September 1998 arXiv papers — page 9

Katsunori Wakabayashi, Mitsutaka Fujita, Hiroshi Ajiki, Manfred Sigrist

Electronic and magnetic properties of ribbon-shaped nanographite systems with zigzag and armchair edges in a magnetic field are investigated by using a tight binding model. One of the most remarkable features of these systems is the appearance of edge states, strongly localized near zigzag edges. The edge state in magnetic field, generating a rational fracti

Sameen Ahmed Khan

General guidelines for constructing a quantum theory of charged-particle beam optics starting ab initio from the basic equations of quantum mechanics, appropriate to the situation under study. In the context of spin-1/2 particles, these guidelines are used starting with the Dirac equation. The spinor theory just constructed is used to obtain the transfer map

Jesse Hersch, Eric Heller

We have observed proximity resonances in a two dimensional system consisting of dielectric scatterers in a parallel plate waveguide. A numerical solution to the scattering problem supports the analysis of the experimental data.

P. D. Jarvis, J. D. Bashford

Important aspects of the process of information storage and retrieval in DNA and RNA, and its evolution, are the role of the anticodons and associated $t$RNA's, and correlations between anticodons and amino acids; the degeneracy of the genetic code, and the periodicity of many amino acid physico-chemical properties. Such factors are analysed in the conte

E. M. Henley, W-Y. P. Hwang, L. S. Kisslinger

We have made a needed correction to our earlier paper (nucl-th/9511002), which contains a sign error. With this correction, the weak parity-violating pion-nucleon coupling is about 3 x 10^(-7).

H. A. Weidenmueller, P. von Brentano, B. R. Barrett

The attenuation factor F responsible for the decay out of a superdeformed (SD) band is calculated with the help of a statistical model. This factor is given by 1/F = (1 + Gamma(down) / Gamma(S)). Here, Gamma(S) is the width for the collective E2 transition within the superdeformed band, and Gamma(down) is the spreading width which describes the mixing betwee

Piotr M. Hajac

This article is a follow-up of ``Holonomy and Path Structures in General Relativity and Yang-Mills Theory" by Barrett, J. W. (Int.J.Theor.Phys., vol.30, No.9, 1991). Its main goal is to provide an alternative proof of this part of the reconstruction theorem which concerns the existence of a connection. A construction of connection 1-form is presented. Th

Boris Shoikhet

It is proved that the associative differential graded algebra of (polynomial) polyvector fields on a vector space (may be infinite- dimensional) is quasi-isomorphic to the corresponding cohomological Hochschild complex of (polynomial) functions on this vector space as an associative differential graded algebra. This result is an $A_\infty$-version of the For

Michel Van den Bergh

In this paper we will think of certain abelian categories with favorable properties as non-commutative surfaces. We show that under certain conditions a point on a non-commutative surface can be blown up. This yields a new non-commutative surface which is in a certain sense birational to the original one. This construction is analogous to blowing up a Poisso

Donald A. Dawson, Klaus Fleischmann, Carl Mueller

Consider a catalytic super-Brownian motion $X=X^Γ$ with finite variance branching. Here `catalytic&#39; means that branching of the reactant $X$ is only possible in the presence of some catalyst. Our intrinsic example of a catalyst is a stable random measure $Γ$ on $R$ of index $0< gamma <1$. Consequently, here the catalyst is located in a countable dense su

Jozef H. Przytycki

Skein modules are the main objects of an algebraic topology based on knots (or position). In the same spirit as Leibniz we would call our approach &#34;algebra situs.&#34; When looking at the panorama of skein modules we see, past the rolling hills of homologies and homotopies, distant mountains - the Kauffman bracket skein module, and farther off in the dis

U. D. Jentschura, P. J. Mohr, G. Soff, E. J. Weniger

A method of numerically evaluating slowly convergent monotone series is described. First, we apply a condensation transformation due to Van Wijngaarden to the original series. This transforms the original monotone series into an alternating series. In the second step, the convergence of the transformed series is accelerated with the help of suitable nonlinea

S. Deser, Orit Levin

By globally embedding curved spaces into higher dimensional flat ones, we show that Hawking thermal properties map into their Unruh equivalents: The relevant curved space detectors become Rindler ones, whose temperature and entropy reproduce the originals. Specific illustrations include Schwarzschild, Schwarzschild-(anti)deSitter, Reissner-Nordstrom and BTZ

G. W. Gibbons, P. Rychenkova

In this note we show that rigid N=2 superconformal hypermultiplets must have target manifolds which are cones over tri-Sasakian metrics. We comment on the relation of this work to cone-branes and the AdS/CFT correspondence.

Alfred Davis, Tristan Hubsch

A fermionic analogue of the Hodge star operation is shown to have an explicit operator representation in models with fermions, in spacetimes of any dimension. This operator realizes a conjugation (pairing) not used explicitly in field-theory, and induces a metric in the space of wave-function(al)s just as in exterior calculus. If made real (Hermitian), this

Andrzej Trautman

This paper reviews some recent work on (s)pin structures and the Dirac operator on hypersurfaces (in particular, on spheres), on real projective spaces and quadrics. Two approaches to spinor fields on manifolds are compared. The action of space and time reflections on spinors is discussed, also for two-component (chiral) spinors.

V. Aldaya, M. Calixto, J. M. Cervero

Although the whole conformal group $SO(4,2)$ can be considered as a symmetry in a classical massless field theory, the subgroup of special conformal transformations (SCT), usually related to transitions to uniformly accelerated frames, causes vacuum radiation in the corresponding quantum field theory, in analogy to the Fulling-Unruh effect. The spectrum of t

Adrian Patrascioiu, Erhard Seiler

We report the results of a very high statistics Monte Carlo study of the continuum limit of the two dimensional O(3) non-linear $σ$ model. We find a significant discrepancy between the continuum extrapolation of our data and the form factor prediction of Balog and Niedermaier, inspired by the Zamolodchikovs&#39; S-matrix ansatz. On the other hand our results

S. Deser, J. McCarthy, O. Sarioglu

We present some consequences of non-anomalous propagation requirements on various massless fields. Among the models of nonlinear electrodynamics we show that only Maxwell and Born-Infeld also obey duality invariance. Separately we show that, for actions depending only on the $F_\mn^2$ invariant, the permitted models have $L \sim \sqrt{1 + F^2}$. We also char

B. Sazdovic

We find the general solution of the equations of motion for the WZNW system in curved space-time for arbitrary external gauge fields. Using the connection between the WZNW system for $SL(2,R)$ group and 2D induced gravity we obtain the general solution of the equations of motion for 2D induced gravity in curved space-time from that of the WZNW system. We ind

M. Blagojevic, B. Sazdovic

We introduce a consistent gauge extension of the SL(2,R) WZNW system, defined by a difference of two simple WZNW actions. By integrating out some dynamical variables in the functional integral, we show that the resulting effective theory coincides with the induced gravity in 2D. General solutions of both theories are found and related to each other.

Ali H. Chamseddine

The definition of the spectral action involves the trace operator over states in the physical Hilbert space. We show that in the presence of chiral fermions there are consistency conditions on the fermionic representations. These conditions are identical to the conditions for absence of gauge and gravitational anomalies obtained in the path integral formalis

T. S. T. Aly, J. A. McNeil

We revisit the work of K. Goeke, M. Harvey, F. Grümmer, and J. N. Urbano (Phys. Rev. {\bf D37}, 754 (1988)) who considered a chiral model for the nucleon based on the linear sigma model with scalar-isoscalar scalar-isovector mesons coupled to quarks and solved using the coherent-pair approximation. In this way the quantum pion field can be treated in a non-p

Iain Bertram, Elizabeth H. Simmons

Using recent D0 data on the dijet mass spectrum, we present a limit on flavor-universal colorons. At 95% CL we find Mc/cot(theta) > 837 GeV. We discuss the implications of this limit for models of quark compositeness, non-standard gluon interactions, and dynamical electroweak symmetry breaking. In addition, we place a lower bound Lambda_A8 > 2.1 TeV on the s

C. Greub, T. Hurth

We report recent theoretical progress in the analysis of radiative corrections in inclusive rare B-decays. In view of the B-factories, currently under construction at SLAC and KEK, and of the upgraded CESR experiment, the experimental status of rare B decays is expected to improve significantly in the near future. We review the complete NLL QCD calculations

Steven Abel, Stephen King

We examine the fixed point behaviour of Yukawa couplings in supersymmetric theories with varying numbers of dimensions. We show that Pendleton-Ross fixed point behaviour is greatly amplified in the MSSM with no extra dimensions and 4 extra $5+\bar{5}$ multiplets or the MSSM with one extra large dimension and 3 extra $5+\bar{5}$ multiplets. We also show that

S. M. Bilenky, C. Giunti, W. Grimus, T. Schwetz

We investigate the implications of the standard Big-Bang Nucleosynthesis constraint on the number of light neutrinos in the framework of the two four-neutrino schemes that are favored by the results of neutrino oscillation experiments.

G. S. Sharov

Rotational motions for the quark-diquark (q-qq), linear (q-q-q) &#34;three-string&#34; (Y) and &#34;triangle&#34; string baryon models are considered and applied to description of baryonic orbitally exited states on the Regge trajectories. For the model &#34;triangle&#34; (three pointlike masses bounded pairwise by relativistic strings) the rotating closed s

J. L. Chkareuli

A new superstring-motivated framework for a treatment of SU(N) SUSY GUTs is argued. We show that all the present difficulties of the minimal supersymmetric SU(5) model can successfully be overcome with a new renormalizable reflection-invariant superpotential with two-adjoint scalars, one of which is interpreted as a massive string mode essentially decoupled

G. Wilk, Z. Wlodarczyk

We argue that the so called long flying component (LFC) observed in some cosmic ray experiments are yet another manifestation of Lévy distributions (with index $q=1.3$), this time of the distribution observation probability of the depths of starting points of cascades. It means that LFC is governed by the so called long-tail Lévy-like anomalous superdiffusio

G. Wilk, Z. Wlodarczyk

The inelasticity of hadron-carbon collisions for energies exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs to be $<K_C> = 0.65\pm 0.08$. When combined with data on hadron-lead collisions taken at the same energy range it results in the $K\sim A^{0.086}$ mass number dependence of inelasticity. The evaluated partial inelasticity f

C. Greiner, Z. Xu, T. S. Biro

Applying a Langevin description of the linear sigma model we investigate four different scenarios for the evolution of a disoriented chiral condensate: annealing or quench with initial conditions governed by effective `light&#39; or physical mass pions. We present pion number distributions estimated from the zero mode (i.e. k=0-field) component. The best DCC

N. Brambilla, A. Vairo

We report about recent progress in the treatment of bound states in QCD.

Anton Rebhan

The convergence properties of the resummed thermal perturbation series for the thermodynamic pressure are investigated by comparison with the exact results obtained in large-N phi^4 theory and possibilities for improvements are discussed. By going beyond conventional resummed perturbation theory, renormalization has to be carried out nonperturbatively yet co

G. Arnold, Th. Lippert, K. Schilling

We demonstrate that substantial progress can be achieved in the study of the phase structure of 4-dimensional compact QED by a joint use of hybrid Monte Carlo and multicanonical algorithms, through an efficient parallel implementation. This is borne out by the observation of considerable speedup of tunnelling between the metastable states, close to the phase

P. Chen, N. Christ, G. Fleming, A. Kaehler

We present results from numerical simulations of full, two flavor QCD thermodynamics at N_t=4 with domain wall fermions. For the first time a numerical simulation of the full QCD phase transition displays a low temperature phase with spontaneous chiral symmetry breaking but intact flavor symmetry and a high temperature phase with the full SU(2) x SU(2) chira

M. N. Chernodub, M. I. Polikarpov, A. I. Veselov, M. A. Zubkov

SU(2) gluodynamics is investigated numerically and analytically in the (Indirect) Maximal Center gauge at finite temperature. The center vortices are shown to be condensed in the confinement phase and dilute in the deconfinement phase. A new physical object, center monopole, is constructed. We show that the center monopole condensate is the order parameter o

G. Peter Lepage

We resolve contradictions in the literature concerning the origins and size of unphysical flavor-changing strong interactions generated by the staggered-quark discretization of QCD. We show that the leading contributions are tree-level in $\order(a^2)$ and that they can be removed by adding three correction terms to the link operator in the standard action.

N. Yamada, S. Hashimoto, K-I. Ishikawa, H. Matsufuru

We present the preliminary result of the calculation of $B_B$ parameter using lattice NRQCD. The calculation is performed on a $16^3 \times 48$ quenched lattice at $β=5.9$ with clover light quark. The use of lattice NRQCD enables us to investigate the $1/m_Q$ correction from the static limit. The observed mass dependence is well described by the vacuum satur

S. Thurner, H. Markum, E. -M. Ilgenfritz, M. Müller-Preussker

Using a renormalization group motivated smoothing technique, we investigate the large scale structure of lattice configurations at finite temperature, concentrating on Abelian monopoles identified in the maximally Abelian, the Laplacian Abelian, and the Polyakov gauge. Monopoles are mostly found in regions of large action and topological charge, rather indep

K. Cahill, G. Herling

The positive-plaquette Manton action at weak coupling is a reasonable action for short-distance phenomena. We propose an iterative scheme for evolving this action into an effective action for longer distance scales. We report on the first step of this scheme in which we have measured ``blocked&#39;&#39; Creutz ratios with lattice spacing 2a at beta = 16 on a

R. Aldrovandi, J. G. Pereira

Solutions of the sourceless Einstein&#39;s equation with weak and strong cosmological constants are discussed by using Inönü-Wigner contractions of the de Sitter groups and spaces. The more usual case corresponds to a weak cosmological-constant limit, in which the de Sitter groups are contracted to the Poincaré group, and the de Sitter spaces are reduced to

Nicola A. Hill, Karin M. Rabe

We present results of local spin density approximation (LSDA) pseudopotential calculations for the perovskite structure oxide, bismuth manganite (BiMnO3). The origin of the differences between bismuth manganite and other perovskite manganites is determined by first calculating total energies and band structures of the high symmetry cubic phase, then sequenti

A. L. Malvezzi, S. Yunoki, E. Dagotto

The influence of a nearest-neighbor Coulomb repulsion of strength V on the properties of the Ferromagnetic Kondo model is analyzed using computational techniques. The Hamiltonian studied here is defined on a chain using localized S=1/2 spins, and one orbital per site. Special emphasis is given to the influence of the Coulomb repulsion on the regions of phase

J. Boutet de Monvel

The Longest Common Subsequence (LCS) Problem asks for the longest sequence of (non-contiguous) matches between two given strings of characters. Using extensive Monte Carlo simulations, we find a finite size scaling law of the form E(L)/N =C + A/(N^1/2 ln N)+... for the mean LCS length of two random strings of size N over S letters. We provide precise estimat

J. Kent Harbaugh, D. Stroud

We calculate the current-voltage characteristics and critical current I_c^{array} of an array of Josephson-coupled superconducting wires. The array has two layers, each consisting of a set of parallel wires, arranged at right angles, such that an overdamped resistively-shunted junction forms wherever two wires cross. A uniform magnetic field equal to f flux

Michele Cini, Gianluca Stefanucci, Adalberto Balzarotti

We calculate the effective interaction $W_{eff}$ between two holes added to the ground state of the repulsive three-band Hubbard model. To make contact with Cooper theory and with earlier Hubbard model cluster studies, we first use a perturbative canonical transformation, to generate a two-body Hamiltonian. Then, we extend the results to all orders. The appr

Imre Derenyi, Tamas Vicsek

We consider the collective motion of finite-sized, overdamped Brownian particles (e.g., motor proteins) in a periodic potential. Simulations of our model have revealed a number of novel cooperative transport phenomena, including (i) the reversal of direction of the net current as the particle density is increased and (ii) a very strong and complex dependence

Z. Pluhar, H. A. Weidenmueller

We complement a recent calculation (P.B. Gossiaux and the present authors, Ann. Phys. (N.Y.) in press) of the autocorrelation function of the conductance versus magnetic field strength for ballistic electron transport through microstructures with the shape of a classically chaotic billiard coupled to ideal leads. The function depends on the total number M of

I. C. Charret, E. V. Corrêa Silva, S. M. de Souza, O. Rojas Santos

For any d-dimensional self-interacting fermionic model, all coefficients in the high-temperature expansion of its grand canonical partition function can be put in terms of multivariable Grassmann integrals. A new approach to calculate such coefficients, based on direct exploitation of the grassmannian nature of fermionic operators, is presented. We apply the

L. R. Evangelista, S. Fontanini, L. C. Malacarne, R. S. Mendes

The contribution of the smectic-nematic interface to the surface energy of a nematic liquid crystal sample is analyzed. By means of a simple model it is shown that the surface energy depends on the thickness of the region over which the transition smectic-nematic takes place. For perfectly flat substrates this thickness is of the order of the correlation len

C. P. Heij, D. C. Dixon, P. Hadley, J. E. Mooij

We present the multilevel fabrication and measurement of a Coulomb-blockade device displaying tunable negative differential resistance (NDR). Applications for devices displaying NDR include amplification, logic, and memory circuits. Our device consists of two Al/Al$_{x}$O$_{y}$ islands that are strongly coupled by an overlap capacitor. Our measurements agree

P. Ao

There has been a corporative absence of understanding of Hall anomaly data in the mixed state in terms of vortex many-body effect and pinning, because of the dominant theoretical influence. Now D&#39;Anna et al. [ Phys. Rev. Lett. 81, 2530 (1998) (cond-mat/9808164)] are brave enough to announce the prominent role played by vortex many-body effect and pinning

G. Akemann, G. M. Cicuta, L. Molinari, G. Vernizzi

We consider a generalization of the fixed and bounded trace ensembles introduced by Bronk and Rosenzweig up to an arbitrary polynomial potential. In the large-N limit we prove that the two are equivalent and that their eigenvalue distribution coincides with that of the &#34;canonical&#34; ensemble with measure exp[-$n$Tr V(M)]. The mapping of the correspondi

Kwan-tai Leung, Zoltan Neda

The kinetic Ising model in a weak oscillating magnetic field is studied in the context of stochastic resonance. The signal-to-noise ratio calculated with simulations is found to peak at a nontrivial resonance temperature above the equilibrium critical temperature T_c. We argue that its appearance is closely related to the vanishing of the kinetic coefficient

Walter Kob

After a brief introduction to the dynamics of supercooled liquids, we discuss some of the advantages and drawbacks of computer simulations of such systems. Subsequently we present the results of computer simulations in which the dynamics of a fragile glass former, a binary Lennard-Jones system, is compared to the one of a strong glass former, SiO_2. This com

K. Lejnell, A. Karlhede, S. L. Sondhi

We report on analytic and numerical studies of spin textures in quantum Hall systems using a long-wavelength effective action for the magnetic degrees of freedom derived previously. The majority of our results concern skyrmions or solitons of this action. We have constructed approximate analytic solutions for skyrmions of arbitrary topological and electric c

Hiroshi Kuratsuji, Shouhei Kakigi

A theoretical study is given of a new type of optical vortex in nonlinear anisotropic media. This is called an ``optical spin vortex&#39;&#39;, which is realized as a special solution of the two-component non-linear Schrödinger equation. The existence of spin vortex is inherent in the spin texture that is caused by the anisotropy of dielectric tensor, where

K. -V. Pham, M. Gabay, P. Lederer

In this paper, we present a description of Haldane&#39;s Luttinger liquid which parallels Laughlin&#39;s theory of the Fractional Quantum Hall (FQH) incompressible fluid, both exhibiting similar ground states as well as fractional excitations. These two non-Fermi liquids are instances of a generic structure for low-dimensional quantum liquids which we propos

M. A. Pahre, J. R. Mould, A. Dressler, the WFPC-2 Investigation Definition Team

Surface brightness fluctuations (SBF) have been detected for three elliptical galaxies-NGC 3379 in the Leo group, NGC 4406 in the Virgo cluster, and NGC 4373 in the Hydra-Centaurus supercluster-using marginally-sampled, deep images taken with the Planetary Camera of the WFPC-2 instrument on the Hubble Space Telescope (HST). The power spectrum of the fluctuat

Andrei Gruzinov

The rate of turbulent spherical accretion onto a compact object might be much smaller than the Bondi rate. It is suggested that the rate of accretion onto Sgr A-star is much smaller than the Bondi rate.

E. Chereul, M. Crézé, O. Bienaymé

A volume limited and absolute magnitude limited sample of A-F type dwarfs within 125 parsecs of the Sun is searched for inhomogeneities in the density- velocity space, expecting signatures of the cluster evaporation, phase mixing and possible disc heating mechanisms. A 3-D wavelet analysis is used to extract inhomogeneities, both in the density and velocity

Mordecai-Mark Mac Low

The physical basis for interpreting observations of nebular morphology around massive stars in terms of the evolution of the central stars is reviewed, and examples are discussed, including NGC 6888, OMC-1, and eta Carinae.

D. Thomas, L. Greggio, R. Bender

We explore the formation of alpha-enhanced and metal-rich stellar populations in the nuclei of luminous ellipticals under the assumption of two extreme galaxy formation scenarios based on hierarchical clustering, namely a fast clumpy collapse and the merger of two spirals. We investigate the parameter space of star formation time-scale, IMF slope, and stella

Sylvie Vauclair, Olivier Richard

Improvements induced by helioseismology show that microscopic diffusion cannot be neglected in solar models. Helium and metal diffusion is now generally introduced in the computations. They cannot however explain the observed lithium depletion. Macroscopic motions are needed to bring up to the convection zone the nuclearly depleted matter. Such motions also

E. Giallongo, A. Fontana, S. Cristiani, S. D&#39;Odorico

The quasar Q1208+1011 (z_{em}=3.8) is the second highest redshift double quasar ever detected. Several indications point toward it being a gravitational lensed system, although a definitive proof is still lacking. We present new evidence of its lensed nature based on the weakness of the ``proximity effect&#39;&#39; measured in the high resolution Lyman absor

Werner M. Vieira, Patricio S. Letelier

We make a detailed analysis of Newtonian as well as relativistic core-shell models recently proposed to describe a black hole or neutron star surrounded by shells of matter, and in a seminal sense also galaxies, supernovae and star remnants since there are massive shell-like structures surrounding many of them and also evidences for many galactic nuclei hidi

M. Persic, S. Mariani, M. Cappi, L. Bassani

We present BeppoSAX results on the nearby starburst galaxy NGC 253. Although extended, a large fraction of the X-ray emission comes from the nuclear region. Preliminary analysis of the LECS/MECS/PDS ~0.2-60 keV data from the central 4&#39; region indicates that the continuum is well fitted by two thermal models: a ``soft&#39;&#39; component with kT ~ 0.9 keV

Alexander Knebe, Volker Mueller

The formation, inner properties, and spatial distribution of galaxy groups and clusters are closely related to the background cosmological model. We use numerical simulations of variants of the CDM model with different cosmological parameters and distinguish relaxed objects from recent mergers using the degree of virialisation. Mergers occur mostly in deep p

M. Marconi, F. Palla

We investigate the pulsational properties of Pre--Main-Sequence (PMS) stars by means of linear and nonlinear calculations. The equilibrium models were taken from models evolved from the protostellar birthline to the ZAMS for masses in the range 1 to 4 solar masses. The nonlinear analysis allows us to define the instability strip of PMS stars in the HR diagra

Willy Kley

We study the structure and dynamics of the gap created by a protoplanet in an accretion disc. The hydrodynamic equations for a flat, two-dimensional, non-selfgravitating protostellar accretion disc with an embedded, Jupiter sized protoplanet on a circular orbit are solved. To simulate possible accretion of mass onto the protoplanet we continually remove mass

Yoshiaki Taniguchi, Youichi Ohyama

It is known that the class of luminous starburst galaxies tends to have higher $R =^{12}CO(J=1--0)/^{13}CO(J=1--0)$ integrated line intensity ratios ($R>20$) than normal spiral galaxies ($R \sim 10$). Since most previous studies investigated only $R$, it remains uncertain whether the luminous starburst galaxies are overabundant in $^{12}$CO or underabundant

L. H. Huang, D. R. Jiang, Xinwu Cao

We present a correlation analysis between the flux ratio of high-energy gamma-ray emission to synchrotron emission and the Doppler factor for a sample of EGRET AGNs. The results favor a model that attributes the EGRET emission of AGNs to inverse-Compton scattering on photons external to the jet.

Priyamvada Natarajan

We show that the luminosity function of the actively star-forming Lyman break galaxies and the B-band quasar luminosity function at $z = 3$ can be fit reasonably well with the mass function of collapsed galaxy scale dark matter haloes predicted by viable variants of hierarchical cold dark matter dominated cosmological models for lifetimes $t_Q$ of the optica

V. T. Ayvazyan

The identification of IRAS sources with Faint Markarian galaxies on the base of the Second Byurakan Survey were made. It is shown that about 30% of SBS galaxies are also IRAS sources.The list of newly identified objects are presented.

L. H. Huang, D. R. Jiang, Xinwu Cao

After comparing the flux densities of a sample of active galactic nuclei detected by energetic gamma-ray experiment telescope at 90 and 230 GHz with the $γ$-ray emissions detected by Compton Gamma Ray Observatory and x-ray emission, a strong correlation between the emissions at the millimeter wavelength and the $γ$-ray emission is found. The average flux den

F. Abe

We have used 87 pb^-1 of data collected with the Collider Detector at Fermilab to search for new particles decaying to b bbar. We present model-independent upper limits on the cross section for narrow resonances which excludes the color-octet technirho in the mass interval 350 < M < 440 GeV/c^2. In addition, we exclude topgluons, predicted in models of topco

Jerome Benoit, Rossen Dandoloff

Classical Heisenberg spins in the continuum limit (i.e. the nonlinear sigma-model) are studied on an elastic torus section with homogeneous boundary conditions. The corresponding rigid model exhibits topological soliton configurations with geometrical frustration due to the torus eccentricity. Assuming small and smooth deformations allows to find shapes of t

Roger Ellman

In March 2008 anomalous behavior in spacecraft flybys of Earth was reported in Physical Review Letters, Volume 100, Issue 9, March 7, 2008, in an article entitled &#34;Anomalous Orbital-Energy Changes Observed during Spacecraft Flybys of Earth&#34;. The data indicate unaccounted for changes in spacecraft speed, both increases and decreases, for six different

Alexander Braverman, David Kazhdan

Let G be the group of points of a split reductive algebraic group over a local field k and let X=G/U where U is a maximal unipotent subgroup of G. In this paper we construct certain canonical G-invariant space S(X) (called the Schwartz space of X) of functions on X, which is an extension of the space of smooth compactly supported functions on X. We show that

B. Galvan

Quantum mechanics states that a particle emitted at point (x_1,t_1) and detected at point (x_2,t_2) does not travel along a definite path between the two points. This conclusion arises essentially from the analysis of the two-slit experiment, which implicitly assumes (as in the demonstration of the EPR paradox) that a property we will call Independence Prope

Vadim Zharnitsky, Igor Mitkov, Niels Grønbech-Jensen

We demonstrate that $π$-kinks exist in non-parametrically ac driven sine-Gordon systems if the ac drive is sufficiently fast. It is found that, at a critical value of the drive amplitude, there are two stable and two unstable equilibria in the sine-Gordon phase. The pairwise symmetry of these equilibria implies the existence of a one-parameter family of $π$-

A. E. Kozhekin, G. Kurizki, Boris A. Malomed

We present hitherto unknown forms of soliton dynamics in the forbidden frequency gap of a Bragg reflector, modified by periodic layers of near-resonant two-level systems (TLS). Remarkably, even extremely low TLS densities create an allowed band within the forbidden gap. This spectrum gives rise, for any Bragg reflectivity, to a vast family of stable gap soli

Vadim Zharnitsky, Igor Mitkov, Mark Levi

A parametrically forced sine-Gordon equation with a fast periodic {\em mean-zero} forcing is considered. It is shown that $π$-kinks represent a class of solitary-wave solutions of the equation. This result is applied to quasi-one-dimensional ferromagnets with an easy plane anisotropy, in a rapidly oscillating magnetic field. In this case the $π$-kink solutio

S P Corney, P D Jarvis, D S McAnally

The exceptional superalgebra $D(2,1;α)$ has been classified as a candidate conformal supersymmetry algebra in two dimensions. We propose an alternative interpretation of it as extended BFV-BRST quantisation superalgebras in 2D ($D(2,1;1) \simeq osp(2,2|2)$). A superfield realization is presented wherein the standard extended phase space coordinates can be id

P. Ramond

We review the known ways of incorporating and breaking symmetries in a renormalizable way. We summarize the various grand unified theories based on $SU_5, SO_{10}$, and $E_6$ as family enlargement groups. An $SU_5$ model with an $SU_2$ gauged family group is presented as an illustration. In it, the e-family (i.e., e,u and d) is classically massless and acqui

R. Foot, C. N. Leung, O. Yasuda

Recent Super-Kamiokande data on the atmospheric neutrino anomaly are used to test various mechanisms for neutrino oscillations. It is found that the current atmospheric neutrino data alone cannot rule out any particular mechanism. Future long-baseline experiments should play an important role in identifying the underlying neutrino oscillation mechanism.

Harald Markum, Wolfgang Sakuler, Stefan Thurner

We study the topological and fermionic vacuum structure of four-dimensional QCD on the lattice by means of correlators of fermionic observables and topological densities. We show the existence of strong local correlations between the topological charge density and the quark condensate, charge and chiral density. By analysis of individual gauge configurations

E. -M. Ilgenfritz, H. Markum, M. Müller-Preussker, S. Thurner

Using the renormalization group motivated smoothing technique, the large scale structure of lattice configurations at finite temperature is characterized in terms of Abelian monopoles identified in the maximally Abelian, the Laplacian Abelian, and the Polyakov gauge. Abundance and anisotropy of monopoles at deconfinement and gauge invariant properties like l

JLQCD Collaboration, K-I. Ishikawa, N. Yamada, S. Aoki

We investigate the scaling behavior of the $B$ meson decay constant $f_B$ and $f_{B_{s}}$ at $β$$=$$5.7, 5.9, 6.1$, employing the NRQCD heavy quark action and the clover light quark action. Mixing effect from dimension-4 operator in the heavy-light axial-vector current is studied, and we find that the $a$ dependence of $f_B$ is significantly reduced. Our pre

JLQCD Collaboration, N. Tsutsui, S. Aoki, M. Fukugita

We report preliminary results of our study of matrix elements of baryon number violating operators which appear in the low-energy effective Lagrangian of (SUSY-)Grand Unified Theories. The calculation is performed on a $32^{3}\times80$ lattice at $β=6.1$ using Wilson fermions in the quenched approximation. Our calculation is independent of details of (SUSY-)

P. Stanski, S. Giles, A. Zaslavsky

With the increasing use of mobile workstations for a wide variety of tasks and associated information needs, and with many variations of available networks, access to data becomes a prime consideration. This paper discusses issues of workstation mobility and proposes a solution wherein the data structures are accessed in an encapsulated form - through the Po

J. Berg, A. Engel

Matrix games constitute a fundamental problem of game theory and describe a situation of two players with completely conflicting interests. We show how methods from statistical mechanics can be used to investigate the statistical properties of optimal mixed strategies of large matrix games with random payoff matrices and derive analytical expressions for the

E. Nogueira, S. Coutinho, F. D. Nobre, E. M. F. Curado

The critical properties of short-range Ising spin-glass models, defined on a diamond hierarchical lattice of graph fractal dimension $d_{f}=2.58$, 3, and 4, and scaling factor 2 are studied via a method based on the Migdal-Kadanoff renormalization-group scheme. The order parameter critical exponent $β$ is directly estimated from the data of the local Edwards

Joseph C. Shields, Richard W. Pogge, Michael M. De Robertis

Emission lines that trace elements subject to strong depletion onto grains provide a means for probing the dust content of AGNs. Examples include infrared [FeII] and optical [CaII] lines. The excitation mechanisms underlying the [FeII] lines remain controversial, resulting in related disagreement over the gas-phase abundance of iron in Seyfert narrow-line re

Edwin A. Bergin, Rene Plume, Jonathan P. Williams, Philip C. Myers

We present an observational and theoretical study of the ionization fraction in several massive cores located in regions that are currently forming stellar clusters. Maps of the emission from the J = 1-> O transitions of C18O, DCO+, N2H+, and H13CO+, as well as the J = 2 -> 1 and J = 3 -> 2 transitions of CS, were obtained for each core. Core densities are d

H. N. Nuñez-Yepez, E. Guillaumin-España, A. Gonzalez-Villanueva, R. P. Martinez y Romero

The hodograph of the Kepler-Coulomb problem, that is, the path traced by its velocity vector, is shown to be a circle and then it is used to investigate other properties of the motion. We obtain the configuration space orbits of the problem starting from initial conditions given using nothing more than the methods of synthetic geometry so close to Newton&#39

Marco M. Caldarelli

We investigate the propagation of arbitrarily coupled scalar fields on the $N$-dimensional hyperbolic space ${\mathbb H}^N$. Using the $ζ$-function regularization we compute exactly the one loop effective action. The vacuum expectation value of quadratic field fluctuations and the one loop renormalized stress tensor are then computed using the recently propo

C. Cisneros, R. P. Martínez-y-Romero, H. N. Nuñez-Yepez, A. L. Salas-Brito

The superposition principle is a very basic ingredient of quantum theory. What may come as a surprise to many students, and even to many practitioners of the quantum craft, is tha superposition has limitations imposed by certain requirements of the theory. The discussion of such limitations arising from the so-called superselection rules is the main purpose

Lorenza Viola, Seth Lloyd

We explore a strategy for protecting the evolution of a qubit against the effects of environmental noise based on the application of controlled time-dependent perturbations. In the case of a purely decohering coupling, an explicit sequence of control operations is designed, able to average out the decoherence of the qubit with high efficiency. We argue that,