April 1997 arXiv papers — page 8

D. Coffey

I investigate the difference between the quasiparticle properties in two dimensional(2D)and three dimensional(3D) s-wave superconductors. Using the original BCS model for the pairing interaction and direct Coulomb interaction I show that quasiparticle interactions lead to a stronger energy dependence in the single-particle self-energies in 2D than in 3D supe

Lee Lindblom, Gregory Mendell, James R. Ipser

A new method is presented here for evaluating approximately the pulsation modes of relativistic stellar models. This approximation relies on the fact that gravitational radiation influences these modes only on timescales that are much longer than the basic hydrodynamic timescale of the system. This makes it possible to impose the boundary conditions on the g

C. D. Fosco

Halpern's field strength's formulation of gauge theories is applied to effective QED_3, namely, a gauge invariant theory for an Abelian gauge field $A_μ$ with non-localities and self-interactions. The resulting description in terms of the pseudovector field $\tilde{F}_μ= ε_{μνλ}\partial_νA_λ$ is applied to different examples.

Stephen L. Adler, G. G. Emch

In a series of papers published in this Journal (J. Math. Phys.), a discussion was started on the significance of a new definition of projective representations in quaternionic Hilbert spaces. The present paper gives what we believe is a resolution of the semantic differences that had apparently tended to obscure the issues.

E. Bergshoeff, M. de Roo, E. Eyras, B. Janssen

We consider intersections in eleven dimensions involving Kaluza-Klein monopoles and Brinkmann waves. Besides these purely gravitational configurations we also construct solutions to the equations of motion that involve additional M2- and M5-branes. The maximal number of independent objects in these intersections is nine, and such maximal configurations, when

R. G. Gratton, F. Fusi Pecci, E. Carretta, G. Clementini

We report here initial but still strongly conclusive results on absolute ages of galactic globular clusters (GGCs). This study is based on high precision trigonometric parallaxes from the HIPPARCOS satellite coupled with accurate metal abundances ([Fe/H], [O/Fe], and [\alpha/Fe]) from high resolution spectroscopy for a sample of about thirty subdwarfs. Syste

P. Fraundorf

We take J. S. Bell's commendation of ``frame-dependent'' perspectives to the limit here, and consider motion on a ``map'' of landmarks and clocks fixed with respect to a single arbitrary inertial-reference frame. The metric equation connects a traveler-time with map-times, yielding simple integrals of constant proper-acceleration over spa

M. Hayakawa

The possibility that the mass hierarchy is intimately associated with the compositeness level of the matters is proposed in supersymmetric gauge theory. This implies, for instance, that the preons constituting top quark consists of the ``prepreons'' binded by the same gauge force making the charm quark out of another preons. The exemplifying toy mode

A. N. Ivanov, N. I. Troitskaya, M. Faber, H. Oberhummer

The relativistic field theory model of the deuteron is applied to the calculation of the cross sections of the low-energy radiative neutron-proton capture n + p -> D + gamma and the low-energy two-proton fusion p + p -> D + e^+ + nu_e. For the low-energy radiative neutron-proton capture n + p -> D + gamma our result agrees well with both the experimental dat

Keiichi Akama, Kazuo Katsuura, Hidezumi Terazawa

The significant excess of events recently found by the H1 and ZEUS Collaborations at HERA in the deep-inelastic e^+ p scattering for high momentum-transfers squared Q^2>15000 GeV^2 over the expectation of the standard model can be explained by either one of the following possible consequences of the substructure of quarks and leptons: 1) production of leptoq

Masanao Ozawa

The halt scheme for quantum Turing machines, originally proposed by Deutsch, is reformulated precisely and is proved to work without spoiling the computation. The ``conflict'' pointed out recently by Myers in the definition of a universal quantum computer is shown to be only apparent. In the context of quantum nondemolition (QND) measurement, it is a

G. Bimonte, R. Musto, A. Stern, P. Vitale

We construct a Chern-Simons action for q-deformed gauge theory which is a simple and straightforward generalization of the usual one. Space-time continues to be an ordinary (commuting) manifold, while the gauge potentials and the field strengths become q-commuting fields. Our approach, which is explicitly carried out for the case of `minimal' deformation

Didier Sornette, Anders Johansen

We propose that large stock market crashes are analogous to critical points studied in statistical physics with log-periodic correction to scaling. We extend our previous renormalization group model of stock market prices prior to and after crashes [D. Sornette et al., J.Phys.I France 6, 167, 1996] by including the first non-linear correction. This predicts

M. B. Hecht, B. H. J. McKellar

The electric and magnetic dipole moments of the rho meson are calculated using the propagators and vertices derived from the QCD Dyson-Schwinger equations. Results obtained from using the Bethe-Salpeter amplitude studied by Chappell, Mitchell and Tandy, and Pichowsky and Lee, are compared. The rho meson EDM is generated through the inclusion of a quark elect

A. C. Maggs

Conflicting experimental results have been reported for the plateau modulus in actin solutions: Analogies are often made with the viscoelastic behaviour of flexible polymers making use of the idea of entanglement as the source of the macroscopic storage modulus. We resolve apparent experimental and theoretical contradictions by pointing out the possibility o

Toshio Nakatsu

A framework of second-quantization of D5-branes is proposed. It is based on the study of topology of the moduli space of their low energy effective worldvolume theory. Among the topological cycles which resolve singularities caused by overlapping D5-branes, it is introduced those cycles which duals, constituting a subspace of cohomology group of the moduli s

Won T. Kim, Myungseok Yoon

The generalized kinetic term of a dilaton gives the classical superinflation without recourse to any potential, and the quantum version of the dilaton gravity exhibits the finite curvature and graceful exit. For $p=2$ case, the model corresponds to the RST quantization of the s-wave sector of the four-dimensional Einstein cosmology. Further, the de Sitter un

Katsuji Koyama, Kenzo Kinugasa, Keiichi Matsuzaki, Mamiko Nishiuchi

We report ASCA results of a featureless X-ray spectrum from RX J1713.7-3946, a new shell-like SNR discovered with the ROSAT all sky survey. The northwest part of RX J1713.7-3946 was in the field of the ASCA Galactic Plane Survey Project and was found to exhibit a shell-like structure. The spectrum, however shows neither line emission nor any signature of a t

M. Shifman

I give an introductory review of recent, fascinating developments in supersymmetric gauge theories. I explain pedagogically the miraculous properties of supersymmetric gauge dynamics allowing one to obtain exact solutions in many instances. Various dynamical regimes emerging in supersymmetric Quantum Chromodynamics and its generalizations are discussed. I em

Michael Birkel, Ramon Toldra

It has been recently suggested that magnetically affected neutrino oscillations inside a cooling protoneutron star, created in a supernova explosion, could explain the large proper motion of pulsars. We investigate whether this hypothesis is in agreement with the observed properties of pulsars and find that present data disfavor the suggested mechanism. The

Zurab Kakushadze, Gary Shiu, S. -H. Henry Tye

Using the bosonic supercurrent (or covariant lattice) formalism, we review how to compute scattering amplitudes in asymmetric orbifold string models. This method is particularly useful for calculating scattering of multiple asymmetrically twisted string states, where the twisted states are rewritten as ordinary momentum states. We show how to reconstruct som

Gregorio Falqui, Cesare Reina, Alessandro Zampa

We study the geometrical meaning of the Faa' di Bruno polynomials in the context of KP theory. They provide a basis in a subspace W of the universal Grassmannian associated to the KP hierarchy. When W comes from geometrical data via the Krichever map, the Faa' di Bruno recursion relation turns out to be the cocycle condition for (the Welters hypercoh

Charles W. Clark

An infinite family of closed-form solutions is exhibited for the Schroedinger equation for the potential $V(r) = -Z/\sqrt{|r|^{2} + a^{2}}$. Evidence is presented for an approximate dynamical symmetry for large values of the angular momentum $l$.

J. L. Friar, G. L. Payne

Nuclear-polarizability corrections that go beyond unretarded-dipole approximation are calculated analytically for hydrogenic (atomic) S-states. These retardation corrections are evaluated numerically for deuterium and contribute -0.68 kHz, for a total polarization correction of 18.58(7) kHz. Our results are in agreement with one previous numerical calculatio

Jean-Marc Gambaudo, Élisabeth E. Pécou

By considering the way an n-tuple of points in the 2-disk are linked together under iteration of an orientation preserving diffeomorphism, we construct a dynamical cocycle with values in the Artin braid group. We study the asymptotic properties of this cocycle and derive a series of topological invariants for the diffeomorphism which enjoy rich properties.

David J. Grabiner

A partition of the positive integers into sets $A$ and $B$ {\em avoids} a set $S\subset\N$ if no two distinct elements in the same part have a sum in $S$. If the partition is unique, $S$ is {\em uniquely avoidable.} For any irrational $α>1$, Chow and Long constructed a partition which avoids the numerators of all convergents to $α$, and conjectured that the

W. Fischler, A. Rajaraman

We conjecture that M-theory compactified on an ALE space (or K3) is described by 0-branes moving on the ALE space. We give evidence for this by showing that if we compactify another circle, we recover string theory on the ALE space. This guarantees that in the large N limit, the matrix model correctly describes the force law between gravitons moving in an AL

H. Aratyn, A. Das, C. Rasinariu

We generalize the Drinfeld-Sokolov formalism of bosonic integrable hierarchies to superspace, in a way which systematically leads to the zero curvature formulation for the supersymmetric integrable systems starting from the Lax equation in superspace. We use the method of symmetric space as well as the non-Abelian gauge technique to obtain the supersymmetric

B. Sathiapalan

We describe a method of writing down the exact interacting gauge invariant equations for all the modes of the bosonic open string. It is a generalization of the loop variable approach that was used earlier for the free, and lowest order interacting cases. The generalization involves, as before, the introduction of a parameter to label the different strings i

Chris Quigg

Extended version of an article on top-quark physics, to appear in the May 1997 issue of Physics Today.

Jonathan L. Rosner

Our picture of the electroweak interactions continues to improve, with ever more precise constraints on the masses of the Higgs boson(s) and on non-standard physics. Some recent developments include: (a) a calculation of higher-order effects on the weak mixing angle which reduces scheme-dependence, (b) a long-awaited improvement in the experimental accuracy

Jurij W. Darewych

The complex scalar quantum field theory with a lambda (phi^*phi)^2 interaction is considered in the Feshbach-Villars formulation. It is shown that exact few-particle eigenstates of the QFT Hamiltonian can be obtained. The resulting relativistic few-body equations correspond to Klein-Gordon particles interacting via delta-function, or ``contact'', pot

Mannque Rho, Vicente Vento

Quantum effects inside the chiral bag induce a color anomaly which requires a compensating surface term to prevent breakdown of color gauge invariance. We show that the presence of this surface term first discovered several years ago allows one to derive in a gauge-invariant way a chiral-bag version of the Shore-Veneziano two-component formula for the flavor

A. H. Hoang

It is demonstrated how perturbative O(alpha_s^2) relativistic corrections to the non-relativistic stable heavy quark-antiquark production cross section in e^+e^- annihilation based on a Coulombic QCD potential can be systematically calculated using the concept of effective field theories. The O(alpha_s^2) corrections from the relativistic energy-momentum rel

M. Gasperini

We derive a generalized equation for the evolution of tensor perturbations in a cosmological background, taking into account higher-curvature contributions and a tree-level coupling to the dilaton in the string frame. The equation is obtained by perturbing the gravi-dilaton string effective action, expanded up to first order in $α'$. The $α'$ correct

Andrzej Królak

The problem of search for nearly periodic gravitational wave sources in the data from laser interferometric detectors is discussed using a simple model of the signal. Accuracies of estimation of the parameters and computational requirements to do the search are assessed.

J. W. van Holten

In these lectures general relativity is outlined as the classical field theory of gravity, emphasizing physical phenomena rather than mathematical formalism. Dynamical solutions representing traveling waves as well as stationary fields like those of black holes are discussed. Their properties are investigated by studying the geodesic structure of the corresp

Kip S. Thorne

A summary is given of the current status and plans for gravitational-wave searches at all plausible wavelengths, from the size of the observable universe to a few kilometers. The anticipated scientific payoff from these searches is described, including expectations for detailed studies of black holes and neutron stars, high-accuracy tests of general relativi

Guillermo A. Mena Marugan

The family of Gowdy universes with the spatial topology of a three-torus is studied both classically and quantum mechanically. Starting with the Ashtekar formulation of Lorentzian general relativity, we introduce a gauge fixing procedure to remove almost all of the non-physical degrees of freedom. In this way, we arrive at a reduced model that is subject onl

Andrei V. Frolov

This paper studies the perturbations of the continuously self-similar critical solution of the gravitational collapse of a massless scalar field (Roberts solution). The perturbation equations are derived and solved exactly. The perturbation spectrum is found to be not discrete, but occupying continuous region of the complex plane. The renormalization group c

Toshifumi Sakaguchi

The paper entitled ``Against Many-Worlds Interpretations'' by A. Kent, which has recently been submitted to the e-Print archive (gr-qc/9703089) contained some misconceptions. The claims on Everett's many-worlds interpretation are quoted and answered.

Vladimir S. Mashkevich

This paper is a continuation of the papers [gr-qc/9409010, gr-qc/9505034, gr-qc/9603022, gr-qc/9609035, gr-qc/9609046, gr-qc/9704033]. The aim of the paper is to incorporate singularities---both local (black hole and naked singularity) and global (big bang and big crunch)---into the dynamics of indeterministic quantum gravity and cosmology. The question is w

T. Blum, M. A. Moore

We calculate the Aslamazov-Larkin term of the conductivity in the presence of a magnetic field applied along the c-axis from the time-dependent Ginzburg-Landau equation perturbatively using two approaches. In the first a uniform electric field is explicitly applied; in the second the Kubo formula is used to extract the linear response. The former yields a ve

D. Chang, C. -Y. Mou, B. Rosenstein, C. L. Wu

We describe effects of anisotropy caused by the crystal lattice in d-wave superconductors with s-wave mixing using the effective free energy approach. Only the d-wave order parameter field $d$ is introduced, while the effect of the s wave mixing as well as other effects breaking the rotational symmetry down to the fourfold symmetry of the crystal are represe

S. N. Artemenko, S. V. Remizov

The reflection of electrons incident from a normal metal on the boundary of the metal with a quasi-one-dimensional conductor containing a charge-density wave (CDW) is investigated theoretically. It is shown that the reflection is not of an Andreev character, as it was suggested earlier, but rather of a Bragg character. This is due to the fact that the CDW is

Alexander Altland, Martin R. Zirnbauer

In a recent comment [cond-mat/9703106] Casati, Izrailev and Sokolov claim that our analysis of the quantum kicked rotor [Phys. Rev. Lett. 77, 4536 (1996), chao-dyn/9609014] seems to miss an important aspect, viz. the difference in behavior between rational and irrational values of the parameter T = tau/4pi (tau being the time between kicks). The fact of the

Eric Cockayne, Karin M. Rabe

In the substitutionally disordered narrow-gap semiconductor Pb_{1-x}Ge_xTe, a finite-temperature cubic-rhombohedral transition appears above a critical concentration $x \approx 0.005$. As a first step towards a first-principles investigation of this transition in the disordered system, a (hypothetical) ordered cubic Pb_3GeTe_4 supercell is studied. First pri

Brett Ellman, Mark Sutton, Benoit Lussier, Ralf Bruning

Using synchrotron radiation-based Laue diffraction methods, we have searched for structural anomalies in a single-crystal whisker of the heavy fermion superconductor UPt_3. Our data cover a large volume of k-space with high sensitivity. We find no signs of the structural modulations seen in transmission electron microscopy studies of whiskers grown under ide

Yue Yu, Zongyuan Zhu

We derive a microscopic theory of the composite fermion type quasiparticles describing the low-lying edge excitations in the fractional quantum Hall liquid with $ν=1/m$. Using the composite fermion transformation, one finds that the edge states of the system in a disc sample are described by the Calogero-Sutherland-like model (CSLM) in the one-dimensional li

Marilyn A. Walker, Diane J. Litman, Candace A. Kamm, Alicia Abella

This paper presents PARADISE (PARAdigm for DIalogue System Evaluation), a general framework for evaluating spoken dialogue agents. The framework decouples task requirements from an agent's dialogue behaviors, supports comparisons among dialogue strategies, enables the calculation of performance over subdialogues and whole dialogues, specifies the relativ

Doron Cohen

We try to clarify what are the genuine quantal effects that are associated with generalized Brownian Motion (BM). All the quantal effects that are associated with the Zwanzig-Feynman-Vernon-Caldeira-Leggett model are (formally) a solution of the classical Langevin equation. Non-stochastic, genuine quantum mechanical effects, are found for a model that takes

J. A. de Freitas Pacheco, J. E. Horvath

We consider in this work continuous gravitational wave (GW) emission from non-axisymmetric radio pulsars. We treat in some detail the observational issues related to the known radio pulsar sample with the aim of unveiling the actual number of sources contributing to GW, which are likely to be the main contributors of GWs. It is shown that the operation of sp

Smita Mathur

This talk discusses the unified X-ray/UV absorption models in AGN. I will first review the models and discuss how they offer an unique opportunity to probe the near nuclear environment of AGNs. Recently, however, the validity of these models has been questioned by a number of authors. I will discuss these papers and argue that the data/ models presented in t

V. V. Usov, M. V. Smolsky

The interaction between a wide ultrarelativistic fully-ionized plasma beam and a magnetic barrier is studied numerically. It is assumed that the plasma beam is initially homogeneous and impacts with the Lorentz factor $Γ_0\gg 1$ on the barrier. The magnetic field of the barrier $B_0$ is uniform and transverse to the beam velocity. When the energy densities o

Steve Rawlings, Katherine M. Blundell, Mark Lacy, Chris J. Willott

We use the K-z relation for radio galaxies to illustrate why it has proved difficult to obtain definitive cosmological results from studies based entirely on catalogues of the brightest radio sources, e.g. 3C. To improve on this situation we have been undertaking redshift surveys of complete samples drawn from the fainter 6C and 7C radio catalogues. We descr

T. Koehler, D. Groote, D. Reimers, L. Wisotzki

We present the analysis of a new flux-limited sample of bright quasars and Seyfert 1 galaxies in an effective area of 611 square deg, drawn from the Hamburg/ESO survey. We confirm recent claims that bright quasars have a higher surface density than previously thought. Special care was taken to avoid morphological and photometric biases against low-redshift q

Guinevere Kauffmann, Stephane Charlot

In this paper, we present a model of the formation and chemical enrichment of elliptical galaxies that differs from the conventional picture in two ways: 1)Ellipticals do not form in a single monolithic collapse and burst of star formation at high redshift. Instead, most of their stars form at modest rates in disk galaxies, which then merge to form the ellip

I. Georgantopoulos, G. C. Stewart, A. J. Blair, T. Shanks

We present ASCA GIS observations (total exposure 100-200 ksec) of three fields which form part of our deep ROSAT survey. We detect 26 sources down to a limiting flux (2-10 keV) of 5x10^{-14} erg cm-2 s-1. Sources down to this flux level contribute 30 per cent of the 2-10 keV X-ray background. The number-count distribution, logN-logS, is a factor of three abo

J. -M. Deharveng, S. Faisse, B. Milliard, V. Le Brun

The H-alpha luminosity density of galaxies is used to calculate the local diffuse radiation field at the Lyman limit as resulting from star formation in the universe. The fraction of Lyman continuum radiation leaking out from galaxies through their neutral hydrogen is the most uncertain parameter of the calculation. A comparison of the diffuse radiation pred

A. Sornborger, R. Brandenberger, B. Fryxell, K. Olson

We present results of a cosmological hydrodynamical study of gravitational accretion in cosmic string wakes and filaments. Cosmic string wakes are formed by fast moving (v ~ c) strings. A conical deficit angle in the string spacetime induces a velocity perturbation in the background matter and a two-dimensional wake accretes in the path of the string. Filame

Isabelle Baraffe, Gilles Chabrier, France Allard, Peter Hauschildt

We have performed evolutionary calculations of very-low-mass stars from 0.08 to 0.8 $\msol$ for different metallicites from [M/H]= -2.0 to -1.0 and we have tabulated the mechanical, thermal and photometric characteristics of these models. The calculations include the most recent interior physics and improved non-grey atmosphere models. The models reproduce t

J. Bland-Hawthorn, P. R. Maloney

There has been much debate in recent decades as to what fraction of ionizing photons from star forming regions in the Galactic disk escape into the halo. The recent detection of the Magellanic Stream in optical line emission at the CTIO 4m and the AAT 3.9m telescopes may now provide the strongest evidence that at least some of the radiation escapes the disk

J. Bland-Hawthorn, G. N. Cecil

Tunable filters are set to revolutionize many aspects of experimental astrophysics, particularly for applications in observational cosmology. After a summary of the fundamentals of classical spectroscopy, we present a review of the current technologies on offer. For extragalactic studies, small-gap etalons are the preferred option in terms of cost, photometr

J. Bland-Hawthorn

We summarize recent attempts to detect warm ionized gas at large galactocentric distances. This includes searching for gas at the edges of spirals, in between cluster galaxies, towards extragalactic HI clouds, and towards high velocity clouds and the Magellanic Stream in the Galaxy. With the exception of extragalactic HI clouds, all of these experiments have

Matthew G. Baring, Alice K. Harding, Peter L. Gonthier

Gamma-rays from pulsars can be efficiently attenuated in their magnetospheres via the mechanism of single-photon pair production and also the exotic QED process of photon splitting, which become prolific in fields approaching the quantum critical value of $B_{cr}=4.41\times 10^{13}$ Gauss. Recently we have published results of our modelling of strongly-magne

Matthew G. Baring, Donald C. Ellison, Isabelle Grenier

While the definitive detection of gamma-rays from known supernova remnants (SNRs) remains elusive, the collection of unidentified EGRET sources that may be associated with SNRs has motivated recent modelling of TeV emission from these sources. Current theoretical models use power-law shock-accelerated protons and electrons in their predictions of expected ga

H. Andernach, A. G. Gubanov, O. B. Slee

Gravitational lensing (GL) of distant radio sources by galaxy clusters should produce radio arc(let)s. We extracted radio sources from the FIRST survey near Abell cluster cores and found their radio position angles to be uniformly distributed with respect to the cluster centres. This result holds even when we restrict the sample to the richest or most centra

Geir Ellingsrud, Manfred Lehn

We prove that the Quot-scheme of finite quotients of a vector bundle which are of a given length and supported in one point, is irreducible and of the expected dimension.

Shigeru Mukai

A Brill-Noether locus is a subscheme of the moduli of bundles E over a curve C defined by requiring E to have a given number of sections, or homomorphisms from another bundle. There are a number of different types, that can be treated by determinantal methods, with symmetry or skewsymmetry arising from Serre duality. They have many beautiful applications to

Igor R. Klebanov, Arvind Rajaraman, Arkady A. Tseytlin

We consider five-dimensional black holes modeled by D-strings bound to D5-branes, with momentum along the D-strings. We study the greybody factors for the non-minimally coupled scalars which originate from the gravitons and R-R antisymmetric tensor particles polarized along the 5-brane, with one index along the string and the other transverse to the string.

B. W. Harris, J. F. Owens

A new next-to-leading order Monte Carlo program for the calculation of jet cross sections in photoproduction is described. The contributions from both resolved and direct components are included to O(αα_s^2). Properties of the predictions for various inclusive jet and dijet observables are discussed and comparisons with HERA data are presented.

A. H. Castro Neto, C. de C. Chamon, C. Nayak

We study the problem of Luttinger liquids interacting with an active environment. We are particularly interested in how dissipation affects the response and correlation functions of non-isolated Luttinger liquids. We show that the exchange of particles, energy, and momentum lead to changes in the exponents characterizing the various correlations functions. W

A M Semikhatov, I Yu Tipunin

We classify degeneration patterns of Verma modules over the N=2 superconformal algebra in two dimensions. Explicit formulae are given for singular vectors that generate maximal submodules in each of the degenerate cases. The mappings between Verma modules defined by these singular vectors are embeddings; in particular, their compositions never vanish. As a b

Ramzi R. Khuri

These lectures are intended as an introduction to some of the basic aspects of string solitons, duality and black holes. We begin with a discussion of the role of classical solutions in duality, then focus on string/string duality and fundamental membranes. Finally, we examine the feature of compositeness of string solitons, and its implications for bound st

T. M. Aliev, M. Savci, A. Ozpineci, H. Koru

The decay width, forward-backward asymmetry and lepton longitudinal and transversal polarization for the exclusive K^* -> l^+ l^- decay in a two Higgs doublet model are computed. It is shown that all these quantities are very effective tools for establishing new physics.

R. Bijker, A. Leviatan

We discuss an algebraic treatment of three-body systems in terms of a U(7) spectrum generating algebra. In particular, we develop the formalism for nonlinear configurations and present an algebraic description of vibrational and rotational excitations of symmetric (X_3) and asymmetric tops (XY_2 and XYZ). The relevant point group symmetry is incorporated exa

Nathan Berkovits

It was earlier shown that an SO(9,1) $θ^\a$ spinor variable can be constructed from RNS matter and ghost fields. $θ^\a$ has a bosonic worldsheet super-partner $λ^\a$ which plays the role of a twistor variable, satisfying $λΓ^μλ= \partial x^μ+iθΓ^μ\partialθ$. For Type IIA superstrings, the left-moving $[θ_L^\a,λ_L^\a]$ and right-moving $[θ_{R\a},λ_{R\a}]$ can

O. Almaini, T. Shanks, R. E. Griffiths, B. J. Boyle

We present a cross-correlation analysis to constrain the faint galaxy contribution to the cosmic X-ray background (XRB). Cross-correlating faint optical galaxy catalogues with unidentified X-ray sources from 3 deep ROSAT fields we find that B < 23 galaxies account for 20+-7 % of all X-ray sources to a flux limit of S(0.5-2.0 keV)=4x10^{-15} erg s-1 cm-2. To

Richard Cleve, Harry Buhrman

We show that quantum entanglement can be used as a substitute for communication when the goal is to compute a function whose input data is distributed among remote parties. Specifically, we show that, for a particular function among three parties (each of which possesses part of the function&#39;s input), a prior quantum entanglement enables one of them to l

L. R. Abramo, R. H. Brandenberger, V. M. Mukhanov

We study the effective energy-momentum tensor (EMT) for cosmological perturbations and formulate the gravitational back-reaction problem in a gauge invariant manner. We analyze the explicit expressions for the EMT in the cases of scalar metric fluctuations and of gravitational waves and derive the resulting equations of state. The formalism is applied to inv

C. A. Mosbacher, F. Osterfeld

The 2H(p,n) charge exchange reaction at T_p=790 MeV is used to study the Delta(1232)-nucleon interaction in the Delta resonance excitation energy region. For the Delta-N potential, a meson exchange model is adopted where pi, rho, omega, and sigma meson exchanges are taken into account. The deuteron disintegration below and above pion threshold is calculated

P. Zavada

It is shown that the quark-parton model in the standard infinite momentum approach overestimate the proton spin structure function $g_1(x)$ in comparison with the approach taking consistently into account the internal motion of quarks described by a spherical phase space in the proton rest frame. Particularly, it is shown the first moment of the spin structu

Lajos Diosi

The e-print is completely withdrawn for it was based on a report which was not public. The author seriously apologizes because he was unaware.

David S. Graff, Gregory Laughlin, Katherine Freese

(Abridged Abstract) A favored interpretation of recent microlensing measurements towards the Large Magellanic Cloud implies that a large fraction (i.e. 10--50%) of the mass of the galactic halo is composed of white dwarfs. We compare model white dwarf luminosity functions to the data from the observational surveys in order to determine a lower bound on the a

I. M. Dremin, V. A. Nechitailo, M. Biyajima, N. Suzuki

Theoretical prediction of oscillations of cumulant moments of parton multiplicity distributions inside a jet supported by experimental data in some multiple production processes asks for analysis of the phenomenon for the whole set of available reactions. We have found out that the oscillations persist in any kind of processes and increase for particles with

J. Erdmenger

We discuss conformally covariant differential operators, which under local rescalings of the metric, δ_σg^{μν} = 2 σg^{μν}, transform according to δ_σΔ= r Δσ+ (s-r) σΔfor some r if Δis s-th order. It is shown that the flat space restrictions of their associated Green functions have forms which are strongly constrained by flat space conformal invariance. The

Bjarne Thomsen, William A. Baum, Mark Hammergren, Guy Worthey

We report on the first determination of the distance to the Coma Cluster based on surface brightness fluctuation (SBF) measurements obtained from Hubble Space Telescope WFPC2 observations of the bright E0 galaxy NGC 4881 in the Coma Cluster and ground-based observations of the standard E1 galaxy NGC 3379 in the Leo-I group. Relative distances based on the I-

M. P. Dabrowski, M. A. Hendry

We use the redshift-magnitude relation, as derived by Dcabrowski (1995), for the two exact non-uniform pressure spherically symmetric Stephani universes with the observer positioned at the center of symmetry, to test the agreement of these models with recent observations of high redshift type Ia supernovae (SNIa), as reported in Perlmutter et al. (1997). By

Hiroshi Suzuki, Hirofumi Yasuta

On the basis of Borel resummation, we propose a systematical improvement of bounce calculus of quantum bubble nucleation rate. We study a metastable super-renormalizable field theory, $D$ dimensional O(N) symmetric $ϕ^4$ model ($D<4$) with an attractive interaction. The validity of our proposal is tested in D=1 (quantum mechanics) by using the perturbation s

Alexander Burinskii

A combined model of the Kerr spinning particle and superparticle is considered. The structure of the Kerr geometry is presented in a complex form as being created by a complex source. A natural supergeneralization of this construction is obtained corresponding to a complex &#34;supersource&#34;. Peforming a supershift to the Kerr and Kerr-Sen solutions we ob

S. James Gates,, V. G. J. Rodgers

We provide world sheet non-supersymmetrical actions that describe the coupling of a bosonic string to the tachyon and massless states of both the type-B and type-O theories. The type-B theory is derived as a truncation and chiral doubling of the Ramond-Ramond sector in our previous model that connected the (1,0) heterotic string to a 10 D type IIB supergravi

Eue Jin Jeong

The negative mass squared problem of the recent neutrino experiments from the five major institutions prompts us to speculate that, after all, neutrinos may be tachyons. There are number of reasons to believe that this could be the case. Stationary neutrinos have not been detected. There is no evidence of right handed neutrinos which are most likely to be ob

Andrew Chamblin

We classify elementary particles according to their behaviour under the action of the full inhomogeneous Lorentz group. For fundamental fermions, this approach leads us to delineate fermions into eight basic families or `types', corresponding to the eight simply connected double covering groups of the inhomogeneous Lorentz group (the `pin' groups). Given thi

Gilles Brassard, Peter Hoyer

We investigate the power of quantum computers when they are required to return an answer that is guaranteed to be correct after a time that is upper-bounded by a polynomial in the worst case. We show that a natural generalization of Simon&#39;s problem can be solved in this way, whereas previous algorithms required quantum polynomial time in the expected sen

V. A. Skrebnev, R. N. Zaripov

An experimental study of the applicability of mechanics equations to describing the process of equilibrium establishing in an isolated spin system was performed. The time-reversion effects were used at the experiments. It was demonstrated, that the equations of mechanics do not describe the spin macrosystem transition to the equilibrium. The experimental res

Luis Gonzalez-Mestres

If textbook Lorentz invariance is actually a property of the equations describing a sector of the excitations of vacuum above some critical distance scale, several sectors of matter with different critical speeds in vacuum can coexist and an absolute rest frame (the vacuum rest frame) may exist without contradicting the apparent Lorentz invariance felt by &#

M. Yu. Kuchiev

A theory of the Post-Collision Interaction (PCI) is developed for the case when an electron atom impact results in creation of two low-energy Wannier electrons and an ion excited into an autoionizing state. The following autoionization decay exposes the Wannier pair to the influence of PCI resulting in variation of the shape of the line in the autoionization

Fred Cooper, James M. Hyman, Avinash Khare

We study a class of generalized fifth order Korteweg-de Vries (KdV) equations which are derivable from a Lagrangian L(p,m,n,l) which has variable powers of the first and second derivatives of the field with powers given by the parameters p,m,n,l. The resulting field equation has solitary wave solutions of both the usual (non-compact) and compact variety (&#3

A. M. Rucklidge, Mary Silber

Motivated by recent analytical and numerical work on two- and three-dimensional convection with imposed spatial periodicity, we analyse three examples of bifurcations from a continuous group orbit of spatio-temporally symmetric periodic solutions of partial differential equations. Our approach is based on centre manifold reduction for maps, and is in the spi

A. L. Barabanov

The T-noninvariant transverse polarization of neutrons is considered for muon capture by a 6-Li nucleus with decay into a quasistationary 2+ state of the three particle alpha+n+n continuum. This polarization is orthogonal to the plane spanned by the polarization axis of the initial mesic atom and the neutron momentum. The situation in which neutrons that are