May 2000 arXiv papers — page 11

Duncan R. Lorimer, Kiriaki M. Xilouris

We have extensively searched for periodic signals from the soft-gamma repeater SGR 1900+14, at 430 and 1410 MHz with the Arecibo telescope. Our observations did not reveal the 5.16-s periodicity discovered at X-ray wavelengths by Hurley et al. (1998). We place pulsed flux-density upper limits of 150 and 30 uJy at 430 and 1410 MHz respectively. In the course

Scott W. Chambers, Adrian L. Melott, Christopher J. Miller

We have examined whether the major axes of rich galaxy clusters tend to point toward their nearest neighboring cluster. We have used the data of Ulmer, McMillan, and Kowalski, who used position angles based on X-ray morphology. We also studied a subset of this sample with updated positions and distances from the MX Northern Abell Cluster Survey (for rich clu

Caslav Brukner, Anton Zeilinger

A new measure of information in quantum mechanics is proposed which takes into account that for quantum systems the only feature known before an experiment is performed are the probabilities for various events to occur. The sum of the individual measures of information for mutually complementary observations is invariant under the choice of the particular se

M. Genovese, C. Novero

We discuss the possibility of generating and detecting, by a tomographic reconstruction of the Wigner function, a macroscopic superposition of two coherent states. The superposition state is created using a conditioned measurement on the polarisation of a probe photon entangled to a coherent state. The entanglement is obtained using a Kerr cell inserted in a

T. Ya. Popova, A. K. Popov, S. G. Rautian, A. A. Feoktistov

The frequency correlation properties of the radiation from an atom in a strong field in resonance with neighboring transitions are considered. It is shown that the difference in frequency correlation in two-photon and stepwise processes decreases with increase of the external field. The spectral compositions of the Doppler-broadened resonance scattering and

Yair Guttmann, Holger Lyre

We propose a distinction between the physical and the mathematical parts of gauge field theories. The main problem we face is to uphold a strong and meaningful criterion of what is physical. We like to call it "Field's dilemma", referring to Hartry Field's nominalist proposal which we consider to be inadaequate. The resolution to the dilemma,

M. B. Barbaro, A. Molinari, F. Palumbo, M. R. Quaglia

The problem of the pairing interaction is dealt with even Grassmann variables in the hamiltonian framework. Eigenfunctions of given energy, seniority and zero third component of angular momentum are given in terms of single particle and collective bosonic fields.

Ernesto M. Nicola, Michal Or-Guil, Wilfried Wolf, Markus Baer

Drifting pattern domains (DPDs), moving localized patches of traveling waves embedded in a stationary (Turing) pattern background and vice versa, are observed in simulations of a reaction-diffusion model with nonlocal coupling. Within this model, a region of bistability between Turing patterns and traveling waves arises from a codimension-2 Turing-wave bifur

V. M. Eguiluz, M. Ospeck, Y. Choe, A. J. Hudspeth

Our hearing organ, the cochlea, evidently poises itself at a Hopf bifurcation to maximize tuning and amplification. We show that in this condition several effects are expected to be generic: compression of the dynamic range, infinitely shrap tuning at zero input, and generation of combination tones. These effects are "essentially" nonlinear in that t

M. Haskins, J. M. Speight

Qualitative information about breather initial profiles in the weak coupling limit of a chain of identical one-dimensional anharmonic oscillators is found by studying the linearized equations of motion at a one-site breather. In particular, information is found about how the breather initial profile depends on its period T. Numerical work shows two different

Erik M. Bollt, Theodore Stanford, Ying-Cheng Lai, Karol Zyczkowski

A practical and popular technique to extract the symbolic dynamics from experimentally measured chaotic time series is the threshold-crossing method, by which an arbitrary partition is utilized for determining the symbols. We address to what extent the symbolic dynamics so obtained can faithfully represent the phase-space dynamics. Our principal result is th

Jan Łopuszański

Suppose we have two nonequivalent but s-equivalent Lagrange functions, the question arises: are they both equally well fitted for the Feynman quantization procedure or do they lead to two different quantization schemes.

E. Esteves, Mathieu Gagne, S. Kleiman

We sharpen the two main tools used to treat the compactified Jacobian of a singular curve: Abel maps and presentation schemes. First we prove a smoothness theorem for bigraded Abel maps. Second we study the two complementary filtrations provided by the images of certain Abel maps and certain presentation schemes. Third we study a lifting of the Abel map of b

Vladimir Hinich, Arkady Vaintrob

We prove that the algebra $\cal{A}$ of chord diagrams, the dual to the associated graded algebra of Vassiliev knot invariants, is isomorphic to the universal enveloping algebra of a Casimir Lie algebra in a certain tensor category (the PROP for Casimir Lie algebras). This puts on a firm ground a known statement that the algebra $\cal{A}$ ``looks and behaves

Antonella Grassi, David R. Morrison

To every elliptic Calabi-Yau threefold with a section $X$ there can be associated a Lie group $G$ and a representation $ρ$ of that group. The group is determined from the Weierstrass model, which has singularities that are generically rational double points; these double points lead to local factors of $G$ which are either the corresponding A-D-E groups or s

C. A. Akemann, G. C. Shell, N. Weaver

There is a hierarchy of structure conditions for convex sets. In this paper we study a recently defined [3, 8, 9] condition called locally nonconical convexity (abbreviated LNC). Is is easy to show that every strictly convex set is LNC, as are half-spaces and finite intersections of sets of either of these types, but many more sets are LNC. For instance, eve

Hugh Nelson Howards

Given a properly embedded graph Gamma in a ball B and a punctured sphere Sigma properly embedded in B - Gamma, we examine the conditions on Gamma that are necessary to assure that Sigma is boundary parallel.

Metin Aktay

Goldbach`s Conjecture, "every even number greater than 2 can be expressed as the sum of two primes" is renamed Goldbach`s Rule for it can not be otherwise. The conjecture is proven by showing that the existence of prime pairs adding to any even number greater than 2 is a natural by-product of the existence of the prime sequence less than that even nu

Anton Deitmar

Generalizing the algebra of motion-invariant differential operators on a symmetric space we study invariant operators on equivariant vector bundles. We show that the eigenequation is equivalent to the corresponding eigenequation with respect to the larger algebra of all invariant operators. We compute the possible eigencharacters and show that for invariant

I. V. Bayak

It is shown that application of dynamic flows concept in 4-dimensional Euclidean space makes possible to form Minkowski space and to formulate the generalized variational problem of electrodynamics and gravi- dynamics. It is shown that 1-dimensional (cylindrical) factorization of 4-dimensional Euclidean space provides a quantization of ths model.

I. V. Bayak

It is investigated a possibility of physical interpretation of vector fields (dynamic flows) in Euclidean spaces of higher dimension. There are analyzed the methods of measurements of dynamic flows, the characteristics of dynamic flow and the connection between its differential and integral characteristics. It is obtained the criterion of local minimality of

Ron Donagi, Burt A. Ovrut, Tony Pantev, Daniel Waldram

We present a class of N=1 supersymmetric models of particle physics, derived directly from heterotic M-theory, that contain three families of chiral quarks and leptons coupled to the gauge group $SU(3)_C\times SU(2)_{L}\times U(1)_{Y}$. These models are a fundamental form of ``brane-world'' theories, with an observable and hidden sector each confined

Juan Maldacena, Hirosi Ooguri, John Son

We consider the one-loop partition function for Euclidean BTZ black hole backgrounds or equivalently thermal AdS_3 backgrounds which are quotients of H_3 (Euclidean AdS_3). The one-loop partition function is modular invariant and we can read off the spectrum which is consistent to that found in hep-th/0001053. We see long strings and discrete states in agree

Al. Zamolodchikov

Two implicit periodic structures in the solution of sinh-Gordon thermodynamic Bethe ansatz equation are considered. The analytic structure of the solution as a function of complex $θ$ is studied to some extent both analytically and numerically. The results make a hint how the CFT integrable structures can be relevant in the sinh-Gordon and staircase models.

Cumrun Vafa

We discuss unifying features of topological field theories in 2, 3 and 4 dimensions. This includes relations among enumerative geometry (2d topological field theory) link invariants (3d Chern-Simons theory) and Donaldson invariants (4d topological theory).

Robert Y. Levin, Victor Dannon

We propose that the principles of relativistic quantum mechanics are incomplete for simultaneous measurement of non-commuting operators. Consistent joint measurement of incompatible observables at a single point in space-time requires that the system be in an entangled state with vacuum meters. We suggest that entagled simultaneous mesurement for noncommutin

Koh-ichi Nittoh

We consider the quadratic divergence of the Yang-Mills theory when we use the hybrid regularization method consisting of the higher covariant derivative terms and the Pauli-Villars fields. By the explicit calculation of the diagrams, we show that the higher derivative terms for the ghost fields are necessary for the complete cancellation of the quadratic div

A. Konechny, A. Schwarz

A maximally supersymmetric configuration of super Yang-Mills living on a noncommutative torus corresponds to a constant curvature connection. On a noncommutative toroidal orbifold there is an additional constraint that the connection be equivariant. We study moduli spaces of (equivariant) constant curvature connections on noncommutative even-dimensional tori

Riccardo Barbieri, Alessandro Strumia

We assume that the scale of the soft supersymmetry breaking masses, m_SUSY, sliding at tree level, is fixed by the minimization of the potential, but without a significant contribution of the cosmological term. Under these assumptions the electroweak breaking scale gets related to m_SUSY by a loop factor. Applied to specific models of supersymmetry breaking,

B. Borasoy, G. Muller

The complete renormalization of the weak Lagrangian to chiral order q^2 in heavy baryon chiral perturbation theory is performed using heat kernel techniques. The results are compared with divergences appearing in the calculation of Feynman graphs for the nonleptonic hyperon decay Lambda -> p pi^- and an estimate for the size of the counterterm contributions

V. R. Zoller

Based on the color dipole representation, we investigate consequences for the $γ^{*}γ^{*},γ^{*}γ$ scattering of the finding by Fadin, Kuraev and Lipatov that incorporation of asymptotic freedom into the BFKL equation makes the QCD pomeron a series of isolated poles in the angular momentum plane. We present parameter-free predictions for the vacuum exchange c

Edmond L. Berger, Michael Klasen, Tim M. P. Tait

NLO SUSY-QCD contributions to associated production of gluinos and gauginos are shown to enhance the cross sections by about 10% at the Tevatron and by as much as a factor of two at the LHC. They shift the mass determinations or discovery limits, soften the $p_T$ spectra, and stabilize the predictions against variations of the renormalization and factorizati

G. S. Sharov

The dynamics of baryon string model Y (three-string) is considered with using the approach that implies defining a classical motion of the system on the base of given initial position and initial velocities of string points. The analysis resulted, in particular, in the necessity of regarding more wide (than it was supposed earlier) class of parametrizations

The WA102 Collaboration, D. Barberis

The reaction pp -> pf (omega omega) ps has been studied at 450 GeV/c and a spin analysis of the omega omega channel has been performed for the first time in central production. Evidence is found for the f2(1910) in the JPC = 2++ wave with spin projection JZ = 2. This is the only state observed in central production with spin projection JZ = 2. Its dPT and ph

F. Fucito

In this talk I review recent progresses in the detection of scalar gravitational waves. Furthermore, in the framework of the Jordan-Brans-Dicke theory, I compute the signal to noise ratio for a resonant mass detector of spherical shape and for binary sources and collapsing stars. Finally I compare these results with those obtained from laser interferometers

Juan A. Valiente-Kroon

The convergence of polyhomogeneous expansions of zero-rest-mass fields in asymptotically flat spacetimes is discussed. An existence proof for the asymptotic characteristic initial value problem for a zero-rest-mass field with polyhomogeneous initial data is given. It is shown how this non-regular problem can be properly recast as a set of regular initial val

Keith Anguige

We prove the existence of a class of perfect-fluid cosmologies with polarised Gowdy symmetry and a Kasner-like singularity. These solutions of the Einstein equations depend on four free functions of one space coordinate and are constructed by solving a system of Fuchsian equations.

Alessandro Lonardo, Emanuele Panizzi, Benedetto Proietti

The aim of this work is to define and implement an extended C++ language to support the SIMD programming paradigm. The C++ programming language has been extended to express all the potentiality of an abstract SIMD machine consisting of a central Control Processor and a N-dimensional toroidal array of Numeric Processors. Very few extensions have been added to

Massimo Conti, Baruch Meerson, Pavel V. Sasorov

We extend a previous analysis [PRL {\bf 80}, 4693 (1998)] of breakdown of dynamical scale invariance in the coarsening of two-dimensional DLAs (diffusion-limited aggregates) as described by the Cahn-Hilliard equation. Existence of a second dynamical length scale, predicted earlier, is established. Having measured the "solute mass" outside the cluster

W. Y. Tam, A. D. Rutenberg, B. P. Vollmayr-Lee, K. Y. Szeto

The persistent decay of bubble clusters in coarsening two-dimensional soap froths is measured experimentally as a function of cluster volume fraction. Dramatically stronger decay is observed in comparison to soap froth models and to measurements and calculations of persistence in other systems. The fraction of individual bubbles that contain any persistent a

G. M. Viswanathan, S. V. Buldyrev, E. K. Garger, V. A. Kashpur

We analyze nonstationary $^{137}$Cs atmospheric activity concentration fluctuations measured near Chernobyl after the 1986 disaster and find three new results: (i) the histogram of fluctuations is well described by a log-normal distribution, (ii) there is a pronounced spectral component with period T=1 y, and (iii) the fluctuations are long-range correlated.

David W. Snoke

The basic results of optical line broadening and four-wave mixing are deduced from first principles based on time-dependent many-body purturbation theory. The formalism allows us to write all the results in terms of nonequilibrium distribution functions without the need to assume a quasiequilibrium temperature. The connection of these results to the quantum

Misha Turlakov, Anthony J. Leggett

A theoretical model of c-axis transport properties in cuprates is proposed. Inter-plane and in-plane charge fluctuations make hopping between planes incoherent and diffusive (the in-plane momentum is not conserved after tunneling). The non-Drude optical conductivity $σ_c(ω)$ and the power-law temperature dependence of the {\it dc} conductivity are genericall

A. Campana, M. Corti, A. Rigamonti, R. Cantelli

Anelastic relaxation and $^{139}$La NQR relaxation measurements in La$_{2-x}$Sr$_x$CuO$_4$ for Sr content x around 2 and 3 percent, are presented and discussed in terms of spin and lattice excitations and ordering processes. It is discussed how the phase diagram of La$_{2-x}$Sr$_x$CuO$_4$ at the boundary between the antiferromagnetic (AF) and the spin-glass

V. Dananic, A. Bjelis, M. Latkovic

The basic Landau model for uniaxial systems of the II class is nonintegrable, and allows for various stable and metastable periodic configurations, beside that representing the uniform (or dimerized) ordering. In the present paper we complete the analysis of this model by performing the second order variational procedure, and formulating the combined Floquet

Vijay Shenoy, Ashutosh Sharma

We investigate the question of stability of a solid thin film which experiences external interactions such as van der Waals forces from a contacting surface or forces from an external electric field. Both perfectly elastic and viscoelastic material behaviours are considered in linear stability analysis performed here. These analyses indicate that for suffici

Erich J. Mueller, Gordon Baym

We study the mechanical stability of the weakly interacting Bose gas with attractive interactions, and construct a unified picture of the collapse valid from the low temperature condensed regime to the high temperature classical regime. As we show, the non-condensed particles play a crucial role in determining the region of stability, even providing a mechan

Christian Knetter, Alexander Buehler, Erwin Mueller-Hartmann, Goetz S. Uhrig

Bound states made from two triplet excitations on the Shastry-Sutherland (ShaSu) lattice are investigated. Based on the perturbative unitary transformation by flow equations quantitative properties like dispersions and qualitative properties like symmetries are determined. The high order results (up to (J_2/J_1)^{14}) permit to fix the parameters of SrCu_2(B

Nigel Clarke, Jose A Cuesta, Richard Sear, Peter Sollich

We study the phase behaviour of the Zwanzig model of suspensions of hard rods, allowing for polydispersity in the lengths of the rods. In spite of the simplified nature of the model (rods are restricted to lie along one of three orthogonal axes), the results agree qualitatively with experimental observations: the coexistence region broadens significantly as

Andrew Matacz

In this paper I develop a new computational method for pricing path dependent options. Using the path integral representation of the option price, I show that in general it is possible to perform analytically a partial averaging over the underlying risk-neutral diffusion process. This result greatly eases the computational burden placed on the subsequent num

Simon F. Norrelykke, Per Bak

A simple model economy with locally interacting producers and consumers is introduced. When driven by extremal dynamics, the model self-organizes {\em not} to an attractor state, but to an asymptote, on which the economy has a constant rate of deflation, is critical, and exhibits avalanches of activity with power-law distributed sizes. This example demonstra

S. Panyukov, Y. Rabin

We examine the effects of thermal fluctuations on thin elastic filaments with non-circular cross-section and arbitrary spontaneous curvature and torsion. Analytical expressions for orientational correlation functions and for the persistence length of helices are derived, and it is found that this length varies non-monotonically with the strength of thermal f

C. H. Booth, J. S. Gardner, G. H. Kwei, R. H. Heffner

The geometrically-frustrated spin glass Y2Mo2O7 has been considered widely to be crystallographically ordered with a unique nearest neighbor magnetic exchange interaction, J. To test this assertion, we present x-ray-absorption fine-structure results for the Mo and Y K edges as a function of temperature and compare them to results from a well-ordered pyrochlo

K. Xia, P. J. Kelly, G. E. W. Bauer, I. Turek

We study the effect of interface disorder on the spin-dependent interface resistances of Co/Cu, Fe/Cr and Au/Ag multilayers using a newly developed method for calculating transmission matrices from first-principles. The efficient implementation using tight-binding linear-muffin-tin orbitals allows us to model interface disorder using large lateral supercells

L. Vitos, H. L. Skriver, B. Johansson, J. Kollár

We present a self-consistent electronic structure calculation method based on the {\it Exact Muffin-Tin Orbitals} (EMTO) Theory developed by O. K. Andersen, O. Jepsen and G. Krier (in {\it Lectures on Methods of Electronic Structure Calculations}, Ed. by V. Kumar, O.K. Andersen, A. Mookerjee, Word Scientific, 1994 pp. 63-124) and O. K. Andersen, C. Arcangeli

P. Chaddah, S. B. Roy

The mixed state of type II superconductors has magnetic flux penetrating the sample in the form of vortices, with each vortex carrying an identical quantum of flux. These vortices generally form a triangular lattice under weak mutually repulsive forces; the lattice spacing can be easily varied over many orders of magnitude by varying the external magnetic fi

Xiao-Wen Zhang, Xi Liu, Zhi-Rong Liu, Bing-Lin Gu

Dielectric nonlinear response of (PbMg$_{1/3}$Nb$_{2/3}$O$_3$)$_{0.9}$(PbTiO$_3$)$_{0.1}$ (0.9PMN-0.1PT) relaxor ceramics was investigated under different ac drive voltages. It was observed that: (i) the dielectric permittivity is independent on ac field amplitude at high temperatures; (ii) with increasing ac drive, the permittivity maximum increases, and th

R. Moessner, S. L. Sondhi

We consider the problem of the doped Ising antiferromagnet on the frustrated triangular lattice in the limit where the hole kinetic energy is much smaller than the Ising exchange. For a {\it single} hole we prove a ``frustrated Nagaoka theorem'' showing that the ground state is magnetized and breaks translational symmetry, in contrast to the parent i

D. L. Khokhlov

It is considered the model of the homogeneous and isotropic universe. The scale of length is defined via the laboratory scale of time by the motion of photon. This leads to the appearance of the inertial forces. The properties of the space and time are defined both by these inertial forces and by the matter. Within the framework of classical physics, the sca

J. Carpenter, S. Desch, T. F. Lin, J. Poirier

The high energy gamma ray sources provided by experiment EGRET on the Compton Gamma Ray Observatory are examined, testing Project GRAND's ability to detect primary gamma rays by means of studying secondary muons. There is ~1.5% chance that a 100 GeV primary cosmic gamma ray will produce a muon at detection level (Fasso & Poirier, 1999), a probability whi

X. Fan, R. L. White, M. Davis, R. H. Becker

We present observations of SDSSp J104433.04--012502.2, a luminous quasar at z=5.80 discovered from Sloan Digital Sky Survey (SDSS) multicolor imaging data. This object was selected as an i'-band dropout object, with i*=21.8 +/- 0.2, z*=19.2 +/- 0.1. It has an absolute magnitude M1450 = -27.2 (H_0 =50 km/s/Mpc, q0 = 0.5). The spectrum shows a strong and b

Xavier Siemens, Xavier Martin, Ken D. Olum

We perform numerical simulations of cosmic necklaces (systems of monopoles connected to two strings each) and investigate the conditions under which monopoles annihilate. When the total monopole energy is large compared to the string energy, we find that the string motion is no longer periodic, and thus the strings will be chopped up by self intersection. Wh

William H. Kinney

With the release of the data from the Boomerang and MAXIMA-1 balloon flights, estimates of cosmological parameters based on the Cosmic Microwave Background (CMB) have reached unprecedented precision. In this paper I show that it is possible for these estimates to be substantially biased by features in the primordial density power spectrum. I construct primor

E. M. Murphy, K. R. Sembach, B. K. Gibson, J. M. Shull

We present Far Ultraviolet Spectroscopic Explorer (FUSE) observations of the sightline toward the Seyfert 1 galaxy Markarian 876, which passes through high velocity cloud (HVC) complex C. This sight line demonstrates the ability of FUSE to measure ionic absorption lines in Galactic HVCs. High velocity absorption is clearly seen in both members of the O VI do

J. S. Lazendic, J. R. Dickel, R. F. Haynes, P. A. Jones

A new investigation of the supernova remnant (SNR) N157B was carried out with the Australia Telescope Compact Array. Radio continuum images of the entire 30 Doradus region have been made at 3.5 and 6 cm wavelength with a resolution of 2". These data allow a high resolution study of the spectral index distribution and polarization properties of both N157B

N. W. Evans, S. A. Tabachnik

This paper presents synthetic observations of long-lived, coorbiting asteroids of Mercury, Venus, the Earth and Mars. Our sample is constructed by taking the limiting semimajor axes, differential longitudes and inclinations for long-lived stability provided by simulations. The intervals are randomly populated with values to create initial conditions. These o

Patrik Thoren

An apparent Ca underabundance for cool metal rich disk dwarfs was derived by Feltzing & Gustafsson (1998, A&AS, 129, 237). This was suggested to be a NLTE effect, following the prediction by Drake (1991, MNRAS, 251, 369). New NLTE calculations with MARCS atmospheres and opacities (Thorén, P., 2000, A&A, in preparation) show that deviations from LTE are very

J. D. Offenberg, R. J. Hanisch, D. J. Fixsen, H. S. Stockman

We present a data simulation package designed to create a series of simulated data samples for a detector with non-destructive sampling capability. The original intent of this software was to provide a method for generating simulated images for the Next Generation Space Telescope, but it is general enough to apply to almost any non-destructive detector or in

S. B. Popov, M. E. Prokhorov

The influence of exponential magnetic field decay (MFD) on the spin evolution of isolated neutron stars is studied. The ROSAT observations of several X-ray sources, which can be accreting old isolated neutron stars, are used to constrain the exponential and power-law decay parameters. We show that for the exponential decay the ranges of minimum value of magn

W. Wild, A. Eckart

The interstellar medium of Centaurus A (NGC 5128) has been studied extensively in recent years, using mostly molecular lines tracing low to medium density gas (500 to several $10^3$ cm$^{-3}$). The amount and distribution of the dense molecular gas was largely unknown. Here we present new millimeter data of the HCN(1-0), CS(2-1), and CS(3-2) rotational trans

S. A. Tabachnik, N. W. Evans

Ensembles of in-plane and inclined orbits in the vicinity of the Lagrange points of the terrestrial planets are integrated for up to 100 million years. The integrations incorporate the gravitational effects of Sun and the eight planets (Pluto is neglected). Mercury is the least likely planet, as it is unable to retain tadpole orbits over 100 million year tim

John P. Hughes, Patrick O. Slane, Paul P. Plucinsky

G328.4+0.2 is a moderately small (5 arcmin x 5arcmin) Galactic radio supernova remnant (SNR) at a distance of at least 17 kpc that has been long suggested to be Crab-like. Here we report on the detection with ASCA of the X-ray emission from the SNR. The X-ray source is faint with an observed flux of (6.0 +/- 0.8)E-13 erg/s/cm^2 over the 2-10 keV band. The em

T. Di Salvo, R. Iaria, L. Burderi, N. R. Robba

We report on the results of a broad band (0.1-100 keV) spectral analysis of the bursting atoll source MXB 1728-34 observed by the BeppoSAX satellite. Three bursts were present during this observation. The spectrum during the bursts can be fitted by a blackbody with a temperature of 2 keV. From the bursts we also estimate a distance to the source of 5.1 kpc.

V. N. Lukash, E. V. Mikheeva, V. Muller, A. M. Malinovsky

We propose a Lambda-inflation model which explains a significant part of the COBE signal by primordial cosmic gravitational waves. The primordial density perturbations fulfill both the constraints of large-scale microwave background and galaxy cluster normalization. The model is tested against the galaxy cluster power spectrum and the high-multipole angular

K. Hirotani, S. Iguchi, M. Kimura, K. Wajima

We investigate whether a pc-scale jet of 3C345 is dominated by a normal plasma or an electron-positron plasma. We present a general condition that a jet component becomes optically thick for synchrotron self-absorption, by extending the method originally developed by Reynolds et al. The general condition gives a lower limit of the electron number density, wi

C. H. Ishwara-Chandra, D. J. Saikia

We present the results of multi-wavelength observations of cores and hotspots at L, C, X and U bands with the Very Large Array, of a matched sample of radio galaxies and quasars selected from the Molonglo Reference Catalogue. We use these observations to determine the spectra of cores and hotspots, and test the unified scheme for radio galaxies and quasars.

Nicolas Grosso, Thierry Montmerle, Sylvain Bontemps, Philippe Andre

We have obtained two deep exposures of the rho Oph cloud core region with the ROSAT HRI. The improved position accuracy (1"-6") with respect to previous recent X-ray observations (ROSAT PSPC, and ASCA) allows us to remove positional ambiguities for the detected sources. We also cross-correlate the X-ray positions with IR sources found in the ISO-ISOC

Naoki Itoh, Youhei Kawana, Satoshi Nozawa, Yasuharu Kohyama

We extend the formalism for the calculation of the relativistic corrections to the Sunyaev-Zel'dovich effect for clusters of galaxies and include the multiple scattering effects. We present a systematic method for the inclusion of the multiple scattering effects. The multiple scattering contribution is found to be very small compared with the single scat

M. D. Ding, C. Fang

We explore the possibility that the continuum emission in stellar flares is powered by nonthermal electrons accelerated during the flares. We compute the continuum spectra from an atmospheric model for a dMe star, AD Leo, at its quiescent state, when considering the nonthermal excitation and ionisation effects by precipitating electron beams. The results sho

Rosalba Perna, John Raymond, Ramesh Narayan

We compute X-ray emission lines from thermal plasma in hot accretion flows. We show that line profiles are strong probes of the gas dynamics, and we present line-ratio diagnostics which are sensitive to the distribution of mass with temperature in the flow. We show how these can be used to constrain the run of density with radius, and the size of the hot reg

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

The improvement of resummation algorithms for divergent perturbative expansions in quantum field theory by asymptotic information about perturbative coefficients is investigated. Various asymptotically optimized resummation prescriptions are considered. The improvement of perturbative predictions beyond the reexpansion of rational approximants is discussed.

A. M. Polyakov, V. S. Rychkov

We consider the strong coupling limit of conformal gauge theories in 4 dimensions. The action of the loop operator on the minimal area in the AdS space is analyzed, and the Schwinger-Dyson equations of gauge theory are checked. The general approach to the loop dynamics developed here goes beyond the special case of conformal theories.

Vesselin Petkov

In general relativity the gravitational field is a manifestation of spacetime curvature and unlike the electromagnetic field is not a force field. A particle falling in a gravitational field is represented by a geodesic worldline which means that no force is acting on it. If the particle is at rest in a gravitational field, however, its worldline is no longe

H. C. G. Caldas, A. L. Mota, M. C. Nemes

We study the chiral fermion meson model which is the well known linear sigma model of Gell-Mann-and-Levy at finite temperature.A modified self-consistent resummation (MSCR) which resums higher order terms in the perturbative expansion is proposed. It is shown that with the MSCR the problem of tachyonic masses is solved, the renormalization of the gap equatio

Abhay Ashtekar, Stephen Fairhurst, Badri Krishnan

A framework was recently introduced to generalize black hole mechanics by replacing stationary event horizons with isolated horizons. That framework is significantly extended. The extension is non-trivial in that not only do the boundary conditions now allow the horizon to be distorted and rotating, but also the subsequent analysis is based on several new in

P. Hoxha, R. R. Martinez-Acosta, C. N. Pope

We make a detailed investigation of all spaces Q_{n_1... n_N}^{q_1... q_N} of the form of U(1) bundles over arbitrary products \prod_i CP^{n_i} of complex projective spaces, with arbitrary winding numbers q_i over each factor in the base. Special cases, including Q_{11}^{11} (sometimes known as T^{11}), Q_{111}^{111} and Q_{21}^{32}, are relevant for compact

V. A. De Lorenci, R. D. M. De Paola, N. F. Svaiter

In this work we compare the quantization of a massless scalar field in an inertial frame with the quantization in a rotating frame. We used the Trocheries-Takeno mapping to relate measurements in the inertial and the rotating frames. An exact solution of the Klein-Gordon equation in the rotating coordinate system is found and the Bogolubov transformation bet

Denes Molnar, Miklos Gyulassy

New solutions of 3+1D covariant kinetic theory are presented for nuclear collisions in the energy domain Ecm ~ 200 AGeV. They are obtained using MPC, a new Monte-Carlo parton transport technique that employs very high parton subdivision that is necessary to preserve covariance. The transport results are compared with ideal hydrodynamics solutions. We show th

T. T. Nguyen, B. I. Shklovskii

The complexation of a polyelectrolyte with an oppositely charged spherical macroion is studied for both salt free and salty solutions. When a polyelectrolyte winds around the macroion, its turns repel each other and form an almost equidistant coil. It is shown that this repulsive correlations of turns lead to the charge inversion: more polyelectrolyte winds

J. E. Simsarian, J. Denschlag, Mark Edwards, Charles W. Clark

We demonstrate a spatially resolved autocorrelation measurement with a Bose-Einstein condensate (BEC) and measure the evolution of the spatial profile of its quantum mechanical phase. Upon release of the BEC from the magnetic trap, its phase develops a form that we measure to be quadratic in the spatial coordinate. Our experiments also reveal the effects of

Wolfgang A. Rolke, Angel M. Lopez

We discuss a new method for setting limits on small signals in the presence of background noise. The method is based on a combination of a two dimensional confidence region and the large sample approximation to the likelihood ratio test statistic. It automatically quotes upper limits for small signals and two-sided confidence intervals for larger samples. We

A. Taramopoulos, H. Payne, F. H. Briggs

NGC 2146 is a peculiar spiral galaxy which is currently undergoing a major burst of star formation and is immersed in a extended HI structure that has morphological and kinematical resemblence to a strong tidal interaction. This paper reports aperture synthesis observations carried out in the 21cm line with the Very Large Array (VLA - The National Radio Astr

B. C. Allanach, J. P. J. Hetherington, M. A. Parker, B. R. Webber

We re-analyse the prospects of discovering supersymmetry at the LHC, in order to re-express coverage in terms of a fine-tuning parameter and to extend the analysis to scalar masses (m_0) above 2 TeV. We use minimal supergravity (mSUGRA) unification assumptions for the SUSY breaking parameters. The discovery reach at high m_0 is of renewed interest because th

Andrzej Krasinski

The program Ortocartan for algebraic calculations in relativity has just been implemented in the Codemist Standard Lisp and can now be used under the Windows 98 and Linux operating systems. The paper describes the new facilities and subprograms that have been implemented since the previous release in 1992. These are: the possibility to write the output as La

D. I. Kazakov, V. N. Velizhanin

It is shown that, due to soft supersymmetry breaking in gauge theories within the superfield formalism, there appears the mass for auxiliary gauge fields. It enters into the RG equations for soft masses of physical scalar particles and can be eliminated by solving its own RG equation. Explicit solutions up to the three-loop order in the general case and in t

K. Hashimoto, T. Ikegami

A replicator equation with mutation processes is numerically studied. Without any mutations, two characteristics of the replicator dynamics are known: an exponential divergence of the dominance period, and hierarchical orderings of the attractors. A mutation introduces some new aspects: the emergence of structurally stable attractors, and chaotic itinerant b

Tapobrata Sarkar

We discuss examples of D-branes probing toric singularities, and the computation of their world-volume gauge theories from the geometric data of the singularities. We consider several such examples of D-branes on partial resolutions of the orbifolds ${\bf C^3/Z_2\times Z_2}$,${\bf C^3/Z_2\times Z_3}$ and ${\bf C^4/Z_2\times Z_2 \times Z_2}$.

Andrzej J. Buras, Mikolaj Misiak, Joerg Urban

We calculate the two-loop QCD anomalous dimension matrix (ADM) gamma^(1)_NDR in the NDR-MSbar scheme for all the flavour-changing four-quark dimension-six operators that are relevant in both the Standard Model and its extensions. Both current-current and penguin diagrams are included. Some of our NDR-MSbar results for Delta F=1 operators overlap with the pre

L. Vitos, B. Johansson, J. Kollár, H. L. Skriver

The Airy gas model of the edge electron gas is used to construct an exchange-energy functional which is an alternative to those obtained in the local density and generalized gradient approximations. Test calculations for rare gas atoms, molecules, solids and surfaces show that the Airy gas functional performs better than the local density approximation in al

D. K. Park, S. N. Tamaryan, H. J. W. Müller-Kirsten, Jian-zu Zhang

Standard methods of nonlinear dynamics are used to investigate the stability of particles, branes and D-branes of abelian Born-Infeld theory. In particular the equation of small fluctuations about the D-brane is derived and converted into a modified Mathieu equation and - complementing earlier low-energy investigations in the case of the dilaton-axion system