February 1996 arXiv papers — page 2

F. Bonetto, G. Gallavotti

We describe a way of interpreting the chaotic principle of (ref. [GC1]) more extensively than it was meant in the original works. Mathematically the analysis is based on the dynamical notions of Axiom A and Axiom B and on the notion of Axiom C, that we introduce arguing that it is suggested by the results of an experiment (ref. [BGG]) on chaotic motions. Phy

Neta A. Bahcall, Siang Peng Oh

The peculiar velocity function of clusters of galaxies is determined using an accurate sample of cluster velocities based on Tully-Fisher distances of Sc galaxies (Giovanelli et al 1995b). In contrast with previous results based on samples with considerably larger velocity uncertainties, the observed velocity function does not exhibit a tail of high velocity

Jose L. Sanz, Enrique Martinez-Gonzalez, Laura Cayon, Joseph Silk

A second--order perturbation theory approach is developed to calculate temperature anisotropies in the cosmic microwave background. Results are given for open universes and fluctuations corresponding to CDM models with either Harrison-Zeldovich (HZ) or Lyth-Stewart-Ratra-Peebles (LSRP) primordial energy--density fluctuation power spectrum. Our perturbation t

Rosendo Vilchez-Gomez, Roser Pello, Blai Sanahuja

We study the photometric properties and content of the distant clusters of galaxies Cl 1613+3104 (z = 0.415) and Cl 1600+4109 (z = 0.540). The former is a rich, concentrated cluster which shows a strong evidence for segregation in luminosity and color. Its population of galaxies separates into two different kinds of objects: a red population compatible with

Colin A. Norman, Andrea Ferrara

We discuss the likely sources of turbulence in the ISM and explicitly calculate the detailed grand source function for the conventional sources of turbulence from supernovae, superbubbles, stellar winds and HII regions. We find that the turbulent pumping due to the grand source function is broad band, consequently expanding the inertial range of the cascade.

Mitchell Rothstein

The Fourier-Mukai transform is lifted to the derived category of sheaves with connection on abelian varieties. The case of flat connections (D-modules) is discussed in detail.

Chikashi Miyazaki, Wolfgang Vogel

The aim of this paper is to start a systematic investigation of the arithmetic degree of projective schemes as introduced by D. Bayer and D. Mumford. One main theme concerns itself with the behaviour of this arithmetic degree under hypersurface sections. The notion of arithmetic degree involves the new concept of length-multiplicity of embedded primary ideal

Chikashi Miyazaki, Wolfgang Vogel

The Castelnuovo-Mumford regularity reg(X) of a projective scheme X was introduced by Mumford by generalizing ideas of Castelnuovo. The interest in this concept stems partly from the fact that X is m-regular if and only if for every p \geq 0 the minimal generators of the p-th syzygy module of the defining ideal I of X occur in degree \leq m + p. There are som

Mark Green

It is proved, as was conjectured by Eisenbud-Koh-Stillman, that for a finitely generated graded module $M$ over the symmetric algebra $S(V)$, if the Koszul group ${\cal K}_{p,0}(M,V)\ne 0$, then the set of rank 1 relations in $M_0\otimes V$ has dimension $\ge p$. The method is by using ``exterior minors" to study syzygies of an ideal derived from the Kos

Alexander Kusenko, Paul Langacker, Gino Segre

The scalar potential of the MSSM may have local and global minima characterized by non-zero expectation values of charged and colored bosons. Even if the true vacuum is not color and charge conserving, the early Universe is likely to occupy the minimum of the potential in which only the neutral Higgs fields have non-zero vev's. The stability of this fals

T. R. Kirkpatrick, D. Belitz

Long-ranged, or power-law, behavior of correlation functions in both space and time is discussed for classical systems and for quantum systems at finite temperature, and is compared with the corresponding behavior in quantum systems at zero temperature. The origin of the long-ranged correlations is explained in terms of soft modes. In general, correlations a

F. Prada, C. Gutierrez, R. F. Peletier, C. D. McKeith

We have found that the bulge of the large, nearby Sb galaxy NGC 7331 rotates retrograde to its disk. Analysis of spectra in the region of the near-IR Ca II triplet along the major axis shows that, in the radial range between 5'' and ~20'', the line of sight velocity distribution of the absorption lines has two distinct peaks, and can be decom

T. P. Devereaux, A. Virosztek, A. Zawadowski

A theory of electronic Raman scattering in the presence of several energy bands crossing the Fermi surface is developed. The contributions to the light scattering cross section are calculated for each band and it is shown that the cross section can be written in terms of the sum of the single band contributions and a mixing term which only contributes to the

Thomas Mehen

We compute the $O(β_0 α_s^2)$ QCD corrections to the Standard Model decay $t\rightarrow W^+ b$ as well as the non standard decay $t\rightarrow H^+ b$. We then use our results to compute the BLM scale for these decays, and study the dependence of the BLM scale on the mass of the boson in the decay. We find that the BLM procedure gives extremely small scales w

Ken Ganga, Bharat Ratra, Josh Gundersen, Naoshi Sugiyama

We develop methods to account for experimental and observational uncertainties in likelihood analyses of data from cosmic microwave background (CMB) anisotropy experiments and apply them to an analysis of the UCSB South Pole 1994 (SP94) experiment. Observationally motivated open and spatially-flat $Λ$, cold dark matter cosmogonies are considered. Among the m

Alexander Altland, Martin R. Zirnbauer

Normal-conducting mesoscopic systems in contact with a superconductor are classified by the symmetry operations of time reversal and rotation of the electron's spin. Four symmetry classes are identified, which correspond to Cartan's symmetric spaces of type C, CI, D, and DIII. A detailed study is made of the systems where the phase shift due to Andre

Marco D'Attanasio, Tim R. Morris

If the Wilsonian renormalization group (RG) is formulated with a cutoff that breaks gauge invariance, then gauge invariance may be recovered only once the cutoff is removed and only once a set of effective Ward identities is imposed. We show that an effective Quantum Action Principle can be formulated in perturbation theory which enables the effective Ward i

Mans Henningson, Gregory Moore

We consider the type IIA string compactified on the Calabi-Yau space given by a degree 12 hypersurface in the weighted projective space ${\bf P}^4_{(1, 1, 2,2, 6)}$. We express the prepotential of the low-energy effective supergravity theory in terms of a set of functions that transform covariantly under $PSL(2, \mathbb{Z})$ modular transformations. These fu

D. Pfenniger, L. Martinet, F. Combes

Today we have numerous evidences that spirals evolve dynamically through various secular or episodic processes, such as bar formation and destruction, bulge growth and mergers, sometimes over much shorter periods than the standard galaxy age of 10-15 Gyr. This, coupled to the known properties of the Hubble sequence, leads to a unique sense of evolution: from

S. A. Pernice

A fully relativistic quark model is constructed and applied to the study of wave-functions as well as the spectrum of heavy-light mesons. The free parameters of the model are a constituent quark mass and (on the lattice) an adjustable r-parameter in the fermionic kinetic energy, while the confinement is introduced via potentials measured by MonteCarlo. The r

S. Rajeev A. Stern, P. Vitale

We consider the 2--dimensional Wess--Zumino--Witten (WZW) model in the canonical formalism introduced in a previous paper by two of us. Using an $r$--$s$ matrix approach to non--ultralocal field theories we find the Poisson algebra of monodromy matrices and of conserved quantities with a new, non--dynamical, $r$ matrix.

K. Pomorski, J. Bartel, J. Richert, K. Dietrich

The dependence of the transmission coefficient on the deformation, the collective rotation and excitation energy of the compound nucleus emitting light particles is introduced in the framework of Weißkopf's evaporation theory. The competition between fission and particle evaporation is treated by a~Langevin equation for the fission variable coupled to th

R. C. Rashkov, M. Stanishkov

In this letter we propose exact three-point correlation functions for N=1 supersymmetric Liouville theory. Along the lines of Zamolodchikov and Zamolodchikov paper (hep-th/9506136) we propose a generalized special function which describe the three-point amplitudes. We consider briefly the so called reflection amplitudes in the supersymmetric case.

Gary Wegner, Matthew Colless, Glenn Baggley, Roger L. Davies

The EFAR project is a study of 736 candidate elliptical galaxies in 84 clusters lying in two regions towards Hercules-Corona Borealis and Perseus-Pisces-Cetus at distances cz = 6000-15000 km/s. In this paper (the first of a series) we present an introduction to the EFAR project and describe in detail the selection of the clusters and galaxies in our sample.

Eanna Flanagan, Robert Wald

The expected stress-energy tensor <T_{ab}> of quantum fields generically violates the local positive energy conditions of general relativity. However, <T_{ab}> may satisfy some nonlocal conditions such as the averaged null energy condition (ANEC), which would rule out traversable wormholes. Although ANEC holds in Minkowski spacetime, it can be violated in cu

Raymond Laflamme, Cesar Miquel, Juan Pablo Paz, Wojciech Hubert Zurek

We present a quantum error correction code which protects a qubit of information against general one qubit errors which maybe caused by the interaction with the environment. To accomplish this, we encode the original state by distributing quantum information over five qubits, the minimal number required for this task. We give a simple circuit which takes the

Isaac L. Chuang, Raymond Laflamme, Juan-Pablo Paz

We investigate the impact of loss (amplitude damping) and decoherence (phase damping) on the performance of a simple quantum computer which solves the one-bit Deutsch problem. The components of this machine are beamsplitters and nonlinear optical Kerr cells, but errors primarily originate from the latter. We develop models to describe the effect of these err

Kimio Ueno, Michitomo Nishizawa

We give an asymptotic expansion (the higher Stirling formula) and an infinite product representation (the Weierstrass product formula) of the Vignéras multiple gamma function by considering the classical limit of the multiple q-gamma function.

J. M. Udias, P. Sarriguren, E. Moya de Guerra, J. A. Caballero

The recent 208Pb(e,e&#39;p)207Tl data from NIKHEF-K at high missing momentum (p_m>300 MeV/c) are compared to theoretical results obtained with a fully relativistic formalism previously applied to analyze data on the low missing momentum (p_m < 300 MeV/c) region. The same relativistic optical potential and mean field wave functions are used in the two p_m-reg

Gilles Pisier

Let $\eps >0$. We prove that there exists an operator $T_\eps:\ell_2\to\ell_2$, such that for any polynomial $P$ we have $\|{P(T)}\| \leq(1+\eps)\|{P}\|_\infty$, but which is not similar to a contraction, {\it i.e.} there does not exist an invertible operator $S:\ \ell_2\to\ell_2$ such that $\|{S^{-1}T_\eps S}\|\leq 1$. This answers negatively a question att

J. Gamboa

In these lectures several aspects of anyon in one and two dimensions are considered from the path integral formalism. This paper is based in a set of four lectures given by the author in the &#34;V Latinoamerican Workshop of Particles and Fields, hel in Puebla, Mexico.

John M. Cornwall

$SU(N)$ Yang-Mills theory in three dimensions, with a Chern-Simons term of level $k$ (an integer) added, has two dimensionful coupling constants, $g^2 k$ and $g^2 N$; its possible phases depend on the size of $k$ relative to $N$. For $k \gg N$, this theory approaches topological Chern-Simons theory with no Yang-Mills term, and expectation values of multiple

Dimitra Karabali, V. P. Nair

An analysis of how the mass gap could arise in pure Yang-Mills theories in two spatial dimensions is given

Ramzi R. Khuri

Under the six-dimensional heterotic/type $IIA$ duality map, a solitonic membrane solution of heterotic string theory transforms into a singular solution of type $IIA$ theory, and should therefore be interpreted as a fundamental membrane in the latter theory. This finding pointed to a gap in the formulation of string theory that was subsequently filled by the

O. Moritsch, M. Schweda, T. Sommer

We discuss the algebraic renormalization of the Yang--Mills gauge field theory in the presence of translations. Due to the translations the algebra between Sorella&#39;s $\d$--operator, the exterior derivative and the BRST--operator closes. Therefore, we are able to derive an integrated parameter formula collecting in an elegant and compact way all nontrivia

D. M. Gitman, A. E. Gonçalves, I. V. Tyutin

We present here our considerations concerning the problem of classical consistency of pseudoclassical models touched upon in a recent comment on our paper &#34;New pseudoclassical model for Weyl particle&#34;.

Ken-ji Hamada

The Ward identities of the $W_{\infty}$ symmetry in 2D string theory in the tachyon background are studied in the continuum approach. Comparing the solutions with the matrix model results, it is verified that 2D string amplitudes are different from the matrix model amplitudes only by the external leg factors even in higher genus. This talk is based on the re

S. Hosono, B. H. Lian

We analyze GKZ(Gel&#39;fand, Kapranov and Zelevinski) hypergeometric systems and apply them to study the quantum cohomology rings of Calabi-Yau manifolds. We will relate properties of the local solutions near the large radius limit to the intersection rings of a toric variety and of a Calabi-Yau hypersurface. (Talk presented at &#34;Frontiers in Quantum Fiel

Bin Chen, Takesi Saito, Hong-Bo Teng, Kunihiko Uehara

We derive the $N=2$ and $4$ super Yang-Mills theories from the viewpoint of the $M_4\times Z_2\times Z_2$ gauge theory. Scalars and pseudoscalars appearing in the theories are regarded as gauge fields along the directions on $Z_2\times Z_2$ discrete space.

Alok Kumar, Koushik Ray

We present several Orientifolds of M-Theory on $K_3\times S^1$ by additional projections with respect to the finite abelian automorphism groups of $K_3$. The resulting models correspond to anomaly free theories in six dimensions. We construct explicit examples which can be interpreted as models with eight, four, two and one vector multiplets and $N=1$ supers

C. D. Fosco, T. Matsuyama

We study the canonical structure of the $SU(N)$ non-linear Sigma-model in a polynomial, first-order representation. The fundamental variables in this description are a non-Abelian vector field L_mu and a non-Abelian antisymmetric tensor field theta_{mu nu}, which constrains L_{mu} to be a `pure gauge&#39; (F_{mu nu}(L) = 0) field. The second-class constraint

C. D. Fosco, T. Matsuyama

We construct a perturbation theory for the SU(2) non-linear Sigma-model in 2+1 dimensions using a polynomial, first-order formulation, where the variables are a non-Abelian vector field L_mu (the left SU(2) current), and a non-Abelian pseudovector field $θ_μ$, which imposes the condition F_{mu nu}(L) = 0. The coordinates on the group do not appear in the Fey

M. Araki, Y. Tanii

The Ward-Takahashi identities in large N field theories are expressed in a simple form using master fields. Operators appearing in these expressions are found to be generators of symmetry transformations acting on the master fields.

H. Lu, C. N. Pope, K. S. Stelle

In this paper, we study the actions of the Weyl groups of the U duality groups for type IIA string theory toroidally compactified to all dimensions $D\ge 3$. We show how these Weyl groups implement permutations of the field strengths, and we discuss the Weyl group multiplets of all supersymmetric $p$-brane solitons.

S. P. Brumby, R. Foot, R. R. Volkas

The exact parity model (EPM) is a simple extension of the Standard Model which reinstates parity invariance as an unbroken symmetry of nature. The mirror matter sector of the model can interact with ordinary matter through gauge boson mixing, Higgs boson mixing and, if neutrinos are massive, through neutrino mixing. The last effect has experimental support t

V. Barger, M. S. Berger, J. F. Gunion, T. Han

Techniques and strategies for discovering and measuring the properties of Higgs bosons via $s$-channel production at a $μ^+μ^-$ collider, and the associated requirements for the machine and detector, are discussed in detail. The unique feature of $s$-channel production is that, with good energy resolution, the mass, total width and partial widths of a Higgs

H. Ichie, H. Monden, H. Suganuma, H. Toki

We study the QCD phase transition at finite temperature and discuss the hadron bubble formation in the dual Ginzburg-Landau theory, which is an effective theory of QCD and describes the color confinement via QCD-monopole condensation. We formulate the effective potential at various temperatures and find that thermal effects reduce the QCD-monopole condensate

H. Ichie, H. Suganuma, H. Toki

We study the system of multi color-flux-tubes in terms of the dual Ginzburg -Landau theory. We consider two ideal cases, where the directions of all the color-flux-tubes are the same in one case and alternative in the other case for neighboring flux-tubes. We formulate the system of multi color-flux -tubes by regarding it as the system of two color-flux-tube

Chao-Hsi Chang, Yu-Qi Chen, Robert J. Oakes

A comparative study of the full $α_s^4$ perturbative QCD calculation of the hadronic production of the $B_c$ and $B_c^*$ mesons and the fragmentation approximation is presented. We examined the various subprocesses in detail and the distribution $C(z)$, where $z$ is twice the fraction of the $B_c$ or $B_c^*$ meson energy in the center of mass of the subproce

Dima Bardin, Dietrich Lehner, Tord Riemann

We study Standard Model four-fermion production in e+ e- annihilation at LEP2 energies and above using a semi-analytical approach. We derive the complete QED initial state corrections (ISR) to the reactions e+e- -> ZZ -> $f_1\bar{f_1}f_2\bar{f_2}$ and e+e- -> W+W- -> ${\bar f}_1^u f_1^d f_2^u {\bar f}_2^d$ with $f_1\neq f_2$~and $f_i \neq e^\pm, ν_e$. As com

Alberto Giovannini, Sergio Lupia, Roberto Ugoccioni

The shoulder structure of charged particles multiplicity distributions (MD&#39;s) in full phase space in $e^+e^-$ annihilation at the $Z_0$ peak and the quasi-oscillatory behavior of the ratio of factorial cumulants over factorial moments, $H_q$, as a function of the order $q$, are quantitatively reproduced within a simple parametrization of the MD in terms

Alexander Bochkarev, Joseph Kapusta

The linear O($N$) sigma model undergoes a symmetry restoring phase transition at finite temperature. We show that the nonlinear O($N$) sigma model also undergoes a symmetry restoring phase transition; the critical temperatures are the same when the linear model is treated in mean field approximation and the nonlinear model is treated to leading plus subleadi

F. A. Berends, A. I. Davydychev, V. A. Smirnov

The behaviour of two-loop two-point diagrams at non-zero thresholds corresponding to two-particle cuts is analyzed. The masses involved in a cut and the external momentum are assumed to be small as compared to some of the other masses of the diagram. By employing general formulae of asymptotic expansions of Feynman diagrams in momenta and masses, we construc

S. Collins, U. M. Heller, J. Sloan, J. Shigemitsu

We present a lattice investigation, partially including the effects of dynamical quarks, of the heavy-light mesons using NRQCD for the heavy quark and the Wilson action for the light quark. We performed an extensive calculation of the spectrum employing a multi-state, multi-exponential fitting analysis which enabled us to extract the $2S{-}1S$ splitting as w

Khalil M. Bitar

We present data testing the existence of a parity-flavor breaking phase in simulations of QCD with two flavors of light Wilson fermions. This is done by explicit simulations on lattice sizes of $6^4$, $8^4$ and $10^4$ for a variety of values of $β$ and $κ$ as well as the coefficient, $h$, of an explicit breaking term included in the action. We find that at $

M. Caselle, K. Pinn

We consider the question of removing the ultraviolet cutoff in a 2D Quantum Field Theory with an interaction term which is non-renormalizable by power counting. This model arises as the first non-trivial correction beyond the Gaussian approximation of the so called Capillary Wave or Drumhead Model, and is rather important from a physical point of view since

S. Bianco

This paper gives an experimental overview of current status and open questions on charm lifetimes and semileptonic decays, the latter including new results presented by E687 and CLEO at this Conference.

Thibault Damour, Gilles Esposito-Farese

Some recently discovered nonperturbative strong-field effects in tensor-scalar theories of gravitation are interpreted as a scalar analog of ferromagnetism: &#34;spontaneous scalarization&#34;. This phenomenon leads to very significant deviations from general relativity in conditions involving strong gravitational fields, notably binary-pulsar experiments. C

Robert Geroch

Apparently, all partial differential equations that describe physical phenomena in space-time can be cast into a universal quasilinear, first-order form. In this paper, we do two things. First, we describe some broad features of systems of differential equations so formulated. Examples of such features include hyperbolicity of the equations, constraints and

Neil J. Cornish

The study of dynamics in general relativity has been hampered by a lack of coordinate independent measures of chaos. Here we present a variety of invariant measures for quantifying chaotic dynamics in relativity by exploiting the coordinate independence of fractal dimensions. We discuss how preferred choices of time naturally arise in chaotic systems and how

F. Schein, P. C. Aichelburg, W. Israel

We construct a static axisymmetric wormhole from the gravitational field of two Schwarzschild particles which are kept in equilibrium by strings (ropes) extending to infinity. The wormhole is obtained by matching two three-dimensional timelike surfaces surrounding each of the particles and thus spacetime becomes non-simply connected. Although the matching wi

R. Cosgrove

The relativistic free particle system in 1+1 dimensions is formulated as a ``bi-Hamiltonian system&#39;&#39;. One Hamiltonian generates ordinary time translations, and another generates (essentially) boosts. Any observer, accelerated or not, sees evolution as the continuous unfolding of a canonical transformation which may be described using the two Hamilton

Roman R. Zapatrin

Any discrete differential manifold $M$ (finite set endowed with an algebraic differential calculus) can be represented by appropriate polyhedron ${\cal P}(M)$. This representation demonstrates the adequacy of the calculus of discrete differential manifolds and links this approach with that based on finitary substitutes of continuous spaces introduced by R.D.

Mucio A. Continentino

We generalize the scaling theory of heavy fermions for the case the shift exponent describing the critical Neel line is different from the crossover exponent characterizing the coherence line. We obtain the properties of the non-Fermi liquid system at the critical point and in particular the electrical resistivity. We study violation of hyperscaling in the F

E. H. Hwang, Ben Yu-Kuang Hu, S. Das Sarma

We study leading-order many-body effects of longitudinal optical (LO) phonons on electronic properties of one-dimensional quantum wire systems. We calculate the quasiparticle properties of a weakly polar one dimensional electron gas in the presence of both electron-phonon and electron-electron interactions. The leading-order dynamical screening approximation

Yong Baek Kim, Patrick A. Lee

We calculate the specific heat of composite fermion system in the half-filled Landau level. Two different methods are used to examine validity of the quasiparticle approximation when the two-body interaction is given by $V(q) = V_0 / q^{2-η}$ ($1 \le η\le 2$). The singular part of the specific heat is calculated from the free energy of the gauge field, which

Konstantin K. Likharev, Alexander N. Korotkov

We have analyzed energy dissipation in a digital device (``Single-Electron Parametron&#39;&#39;) in which discrete degrees of freedom are used for presenting digital information. If the switching speed is not too high, the device may operate reversibly (adiabatically), and the energy dissipation ${\cal E}$ per bit may be much less than the thermal energy $k_

A. S. Alexandrov, V. V. Kabanov

We develop the nonadiabatic polaron theory of superconductivity of $M_{x}C_{60}$ taking into account the polaron band narrowing and realistic electron-phonon and Coulomb interactions. We argue that the crossover from the BCS weak-coupling superconductivity to the strong-coupling polaronic and bipolaronic superconductivity occurs at the BCS coupling constant

Tsutomu Momoi

We discuss conditions for the absence of spontaneous breakdown of continuous symmetries in quantum lattice systems at $T=0$. Our analysis is based on Pitaevskii and Stringari&#39;s idea that the uncertainty relation can be employed to show quantum fluctuations. For the one-dimensional systems, it is shown that the ground state is invariant under the continuo

Jean Carletta

Currently, computational linguists and cognitive scientists working in the area of discourse and dialogue argue that their subjective judgments are reliable using several different statistics, none of which are easily interpretable or comparable to each other. Meanwhile, researchers in content analysis have already experienced the same difficulties and come

Alexander Matro, David L. Freeman, Robert Q. Topper

The thermodynamic and structural properties of (NH$_4$Cl)$_n$ clusters, n=3-10 are studied. Using the method of simulated annealing, the geometries of several isomers for each cluster size are examined. Jump-walking Monte Carlo simulations are then used to compute the constant-volume heat capacity for each cluster size over a wide temperature range. To carry

J. J. Hope, C. M. Savage

This paper examines the feasibility of constructing an experiment which detects the atomic stimulation of a photon emission process. A beam of atoms (bosons) in an excited state is passed over an atomic trap which traps the atoms when they are in their internal ground state. When the trap contains a Bose-Einstein condensate, the cross-section for absorption

F. Combes, D. Pfenniger

We have recently proposed a new candidate for baryonic dark matter: very cold molecular gas, in near-isothermal equilibrium with the cosmic background radiation at 2.73 K. The cold gas, of quasi-primordial abundances, is condensed in a fractal structure, resembling the hierarchical structure of the detected interstellar medium. We present some perspectives o

D. Pfenniger

The ubiquitous clumpy state of the ISM raises a fundamental and open problem of physics, which is the correct statistical treatment of systems dominated by long range interactions. A simple solvable hierarchical model is presented which explains why systems dominated by gravity prefer to adopt a fractal dimension around 2 or less, like the cold ISM and large

Walter Simmons, John Learned, Sandip Pakvasa, Xerxes Tata

After a brief discussion of a possible relationship between the electroweak phase transition in highly compressed matter and gravitational collapse, we examine the speculative possibility that the electroweak phase transition might be contemporarily occurring in processes in neutron stars. We conjecture that adiabatic compression of neutron star matter due t

Hans Böhringer, Doris M. Neumann, Sabine Schindler, Renee C. Kraan-Korteweg

The cluster A3627 was recently recognized to be a very massive, nearby cluster in a galaxy survey close to the galactic plane. We are reporting on ROSAT PSPC observations of this object which confirm that the cluster is indeed very massive. The X-ray emission detected from the cluster extends over almost 1 degree in radius. The X-ray image is not spherically

N. Mowlavi, A. Jorissen, M. Arnould

The 19F production during the first dozen thermal pulses of AGB stars with (M=3,Z=0.02), (M=6,Z=0.02) and (M=3,Z=0.001) is investigated on grounds of detailed stellar models and of revised rates for 15N(a,g)19F and 18O(a,g)22Ne. These calculations confirm an early expectation that 19F {\it is} produced in AGB thermal pulses. They also enlarge substantially t

P. Pragacz, J. Ratajski

Let V be a vector bundle on a scheme X endowed with a nondegenerate symplectic or orthogonal form. Let G be a Grassmannian bundle parametrizing maximal isotropic subbundles of V. The main goal of the paper is to give formulas for the classes of the loci in G parametrizing those subbundles which intersect successive members of of a fixed flag of isotropic sub

Klaus Altmann

P-resolutions of two-dimensional, cyclic quotient singularities have been introduced to study deformation theory. Those P-resolutions (as well as the singularities themselves) are toric varieties. In the present paper we give a straight, elementary description of them just by their defining fans.

S. Oxx, D. P. Choudhury, Balam A. Willemsen, H. Srikanth

Measurements of the rf penetration depth λ(T,H,θ) are used to study the superconducting order parameter, vortex dynamics in the mixed state and delineate critical fields in the borocarbide superconductor YNi_2B_2C. The lower critical field has an anomalous T dependence, H_{c1}(T)=1.12[1-(T/T_c)] kOe, which is however consistent with independent superfluid de

Emilio Torrente-Lujan

We investigate the effects of random density fluctuations on neutrino oscillations in the Sun environment. We show how the average of certain quantities which can be used to describe the MSW effect can be computed analytically. We examine also the hypothesis commonly accepted that only perturbations inside the resonance layer can have relevance. The average

Seok Jae Park, Ethan T. Vishniac

We consider the radial buoyancy of vertical magnetic field lines in radiation and gas pressure dominated accretion disks. We find that in addition to radial drift driven by turbulent diffusion and biased by the global field geometry, there are buoyancy effects which tend to move magnetic flux outward. In gas pressure dominated disks the poloidal magnetic fie

Francesco Vissani

We review various features of the $R$-parity breaking phenomenology, with particular attention to the low energy observables, and to the patterns of the $R$-parity breaking interactions that arise in Grand Unified models.

S. M. Troshin, N. E. Tyurin

We consider mechanism for hyperon polarization in inclusive production. The main role belongs to the orbital angular momentum and polarization of the strange quark-antiquark pairs in the internal structure of the constituent quarks. We consider a nucleon as a core consisting of the constituent quarks embedded into quark condensate. The nonperturbative hadron

O. Yu. Shvedov

The model consisting of gravitational, scalar and axionic fields is considered. It is shown that the action of the Lavrelashvili-Rubakov-Tinyakov wormhole can be made arbitrarily negative by varying the parameters of the model. This means that semiclassically calculated probability of transition through this wormhole is not exponentially small (as usual) but

T. Miyazaki, D. Yoshioka

An antiferromagnetic Heisenberg model on a 1/5-depleted two-dimensional square-lattice, a model of CaV$_4$O$_9$, is investigated by variational Monte Carlo simulation. A prototype of a trial wave function is made by projecting out the doubly occupied states from the Schwinger-boson mean-field solution. Then variational Monte Carlo simulation is performed up

R. Jimenez, P. Thejll, U. Jorgensen, J. MacDonald

We have applied a new method to analyze the horizontal branch (HB) morphology in relation to the distribution of stars near the red giant branch (RGB) tip for the globular clusters M22, M5, M68, M107, M72, M92, M3 and 47 Tuc. This new method permits determination of the cluster ages to greater accuracy than conventional isochrone fitting. Using the method in

M. I. Salkola, A. V. Balatsky, D. J. Scalapino

Scanning tunneling microscopy can provide a probe for the detailed study of quasiparticle states in high-Tc superconductors. We propose that it can also be used to acquire specific information about impurity-induced quasiparticle states and the superconducting order-parameter structure. In particular, the local density of states is found to be sensitive to i

Sergio Ferrara, Renata Kallosh

We find a general principle which allows one to compute the area of the horizon of N=2 extremal black holes as an extremum of the central charge. One considers the ADM mass equal to the central charge as a function of electric and magnetic charges and moduli and extremizes this function in the moduli space (a minimum corresponds to a fixed point of attractio

Abhijit Bhattacharyya, Sanjay K. Ghosh, S. C. Phatak, Sibaji Raha

The temperature dependence of the $ϕ$ meson mass and its decay width ($ϕ\rightarrow K \bar{K}$)have been studied from an effective non-linear chiral Lagrangian in $SU(3)$. Effective mass has been obtained from the pole position of the full propagator. The width has also been calculated. It has been found that the mass decreases with temperature very slowly w

A. Atalmi, M. Baldo, G. F. Burgio, A. Rapisarda

We discuss the presence of both dynamical chaos and signals of a second--order phase transition in numerical Vlasov simulations of nuclear multifragmentation. We find that chaoticity and criticality are strongly related and play a crucial role in the process of fragments formation. This connection is not limited to our model and seems a rather general featur

W. Melnitchouk, A. W. Thomas

We re-examine the large-x neutron/proton structure function ratio extracted from the latest deuteron data, taking into account the most recent developments in the treatment of Fermi motion, binding and nucleon off-shell effects in the deuteron. Our findings suggest that as x->1 the ratio of the neutron to proton structure functions (F_2^n/F_2^p) is consisten

Armen Edigarian

We prove that the pluricomplex Green function has the product property $g_{D_1\times D_2}=\max\{ g_{D_1},g_{D_2}\}$ for any domains $D_1\subset\Bbb C^n$ and $D_2\subset\Bbb C^m$.

Jens Hoppe

A multilinear M-dimensional generalization of Lax pairs is introduced and its explicit form is given for the recently discovered class of time-harmonic, integrable, hypersurface motions.

M. M. Islam, S. J. Puglia

By generalizing the Fujikawa approach, we show in the path-integral formalism: (1) how the infinitesimal variation of the fermion measure can be integrated to obtain the full anomalous chiral action; (2) how the action derived in this way can be identified as the Chern-Simons term in five dimensions, if the anomaly is consistent; (3) how the regularization c

Kostas Philippides, Alberto Sirlin

A simple and testable necessary condition for the gauge independence of the Pinch Technique self-energies at two loops is discussed. It is then shown that, in the case of the $Z$ and $W$ self-energies, the condition is indeed satisfied by the Papavassiliou-Pilaftsis formulation.

P. Gondolo, L. Bergstrom

We analyze the direct detection rate of minimal supersymmetric neutralino dark matter in germanium, sapphire and sodium iodide detectors, imposing cosmological and accelerator bounds including those from \bsg\ decay. In contrast with several other recent analyses we find models with light charged higgsinos and large stop mixing in which the counting rate in

P. Gondolo, G. Ingelman, M. Thunman

We have updated our previous investigation of the production of muons and neutrinos in cosmic ray interactions with the atmosphere, taking account of recent results from the $ep$ collider HERA in our QCD-based model for hadronic interactions. Qualitatively, our previous results remain unmodified: our predictions for the conventional muon and neutrino fluxes

F. Cornet

An introduction to the methods and ideas of Chiral Perturbation Theory is presented in this talk. The discussion is illustrated with some phenomenological predictions that can be compared with available experimental results.

Sangyong Jeon, Joseph Kapusta

We calculate the pion decay constant near the critical temperature of the $O(N)$ nonlinear sigma model in the large $N$ limit. Making use of the known low temperature behavior, we construct a Padé approximant to obtain the behavior of $f_π(T)$ at all temperatures.