March 1999 arXiv papers — page 10

Leon Balents, Matthew P. A. Fisher, Chetan Nayak

As discovered in the quantum Hall effect, a very effective way for strongly-repulsive electrons to minimize their potential energy is to aquire non-zero relative angular momentum. We pursue this mechanism for interacting two-dimensional electrons in zero magnetic field, by employing a representation of the electrons as composite bosons interacting with a Che

Erik van Nimwegen, James P. Crutchfield, Martijn Huynen

We introduce and analyze a general model of a population evolving over a network of selectively neutral genotypes. We show that the population's limit distribution on the neutral network is solely determined by the network topology and given by the principal eigenvector of the network's adjacency matrix. Moreover, the average number of neutral mutant

Micheal S. Berger, Biswajoy Brahmachari

We study a set of textures giving rise to correct masses and mixings of the charged fermions in the context of leptogenesis. The Dirac neutrino texture pattern is assumed to be identical with the up quark texture. The heavy Majonana neutrino mass matrix is obtained by inverting the type-I see-saw formula and using the neutrino masses and mixings required by

S. I. Manayenkov

We explore the possibility whether the gluon helicity distribution $ΔG(x)$ can be extracted from a comparison of experimental data on the longitudinal spin-spin asymmetry $A_{LL}$ in $γp$ diffractive deep inelastic scattering with calculations performed within the framework of perturbative QCD (pQCD). The data could be obtained at the future HERA collider in

George B. Rybicki, Abraham Loeb

In Loeb & Rybicki (1999; paper I) it was shown that before reionization, the scattering of \lya photons from a cosmological source might lead to a fairly compact ($\sim 15''$) \lya halo around the source. Observations of such halos could constrain the properties of the neutral intergalactic medium (IGM), and in particular yield the cosmological densi

A. Cavaliere, D. Malquori

The BL Lac population is set apart from the rest of the active galactic nuclei by a number of peculiar features, including remarkably little signs of cosmological evolution. We focus on this feature, and take hint from the observations to reconsider extraction of the primary energy from a Kerr hole via the Blandford-Znajek (BZ) process; in fact, we stress ho

M. V. Chizhov, S. T. Petcov

A new effect of total neutrino conversion is possible when neutrino propagates through multi-layer medium of nonperiodic constant density layers. The effect can take place in the oscillations in the Earth of the Earth-core-crossing solar and atmospheric neutrinos.

Ian I. Kogan

We discuss a possible relation between singletons in $AdS$ space and logarithmic conformal field theories at the boundary of $AdS$. It is shown that the bulk Lagrangian for singleton field (singleton dipole) induces on the boundary the two-point correlation function for logarithmic pair. Bulk interpretation of mixing between logarithmic operator $D$ and zero

Fiorenzo Bastianelli, Roberto Zucchini

We determine from 11D supergravity the quadratic bulk action for the physical bosonic fields relevant for the computation of correlation functions of normalized chiral operators in D=6, N=(0,2) and D=3, N=8 supersymmetric CFT in the large N limit, as dictated by the AdS/CFT duality conjecture.

David A. Buote

We analyze the ASCA spectra accumulated within ~100 kpc radii of 12 of the brightest groups of galaxies. Upon fitting isothermal models (1T) jointly to the ASCA SIS and GIS spectra we obtain fits for most groups that are of poor or at best marginal quality and give very sub-solar metallicities similar to previous studies, <Z> = 0.29 +/- 0.12 Z_sun. Two-tempe

Per Dahlqvist

We apply periodic orbit theory to study the asymptotic distribution of escape times from an intermittent map. The dynamical zeta function exhibits a branch point which is associated with an asymptotic power law escape. By an analytic continuation technique we compute a zero of the zeta function beyond its radius of convergence leading to a pre-asymptotic exp

J. Troost

We find topological defect solutions to the equations of motion of a generalised Higgs model with antisymmetric tensor fields. These solutions are direct higher dimensional analogues of the Nielsen-Olesen vortex solution for a gauge field in four dimensions.

A. Delgado, M. Quiros

We analyze the implications of electroweak and strong coupling unification in a very general class of models extending the minimal supersymmetric standard model in $4+p$ dimensions $(p\geq 0)$. In general, electroweak precision data require the presence of large extra dimensions (low compactification scales, $M_c$) and/or low unification scale, $M_U$. In par

J. Leon, M. Manna

The discrete multiscale analysis for boundary value problems in nonlinear discrete systems leads to a first order discrete modulational instability above a threshold amplitude for wave numbers beyond the zero of group velocity dispersion. Applied to the electrical lattice [Phys. Rev. E, 51 (1995) 6127 ], this acurately explains the experimental instability a

Markus Hormess, Georg Junker

We present explicit closed-form expressions for the general group-theoretical factor appearing in the alpha-topology of a high-temperature expansion of SO(n)-symmetric lattice models. This object, which is closely related to 6j-symbols for the most degenerate representation of SO(n), is discussed in detail.

P. Desgrolard, L. Jenkovszky, A. Lengyel, F. Paccanoni

We parametrize the small x, singlet component of the proton structure function F_2 by powers and logarithms of 1/x for discrete values of Q^2 between 0.2 and 2000 GeV^2, and compare these parametrizations by applying the criterion of minimal $χ^2$. The obtained values of the fitted parameters may be used to study the evolution of F_2 in Q^2 and/or in discrim

Chun Liu

Within the framework of gauge mediated supersymmetry breaking, we consider an electroweak symmetry breaking pattern in which there is no conventional $μ$ term. The pattern is made appealing through realizing it as low energy effective description of a supersymmetric Yang-Mills theory which is of confinement. Phenomenological implications are discussed.

G. Sguazzoni

The ALEPH Silicon Vertex Detector features an optical fibre laser system to monitor its mechanical stability. The operating principle and the general performance of the laser system are described. The experience obtained during 1997 and 1998 operations confirms the important role that such a system can have with respect to the detector alignment requirements

Jon Links

An extension of the supersymmetric U model for correlated elctrons is given and integrability is established by demonstrating that the model can be constructed through the Quantum Inverse Scattering Method using an R-matrix without the difference property. Some general symmetry properties of the model are discussed and from the Bethe ansatz solution an expre

Michael A. Nowak, Joern Wilms

Models for the characteristically soft X-ray spectrum of the compact X-ray source V1498 Aql (=4U 1957+11) have ranged from optically thick Comptonization to multicolor accretion disk models. We critically examine the X-ray spectrum of V1408 Aql via archival Advanced Satellite for Cosmology and Astrophysics (ASCA) data, archival Roentgensatellit (ROSAT) data,

A. A. Pastor, V. Dobrosavljevic

A model of spinless interacting electrons in presence of randomness is examined using an extended dynamical mean-field formulation. When the interaction strength is large as compared to the Fermi energy, a low temperature glassy phase is identified, which in our formulation corresponds to a replica-symmetry breaking instability. The glassy phase is character

Mark S. Sherwin, Atac Imamoglu, Thomas Montroy

A quantum computer is proposed in which information is stored in the two lowest electronic states of doped quantum dots (QDs). Many QDs are located in a microcavity. A pair of gates controls the energy levels in each QD. A Controlled Not (CNOT) operation involving any pair of QDs can be effected by a sequence of gate-voltage pulses which tune the QD energy l

T. Tsuchida, H. Ujino, M. Wadati

A system of semi-discrete coupled nonlinear Schrödinger equations is studied. To show the complete integrability of the model with multiple components, we extend the discrete version of the inverse scattering method for the single-component discrete nonlinear Schrödinger equation proposed by Ablowitz and Ladik. By means of the extension, the initial-value pr

G. P. Berman, D. F. V. James, R. J. Hughes, M. S. Gulley

The realization of a paradigm chaotic system, namely the harmonically driven oscillator, in the quantum domain using cold trapped ions driven by lasers is theoretically investigated. The simplest characteristics of regular and chaotic dynamics are calculated. The possibilities of experimental realization are discussed.

V. V. Balandin, N. I. Golubeva

The equations of classical spin-orbit motion can be extended to a Hamiltonian system in 9-dimensional phase space by introducing a coupled spin-orbit Poisson bracket and a Hamiltonian function. After this extension and by establishing connections between initial and extended systems it becomes possible to apply the methods of the theory of Hamiltonian system

Franz Lemmermeyer

This is an updated version of ANT-0166. Generalizing results of Stroeker and Top we show that the 2-ranks of the Tate-Shafarevich groups of the elliptic curves $y^2 = (x+k)(x^2+k^2)$ can become arbitrarily large. We also present a conjecture on the rank of the Selmer groups attached to rational 2-isogenies of elliptic curves.

Franz Lemmermeyer

In a series of articles published in the C.R. Paris more than a century ago, T. Pépin announced a list of ``theorems&#39;&#39; concerning the solvability of diophantine equations of the type $ax^4 + by^4 = z^2$. In this article, we show how to prove these claims using the structure of 2-class groups of imaginary quadratic number fields. We will also look at

Dino J. Lorenzini

Let $M \in M_n (\mathbb Z)$ denote any matrix. Thinking of $M$ as a linear map $M:{\mathbb Z}^n \to {\mathbb Z}^n$, we denote by ${\Image}(M)$ the $\mathbb Z$-span of the column vectors of $M$. Let $e_1, ..., e_n,$ denote the standard basis of ${\mathbb Z}^n$, and let $E_{ij}: = e_i - e_j$, $ (i \neq j)$. In this article, we are interested in the group ${\ma

Saharon Shelah, Otmar Spinas

Let C denote any of the following cardinal characteristics of Boolean algebras: incomparability, spread, character, pi-character, hereditary Lindelof number, hereditary density. It is shown to be consistent that there exists a sequence <B_i:i<kappa> of Boolean algebras and an ultrafilter D on kappa such that C(prod_{i<kappa}B_i/D)<|prod_{i<kappa}C(B_i)/D|. T

Chongying Dong, Ching Hung Lam, Hiromichi Yamada

For vertex operator algebra V_{\sqrt{2}A_l} associated to the even lattice \sqrt{2}A_l which is \sqrt{2} times root lattice of type A_l, it was shown by Dong-Li-Maosn-Norton that the Virasoro vector is a sum of l+1 mutually orthogonal conformal vectors with central charges c_i=1-6/(i+2)(i+3) for i=1,...,l and c_{l+1}=2l/(l+3) and the subalgebra T generated b

Sakae Fuchino, Heike Mildenberger, Saharon Shelah, Peter Vojtas

We show that in the aleph_2-stage countable support iteration of Mathias forcing over a model of CH the complete Boolean algebra generated by absolutely divergent series under eventual dominance is not isomorphic to the completion of P(omega)/fin. This complements Vojtas&#39; result, that under cf(c)=p the two algebras are isomorphic

Timothy J. Hodges

The coefficients of certain operators on $V\otimes V$ can be constructed using generating functions. Necessary and sufficient conditions are given for some such operators to satisfy the Yang-Baxter equation. As a corollary we obtain a simple, direct proof that the Cremmer-Gervais R-matrices satisfy the Yang-Baxter equation. This approach also clarifies Cremm

Sergey Finashin

The topology of the orbit space, $Y$, for the action of the complex conjugation on a complex surface, $X$, defined over reals, is studied. I give a criterion for blow-up stable triviality of $Y$ (which implies vanishing of its Seiberg-Witten invariants). The main result concerns the double planes branched along the complexification of reducible real curves w

Scott Crass

Recently, Peter Doyle and Curt McMullen devised an iterative solution to the fifth degree polynomial. At the method&#39;s core is a rational mapping of the Riemann sphere with the icosahedral symmetry of a general quintic. Moreover, this map posseses &#34;reliable&#34; dynamics: for almost any initial point, its trajectory converges to one of the periodic cy

Bernard Leclerc, Jean-Yves Thibon

We give an explicit criterion for the irreducibility of some induction products of evaluation modules of affine Hecke algebras of type A. This allows to describe the form of the singularities of the trigonometric R-matrix associated to any evaluation module of U_v(sl^_N).

Wolf P. Barth

An effective divisor D on a smooth (compact complex) surface X is called even, if its class $[D] \in H^2(X,\Z)$ is divisible by 2. D may be assumed reduced w.l.o.g. Then D being even is equivalent to the existence of a double cover $Y \to X$ branched exactly over D. The aim of this note is to study arrangements of $n \leq 10$ distinct lines on a smooth quart

Hitoshi Murakami

A weight system is defined from the (multivariable) Conway potential function. We also show that it can be calculated recursively by using five axioms.

Scott Crass, Peter Doyle

Recently, Peter Doyle and Curt McMullen devised an iterative solution to the fifth degree polynomial. At the method&#39;s core is a rational mapping of the Riemann sphere with the icosahedral symmetry of a general quintic. Moreover, this map posseses &#34;reliable&#34; dynamics: for almost any initial point, the its trajectory converges to one of the periodi

Ely Kerman

In this paper we produce a lower bound for the number of periodic orbits of certain Hamiltonian vector fields near Bott-nondegenerate symplectic critical submanifolds. This result is then related to the problem of finding closed orbits of the motion of a charged low energy particle on a Riemannian manifold under the influence of a magnetic field

Steven R. Finch

This is a brief survey of certain constants associated with random lattice models, including self-avoiding walks, polyominoes, the Lenz-Ising model, monomers and dimers, ice models, hard squares and hexagons, and percolation models.

C. Grojean, J. Mourad

We determine, to the first order in the radius of Anti-de-Sitter, the realisation of the $OSp(6,2|2)$ superconformal algebra on vector fields. We then calculate, to this order, the superspace metric describing the background of $AdS_7\times S^4$. The coordinates we work with are adapted to a 6+5 splitting of the eleven dimensional superspace. Finally, we ded

Zygmunt Lalak, Stéphane Lavignac, Hans Peter Nilles

Anomalous U(1) gauge symmetries in type II orientifold theories show some unexpected properties. In contrast to the heterotic case, the masses of the gauge bosons are in general of order of the string scale even in the absence of large Fayet-Iliopoulos terms. Despite this fact, the notion of heterotic-type II orientifold duality remains a useful concept, alt

D. Chruscinski

We propose a simple method to reduce a general p-form electrodynamics with respect to the standard Gauss constraints. The canonical structure of the reduced theory displays a p-dependent sign which makes the essential difference between theories with different parities of p. This feature was observed recently in the corresponding quantization condition for p

Shijong Ryang

By working with the free energy for the type II supergravity near-horizon solution of N coincident non-extremal Dp-branes we study the transitions among the non-conformal Dp-brane system, the perturbative super Yang-Mills theory and a certain system associated with M theory. We derive a relation between this free energy and the action of a Dp-brane probe in

Victor Chernyak

The asymptotic behaviour of the vacuum energy density, ${\bar E}(θ)$, at $θ\ra \pm i \infty$ is found out. A new interpretation and a qualitative discussion of the ${\bar E}(θ)$ behaviour are presented. It is emphasized that the vacuum is doubly degenerate at $θ=π$, and the quark electric string can terminate on the domain wall interpolating between these tw

S. Heinemeyer, W. Hollik, G. Weiglein

A compact approximation formula for the mass of the lightest neutral CP-even Higgs boson, m_h, in the Minimal Supersymmetric Standard Model (MSSM) is derived from the diagrammatic two-loop result for m_h up to O(alpha alpha_s). By analytically expanding the diagrammatic result the leading logarithmic and non-logarithmic as well as the dominant subleading con

Paresh Malde, Robin G. Stuart

The complete O(N_f alpha^2) weak contributions to the muon lifetime, denoted as Delta r^(2), are calculated in the MS-bar renormalization scheme. These come from 2-loop Feynman diagrams containing a loop formed by complete generations of massless fermions. They form an independent, gauge-invariant set of corrections that, because of the large number of light

A. Bartl, T. Gajdosik, W. Porod, P. Stockinger

We analyze the effects of CP-violating phases on the electric dipole moment (EDM) of electron and neutron in the constrained minimal supersymmetric model. We find that the phases phi_μ and phi_{A_0} have to be strongly correlated, in particular for small values of the SUSY mass parameters. We calculate the neutron EDM in two different models, the Quark-Parto

N. V. Mikheev, A. Ya. Parkhomenko, L. A. Vassilevskaya

An interaction of a pseudoscalar particle with two photons induced by an external electromagnetic field is used to study the photon decay $γ\to γa$ where a is a pseudoscalar particle associated with the Peccei-Quinn U(1) symmetry. The field-induced axion emission by photon is analyzed as a possible source of energy losses by astrophysical objects.

Oliver Klapp, Patrick Langefeld

This is a summary of the latest results of the DELPHI Collaboration on the properties of identified quark and gluon jets. It covers the measurement of the fragmentation functions of gluons and quarks and their scaling violation behaviour as well as an analysis of the scale dependence of the multiplicities in gluon and quark jets. Further, a precision measure

A. V. Anisovich, V. V. Anisovich, D. V. Bugg, V. A. Nikonov

We calculate partial widths for the decays a_0(980)\toγγand f_0(980)\toγγunder the assumption that a_0(980) and f_0(980) are members of the basic 1^3P_0 q\bar q nonet. The results are in a reasonable agreement with data thus giving an argument for a q\bar q origin of these mesons. We also calculate the γγpartial widths for the other scalar mesons, members of

F. Larios, M. A. Perez, C. -P. Yuan

We update the constraints on anomalous dimension four $\tbw$ and $\ttz$ couplings by using CLEO $b \ra s γ$ and LEP/SLC precision $Z$-pole data. It is found that the data imposes very stringent bounds on them. Moreover, the $2 σ$ pull from SM predictions of $A_{LR}$(hadrons), $A_b$ and $A_{FB}$(b) have little chance of being explained by the strongly constra

Markus A. Luty, John Terning

We review recent work on realistic models that break supersymmetry dynamically and give rise to composite quarks and leptons, all in a single sector. These models have a completely natural suppression of flavor-changing neutral currents, and the hierarchy of Yukawa couplings is explained by the dimensionality of composite states. The generic signatures are u

S. Scherer, S. A. Bass, M. Belkacem, M. Bleicher

Nonequilibrium models (three-fluid hydrodynamics, UrQMD, and quark molecular dynamics) are used to discuss the uniqueness of often proposed experimental signatures for quark matter formation in relativistic heavy ion collisions from the SPS via RHIC to LHC. It is demonstrated that these models -- although they do treat the most interesting early phase of the

Kenneth Lane

We present hadron collider production rates for the lightest color-singlet technihadrons in a simple ``straw-man&#39;&#39; model of low-scale technicolor. These rates are presented in a way to facilitate their encoding in PYTHIA. This document is a companion to my paper, ``Technihadron Production and Decay in Low-Scale Technicolor&#39;&#39;.

Asish Satpathy

The working principle and performance of the BELLE particle identification device (PID), based on a hybrid system consisting of an array of high precision scintillator Time of Flight and silica Aerogel Counters, is discussed. The performances achieved in the beam tests are satisfactory and Monte Carlo tests of meeting physics objectives of BELLE are promisin

The WA102 Collaboration, D. Barberis et al

A partial wave analysis of the centrally produced pi0pi0 channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f0(980), f0(1300) and f0(1500) in the the S-wave. and the f2(1270) is observed dominantly in the D0-wave. In addition, there is evidence f

The WA102 Collaboration, D. Barberis et al

A partial wave analysis of the centrally produced pi+pi- channel has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found. Evidence is found for the f0(980), f0(1300), f0(1500) and fJ(1710) with J = 0 in the the S-wave. The rho(770) is observed dominantly in the P0-wave and the f2(1270)

The WA102 Collaboration, D. Barberis et al

A partial wave analysis of the centrally produced K+K- and K0K0 channels has been performed in pp collisions using an incident beam momentum of 450 GeV/c. An unambiguous physical solution has been found in each channel. The striking feature is the observation of peaks in the S-wave corresponding to the f0(1500) and fJ(1710) with J = 0. The D-wave shows evide

Krishnaswamy Gounder

Recent electroweak results from the CDF and D0 Collaborations at the Fermilab Tevatron Collider are presented. After a brief description of the \D0 measurements of W/Z production cross sections, W width, W mass and W \to τνdecays, the CDF result on W(pT) distribution is outlined. The comprehensive search for anomalous gauge couplings by \D0 in 1992-96 data i

D. V. Ahluwalia

The extreme smallness of both the Planck length, on the one side, and the ratio of the gravitational to the electrical forces between, say, two electrons, on the other side has led to a widespread belief that the realm of quantum gravity is beyond terrestrial experiments. A series of classical and quantum arguments are put forward to dispel this view. It is

R. Michael Jones

An estimate for the classical action for a Bianchi VI_h homogeneous spatially closed cosmology is presented as a function of b, a parameter of the model that is proportional to the relative rotation of the average inertial frame and the bulk of matter in the universe. It is assumed (through the equation of state) that a relativistic early universe is followe

J. Butterfield, C. J. Isham

We survey some philosophical aspects of the search for a quantum theory of gravity, emphasising how quantum gravity throws into doubt the treatment of spacetime common to the two `ingredient theories&#39; (quantum theory and general relativity), as a 4-dimensional manifold equipped with a Lorentzian metric. After an introduction, we briefly review the concep

Manoelito M. de Souza, Robson N. Silveira

In a previous work General Relativity has been presented as a microscopic theory of finite and discrete point-like fields that we associate to a classical description of gravitons. The standard macroscopic continuous field is retrieved as an average-valued field through an integration over these gravitons. Here we discuss extreme alternative (the Gauss&#39;s

Sergei M. Kopeikin

Localized astronomical sources like a double stellar system, rotating neutron star, or a massive black hole at the center of the Milky Way emit periodic gravitational waves. For a long time only a far-zone contribution of gravitational fields of the localized sources (plane-wave-front approximation) were a matter of theoretical analysis. We demonstrate how t

R. Casadio, B. Harms

Charged black holes, both spherically symmetric and rotating, in the low energy limit of string theory (Einstein-Maxwell-dilaton theory) are compared to analogous geometries in pure general relativity. We describe various physical differences and investigate some experiments which can distinguish between the two theories. In particular we discuss the gyro-ma

Eric Baird

Olum (PRL 81 3567-3570, 1998) has defined &#34;superluminality&#34; as the ability of a signal path to carry information faster than any neighbouring signal path, and has suggested that this requires a negative energy-density. However, this condition can be created without exotic matter if we are only sending information along the delivery path in one partic

Tapas Kumar Das

In this work the impact of the Internet culture on standard mainstream societies has been analyzed. After analytically establishing the fact that the Net can be viewed as a pan-societal superstructure which supports its own distinct culture, an ethnographic analysis is provided to find out the key aspects of this culture. The elements of this culture which h

A. J. Masters, P. B. Warren

Kinetic theory of dissipative particle dynamics is developed in terms of a Boltzmann pair collision theory. The kinetic transport coefficients are computed from explicit collision integrals and compared favourably with detailed simulations. Previous theory is found to correspond to a weak scattering limit, or Vlasov theory, and previously reported discrepanc

D. Munzar, C. Bernhard, A. Golnik, J. Humlicek

The spectra of the far-infrared c-axis conductivity of underdoped YBCO crystals exhibit dramatic changes of some of the phonon peaks when going from the normal to the superconducting state. We show that the most striking of these anomalies can be naturally explained by changes of the local fields acting on the ions arising from the onset of inter- and intra-

Brad Jacobsen, Karl Saunders, Leo Radzihovsky, John Toner

We show that smectic liquid crystals confined in_anisotropic_ porous structures such as e.g.,_strained_ aerogel or aerosil exhibit two new glassy phases. The strain both ensures the stability of these phases and determines their nature. One type of strain induces an ``XY Bragg glass&#39;&#39;, while the other creates a novel, triaxially anisotropic ``m=1 Bra

Wannapong Triampo, T. J. Newman

This work is a continuation of our previous investigation of binary data corruption due to a Brownian agent [T. J. Newman and W. Triampo, preprint cond-mat/9811237]. We extend our study in three main directions which allow us to make closer contact with real bistable systems. These are i) a detailed analysis of two dimensions, ii) the case of competing agent

M. Krech

The influence of a thermodynamic constraint on the critical finite-size scaling behavior of three-dimensional Ising and XY models is analyzed by Monte-Carlo simulations. Within the Ising universality class constraints lead to Fisher renormalized critical exponents, which modify the asymptotic form of the scaling arguments of the universal finite-size scaling

P. Prelovsek, P. Horsch

The consequences of the non-Drude charge response in the normal state of cuprates and the effect of the layered structure on electron-energy loss spectra are investigated, both for experiments in the transmission and the reflection mode. It is shown that in the intermediate doping regime the plasmon resonance has to be nearly critically damped as a result of

Hsuan-Yi Chen, David Jasnow

We study the hydrodynamics of a freely-standing smectic-A film in the isothermal, incompressible limit theoretically by analyzing the linearized hydrodynamic equations of motion with proper boundary conditions. The dynamic properties for the system can be obtained from the response functions for the free surfaces. Permeation is included and its importance ne

K. A. Moler, John. R. Kirtley

Here we reply to Farid&#39;s comment.

Behnam Farid

We comment on the work by Moler, et al., [Science 279, 1193 (1998)] concerning determination of the c-axis penetration depth in the single-layer compound Tl-2201 through measuring the magnetic flux due to isolated interlayer Josephson vortices.

I. Mirebeau, M. Hennion, H. Casalta, H. Andres

We performed high resolution diffraction and inelastic neutron scattering measurements of Mn_{12}-acetate. Using a very high energy resolution, we could separate the energy levels corresponding to the splitting of the lowest S multiplet. Data were analyzed within a single spin model (S=10 ground state), using a spin Hamiltonian with parameters up to 4^{th} o

K. V. Kavokin

Spin dynamics in a quantum well made of diluted-magnetic semiconductor is studied theoretically. The exchange interaction of the ensemble of localized spins with two-dimensional heavy-hole gas is shown to affect time evolution of the spin system in an in-plane magnetic field. The Larmor frequency of localized spins is reduced under influence of an oscillatin

Ryo Tamura, Masaru Tsukada

Electron transmission and wave functions through junctions with a pair of a pentagonal defect and a heptagonal defect connecting two metallic carbon nanotubes are analyzed by the analytical calculation with the effective mass equation. The energy region $|E| < E_c$ is considered where the channel number is kept to two. Close relation between the transmission

M. V. N. Murthy, R. Shankar

We give a formulation of the single particle occupation probabilities for a system of identical particles obeying fractional exclusion statistics of Haldane. We first derive a set of constraints using an exactly solvable model which describes an ideal exclusion statistics system and deduce the general counting rules for occupancy of states obeyed by these pa

Jysoo Lee, Joel Koplik

We use Stokesian Dynamics simulations to study the microscopic motion of particles suspended in fluids passing through porous media. We construct model porous media with fixed spherical particles, and allow mobile ones to move through this fixed bed under the action of an ambient velocity field. We first consider the pore scale motion of individual suspended

Karin A. Dahmen, David R. Nelson, Nadav M. Shnerb

We review localization with non-Hermitian time evolution as applied to simple models of population biology with spatially varying growth profiles and convection. Convection leads to a constant imaginary vector potential in the Schroedinger-like operator which appears in linearized growth models. We illustrate the basic ideas by reviewing how convection affec

Hsien-chung Kao, Chia-Hung Chang, Xiao-Gang Wen

We study a class of Abelian quantum Hall (QH) states which are topologically unstable (T-unstable). We find that the T-unstable QH states can have a phase transition on the edge which causes a binding between electrons and reduces the number of gapless edge branches. After the binding transition, the single-electron tunneling into the edge gains a finite ene

M. H. Hettler, M. Mukherjee, M. Jarrell, H. R. Krishnamurthy

We recently introduced the dynamical cluster approximation(DCA), a new technique that includes short-ranged dynamical correlations in addition to the local dynamics of the dynamical mean field approximation while preserving causality. The technique is based on an iterative self-consistency scheme on a finite size periodic cluster. The dynamical mean field ap

K. Kobayashi, T. Mizokawa, A. Ino, J. Matsuno

We have performed x-ray absorption spectroscopy (XAS) and x-ray photoemission spectroscopy (XPS) studies of single crystal Ba_{1-x}K_{x}BiO_{3} (BKBO) covering the whole composition range $0 \leq x \leq 0.60$. Several features in the oxygen 1\textit{s} core XAS spectra show systematic changes with $x$. Spectral weight around the absorption threshold increase

Masami Ouchi, Toru Yamada, Hideaki Kawai, Kouji Ohta

We investigate expected sub-mm emission and dust properties of the Lyman Break Galaxies (LBGs) in the Hubble Deep Field (HDF). The SCUBA Deep Survey (Hughes et al., 1998) provides an upper limit of the 850 micron flux densities of the LBGs. With this constraint, we argue that a typical ultra-violet to far-infrared spectral shape of the high-redshift LBGs is

Stephane Courteau, Sidney van den Bergh

New data on the membership of the Local Group, in conjunction with new and improved radial velocity data, are used to refine the derivation of the motion of the Sun relative to the Local Group (hereafter LG). The Sun is found to be moving with a velocity of Vbulk = 306 \pm 18 km/s, towards an apex at l = 99 \pm 5 and b = -4 \pm 4 degrees. This agrees very we

Stephane Courteau

This is an announcement of a new database of structural properties for 304 late-type (Sb-Sc) spiral galaxies drawn from the UGC catalogue. These data were compiled from the kinematic and photometric studies of Courteau (1996, 1997), and are made available to the community via the Canadian Astronomy Data Centre. The data base contains redshift information and

Travis A. Rector, John T. Stocke, Eric S. Perlman

Many properties of BL Lacs have become explicable in terms of the &#34;relativistic beaming&#34; hypothesis whereby BL Lacs are FR-1 radio galaxies viewed nearly along the jet axis. However, a possible problem with this model is that a transition population between beamed BL Lacs and unbeamed FR-1s has not been detected. A transition population of &#34;low-l

Richard C. Henry

A new determination of the upper limit to the cosmic diffuse background radiation, at ~110 nm, of 300 photons s-1 cm-2 sr-1 nm-1, is placed in the context of diffuse background measurements across the entire electromagnetic spectrum, including new optical, infrared, visible, and gamma-ray background measurements. The possibility that observed excess diffuse

B. Mobasher, L. Cram, A. Georgakakis, A. Hopkins

Using a recently completed survey of faint (sub-mJy) radio sources, selected at 1.4 GHz, a dust-free estimate of the local star formation rate (SFR) is carried out. The sample is 50% complete to 0.2 mJy, with over 50% of the radio sources having optical counterparts brighter than R = 21.5. Spectroscopic observations of 249 optically identified radio sources

R. A. Flores, H. Quintana, M. J. Way

We present results of simple N-body simulations that strengthen the suggestion that A3266 is composed of two subunits of comparable mass that have recently merged. Both the real cluster and the N-body dark-matter cluster show mixed signals of substructure under statistical tests. However, in a decidedly non-statistical approach allowed by the wide-area cover

I. H. Stairs, A. G. Lyne, F. Camilo, N. P. F. McKay

The Parkes multibeam pulsar survey is a high-frequency, fast-sampled survey of the Galactic Plane, expected to discover at least 500 new pulsars. To date, over 200 pulsars have been found, including several young pulsars and at least one with a very high magnetic field. Seven of the new stars are in binary systems; this number includes one probable double-ne

A. W. Longbottom, G. J. Rickard, I. J. D. Craig, A. D. Sneyd

We use a numerical nonlinear multigrid magnetic relaxation technique to investigate the generation of current sheets in three-dimensional magnetic flux braiding experiments. We are able to catalogue the relaxed nonlinear force-free equilibria resulting from the application of deformations to an initially undisturbed region of plasma containing a uniform, ver

S. Y. Sazonov, R. A. Sunyaev

Electron scattering induces a polarization in the cosmic microwave background (CMB) signal measured in the direction of a galaxy cluster due to the presence of a quadrupole component in the CMB temperature distribution. Measuring the polarization towards distant clusters provides the unique opportunity to observe the evolution of the CMB quadrupole at modera

Philippe Andre, Derek Ward-Thompson, Mary Barsony

The last decade has witnessed significant advances in our observational understanding of the earliest stages of low-mass star formation. The advent of sensitive receivers on large radio telescopes such as the JCMT and IRAM 30m MRT has led to the identification of young protostars at the beginning of the main accretion phase (`Class 0&#39; objects), and has m

Anthony Challinor

The Ehlers-Ellis 1+3 formulation of covariant hydrodynamics, when supplemented with covariant radiative transport theory, gives an exact, physically transparent description of the physics of the cosmic microwave background radiation (CMB). Linearisation around a Friedmann-Robertson-Walker (FRW) universe provides a very direct and seamless route through to th

R. I. Hynes, P. Roche, P. A. Charles, M. J. Coe

We present optical and infrared observations of the soft X-ray transient (SXT) XTE J2012+381 and identify the optical counterpart with a faint red star heavily blended with a brighter foreground star. The fainter star is coincident with the radio counterpart and appears to show weak H alpha emission and to have faded between observations. The RXTE/ASM lightc

Donald F. Figer, Ian S. McLean, Mark Morris

We present near-infrared photometry and K-band spectra of newly-identified massive stars in the Quintuplet Cluster, one of the three massive clusters projected within 50 pc of the Galactic Center. We find that the cluster contains a variety of massive stars, including more unambiguously identified Wolf-Rayet stars than any cluster in the Galaxy, and over a d