November 1998 arXiv papers — page 12

A. Kadigrobov, L. Y. Gorelik, R. I. Shekhter, M. Jonson

We use a semiclassical approach for analysing the tunneling transport through a normal conductor in contact with superconducting mirrors. Our analysis of the electron-hole propagation along semiclassical trajectories shows that resonant transmission through Andreev levels is possible resulting in an excess, low-energy quasiparticle contribution to the conduc

Yupeng Wang

%auto-ignore Paper has been withdrawn by the author.

Ch. Renner, B. Reisner, St. Lück, J. Peinke

We present a method how to estimate from experimental data of a turbulent velocity field the drift and the diffusion coefficient of a Fokker-Planck equation. It is shown that solutions of this Fokker-Planck equation reproduce with high accuracy the statistics of velocity increments in the inertial range. Using solutions with different initial conditions at l

Fabrizio Brighenti, William G. Mathews

Hot, X-ray emitting gaseous halos around massive elliptical galaxies are a result of both stellar mass loss and inflow toward the overdensity from which giant ellipticals and their associated galaxy groups formed. The metal abundance in this gas contains important information about early star formation and past supernova activity. We find that Type II supern

Philip D. Mannheim

We show that a cosmological negative spatial curvature can account for both a recently identified phenomenological imprint of the global Hubble flow on galactic rotation curves and for the recently detected cosmic repulsion and cosmic acceleration. Even though such a negative curvature (a curvature which a galactic rest frame observer recognizes as a univers

B. P. Wakker, J. C. Howk, B. D. Savage, S. L. Tufte

We present observations of the (field of the) Seyfert galaxy Mark290, which probes the high-velocity cloud (HVC) complex C, one of the largest HVCs. We find that this object has a metallicity of 0.094pm0.020(+0.022-0.019) times solar. We determine a lower limit to its distance of 5 kpc (z>3.5 kpc). If the gas is in thermal equilibrium with a hot halo, then i

L. M. Chechin, T. B. Omarov

For the case of tension tensor containing nonlinear terms in $l^α$, we give generalization of Vilenkin metrics and equations of motion of cosmic string. Dynamics of nonlinear string in (1+1)-dimensional universe is discussed.

B. P. Wakker, B. D. Savage, T. A. Oosterloo, M. E. Putman

We present an analysis of high-resolution HI data of one of the cores of HVC187 Wakker & van Woerden 1991), HVC287+22+240. Structure is present down to the lowest-measurable scale (~1 arcmin) and several concentrations appear to be unresolved. Most of the cores seen at low resolution break up into smaller subcores at higher resolution. The typical volume den

L. F. Rodriguez, I. Felix Mirabel

We have carried out radio studies of the surroundings of the superluminal microquasar GRS~1915+105. Our main goal was to understand the possible relation of GRS~1915+105 with two infrared/radio sources that appear symmetrically located with respect to GRS~1915+105 and aligned with the position angle of the relativistic ejecta. We have also studied a nearby s

Ciska Kemper, Marco Spaans, David J. Jansen, Michiel R. Hogerheijde

ISO [C II] 158 micron, [O I] 63 micron, and H_2 9 and 17 micron observations are presented of the reflection nebula Ced 201, which is a photon-dominated region illuminated by a B9.5 star with a color temperature of 10,000 K (a cool PDR). In combination with ground based [C I] 609 micron, CO, 13CO, CS and HCO+ data, the carbon budget and physical structure of

Renyue Cen, Jeremiah P. Ostriker

We perform a variety of tests to determine the numerical resolution of the cosmological TVD eulerian code developed by Ryu et al (1993). Tests include 512^3 and 256^3 simulations of a Pk=k^{-1} spectrum to check for self-similarity and comparison of results with those from higher resolution SPH and grid-based calculations (Frenk et al 1998). We conclude that

M. Guainazzi, G. Matt, S. Molendi, A. Orr

We report the first simultaneous measure of the X-ray broadband (0.1--200 keV) continuum and of the iron K-alpha fluorescent line profile in the Seyfert 1 galaxy MCG-6-30-15. Our data confirms the ASCA detection of a skewed and redshifted line profile (Tanaka et al. 1995). The most straightforward explanation is that the line photons are emitted in the inner

Renato Falomo, Laura Maraschi, Elena Pian, Aldo Treves

The contribution of an astrophysics group based in Milan to the science with the IUE satellite during its almost 20 years lifetime has focussed on high energy sources, of both galactic (LMXRB, HMXRB, and black hole candidates) and extragalactic (AGN) nature. The results of this long term research and in particular of the latest multiwavelength campaigns cond

A. Treves, Y. H. Zhang, A. Celotti, F. Tavecchio

PKS 2155-304 is one of the prototypes of BL Lac objects. Its spectral energy distribution is known from the radio to the TeV band and has two peaks, one in the soft X-rays and the other in the TeV region. These may be interpreted within the synchrotron self-Compton model, which attributes the first peak to synchrotron radiation of electrons, which also produ

Tanusri Ghosh, Somenath Chakrabarty

The chemical evolution of nascent quark matter core in a newborn compact neutron star is studied in presence of a strong magnetic field. The effective rate of strange quark production in degenerate quark matter core in presence of strong magnetic fields is obtained. The investigations show that in presence of strong magnetic fields a quark matter core become

Joshua E. Barnes

Theoretical considerations and observational data support the idea that mergers were more frequent in the past. At redshifts z = 2 to 5, violent interactions and mergers may be implicated by observations of Lyman-break galaxies, sub-mm starbursts, and active galactic nuclei. Most stars in cluster ellipticals probably formed at such redshifts, as did most of

Gary Wegner, Matthew Colless, R. P. Saglia, Robert K. McMahan

We present the spectroscopic data for the galaxies studied in the EFAR project, which is designed to measure the properties and peculiar motions of early-type galaxies in two distant regions. We have obtained 1319 spectra of 714 early-type galaxies over 33 observing runs on 10 different telescopes. We describe the observations and data reductions used to mea

C. Alcock, R. A. Allsman, D. R. Alves, T. S. Axelrod

We present an analysis of the period distribution of $\sim 1800$ Cepheids in the Large Magellanic Cloud, based on data obtained by the MACHO microlensing experiment and on a previous catalogue by Payne-Gaposchkin. Using stellar evolution and pulsation models, we construct theoretical period-frequency distributions that are compared to the observations. These

Z. S. Bassi, A. LeClair

We introduce two massive versions of the anisotropic spin 1/2 Kondo model and discuss their integrability. The two models have the same bulk sine-Gordon interactions, but differ in their boundary interactions. At the Toulouse free fermion point each of the models can be understood as two decoupled Ising models in boundary magnetic fields. Reflection S-matric

Eugene A. Mirabelli, Maxim Perelstein, Michael E. Peskin

Recently, Arkani-Hamed, Dimopoulos, and Dvali have proposed that there are extra compact dimensions of space, accessible to gravity but not to ordinary matter, which could be macroscopically large. In this letter, we argue that high-energy collider processes in which gravitons are radiated into these new dimensions place significant, model-independent constr

Marco Frasca

The dual Dyson series [M.Frasca, Phys. Rev. A {\bf 58}, 3439 (1998)], is used to develop a general perturbative method for the study of atom-field interaction in quantum optics. In fact, both Dyson series and its dual, through renormalization group methods to remove secular terms from the perturbation series, give the opportunity of a full study of the solut

S. I. Bityukov, N. V. Krasnikov

We propose a method to estimate the probability of new physics discovery in future high energy physics experiments. Physics simulation gives both the average numbers <Nb> of background and <Ns> of signal events. We find that the proper definition of the significance for <Nb>, <Ns> >> 1 is S_{12} = sqrt(<Ns>+<Nb>) - sqrt(<Nb>) in comparison with often used si

Michael Gronau, Dan Pirjol

An improved flavor SU(3) method is presented for determining the weak angle $γ$ of the unitarity triangle using decay rates for $B^+\to Kπ, B^+\to K^+\bar K^0$ and $B^+\to π^+η$ (or $B^0\to Kπ$ and $B_s\to K π$), their CP-conjugate modes and the CP-averaged rate for $B^\pm\toπ^\pmπ^{0}$. Rescattering (color-suppressed) contribution in $B^+(B^0)\to Kπ$, for w

J. Ravi Prakash

The development of a coherent conceptual basis for the treatment of non-linear microscopic phenomena, such as, hydrodynamic interaction, finite extensibility, excluded volume and internal viscosity, in molecular theories of dilute polymer solutions, is discussed. In particular, recent advances in the treatment of hydrodynamic interaction are reviewed, and th

M. M. Sharma, S. Mythili, A. R. Farhan

We have investigated the ground-state properties of carbon isotopes in the framework of the relativistic mean-field (RMF) theory. RMF calculations have been performed with the non-linear scalar self-coupling of the $σ$ meson using an axially symmetric deformed configuration. We have also introduced the vector self-coupling of the $ω$ meson for the deformed m

Z. Bern, L. Dixon, M. Perelstein, J. S. Rozowsky

By exploiting relations between gravity and gauge theories, we present two infinite sequences of one-loop n-graviton scattering amplitudes: the `maximally helicity-violating&#39; amplitudes in N=8 supergravity, and the `all-plus&#39; helicity amplitudes in gravity with any minimally coupled massless matter content. The all-plus amplitudes correspond to self-

Ming-Hsien Tu

We study the additional symmetries associated with the $q$-deformed Kadomtsev-Petviashvili ($q$-KP) hierarchy. After identifying the resolvent operator as the generator of the additional symmetries, the $q$-KP hierarchy can be consistently reduced to the so-called $q$-deformed constrained KP ($q$-cKP) hierarchy. We then show that the additional symmetries ac

Daniel R. Terno

Quantum information theory is used to analize various non-linear operations on quantum states. The universal disentanglement machine is shown to be impossible, and partial (negative) results are obtained in the state-dependent case. The efficiency of the transformation of non-orthogonal states into orthogonal ones is discussed.

Ashwin Nayak, Felix Wu

Let X = (x_0,...,x_{n-1})$ be a sequence of n numbers. For ε> 0, we say that x_i is an ε-approximate median if the number of elements strictly less than x_i, and the number of elements strictly greater than x_i are each less than (1+ε)n/2. We consider the quantum query complexity of computing an ε-approximate median, given the sequence X as an oracle. We pro

K. A. Bugaev, U. Oelfke, P. U. Sauer

Photo disintegration of the deuteron and photo pionproduction on the deuteron are described in the region of the $Δ$-resonance. The two reactions are unitarily coupled. A novel definition of electromagnetic exchange currents in the presence of pionproduction is given. Numerical predictions are done for spin-independent and spin-dependent observables of both

J. Brian Conrey, David W. Farmer, Peter Jake Wallace

Let T^{N,chi}_{p,k}(x) be the characteristic polynomial of the Hecke operator T_p acting on the space of cusp forms S_k(N,chi). We describe the factorization of T^{N,chi}_{p,k}(x) mod l as k varies, and we explicitly calculate those factorizations for N=1 and small l. These factorizations are used to deduce the irreducibility of certain T^{1,1}_{q,k}(x) from

Saharon Shelah

We prove that for every (infinite cardinal) lambda there is a T_3-space X with clopen basis, 2^mu points where mu = 2^lambda, such that every closed subspace of cardinality <|X| has cardinality < lambda .

Tadahiko Kimura, Ichiro Oda

We show that supersymmetric and $κ$-symmetric Dp-brane actions in type II supergravity background have the same duality transformation properties as those in a flat Minkowskian background. Specially, it is shown that the super D-string transforms in a covariant way while the super D3-brane is self-dual under the $SL(2,Z)$ duality. Also, the D2-brane and the

Veronique Bernard, Thomas R. Hemmert, Ulf-G. Meissner

We summarize recent work on muon capture and the pseudoscalar form factor of the nucleon.

G. Bélanger, F. Boudjema, T. Kon, V. Lafage

We calculate stop stop Higgs production at the linear collider. Combining the measurements from the pair production of the lightest stop and that of the mass of the Higgs we show how, in a scenario where only the lightest stop and the lightest Higgs were accessible, one could extract the mass of the heavier stop and infer some useful information on the SUSY

R. Bilger, K. Foehl, H. Clement, M. Croeni

Recently, it has been proposed that the observed anomaly in the time distribution of neutrino induced reactions, reported by the KARMEN collaboration, can be interpreted as a signal from an exotic muon decay branch mu+ to e+ X. It has been shown that this hypothesis gives an acceptable fit to the KARMEN data if the boson X has a mass of m_X=103.9MeV/c^2, clo

Eli Cohen, L. P. Horwitz

We review the application of the Wigner-Weisskopf model to the two-channel decay problem for the neutral $K$ meson system in the resolvent formalism. The residues in the pole approximation are not orthogonal, leading to additional interference terms in the $K_S-K_L 2π$ channel. We show that these terms lead to non-trivial changes in the exit beam in comparis

Yong Liu

By using the relation between CP-violation phase and the mixing angles in Cabibbo-Kobayashi-Maskawa matrix postulated by us before, the rephasing invariant is recalculated. Furthermore, the problem about maximal CP violation is discussed. We find that the maximal value of Jarlskog&#39;s invariant is about 0.038. And it presents at alpha=1.239, beta=1.574 and

E. -M. Ilgenfritz, S. V. Molodtsov, M. Müller-Preussker, A. I. Veselov

Finite temperature SU(2) lattice gauge theory is investigated in a 3D cubic box with fixed boundary conditions (b.c.) provided by a discretized, static BPS monopole solution with varying core scale $μ$. For discrete $μ$-values we find stable classical solutions either of electro-magnetic (&#39;dyon&#39;) or of purely magnetic type inside the box. Near the de

Zoltan Csahok, Chaouqi Misbah, Alexandre Valance

From geometry and conservation we derive two nonlinear evolution equations for sand ripples. In the case of a strong wind leading to a net erosion of the sand bed, ripples obey the Benney equation. This leads either to order or disorder depending on whether dispersion is strong or weak. In the most frequent case where erosion is counterbalanced by deposition

R. B. Stinchcombe, J. E. Santos, M. D. Grynberg

Non-universal dynamics is shown to occur in a one-dimensional non-equilibrium system of hard-core particles. The stochastic processes included are pair creation and annihilation (with rates e and e&#39;) and symmetric hopping rates which alternate from one bond to the next (Pa, Pb). A dynamical scaling relation between the relaxation time and the correlation

Ido Golding, Inon Cohen, Eshel Ben-Jacob

Segregation of populations is a key question in evolution theory. One important aspect is the relation between spatial organization and the population&#39;s composition. Here we study a specific example -- sectors in expanding bacterial colonies. Such sectors are spatially segregated sub-populations of mutants. The sectors can be seen both in disk-shaped col

Beverly J. Smith, Curtis Struck, Jeffrey D. P. Kenney, Shardha Jogee

We present the first detection of a large quantity of molecular gas in the extended tail of an interacting galaxy. Using the NRAO 12m telescope, we have detected CO (1 - 0) at five locations in the eastern tail of the peculiar starburst galaxy NGC 2782. The CO velocities and narrow (FWHM = 50 km/s) line widths in these positions agree with those seen in HI,

Magdalen Normandeau, Shantanu Basu

Galaxies are surrounded by large halos of hot gas which must be replenished as the gas cools. This led Norman & Ikeuchi (1989) to propose the chimney model of the interstellar medium, which predicts that there should be on the order of a thousand such conduits connecting the disk and the halo of a galaxy. Where then are these structures and other possible di

R. Maiolino, G. Risaliti, M. Salvati

We present evidence for a strong correlation between the gaseous absorbing column density towards type 2 Seyfert nuclei and the presence of a stellar bar in their host galaxies. Strongly barred Seyfert 2 galaxies have an average Nh that is two orders of magnitude higher than non-barred Sy2s. More than 80% of Compton thick (Nh>10^24 cm^-2) Seyfert 2s are barr

D. Barret, L. Boirin, J. F. Olive, J. E. Grindlay

The type I X-ray burster and dipper 4U1915-05 (also known as XB1916-053) was monitored by the Rossi X-ray Timing Explorer between February and October, 1996. The source was observed in various spectral states; the highest luminosity state (LX ~ 1.5 10^37 ergs/s, 10 kpc, 1-20 keV) is associated with a soft spectrum, whereas for the lower luminosity state (dow

J. C. Vega Beltran, E. Pignatelli, W. W. Zeilinger, A. Pizzella

We present a comparison between ionized gas and stellar kinematics for a sample of 5 early-to-intermediate disk galaxies. We measured the major axis V and velocity dispersion radial profiles for both gas and stars, and the h_3 and h_4 radial profiles of the stars. We also derived from the R-band surface photometry of each galaxy the light contribution of the

Keshav Dasgupta, Sunil Mukhi

We show that a set of parallel 3-brane probes near a conifold singularity can be mapped onto a configuration of intersecting branes in type IIA string theory. The field theory on the probes can be explicitly derived from this formulation. The intersecting-brane metric for our model is obtained using various dualities and related directly to the conifold metr

Valery P. Gusynin, Vadim M. Loktev, Sergei G. Sharapov

The effect of static fluctuations in the phase of the order parameter on the normal and superconducting properties of a 2D system with attractive four-fermion interaction is studied. Analytic expressions for the fermion Green&#39;s function, its spectral density, and the density of states are derived in the approximation where the coupling between the spin a

R. Prozorov, Y. Yeshurun, T. Prozorov, A. Gedanken

Measurements of the magnetic irreversibility line and time-logarithmic decay of the magnetization are described for three $Fe_{2}O_{3}$ samples composed of regular amorphous, acicular amorphous and crystalline nanoparticles. The relaxation rate is the largest and the irreversibility temperature is the lowest for the regular amorphous nanoparticles. The cryst

Constantia Alexandrou, Iacovos Kyprianou

We study a model inspired by the pinball machine involving chaotic scattering of particles on hard disks with inelasticity. This system exhibits sensitivity not only on the initial conditions of the scattering point particle but also on the external force produced by the pinballs. The deflection function shows fractal structure with regions of wild oscillati

G. A. Miller, R. Machleidt

A relativistic light front formulation of nuclear dynamics is applied to infinite nuclear matter. A hadronic meson-baryon Lagrangian, consistent with chiral symmetry, leads to a nuclear eigenvalue problem which is solved, including nucleon-nucleon (NN) correlations, in the one-boson-exchange approximation for the NN potential. The nuclear matter saturation p

David I. Santiago Alexander S. Silbergleit

We give a complete description of the asymptotic behavior of a Friedmann-Robertson-Walker Universe with ``normal&#39;&#39; matter and a minimally coupled scalar field. We classify the conditions under which the Universe is or is not accelerating. In particular, we show that only two types of large time behavior exist: an exponential regime, and a subexponent

John Ellis, Zygmunt Lalak, Witold Pokorski

We extend the formulation of gauged supergravity in five dimensions, as obtained by compactification of $M$~theory on a deformed Calabi-Yau manifold, to include non-universal matter hypermultiplets. Even in the presence of this gauging, only the graviton supermultiplets and matter hypermultiplets can couple to supersymmetry breaking sources on the walls, tho

R. L. Jaffe

A transcription with minor alterations of the talk presented to honor Sid Drell on the occasion of his retirement.

G. J. Yang, O. Zobay, P. Meystre

The center-of-mass motion of two two-level atoms coupled to a single damped mode of an electromagnetic resonator is investigated. For the case of one atom being initially excited and the cavity mode in the vacuum state it is shown that the atomic time evolution is dominated by the appearance of dark states. These states, in which the initial excitation is st

H. Mitter, D. Robaschik

We study the Casimir effect with different temperatures between the plates ($T$) resp. outside of them ($T&#39;$). If we consider the inner system as the black body radiation for a special geometry, then contrary to common belief the temperature approaches a constant value for vanishing volume during isentropic processes. This means: the reduction of the deg

Luis Santos, Luis Roso

We show that under certain circumstances an atom can follow an oscillatory motion in a periodic laser profile with a Gaussian envelope. These oscillations can be well explained by using a model of energetically forbidden spatial regions. The similarities and differences with Bloch oscillations are discussed. We demonstrate that the effect exists not only for

B. G. Sidharth

It is shown, in the context of a recent formulation of elementary particles in terms of, what may be called, a Quantum Mechanical Kerr-Newman metric, that spin is a consequence of a space-time cut off at the Compton wavelength and Compton time scale. On this basis, we deduce the Dirac equation from a simple coordinate transformation.

K. Kaki, S. Hirenzaki

We study theoretically how we can determine the neutron density distributions of unstable nuclei from proton elastic scattering. We apply the relativistic impulse model to study the sensitivities of the observables to the density distributionswhich are expressed in Woods-Saxon form. We find that the both radius and diffuseness of densities can be determined

Yu. P. Gouz, S. R. Slabospitsky

We calculate the contribution of anomalous top-quark interaction with a gluon, photon, and $Z$-boson (FCNC) to $t \bar t$ pair production in hadronic collisions. Using the current data from Run~1 of the Tevatron we evaluate the upper limit on the the anomalous coupling of $t$-quark with gluon, $|κ_g/Λ| \le 0.52$ TeV$^{-1}$. We examine the production of doubl

T. Morii

Requiring the positivity and counting rule, we propose a new parametrization of the polarized parton distribution which reproduce the data well. We found that the NLO analysis is absolutely necessary to extract the correct information on the polarized gluon distributions. The calculated results of $xΔd_v(x)$ and $Δd_v(x)/d_v(x)$ seem to be consistent with th

A. A. Babich, A. A. Pankov, N. Paver

We study the sensitivity to the Z&#39; couplings of the processes $e^+e^-\to l^+l^-,\bar{b}b$ and $\bar{c}c$ at the linear collider with $\sqrt{s}=500 GeV$ with initial beam polarization, for typical extended model examples. To this aim, we use suitable integrated, polarized, observables directly related to the helicity cross sections that carry information

S. T. Petcov

The characteristic features of the neutrino oscillation length resonance, taking place in the $ν_2 \to ν_{e}$ and $ν_μ \to ν_{e}$ ($ν_e \to ν_{μ(τ)}$) transitions in the Earth of the solar and atmospheric neutrinos crossing the Earth core, are reviewed. The resonance enhances dramatically these transitions at small mixing angles but differs from the MSW one.

Valerio Faraoni, Edgard Gunzig, Pasquale Nardone

In recent years, the use of conformal transformation techniques has become widespread in the literature on gravitational theories alternative to general relativity, on cosmology, and on nonminimally coupled scalar fields. Typically, the transformation to the Einstein frame is generated by a fundamental scalar field already present in the theory. In this cont

P. N. Rao, E. A. Schiff, L. Tsybeskov, P. M. Fauchet

We report photocarrier time-of-flight measurements in diode structures made of highly porous crystalline silicon. The corresponding electron and hole drift mobilities are very small compared to homogeneous crystalline silicon. They show two additional signatures of semiclassical transport that are directly limited by a porous geometry: the mobilities are dis

J. C. Chu, C. H. Mak

Constant temperature molecular dynamics simulations were used to study solutions of flexible polyelectrolyte chains at nonzero concentrations with explicit counterions and unscreened coulombic interactions. Counterion condensation, measured via the self-diffusion coefficient of the counterions, is found to increase with polymer concentration, but contrary to

Lincoln Chayes, Kirill Shtengel

We consider certain two-dimensional systems with self--dual points including uniform and disordered $q$-state Potts models. For systems with continuous energy density (such as the disordered versions) it is established that the self--dual point exhibits critical behavior: Infinite susceptibility, vanishing magnetization and power law bounds for the decay of

Neda Safizadeh, Neal Dalal, Kim Griest

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the probability of detecting a planet orbiting the lens is high. We show that adding astrometric information to the photometric micr

Remo Ruffini

The &#34;dyadosphere&#34; (from the Greek word &#34;duas-duados&#34; for pairs) is here defined as the region outside the horizon of a black hole endowed with an electromagnetic field (abbreviated to EMBH for &#34;electromagnetic black hole&#34;) where the electromagnetic field exceeds the critical value, predicted by Heisenberg and Euler for electron-positr

Kelly Holley-Bockelmann, Douglas O. Richstone

We have developed an effective simulation method and applied it to the problem of the accretion of very dense secondary companions by tenuous primaries. We have studied the accretion of objects of varying luminosity ratios, with sizes and densities drawn from the core Fundamental Plane for elliptical galaxies under the assumption that the mass distribution i

I. V. Moskalenko, A. W. Strong

Inverse Compton scattering appears to play a more important role in the diffuse Galactic continuum emission than previously thought, from MeV to GeV energies. We compare models having a large inverse Compton component with EGRET data, and find good agreement in the longitude and latitude distributions at low and high energies. We test an alternative explanat

Herbert Neuberger

The overlap lattice-Dirac operator contains the sign function $ε(H)$. Recent practical implementations replace $ε(H)$ by a ratio of polynomials, $H P_n (H^2)/Q_n (H^2)$, and require storage of $2n+2$ large vectors. Here I show that one can use only 4 large vectors at the cost of executing the core conjugate algorithm twice. The slow-down might be less than b

Martin White

We calculate the higher order moments in a sequence of models where the initial density fluctuations are drawn from a chi^2_nu distribution with a power-law power spectrum. For large values of nu the distribution is approximately gaussian, and we reproduce the values known from perturbation theory. As νis lowered the distribution becomes progressively more n

Evan Scannapieco, Janna Levin, Joseph Silk

We study the effect of a finite topology on the temperature correlations of the cosmic microwave background in a flat universe. Analytic expressions for the angular power spectrum are given for all possible finite flat models. We examine the angular correlation function itself, pointing out visible and discrete features that arise from topology. While observ

F. Gonzalez-Rey, I. Y. Park, M. Rocek

The N=1 superspace generalization of the 3-brane action in 6 dimensions with partially broken N=2 supersymmetry can be constructed using N=1 chiral, complex linear, or real linear superfields. The physical scalars of these multiplets give equivalent descriptions of the two transverse coordinates. The second supersymmetry is realized nonlinearly in all these

D. J. Rowe, B. C. Sanders, H. de Guise

Bases for SU(3) irreps are constructed on a space of three-particle tensor products of two-dimensional harmonic oscillator wave functions. The Weyl group is represented as the symmetric group of permutations of the particle coordinates of these space. Wigner functions for SU(3) are expressed as products of SU(2) Wigner functions and matrix elements of Weyl t

E. M. Terentjev, M. Warner, R. B. Meyer, J. Yamamoto

The solid nematic equivalent of the Fredericks transition is found to depend on a critical field rather than a critical voltage as in the classical case. This arises because director anchoring is principally to the solid rubbery matrix of the nematic gel rather than to the sample surfaces. Moreover, above the threshold field, we find a competition between qu

Duiliu-Emanuel Diaconescu, Gheorghe Ionesei

We consider four dimensional heterotic compactifications on smooth elliptic Calabi-Yau threefolds. Using spectral cover techniques, we study bundle cohomology groups corresponding to charged matter multiplets. The analysis shows that in generic situations, the resulting charged matter spectrum is stable under deformations of the vector bundle.

C. M. Baugh, A. J. Benson, S. Cole, C. S. Frenk

Measurements of galaxy clustering are now becoming possible over a range of redshifts out to z=3. We use a semi-analytic model of galaxy formation to compute the expected evolution of the galaxy correlation function with redshift. We illustrate how the degree of clustering evolution is sensitive to the details of the sample selection. For a fixed apparent ma

Robert de Mello Koch, Radu Tatar

The computation of higher derivative corrections to the low energy effective actions of ${\cal N}=2$ gauge theories is considered. In particular, higher derivative corrections are computed for four dimensional ${\cal N}=2$ super Yang-Mills theory with gauge group SU(2) and $N_f=4$ hypermultiplets in the fundamental representation. The four derivative terms c

M. Cristina Marchetti, Leo Radzihovsky

We study a three dimensional Abrikosov vortex lattice in the presence of an equilibrium concentration of vacancy, interstitial and dislocation loops. Vacancies and interstitials renormalize the long-wavelength bulk and tilt elastic moduli. Dislocation loops lead to the vanishing of the long-wavelength shear modulus. The coupling to vacancies and interstitial

Dietmar Klemm

We present new rotating black brane solutions which solve Einstein's equations with cosmological constant $\Lambda$ in arbitrary dimension $d$. For negative $\Lambda$, the branes naturally appear in AdS supergravity compactifications, and should therefore play some role in the AdS/CFT correspondence. The spacetimes are warped products of a four-dimensional p

M. Kubota, H. Yoshizawa, Y. Moritomo, H. Fujioka

We demonstrate that the half-doped bilayer manganite La_{1}Sr_{2}Mn_{2}O_{7} exhibits CE-type charge-ordered and spin-ordered states below $T_{N, CO}^A = 210$ K and below $T_{N}^{CE} \sim 145$ K, respectively. However, the volume fraction of the CE-type ordering is relatively small, and the system is dominated by the A-type spin ordering. The coexistence of

E. Ghaffarsedeh, J. Quenby

Clustering properties of two samples of X-ray selected AGNs are compared with IR/Optical galactic samples. These are the Einstein Observatory Extended Medium Sensitivity Survey: EMSS; and a sample of 654 ROSAT detected radio quasars. The cosmological dipole moment is calculated for these samples, yielding the values of $b \Omega_o^{-0.6}$. We find this facto

B. Saha

Exact particle-like static, spherically and/or cylindrically symmetric solutions to the equations of interacting scalar and electromagnetic field system have been obtained. We considered Freedman-Robertson-Walker (FRW) space-time as an external homogenous and isotropic gravitational field whereas the homogeneous and anisotropic Universe is given by the G$\dd

Frank Milde, Rudolf A. Römer

Recently, a metal-insulator transition (MIT) was found in the anisotropic Anderson model of localization by transfer-matrix methods (TMM). This MIT has been also investigated by multifractal analysis (MFA) and the same critical disorders $W_c$ have been obtained within the accuracy of the data. We now employ energy level statistics (ELS) to further character

Janna Levin

Black holes cannot be seen directly since they absorb light and emit none, the very quality which earned them their name. We suggest that black holes may be seen indirectly through a chaotic defocusing of light. A black hole can capture light from a luminous companion in chaotic orbits before scattering the light in random directions. To a distant observer,

M. Jinzenji

In this paper, we study the structure of the quantum cohomology ring of a projective hypersurface with non-positive 1st Chern class. We prove a theorem which suggests that the mirror transformation of the quantum cohomology of a projective Calabi-Yau hypersurface has a close relation with the ring of symmetric functions, or with Schur polynomials. With this

Naomi Ota, Kazuhisa Mitsuda, Makoto Hattori, Tatehiro Mihara

We detected an emission line feature at 4 keV in the X-ray spectrum of a sky region including the distant radio galaxy 3C220.1(z=0.62) obtained with ASCA. The line energy is 6.1 - 7.0 keV (90% confidence) in the rest frame of 3C220.1. Within the present statistics, the observed spectra are consistent with two different models; a non-thermal model consisting

A. A. Tsvetkov, D. van der Marel, K. A. Moler, J. R. Kirtley

The Intlerlayer Josephson coupling between the planes of Tl2Ba2CuO6 was determined using infrared spectroscopy and magnetic flux vortex imaging. These methods give a consistent value of $ω_J$= 28 cm$^{-1}$ which, when combined with the condensation energy produces a discrepancy of at least an order of magnitude with deductions based on the interlayer tunneli

Borut Bajc, Goran Senjanovic

We show that the natural presence of flat directions in supersymmetric theories allows for nonrestoration of global and/or gauge symmetries. This has important cosmological consequences for supersymmetric GUTs and in particular it offers a solution of the monopole problem.

S. F. Godijn, S. Moeller, H. Buhmann, L. W. Molenkamp

The thermovoltage of a chaotic quantum dot is measured using a current heating technique. The fluctuations in the thermopower as a function of magnetic field and dot shape display a non-Gaussian distribution, in agreement with simulations using Random Matrix Theory. We observe no contributions from weak localization or short trajectories in the thermopower.

Akira Shimizu, Jun-ichi Inoue

We study the time evolution of the Bose-Einstein condensate of interacting bosons confined in a leaky box, when its number fluctuation is initially (t=0) suppressed. We take account of quantum fluctuations of all modes, including k = 0. We identify a ``natural coordinate'' b_0 of the interacting bosons, by which many physical properties can be simply describ

Alexei V. Tkachenko, Thomas A. Witten

We examine the network of forces to be expected in a static assembly of hard, frictionless spherical beads of random sizes, such as a colloidal glass. Such an assembly is minimally connected: the ratio of constraint equations to contact forces approaches unity for a large assembly. However, the bead positions in a finite subregion of the assembly are underde

V. V. Dodonov, S. S. Mizrahi

We consider a relaxation of a single mode of the quantized field in a presence of one- and two-photon absorption and emission processes. Exact stationary solutions of the master equation for the diagonal elements of the density matrix in the Fock basis are found in the case of completely saturated two-photon emission. If two-photon processes dominate over si

M. D. Lukin, A. B. Matsko, M. Fleischhauer, M. O. Scully

We investigate the quantum properties of fields generated by resonantly enhanced wave mixing based on atomic coherence in Raman systems. We show that such a process can be used for generation of pairs of Stokes and anti-Stokes fields with nearly perfect quantum correlations, yielding almost complete (i.e. 100%) squeezing without the use of a cavity. We discu

Leonid A. Openov, Vladimir F. Elesin

Our numerical calculations on small carbon clusters point to the existence of a metastable three-dimensional eight-atom cluster C$_8$ which has a shape of a six-atom triangular prism with two excess atoms above and below its bases. We gave this cluster the name &#34;prismane&#34;. The binding energy of the prismane equals to 5.1 eV/atom, i.e., is 0.45 eV/ato

Claus O. Wilke

Evolution in changing environments is an important, but little studied aspect of the theory of evolution. The idea of adaptive walks in fitness landscapes has triggered a vast amount of research and has led to many important insights about the progress of evolution. Nevertheless, the small step to time-dependent fitness landscapes has most of the time not be

Silvina Ponce Dawson, Maria Veronica D&#39;Angelo, John E. Pearson

Patterns in reaction-diffusion systems near primary bifurcations can be studied locally and classified by means of amplitude equations. This is not possible for excitable reaction-diffusion systems. In this Letter we propose a global classification of two variable excitable reaction-diffusion systems. In particular, we claim that the topology of the underlyi