November 1998 arXiv papers — page 17

C. Bourdarios

Using D$^{*+}$ mesons exclusively reconstructed in the DELPHI detector at LEP, orbital and radial excitations of non strange charmed mesons are studied. The multiplicities of the two narrow $D^0_1$ and $D^{*0}_2$ orbital excitations are measured in $Z^0 \to c \bar c$ and $Z^0 \to b \bar b$ decays. Preliminary results are obtained on the production of broad D

C. Adloff

Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T <= MeV, for events with a final state proton with

NuTeV Collaboration, T. Adams

A preliminary analysis of zero hadronic energy dimuon production in the NuTeV experiment is presented (nu_mu (anti-nu_mu) + N -> nu_mu(anti-nu_mu) + mu^+ + mu^- + N). The data show a signal in excess of background which is attributed to neutrino trident production. This excess is consistent with the Standard Model prediction including electroweak interferenc

Marco Cavaglia

In cosmology minisuperspace models are described by nonlinear time-reparametrization invariant systems with a finite number of degrees of freedom. Often these models are not explicitly integrable and cannot be quantized exactly. Having this in mind, we present a scheme for the (approximate) quantization of perturbed, nonintegrable, time-reparametrization inv

Egon Boerger, James K. Huggins

An annotated bibliography of papers which deal with or use Abstract State Machines (ASMs), as of January 1998.

Phil Bernstein, Michael Brodie, Stefano Ceri, David DeWitt

The database research community is rightly proud of success in basic research, and its remarkable record of technology transfer. Now the field needs to radically broaden its research focus to attack the issues of capturing, storing, analyzing, and presenting the vast array of online data. The database research community should embrace a broader research agen

Robert M. Ziff, Christian D. Lorenz, Peter Kleban

The shape-dependent universality of the excess percolation cluster number and cross-configuration probability on a torus is discussed. Besides the aspect ratio of the torus, the universality class depends upon the twist in the periodic boundary conditions, which for example are generally introduced when triangular lattices are used in simulations.

M. B. Hastings

The large N commensurate dirty boson model, in both the weakly and strongly commensurate cases, is considered via a perturbative renormalization group treatment. In the weakly commensurate case, there exists a fixed line under RG flow, with varying amounts of disorder along the line. Including 1/N corrections causes the system to flow to strong disorder, ind

Francis W. Starr, Johannes K. Nielsen, H. Eugene Stanley

We study hydrogen-bond dynamics in liquid water at low temperatures using molecular dynamics simulations. We find that bond lifetime (``fast dynamics&#39;&#39;) has Arrhenius temperature dependence. We also calculate the bond correlation function and find that the correlation time (``slow dynamics&#39;&#39;) shows power-law behavior. This power-law behavior,

Francis W. Starr, Marie-Claire Bellissent-Funel, H. Eugene Stanley

An open question is whether the liquid and glassy phases of water are thermodynamically distinct or continuous. Here we address this question using molecular dynamics simulations in comparison with neutron scattering experiments to study the effect of temperature and pressure on the local structure of liquid water. From both simulations and experiments, we f

M. Leadbeater, C. J. Lambert, R. Raimondi, A. F. Volkov

We study the sub-gap conductance of a ferromagnetic mesoscopic region attached to a ferromagnetic and a superconducting electrode by means of tunnel junctions. In the absence of the exchange field, the ratio $r= γ/ ε_T$ of the two tunnel junction resistances determines the behaviour of the sub-gap conductance which possesses a zero-bias peak for $r\gg 1$ and

Michele Cini, Adalberto Balzarotti, Gianluca Stefanucci

Highly-symmetric three-band Hubbard Cu-O clusters have peculiar properties when the hole number is such that they admit W=0 hole pairs. These are two-hole eigenstates of the on-site Hubbard repulsion with eigenvalue 0, get bound by correlation effects when dressed by the interaction with the background, and cause superconducting flux quantization. We study t

A. Klümper, A. A. Zvyagin

Exact results for the thermodynamic properties of ensembles of magnetic impurities with randomly distributed host-impurity couplings in the quantum antiferromagnetic Heisenberg model are presented. Exact calculations are done for arbitrary values of temperature and external magnetic field. We have shown that for strong disorder the quenching of the impurity

Lei-Han Tang, Guang-Shan Tian

Several models of stock trading [P. Bak et al, Physica A {\bf 246}, 430 (1997)] are analyzed in analogy with one-dimensional, two-species reaction-diffusion-branching processes. Using heuristic and scaling arguments, we show that the short-time market price variation is subdiffusive with a Hurst exponent $H=1/4$. Biased diffusion towards the market price and

Malek Zareyan, A. N. Omelyanchouk

A theory is offered for the ballistic 4-terminal Josephson junction. The studied system consists of a mesoscopic two-dimensional normal rectangular layer which is attached in each side to the bulk superconducting banks (terminals). The relation between the currents through the different terminals, which is valid for arbitrary temperatures and junction sizes,

Xiao-Gang Wen

Using projective construction, a generalized parton construction, we construct many non-Abelian quantum Hall (QH) states, which include the Pfaffian state at filling fraction $ν=1/2$. The projective construction allows us to calculate the bulk and the edge effective theory for the constructed QH state. We illustrate how to use the bulk effective theory to ca

S. Park, B. Kahng

We introduce an interface growth model exhibiting a nonequilibrium roughening transition (NRT). In the model, particles consist of two species, and deposit or evaporate on one dimensional substrate according to a given dynamic rule. When the dynamics is limited to occur on monolayer, this model has two absorbing states, belonging to the directed Ising (DI) u

P. Castiglione, A. Mazzino, P. Muratore-Ginanneschi, A. Vulpiani

The superdiffusion behavior, i.e. $<x^2(t)> \sim t^{2 ν}$, with $ν> 1/2$, in general is not completely characherized by a unique exponent. We study some systems exhibiting strong anomalous diffusion, i.e. $<|x(t)|^q> \sim t^{q ν(q)}$ where $ν(2)>1/2$ and $q ν(q)$ is not a linear function of $q$. This feature is different from the weak superdiffusion regime,

Sebastien Blais-Ouellette, Claude Carignan, Philippe Amram

In the last 20 years, rotation curves derived from H I kinematics obtained on radio synthesis instruments were used to probe the dark matter distribution in spiral and dwarf irregular galaxies. It is shown, with the aid of the Sd galaxy NGC 5585, that high resolution 2--D H II kinematics is necessary to determine accurately the mass distribution of spirals.

Claus Heerlein, Keith Horne, Axel D. Schwope

We present a magnetic stripping model for AM Her type objects. Our model is based on an equilibrium condition between ram pressure and magnetic pressure in a stiff dipolar magnetic field. We investigate the detailed geometry of the stripping process, most of which can be tackled analytically. By involving additional numerical calculations, the model allows t

J. -U. Fischer, G. Hasinger, A. D. Schwope, H. Brunner

The ROSAT Bright Survey (RBS) aims to completely optically identify the more than 2000 brightest sources detected in the ROSAT all-sky survey at galactic latitudes |b| > 30 degr (excluding LMC, SMC, Virgo cluster). This paper presents a subsample of 66 bright point-like ROSAT survey sources with almost hard PSPC spectra, the hardness ratio HR1 is > 0.5 for m

Peter D. Edmonds, Jonathan E. Grindlay, Adrienne M. Cool, Haldan N. Cohn

We have used HST/FOS to study faint UV stars in the core of the nearby globular cluster NGC 6397. We confirm the presence of a 4th cataclysmic variable (CV) in NGC 6397 (CV 4), and we use the photometry of Cool et al. (1998) to present evidence that CVs 1--4 all have faint disks and probably low accretion rates. By combining these results with new UV spectra

Terry Bridges

I summarize recent observations of the kinematics of hot tracers in elliptical galaxy halos (globular clusters, planetary nebulae, and integrated stellar light), and what these tell us about the dynamics, dark matter content, and formation of ellipticals. A generic result is the ubiquity of dark matter halos in ellipticals. Studies of globular clusters and p

Norman Cruz, Sergio del Campo, Ramon Herrera

We investigate the possibility that the matter of the universe has a significant component (the quintessence component) determined by the equation of state $p=wρ$, with $w<0$. Here, we find conditions under which a closed model may look like a flat Friedmann-Robertson-Walker universe at low redshift. We study this problem in Einstein&#39;s general relativity

F. Combes

Mass accretion is the key factor for evolution of galaxies. It can occur through secular evolution, when gas in the outer parts is driven inwards by dynamical instabilities, such as spirals or bars. This secular evolution proceeds very slowly when spontaneous, and can be accelerated when triggered by companions. Accretion can also occur directly through merg

M. A. T. Groenewegen

Our current knowledge of carbon stars in the Local Group and beyond, is discussed. Although many carbon stars and late M-stars have been identified in external galaxies a coherent understanding in terms of the chemical evolution- and star formation rate-history of a galaxy is still largely lacking. Issues that need to be addressed are: 1) for some of the lar

Laura Greggio, Alvio Renzini

Recent observational and theoretical developments concerning the origin of the ultraviolet emission from ellipticals are reviewed and discussed,with particular, reference to the extensive set of predictions contained in Greggio and Renzini (1990). Strong support to the preferred hot horizontal branch and AGB-manque&#39; scenario for the origin of the UV emis

C. Horellou, V. Charmandaris, F. Combes, P. N. Appleton

We present the first detection of molecular gas in the Cartwheel, the prototype of a collisional ring galaxy formed in the head-on encounter of two galaxies. Until now, only very little atomic gas and no CO had been detected in the centre, where gas is theoretically expected to pile up. Using the Swedish ESO Submm Telescope, we detected both 12CO(1-0) and (2

F. Herwig, T. Bloecker, D. Schoenberner

We investigate the influence of convective overshoot on stellar evolution models of the thermal pulse AGB phase with M_ZAMS = 3 Msol. An exponential diffusive overshoot algorithm is applied to all convective boundaries during all evolutionary stages. We demonstrate that overshooting at the bottom of the pulse-driven convective zone, which forms in the inters

T. X. Thuan, M. Sauvage, S. Madden

The metal deficient (Z = Z_sun/41) Blue Compact Dwarf Galaxy (BCD) SBS 0335-052 was observed with ISOCAM between 5 and 17 mic. With a L_12mic/L_B ratio of 2.15, the galaxy is unexpectedly bright in the mid-infrared for such a low-metallicity object. The mid-infrared spectrum shows no sign of the Unidentified Infrared Bands, which we interpret as an effect of

M. E. Putman, B. K. Gibson, L. Staveley-Smith

The first results from the HI Parkes All-Sky Survey (HIPASS) provide a spectacular view of the global HI distribution in the vicinity of the Magellanic Clouds and the southern Milky Way. A 2400 square degree mosaic around the South Celestial Pole (SCP) reveals the existence of a narrow, continuous counter-stream which &#39;leads&#39; the direction of motion

Kenji Bekki, Yasuhiro Shioya

We numerically investigate chemodynamical evolution of major disk-disk galaxy mergers in order to explore the origin of mass-dependent chemical, photometric, and spectroscopic properties observed in elliptical galaxies. We particularly investigate the dependence of the fundamental properties on merger progenitor disk mass (M_d). Main results obtained in this

D. Boyanovsky, H. J. de Vega, R. Holman, J. Salgado

We analyze the non-equilibrium dynamics of the O(N) Phi^4 model in the large N limit and for states of large energy density. The dynamics is dramatically different when the energy density is above the top of the tree level potential V_0 than when it is below it.When the energy density is below V_0, we find that non-perturbative particle production through sp

M. A. Nielsen, E. Knill, R. Laflamme

Quantum mechanics provides spectacular new information processing abilities (Bennett 1995, Preskill 1998). One of the most unexpected is a procedure called quantum teleportation (Bennett et al 1993) that allows the quantum state of a system to be transported from one location to another, without moving through the intervening space. Partial implementations o

C. J. Isham, J. Butterfield

In a previous paper, we have proposed assigning as the value of a physical quantity in quantum theory, a certain kind of set (a sieve) of quantities that are functions of the given quantity. The motivation was in part physical---such a valuation illuminates the Kochen-Specker theorem; and in part mathematical---the valuation arises naturally in the topos the

V. R. Manfredi, L. Salasnich

In this paper we discuss in detail the nonlinear equations of the mean--field approximation and their connection to the exact many--body Schrödinger equation. Then we analyze the mean--field approach and the nonlinear dynamics of a trapped condensate of weakly--interacting bosons.

E. Prodan

A practical solution for the mathematical problem of functional calculus with Laplace-Beltrami operator on surfaces with axial symmetry is found. A quantitative analysis of the spectrum is presented.

William F. Langford, Kaijun Zhan

A codimension-three bifurcation, characterized by a pair of purely imaginary eigenvalues and a nonsemisimple double zero eigenvalue, arises in the study of a pair of weakly coupled nonlinear oscillators with Z_2 + Z_2 symmetry. The methodology is based on Arnold&#39;s ideas of versal deformations of matrices for the linear analysis, and Poincaré normal forms

Vitaly Tarasov

Recently N.Jing discovered a certain combinatorial identity from validity of the Serre relations in some vertex representations of quantum Kac-Moody algebras. We generalize this identity, in particular, extending it from polynomials to elliptic functions, and interprete the obtained identities in terms of tensor products of evaluation representations of the

Eli Hawkins

Using the classification of formal deformation quantizations, and the formal, algebraic index theorem, I give a simple proof as to which formal deformation quantization (modulo isomorphism) is derived from a given geometric quantization.

Vitaly Tarasov

We discuss the hypergeometric solutions of the quantized Knizhnik-Zamolodchikov (qKZ) equation at level zero and show that they give all solutions of the qKZ equation. We completely describe linear relations between the hypergeometric solutions and give an interpretation of the relations in terms of the quantum group $U_q(sl_2)$ at $q=e^{πi/2}$.

Edward Stredulinsky, William P. Ziemer

In this paper we consider the problem of minimizing area subject to a volume constraint in a given convex set.

Makoto Ozawa

We show that free genus of knots is additive under connected sum.

P. P. Kulish, A. I. Mudrov

Sufficient conditions for an invertible two-tensor $F$ to relate two solutions to the Yang-Baxter equation via the transformation $R\to F^{-1}_{21} R F$ are formulated. Those conditions include relations arising from twisting of certain quasitriangular bialgebras.

Sultan Catto

Algebraic realizations of supersymmetry through SU(m,n) type superalgebras are developed. We show their applications to a bilocal quark-antiquark or a quark-diquark systems. A new scheme based on SU(6/1) is fully exploited and the bilocal approximation is shown to get carried unchanged into it. Color algebra based on octonions allows the introduction of a ne

S. S. e Costa, H. V. Fagundes

We propose a modified form of the spontaneous birth of the universe by quantum tunneling. It proceeds through topology change and inflation, to eventually become a universe with closed spatial sections of negative curvature and nontrivial global topology.

A. Priel, I. Kanter

We study the effect of various transfer functions on the properties of a time series generated by a continuous-valued feed-forward network in which the next input vector is determined from past output values. The parameter space for monotonic and non-monotonic transfer functions is analyzed in the unstable regions with the following main finding; non-monoton

Asok K. Sen

We study localization properties of a one-dimensional disordered system characterized by a random non-hermitean hamiltonian where both the randomness and the non-hermiticity arises in the local site-potential; its real part being ordered (fixed), and a random imaginary part implying the presence of either a random absorption or amplification at each site. Th

Jordi Ignes-Mullol, Jean Baudry, Lubor Lejcek, Patrick Oswald

We have studied the nucleation and the physical properties of a -1/2 wedge disclination line near the free surface of a confined nematic liquid crystal. The position of the disclination line has been related to the material parameters (elastic constants, anchoring energy and favored anchoring angle of the molecules at the free surface). The use of a planar m

Uros Seljak, Matias Zaldarriaga

We show that time dependent gravitational potential can be directly detected from the cosmic microwave background (CMB) anisotropies. The signature can be measured by cross-correlating the CMB with the projected density field reconstructed from the weak lensing distortions of the CMB itself. The cross-correlation gives a signal whenever there is a time depen

C. Gallart, W. L. Freedman, M. Mateo, C. Chiosi

We present deep HST F555W (V) and F814W (I) observations of a central field in the Local Group dwarf spheroidal (dSph) galaxy Leo I. The resulting color-magnitude diagram (CMD) reaches I \simeq 26 and reveals the oldest ~10-15 Gyr old turnoffs. Nevertheless, a horizontal branch is not obvious in the CMD. Given the low metallicity of the galaxy, this likely i

D. E. Harris, J. D. Silverman, G. Hasinger, I. Lehmann

X-ray observations with the ROSAT High Resolution Imager (HRI) often have spatial smearing on the order of 10 arcsec (Morse 1994). This degradation of the intrinsic resolution of the instrument (5 arcsec) can be attributed to errors in the aspect solution associated with the wobble of the space craft or with the reacquisition of the guide stars. We have deve

Eric A. Richards

Determination of the epoch dependent star-formation rate of field galaxies is one of the principal goals of modern observational cosmology. Deep radio surveys, sensitive to starbursts out to $z \sim$ 1-2, may hold the key to understanding the evolution of the starburst phenonemon unhindered by the effects of dust. Using deep, high resolution radio observatio

Elcio Abdalla, Roya Mohayaee

We derive the time evolution of the density contrast to all orders of perturbation theory, by solving the Einstein equation for scale-invariant fluctuations. These fluctuations are represented by an infinite series in inverse powers of the radial parameter. In addition to the standard growing modes, we find infinitely many more new growing modes for open and

A. G. Gubanov, V. P. Reshetnikov

The detailed identifications of the FIRST and NVSS radio sources with optical objects in APM and in DSS surveys are carried out for 26 rich Abell clusters of galaxies. 99 radio sources are identified with optical objects, 40 have probable identifications, and 187 are not identified from 326 radio sources in the considered fields (within Abell radius of each

Kenji Bekki

A significant fraction of clusters of galaxies are observed to have substructure, which implies that merging between clusters and subclusters is a rather common physical process of cluster formation. It still remains unclear how cluster merging affects the evolution of cluster member galaxies. We report the results of numerical simulations, which show the dy

Rita Sambruna, Michael Eracleous, Richard Mushotzky

We summarize the results of an X-ray spectroscopic survey of radio-loud AGNs observed with ASCA, using proprietary and archival data (public up to 1998 September). We briefly compare our results with those obtained for radio-quiet AGNs studied by other authors, and with the predictions of unified models.

Nobuyuki Sakai, Jun&#39;ichi Yokoyama, Kei-ichi Maeda

According to previous work, topological defects expand exponentially without an end if the vacuum expectation value of the Higgs field is of the order of the Planck mass. We extend the study of inflating topological defects to the Brans-Dicke gravity. With the help of numerical simulation we investigate the dynamics and spacetime structure of a global monopo

Leo Radzihovsky, John Toner

We study smectic liquid crystals in random environments, e.g., aerogel. A low temperature analysis reveals that even arbitrarily weak quenched disorder (i.e., arbitrarily low aerogel density) destroys translational (smectic) order. A harmonic approximation to the elastic energy suggests that there is no ``smectic Bragg glass&#39;&#39; phase in this system: e

Soon-Tae Hong, Yong-Wan Kim, Young-Jai Park

In the framework of Dirac quantization, the SU(2) Skyrmion is canonically quantized to yield the modified predictions of the static properties of baryons. We show that the energy spectrum of this Skyrmion obtained by the Dirac method with the suggestion of generalized momenta is consistent with the result of the Batalin-Fradkin-Tyutin formalism.

Jeong-Man Park, Michael W. Deem

We analyze bimolecular reactions that proceed by a long-ranged reactive interaction, using a field theoretic approach that takes into account fluctuations. We consider both the one-species, $A+A \to \emptyset$ reaction and the two-species, $A+B \to \emptyset$ reaction. We consider both mobile and immobile reactants, both in the presence and in the absence of

O. Bergman

As a novel application of string junctions, we provide evidence for the existence of stable non-BPS dyons with magnetic charge greater than 1 in (the semiclassical regime of) N=2 SU(2) Super-Yang-Mills theory. In addition, we find a new curve of marginal stability. Moduli space is therefore divided into four regions, each containing a different stable partic

Raymond Y. Chiao

Experiments have shown that individual photons penetrate an optical tunnel barrier with an effective group velocity considerably greater than the vacuum speed of light. The experiments were conducted with a two-photon parametric down-conversion light source, which produced correlated, but random, emissions of photon pairs. The two photons of a given pair wer

Farhad Darabi

The issue of inertia as opposition to acceleration of a massive point particle in Minkowski space-time is investigated in the context of a Hamiltonian constraint system. It is shown that the inertia as a locally-originating force in Minkowski space-time may emerge due to a global constraint.

F. Bogomolov, Yu. Tschinkel

Let $V_1$ be the Fano threefold given as a hypersurface of degree 6 in $P(1,1,1,2,3)$ (over a number field $K$). Then there exists a finite extension $K&#39;/K$ such that the set of $K&#39;$-rational points of $X$ is Zariski dense.

William P. Ziemer, Kevin Zumbrun

For a given domain $Ω\subset \Bbb{R}^n$, we consider the variational problem of minimizing the $L^1$-norm of the gradient on $Ω$ of a function $u$ with prescribed continuous boundary values and satisfying a continuous lower obstacle condition $u\ge Ψ$ inside $Ω$. Under the assumption of strictly positive mean curvature of the boundary $\partialΩ$, we show ex

R. Milson

The present note considers a certain family of sums indexed by the set of fixed length compositions of a given number. The sums in question cannot be realized as weighted compositions. However they can be be related to the hypergeometric function, thereby allowing one to factorize the corresponding generating polynomials. This factorization leads to some int

Julian Dontchev

We answer a recent question of Pyrih by proving that a topological space $(X,τ)$ is open-normal if and only if it is extremally disconnected.

L. C. Garcia de Andrade

A propagation torsion model for quantized vortices is proposed.The model is applied to superfluids and liquid Helium II.

L. C. Garcia de Andrade

An example is given of a plane topological defect solution of linearized Einstein-Cartan (EC) field equation representing a cosmic wall boundary of spinning matter. The source of Cartan torsion is composed of two orthogonal lines of static polarized spins bounded by the cosmic plane wall. The Kopczyński- Obukhov - Tresguerres (KOT) spin fluid stress-energy c

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

A new treatment of Bose-Einstein correlations is incorporated in a space-time parton-shower model for e+ e- annihilation into hadrons. Two alternative afterburners are discussed, and we use a simple calculable model to demonstrate that they reproduce successfully the size of the hadron emission region. One of the afterburners is used to calculate two-pion co

Antonio Ferrera

The chain of events usually understood to lead to the formation of topological defects during phase transitions is known as the Kibble mechanism. A central component of the mechanism is the so-called ``geodesic rule&#39;&#39;. Although in the Abelian Higgs model the validity of the geodesic rule has been questioned recently, it is known to be valid on energe

A. V. Stepanova, F. V. Tkachov

We present an algebraic algorithm for analytical calculation of arbitrary dimensionally regulated massless two-loop forward-scattering diagrams that constitute the most cumbersome part of next-to-leading order calculations in the large-s/small-x regime.

A. N. Lavrov, M. Yu. Kameneva, L. P. Kozeeva

We have revealed new features in the out-of-plane resistivity rho_c of heavily underdoped RBa_2Cu_3O_{6+x} (R=Tm,Lu) single crystals, which give evidence for two distinct mechanisms contributing the c-axis transport. We have observed a crossover towards &#34;metal-like&#34; (d rho_c/d T > 0) behavior at the temperature T_m which quickly increases with decrea

J. H. Miller,, C. Ordonez, E. Prodan

A model is discussed in which an electric field induces quantum nucleation of soliton-antisoliton pairs in a pinned charge or spin density wave. Coulomb blockade prevents pair creation until the electric field exceeds a sharp threshold value, which can be much smaller than the classical depinning field. We calculate the vacuum state energy and expectation va

Chiranjeeb Buragohain, Subir Sachdev

We present a general theory for the intermediate temperature (T) properties of Heisenberg antiferromagnets of spin-S ions on p-leg ladders, valid for 2Sp even or odd. Following an earlier proposal for 2Sp even (Damle and Sachdev, cond-mat/9711014), we argue that an integrable, classical, continuum model of a fixed-length, 3-vector applies over an intermediat

C. Sivaram, L. C. Garcia de Andrade

The torsion modified Maxwell-Proca equations when applied to describe a plasma is shown to lead to a correction to the Debye screening length.For hot new born neutron stars the torsion correction is shown to be significant.This effect may provide an indirect evidence for Torsion.

Asantha R. Cooray, Jean M. Quashnock, M. Coleman Miller

We calculate the expected number of multiply-imaged galaxies in the Hubble Deep Field (HDF), using photometric redshift information for galaxies with m_I < 27 that were detected in all four HDF passbands. A comparison of these expectations with the observed number of strongly lensed galaxies constrains the current value of Omega_m-Omega_Lambda, where Omega_m

Willie Soon, Peter Frick, Sallie Baliunas

We explore subtle variations in disk-integrated measurements spanning $\lsim$ 18 years of stellar surface magnetism by using a newly developed time-frequency gapped wavelet algorithm. We present results based on analysis of the Mount Wilson Ca II H and K emission fluxes in four, magnetically-active stars (HD 1835 [G2V], 82885 [G8IV-V], 149661 [K0V] and 19000

Mallory S. E. Roberts, Roger W. Romani, Simon Johnston, Anne J. Green

We have mapped the radio emission in the error ellipse of GeV J1417-6100 (2EGS J1418-6049) at 13cm and 20cm using the Australia Telescope Compact Array. We find a large shell with extended wings, at the edge of which is a non-thermal, polarized structure with a center filled morphology (the `Rabbit&#39;), coincident with an extended, hard X-ray source. We di

V. Connaughton, C. R. Robinson, M. L. McCollough, S. A. Laurent-Muehleisen

The Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory has been shown to be sensitive to non-transient hard X-ray sources in our galaxy, down to flux levels of 100 mCrab for daily measurements, 3 mCrab for integrations over several years. We use the continuous BATSE database and the Earth Occultation technique to extract avera

Adrian Dragulescu, Victor M. Yakovenko, David J. Singh

Using the calculated electron energy band structure of Tl2Ba2CuO6, we compute the dependence of the c axis magnetoresistance on the orientation of the magnetic field for different magnitudes of the magnetic field. We explain the known experimental results for the in-plane rotation of the magnetic field and predict the shape of the magnetoresistance oscillati

Charles Rezk

We describe a category, the objects of which may be viewed as models for homotopy theories. We show that for such models, ``functors between two homotopy theories form a homotopy theory&#39;&#39;, or more precisely that the category of such models has a well-behaved internal hom-object.

S. L. Braunstein, C. M. Caves, R. Jozsa, N. Linden

We give a constructive proof that all mixed states of N qubits in a sufficiently small neighborhood of the maximally mixed state are separable. The construction provides an explicit representation of any such state as a mixture of product states. We give upper and lower bounds on the size of the neighborhood, which show that its extent decreases exponentiall

C. D. Froggatt, M. Gibson, H. B. Nielsen

A natural solution to the fermion mass hierarchy problem suggests the existence of a partially conserved chiral symmetry. We show that this can lead to a reasonably natural solution to the solar and atmospheric neutrino problems without fine-tuning or the addition of new low energy fermions. The atmospheric neutrino atmospheric neutrino anomaly is given by l

Benjamin Grinstein

Recent advances in lattice and continuum QCD have given us new insights into quarkonium physics. These set of lectures are intend for the uninitiated. We first give a physical picture of quarkonium and describe the hybrids states established in lattice QCD. Then we give an unorthodox presentation of Non-Relativistic QCD (NRQCD) including a novel method for t

Sergei M. Kopeikin

Pulsars are the most stable natural frequency standards. They can be applied to a number of principal problems of modern astronomy and time-keeping metrology. The full exploration of pulsar properties requires obtaining unbiased estimates of the spin and orbital parameters. These estimates depend essentially on the random noise component being revealed in th

Jens O. Andersen, Michael Strickland

A homogeneous Bose gas is investigated at finite temperature using renormalization group techniques. A non--perturbative flow equation for the effective potential is derived using sharp and smooth cutoff functions. Numerical solutions of these equations show that the system undergoes a second order phase transition in accordance with universality arguments.

R. Skip Garibaldi

It is well-known that every algebraic group of type F_4 is the automorphism group of an exceptional Jordan algebra, and that up to isogeny all groups of type ^1E_6 with trivial Tits algebras arise as the isometry groups of norm forms of such Jordan algebras. We describe a similar relationship between groups of type E_6 and groups of type E_7 and use it to gi

Per Bak, Simon F. Norrelykke, Martin Shubik

We present a dynamical many-body theory of money in which the value of money is a time dependent ``strategic variable&#39;&#39; that is chosen by the individual agents. The value of money in equilibrium is not fixed by the equations, and thus represents a continuous symmetry. The dynamics breaks this continuous symmetry by fixating the value of money at a le

C. Villagonzalo, R. A. Roemer

We investigate the behavior of the thermoelectric power [S] in disordered systems close to the Anderson-type metal-insulator transition [MIT] at low temperatures. In the literature, we find contradictory results for S. It is either argued to diverge or to remain a constant as the MIT is approached. To resolve this dilemma, we calculate the number density of

R. Lehoucq, Jean-Pierre Luminet, Jean-Philippe Uzan

Universe models with compact spatial sections smaller than the observable universe produce a topological lens effect. Given a catalog of cosmic sources, we estimate the number of topological images in locally hyperbolic and locally elliptic spaces, as a function of the cosmological parameters, of the volume of the spatial sections and of the catalog depth. N

Xi-Wen Guan, Uwe Grimm, Rudolf A. Roemer

Using a fermionic version of the Lax pair formulation, we construct an integrable small-polaron model with general open boundary conditions. The Lax pair and the boundary supermatrices $K_{\pm}$ for the model are obtained. This provides a direct proof of the integrability of the model.

Luis Craco, Kicheon Kang

Resonant tunnelling through an Anderson impurity is investigated by employing a new perturbation scheme at nonequilibrium. This new approach gives the correct weak and strong coupling limit in $U$ by introducing adjustable parameters in the self-energy and imposing self-consistency of the occupation number of the impurity. We have found that the zero-tempera

Paolo Salucci, Ewa Szuszkiewicz, Pierluigi Monaco, Luigi Danese

We derive the mass function of the relic black holes and compared with that of the Massive Dark Objects in galaxies. Under the assumption that accretion onto massive BH&#39;s powers the Active Galactic Nuclei, the mass function of the BH responsibile for the past activity of QSO/AGN is computed. Our results support the scenario in which the QSO phase has exc

Nobuyoshi Ohta, Jian-Ge Zhou

The greybody factors for spin 1/2 particles in the BTZ black holes are discussed from 2D CFT in bulk-boundary correspondence. It is found that the initial state of spin 1/2 particle in the BTZ black holes can be described by the Poincaré vacuum state in boundary 2D CFT, and the nonlinear coordinate transformation causes the thermalization of the Poincaré vac

Ben C. Buchler, Elanor H. Huntington, Timothy C. Ralph

Theoretical results are presented which show that noiseless phase quadrature amplification is possible, and limited experimentally only by the efficiency of the phase detection system. Experimental results obtained using a Nd:YAG laser show a signal gain of 10dB and a signal transfer ratio of T_s=0.9. This result easily exceeds the standard quantum limit for

Eric Sedgwick

Let M be a closed, irreducible, genus two 3-manifold, and F a maximal collection of pairwise disjoint, closed, orientable, incompressible surfaces embedded in M. Then each component manifold M_i of M-F has handle number at most one, i.e. admits a Heegaard splitting obtained by attaching a single 1-handle to one or two components of boundary M_i. This result

Ming-Hsien Tu, Jiin-Chang Shaw, Chin-Rong Lee

We study Darboux-Bäcklund transformations (DBTs) for the $q$-deformed Korteweg-de Vries hierarchy by using the $q$-deformed pseudodifferential operators. We identify the elementary DBTs which are triggered by the gauge operators constructed from the (adjoint) wave functions of the hierarchy. Iterating these elementary DBTs we obtain not only $q$-deformed Wro

Michael Fleischhauer

Resonant optical pumping in dense atomic media is discussed, where the absorption length is less than the smallest characteristic dimension of the sample. It is shown that reabsorption and multiple scattering of spontaneous photons (radiation trapping) can substantially slow down the rate of optical pumping. A very slow relaxation out of the target state of