August 1994 arXiv papers — page 4

J. Kisker H. Rieger, M. Schreckenberg

The non-equilibrium dynamics of a one-dimensional Ising model with uniform, short-ranged three-spin interactions is investigated. It is shown that this model possesses an exponentially large number of metastable configurations that are stable against single spin flips. This glass-like situation results in a complete freezing of the system at low temperatures

Mehran Kardar, Deniz Ertas

These notes are for the proceedings of the NATO Advanced Study Insitutue on "Scale Invariance, Interfaces, and Non--Equilibrium Dynamics", held at the Isaac Newton Institute, 20--30 June 1994. The four lectures address a number of issues related to dynamic fluctuations of lines in non-equilibrium circumstances. The first two are devoted to the critic

R. Eder, Y. Ohta

We present a new method for studying the low energy excitations in finite cluster systems and apply it to clarify the nature of the low energy spin excitations in the moderately doped t-J model. We find that the character of the low energy spin excitations changes within the Brillouin zone, with the dominant excitation for momentum transfer (pi,pi) being a s

Akira Inomata, Georg Junker

{}From Feynman's path integral, we derive quasi-classical quantization rules in supersymmetric quantum mechanics (SUSY-QM). First, we derive a SUSY counterpart of Gutzwiller's formula, from which we obtain the quantization rule of Comtet, Bandrauk and Campbell when SUSY is good. When SUSY is broken, we arrive at a new quantization formula, which is f

F. Seno, J. M. Yeomans

An expansion in inverse spin anisotropy, which enables us to study the behaviour of discrete spin models as the spins soften, is developed. In particular we focus on models, such as the chiral clock model and the $p$-state clock model with competing first and second neighbour interactions, where there are special multiphase points at zero temperature at whic

Joerg P. Ueberla

In this paper, we investigate the use of selectional restriction -- the constraints a predicate imposes on its arguments -- in a language model for speech recognition. We use an un-tagged corpus, followed by a public domain tagger and a very simple finite state machine to obtain verb-object pairs from unrestricted English text. We then measure the impact the

L. Infante

Faint star number counts in the photographic \jmag band and \bvcol colour distributions are presented for a 1.08 deg$^2$ field near the North Galactic Pole. Due to the excellent star/galaxy discrimination we count stars as faint as \jmag = 23. We compare the number counts and colour distributions in 5 adjacent fields near SA57. The number counts and colour d

L. Infante, P Fouque, G. Hertling, M. J. Way

We present magnitudes and redshifts of galaxies in the cluster of galaxies CL0017-20 and in the double cluster CL0500-24. Luminosity functions and velocity distributions have been derived. CL0017-20 possesses a virial mass of $2.9 \times 10^{14}$ M$_\odot$ and a \vmag band luminosity of $2.3 \pm 0.5 \times 10^{12}$ L$_\odot$ ($M/L_{\rm V} = 127$), much of it

L. Infante, C. J. Pritchet

The two-point angular correlation function of galaxies, \wte, has been computed from a new survey of faint galaxies covering a 2 deg$^2$ area near the North Galactic Pole. This survey, which is complete to limiting magnitudes \jmag=24 and \fmag=23, samples angular scales as large as $1\degpoint5$. Faint galaxies are found to be more weakly clustered (by a fa

A. Kogut, A. J. Banday, C. L. Bennett, G. Hinshaw

We use the two-point correlation function of the extrema points (peaks and valleys) in the COBE Differential Microwave Radiometers (DMR) 2-year sky maps as a test for non-Gaussian temperature distribution in the cosmic microwave background anisotropy. A maximum likelihood analysis compares the DMR data to n=1 toy models whose random-phase spherical harmonic

A. O. Barut, J. R. Zeni, A. J. Laufer

We present a general method to obtain a closed, finite formula for the exponential map from the Lie algebra to the Lie group, for the defining representation of the orthogonal groups. Our method is based on the Hamilton-Cayley theorem and some special properties of the generators of the orthogonal group, and is also independent of the metric. We present an e

Toshiaki Kaneko

A computer program has been developed which generates Feynman graphs automatically for scattering and decay processes in non-Abelian gauge theory of high-energy physics. A new acceleration method is presented for both generating and eliminating graphs. This method has been shown to work quite efficiently for any order of coupling constants in any kind of the

D. F. Wang, C. Gruber

Revised version, a few typing errors that might cause confusion of physics argument in the article have been corrected.

Andreas Albrecht

To what extent can our limited set of observations be used to pin down the specifics of a ``Theory of Everything''? In the limit where the links are arbitrarily tenuous, a ``Theory of Everything'' might become a ``Theory of Anything''. A clear understanding of what we can and can not expect to learn about the universe is particularly important in the field o

J. Piekarewicz, J. R. Shepard

We formulate $K^+$-nucleus quasielastic scattering in a manner which closely parallels standard treatments of $e^-$-nucleus quasielastic scattering. For $K^+$ scattering, new responses involving scalar contributions appear in addition to the Coulomb (or longitudinal) and transverse $(e,e')$ responses which are of vector character. We compute these respon

E. Heinz, H. M"uther, H. A. Mavromatis

A generalized RPA formalism is presented which treats pp and ph correlations on an equal footing. The effect of these correlations on the single-particle Green function is discussed and it is demonstrated that a self-consistent treatment of the single-particle Green function is required to obtain stable solutions. A simple approximation scheme is presented w

Edward Frenkel

Invited lecture at the International Congress of Mathematicians, Zuerich, August 3-11, 1994 (extended version), reviews free field realizations of affine Kac-Moody and W-algebras and their applications.

A. Ashtekar, J. Lewandowski, D. Marolf, J. Mourao

In gauge theories, physical histories are represented by space-time connections modulo gauge transformations. The space of histories is thus intrinsically non-linear. The standard framework of constructive quantum field theory has to be extended to face these {\it kinematical} non-linearities squarely. We first present a pedagogical account of this problem a

Yuri Bespalov

This is the second part of the paper. Results of the first part about crossed modules are applied here to study of quantum groups in braided categories. Correct cross product in the class of quantum braided groups is built. Criterion when quantum braided group is cross product is otained.

H. Aratyn, J. F. Gomes, A. H. Zimerman

We present an affine $sl (n+1)$ algebraic construction of the basic constrained KP hierarchy. This hierarchy is analyzed using two approaches, namely linear matrix eigenvalue problem on hermitian symmetric space and constrained KP Lax formulation and we show that these approaches are equivalent. The model is recognized to be the generalized non-linear Schröd

Giovanni Modanese

We give a general expression for the static potential energy of the gravitational interaction of two massive particles, in terms of an invariant vacuum expectation value of the quantized gravitational field. This formula holds for functional integral formulations of euclidean quantum gravity, regularized to avoid conformal instability. It could be regarded a

Yuri Bespalov

Let $H$ be a Hopf algebra in braided category $\cal C$. Crossed modules over $H$ are objects with both module and comodule structures satisfying some comatibility condition. Category ${\cal C}^H_H$ of crossed modules is braided and is concrete realization of general categorical construction. For quantum braided group $(H,{\cal R})$ corresponding braided cate

Marco Aurelio Diaz

Using the new CLEO bound on the branching ratio of the decay mode $b\longrightarrow sγ$ given by $1\times10^{-4}< B(b\longrightarrow sγ)<4\times10^{-4}$ at 95\% c.l., and the experimental bounds on the masses of the lightest chargino, the second lightest neutralino, and the light CP-odd Higgs, we find that a light gluino is incompatible with a class of super

Marco Aurelio Diaz

The renormalization of a system of coupled scalars fields is analyzed. By introducing a momentum dependent mixing angle we diagonalize the inverse propagator matrix at any momentum $p^2$. The zeros of the inverse propagator matrix, \ie, the physical masses, are then calculated keeping the full momentum dependence of the self energies. The relation between th

Marco A. Diaz, Tonnis A. ter Veldhuis, Thomas J. Weiler

In the Minimal Supersymmetric Model (MSSM) and the Next to Minimal Supersymmetric Model [(M+1)SSM], an upper bound on the lightest higgs mass can be calculated. On the other hand, vacuum stability implies a lower limit on the mass of the higgs boson in the Standard Model (SM). We find that a gap exists for $m_t \stackrel{>}{\sim} 165$ GeV between the SM and

Barbara Badelek, Jan Kwiecinski

We summarise existing experimental and theoretical knowledge on the structure function $F_2$ in the region of low $Q^2$ and low $x$. The constraints on the behaviour of structure functions in the limit $Q^2=0$ are listed. Phenomenological low $Q^2$ parametrisations of the $F_2$ are collected and their dynamical content is discussed. The high energy photoprod

Xiangdong Ji, Peter Unrau

We explore the physics of the parton-hadron duality in the nucleon structure functions appearing in lepton-nucleon scattering. We stress that the duality allows one to extract the higher-twist matrix elements from data in the resonance region, and learn about the properties of resonances if these matrix elements are known. As an example, we construct the mom

T. Arens, U. D. J. Gieseler, L. M. Sehgal

We study the energy correlation of charged leptons produced in the decay of a heavy Higgs particle $H\to t\bar t\to bl^+ν_l\bar bl^-\barν_l$ and $H\to W^+W^-\to l^+ν_ll^-\barν_l.$ The possible influence of $CP$--violation in the $Ht\bar t$ and $HW^+W^-$ vertices on the energy spectrum of the secondary leptons is analyzed. The energy distribution of the charg

Valerie Ben-Hamo, Yosef Nir

The smallness of the quark and lepton parameters and the hierarchy between them could be the result of selection rules due to a horizontal symmetry broken by a small parameter. The same selection rules apply to baryon number violating terms. Consequently, the problem of baryon number violation in Supersymmetry may be solved naturally, without invoking any es

Masako Bando, Izawa Ken-Iti, Tomohiko Takahashi

We continue to investigate the minimal SO(10)xU(1)_H model which we proposed recently. Renormalization group analysis of the model results in natural predictions of quark-lepton masses and Kobayashi-Maskawa matrix along with neutrino mixings adequate for solar neutrino oscillation.

Ralf Hempfling, Bernd A. Kniehl

We present the full one-loop correction to the relation between the running MSbar Yukawa coupling, $\overline h_f(μ)$, at some renormalization scale, $μ$, and the pole mass, $m_f$, of a fermion, $f$, in the standard model. Our result complements previous analyses that included just the QCD correction to this relation in the case of quarks. This allows us to

I. M. Dremin

Recent results in QCD on multiplicity distributions are briefly reviewed. QCD is able to predict very tiny features of multiplicity distributions which demonstrate that the negative binomial distribution (and, more generally, any infinitely divisible distribution) is inappropriate for precise description of experimental data. New fits of high energy multipli

A. Hoferichter, V. K. Mitrjushkin, M. Müller-Preussker, T. Neuhaus

We study the phase structure and the chiral limit of $4d$ compact lattice QED with Wilson fermions (both dynamical and quenched). We use the standard Wilson gauge action and also a modified one suppressing lattice artifacts. Different techniques and observables to locate the chiral limit are discussed.

Pedro F. Gonzalez-Diaz

A gravitational scenario is proposed where the euclidean action is invariant under the isotropic and homogeneous version of the euclidean {\it U(1)} group of local transformations of the scale factor and scalar matter field, interpreting the the trace of the second fundamental form as the gauge field. The model allows spontaneous breakdown of some involved s

Pedro F. Gonzalez-Diaz

This paper studies the time-symmetry problem in quantum gravity. The issue depends critically on the choice of the quantum state and has been considered in this paper by restricting to the case of quantum wormholes. It is seen that pure states represented by a wave functional are time symmetric. However, a maximal analytic extension of the wormhole manifold

R. Heid, Ya. B. Bazaliy, V. Martisovitsi, D. L. Cox

We present a new Ginzburg-Landau theory for superconductivity in UPt$_3$, based upon a multicomponent order parameter transforming under an irreducible space group representation; the phase is staggered in real space. Our model can explain the $H-T-P$ phase diagram including the tetracritical point for all field directions. We motivate this unconventional su

Alberto Debernardi, Stefano Baroni, Elisa Molinari

The anharmonic contribution to phonon lifetime and its temperature dependence is calculated from first principle in C, Si and Ge using third-order density-functional perturbation theory. Good agreement with available experimental data is obtained. Different competing two-phonon decay channels are compared and correlated with the density of final states.

C. Gruber, D. F. Wang

We review some recent progresses in study of the 1D strongly correlated electron systems of long range hopping and exchange. The systems are completely integrable, with infinite number of constants of motions. The results of the physical properties, such as wavefunctions, the full excitation spectrum and the thermodynamics, are also reviewed.

M V Jaric, E S Sorensen

The first explicit realization of the conjecture that phason dynamics leads to self-diffusion in quasicrystals is presented for the icosahedral Ammann tilings. On short time scales, the transport is found to be subdiffusive with the exponent $β\approx0.57(1)$, while on long time scales it is consistent with normal diffusion that is up to an order of magnitud

Julio F. Navarro, Carlos S. Frenk, Simon D. M. White

We present simulations of the formation and evolution of galaxy clusters in the Cold Dark Matter cosmogony. Clusters with a wide range of mass were selected from previous N-body models, and were resimulated at higher resolution using a combined N-body/Smooth Particle Hydrodynamics code. The effects of radiative cooling on the gas are neglected. While many pr

Robert W. Nelson, Scott Tremaine

We investigate the dynamical interaction of galactic warps with the surrounding dark matter halo, using analytic perturbation theory. A precessing warp induces a density wake in the collisionless dark matter, which acts back on the original warp, transferring energy and angular momentum between the warp and halo (dynamical friction). In most cases dynamical

Julio F. Navarro, Carlos S. Frenk, Simon D. M. White

We study the formation of galaxies by using $N$-body/hydrodynamics simulations to investigate how baryons collect at the centre of dark matter halos. We treat the dark matter as a collisionless fluid and the baryons as an ideal gas. We include the effects of gravity, pressure gradients, hydrodynamical shocks, and radiative energy losses, but we neglect star

David H Lyth, Andrew R Liddle

The standard model of large scale structure is considered, in which the structure originates as a Gaussian adiabatic density perturbation with a nearly scale invariant spectrum. The basic theoretical tool of cosmological perturbation theory is described, as well as the possible origin of the density perturbation as a vacuum fluctuation during inflation. Then

Jeremy S. Heyl, Shaun Cole, Carlos S. Frenk, Julio F. Navarro

We predict the observable properties of the galaxy population in popular hierarchical models of galaxy formation. We employ a detailed semianalytic procedure which incorporates the formation and merging of dark matter halos, the shock heating and radiative cooling of gas, self-regulated star formation, the merging of galaxies within dark matter halos, and th

T. Schramm, R. Kayser

We introduce a new complex formalism to describe arclet fields in clusters of galaxies and derive the appropriate inversion techniques to find the related mass distribution of the lensing cluster. Applying the complex formalism to the statistics of lensed background sources shows that the mean of the axial ratios of locally lensed isotropically distributed e

K. M. Apfeldorf, C. R. Ordonez

We investigate the issue of coordinate redefinition invariance by carefully performing nonlinear transformations in the discretized quantum mechanical path integral. By resorting to hamiltonian path integral methods, we provide the first complete derivation of the extra terms (beyond the usual jacobian term) which arises in the action when a nonlinear transf

Atish Dabholkar

String propagation on a cone with deficit angle $2π(1- \frac{1}{N} ) $ is described by constructing a non-compact orbifold of a plane by a $Z_{N}$ subgroup of rotations. It is modular invariant and has tachyons in the twisted sectors that are localized to the tip of the cone. A possible connection with the quantum corrections to the black hole entropy is out

Bjorn Jensen

In this work we study a {\it gedanken} experiment constructed in order to test the cosmic censorship hypothesis and the second law of black hole thermo-dynamics. Matter with a negative gravitating energy is imagined added to a near extremal $U(1)$-charged static black hole in Einstein-Maxwell theory. The dynamics of a similar process is studied and the therm

Yas-Hiro Quano

On the basis of the Andrews--Bailey construction, we derive fermionic sum representations of Virasoro characters of non unitary minimal models ${\cal M}(k,kp+p-1)$ and ${\cal M}(k,kp+1)$. These expressions include certain expressions conjectured by the Stony Brook group as special cases.

E. Getzler, M. M. Kapranov

Modular operads are a special type of operad: in fact, they bear the same relationship to operads that graphs do to trees (i.e. simply connected graphs). One of the basic examples of a modular operad is the collection of Deligne-Mumford-Knudsen moduli spaces $\bar{M}_{g,n}$ of stable pointed algebraic curves; hence the word ``modular.&#39;&#39; In this paper

Hua Wu, D. W. L. Sprung, J. Martorell

We present computational approaches as alternatives to the recent microwave cavity experiment by S. Sridhar and A. Kudrolli (Phys. Rev. Lett. {\bf 72}, 2175 (1994)) on iso-spectral cavities built from triangles. A straightforward proof of iso-spectrality is given based on the mode matching method. Our results show that the experiment is accurate to 0.3% for

L. Wilets, R. D. Puff

The dynamics of an idealized, infinite, MIT-type flux tube is followed in time as the interior evolves from a pure gluon field to a $\overline q \ q$ plasma. We work in color U(1). $\overline q\ q$ pair formation is evaluated according to the Schwinger mechanism using the results of Brink and Pavel. The motion of the quarks toward the tube endcaps is calcula

E. Elizalde, S. D. Odintsov

We suggest to consider conformal factor dynamics as applying to composite boundstates, in frames of the $1/N$ expansion. In this way, a new model of effective theory for quantum gravity is obtained. The renormalization group (RG) analysis of this model provides a framework to solve the cosmological constant problem, since the value of this constant turns out

N. Seiberg, E. Witten

We study four dimensional $N=2$ supersymmetric gauge theories with matter multiplets. For all such models for which the gauge group is $SU(2)$, we derive the exact metric on the moduli space of quantum vacua and the exact spectrum of the stable massive states. A number of new physical phenomena occur, such as chiral symmetry breaking that is driven by the co

A. Yu. Alekseev, H. Grosse, V. Schomerus

This paper further develops the combinatorial approach to quantization of the Hamiltonian Chern Simons theory advertised in \cite{AGS}. Using the theory of quantum Wilson lines, we show how the Verlinde algebra appears within the context of quantum group gauge theory. This allows to discuss flatness of quantum connections so that we can give a mathe- matical

Shogo Tanimura

It is known that there exist an infinite number of inequivalent quantizations on a topologically nontrivial manifold even if it is a finite-dimensional manifold. In this paper we consider the abelian sigma model in (1+1) dimensions to explore a system having infinite degrees of freedom. The model has a field variable $ ϕ: S^1 \to S^1 $. An algebra of the qua

A. A. Bytsenko, S. D. Odintsov, s. Zerbini

The one-loop effective action for 4-dimensional gauged supergravity with negative cosmological constant, is investigated in space-times with compact hyperbolic spatial section. The explicit expansion of the effective action as a power series of the curvature on hyperbolic background is derived, making use of heat-kernel and zeta-regularization techniques. Th

Jonathan D. Edwards

We show that it is possible to extend Moore&#39;s analysis of the classical scattering amplitudes of the bosonic string to those of the N=1 superstring. Using the bracket relations we are able to show that all possible amplitudes involving both bosonic and fermionic string states at arbitrary mass levels can be expressed in terms of amplitudes involving only

S. Scherer, H. W. Fearing

We consider Compton scattering by a pion in the framework of chiral perturbation theory. We investigate off--shell effects in the s-- and u--channel pole diagrams. For that purpose we perform a field transformation which, in comparison with the standard Gasser and Leutwyler Lagrangian, generates additional terms at order $p^4$ proportional to the lowest--ord

Thomas A. Kaeding

Pascal routines are provided that generate representations of the group $SU(3)$ and tabulate the Clebsch-Gordan coefficients in the products of representations.

Paul Langacker

There have been several important recent developments in precision electroweak tests. These include: the new LEP energy scan during the 1993 run; the first high-precision results on the left-right asymmetry from the SLD Collaboration at SLAC; the probable discovery of the top quark by the CDF Collaboration at Fermilab and the determination of its mass. I wil

Nick Evans

The S,T, and U formalism for studying electroweak precision data has recently been updated to include the effects of new light physics and within this analysis the latest LEP and SLC data tightly constrain models of physics beyond the Standard Model. We re-examine the constraints on additional strong and weakly interacting fermion families in the light of th

D. S. Du, X. L. Li, Z. J. Xiao

CP asymmetries for two-body-nonleptonic $B^{0} - \bar{B}^{0}$ decay into non-CP-eigen states are calculated using two different methods: (i) Bauer, Stech, and Wirbel factorization method to compute the decay amplitudes directly; (ii) using $B^{0}, \bar{B}^{0}$ decay amplitude ratios to avoid the direct computation of the decay amplitudes. The comparison of t

Thomas Kalkreuter

Complete spectra of the staggered Dirac operator $\Dirac$ are determined in quenched four-dimensional $SU(2)$ gauge fields, and also in the presence of dynamical fermions. Periodic as well as antiperiodic boundary conditions are used. An attempt is made to relate the performance of multigrid (MG) and conjugate gradient (CG) algorithms for propagators with th

G. E. Forden, the D0 Collaboration

\D0 has used W --> e nu events associated with a high pT jet to probe for the effects of extended source color dipole radiation in W-jet rapidity correlations. We have also studied the low energy flow in these events and shown an enhancement between the jet and the beam directions, indicating the effects of color coherency.

Daniel Boies, C. Bourbonnais, A. -M. S. Tremblay

It is shown that the Luttinger liquid is unstable to arbitrarily small transverse hopping. It becomes either a Fermi liquid or exhibits long-range order at zero temperature. The crossover temperatures below which either transverse coherent band motion or long-range order start to develop can be finite even when spin and charge velocities differ. Explicit sca

Barbara Drossel, Siegfried Clar, Franz Schwabl

We modify the rules of the self-organized critical forest-fire model in one dimension by allowing the fire to jump over holes of $\le k$ sites. An analytic calculation shows that not only the size distribution of forest clusters but also the size distribution of fires is characterized by the same critical exponent as in the nearest-neighbor model, i.e. the c

Barbara Drossel, Siegfried Clar, Franz Schwabl

We include immunity against fire as a new parameter into the self-organized critical forest-fire model. When the immunity assumes a critical value, clusters of burnt trees are identical to percolation clusters of random bond percolation. As long as the immunity is below its critical value, the asymptotic critical exponents are those of the original self-orga

M. Buongiorno Nardelli, S. Baroni, P. Giannozzi

The relative stability of different high-pressure phases of various Cesium Halides is studied from first principles and analyzed using the Landau theory of phase transitions. We present results for CsI, CsBr, and CsCl up to pressures of about 100 GPa. A cubic-to-orthorhombic transition, driven by the softening of an acoustic phonon at the M point of the Bril

Igor Ruzin, Shechao Feng

We show that any critical transition region between two adjacent Hall plateaus in either integer or fractional quantum Hall effect is characterized by a universal semi-circle relationship between the longitudinal and transverse conductivities, provided the sample is homogeneous and isotropic on a large scale. This conclusion is demonstrated both for the phas

J. P. Norris, J. T. Bonnell, R. J. Nemiroff, J. D. Scargle

We have measured the T90 and T50 durations of bright and dim gamma-ray bursts (GRBs) detected by the Compton Gamma Ray Observatory&#39;s Burst and Transient Source Experiment (BATSE). The T90 (T50) duration is defined as the interval over which 5\% (25\%) to 95\% (75\%) of the burst counts accumulate. Out of 775 bursts observed by BATSE, 159 bursts were anal

Sean Thomas Scully, Keith A. Olive

We examine galactic chemical evolution models which reproduce the present-day and pre-solar values of deuterium starting with a primordial value which is consistent with a baryon-to-photon ratio of $3 \times 10^{-10}$. We consider various galactic chemical evolution models to determine the viability of significant deuterium destruction and which provide a co

Sangjin Lee, David N. Schramm, Grant J. Mathews

We propose a self-consistent model for globular cluster formation in, but not limited to, our Galaxy, based on the merger model of Mathews and Schramm (1993). Stars and star clusters form in bursts at the merging interfaces as protogalactic clouds collide. We describe the formation of those star clusters with a simple schematic ansatz which takes into accoun

Andrew Gould

I obtain an upper limit for the optical depth to microlensing toward Baade&#39;s Window of $3\times 10^{-6}$ by assuming that all of the mass of the Galaxy interior to the Sun (and not in the bulge) is in a disk. The exponential scale height of the disk is left as a completely arbitrary function of radius and is varied to maximize the optical depth. I take a

Brian Chaboyer, P. Demarque, M. H. Pinsonneault

Stellar models with masses ranging from 0.5 to $1.3~M_\odot$ were constructed in order to compare to young cluster observations of Li and of rotation velocities. The amount of Li depletion in cool stars is sensitive to the amount of overshoot at the base of the surface convection zone, and the exact metallicity of the models. Even when this uncertainty is ta

Brian Chaboyer, P. Demarque, M. H. Pinsonneault

The Yale stellar evolution code has been modified to include the combined effects of diffusion and rotational mixing on $^1$H, $^4$He and the trace elements $^3$He, $^6$Li, $^7$Li, and $^9$Be. The interaction between rotational mixing and diffusion is studied by calculating a number of calibrated solar models. The rotational mixing inhibits the diffusion in

C. M. Baugh, E. Gaztanaga, G. Efstathiou

We present a detailed comparison of the predictions of perturbation theory for the averaged J-point correlation functions, $\xibar_J$, with the results of numerical simulations of gravitational clustering. We have carried out a systematic analysis of this method using ensembles of simulations with different numbers of particles, different box sizes and using

D. Ruffolo

In the framework of focused transport theory, adiabatic deceleration arises from adiabatic focusing in the solar wind frame and from differential solar wind convection. An explicit formula is given for the deceleration of individual particles as a function of the pitch angle. Deceleration and other first-order effects of the solar wind, including convection,

D. S. Salopek

Hamilton-Jacobi theory provides a natural starting point for a covariant description of the gravitational field. Using a spatial gradient expansion, one may solve for the phase of the wavefunction by using a line-integral in superspace. Each contour of integration corresponds to a particular choice of the time-hypersurface, and each yields the same answer. I

Dong Lai, Stu Shapiro

We employ an approximate treatment of dissipative hydrodynamics in three dimensions to study the coalescence of binary neutron stars driven by the emission of gravitational waves. The stars are modeled as compressible ellipsoids obeying a polytropic equation of state; all internal fluid velocities are assumed to be linear functions of the coordinates. The hy

Dong Lai, Stu Shapiro

We study the secular evolution and gravitational wave signature of a newly-formed, rapidly rotating neutron star. The neutron star may arise from core collapse in a massive star or from the accretion-induced collapse of a white dwarf. After a brief dynamical phase, the nascent neutron star settles into an axisymmetric, secularly unstable equilibrium state. G

E. Bagan, P. Ball, V. M. Braun, P. Gosdzinsky

We calculate the radiative corrections to the nonleptonic inclusive B decay mode $b\rightarrow c\bar u d$ taking into account the charm quark mass. Compared to the massless case, corrections resulting from a nonvanishing c quark mass increase the nonleptonic rate by (4--8)\%, depending on the renormalization point. As a by--product of our calculation, we obt

Jon Urheim

Results on semi-hadronic decays of the $τ$ lepton are presented, from studies of $e^+e^-$ annihilation data obtained at the Cornell Electron Storage Ring with the CLEO-II detector. Branching fractions have been measured for decays to two, three and four hadrons, namely $τ^-\!\!\rightarrow\! ν_τh^-π^0$, $τ^-\!\!\rightarrow\! ν_τh^-h^+h^-$, and $τ^-\!\!\righta

Cai-Dian Lu

We give a more complete calculation of $b \to sγ$ decay in 2-Higgs doublet model, including leading log QCD corrections from $m_{top}$ to $M_W$ in addition to corrections from $M_{W}$ to $m_b$. The inclusive decay rate in the first model is found to be suppressed 23\% comparing with the calculations without the QCD running from $m_{top}$ to $M_W$. And the en

Michael Freeman

We study the conserved charges of affine Toda field theories by making use of the conformally invariant extension of these theories. We compute the values of all charges for the single soliton solutions, and show that these are related to eigenvectors of the Cartan matrix of the finite-dimensional Lie algebra underlying the theory.

Tao Huang, Chuan-Wang Luo

We study light quark dependence of the Isgur-Wise function for $B_a\rightarrow D_a$ and $B_a\rightarrow D^{*}_a$ in the framework of QCD sum rules. At zero recoil , all the Isgur-Wise functions equal as required by heavy quark symmetry and at non-zero recoil, the Isgur-Wise function for $B_s$ decay falls faster than that for $B_{u,d}$ decay , which is just c

V. Berezinsky, G. Fiorentini, M. Lissia

The difficulties for non-standard solar models (NSSM) in resolving the solar neutrino problem are discussed stressing the incompatibility of the gallium--Kamiokande data, and of the gallium--chlorine data. We conclude that NSSM&#39;s cannot explain simultaneously the results of any two of the solar neutrino data (chlorine, Kamiokande and gallium). We address

A. Aurilia, E. Spallucci, I. Vanzetta

In this paper we study the dynamics of a statistical ensemble of strings, building on a recently proposed gauge theory of the string geodesic field. We show that this stochastic approach is equivalent to the Carath\'eodory formulation of the Nambu-Goto action, supplemented by an averaging procedure over the family of classical string world-sheets which are s

Omar Foda, Yas-Hiro Quano

We prove $q$-series identities between bosonic and fermionic representations of certain Virasoro characters. These identities include some of the conjectures made by the Stony Brook group as special cases. Our method is a direct application of Andrews&#39; extensions of Bailey&#39;s lemma to recently obtained polynomial identities.

P. Danielewicz

Conditions under which compression occurs and collective expansion develops in energetic reactions of heavy nuclei, are analyzed, together with their effects on emitted light baryons and pions. Within transport simulations, it is shown that shock fronts perpendicular to beam axis form in head-on reactions. The fronts separate hot compressed matter from norma

Jean-Marc Richard, Sonia Fleck

We study the domain of coupling constants for which a 3-body or 4-body system is bound while none of its subsystems is bound. Limits on the size of the domain are derived from a variant of the Hall--Post inequalities which relate $N$-body to $(N-1)$-body energies at given coupling. Possible applications to halo nuclei and hypernuclei are briefly outlined.

Nigel J. Kalton

We construct a quasi-Banach space $X$ which contains no basic sequence.

Avinash Khare, R. MacKenzie, M. B. Paranjape

The Coleman-Hill theorem prohibits the appearance of radiative corrections to the topological mass (more precisely, to the parity-odd part of the vacuum polarization tensor at zero momentum) in a wide class of abelian gauge theories in 2+1 dimensions. We re-express the theorem in terms of the effective action rather than in terms of the vacuum polarization t

I. A. Batalin, S. L. Lyakhovich, I. V. Tyutin

The split involution quantization scheme, proposed previously for pure second--class constraints only, is extended to cover the case of the presence of irreducible first--class constraints. The explicit Sp(2)--symmetry property of the formalism is retained to hold. The constraint algebra generating equations are formulated and the Unitarizing Hamiltonian is

Finn Larsen, Frank Wilczek

We develop techniques for calculating the ground state wave functional and the geometric entropy for some simple field theories. Special attention is devoted to fermions, which present special technical difficulties in this regard. Explicit calculations are carried through for free mass bosons and fermions in two dimensions, using an adaptation of Unruh&#39;

Stephen Hwang, Henric Rhedin

Explicit expressions are presented for general branching functions for cosets of affine Lie algebras $\hat{g}$ with respect to subalgebras $\hat{g}^\prime$ for the cases where the corresponding finite dimensional algebras $g$ and $g^\prime$ are such that $g$ is simple and $g^\prime$ is either simple or sums of $u(1)$ terms. A special case of the latter yield

Gil Gat, Rashmi Ray

The anomalous magnetic moment of anyons is calculated to leading order in a 1/N expansion. It is shown that the gyromagnetic ratio g remains 2 to the leading order in 1/N. This result strongly supports that obtained in \cite{poly}, namely that g=2 is in fact exact.

R. D. Tangerman, P. J. Mulders

In a nonstandard way we split up the polarized quark distributions $g_T$ and $h_L$ into their twist-two, quark-mass, and interaction-dependent parts, emphasizing the sensitivity to quark intrinsic transverse momentum. We show how to derive the Burkhardt-Cottingham sum rule in this approach and derive a similar sum rule for the chiral-odd distribution $h_2$.

Ewan D. Stewart

A globally supersymmetric model of inflation will not work in a generic supergravity theory because the higher order, nonrenormalisable supergravity corrections destroy the flatness of the inflaton&#39;s potential. In this talk I derive a form for the Kahler potential which eliminates these corrections if $ W = \partial W / \partial φ= ψ= 0 $ during inflatio

A. A. Andrianov, R. Rodenberg, N. V. Romanenko

The fine-tuning principles are examined to predict the top-quark and Higgs-boson masses. The modification of the Veltman condition based on the compensation of vacuum energies is developed. It is implemented in the Standard Model and in its minimal extension with two Higgs doublets. The top-quark and Higgs-boson couplings are fitted in the SM for the lowest