August 1998 arXiv papers — page 10

T. R. Bedding, A. A. Zijlstra

We present period-luminosity diagrams for nearby Miras and semiregulars, selecting stars with parallaxes better than 20 per cent and well-determined periods. Using K-band magnitudes, we find two well-defined P-L sequences, one corresponding to the standard Mira P-L relation and the second shifted to shorter periods by a factor of about 1.9. The second sequen

Cristopher Moore, Martin Nilsson

Given an initial distribution of sand in an Abelian sandpile, what final state does it relax to after all possible avalanches have taken place? In d >= 3, we show that this problem is P-complete, so that explicit simulation of the system is almost certainly necessary. We also show that the problem of determining whether a sandpile state is recurrent is P-com

Leonid Malyshkin, Scott Tremaine

We examine the evolution of highly eccentric, planet-crossing orbits in the restricted three-body problem (Sun, planet, comet). We construct a simple Keplerian map in which the comet energy changes instantaneously at perihelion, by an amount depending only on the azimuthal angle between the planet and the comet at the time of perihelion passage. This approxi

W. Schadow, W. Sandhas

The differential cross section for radiative capture of protons by deuterons is calculated using different realistic NN interactions. We compare our results with the available experimental data below $E_x = 20 MeV$. Excellent agreement is found when taking into account meson exchange currents, dipole and quadrupole contributions, and the full initial state i

Gary Shiu, S. -H. Henry Tye

Following Kachru, Kumar and Silverstein, we construct a set of non-supersymmetric Type II string models which have equal numbers of bosons and fermions at each mass level. The models are asymmetric {\bf Z}_2 \otimes {\bf Z}_2^{\prime} orbifolds. We demonstrate that this bose-fermi degeneracy feature implies that both the one-loop and the two-loop contributio

E. Pallante

We derive the generating functional of $|ΔS| =1, 2$ hadronic weak interactions at one loop for a generic number of flavours and its counterpart in the quenched approximation. A systematic analysis of the ultraviolet divergences in the full theory (with and without a singlet dynamical field) and in the quenched case is performed. We show that the quenched chi

A. M. Khvedelidze, H. -P. Pavel

SU(2) Yang-Mills field theory is considered in the framework of the generalized Hamiltonian approach and the equivalent unconstrained system is obtained using the method of Hamiltonian reduction. A canonical transformation to a set of adapted coordinates is performed in terms of which the Abelianization of the Gauss law constraints reduces to an algebraic op

Ph. Brax, C. Grojean, C. A. Savoy

We investigate the connection between the moduli space of N=1 supersymmetric gauge theories and the set of polynomial gauge invariants constrained by classical/quantum relations called syzygies. We examine the existence of a superpotential reproducing these syzygies and the link with the 't Hooft anomaly matching between the fundamental fields at high en

I. Vekhter, E. J. Nicol, J. P. Carbotte

We consider the attenuation of longitudinal ultrasonic waves in a clean two-dimensional d-wave superconductor. We show that the attenuation coefficient is linear in temperature at low temperatures for all in-plane directions of the propagation of the ultrasound, and that the coefficient of the linear term can be used to determine the parameters crucial for t

M. J. Duff

There has recently been a revival of interest in anti de-Sitter space (AdS) brought about by the conjectured duality beteeen physics in the bulk of AdS and a conformal field theory on the boundary. Since the whole subject of branes, singletons and superconformal field theories on the AdS boundary was an active area of research about ten years ago, I begin wi

Nir Barnea, Winfried Leidemann, Giuseppina Orlandini

The general formulation of a technically advantageous method to find the ground state solution of the Schrodinger equation in configuration space for systems with a number of particles A greater than 4 is presented. The wave function is expanded in pair correlated hyperspherical harmonics beyond the lowest order approximation and then calculated in the Fadde

F. Bouis, M. N. Kiselev

In the partition function of the Kondo lattice, spin matrices are exactly replaced by bilinear combinations of Fermi operators with the purely imaginary chemical potential lambda=-i.pi.T/2 (Popov representation). This new representation of spin operators allows one to introduce new Green's functions with Matsubara frequencies 2.pi.T(n+1/4) for S=1/2. A s

Thomas C. Kraan, Pierre van Baal

We discuss the recent construction of new exact finite temperature instanton solutions with a non-trivial value of the Polyakov loop at infinity. They can be shown, in a precise and gauge invariant way, to be formed by the superposition of n BPS monopoles for an SU(n) gauge group.

Katri Huitu, Kai Puolamäki, Da-Xin Zhang

Assuming one nonzero product of two $λ'$-type couplings and working in two different bases for the left-handed quark superfields, the neutral meson mixings are used to bound these products. We emphasize the strong basis dependence of the bounds: in one basis many products contribute to neutral meson mixings at tree level, while in the other these product

B. V. Carlson, M. S. Hussein, A. F. R. de Toledo Piza

A semiclassical description of multiple giant resonance excitation and decay that incorporates incoherent fluctuation contributions of the Brink-Axel type is developed. Numerical calculations show that the incoherent contributions are important at low to intermediate bombarding energies.

Marco M. Caldarelli, Dietmar Klemm

We examine supersymmetry of four-dimensional asymptotically anti-de Sitter (AdS) dyonic black holes in the context of gauged N=2 supergravity. Our calculations concentrate on black holes with unusual topology and their rotating generalizations, but we also reconsider the spherical rotating dyonic Kerr-Newman-AdS black hole, whose supersymmetry properties hav

L. Feher

Working at the level of Poisson brackets, we describe the extension of the generalized Wakimoto realization of a simple Lie algebra valued current, J, to a corresponding realization of a group valued chiral primary field, b, that has diagonal monodromy and satisfies $Kb'=Jb$. The chiral WZNW field b is subject to a monodromy dependent exchange algebra, w

Seungho Choe

In this work we report on a new QCD sum rule analysis to predict masses of the excited baryon states (e.g. Sigma(1620) and Lambda(1405)) by using multiquark interpolating fields ($(q\bar{q})(qqq)$). For the Sigma(1620) we consider the $\bar{K}N$, $πΣ$, and $πΛ$ (I=1) multiquark interpolating fields. The calculated mass from those multiquark states is about 1

Zixiang Zhou

For the n-dimensional integrable system with a twisted so(p,q) reduction, Darboux transformations given by Darboux matrices of degree 2 are constructed explicitly. These Darboux transformations are applied to the local isometric immersion of space forms with flat normal bundle and linearly independent curvature normals to give the explicit expression of the

Cristopher Moore, Martin Nilsson

We propose a definition of QNC, the quantum analog of the efficient parallel class NC. We exhibit several useful gadgets and prove that various classes of circuits can be parallelized to logarithmic depth, including circuits for encoding and decoding standard quantum error-correcting codes, or more generally any circuit consisting of controlled-not gates, co

Alexander N. Korotkov

We consider a continuous measurement of a two-level system (double-dot) by weakly coupled detector (tunnel point contact nearby). While usual treatment leads to the gradual system decoherence due to the measurement, we show that the knowledge of the measurement result can restore the pure wavefunction at any time (this can be experimentally verified). The fo

Raymond Y. Chiao, John C. Garrison

We reconsider the consequences of the observed violations of Bell's inequalities. Two common responses to these violations are: (i) the rejection of realism and the retention of locality, and (ii) the rejection of locality and the retention of realism. Here we critique response (i). We argue that locality contains an implicit form of realism, since in a

K. Druhl, C. Windenberger

We study a generalized notion of two-mode squeezing for the Stokes and anti-Stokes fields in a model of a cavity Raman laser, which leads to a significant reduction in decoherence or quantum noise. The model comprises a loss-less cavity with classical pump, unsaturated medium and arbitrary homogeneous broadening and dispersion. Allowing for arbitrary linear

V. A. Dzuba, V. V. Flambaum, J. K. Webb.

Theories unifying gravity and other interactions suggest the possibility of spatial and temporal variation of physical ``constants'' in the Universe. Detection of high-redshift absorption systems intersecting the sight lines towards distant quasars provide a powerful tool for measuring these variations. We have previously demonstrated that high sensi

David M. Leitner, Peter Schmelcher

We introduce a semiclassical model for moving highly excited atomic ions in a magnetic field which allows us to describe the mixing of the Landau orbitals of the center of mass in terms of the electronic excitation and magnetic field. The extent of quantum energy flow in the ion is investigated and a crossover from localization to delocalization with increas

Andrei V. Afanasev, V. D. Afanasev, S. V. Trubnikov

The root-mean square radius of the deuteron magnetic moment distribution, $ r_{Md}$, is calculated for several realistic models of the $NN$--interaction. For the Paris potential the result is $r_{Md} = 2.312 \pm 0.010 $ fm. The dependence of $r_{Md} $ on the choice of $NN$ model, relativistic effects and meson exchange currents is investigated. The experimen

Matthew Ando, Jack Morava, Hal Sadofsky

We construct splittings of some completions of the Z/(p)-Tate cohomology of E(n) and some related spectra. In particular, we split (a completion of) tE(n) as a (completion of) a wedge of E(n-1)'s as a spectrum, where t is shorthand for the fixed points of the Z/(p)-Tate cohomology spectrum (ie Mahowald's inverse limit of P_{-k} smash SE(n)). We also

K. C. H. Mackenzie

We define a general notion of abstract double Lie algebroid. We show (1) that the double Lie algebroid of a double Lie groupoid is a double Lie algebroid in this sense; (2) that the double cotangent constructed from Lie algebroid structures on a vector bundle A and its dual A* is a double Lie algebroid if and only if (A, A*) is a Lie bialgebroid; (3) that a

John Noonan, Doron Zeilberger

We initiate a general approach for the fast enumeration of permutations with a prescribed number of occurrences of `forbidden' patterns, that seems to indicate that the enumerating sequence is always P-recursive. We illustrate the method completely in terms of the patterns `abc',`cab' and `abcd'.

Doron Zeilberger

The Rev. Dodgson's determinant condensation rule is given a bijective proof.

Doron Zeilberger

A combinatorial problem that came up in Combinatorial Chemistry is solved.

Shalosh B. Ekhad, Doron Zeilberger

John Horton Conway's Cosmological Theorem, about Audioactive sequences, for which no extant proof existed, is given a computer-generated proof, hopefully for good.

Doron Zeilberger

David Brydges and Thomas Spencer's Lace Expansion is abstracted, and it is shown how it sometimes gives rise to sieves.

Mirko Luedde, Alexei Vladimirov

Yang-Baxter bialgebras, as previously introduced by the authors, are shown to arise from a double crossproduct construction applied to the bialgebra R T T = T T R, E T = T E R, Δ(T) = T \hat{\otimes} T, Δ(E) = E \hat{\otimes} T + 1 \hat{\otimes} E and its skew dual, with R being a numerical matrix solution of the Yang-Baxter equation. It is further shown tha

Dan Abramovich, Frans Oort

In this short note, we propose a definition of complete Hurwitz schemes (and stacks) in mixed characteristic. We follow an idea of R. Pandharipande, and define the complete Hurwitz stack as a substack of stable maps of degree d of nodal pointed curves of genus g to the universal curve over the moduli stack of stable pointed curves of genus h. This substack i

Mikhail Grinenko

It is proved that the group of birational automorphisms of a three-dimensional double quadric with a singular point arising from a double point on the branch divisor is a semidirect product of the free group generated by birational involutions of a special form and the group of regular automorphisms. The proof is based on the method of `untwisting' maxim

Peter W. Michor, Josef Teichmann

It is shown that every abelian regular Lie group is a quotient of its Lie algebra via the exponential mapping.

James A. Gifford, Alexander V. Isaev, Steven G. Krantz

We study the possible dimensions that the groups of holomorphic automorphisms of hyperbolic Reinhardt domains can have. We are particularly interested in the problem of characterizing Reinhardt domains with automorphism group of prescribed dimension.

N. Ilieva, W. Thirring

We construct solutions to the chiral Thirring model in the framework of algebraic quantum field theory. We find that for all positive temperatures there are fermionic solutions only if the coupling constant is $λ= \sqrt{2(2n + 1)π}, n \in \bf N$.

G. S. Sharov

The considered model of baryon consists of three pointlike masses (quarks) bounded pairwise by relativistic strings forming a curvilinear triangle. Classic analytic solutions for this model corresponding to a planar uniform rotation about the system center of mass are found and investigated. These solutions describe a rotating curve composed of segments of a

Giovanni Amelino-Camelia

It is observed that some structures recently uncovered in the study of Calogero-Sutherland models and anyons are close analogs of well-known structures of boundary conformal field theory. These examples of ``boundary conformal quantum mechanics'', in spite of their apparent simplicity, have a rather reach structure, including some sort of T-duality,

Alexey A. Petrov

Using the operator product expansion and nonrelativistic QCD we study the production of charmonium hybrids in B decays. We express the decay rate in terms of a few matrix elements which eventually will be fixed by experimental measurements or calculated on the lattice. While the Fock state expansion is problematic for hybrids, the operator product expansion

P. R. Page, E. S. Swanson, A. P. Szczepaniak

The phenomenology of a newly developed model of hybrid meson decay is developed. The decay mechanism is based on the heavy quark expansion of QCD and the strong coupling flux tube picture of nonperturbative glue. A comprehensive list of partial decay widths of a wide variety of light, $s\bar s$, $c\bar c$, and $b \bar b$ hybrid mesons is presented. Results w

E. Petitgirard

At finite temperature a breakdown of the hard thermal loop expansion arises whenever external momenta are light-like or tend to very soft scales. A resummation of ladder graphs is important in these cases where the effects of infrared or light-cone singularities are enhanced. We show that in hot QED another class of diagrams is also relevant at leading order

Paolo Gondolo

I show that it may be possible to explain the present evidence for a gamma-ray emission from the galactic halo as due to halo WIMP annihilations. Not only the intensity and spatial pattern of the halo emission can be matched but also the relic density of the candidate WIMP can be in the cosmologically interesting domain. After a model-independent analysis to

A. A. Bykov, V. Yu. Popov, A. I. Rez, V. B. Semikoz

The magnetic field in the convective zone of the Sun has a random small-scale component with the r.m.s. value substantially exceeding the strength of a regular large-scale field. For two Majorana neutrino flavors $\times$ two helicities in the presence of a neutrino transition magnetic moment and nonzero neutrino mixing we analyze the displacement of the all

H. Hamidian, K. Huitu, K. Puolamäki, D. -X. Zhang

We study a class of generalized models of gauge mediated supersymmetry breaking (GMSB). We find the parameters and the full particle spectrum of the minimal supersymmetric standard model (MSSM) for all GMSB models with messenger multiplicities that satisfy the perturbativity of the gauge couplings up to the GUT scale. We give a detailed description of the al

N. Armesto, J. Bartels, M. A. Braun

It is shown that solutions to the 2nd order BFKL eigenvalue equation exist for arbitrary large real values of the complex angular momentum $j$. This corresponds to a cut in the complex $j$ plane along the whole real axis, and it makes the use of the complex angular momentum variable for the calculation of the high-energy behavior somewhat questionable. The e

C. B. Yang, X. Cai

The scaled factorial moments in second-order quark-hadron phase transition are reexamined within the Ginzburg-Landau description, with the spatial fluctuations of phase angle of the complex field $ϕ$ taken into account rigorously. Scaling behaviors between $F_q$ and $F_2$ are shown, and the exponent $ν$ is found very close to the one without spatial fluctuat

U. Sharan, M. Teper

We calculate the spectral density of the Dirac operator over an ensemble of configurations composed of overlapping instantons and anti-instantons. We find evidence that the spectral density diverges in the limit of small eigenvalues. This indicates the breaking of chiral symmetry and also provides evidence that quenched QCD may be pathological in nature.

UKQCD Collaboration, C. R. Allton, S. P. Booth, K. C. Bowler

We present the first results for the static quark potential and the light hadron spectrum using dynamical fermions at $β=5.2$ using an O(a) improved Wilson fermion action together with the standard Wilson plaquette action for the gauge part. Sea quark masses were chosen such that the pseudoscalar-vector mass ratio, m_PS/m_V$, varies from 0.86 to 0.67. Finite

C. Adloff

Interactions of the type ep -> eXY are studied, where the component X of the hadronic final state contains two jets and is well separated in rapidity from a leading baryonic system Y. Analyses are performed of both resolved and direct photoproduction and of deep-inelastic scattering with photon virtualities in the range 7.5 < Q^2 < 80 GeV^2. Cross sections a

The OPAL Collaboration, K. Ackerstaff et al

The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured cross-section agrees well with the expectation from QED. A fit to the angular distribution is used to obtain improved limits a

Giovanni Amelino-Camelia

Several proposals for Quantum Gravity involve length and area operators with discrete eigenvalues. I show that the analyses of some simple procedures for the measurement of areas and lengths suggest that this discreteness characterizing the formalism might not be observable. I also discuss a possible relation with the so-called $κ$ deformations of Poincare&#

Giovanni Amelino-Camelia

Quantum Mechanics is revisited as the appropriate theoretical framework for the description of the outcome of experiments that rely on the use of classical devices. In particular, it is emphasized that the limitations on the measurability of (pairs of conjugate) observables encoded in the formalism of Quantum Mechanics reproduce faithfully the ``classical-de

Clive G. Wells

We make use of an internal symmetry of a truncation of the bosonic sector of the superstring and N=4 supergravity theories to write down an analogue of Robinson&#39;s identity for the black holes of this theory. This allows us to prove the uniqueness of a restricted class of black hole solutions. In particular, we can apply the methods of the preceding paper

Veronika E. Hubeny

We show that, contrary to a widespread belief, one can overcharge a near extremal Reissner-Nordstrom black hole by throwing in a charged particle, as long as the backreaction effects may be considered negligible. Furthermore, we find that we can make the particle&#39;s classical radius, mass, and charge, as well as the relative size of the backreaction terms

P. Kleban, A. E. Ozluk

We introduce a new number-theoretic spin chain and explore its thermodynamics and connections with number theory. The energy of each spin configuration is defined in a translation-invariant manner in terms of the Farey fractions, and is also expressed using Pauli matrices. We prove that the free energy exists and exhibits a unique phase transition at inverse

M. J. Bojan, G. Stan, S. Curtarolo, W. A. Steele

We report studies of the wetting behavior of Ne on very weakly attractive surfaces, carried out with the Grand Canonical Monte Carlo method. The Ne-Ne interaction was taken to be of Lennard-Jones form, while the Ne-surface interaction was derived from an ab initio calculation of Chizmeshya et al. Nonwetting behavior was found for Li, Rb, and Cs in the temper

L. Zekri, N. Zekri, R. Bouamrane, F. Brouers

We Study in this paper the scaling and statistical properties of the $ac$ conductivity of thin metal-dielectric films in different regions of the loss in the metallic components and particularly in the limit of vanishing loss. We model the system by a 2D $RL-C$ network and calculate the effective conductivity by using a real space renormalization group metho

Tao Xiang

Thermodynamic properties of the quantum Heisenberg spin chains with S = 1/2, 1, and 3/2 are investigated using the transfer-matrix renormalization-group method. The temperature dependence of the magnetization, susceptibility, specific heat, spin-spin correlation length, and several other physical quantities in a zero or finite applied field are calculated an

N. Markovic, C. Christiansen, A. M. Goldman

The superconductor-insulator transition in ultrathin films of amorphous Bi was tuned by changing the film thickness, with and without an applied magnetic field. The first experimentally obtained phase diagram is mapped as a function of thickness and magnetic field in the T=0 limit. A finite size scaling analysis has been carried out to determine the critical

P. van der Schoot, J. P. Wittmer

The problem of ring formation in solutions of cylindrical micelles is reinvestigated theoretically, taking into account a finite bending rigidity of the self-assembled linear objects. Transitions between three regimes are found when the scission energy is sufficiently large. At very low densities only spherical and very short, rod-like micelles form. Beyond

G. F. Glinskii, K. O. Kravchenko

Method of invariants is used to obtain effective kp-Hamiltonian with position-dependent band parameters and correct boundary conditions for electron and hole envelope functions in A3B5-heterostructures with arbitrary interface orientation. It is shown that the presence of heterointerface yields additional quadratic-in-k and linear-in-k terms in kinetic energ

D. Lynden-Bell, R. M. Lynden-Bell

We solve the N-body problems in which the total potential energy is any function of the mass-weighted root-mean-square radius of the system of N point masses. The fundamental breathing mode of such systems vibrates non-linearly for ever. If the potential is supplemented by any function that scales as the inverse square of the radius there is still no damping

S. Artz, S. Trimper

Using a quantum formulation of the master equation we study a kinetic Ising model with competing stochastic processes: the Glauber dynamics with probability $p$ and the Kawasaki dynamics with probability $1 - p$. Introducing explicitely the coupling to a heat bath and the mutual static interaction of the spins the model can be traced back exactly to a Ginzbu

H. T. C. Stoof, M. Houbiers

We present an overview of the various phase transitions that we anticipate to occur in trapped fermionic alkali gases. We also discuss the prospects of observing these transitions in (doubly) spin-polarized Li-6 and K-40 gases, which are now actively being studied by various experimental groups around the world.

Jeppe C. Dyre

Recent NMR experiments on supercooled toluene and glycerol by Hinze and Bohmer show that small rotation angles dominate with only few large molecular rotations. These results are here interpreted by assuming that viscous liquids are solid-like on short length scales. A characteristic length, the &#34;solidity length&#34;, separates solid-like behavior from l

V. N. Kotov, O. P. Sushkov, R. Eder

We study the excitation spectrum of the two-chain S=1/2 Heisenberg spin ladder with additional inter-chain second-neighbor frustrating interactions. The one and two-particle excitations are analyzed by using a mapping of the model onto a Bose gas of hard-core triplets. We find that low-lying singlet and triplet two-particle bound states are present and their

Francesco Miniati, Dongsu Ryu, Andrea Ferrara, T. W. Jones

We extend previous studies of the physics of interstellar cloud collisions by beginning investigation of the role of magnetic fields through 2D magnetohydrodynamic (MHD) numerical simulations. We study head-on collisions between equal mass, mildly supersonic diffuse clouds. We include a moderate magnetic field and two limiting field geometries, with the fiel

Amri Wandel

Probably the most fundamental characteristic of the quasar-AGN power house, the mass of the central black hole, is the least well known. I review the three main classes of mass estimation methods---broad emission-line kinematics, X-ray variability and accretion-disk modeling, and the masses they give in terms of the Eddington ratio, $L/L_{\rm Edd}$. The broa

Mou Roy, H. J. Crawford

In this paper we give a brief systematic study of different models of astrophysical point sources of ultra high energy (\ge 1 TeV) neutrinos.

Paul B. Eskridge, Richard W. Pogge

Polar-ring galaxies are systems with two nearly orthogonal rotational axes, and are therefore clearly the result of galaxy-galaxy interactions. The host galaxies of polar rings are typically gas-poor early-type systems. The rings themselves, however, are typically gas-rich, blue, star-forming systems. They have traditionally been modelled as the remnants of

L. K. Hunt, M. A. Malkan, G. Moriondo, M. Salvati

We have derived the near-infrared structural components of a sample of Seyfert and starburst (SBN) host galaxies by fitting the images of Hunt et al. (1997,ApJS,108,229) with a new two-dimensional decomposition algorithm. An analysis of the fitted parameters shows that Seyfert 1 and SBN bulges resemble normal early-type bulges in structure and color, with (J

Emilio Molinari, Guido Chincarini, Alberto Moretti, Sabrina De Grandi

Deep photometric observations in three colours of the cluster A 496 show that the luminosity function is bimodal with a deep gap at g about 19.0. That is there is a net separation between E/SO galaxies that are nicely fitted by a gaussian distribution curve and the dwarfs that better match a Shechter Function. This is the first cluster observed and reduced o

J. W. Sulentic, P. Marziani, D. Dultzin-Hacyan

We review the evidence for AGN optical and X-ray broad line emission from an accretion disk. We argue that there is little, if any, statistical evidence to support this assertion. The inconsistency is strongest for the rare class of Balmer profiles that show double peaks. The line profiles predicted by a simple illuminated disk model are often incompatible w

V. Avila-Reese, C. Firmani

We study the formation of hot spheroidal systems within the frame of a scenario where galaxy formation and evolution is related to the gentle mass aggregation history and primordial angular momentum of protogalaxies, both defined by the cosmological initial conditions. We explore two cases: (1) the hot spheroidal system forms from the dynamical instabilities

L. Staveley-Smith, S. Juraszek, B. S. Koribalski, R. D. Ekers

We present the first results of a blind HI survey for galaxies in the southern Zone of Avoidance with a multibeam receiver on the Parkes telescope. This survey is eventually expected to catalog several thousand galaxies within Galactic latitude |b|<5 degrees, mostly unrecognised before due to Galactic extinction and confusion. We present here results of the

Victor Chernyak

It is shown that there is no chirally symmetric vacuum state in the {cal N}=1 supersymmetric Yang-Mills theory. The values of the gluino condensate and the vacuum energy density are found out through a direct instanton calculation. A qualitative picture of domain wall properties is presented, and a new explanation of the phenomenon of strings ending on the w

Roy Maartens, Tim Gebbie, George Ellis

We develop a new approach to local nonlinear effects in cosmic microwave background anisotropies, and discuss the qualitative features of these effects. New couplings of the baryonic velocity to radiation multipoles are found, arising from nonlinear Thomson scattering effects. We also find a new nonlinear shear effect on small angular scales. The full set of

S. R. Patel, D. R. Stewart, C. M. Marcus, M. Gokcedag

The temperature dependence of Coulomb blockade peak height correlation is used to investigate how adding electrons to a quantum dot alters or &#34;scrambles&#34; its electronic spectrum. Deviations from finite-temperature random matrix theory with an unchanging spectrum indicate spectral scrambling after a small number of electrons are added. Enhanced peak-t

R. Arad, L. Ding, Y. Maron

A novel method for doping plasmas in pulsed-power experiments with gaseous elements has been developed. A fast gas valve, a nozzle, and a skimmer are used to generate an ultrasonic gas beam that is injected into a planar-geometry microsecond plasma-opening-switch (POS). An array of ionization probes with relatively high spatial and temporal resolutions was d

U. A. Wiedemann, J. Ellis, U. Heinz, K. Geiger

We discuss algorithms which allow to calculate identical two-particle correlations from numerical simulations of relativistic heavy ion collisions. A toy model is used to illustrate their properties.

Robert L. Foote

The Prytz planimeter is a simple example of a system governed by a non-holonomic constraint. It is unique among planimeters in that it measures something more subtle than area, combining the area, centroid and other moments of the region being measured, with weights depending on the length of the planimeter. As a tool for measuring area, it is most accurate

Eduardo Esteves

In the 80&#39;s D. Eisenbud and J. Harris developed the general theory of limit linear series, Invent. math. 85 (1986), in order to understand what happens to linear systems and their ramification points on families of non-singular curves degenerating to curves of compact type. They applied their theory to the study of limits of Weierstrass points, among oth

J. N. Moore, E. P. S. Shellard

We study the evolution of abelian-Higgs string networks in numerical simulations. These are compared against a modified velocity-dependent one scale model for cosmic string network evolution. This incorporates the contributions of loop production, massive radiation and friction to the energy loss processes that are required for scaling evolution. We find tha

O. V. Teryaev

The density matrix positivity is a natural counterpart of unitarity. The resulting constraints for various parton distribution and correlations are considered. Their compatibility with leading order QCD evolution is guaranteed by the probabilistic interpretation of the latter. In the case of non-forward distributions the positivity constraints naturally impl

Clive G. Wells

We present black hole uniqueness theorems for the C-metric and Ernst solution. The proof follows a similar strategy as that used to prove the uniqueness of the Kerr-Newman solution, however the presence of an acceleration horizon provides some critical differences. We also show how to derive the Bunting/Mazur result (on the positivity of a suitable divergenc

D. F. Wang

In this letter, I consider the issue of pricing risky debt by following Merton&#39;s approach. I generalize Merton&#39;s results to the case where the interest rate is modeled by the CIR term structure. Exact closed forms are provided for the risky debt&#39;s price.

H. J. Schulz

The two-chain model of correlated fermions, appropriate e.g. for doped spin ladders or carbon nanotubes, is investigated in the weak-interaction limit. It is shown that the model scales to situations with high internal symmetries, generically SO(6), whereas on critical lines there is SO(5) or SO(3) symmetry. Consequences for the level spectroscopy of the mod

A. I. Smirnov, M. N. Popova, A. B. Sushkov, S. A. Golubchik

We found anomalies in the temperature dependence of the dielectric and the magnetic susceptibiliy of NaV_2O_5 in the microwave and far infrared frequency ranges. The anomalies occur at the phase transition temperature T_c, at which the spin gap opens. The real parts of the dielectric constants epsilon_a and epsilon_c decrease below T_c. The decrease of epsil

Yukitaka Ishimoto

3d Chern-Simons gauge theory has a strong connection with 2d CFT and link invariants in knot theory. We impose some constraints on the $D(2|1;α)$ CS theory in the similar context of the hamiltonian reduction of 2d superconformal algebras. There Hilbert states in $D(2|1;α)$ CS theory are partly identified with characters of the large N=4 SCFT by their transfo

Todd A. Brun, James B. Hartle

We consider a number of proposals for the entropy of sets of classical coarse-grained histories based on the procedures of Jaynes, and prove a series of inequalities relating these measures. We then examine these as a function of the coarse-graining for various classical systems, and show explicitly that the entropy is minimized by the finest-grained descrip

Dinesh K. Srivastava, Klaus Geiger

In view of the recent WA98 data of pi0 spectra from central Pb+Pb collisions at the CERN SPS, we analyze the production of neutral pions for A+$ collisions across the periodic table at sqrt(s)=17 AGeV and 200 AGeV within the framework of the parton-cascade model for relativistic heavy ion collisions. The multiplicity of the pions (having pT > 0.5 GeV/c) in t

Saharon Shelah

We deal with (< kappa)-supported iterated forcing notions which are (E_0,E_1)-complete, have in mind problems on Whitehead groups, uniformizations and the general problem. We deal mainly with the successor of a singular case. This continues [Sh:587]. We also deal with complimentary combinatorial results.

Saharon Shelah

We prove that if mu^+< lambda =cf(lambda)< mu^{aleph_0}, then there is no universal reduced torsion free abelian group. Similarly if aleph_0< lambda < 2^{aleph_0}. We also prove that if 2^{aleph_0}< mu^+< lambda =cf(lambda)< mu^{aleph_0}, then there is no universal reduced separable abelian p-group in lambda. (Note: both results fail if lambda = lambda^{alep

Todd Eisworth, Saharon Shelah

We investigate the existence of strong colorings on successors of singular cardinals. This work continues Section 2 of [Sh:413] (math.LO/9809199), but now our emphasis is on finding colorings of pairs of ordinals, rather than colorings of finite sets of ordinals.

Lucian M. Ionescu

To characterize categorical constraints - associativity, commutativity and monoidality - in the context of quasimonoidal categories, from a cohomological point of view, we define the notion of a parity (quasi)complex. Applied to groups gives non-abelian cohomology. The categorification - functor from groups to monoidal categories - provides the correspondenc

C. P. Sun, D. L. Zhou

In the view of the quantum dynamic theory of measurement developed from the Hepp-Colemen (HC) model (K. Hepp, Hev.Phys.Acta, {\bf 45}, 237 (1972)), the quantum decoherence in neutrino flavor oscillation caused by an environment surrounding neutrinos is generally considered in this paper. The Ellis, Hagelin, Nanopoulos and Srednicki (EHNS) mechanism for solvi

J. W. Moffat

An overview of unified theory models that extend the standard model is given. A scenario describing the physics beyond the standard model is developed based on a finite quantum field theory (FQFT) and the group G=$SO(3,1)\otimes SU(3)\otimes SU(2)\otimes U(1)$. The field theory is Poincaré invariant, gauge invariant, finite and unitary to all orders of pertu