February 2000 arXiv papers — page 22

Stephen E. Schneider, James M. Schombert

We examine the Fisher-Tully cz<1000 km/s galaxy sample to determine whether it is a complete and representative sample of all galaxy types, including low surface brightness populations, as has been recently claimed. We find that the sample is progressively more incomplete for galaxies with (1) smaller physical diameters at a fixed isophote and (2) lower HI m

David A. Weintraub, Joel H. Kastner, Dean C. Hines, Raghvendra Sahai

We have used infrared polarimetric imaging with NICMOS to determine precisely the position of the star that illuminates (and presumably generated) the bipolar, pre-planetary reflection nebula RAFGL 2688 (the Egg Nebula). The polarimetric data pinpoint the illuminating star, which is not detected directly at wavelengths less than or equal to 2 microns, at a p

David A. Weintraub, Didier Saumon, Joel H. Kastner, Thierry Forveille

We have obtained 1.64, 1.90 and 2.15 micron narrow-band images of five T Tauri stars in the TW Hya Association (TWA) using the Near-Infrared Camera and Multiobject Spectrometer aboard the Hubble Space Telescope. Most of the T Tauri stars in our study show evidence of absorption by H2O vapor in their atmospheres; in addition, the low-mass brown dwarf candidat

A. A. Chilingarian, G. V. Gharagyozyan, S. S. Ghazaryan, G. G. Hovsepyan

The quality of the MAKET-ANI detector installation in view of the uniformity of the registration efficiency is demonstrated. Based on a data sample collected by the MAKET-ANI array in the period of June 1997 - March 1999, the dependencies of the age parameter on the zenith angle and the EAS size (10^5-10^7) are studied. The variation of the age parameter wit

A. A. Chilingarian, G. V. Gharagyozyan, S. S. Ghazaryan, G. G. Hovsepyan

Using the EAS size spectra measured with the MAKET ANI array on Mt. Aragats, Armenia (3200m a.s.l.) in the range of the shower size 10^5 - 10^7 for different angles-of-incidence, the EAS attenuation length has been determined applying different analysis methods. The analysis is based on a data sample of 2.5*10^6 events collected in the period of June, 97 - A

G. Siemieniec, M. Ostrowski

Some ultra-high energy (UHE) cosmic ray (CR) events may be correlated with the Local Supercluster plane. We consider acceleration of such particles at the large-scale accretion flows of matter towards such plane and/or accretion flows onto galaxy clusters. The formed shocks and the general compression flow are expected to allow for CR diffusive acceleration

Eric C. Ford, Michiel van der Klis, Mariano Mendez, Rudy Wijnands

We measure simultaneously the properties of the energy spectra and the frequencies of the kilohertz quasi-periodic oscillations (QPOs) in fifteen low mass X-ray binaries covering a wide range of X-ray luminosities. In each source the QPO frequencies cover the same range of approximately 300 Hz to 1300 Hz, though the sources differ by two orders of magnitude

A. Manchado, E. Villaver, L. Stanghellini, M. A. Guerrero

We present a statistical analysis of a complete sample (255) of northern planetary nebulae (PNe). Our analysis is based on morphology as a main parameter. The major morphological classes are: round (26 % of the sample), elliptical (61 %), and bipolar (13 %) PNe. About a half of the round and 30 % of the elliptical PNe present multiple shells. Round PNe have

J. C. Guirado, J. M. Marcaide, M. A. Perez-Torres, E. Ros

From 43GHz VLBA observations of the pair of radio sources 1928+738 and 2007+777 we have demonstrated the feasibility of precision phase-delay differential astrometric techniques at millimeter wavelengths. For a pair of sources with 5 degrees separation and high antenna elevations, we have shown that present astrometric models and millimeter arrays are advanc

Hannu Kurki-Suonio

Standard big bang nucleosynthesis (SBBN) has been remarkably successful, and it may well be the correct and sufficient account of what happened. However, interest in variations from the standard picture come from two sources: First, big bang nucleosynthesis can be used to constrain physics of the early universe. Second, there may be some discrepancy between

Feng Yuan

Taking optically thin accretion flows as an example, we investigate the dynamics and the emergent spectra of accretion flows with different outer boundary conditions (OBCs) and find that OBC plays an important role in accretion disk model. This is because the accretion equations describing the behavior of accretion flows are a set of {\em differential} equat

Feng Yuan, Qiuhe Peng, Ju-fu Lu, Jianmin Wang

The influence of the outer boundary condition (OBC) on the dynamics and radiation of optically thin accretion flow is investigated. Bremsstrahlung and synchrotron radiations amplified by Comptonization are taken into account and two-temperature plasma assumption is adopted. The three OBCs we adopted are the temperatures of the electrons and ions and the spec

A. Lazarian, E. Vishniac

Reconnection is the process by which magnetic fields in a conducting fluid change their topology. This process is essential for understanding a wide variety of astrophysical processes, including stellar and galactic dynamos and astrophysical turbulence. To account for solar flares, solar cycles and the structure of the galactic magnetic field reconnection mu

S. C. Gallagher, S. D. Hunsberger, J. C. Charlton, D. Zaritsky

We present HST WFPC2 images of Stephan&#39;s Quintet which encompass three interacting galaxies and their associated tidal features. These deep, three-color (B, V, I) images indicate recent, massive stellar system formation in various regions within the compact group environment. We have identified star cluster candidates (SCC) both within the interacting ga

T. A. Fleming, M. S. Giampapa, J. H. M. M. Schmitt

We have detected an X-ray flare on the very low mass star VB 10 (GL 752 B; M8 V) using the ROSAT High Resolution Imager. VB 10 is the latest type (lowest mass) main sequence star known to exhibit coronal activity. X-rays were detected from the star during a single 1.1-ksec segment of an observation which lasted 22 ksec in total. The energy released by this f

B. V. Vasiliev

The calculations in Thomas-Fermi approximation show that in a gravitational field each cell of ultra dense matter inside celestial bodies obtains a very small positive electric charge. A celestial body is electrically neutral as a whole, because the negative electric charge exists on its surface. On the order of magnitude the positive volume charge is very s

P. Bouwknegt, V. Mathai

In this note we propose that D-brane charges, in the presence of a topologically non-trivial B-field, are classified by the K-theory of an infinite dimensional C^*-algebra. In the case of B-fields whose curvature is pure torsion our description is shown to coincide with that of Witten.

B. Lee Roberts

The status of the muon (g-2) experiment, E821 at the Brookhaven AGS, is given. A new result with a precision of 5 parts per million has been obtained with direct muon injection into the ring and is presented. The theoretical motivation for the experiment, and a discussion of the sensitivity to non-standard model physics is also discussed.

M. V. Kuzmenko

It is shown that the Schrödinger nonrelativistic equation of a system of interacting particles is not a rigorously nonrelativistic equation since it is based on the implicit assumption of finiteness of the interaction propagation velocity. For a system of interacting particles, a fully nonrelativistic nonlinear system of integro-differential equations is pro

Mukul Patel

A comprehensive physical theory explains all aspects of the physical universe, including quantum aspects, classical aspects, relativistic aspects, their relationships, and unification. The central nonlocality principle leads to a nonlocal geometry that explains entire quantum phenomenology, including two-slit experiment, Aspect-type experiments, quantum rand

Matt Visser

In [cond-mat/9906332; Phys. Rev. Lett. 84, 822 (2000)] and [physics/9906038; Phys. Rev. A 60, 4301 (1999)] Leonhardt and Piwnicki have presented an interesting analysis of how to use a flowing dielectric fluid to generate a so-called &#34;optical black hole&#34;. Qualitatively similar phenomena using acoustical processes have also been much investigated. Unf

Amir H. Fatollahi

We argue that different aspects of Light-Front QCD at confined phase can be recovered by the Matrix Quantum Mechanics of D0-branes. The concerning Matrix Quantum Mechanics is obtained from dimensional reduction of pure Yang-Mills theory to 0+1 dimension. The aspects of QCD dynamics which are studied in correspondence with D0-branes are: 1) phenomenological i

David Mateos

The U(1) gauge theory on a D3-brane with non-commutative worldvolume is shown to admit BIon-like solutions which saturate a BPS bound on the energy. The mapping of these solutions to ordinary fields is found exactly, namely non-perturbatively in the non-commutativity parameters. The result is precisely an ordinary supersymmetric BIon in the presence of a bac

Andrew Ferstl, Bayram Tekin, Victor Weir

We study the Einstein-Chern-Simons gravity coupled to Yang-Mills-Higgs theory in three dimensional Euclidean space with cosmological constant. The classical equations reduce to Bogomol&#39;nyi type first order equations in curved space. There are BPS type gauge theory instanton (monopole) solutions of finite action in a gravitational instanton which itself h

Ciprian Acatrinei

The rate of pair production of open strings in general uniform electromagnetic fields is calculated in various space-time dimensions. The corrections with respect to the case of pure electric backgrounds are displayed. In particular, a contribution in the form of a Born-Infeld action is derived and its role in the present context emphasized

Pietro Gianinetti, Alberto Parola

We present a new theoretical approach for the study of the phase diagram of interacting quantum particles: bosons, fermions or spins. In the neighborhood of a phase transition, the expected renormalization group structure is recovered both near the upper and lower critical dimension. Information on the microscopic hamiltonian is also retained and no mapping

F. M. L. Almeida,, Y. A. Coutinho, J. A. Martins Simoes, M. A. B. do Vale

The production and decay of new possible heavy Majorana neutrinos are analyzed in hadronic collisions. New bounds on the mixing of these particles with standard neutrinos are estimated according to a fundamental representation suggested by grand unified models. A clear signature for these Majorana neutrinos is given by same-sign dileptons plus a charged weak

Jordi Miralda-Escude

Spergel & Steinhardt proposed the possibility that the dark matter particles are self-interacting, as a solution to two discrepancies between the predictions of cold dark matter models and the observations: first, the observed dark matter distribution in some dwarf galaxies has large, constant-density cores, as opposed to the predicted central cusps; and sec

G. Ghisellini, D. Lazzati, A. Celotti, M. J. Rees

We calculate the spectrum resulting from the interaction of a fireball with ambient soft photons. These photons are assumed to be produced by the walls of a funnel in a massive star. By parameterizing the radial dependence of the funnel temperature we calculate the deceleration of the fireball self-consistently, taking into account the absorption of high ene

Paul R. Anderson, William A. Hiscock, Brett E. Taylor

The semiclassical Einstein equations are solved to first order in $ε= \hbar/M^2$ for the case of a Reissner-Nordström black hole perturbed by the vacuum stress-energy of quantized free fields. Massless and massive fields of spin 0, 1/2, and 1 are considered. We show that in all physically realistic cases, macroscopic zero temperature black hole solutions do

R. Sekhar Chivukula, Nick Evans, Christian Hoelbling

Precision electroweak data are generally believed to constrain the Higgs boson mass to lie below approximately 190 GeV at 95% confidence level. The standard Higgs model is, however, trivial and can only be an effective field theory valid below some high energy scale characteristic of the underlying non-trivial physics. Corrections to the custodial isospin vi

L. Anton

The time and size distribution of the waves of topplings in the Abelian sandpile model are expressed as the first arrival at the origin distribution for a scale invariant, time inhomogeneous Fokker-Planck equation. Assuming a linear conjecture for the the time inhomogeneity exponent as function of loop erased random walk (LERW) critical exponent, suggested b

Giovanni Losurdo

The operation of an interferometer for gravitational waves detection requires sophisticated feedback controls in many parts of the apparatus. The aim of this lecture is to introduce the types of problems to be faced in this line of research. The attention is focused on the &#34;inertial damping&#34; of the test mass suspension of the VIRGO interferometer (th

Jacob D. Bekenstein, Asaf Oron

We demonstrate, both at the Newtonian and (general) relativistic levels, the existence of a generalization of Kelvin&#39;s circulation theorem (for pure fluids) which is applicable to perfect magnetohydrodynamics. The argument is based on the least action principle for magnetohydrodynamic flow. Examples of the new conservation law are furnished. The new theo

Adriaan M. J. Schakel

It is argued that close to a Coulomb interacting quantum critical point, the interaction between two vortices in a disordered superconducting thin film separated by a distance $r$ changes from logarithmic in the mean-field region to $1/r$ in the region dominated by quantum critical fluctuations. This gives support to the charge-vortex duality picture of the

Nadya A. Smirnova, Norbert Pietralla, Takahiro Mizusaki, Piet Van Isacker

The interrelation between the octupole phonon and the low-lying proton-neutron mixed-symmetry quadrupole phonon in near-spherical nuclei is investigated. The one-phonon states decay by collective E3 and E2 transitions to the ground state and by relatively strong E1 and M1 transitions to the isoscalar 2+ state. We apply the proton-neutron version of the Inter

Anirban Chakraborti, Bikas K. Chakrabarti

If one places N cities randomly on a lattice of size L, we find that the normalized optimal travel distances per city in the Euclidean and Manhattan metrics vary monotonically with the city concentration p. We have studied such optimal tours for visiting all the cities using a branch and bound algorithm, giving exact optimized tours for small system sizes (N

Chao-Shang Huang, Shou Hua Zhu

The differential branching ratio, CP asymmetry and lepton polarization $P_N$ for $B\to ^M X_sτ^+τ^-$ in a CP spotaneously broken two Higgs doublet model are compute d. ^M It is shown that contributions of neutral Higgs bosons to the decay are ^M quite significant when $\tanβ$ is large and $P_N$ can reach five persent.

M. Danilov, R. DeVoe, A. Dolgolenko, G. Giannini

We describe an approach to the study of neutrino masses that combines quantum optics techniques with radiation detectors to obtain unprecedented sensitivity. With it the search for Majorana neutrino masses down to $\sim$10 meV will become accessible. The experimental technique uses the possibility of individually detecting $\rm Ba^+$-ions in the final state

Holger F. Hofmann, Ortwin Hess

The intensity fluctuations of laser light are derived from photon number rate equations. In the limit of short times, the photon statistics for small laser devices such as typical semiconductor laser diodes show thermal characteristics even above threshold. In the limit of long time averages represented by the low frequency component of the noise, the same d

Gerald A. Goldin

An enlarged group G of nonlinear transformations, modeled on the general linear group GL(2,R), leads to a beautiful, apparently unremarked symmetry between the wave function&#39;s phase and the logarithm of its amplitude. Equations Doebner and I earlier proposed are embedded in a wider, natural family of nonlinear time-evolution equations, on which G acts as

J. Leon, J. Julve, P. Pitanga, F. J. de Urries

We introduce a formalism for the calculation of the time of arrival t at a space point for particles traveling through interacting media. We develop a general formulation that employs quantum canonical transformations from the free to the interacting cases to construct t in the context of the Positive Operator Valued Measures. We then compute the probability

J. C. Lemm

Using a new Bayesian method for solving inverse quantum problems, potentials of quantum systems are reconstructed from coordinate measurements in non-stationary states. The approach is based on two basic inputs: 1. a likelihood model, providing the probabilistic description of the measurement process as given by the axioms of quantum mechanics, and 2. additi

Gesche Pospiech

In this article a notion of information is presented which stresses the contextuality of quantum objects and their measurement. Mathematically this is reached by a quantification of the quantum mechanical surplus knowledge which has been introduced by Weizsacker. This new formulation gives insight into relation between single quantum objects and ensembles of

H. Kleinert, B. Van den Bossche

The Van Vleck-Pauli-Morette fluctuation determinant is derived from the global group property of the time evolution amplitude in a continuous formulation of path integrals.

Prabhakar Pradhan, M. P. Anantram, Kang L. Wang

We present a model for quantum computation using n steady 3-level atoms or 3-level quantum dots, kept inside a quantum electro-dynamics (QED) cavity. Our model allows one-qubit operations and the two-qubit controlled-NOT gate as required for universal quantum computation. The n quantum bits are described by two energy levels of each atom/dot. An external las

K. Hallatschek

In full flux-surface computer studies of tokamak edge turbulence, a spectrum of shear flows is found to control the turbulence level and not just the conventional (0,0)-mode flows. Flux tube domains too small for the large poloidal scale lengths of the continuous spectrum tend to overestimate the flows, and thus underestimate the transport. It is shown analy

M. J. Vicente Vacas, E. Oset

Recent experimental results show a large enhancement of the 2 pion emission on the scalar isoscalar channel, which had been predicted by some theoretical estimates. We present here a detailed calculation of the A(pi, 2pi)X process incorporating a microscopic model for the elementary reaction in vacuum, pion-pion final state interaction in the nuclear medium,

D. N. Poenaru, B. Dobrescu, W. Greiner, J. H. Hamilton

We developed a three-center phenomenological model,able to explain qualitatively the recently obtained experimental results concerning the quasimolecular stage of a light-particle accompanied fission process. It was derived from the liquid drop model under the assumption that the aligned configuration, with the emitted particle between the light and heavy fr

O. Costin, J. L. Lebowitz, A. Rokhlenko

We analyze the time evolution of a one-dimensional quantum system with zero range potential under time periodic parametric perturbation of arbitrary strength and frequency. We show that the projection of the wave function on the bound state vanishes, i.e. the system gets fully ionized, as time grows indefinitely.

F. Buccella

We prove that the existence of a homogeneous invariant of degree n for a representation of a semi-simple Lie group guarantees the existence of non-trivial solutions of D_α = 0: these correspond to the maximum value of the square of the invariant divided by the norm of the representation to the n^{th} power.

C. Daskaloyannis

The finite dimensional representations of associative quadratic algebras with three generators are investigated by using a technique based on the deformed parafermionic oscillator algebra. One application on the calculation of the eigenvalues of the two-dimensional superintegrable systems is discussed.

N. V. Ustinov

The compatible expansion in series of solutions of both the equations of P-Q pair at neighborhood of the singular point is obtained in closed form for regular and irregular singularities. The conservation laws of the system of ordinary differential equations to arise from the compatibility condition of the P-Q pair are derived.

Andrei Okounkov

Using techniques from integrable systems, we obtain a number of exact results for random partitions. In particular, we prove a simple formula for correlation functions of what we call the Schur measure on partitions (which is a far reaching generalization of the Plancherel measure, see math.CO/9905032) and also show that these correlations functions are tau-

Robert V. Moody

This article surveys the mathematics of the cut and project method as applied to point sets, called here {\em model sets}. It covers the geometric, arithmetic, and analytical sides of this theory as well as diffraction and the connection with dynamical systems.

Jeong-Yup Lee, Robert V. Moody

The paper studies ways in which the sets of a partition of a lattice in $\RR^n$ become regular model sets. The main theorem gives equivalent conditions which assure that a matrix substitution system on a lattice in $\RR^n$ gives rise to regular model sets (based on $p$-adic-like internal spaces), and hence to pure point diffractive sets. The methods develope

Narcisse Randrianantoanina

Let M be a von Neumann algebra (not necessarily semi-finite). We provide a generalization of the classical Kadec-Pelczynski subsequence decomposition of bounded sequences in L^p[0,1] to the case of the Haagerup L^p-spaces (1\le p<\infty). In particular, we prove that if (ϕ_n)_n is a bounded sequence in the predual M_* of M, then there exist a subsequence (ϕ_

Toshiki Nakashima

We give a parametrization for crystal bases of Demazure modules as a set of lattice points in some convex polytope and we also describe explicitly the extremal vectors as solutions of some system of linear equations.

Uma Iyer

We use the definition of differential operators on noncommutative rings given by V.Lunts and A.Rosenberg to find the differential operators on Azumaya algebras and the Heisenberg algebras.

Bernard Shiffman, Steve Zelditch

The spaces $H^0(M, L^N)$ of holomorphic sections of the powers of an ample line bundle $L$ over a compact Kähler manifold $(M,ω)$ have been generalized by Boutet de Monvel and Guillemin to spaces $H^0_J(M, L^N)$ of `almost holomorphic sections&#39; of ample line bundles over an almost complex symplectic manifold $(M, J, ω)$. We consider the unit spheres $SH^

Everton M. C. Abreu

The non-local regularization is a powerfull method to regularize theories with an action that can be decomposed in a kinetic and an interacting part. Recently it was shown how to regularize the Batalin-Vilkovisky field-antifield formalism of quantization of gauge theories with the non-local regularization. We compute precisely the anomaly of the Chiral Schwi

M. Blagojevic, I. A. Nikolic

We apply Dirac's Hamiltonian approach to study the canonical structure of the teleparallel form of general relativity without matter fields. It is shown, without any gauge fixing, that the Hamiltonian has the generalized Dirac-ADM form, and constraints satisfy all the consistency requirements. The set of constraints involves some extra first class constraint

E. Kazes

Negative norm Hilbert space state vectors can be BRST invariant, we show in a simplified Y-M model, which has gluons and ghost fields only, that such states can be created by starting with gluons only.

Elso Drigo Filho, Regina Maria Ricotta

The formalism of Supersymmetric Quantum Mechanics supplies a trial wave function to be used in the Variational Method. The screened Coulomb potential is analysed within this approach. Numerical and exact results for energy eigenvalues are compared.

V. B. Kopeliovich, B. E. Stern, W. J. Zakrzewski

Static properties of SU(3) multiskyrmions with baryon number up to 6 (classical masses and momenta of inertia) are estimated. The calculations are based on the recently suggested generalization of the SU(2) rational map ansaetze applied to the SU(3) model. Both SU(2) embedded skyrmions and genuine SU(3) solutions are considered, and it is shown that although

P. Di Bari

Cosmology cannot rule out the solution nu_mu <-> nu_s to the atmospheric neutrino data and thus only Earth experiments will be able to give a definitive answer. This conclusion holds when a generation of lepton number is taken into account and one assumes that the sterile neutrino is also slightly mixed with an eV-tau neutrino. This result cannot be spoiled

W. M. Alberico, J. Bernabeu, S. M. Bilenky, W. Grimus

We discuss the problem of solar hep neutrinos originating from the reaction p + 3He -> 4He + e+ + nu and obtain a relation between the astrophysical S-factor of the hep process and the cross section of the process e- + 4He -> 3H + n + nu near threshold. The relation is based on the isotopic invariance of strong interactions. The measurement of the latter cro

Lars Brucher

xloops is a program package that calculates Feynman diagrams by using computer algebra systems. In this paper it is shown which problems to be solved by computer algebra arise during such calculations, and how this problems are handled in the framework of xloops.

Lars Brucher, Rui Santos

The most general Two Higgs Doublet Model potential without explicit CP violation depends on 10 real independent parameters . Excluding spontaneous CP violation results in two 7 parameter models. Although both models give rise to 5 scalar particles and 2 mixing angles, the resulting phenomenology of the scalar sectors is different. If flavour changing neutral

E. Nardi

This talk is based on the article hep-ph/9903517 written in collaboration with Sven Bergmann and Yuval Grossman. An analysis of the effective potential for neutrino propagation in matter, assuming a generic set of Lorentz invariant non-derivative interactions is presented. In addition to vector and axial vector couplings, also tensor interactions can give co

Sheldon Stone

Many measurements are necessary in the program of studying mixing, CP violation and rare decays of b and c quarks. These measurements require large numbers of B^o, B_s, B^- and D^{*+} hadrons. Fortunately, copius production of particles containing b and c quarks will occur at Tevatron and the LHC. The crucial measurements are described here, as well as the d

Shi-Lin Zhu

We first calculate the binding energy, the pionic and electromagnetic couping constants of the lowest lying p-wave heavy baryon doublet $Λ_{c1}$, $Λ_{c1}^*$ in the leading order of the heavy quark expansion. Then we calculate the two-body decay widths with these couplings and compare our results with other approaches. Our results are $Γ(Λ_{c1}\to Σ_c π, Σ_c

O. Lalakulich, E. A. Paschos, M. Flanz

We study the mixing of elementary and composite particles. In quantum field theory the mixing of composite particles originates in the couplings of the constituent quarks and for neutrinos in self-energy diagrams. In the event that the incoming and outgoing neutrinos have different masses, the self-energy diagrams vanish because energy is not conserved but t

Amir Levinson

The curvature radiation produced by particles accelerating near the event horizon of a spinning supermassive black hole, threaded by externally supported magnetic field lines is considered. It is shown that light nuclei suffer catastrophic curvature losses that limit the maximum energy they can attain to values well below that imposed by the maximum potentia

C. Blöchinger, H. Fraas

We investigate associated production of selectrons and the lightest neutralino (LSP) in the process e^- + gamma --> neutralino_1 + selectron_{L/R} with the selectron subsequently decaying into an electron and the LSP. Total cross sections and various polarization asymmetries are calculated for photons produced by Compton backscattering of a polarized laser b

F. Karsch, E. Laermann, A. Peikert

We calculate the pressure in QCD with two and three light quarks on a lattice of size 16^3x4 using tree level improved gauge and fermion actions. We argue that for temperatures T > 2T_c systematic effects due to the finite lattice cut-off and non-vanishing quark masses are below 15% in this calculation and give an estimate for the continuum extrapolated pres

B. Hoeneisen, C. Marín

We consider the minimal extension of the Standard Model with three generations of massive neutrinos that mix. We then determine the parameters of the model that satisfy all experimental constraints.

Alcides Garat, Richard H. Price

Initial data for black hole collisions are commonly generated using the Bowen-York approach based on conformally flat 3-geometries. The standard (constant Boyer-Lindquist time) spatial slices of the Kerr spacetime are not conformally flat, so that use of the Bowen-York approach is limited in dealing with rotating holes. We investigate here whether there exis

Sukanta Bose, Archana Pai, Sanjeev Dhurandhar

We formulate the data analysis problem for the detection of the Newtonian waveform from an inspiraling compact-binary by a network of arbitrarily oriented and arbitrarily distributed laser interferometric gravitational wave detectors. We obtain for the first time the relation between the optimal statistic and the magnitude of the network correlation vector,

E. Chassande-Mottin, S. Dhurandhar

We propose an adaptive denoising scheme for poorly modeled non-Gaussian features in the gravitational wave interferometric data. Preliminary tests on real data show encouraging results.

S. Frasca

Five cryogenic resonant gravitational antennas are now in operation. This is the first time that such a large number of high sensitive antennas are taking data and an agreement on data exchange has been signed by the responsible groups. The data exchanged will consist essentially in lists of &#39;&#39;candidate events&#39;&#39;. In this paper the procedure u

A. Gammal, T. Frederico, Lauro Tomio, F. Kh. Abdullaev

Considering the static solutions of the D-dimensional nonlinear Schroedinger equation with trap and attractive two-body interactions, the existence of stable solutions is limited to a maximum critical number of particles, when D is greater or equal 2. In case D=2, we compare the variational approach with the exact numerical calculations. We show that, the ad

Benjamin Painter, R. P. Behringer

We experimentally examine the dynamics of two-particle collisions occuring on a surface. We find that in two-particle collisions a standard coefficient of restitution model may not capture crucial dynamics of this system. Instead, for a typical collision, the particles involved slide relative to the substrate for a substantial time following the collision; d

Harry Westfahl, Dirk K. Morr

We present a theory for inelastic neutron scattering (INS) and nuclear magnetic resonance (NMR) experiments in the pseudo-gap regime of the underdoped high-$T_c$ cuprates. We show that superconducting phase fluctuations greatly affect the temperature and frequency dependence of the spin-susceptibility, $χ&#39;&#39;$, probed by both experimental techniques. T

Mark J. Bowick, Alex Travesset

The fluctuations of two-dimensional extended objects membranes is a rich and exciting field with many solid results and a wide range of open issues. We review the distinct universality classes of membranes, determined by the local order, and the associated phase diagrams. After a discussion of several physical examples of membranes we turn to the physics of

Baruch Horovitz, Pierre Le Doussal

A 3D layered system of charges with logarithmic interaction parallel to the layers and random dipoles is studied via a novel variational method and an energy rationale which reproduce the known phase diagram for a single layer. Increasing interlayer coupling leads to successive transitions in which charge rods correlated in N>1 neighboring layers are nucleat

J. Hales, A. Zhukov, R. Roy, M. I. Dykman

We report a direct experimental observation and provide a theory of the distribution of trajectories along which a fluctuating system moves over a potential barrier in escape from a metastable state. The experimental results are obtained for a semiconductor laser with optical feedback. The distribution of paths displays a distinct peak, which shows how the e

Robert A Smith, Vinay Ambegaokar

We calculate the first-order perturbative correction to the transition temperature $T_c$ in a superconductor with both non-magnetic and magnetic impurities. We do this by first evaluating the correction to the effective potential, $Ω(Δ)$, and then obtain the first-order correction to the order parameter, $Δ$, by finding the minimum of $Ω(Δ)$. Setting $Δ=0$ f

Leticia F. Cugliandolo, Jose Luis Iguain

We reproduce the results of non-resonant spectral hole-burning experiments with fully-connected (equivalently infinite-dimensional) glassy models that are generalizations of the mode-coupling approach to nonequilibrium situations. We show that an ac-field modifies the integrated linear response and the correlation function in a way that depends on the amplit

Barbara Drossel, Mehran Kardar

We study the interplay between surface roughening and phase separation during the growth of binary films. Already in 1+1 dimension, we find a variety of different scaling behaviors depending on how the two phenomena are coupled. In the most interesting case, related to the advection of a passive scalar in a velocity field, nontrivial scaling exponents are ob

Thereza Paiva, Raimundo R dos Santos

Charge density waves in the Hubbard chain are studied by means of finite-temperature Quantum Monte Carlo simulations and Lanczos diagonalizations for the ground state. We present results both for the charge susceptibilities and for the charge structure factor at densities ρ=1/6 and 1/3; for ρ=1/2 (quarter filled) we only present results for the charge struct

N. K. Kuzmenko, V. M. Mikhajlov, S. Frauendorf

The response of $nm$-size spherical superconducting clusters to a magnetic field is studied for the canonical ensemble of electrons in a single degenerate shell. For temperatures close to zero, the discreteness of the electronic states causes a step like destruction of the pair correlations with increasing field strength, which shows up as peaks in the susce

Hiroya Nakao

Multi-scaling properties of one-dimensional truncated Levy flights are studied. Due to the broken self-similarity of the distribution of jumps, they are expected to possess multi-scaling properties in contrast to the ordinary Levy flights. We argue this fact based on a smoothly truncated Levy distribution, and derive the functional form of the scaling expone

Mar Serrano, Pep Español

The GENERIC structure allows for a unified treatment of different discrete models of hydrodynamics. We first propose a finite volume Lagrangian discretization of the continuum equations of hydrodynamics through the Voronoi tessellation. We then show that a slight modification of these discrete equations has the GENERIC structure. The GENERIC structure ensure

Munetaka Sasaki, Koji Nemoto

We introduce magnetization to the Multi-layer Random Energy Model which has a hierarchical structure, and perform Monte Carlo simulation to observe the behavior of ac-susceptibility. We find that this model is able to reproduce three prominent features of spin glasses, i.e., memory effect, rejuvenation and chaos effect, which were found recently by various e

R. Kajimoto, Y. Oohara, M. Kubota, H. Yoshizawa

We have investigated the charge and spin ordering in Nd{1/3}Sr{2/3}FeO{3} with neutron diffraction technique. This sample undergoes a charge ordering transition accompanying charge disproportionation of 2Fe4+ -> Fe3+ + Fe5+. We measured the superlattice reflections due to the charge and spin ordering, and confirmed that charges and spins order simultaneously

Munetaka Sasaki, Koji Nemoto

We study the effect of temperature shift on aging phenomena in the Random Energy Model (REM). From calculation on the correlation function and simulation on the Zero-Field-Cooled magnetization, we find that the REM satisfies a scaling relation even if temperature is shifted. Furthermore, this scaling property naturally leads to results obtained in experiment

G. M. Madejski, P. T. Zycki, C. Done, A. Valinia

We report the Rossi X-ray Timing Explorer observations of the heavily absorbed Seyfert 2 galaxy NGC 4945, which confirm the large column density of the absorber, corresponding to the optical depth to Thomson scattering of about 2.4. The hard X-ray flux (8-30 keV) measured by us is rapidly variable with a large amplitude, on time scales of a day or less. This

Solange V. Ramirez, Kristen Sellgren, John S. Carr, Suchitra C. Balachandran

We present measurements of [Fe/H] for six M supergiant stars and three giant stars within 0.5 pc of the Galactic Center (GC) and one M supergiant star within 30 pc of the GC. The results are based on high-resolution (lambda / Delta lambda =40,000) K-band spectra, taken with CSHELL at the NASA Infrared Telescope Facility.We determine the iron abundance by det

K. P. Dere, A. Vourlidas, Prasad Subramanian

We present a brief overview of LASCO and EIT observations of CMEs. We discuss CME energetics, the relation of CMEs to streamers and conclude with some insights into the source regions of CMEs.