0 (\omega) \to\eta' \pi^+\pi^-$, $D^

Ma Wen-Gan, Du Fei, Zhou Mian-Lai, Jiang Yi

The production of the lightest chargino pair from gluon-gluon fusion is studied in the minimal supersymmetric model(MSSM) at proton-proton colliders. We find that with the chosen parameters, the production rate of the subprocess can be over 2.7 femto barn when the chargino is higgsino-like, and the corresponding total cross section in proton-proton collider

V. Emel'yanov, A. Khodinov, S. R. Klein, R. Vogt

The effect of shadowing on the early state of ultrarelativistic heavy ion collisions and transverse energy production is discussed. Results are presented for RHIC Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV and LHC Pb+Pb collisions at $\sqrt{s_{NN}} = 5.5$ TeV.

Sacha Davidson, Toby Falk, Marta Losada

The Minimal Supersymmetric Standard Model has a candidate dark matter particle in its spectrum and may be able to generate the baryon asymmetry of the Universe (BAU) at the electroweak phase transition. In the Constrained MSSM, we find the area of parameter space which is allowed by accelerator and precision tests, which produces a relic dark matter abundanc

Juri Rolf, Ulli Wolff

A non perturbative finite size scaling technique is used to study a running coupling in lattice Yang-Mills theory coupled to a bosonic Wilson spinor field in the Schrödinger functional scheme. This corresponds to two negative flavours. The scaling behaviour in this case is compared to quenched results and to QCD with two flavours. The continuum limit is conf

Kurt Langfeld, Gwansoo Shin

SU(N_c) Yang-Mills theory is investigated at finite densities of N_f heavy quark flavors. The calculation of the (continuum) quark determinant in the large-mass limit is performed by analytic methods and results in an effective gluonic action. This action is then subject to a lattice representation of the gluon fields and computer simulations. The approach m

D0 Collaboration, B. Abbott

We present a preliminary measurement of the electron angular distribution parameter alpha2 in W to e nu events using data collected by the D0 detector during the 1994--1995 Tevatron run. We compare our results with next-to-leading order perturbative QCD, which predicts an angular distribution of 1 +/- alpha1 cos theta* +alpha_2 cos^2 theta*, where theta* is

WA89 Collaboration

We report on a measurement of the differential and total cross sections of inclusive production of Xi resonances in Sigma - nucleus collisions at 345 GeV/c.

A. P. Billyard, A. A. Coley, R. J. van den Hoogen, J. Ibanez

We investigate in detail the qualitative behaviour of the class of Bianchi type B spatially homogeneous cosmological models in which the matter content is composed of two non-interacting components; the first component is described by a barotropic fluid having a gamma-law equation of state, whilst the second is a non-interacting scalar field (phi) with an ex

J. Kondev, C. L. Henley, D. G. Salinas

We develop a new approach to characterizing the morphology of rough surfaces based on the analysis of the scaling properties of contour loops, i.e. loops of constant height. Given a height profile of the surface we perform independent measurements of the fractal dimension of contour loops, and the exponent that characterizes their size distribution. Scaling

V. J. Emery, S. A. Kivelson, J. M. Tranquada

Stripe phases are predicted and observed to occur in a class of strongly-correlated materials describable as doped antiferromagnets, of which the copper-oxide superconductors are the most prominent representative. The existence of stripe correlations necessitates the development of new principles for describing charge transport, and especially superconductiv

J. Heurich, M. G. Moore, P. Meystre

The trap environment in which Bose-Einstein condensates are generated and/or stored strongly influences the way they interact with light. The situation is analogous to cavity QED in quantum optics, except that in the present case, one tailors the matter-wave mode density rather than the density of modes of the optical field. Just as in QED, for short times,

Helim Aranda-Espinoza, Yi Chen, Nily Dan, TC Lubensky

A positively charged, mixed bilayer vesicle in the presence of negatively charged surfaces (for example, colloidal particles) can spontaneously partition into an adhesion zone of definite area, and another zone that repels additional negative objects. Although the membrane itself has nonnegative charge in the repulsive zone, negative counterions on the inter

T. Winiecki, J. F. McCann, C. S. Adams

Vortex structures in dilute quantum fluids are studied using the Gross-Pitaevskii equation. The velocity and momentum of multiply quantized vortex rings are determined and their core structures analysed. For flow past a spherical object, we study the encircling and pinned ring solutions, and determine their excitation energies as a function of the flow veloc

A. J. Millis, H. Monien

We use analytic and numerical methods to determine the density of states of a one-dimensional electron gas coupled to a spatially random quasi-static back-scattering potential of long correlation length. Our results provide insight into the 'pseudogap' phenomenon occurring in underdoped high-Tc superconductors, quasi-one-dimensional organic conductor

W. Geist, A. Idrizbegovic, M. Marinescu, T. A. B. Kennedy

We propose an efficient mechanism for the evaporative cooling of trapped fermions directly into quantum degeneracy. Our idea is based on an electric field induced elastic interaction between trapped atoms in spin symmetric states. We discuss some novel general features of fermionic evaporative cooling and present numerical studies demonstrating the feasibili

N. Akman, M. Tomak

The charge density and pair correlation function of three interacting electrons confined within a two-dimensional disc-like hard wall quantum dot are calculated by full numerical diagonalization of the Hamiltonian. The formation of a Wigner-molecule in the form of equilateral triangular configuration for electrons is observed as the size of the dot is increa

M. J. Konstantinovic, Z. V. Popovic, A. N. Vasil'ev, M. Isobe

We argue on the basis of symmetry selection rules and Raman scattering spectra that NaV$_2$O$_5$ undergoes a charge ordering phase transition at T$_c$=34 K. Such a transition is characterized by the redistribution of the charges at the phase transition and corresponds to the change of the vanadium ions, from uniform V$^{4.5+}$ to two different V$^{4+}$ and V

J. V. Andersen, D. Sornette

Based on a faithful representation of the heavy tail multivariate distribution of asset returns introduced previously (Sornette et al., 1998, 1999) that we extend to the case of asymmetric return distributions, we generalize the return-risk efficient frontier concept to incorporate the dimensions of large risks embedded in the tail of the asset distributions

Ingibjorg Magnusdottir, Vidar Gudmundsson

We investigate the effects of the shape of quantum dots on their far-infrared absorption in an external magnetic field by a model calculation. We focus our attention on dots with a parabolic confinement potential deviating from the common circular symmetry, and dots having circular doughnut shape. For a confinement where the generalized Kohn theorem does not

Yasuhiro Saiga, Yoshio Kuramoto

Dynamical properties, such as dynamical spin and charge structure factors and single-particle spectral functions, are studied for the one-dimensional supersymmetric t-J model with inverse-square interaction. Exact diagonalization and the recursion method are used for finite systems up to 16 sites. A simple rule is proposed to understand the supermultiplet st

Hagen Kleinert, Verena Schulte-Frohlinde

With the help of strong-coupling theory, we calculate the critical exponents of O(N)-symmetric phi^4-theories in 4- epsilon dimensions up to five loops with an accuracy comparable to that achieved by Borel-type resummation methods.

Andrew J. Dolgert

We study two superconducting systems using the Landau-Ginzburg equations. The first is a superconducting half-space with an applied magnetic field parallel to the surface. We calculate the maximum applied field that still supports superconductivity in the material by solving the Landau-Ginzburg equations analytically in asymptotic regimes of the Landau-Ginzb

John Cardy

We develop a field-theoretic representation for the configurations of an interface between two ordered phases of a q-state Potts model in two dimensions, in the solid-on-solid approximation. The model resembles the field theory of directed percolation and may be analysed using similar renormalisation group methods. In the one-loop approximation these reveal

R. Atkins, W. Benbow, D. Berley, M. -L. Chen

Previous works have shown that water Cherenkov detectors have superior sensitivity to those of scintillation counters as applied to detecting extensive air showers (EAS). This is in large part due to their much higher sensitivity to EAS photons which are more than five times more numerous than EAS electrons. Large area water Cherenkov detectors can be constr

Scott D. Horner, Marvin E. Germain, Thomas P. Greene, Fred H. Harris

FAME is designed to perform an all-sky, astrometric survey with unprecedented accuracy. It will create a rigid astrometric catalog of 4x10^7 stars with 5 < m_V < 15. For bright stars, 5 < m_V < 9, FAME will determine positions and parallaxes accurate to < 50 microarcseconds, with proper motion errors < 50 microarcseconds/year. For fainter stars, 9 < m_V < 15

Bradford B. Behr, S. G. Djorgovski, Judith G. Cohen, James K. McCarthy

We have determined the projected rotational velocities of thirteen blue horizontal-branch (BHB) stars in the globular cluster M13 via rotational broadening of metal absorption lines. Our sample spans the photometric gap observed in the horizontal branch distribution at Teff ~= 11000 K, and reveals a pronounced difference in stellar rotation on either side of

B. Mobasher, P. Mazzei

A new method is developed for estimating photometric redshifts, using realistic template SEDs, extending over four decades in wavelength (i.e from 0.05 $μm$ to 1 mm). The SEDs are constructed for four different spectral types of galaxies (elliptical, spiral, irregular and starburst) and satisfy the following characteristics: a). they are optimised to produce

M. Giard, E. Hivon, C. Nguyen, R. Gispert

We present simulations of observations with the 143 GHz channel of the Planck High Frequency Instrument (HFI). These simulations are performed over the entire sky, using the true angular resolution of this channel: 8 arcmin FWHM, 3.5 arcmin per pixel. We show that with measured 0.1 K bolometer performances, the sensitivity needed on the Cosmic Microwave Back

M. A. T. Groenewegen, M. Salaris

Using the method of ``reduced parallaxes&#39;&#39; for the Halo RR Lyrae stars in the Hipparcos catalogue we derive a zero point of 0.77 $\pm$ 0.26 mag for an assumed slope of 0.18 in the $M_{\rm V}$-[Fe/H] relation. This is 0.28 magnitude brighter than the value Fernley et al. (1998a) derived by employing the method of statistical parallax for the {\it iden

D. Kranich, O. C. De Jager, M. Kestel, E. Lorenz

The BL Lac Object Mkn 501 was in a state of high activity in the TeV range in 1997. During this time Mkn 501 was observed by all Cherenkov-Telescopes of the HEGRA-Collaboration. Part of the data were also taken during moonshine thus providing a nearly continuous coverage for this object in the TeV-range. We have carried out a QPO analysis and found evidence

R. J. Wilman, A. C. Fabian

Recent work by Risaliti et al.(1999) suggests that more than half of all Seyfert 2 galaxies in the local universe are Compton-thick (N_H > 10^24 cm^-2). This has implications for AGN synthesis models for the X-ray background (XRB), the flexibility of which for the inclusion of large numbers of high-z type 2 sources we examine here. We highlight the importanc

HongSheng Zhao, Kathryn Johnston, Lars Hernquist, David Spergel

ESA&#39;s Global Astrometric Interferometer for Astrophysics (GAIA) holds the promise of mapping out the detailed phase space structure of the Galactic halo by providing unprecedented annual proper motion and parallax of $1-10\muas$ astrometric accuracy (Gilmore et al. 1998). Unlike NASA&#39;s Space Interferometry Mission (SIM), which will achieve similar ac

Frank Verbunt

A brief overview is given of X-ray observations of old clusters. Most X-ray sources in old open clusters are interacting binaries, formed via evolution of a primordial binary, and emitting X-rays because of magnetic activity; however, a sizable fraction of the cluster sources is not well understood, including some of the most luminous ones. Globular clusters

S. Capozziello, G. Iovane

The long-standing issues of determination of the mass distribution and nature of the center of our Galaxy could be probed by a lensing experiment capable of testing the spatial and velocity distributions of stars nearby and beyond it. We propose a lensing toy-model which could be a further evidence that a massive condensation (eg a neutrino condensation) is

P. Richter, M. Hilker, T. Richtler

We present Stroemgren CCD photometry for the two galactic globular clusters M55 (NGC 6809) and M22 (NGC 6656). We find average Stroemgren metallicities of -1.71 dex for M55 and -1.62 dex for M22. The determination of metal abundances in cluster giants with the Stroemgren m1 index in comparison with spectroscopic data from Briley et al. (1993) and Norris & Fr

Klaus Dolag, Matthias Bartelmann, Harald Lesch

We perform cosmological, hydrodynamic simulations of magnetic fields in galaxy clusters. The computational code combines the special-purpose hardware Grape for calculating gravitational interaction, and smooth-particle hydrodynamics for the gas component. We employ the usual MHD equations for the evolution of the magnetic field in an ideally conducting plasm

Andreas Schaale

The main focus of this work is to understand the dynamics of non regulated markets. The present model can describe the dynamics of any market where the pricing is based on supply and demand. It will be applied here, as an example, for the German stock market presented by the Deutscher Aktienindex (DAX), which is a measure for the market status. The duality o

Saurya Das, Arundhati Dasgupta

We study the emission rates of scalar, spinor and vector particles from a 5 dimensional black hole for arbitrary partial waves. The solution is lifted to 6 dimensions, and the near horizon $ BTZ \times S^3$ geometry of the black hole solution is probed to determine the greybody factors. We show that the exact decay rates can be reproduced from a $(1+1)$-dime

R. J. McQueeney, J. L. Sarrao, J. S. Gardner, M. F. Hundley

The phonon densities-of-states of La(1.475)Nd(0.4)Sr(0.125)CuO(4) and La(1.9)Sr(0.1)CuO(4) were measured using inelastic neutron scattering. The ~70 meV phonon band which appears due to hole doping in La(1.9)Sr(0.1)CuO(4) is known to arise from strong electron-lattice coupling. This phonon band is strongly suppressed in the Nd-doped compound for which T_c is

Julie D. Blum

By assuming the existence of a novel multipronged string state for D-particles interacting with D-brane intersections in type IIA string theory, we are able to derive a quantum mechanical description of supersymmetric Reissner-Nordstrom black holes. A supersymmetric index calculation provides evidence for this conjecture. The quantum mechanical system become

Hooman Davoudiasl

We study Compton scattering, gamma e -> gamma e, in the context of the recent proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. It is shown that, with an ultraviolet cutoff $M_S \sim 1$ TeV for the effective gravity theory, the cross section for this process at the Next Linear Collider (NLC) deviates from the prediction of the Stand

D0 collaboration, B. Abbott

We report on a search for R-parity violating supersymmetry in p-pbar collisions at sqrt(s) = 1.8 TeV using the D0 detector at Fermilab. Events with at least two electrons and four or more jets were studied. We observe 2 events in 99 +- 4.4 pb-1 of data, consistent with the expected background of 1.8 +- 0.4 events. This result is interpreted within the framew

I. Ya. Aref&#39;eva, I. V. Volovich

It is shown by Connes, Douglas and Schwarz that gauge theory on noncommutative torus describes compactifications of M-theory to tori with constant background three-form field. This indicates that noncommutative gauge theories on more general manifolds also can be useful in string theory. We discuss a framework to noncommutative quantum gauge theory on Poisso

Adel Bilal, Chong-Sun Chu

According to the AdS/CFT correspondence,the d=4, N=4 SU(N) SYM is dual to the Type IIB string theory compactified on AdS_5xS^5. A mechanism was proposed previously that the chiral anomaly of the gauge theory is accounted for to the leading order in N by the Chern-Simons action in the AdS_5 SUGRA. In this paper, we consider the SUGRA\string action at one loop

Claudio A. Scrucca, Marco Serone

We study in detail the pattern of anomaly cancellation in D=6 Type IIB Z_N orientifolds, occurring through a generalized Green-Schwarz mechanism involving several RR antisymmetric tensors and scalars fields. The starting point is a direct string theory computation of the inflow of anomaly arising from magnetic interaction of D-branes, O-planes and fixed-poin

HongSheng Zhao

We study the effect of reddening on microlensed stars towards the LMC. If lenses are in the LMC disk, then the source stars should be at the far side or behind the LMC disk. Thus they should experience more reddening and extinction by dust in the LMC disk than typical stars in the immediate neighbouring lines of sight. We simulate this effect in a variety of

John McDonald

It has been observed that a large lepton asymmetry, n_{L}/s \approx 0.1, can prevent the Higgs expectation value from going to zero at high temperature, resulting in the non-restoration of the SU(2)XU(1) gauge symmetry and other symmetries. This could allow for the elimination of domain walls and other dangerous topological defects. Here we show that if the

D. J. Singh, P. Blaha, K. Schwarz, I. I. Mazin

First principles density functional calculations of the electronic and magnetic properties of spinel-structure LiV$_{2}$O$_{4}$ have been performed using the full potential linearized augmented planewave method. The calculations show that the electronic structure near the Fermi energy consists of a manifold of 12 bands derived from V $t_{2g}$ states, weakly

R. D&#39;Hulst, G. J. Rodgers

We investigate the dynamics of the choice of an active strategy in the minority game. A history distribution is introduced as an analytical tool to study the asymmetry between the two choices offered to the agents. Its properties are studied numerically. It allows us to show that the departure from uniformity in the initial attribution of strategies to the a

R. Casalbuoni, S. De Curtis, D. Dominici, R. Gatto

We consider a minimal extension to higher dimensions of the Standard Model, having one compactified dimension, and we study its experimental tests in terms of electroweak data. We discuss tests from high-energy data at the $Z$-pole, and low-energy tests, notably from atomic parity violation data. This measurement combined with neutrino scattering data strong

Ricardo Troncoso, Jorge Zanelli

The most general theory of gravity in d-dimensions which leads to second order field equations for the metric has [(d-1)/2] free parameters. It is shown that requiring the theory to have the maximum possible number of degrees of freedom, fixes these parameters in terms of the gravitational and the cosmological constants. In odd dimensions, the Lagrangian is

Yasuo Umino, Vicente Vento

We extend the N-quantum approach to quantum field theory to finite temperature ($T$) and chemical potential ($μ$) and apply it to the NJL model. In this approach the Heisenberg fields are expressed using the Haag expansion while temperature and chemical potential are introduced simultaneously through a generalized Bogoliubov transformation. Known mean field

Sangmin Lee

We study the exchange diagrams in the computation of four-point functions of all chiral primary operators in D=4, $\mathcal{N}=4$ Super-Yang-Mills using AdS/CFT correspondence. We identify all supergravity fields that can be exchanged and compute the cubic couplings. As a byproduct, we also rederive the normalization of the quadratic action of the exchanged

W. Chen

The quasi-Newton equation is the very basis of a variety of the quasi-Newton methods. By using a relationship formula between nonlinear polynomial equations and the corresponding Jacobian matrix. presented recently by the present author, we established an exact alternative of the approximate quasi-Newton equation and consequently derived an modified BFGS upd

Sergei M. Kuzenko, Stefan Theisen

Using a manifestly supersymmetric formalism, we determine the general structure of two- and three- point functions of the supercurrent and the flavour current of N = 2 superconformal field theories. We also express them in terms of N = 1 superfields and compare to the generic N = 1 correlation functions. A general discussion of the N = 2 supercurrent superfi

J. H. Field, D. Sciarrino

A systematic study is made of the data dependence of the parameter $A_{\rm{b}}$, that, since 1995, has shown a deviation from the Standard Model prediction of between 2.4 and 3.1 standard deviations. Issues addressed include: the effect of particular measurements, values found by individual experiments, LEP/SLD comparison, and the treatment of systematic err

Michael Baake

Two results on palindromicity of bi-infinite words in a finite alphabet are presented. The first is a simple, but efficient criterion to exclude palindromicity of minimal sequences and applies, in particular, to the Rudin-Shapiro sequence. The second provides a constructive method to build palindromic minimal sequences based upon regular, generic model sets

Yu. B. Gaididei, S. F. Mingaleev, P. L. Christiansen

We consider a curved chain of nonlinear oscillators and show that the interplay of curvature and nonlinearity leads to a symmetry breaking when an asymmetric stationary state becomes energetically more favorable than a symmetric stationary state. We show that the energy of localized states decreases with increasing curvature, i.e. bending is a trap for nonli

R. Hofmann, T. Gutsche, Amand Faessler

From the hypothesis that at zero temperature the square root of the spectral continuum threshold $s_0$ is linearly related to the QCD scale $Λ$ we derive in the chiral limit and for temperatures considerably smaller than $Λ$ scaling relations for the vacuum parts of the Gibbs averaged scalar operators contributing to the thermal operator product expansion of

Guenther Goerz, Joerg Spilker, Volker Strom, Hans Weber

The paper describes the speech to speech translation system INTARC, developed during the first phase of the Verbmobil project. The general design goals of the INTARC system architecture were time synchronous processing as well as incrementality and interactivity as a means to achieve a higher degree of robustness and scalability. Interactivity means that in

Takeru Ken Suzuki, Yuzuru Yoshii, Toshitaka Kajino

A model of supernova-driven chemical evolution of the Galactic halo, recently proposed by Tsujimoto, Shigeyama, & Yoshii (1999, ApJL, 519, 64), is extended in order to investigate the evolution of light elements such as Be and B (BeB), which are produced mainly through spallative reactions with Galactic cosmic rays. In this model each supernova sweeps up the

Apoloniusz Tyszka

Let M be the ideal of first category subsets of R and non(M)=min{card X: X \subseteq R, X \not\in M}. We consider families Φof sequences converging to \infty, with the property that for every open set U \subseteq R that is unbounded above there exists a sequence belonging to Φ, which has an infinite number of terms belonging to U. We present assumptions abou

B. Carazza

This article examines the decoherence of a macroscopic body using a simple model of the environment and following the evolution of the pure state for the whole system. We found that decoherence occurs for very general initial conditions and were able to confirm a number of widely accepted features of the process.

Angelo Bassi, GianCarlo Ghirardi

In view of the arguments put forward by Clifton and Monton [1999] in a recent preprint, we reconsider the alleged conflict of dynamical reduction models with the enumeration principle. We prove that our original analysis of such a problem is correct, that the GRW model does not meet any difficulty and that the reasoning of the above authors is inappropriate

Milos V. Lokajicek

It has been shown that quantum paradoxes have followed from one special assumption, i.e., from attributing basic physical meaning to Hamiltonian eigenfunctions and representing all physical states by vectors of the Hilbert space spanned on these eigenfunctions. However, any paradoxical properties disappear if the physical states are represented by vectors fr

Dmitri A. Uzdensky, Russell M. Kulsrud

In this paper we present a two-dimensional numerical simulation of a reconnection current layer in incompressible resistive magnetohydrodynamics with uniform resistivity in the limit of very large Lundquist numbers. We use realistic boundary conditions derived consistently from the outside magnetic field, and we also take into account the effect of the backp

C. P. Viazminsky

In classical mechanics, a procedure for simultaneous synchronization in all inertial frames is consistent with the Galilean transformation. However, if one attempts to achieve such a synchronization utilizing light signals, he will be facing in the first place the break down of simultaneity, and secondly, a self-contradictory transformation that has the Lore

G. Quznetsov

The relativity theory principles and the quants theory principles are deduced from logic properties of the information, obtained from a physics device.

Gunn Quznetsov

The principal time properties - the one-dimensionality and the irreversibility -, the space metric properties and the spatial-temporal principles of the theory of the relativity are deduced from three natural logic properties of the information, obtained by a physics device. Hence, the transformations of the complete Poincare group are deduced from that.

D. Drechsel, S. S. Kamalov, G. Krein, B. Pasquini

Generalized nucleon polarizabilities for virtual photons can be defined in terms of electroproduction cross sections as function of the 4-momentum transfer $Q^2$. In particular, the sum of the generalized electric and magnetic polarizabilities $Σ=α+β$ and the spin polarizability $γ$ can be expressed by virtual photon absorption cross sections integrated over

M. S. Hussein, M. P. Pato

A multifractal analysis is performed on the universality classes of random matrices and the transition ones.Our results indicate that the eigenvector probability distribution is a linear sum of two chi-squared distribution throughout the transition between the universality ensembles of random matrix theory and Poisson .

P. Navratil, G. P. Kamuntavicius, B. R. Barrett

We present a translationally invariant formulation of the no-core shell model approach for few-nucleon systems. We discuss a general method of antisymmetrization of the harmonic-oscillator basis depending on Jacobi coordinates. The use of a translationally invariant basis allows us to employ larger model spaces than in traditional shell-model calculations. M

V. Pascalutsa, J. A. Tjon

Various quasipotential two-body scattering equations are studied at the one-loop level for the case of $t$- and $u$-channel exchange potentials. We find that the quasipotential equations devised to satisfy the one-body limit for the $t$-channel exchange potential can be in large disagreement with the field-theoretical prediction in the case of $u$-channel ex

E. Friedman, A. Gal

The strongly absorptive optical potentials $V_{\rm opt}$ which have been deduced from the strong-interaction level shifts and widths in X-ray spectra of $K^-$ and $\bar p$ atoms produce effective repulsion leading to substantial suppression of the {\it atomic} wave functions within the nucleus. The width of atomic levels then saturates as function of the str

I. Moerdijk

We give a universal construction of families of Hopf $P$-algebras for any Hopf operad $P$. As a special case, we recover the Connes-Kreimer Hopf algebra of rooted trees.

Ivan Smith

Integral symplectic 4-manifolds may be described in terms of Lefschetz fibrations. In this note we give a formula for the signature of any Lefschetz fibration in terms of the second cohomology of the moduli space of stable curves. As a consequence we see that the sphere in moduli space defined by any (not necessarily holomorphic) Lefschetz fibration has posi

Alex Kasman, Emma Previato

In one variable, there exists a satisfactory classification of commutative rings of differential operators. In several variables, even the simplest generalizations seem to be unknown and in this report we give examples and pose questions that may suggest a theory to be developed. In particular, we address the existence of a ``spectral variety&#39;&#39; gener

Alexandre Kabanov, Takashi Kimura

The Gromov-Witten invariants of a smooth, projective variety $V$, when twisted by the tautological classes on the moduli space of stable maps, give rise to a family of cohomological field theories and endow the base of the family with coordinates. We prove that the potential functions associated to the tautological $ψ$ classes (the large phase space) and the

Marc Lackenby

For the purposes of this paper, Dehn surgery along a curve K in a 3-manifold M with slope r is `exceptional&#39; if the resulting 3-manifold M_K(r) is reducible or a solid torus, or the core of the surgery solid torus has finite order in the fundamental group of M_K(r). We show that, providing the exterior of K is irreducible and atoroidal, and the distance

C. P. Viazminsky

We construct the field A generated by n algebraically independent elements, and show that the linear space of derivations over this field is faithfully represented by the linear space of the n-th fold Cartesian product of this field acting through inner product on the gradient of this field. We prove also that functional independence of a set in this field i

John McKay

These graphs generalize both affine and finite type and provide an explanation for some quantum properties of roots of unity.

S. A. Merkulov

This is a comment on the Kuranishi method of constructing analytic deformation spaces. It is based on a simple observation that the Kuranishi map can always be inverted in the category of $L_{\infty}$-algebras. The $L_{\infty}$-structure obtained by this inversion is used to define an &#39;&#39;unobstructed&#39;&#39; deformation functor which is always repre

Richard Dawid

We reconsider the options for cosmological holography. We suggest that a global and time--symmetric version of the Fischler-Susskind bound is the most natural generalization of the holographic bound encountered in AdS and De Sitter space. A consistent discussion of cosmological holography seems to imply an understanding of the notion of ``number of degrees o

Igor Bandos, Jerzy Lukierski, Christian Preitschopf, Dmitri Sorokin

We construct simple twistor-like actions describing superparticles propagating on a coset superspace OSp(1|4)/SO(1,3) (containing the D=4 anti-de-Sitter space as a bosonic subspace), on a supergroup manifold OSp(1|4) and, generically, on OSp(1|2n). Making two different contractions of the superparticle model on the OSp(1|4) supermanifold we get massless supe

Pietro Menotti, Domenico Seminara

We develop the canonical ADM approach to 2+1 dimensional gravity in presence of point particles. The instantaneous York gauge can be applied for open universes or universes with the topology of the sphere. The sequence of canonical ADM equations is solved in terms of the conformal factor. A simple derivation is given for the solution of the two body problem.

Giovanni Amelino-Camelia, Shahn Majid

Quantum group Fourier transform methods are applied to the study of processes on noncommutative Minkowski spacetime $[x^i,t]=\imathλx^i$. A natural wave equation is derived and the associated phenomena of {\it in vacuo} dispersion are discussed. Assuming the deformation scale $λ$ is of the order of the Planck length one finds that the dispersion effects are

A. Ilakovac, M. Kolanovic, S. Pallua, P. Prester

In this paper we investigate complex solutions of the Bethe equations in the two-particle sector both for arbitrary finite number of sites and for the thermodynamic limit . We find the number of complex solutions (strings) and compare it with the string conjecture prediction. Some simple properties of these solutions like position in the spectrum, crossing o

A. Ilakovac, M. Kolanovic, S. Pallua, P. Prester

In this paper we count the numbers of real and complex solutions to Bethe constraints in the two particle sector of the XXZ model. We find exact number of exceptions to the string conjecture and total number of solutions which is required for completeness.

S. P. Khastgir, R. Sasaki, K. Takasaki

Calogero-Moser models and Toda models are well-known integrable multi-particle dynamical systems based on root systems associated with Lie algebras. The relation between these two types of integrable models is investigated at the levels of the Hamiltonians and the Lax pairs. The Lax pairs of Calogero-Moser models are specified by the representations of the r