May 2003 arXiv papers — page 3

Yuichi Terashima, Andrew S. Wilson

We present the results of two Chandra observations (separated by 1 year) of the population of X-ray sources in the spiral galaxy M51 (NGC 5194 and NGC 5195). 113 X-ray sources have been detected in an 8'.4x8'.4 region. Nine and 28 sources have luminosities exceeding 10^39 erg/s (ULXs) and 10^38 erg/s in the 0.5-8 keV band, respectively, assuming they

Masahiro Kawasaki, Fuminobu Takahashi

The recent observation of the cosmic microwave background anisotropy by the WMAP confirmed that the lower multipoles are considerably suppressed. From the standpoint of the cosmic variance, it is nothing but a statistical accident. Alternatively, one can attribute the deficit of fluctuation on the large scale to the cosmic history, which might be explained i

Tetsuya Shiromizu, Kazuya Koyama, Sumitada Onda, Takashi Torii

We consider a D-brane coupled with gravity in type IIB supergravity on S^5 and derive the effective theory on the D-brane in two different ways, that is, holographic and geometrical projection methods. We find that the effective equations on the brane obtained by these methods coincide. The theory on the D-brane described by the Born-Infeld action is not lik

Kazunori Takenaga

It is pointed out that the existence of bare mass terms for matter fields changes gauge symmetry patterns through the Hosotani mechanism. As a demonstration, we study an SU(2) gauge model with massive adjoint fermions defined on $M^4\otimes S^1$. It turns out that the vacuum structure changes at certain critical values of $mL$, where $m~(L)$ stands for the b

Sebastien Lepine, R. Michael Rich, Michael M. Shara

We report the discovery of LSR1610-0040, a previously unreported r=17.5 star with a very high proper motion mu=1.46"/yr. This very cool star (b-i=6.3) is found to have a peculiar spectrum that does not fit into the standard sequence of late-M dwarfs and L dwarfs. Rather, the spectrum is more typical of an ultra-cool subdwarf, with weak bands of TiO and n

T. Yoshida, M. Terasawa, T. Kajino, K. Sumiyoshi

We study the nucleosyntheses of the light elements 7Li and 11B and the r-process elements in Type II supernovae from the point of view of supernova neutrinos and Galactic chemical evolution. We investigate the influence of the luminosity and average energy (temperature) of supernova neutrinos on these two nucleosynthesis processes. Common models of the total

Shiping Feng, Tianxing Ma, Jihong Qin

We develop a partial charge-spin separation fermion-spin theory implemented the gauge invariant dressed holon and spinon. In this novel approach, the physical electron is decoupled as the gauge invariant dressed holon and spinon, with the dressed holon behaviors like a spinful fermion, and represents the charge degree of freedom together with the phase part

Shun-ichiro Koh

The question of whether the BEC is a necessary condition of the Meissner effect is examined. The electromagnetic susceptibility of a charged Bose gas with short-range repulsion is studied using the perturbation theory with respect to the repulsive force. With decreasing temperature, the Bose-statistical coherence grows, and prior to the BEC phase the suscept

Heath Gerhardt, John Watrous

In this paper we study continuous-time quantum walks on Cayley graphs of the symmetric group, and prove various facts concerning such walks that demonstrate significant differences from their classical analogues. In particular, we show that for several natural choices for generating sets, these quantum walks do not have uniform limiting distributions, and ar

F. Herbut

It is shown that for each mixed state there exists a Schmidt (super state vector) decomposition in terms of Hermitian operators. Its utilization for finding all twins is illustrated in full detail in the case of the two spin-one-half-particle states with maximally disordered subsystems (mixtures of Bell states).

Marlan O. Scully, Vitaly V. Kocharovsky, Alexey Belyanin, Edward Fry

When ground state atoms are accelerated through a high Q microwave cavity, radiation is produced with an intensity which can exceed the intensity of Unruh acceleration radiation in free space by many orders of magnitude. The cavity field at steady state is described by a thermal density matrix under most conditions. However, under some conditions gain is pos

Stefan Weigert

A quantum mechanical search procedure to determine the real zeros of a polynomial is introduced. It is based on the construction of a spin observable whose eigenvalues coincide with the zeros of the polynomial. Subsequent quantum mechanical measurements of the observable output directly the numerical values of the zeros. Performing the measurements is the on

Garry Bowen, Rajagopal Nagarajan

In Shannon information theory the capacity of a memoryless communication channel cannot be increased by the use of feedback from receiver to sender. In this paper the use of classical feedback is shown to provide no increase in the unassisted classical capacity of a memoryless quantum channel when feedback is used across non-entangled input states, or when t

Peter Holland

It is proved by a functional method that the conventional expression for the Dirac current is the only conserved 4-vector implied by the Dirac equation that is a function of just the quantum state. The demonstration is extended to derive the unique conserved currents implied by the coupled Maxwell-Dirac equations and the Klein-Gordon equation. The uniqueness

G Filewood

Extension of the formalism of Q.M. to resolve mathematical anomalies in the structure of anti-unitary operators; implications for vacuum structure and spin-statistics arising from an analysis applied to the S.H.O. Outline of the derived properties of the S.M. Higgs boson.

Tsuyoshi Nishioka, Toshio Hasegawa, Hirokazu Ishizuka

Multiphoton state in quantum cryptography decreases its security. Key disclosing with universal quantum cloning machine (UQCM) is considered in explicit manner. Although UQCM cannot make perfect clones, there is some invariant quantity between the original photon and the imperfect clones. The invariant quantity, the direction of Stokes parameters, tells us t

Arcangelo Rossi

It is known that there is no possibility of transmitting information without a certain amount of energy. This is arbitrarily small in Classical Physics, due to the continuous nature of the energy parameter, while one cannot reduce that amount below Planck's energy quanta in Quantum Physics. In short, one cannot send less than a photon from a place to ano

S. M. Iftiquar, Kiyomi Sakai, Masahiko Tani, Bambang Widiyatmoko

We report on an attempt to generate highly stable continuous terahertz (THz) wave by using optical frequency comb (OFC). About 10-nm wide OFC has been generated through a deep phase modulation of a 852 nm laser line in lithium niobate crystal cavity. The multiple optical modes (side bands) of the OFC, which are equally separated from each other by the modula

S. M. Iftiquar, Haruhiko Ito, Akifumi Takamizawa, Motoichi Ohtsu

Optical near field has been generated by Laguarre-Gaussian doughnut beam on inner surface of "atom funnel". The resulting optical near field has been measured with the help of fiber probe and a consequent effect on cold atoms- released from MOT, has been estimated. Atoms with temperature less than 10 micro_kelvin can be reflected by the optical near

Jerzy Kijowski, Marcin Koscielecki

It is shown that the total energy of the static "field + particle" system, defined in the framework of classical, renormalized electrodynamics of particles and fields, depends in an unstable way upon the field boundary data. It is argued that this phenomenon may be also an origin of the unstable dynamical behaviour of the system (i.e. existence of &#

C. Giunti

It is shown that, in spite of the appearances, the standard expression for the oscillation probability of ultrarelativistic neutrinos is Lorentz invariant.

Michael B. Partensky

A simple two charge system, one charge being suspended on a spring, exhibits complex behavior including bistability, hysteresis and catastrophic response to gradual variation of the external parameters. We discuss these complex features (that can be related, e.g., to membrane electroporation and voltage gating of ion channels) using only high school physics.

V. L. Kalashnikov, E. Sorokin, I. T. Sorokina

The Kerr-lens mode locking ability and the ultrashort pulse characteristics are analyzed numerically for the Cr-doped ZnTe, ZnSe, ZnS active media. The advantages of these materials for the femtosecond lasing within 2 - 3 $μ$m spectral range are demonstrated.

P. Navratil, W. E. Ormand

The ab initio no-core shell model (NCSM) is extended to include a realistic three-body interaction in calculations for p-shell nuclei. The NCSM formalism is reviewed and new features needed in calculations with three-body forces are discussed in detail. We present results of first applications to 6,7Li, 6He, 7,8,10Be, 10,11,12B, 12N and 10,11,12,13C using th

G. E. Brown, Mannque Rho

We propose that effective field theories for nuclei and nuclear matter comprise of "double decimation": (1) the chiral symmetry decimation (CSD) and (2) Fermi liquid decimation (FLD). The Brown-Rho scaling recently identified as the parametric dependence intrinsic in the "vector manifestation" of hidden local symmetry theory of Harada and Yam

M. Tohyama, P. Schuck

An extended time-dependent Hartree-Fock theory, known as the time-dependent density-matrix theory (TDDM), is solved as a time-independent eigenvalue problem for low-lying $2^+$ states in $^{24}$O to understand the foundation of the rather successful time-dependent approach. It is found that the calculated strength distribution of the $2^+$ states has physica

M. Tohyama, P. Schuck

Necessary conditions that the spurious state associated with the translational motion and its double-phonon state have zero excitation energy in extended RPA (ERPA) theories which include both one-body and two-body amplitudes are investigated using the small amplitude limit of the time-dependent density-matrix theory (STDDM). STDDM provides us with a quite g

V. Koch, A. Majumder

We discuss the question of equilibriation in heavy ion collisions and how it can be addressed in experiment

Fritz Gesztesy, Karl Unterkofler, Rudi Weikard

We extend Halphen's theorem which characterizes the solutions of certain $n$th-order differential equations with rational coefficients and meromorphic fundamental systems to a first-order $n \times n$ system of differential equations. As an application of this circle of ideas we consider stationary rational algebro-geometric solutions of the $\kdv$ hiera

Fritz Gesztesy, Karl Unterkofler, Rudi Weikard

Combining theorems of Halphen, Floquet, and Picard and a Frobenius type analysis, we characterize rational, meromorphic simply periodic, and elliptic KdV potentials. In particular, we explicitly describe the proper extension of the Calogero--Moser locus associated with these three classes of algebro-geometric solutions of the KdV hierarchy with special empha

Attila Andai

The theory of monotone Riemannian metrics on the state space of a quantum system was established by Denes Petz in 1996. In a recent paper he argued that the scalar curvature of a statistically relevant - monotone - metric can be interpreted as an average statistical uncertainty. The present paper contributes to this subject. It is reasonable to expect that s

Jorge Cortes, Francesco Bullo

This paper discusses dynamical systems for disk-covering and sphere-packing problems. We present facility location functions from geometric optimization and characterize their differentiable properties. We design and analyze a collection of distributed control laws that are related to nonsmooth gradient systems. The resulting dynamical systems promise to be

Jason Starr

For a hypersurface in complex projective space $X\subset \PP^n$, we investigate the singularities and Kodaira dimension of the Kontsevich moduli spaces $\Kbm{0,0}{X,e}$ parametrizing rational curves of degree $e$ on $X$. If $d+e \leq n$ and $X$ is a general hypersurface of degree $d$, we prove that $\Kbm{0,0}{X,e}$ has only canonical singularities and we con

Daniel Birmajer

The Amitsur-Levitski theorem asserts that $M_n(F)$ satisfies a polynomial identity of degree $2n$. (Here, $F$ is a field and $M_n(F)$ is the algebra of $n \times n$ matrices over $F$). It is easy to give examples of subalgebras of $M_n(F)$ that do satisfy an identity of lower degree and subalgebras of $M_n(F)$ that satisfy no polynomial identity of degree $\

Alberto Elduque

The centralizer algebra of the action of the unitary group on the real tensor powers of its natural module, is described by means of a modification in the multiplication of the signed Brauer algebras. The relationships of this algebra with the invariants for U(n), and with the decomposition of the above tensor powers into irreducible modules, is considered.

K. J. Linde

It is shown that a certain representation of the Heisenberg type Krichever-Novikov algebra gives rise to a state field correspondence that is quite similar to the vertex algebra structure of the usual Heisenberg algebra. Finally a definition of Krichever-Novikov type vertex algebras is proposed and its relation to vertex algebras is discussed.

Daniel Azagra, Juan Ferrera, Fernando Lopez-Mesas

We establish some perturbed minimization principles, and we develop a theory of subdifferential calculus, for functions defined on Riemannian manifolds. Then we apply these results to show existence and uniqueness of viscosity solutions to Hamilton-Jacobi equations defined on Riemannian manifolds.

Oliver T. Dasbach, Tao Li

We show that if a knot has a minimal spanning surface that admits certain Gabai disks, then this knot has Property P. As one of the applications we extend and simplify a recent result of Menasco and Zhang that closed 3-braid knots have Property P. Other applications are given.

Ethan Berkove, Daniel Juan-Pineda, Qin Lu

We prove that the Fibered Isomorphism Conjecture of T. Farrell and L. Jones holds for various mapping class groups. In many cases, we explicitly calculate the lower algebraic K-groups, showing that they do not always vanish.

Matthias Beck, Sinai Robins, Shelemyahu Zacks

Higher-dimensional Dedekind sums are defined as a generalization of a recent 1-dimensional probability model of Dilcher and Girstmair to a d-dimensional cube. The analysis of the frequency distribution of marked lattice points leads to new formulae in certain special cases, and to new bounds for the classical Dedekind sums. Upper bounds for the generalized D

Vladimir N. Ivanov

We introduce interpolation analogues of Schur Q-functions - the multiparameter Schur Q-functions. We obtain for them several results: a combinatorial formula, generating functions for one-row and two-rows functions, vanishing and characterization properties, a Pieri-type formula, a Nimmo-type formula (a relation of two Pfaffians), a Giambelli-Schur-type Pfaf

C. S. Rajan

We show that a tensor product of irreducible, finite dimensional representations of a simple Lie algebra over a field of characteristic zero, determines the individual constituents uniquely. This is analogous to the uniqueness of prime factorisation of natural numbers.

Marta M. Asaeda, Jozef H. Przytycki, Adam S. Sikora

The Kauffman-Harary conjecture states that for any reduced alternating diagram K of a knot with a prime determinant p, every non-trivial Fox p-coloring of K assigns different colors to its arcs. We generalize the conjecture by stating it in terms of homology of the double cover of S^3 branched along a link. In this way we extend the scope of the conjecture t

Eric J. Rawdon, Jonathan K. Simon

We establish a fundamental connection between smooth and polygonal knot energies, showing that the Minimum Distance Energy for polygons inscribed in a smooth knot converges to the Moebius Energy of the smooth knot as the polygons converge to the smooth knot. However, the polygons must converge in a ``nice'' way, and the energies must be correctly reg

Xiang Tang, Alan Weinstein

We define a C*-algebraic quantization of constant Dirac structures on tori, which extends the standard quantization of Poisson structures. We prove that Dirac structures in the same orbit of a natural action of O(n,n|Z) give rise to Morita equivalent algebras, completing and extending a theorem of Rieffel and Schwarz.

Vadim Kostrykin, Konstantin A. Makarov, Alexander K. Motovilov

Let A and C be self-adjoint operators such that the spectrum of A lies in a gap of the spectrum of C and let d>0 be the distance between the spectra of A and C. We prove that under these assumptions the sharp value of the constant c in the condition ||B||<cd guaranteeing the existence of a (bounded) solution to the operator Riccati equation XA-CX+XBX=B^* is

Andrei O. Barvinsky, Alexander Yu. Kamenshchik, Andreas Rathke, Claus Kiefer

We discuss the theory and phenomenology of the interplay between the massless graviton and its massive Kaluza-Klein modes in the Randall-Sundrum two-brane model. The equations of motion of the transverse traceless degrees of freedom are derived by means of a Green function approach as well as from an effective nonlocal action. The second procedure clarifies

E. Ivanov

The AdS/CFT transformation relates two nonlinear realizations of (super)conformal groups: their realization in the appropriate field theories in Minkowski space with a Goldstone dilaton field and their realization as (super)isometry groups of AdS (super)spaces. It exists already at the classical level and maps the field variables and space-time coordinates o

B. Basu-Mallick, Tanaya Bhattacharyya, Diptiman Sen

We find that localized quantum N-body soliton states exist for a derivative nonlinear Schrodinger (DNLS) model within an extended range of coupling constant (ξ_q) given by 0 < | ξ_q | < 1/\hbar \tan [π/(N-1)]. We also observe that soliton states with both positive and negative momentum can appear for a fixed value of ξ_q. Thus the chirality property of class

Kazuo Ghoroku, Nobuhiro Uekusa

We have examined the localization of gauge bosons on the three-brane embedded in 5D bulk space-time, and we find two kinds of branes on which both graviton and gauge bosons can be trapped. One is the dS brane with a positive cosmological constant, and the other is the one with zero cosmological constant or 4D Minkowski brane. Then, which brane is realized wo

E. A. Calzetta, B. L. Hu

Following the paradigm of Boltzmann-BBGKY we propose a correlation entropy (of the nth order) for an interacting quantum field, obtained by `slaving&#39; (truncation with causal factorization) of the higher (n+1 th) order correlation functions in the Schwinger-Dyson system of equations. This renders an otherwise closed system effectively open where dissipati

Oliver Brein, Wolfgang Hollik

The cross section for the production of the lightest neutral Higgs boson in association with a high-pT hadronic jet, calculated in the framework of the minimal supersymmetric standard model (MSSM), is presented. The expectations for the hadronic cross section at the Large Hadron Collider are discussed using reasonable kinematical cuts. In particular the cont

Evgeny Shabalin

The amplitudes of the $K^{\pm} \to 3π$ and $K \to 2π$ decays are expressed in terms of different combinations of one and the same set of CP-conserving and CP-odd parameters. Extracting the magnitudes of these parameters from the data on $K \to 2π$ dacays, we estimate an expected CP-odd difference between the values of the slope parameters $g^+$ and $g^-$ of

V. V. Rubish

Based on the Dirac approach we have developed the relativistic vision of the WKB method for centrally symmetrical potential with mixed Lorenz structure. We have obtained relativistic wavefunctions of light quark and the new rule of quantization containing the spin-orbit interaction. These gives us the possibility of finding the energy levels and decay width

S. Pakvasa

It is shown how deviations of neutrino flavor mix from the canonical 1 : 1 : 1 in high energy astrophysical neutrinos can provide evidence for neutrino decays with lifetimes as long as $10^4 s/eV$.

T. S. Biro, B. Mueller, S. G. Matinyan

We review the idea of chaotic quantization, based on the dynamics of classical lattice gauge systems as well as on non-abelian plasma physics in the infrared limit. The basic conjecture between Planck constant and properties of the five dimensional classical theory (h=aT) is demonstrated numerically for the U(1) lattice gauge group.

I. Alexandrov, A. Amorim, E. Badescu, M. Barczyk

Trigger and data acquisition (TDAQ) systems for modern HEP experiments are composed of thousands of hardware and software components depending on each other in a very complex manner. Typically, such systems are operated by non-expert shift operators, which are not aware of system functionality details. It is therefore necessary to help the operator to contro

M. Diwan

This document describes the design of the accelerator and target systems for the AGS Super Neutrino Beam Facility. Under the direction of the Associate Laboratory Director Tom Kirk, BNL has established a Neutrino Working Group to explore the scientific case and facility requirements for a very long baseline neutrino experiment. Results of a study of the phys

F. Acernese, F. Barone, R. De Rosa, R. Esposito

The analysis of data coming from interferometric antennas for gravitational waves detection may require a huge amount of computing power. The usual approach to the detection strategy is to set-up computer farms able to perform several tasks in parallel, exchanging data through network links. In this paper a new computation strategy is presented. This strateg

Martin L. Purschke

PHENIX is one of two large experiments at Brookhaven National Laboratory&#39;s Relativistic Heavy-Ion Collider (RHIC). At the time of the conference, the PHENIX experiment was about halfway through the 2003 run, which started in January 2003. In preparation for the run, the PHENIX data acquisition, the computing infrastructure, and the software have undergon

M. Iacovacci, S. Catalanotti, P. Creti, G. Liguori

The ARGO-YBJ experiment, currently under construction at the Yangbaijing Laboratory (4300 m a.s.l.), consists of a single layer of about 2000 Resistive Plate Chambers (RPCs) for a total instrumented area of about 6700 m^2. The digital read-out, performed by means of pick-up electrodes 6.7 X 62 cm^2 (&#39;strips&#39;), allows one to measure the particle numbe

S. Mastroianni, A. Aloisio, S. Catalanotti, S. Cavaliere

The ARGO-YBJ experiment has been designed to detect air shower events over a large size scale and with an energy threshold of a few hundreds GeV. The building blocks of the ARGO-YBJ detector are single-gap Resistive Plate Counters (RPCs). The trigger logic selects the events on the basis of their hit multiplicity. Inclusive triggers as well as dedicated trig

David N. Brown, representing the BaBar Collaboration

BaBar has recently deployed a new event data format referred to as the Mini. The Mini uses efficient packing and aggressive noise suppression to represent the average reconstructed BaBar event in under 7 KBytes. The Mini packs detector information into simple transient data objects, which are then aggregated into roughly 10 composite persistent objects per e

Raül Vera

The problem of describing isolated rotating bodies in equilibrium in General Relativity has so far been treated under the assumption of the circularity condition in the interior of the body. For a fluid without energy flux, this condition implies that the fluid flow moves only along the angular direction, i.e. there is no convection. Using this simplificatio

D. Pomarede, M. Virchaux

The Persint program is designed for the three-dimensional representation of objects and for the interfacing and access to a variety of independent applications, in a fully interactive way. Facilities are provided for the spatial navigation and the definition of the visualization properties, in order to interactively set the viewing and viewed points, and to

R. Bartoldus, G. Dubois-Felsmann, Y. Kolomensky, A. Salnikov

The configuration database is one of the vital systems in the BaBar on-line system. It provides services for the different parts of the data acquisition system and control system, which require run-time parameters. The original design and implementation of the configuration database played a significant role in the successful BaBar operations since the begin

Gilles Daniel

An analytical formula for the probability distribution of stock-market returns, derived from the Heston model assuming a mean-reverting stochastic volatility, was recently proposed by Dragulescu and Yakovenko in Quantitative Finance 2002. While replicating their results, we found two significant weaknesses in their method to pre-process the data, which cast

M. Marzolla, V. Melloni

Monitoring large clusters is a challenging problem. It is necessary to observe a large quantity of devices with a reasonably short delay between consecutive observations. The set of monitored devices may include PCs, network switches, tape libraries and other equipments. The monitoring activity should not impact the performances of the system. In this paper

Baden Hughes

The UQ Flint Archive houses the field notes and elicitation recordings made by Elwyn Flint in the 1950&#39;s and 1960&#39;s during extensive linguistic survey work across Queensland, Australia. The process of digitizing the contents of the UQ Flint Archive provides a number of interesting challenges in the context of EMELD. Firstly, all of the linguistic dat

Marcus Hutter

Solomonoff unified Occam&#39;s razor and Epicurus&#39; principle of multiple explanations to one elegant, formal, universal theory of inductive inference, which initiated the field of algorithmic information theory. His central result is that the posterior of his universal semimeasure M converges rapidly to the true sequence generating posterior mu, if the l

Alexander Barvinok, Sandor P. Fekete, David S. Johnson, Arie Tamir

We consider the traveling salesman problem when the cities are points in R^d for some fixed d and distances are computed according to geometric distances, determined by some norm. We show that for any polyhedral norm, the problem of finding a tour of maximum length can be solved in polynomial time. If arithmetic operations are assumed to take unit time, our

A. Kuklov, N. Prokof&#39;ev, B. Svistunov

Depending on the Hamiltonian parameters, two-component bosons in an optical lattice can form at least three different superfluid phases in which both components participate in the superflow: a (strongly interacting) mixture of two miscible superfluids (2SF), a paired superfluid vacuum (PSF), and (at a commensurate total filling factor) the super-counter-flui

Yeong E. Kim, Alexander L. Zubarev

The lowest order constrained variational method [Phys. Rev. Lett. 88, 210403 (2002)] has been generalized for a dilute (in the sense that the range of interatomic potential is small compared with inter-particle spacing) uniform gas of bosons near the Feshbach resonance using the multi-channel zero-range potential model. The method has been applied to Na (F=1

Supriya Krishnamurthy, R. Rajesh, Oleg Zaboronski

We study a d-dimensional system of diffusing particles that on contact either annihilate with probability 1/(q-1) or coagulate with probability (q-2)/(q-1). In 1-dimension, the system models the zero temperature Glauber dynamics of domain walls in the q-state Potts model. We calculate P(m,t), the probability that a randomly chosen lattice site contains a par

Valter L. Libero, K. Capelle

We analyse the ground-state energy and correlation energy of the Heisenberg model as a function of spin, both in the ferromagnetic and in the antiferromagnetic case, and in one, two and three dimensions. First, we present a comparative analysis of known expressions for the ground-state energy $E_0(S)$ of {\it homogeneous} Heisenberg models. In the one-dimens

Thomas Alderweireld, Jean Nuyts

The technique of Padé Approximants, introduced in a previous work, is applied to extended recent data on the distribution of variations of interest rates compiled by the Federal Reserve System in the US. It is shown that new power laws and new scaling laws emerge for any maturity not only as a function of the Lag but also as a function of the average inital

H. B. Nie, C. K. Ong, J. P. Wang, Z. W. Li

FeTaN/TaN/FeTaN sandwich films, FeTaN/TaN and TaN/FeTaN bilayers were synthesized by using RF magnetron sputtering. The magnetic properties, crystalline structures, microstructures and surface morphologies of the as-deposited samples were characterized using angle-resolved M-H loop tracer, VSM, XRD, TEM, AES and AFM. An evolution of the in-plane anisotropy w

M. Q. Weng, M. W. Wu

By constructing and numerically solving the kinetic Bloch equations we perform a many-body study of the spin dephasing due to the D&#39;yakonov-Perel&#39; effect in $n$-typed GaAs (100) quantum wells for high temperatures. In our study, we include the spin-conserving scattering such as the electron-phonon, the electron-nonmagnetic impurity as well as the ele

A A Ovchinnikov, M Ya Ovchinnikova

Influence of two type of spin structures on the form of the Fermi surface (FS) and a photoemission intensity map is studied for t-t&#39;-U Hubbard model. Mean field calculations are done for the stripe phase and for the spiral spin structure. It is shown, that unlike a case of electron doping, the hole-doped models are unstable with respect to formation of s

M. Drndic, R. Markov, M. V. Jarosz, M. G. Bawendi

A novel method to image charge is used to measure the diffusion coefficient of electrons in films of CdSe nanocrystals at room temperature. This method makes possible the study of charge transport in films exhibiting high resistances or very small diffusion coefficients.

A. I. Leonov, V. S. Volkov

The paper investigates the general case of incompressible non-classical elasticity with small deformations and rotations. It is shown that the internal spin rotations are important only when a specific Born term is presented in the free energy. The thermodynamic stability conditions and existence of soft deformational modes are analysed for free energy with

Y. Yasukawa, M. Karppinen, J. Linden, T. S. Chan

In the Fe-Mo based B-site ordered double-perovskite, A2FeMoO6.0, with iron in the mixed-valence II/III state, the valence value of Fe is not precisely fixed at 2.5 but may be fine-tuned by means of applying chemical pressure at the A-cation site. This is shown through a systematic 57Fe Mossbauer spectroscopy study using a series of A2FeMoO6.0 [A = (Ba,Sr) or

G. Fratesi, G. P. Brivio, Patrick Rinke, R. W. Godby

The electronic properties of a semi-infinite metal surface without a bulk gap are studied by a formalism able to account for the continuous spectrum of the system. The density of states at the surface is calculated within the $GW$ approximation of many-body perturbation theory. We demonstrate the presence of an unoccupied surface resonance peaked at the posi

Mark S. Handcock, James Holland Jones, Martina Morris

Recent work has focused attention on statistical inference for the population distribution of the number of sexual partners based on survey data. The characteristics of these distributions are of interest as components of mathematical models for the transmission dynamics of sexually-transmitted diseases (STDs). Such information can be used both to calibrate

B. Basu

We propose a mechanism of high temperature superconductivity from the viewpoint of chirality and Berry phase. It is observed that spin pairing and charge pairing is caused by a gauge force generated by magnetic flux quanta attached to them. From the renormalization group equation involving the Berry phase factor $μ$ it is found that there are two crossovers

Shin-Tza Wu, Sungkit Yip

We show that the recent Comment by Liu and Wilczek (cond-mat/0304632) on our work (PRA 67, 053603) is incorrect.

Ikuo S. Sogami

A generating functional which results in the Poisson-Boltzmann equation and boundary conditions for an average electric potential of a macroionic suspension through an extremal condition is constructed in a mean field theory. The extremum of the generating functional turns out to be identical with the Helmholtz free energy of the system which has an integral

Kan Chen, Bing-Hong Wang, Baosheng Yuan

We discover the mechanism for the transition from self-segregation (into opposing groups) to clustering (towards cautious behaviors) in the evolutionary minority game (EMG). The mechanism is illustrated with a statistical mechanics analysis of a simplified EMG involving three groups of agents: two groups of opposing agents and one group of cautious agents. T

A. Rosencwaig

The (Cu)13-BEC model of high-temperature superconductivity was previously shown to account for many of the principal thermodynamic and electronic properties of the superconducting cuprates. Here I show that this model is also able to account for many of the key characteristics of the coupled CDW and SDW orders in these compounds. These include the general co

F. Leyvraz

The scaling theory of irreversible aggregation is discussed in some detail. First, we review the general theory in the simplest case of binary reactions. We then extend consideration to ternary reactions, multispecies aggregation, inhomogeneous situations with arbitrary size dependent diffusion constants as well as arbitrary production terms. A precise formu

I. V. Solovyev

This a review article, which presents a general framework for the analysis of interatomic magnetic interactions in the spin-density-functional theory, which is based on the magnetic force theorem, make a link with the models for transition-metal oxides, and gives several examples of how this strategy can be used for the analysis of magnetic properties of col

Kazuhiko Seki, Mariusz Wojcik, M. Tachiya

A fractional reaction-diffusion equation is derived from a continuous time random walk model when the transport is dispersive. The exit from the encounter distance, which is described by the algebraic waiting time distribution of jump motion, interferes with the reaction at the encounter distance. Therefore, the reaction term has a memory effect. The derived

R. Micnas

We outline a microscopic approach to the superconducting fluctuations and pairing correlations in the attractive Hubbard model above Tc, using the functional integral method. A crossover from BCS superconductivity to Bose condensation of preformed pairs is studied by constructing the appropriate Ginzburg-Landau functionals. The differences between the lattic

Nader Haghighipour, Alan P. Boss

We study the motions of small solids, ranging from micron-sized dust grains to meter-sized objects, in the vicinity of local pressure enhancements of a gaseous nebula. Integrating numerically, we show that as a result of the combined effect of gas drag and pressure gradients, solids tend to accumulate at the locations where the pressure of the gas maximizes.

K. Kosack

We present the results of 16 hours of ongoing observations of the galactic center region (including Sagittarius A*) with the Whipple High Energy Gamma-Ray Telescope. We apply a data analysis method optimized for large zenith angle observations on an independent Crab Nebula data set. We discuss possible systematic problems associated with observations of exte

E. L. Wright

The theoretical basis for the prediction of anisotropies in the cosmic microwave background is very well developed. Very low amplitude density and temperature perturbations produce small gravitational effects, leading to an anisotropy that is a combination of temperature fluctuations at the surface of last scattering and gravitational redshifts both at last

Angelica de Oliveira-Costa, Max Tegmark, Christopher O&#39;Dell, Brian Keating

Most of the useful information about inflationary gravitational waves and reionization is on large angular scales where Galactic foreground contamination is the worst, so a key challenge is to model, quantify and remove polarized foregrounds. We use the Leiden radio surveys to quantify the polarized synchrotron radiation at large angular scales, which is lik

Kartik Sheth, Michael W. Regan, Nick Scoville, Linda Strubbe

Previous optical studies found an unexpected deficit of bars at z > 0.7. To investigate the effects of bandshifting, we have studied the fraction of barred spirals in the NICMOS Deep Field North. At z > 0.7 we find at least four barred spirals, doubling the number previously detected. The number of barred galaxies is small because these (and previous) data l

Lloyd Knox

I comment on the challenges and opportunities presented by an extended period of reionization.

G. Walker

An all-sky survey performed with the Tibet Air Shower Array (Tibet AS) has found a number of potential point sources of TeV gamma rays. If they are steady sources, the implied Tibet AS fluxes should be visible with strong significance to the Whipple 10-m gamma-ray telescope (E > 400 GeV) with only a short (5 hour) exposure. We have observed four candidate di