December 2004 arXiv papers — page 5

K. Bandyopadhyay, A. K. Bhattacharya, Parthapratim Biswas, D. A. Drabold

We present a technique for entropy optimization to calculate a distribution from its moments. The technique is based upon maximizing a discretized form of the Shannon entropy functional by mapping the problem onto a dual space where an optimal solution can be constructed iteratively. We demonstrate the performance and stability of our algorithm with several

M. K. Crawford, R. L. Harlow, S. Deemyad, V. Tissen

We have determined the crystal structures and superconducting transition temperatures of La1.48Nd0.4Sr0.12CuO4 under nearly hydrostatic pressures in diamond anvil cells to 5.0 GPa and 19.0 GPa, respectively. Synchrotron x-ray powder diffraction measurements were used to establish the pressure-temperature structural phase diagram. Under pressure the supercond

M. Bartenstein, A. Altmeyer, S. Riedl, S. Jochim

We present an overview of our recent measurements on the crossover from a Bose-Einstein condensate of molecules to a Bardeen-Cooper-Schrieffer superfluid. The experiments are performed on a two-component spin-mixture of $^6$Li atoms, where a Fesh\-bach resonance serves as the experimental key to tune the s-wave scattering length and thus to explore the vario

L. Wu, Y. Zhu, S. Park, S. Shapiro

Using transmission electron microscopy (TEM) we studied CaCu3Ti4O12, an intriguing material that exhibits a huge dielectric response, up to kilohertz frequencies, over a wide range of temperature. Neither in single crystals, nor in polycrystalline samples, including sintered bulk- and thin-films, did we observe the twin domains suggested in the literature. N

So Takei, Yong Baek Kim, Aditi Mitra

We study the effects of electron-phonon interactions on the transport properties of a molecular quantum dot coupled to two Luttinger-liquid leads. In particular, we investigate the effects on the steady state current and DC noise characteristics. We consider both equilibrated and unequilibrated on-dot phonons. The density matrix formalism is applied in the h

S. Faniel, E. Tutuc, E. P. De Poortere, C. Gustin

We report thermopower measurements of interacting GaAs bilayer hole systems. When the carrier densities in the two layers are equal, these systems exhibit a reentrant insulating phase near the quantum Hall state at total filling factor $ν=1$. Our data show that as the temperature is decreased, the thermopower diverges in the insulating phase. This behavior i

Jan Kolacek, Tzong-Jer Yang

It is widely believed that temperature gradient does not induce electric field in the superconductor and consequently that thermoelectric effects do not exist, or are negligible in these materials. This statement is correct only as far as effective electric field or gradient of the electrochemical potential is concerned. In normal metals temperature gradient

Francesc Comellas, Silvia Gago

Using a simple deterministic model for the Internet graph we show that the eigenvalue power law distribution for its adjacency matrix is a direct consequence of the degree distribution and that the graph must contain many star subgraphs.

Yuriy I. Kuzmin

Depinning of vortices in percolative superconductor containing fractal clusters of a normal phase is considered. Transition of the superconductor into a resistive state corresponds to the percolation transition from a pinned vortex state to a resistive state when the vortices are free to move. The motion of the magnetic flux transferred by these vortices giv

S. -T. Chui, V. N. Ryzhov, E. E. Tareyeva

An effective Hamiltonian for the Bose system in the mixture of ultracold atomic clouds of bosons and fermions is obtained by integrating out the Fermi degrees of freedom. An instability of the Bose system is found in the case of attractive interaction between components in good agreement with the experiment on the bosonic $^{87}$Rb and fermionic $^{40}$K mix

V. N. Ryzhov, E. E. Tareyeva

The transitions in disordered substances are discussed briefly: liquid--liquid phase transitions, liquid--glass transition and the transformations of one amorphous form to another amorphous form of the same substances. A description of these transitions in terms of many--particle conditional distribution functions is proposed. The concept of a hidden long ra

J. Wong-ekkabut, W. Triampo, I-Ming Tang, D. Triampo

We have investigated the time evolution of the vacancy-mediated disordering process in binary alloys at finite temperatures. Qualitatively, we monitor the changes in the configurations by taking sequences of snapshots for various temperatures and comparing their morphologies. Quantitatively, we carry out Monte Carlo simulations to determine the time-dependen

Alex Levchenko

The effect of suppression of static magnetization of an anisotropic hard superconductor by alternating magnetic field is analyzed theoretically. The magnetic moment suppression dynamics is described with respect to the magnetization loop of the superconductor. It is found that in some cases the magnetic moment varies nonmonotonically with the growth in ampli

Tetsufumi Tanamoto, Shinobu Fujita

We analyze the robustness of decoherence-free (DF) subspace and subsystem in charge qubits, when difference from the collective decoherence measurement condition is large in the long time period, which is applicable for solid-state qubits using as a quantum memory. We solve master equations of up to four charge qubits and a detector as a quantum point contac

Atsunari Katsuki, Macoto Kikuchi, Noritaka Endo

We observed time evolution of dune fields in a water tank experiment and simulated it by using a simple model without taking complex fluid dynamics into account. The initial sand bed changed its form into transverse ripples, that is, dunes with straight crest lines perpendicular to the flow direction. Then the crescentic shaped dunes called barchans emerged

Daniel L. Blair, Arshad Kudrolli

We measure the geometry of a crumpled sheet of paper with laser-aided topography and discuss its statistical properties. The curvature of an elasto-plastic fold scales linearly with applied force. The curvature distribution follows an exponential form with regions of high curvature localized along ridges. The measured ridge length distribution is consistent

Yongle Yu

In an ultracold mixture of two different Fermi species of atoms, Cooper pairs can be formed between two different atoms. The masses of one atom and its partner in this kind of Cooper pairs may differ by order of magnitude. In this system, each species of atoms are in the same atomic spin state and two species have the same atomic densities. The pairing gap d

Yuriy I. Kuzmin, Mladen Prester

The influence of fractal clusters of a normal phase on distinctive features of current-voltage characteristic of percolative type-II superconductors is considered. The results of high-resolution measurements of the differential resistance of BPSCCO/Ag composites are discussed in the context of magnetic flux dynamics. The region of initial dissipation is obse

E. V. Bugaev, K. V. Konishchev

We obtain the constraints on the diffuse neutrino background from primordial black hole evaporations using the recent data of KamLAND experiment setting an upper limit on the antineutrino flux from the Sun.

Esteban Roulet

A general overview of neutrino physics is given, starting with a historical account of the development of our understanding of neutrinos and how they helped to unravel the structure of the Standard Model. We discuss why it is so important to establish if neutrinos are massive and the indications in favor of non-zero neutrino masses are discussed, including t

T. Ak, A. Retter, A. Liu, H. H. Esenoglu

We present the results obtained from unfiltered photometric CCD observations of the newly discovered cataclysmic variable SDSS J040714.78-064425.1 made during 7 nights in November 2003. We establish the dwarf nova nature of the object as it was in outburst during our observations. We also confirm the presence of deep eclipses with a period of 0.17017d+/-0.00

Karen M. Leighly

Significant (marginal) detections of periodic signals have been recently reported in 3 (4) Active Galactic Nuclei. Three of the detections were obtained from long EUVE light curves of moderate-luminosity Seyfert galaxies; the fourth was discovered in Chandra data from the low-luminosity Seyfert 1 galaxy NGC 4395. When compared with Cyg X-1, I find that the p

L. R. Yungelson

A review of the basic principles of the population synthesis for binary stars is presented. We discuss the break-up of low and intermediate mass close binaries over different evolutionary scenarios and, as an example, briefly consider results of the population synthesis for SN Ia.

A. Rodriguez-Ardila, M. Contini, S. M. Viegas

We present the first spectroscopic observations in the interval 0.8-4.0 microns, complemented with HST/UV and optical spectroscopy, of the narrow line Seyfert 1 galaxy Mrk766. The NIR spectrum is characterized by permitted lines of HI, HeI, HeII and FeII, and forbidden lines of [SII], [SIII] and [FeII] among others. High ionized species such as [SiIX], [SiX]

Hu Zhan, Daniel Eisenstein

We analyse the covariance of the one-dimensional mass power spectrum along lines of sight. The covariance reveals the correlation between different modes of fluctuations in the cosmic density field and gives the sample variance error for measurements of the mass power spectrum. For Gaussian random fields, the covariance matrix is diagonal. As expected, the v

A. M. Ghezelbash, R. B. Mann

We consider Kerr-de Sitter spacetimes and evaluate their mass, angular momentum and entropy according to the boundary counterterm prescription. We provide a physicall interpretation for angular velocity and angular momentum at future/past infinity. We show that the entropy of the four-dimensional Kerr-de Sitter spacetimes is less than of pure de Sitter space

Georgios Kofinas

We study braneworlds in six-dimensional Einstein-Gauss-Bonnet gravity. The Gauss-Bonnet term is crucial for the equations to be well-posed in six dimensions when non-trivial matter on the brane is included (the also involved induced gravity term is not significant for their structure), and the matching conditions of the braneworld are known. We show that the

Th. Grammenos

We use Moeller's energy-momentum complex in order to explicitly evaluate the energy and momentum density distributions associated with the three-dimensional magnetic solution to the Einstein-Maxwell equations. The magnetic spacetime under consideration is a one-parametric solution describing the distribution of a radial magnetic field in a three-dimensio

Fei-Fan Lee, Guey-Lin Lin

We present a semi-analytic calculation on the atmospheric tau neutrino flux in the GeV to TeV energy range. The atmospheric $ν_τ$ flux is calculated for the entire zenith angle range. This flux is contributed by the oscillations of muon neutrinos coming from the two-body $π, K$ decays and the three-body $μ^{\pm}$ decays, and the intrinsic tau neutrino flux s

A. Rezaei-Aghdam, M. Hemmati, A. R. Rastkar

Classical r-matrices of the three-dimensional real Lie bialgebras are obtained. In this way all three-dimensional real coboundary Lie bialgebras and their types (triangular, quasitriangular or factorizable) are classified. Then, by using the Sklyanin bracket, the Poisson structures on the related Poisson-Lie groups are obtained.

Ting Xiao, Yunbo Zeng

The mKP equation with self-consistent sources (mKPESCS) is treated in the framework of the constrained mKP hierarchy. We introduce a new constrained mKP hierarchy which may be viewed as the stationary hierarchy of the mKP hierarchy with self-consistent sources. This offers a natural way to obtain the Lax representation for the mKPESCS. Based on the conjugate

H. Abuki, M. Kitazawa, T. Kunihiro

We investigate the effects of the dynamical formation of the chiral condensates on color superconducting phases under the electric and color neutrality constraints at vanishing temperature. We shall show that the phase appearing next to the color-flavor-locked (CFL) phase down in density depends on the strength of the diquark coupling. In particular, the gap

S. M. Zabihinpoor, A. Dariush, N. Riazi

Photometric observations of GO Cyg were performed during the July-October 2002, in B and V bands of Johnson system. Based on Wilson&#39;s model, the light curve analysis were carried out to find the photometric elements of the system. The O-C diagram which is based on new observed times of minima suggests a negative rate of period variation (dP/dt<0) for the

Daekyoung Kang, Jong-Wan Lee, Jungil Lee, Taewon Kim

Measurements by the Belle Collaboration of the cross section for inclusive J/psi production in e^+e^- annihilation have been a serious challenge to current heavy-quarkonium theory. Especially, the measured cross sections for exclusive J/psi+eta_c and inclusive J/psi+cc-bar+X differ from nonrelativistic QCD predictions by an order of magnitude. In order to ch

Thomas Durt, Jaromir Fiurasek, Nicolas J. Cerf

The possibility of cloning a d-dimensional quantum system without an ancilla is explored, extending on the economical phase-covariant cloning machine found in [Phys. Rev. A {\bf 60}, 2764 (1999)] for qubits. We prove the impossibility of constructing an economical version of the optimal universal cloning machine in any dimension. We also show, using an ansat

Xiao-Shu Liu, Wu Re-bing, Yang Liu, Jing Zhang

In this paper, we study the suppression of adiabatic decoherence in a three-level atom with $Λ$ configuration using bang-bang control technique. We have given the decoupling bang-bang operation group, and programmed a sequence of periodic radio frequency twinborn pulses to realize the control process. Moreover, we have studied the process with non-ideal situ

Giulia Battilotti, Paola Zizzi

We investigate the internal logic of a quantum computer with two qubits, in the two particular cases of non-entanglement (separable states) and maximal entanglement (Bell&#39;s states). To this aim, we consider an internal (reversible) measurement which preserves the probabilities by mirroring the states. We then obtain logical judgements for both cases of s

Eyal Buks

We consider an all in-fiber optical modulator based on a ring resonator configuration. The case of adiabatic to nonadiabatic transition is considered, where the geometrical (Berry) phase acquired in a round trip along the ring changes abruptly by pi. Degradation of the responsivity of the modulator due to finite linewidth of the optical input is discussed. W

Yuri Ozhigov

Algorithmic approach is based on the assumption that any quantum evolution of many particle system can be simulated on a classical computer with the polynomial time and memory cost. Algorithms play the central role here but not the analysis, and a simulation gives a &#34;film&#34; which visualizes many particle quantum dynamics and is demonstrated to a user

Mark Ya. Azbel&#39;

Exact law of mortality dynamics in changing populations and environment is derived. The law is universal for all species, from single cell yeast to humans. It includes no characteristics of animal- environment interactions (metabolism etc) which are a must for life. Such law is unique for live systems with their homeostatic self-adjustment to environment. It

Eli Eisenberg, Sergey Nemzer, Yaron Kinar, Rotem Sorek

A-To-I RNA editing is common to all eukaryotes, associated with various neurological functions. Recently, A-to-I editing was found to occur abundantly in the human transcriptome. Here we show that the frequency of A-to-I editing in humans is at least an order of magnitude higher as that of mouse, rat, chicken or fly. The extraordinary frequency of RNA editin

A. Badertscher, M. Laffranchi, A. Rubbia

A novel liquid argon (LAr) purity monitor was developed with a sensitivity to electronegative impurities of the order of ppb (O$_2$ equivalent). Such a high purity is e.g. needed in a LAr drift chamber. The principle is to measure the lifetime of quasifree electrons in LAr, since this is the important parameter for the operation of a drift chamber. Free elec

A. A. Isayev, S. I. Bastrukov, J. Yang

Using equations, governing np pairing correlations in S=1, T=0 pairing channel (PRC 63 (2001) 021304(R)), it is shown that at low densities equations for the energy gap in the spectrum of quasiparticles and chemical potentials of protons and neutrons allow solutions with negative chemical potential. This corresponds to appearance of Bose--Einstein condensate

V. A. Abramovsky, N. V. Prikhod&#39;ko

In this paper we consider Cronin momentum behaviour for $p+A$, $d+A$ and $A+A$ collisions in saturation model. Our analysis shows that Cronin momentum behavior at different rapidities and energies, can be related with scaling law using simple dimensional consideration. Using exact numerical solution of Balitsky-Kovchegov equation we show that although this d

David Damanik, Christian Remling

Consider the Schrödinger operators $H_{\pm}=-d^2/dx^2\pm V(x)$. We present a method for estimating the potential in terms of the negative eigenvalues of these operators. Among the applications are inverse Lieb-Thirring inequalities and several sharp results concerning the spectral properties of $H_{\pm}$.

Steven Dale Cutkosky

In this paper we prove strong toroidalization of birational morphisms of 3-folds. Suppose that f:X\to Y is a birational morphism of nonsingular complete 3-folds, and D_Y, D_X are simple normal crossings divisors on Y and X such that f^{-1}(D_Y)=D_X and D_X contains the singular locus of the morphism f. We prove that there exist morphisms Φ:X_1\to X and Ψ:Y_1

Anna Karczewska

We study stochastic convolutions providing by fundamental solutions of a class of integrodifferential equations which interpolate the heat and the wave equations. We give sufficient condition for the existence of function--valued convolutions in terms of the covariance kernel of a noise given by spatially homogeneous Wiener process.

Jinho Baik, Toufic M. Suidan

We prove a GUE central limit theorem for random variables with finite fourth moment. We apply this theorem to prove that the directed first and last passage percolation problems in thin rectangles exhibit universal fluctuations given by the Tracy-Widom law.

Zhi-Wei Sun

Let A={a_s(mod n_s)}_{s=0}^k be a system of residue classes. With the help of cyclotomic fields we obtain a theorem which unifies several previously known results concerning system A. In particular, we show that if every integer lies in more than m=[sum_{s=1}^k 1/n_s] members of A, then for any a=0,1,2,... there are at least binom{m}{[a/n_0]} subsets I of {1

Dusa McDuff

This paper studies groups of symplectomorphisms of ruled surfaces for symplectic forms with varying cohomology class. This class is characterized by the ratio R of the size of the base to that of the fiber. By considering appropriate spaces of almost complex structures, we investigate how the topological type of these groups changes as R increases. If the ba

Yaron Oz

We construct topological B-model descriptions of \hat{c}=1 strings, and corresponding Dijkgraaf-Vafa type matrix models and quiver gauge theories.

Muneto Nitta

We present new non-Ricci-flat Kahler metrics with U(N) and O(N) isometries as target manifolds of superconformally invariant sigma models with an anomalous dimension. They are so-called Ricci solitons, special solutions to a Ricci-flow equation. These metrics explicitly contain the anomalous dimension and reduce to Ricci-flat Kahler metrics on the canonical

Holger Mueller

We consider tests of Lorentz invariance for the photon and fermion sector that use vacuum and matter-filled cavities. Assumptions on the wave-function of the electrons in crystals are eliminated from the underlying theory and accurate sensitivity coefficients (including some exceptionally large ones) are calculated for various materials. We derive the Lorent

T. M. Aliev, V. Bashiry, M. Savci

Polarized forward-backward asymmetries in the (B_s -> l^+ l^- gamma) decay are calculated using the most general, model independent form of the effective Hamiltonian, including all possible forms of interactions. The dependencies of the asymmetries on new Wilson coefficients are investigated. The detectability of the asymmetries at LHC is discussed.

N. Grønbech-Jensen, M. G. Castellano, F. Chiarello, M. Cirillo

We investigate, by experiments and numerical simulations, thermal activation processes of Josephson tunnel junctions in the presence of microwave radiation. When the applied signal resonates with the Josephson plasma frequency oscillations, the switching current may become multi-valued temperature ranges both below and above the the classical to quantum cros

V. I. Zubov, C. G. Rodrigues, I. V. Zubov

We study thermodynamic properties of the high-temperature modification of fullerites on the basis of the Girifalco intermolecular potential. In the present work, using the Lindemann&#39;s melting criterion we estimate a possible melting curve Tm(P) of C60 fullerite. To take into account the lattice anharmonicity that has strong effect at T >700 K, we use the

A. D. Kiselev, T. J. Sluckin

We consider helical configurations of a cholesteric liquid crystal (CLC) sandwiched between two substrates with homogeneous director orientation favored at both confining plates. We study the CLC twist wavenumber $q$ characterizing the helical structures in relation to the free twisting number $q_0$ which determines the equilibrium value of CLC pitch, $P_0=2

Kyungjin Ahn, Eiichiro Komatsu

Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft gamma-ray background of the redshifted 511 keV photons from cosmological halos. Annihilation of dark matter particles into electron-positron pairs makes a substantial contribution to the gamma-ray background. Mass of such dark matter partic

Lawrence Rudnick

Observations of magnetic fields on scales up to several Mpc are important for understanding cluster and large-scale structure evolution. Our current census of such structures is heavily biased -- towards fields of several microG, towards fields in deep potential wells, and towards high inferred field strengths in cooling flow and other clusters from improper

Emiliano Sefusatti, Roman Scoccimarro

We show that current surveys have at least as much signal to noise in higher-order statistics as in the power spectrum at weakly nonlinear scales. We discuss how one can use this information to determine the mean of the galaxy halo occupation distribution (HOD) using only large-scale information, through galaxy bias parameters determined from the galaxy bisp

Stephen L. Olsen

I report recent results on hidden charm spectroscopy from Belle. These include: observation of a near-threshold enhancement in the omega-J/psi invariant mass distribution for exclusive B-->K omega J/psi decays; evidence for the decay X(3872)-->pi+pi-pi0 J/psi, where the pi+pi-pi0 invariant mass distribution has a strong peak between 750 MeV and the kinematic

A. A. Andrianov, D. Espriu, A. Prats

The QCD hadronic string is supplemented with the reparameterization-invariant boundary interaction to background chiral fields associated with pions in a way compatible with the conformal symmetry. It allows the full reconstruction of the P-even part of the Chiral Lagrangian in a good agreement with the phenomenology of P-even meson interactions. The modific

Zhengyan Gu, Hongbo Cheng

The equation of cosmic string loops in Kerr-de Sitter spacetimes is derived. Having solved the equation numerically, we find that the loops can expand and exist except for too small ones.

Mladen Pavicic

Algorithms for finding arbitrary sets of Kochen-Specker (KS) qunits (n-level systems) as well as all the remaining vectors in a space of an arbitrary dimension are presented. The algorithms are based on linear MMP diagrams which generate orthogonalities of KS qunits, on an algebraic definition of states on the diagrams, and on nonlinear equations correspondi

A. Loinger

In general relativity (GR) no observer is physically privileged. As a strict consequence, it can be shown that the physical generation of gravitational waves (GW&#39;s) is quite impossible.

H. Yamamoto, E. Makita, Y. Oki, M. Otani

The normality dependence and the kinetics of flow behavior in the rice starch dispersion under strong alkali conditions were studied. Non-Newtonian flow (power-law) quantities n and μ(σ=μ(\dotε)^n; σ: shear stress, \dotε: shear rate) of the samples stored (gelatinized) at 20^{\circ}C for 10min after the addition of NaOH solution with the normality 0.090 - 0.

D. Holcman, Z. Schuss

Traditional chemical kinetics may be inappropriate to describe chemical reactions in micro-domains involving only a small number of substrate and reactant molecules. Starting with the stochastic dynamics of the molecules, we derive a master-diffusion equation for the joint probability density of a mobile reactant and the number of bound substrate in a confin

David Holcman, Ivan Kupka

On a compact Riemannian manifold (V_{m},g), we consider the second order positive operator L_ε = εΔ_{g} +(b,\nabla) +c, where -Δ_{g} is the Laplace-Beltrami operator and b is a Morse-Smale (MS) field, εa small parameter. We study the measures which are the limits of the normalized first eigenfunctions of L_ε as εgoes to the zero. In the case of a general MS

Alexander Gnedin, Jim Pitman

For two collections of nonnegative and suitably normalised weights $\W=(\W_j)$ and $\V=(\V_{n,k})$, a probability distribution on the set of partitions of the set $\{1,...,n\}$ is defined by assigning to a generic partition $\{A_j, j\leq k\}$ the probability $\V_{n,k} \W_{|A_1|}... \W_{|A_k|}$, where $|A_j|$ is the number of elements of $A_j$. We impose cons

Farida Iddir, Lahouari Semlala

QCD theory allows the existence of states which cannot be built by the naive quark model; both theoretical arguments and experimental data confirm the hypothesis that gluons may have freedom degrees at the constituent level, and should be confined. In this work, we use a phenomenological potential motivated by QCD (with some relativistic corrections) to dete

Katsumi Itoh, Mitsuhiro Kato, Michika Murata, Hideyuki Sawanaka

We present a new formulation of the staggered fermion on the D-dimensional lattice based on the SO(2D) Clifford algebra, which is naturally present in the action. The action of the massless staggered fermion is invariant under the discrete rotation and the SO(2D) chiral and other discrete transformations. From transformation properties of the fermion, we fin

A. Drutskoy

Recent measurements involving the newly discovered D_sJ particles are reported. The results of D_sJ production and decay branching fraction measurements are shown. Possible spin-parity and quark content assignments of D_sJ mesons are discussed. The results are based on a large data sample recorded by the Belle detector at the KEKB e^+ e^- collider.

Alexander K. Motovilov, Vladimir B. Belyaev

We consider finite linear or cyclic crystalline structures with molecular cells having narrow pre-threshold nuclear resonance. We prove that if the real part of such a nuclear resonance lies within the energy band (the convex hull of the energy levels) of the crystalline structure arising of a separated molecular level, then there exist molecular crystalline

A. O. Sboychakov, A. L. Rakhmanov, K. I. Kugel, I. González

The thermal behavior of a one-dimensional antiferromagnetic chain doped by donor impurities was analyzed. The ground state of such a chain corresponds to the formation of a set of ferromagnetically correlated regions localized near impurities (bound magnetic polarons). At finite temperatures, the magnetic structure of the chain was calculated simultaneously

T. Yamasaki, S. Yamada

In order to infer the effects of rotation on the revival of a stalled shock in supernova explosions, we investigated steady accretion flows with a standing shock. We first obtained a series of solutions for equations describing non-rotating spherically symmetric flows and confirmed the results of preceding papers that, for a given mass accretion rate, there

Zong-Kuan Guo, Rong-Gen Cai, Yuan-Zhong Zhang

We investigate the cosmological evolution of an interacting phantom energy model in which the phantom field has interaction with the dark matter. We discuss the existence and stability of scaling solutions for two types of specific interactions. One is motivated by the conformal transformation in string theory and the other is motivated by analogy with dissi

A. M. Bratkovsky, A. Cano, A. P. Levanyuk

We show that subwavelength imaging by negative index materials (NIM), related to their &#34;soft&#34; electromagnetic response, is very (and non trivially) sensitive to the surface properties. A minute deviation of dielectric permittivity epsilon or magnetic permeability mu from the ideal values epsilon = mu = -1 in thin surface layer(s) results in drastic r

Alexander Barg

A new lower bound on the error probability of maximum likelihood decoding of a binary code on a binary symmetric channel was proved in Barg and McGregor (2004, cs.IT/0407011). It was observed in that paper that this bound leads to a new region of code rates in which the random coding exponent is asymptotically tight, giving a new region in which the reliabil

S. E. Parkhomenko

We represent free-field construction of boundary states in Gepner models basing on free-field realization of N=2 superconformal minimal models. Using this construction we consider the open string spectrum between the boundary states and show that it can be described in terms of Malikov, Schechtman, Vaintrob chiral de Rham complex of the Landau- Ginzburg orbi

Daniel Groves

We begin the investigation of Gamma-limit groups, where Gamma is a torsion-free group which is hyperbolic relative to a collection of free abelian subgroups. Using the results of Drutu and Sapir, we adapt the results from math.GR/0404440 to this context. Specifically, given a finitely generated group G, and a sequence of pairwise non-conjugate homomorphisms

Jorge Alfaro

The most important problem of fundamental Physics is the quantization of the gravitational field. A main difficulty is the lack of available experimental tests that discriminate among the theories proposed to quantize gravity. Recently, Lorentz invariance violation by Quantum Gravity(QG) have been the source of a growing interest. However, the predictions de

N. Matagne, Fl. Stancu

We use the $1/N_c$ expansion of QCD to analyze the spectrum of positive parity resonances with strangeness $S = 0, -1, -2$ and -3 in the 2--3 GeV mass region, supposed to belong to the $[\textbf{56},4^+]$ multiplet. The mass operator is similar to that of $[\textbf{56},2^+]$, previously studied in the literature. The analysis of the latter is revisited. In t

Amit Giveon, Amit Sever

String theory on 2-d charged black holes corresponding to (SL(2)xU(1)_L)/U(1) exact asymmetric quotient CFTs are investigated. These backgrounds can be embedded, in particular, in a two dimensional heterotic string. In the extremal case, the quotient CFT description captures the near horizon physics, and is equivalent to strings in AdS_2 with a gauge field.

R. Mizuk

We report the observation of an isotriplet of excited charmed baryons, decaying into Lambda_c+ pi-, Lambda_c+ pi0 and Lambda_c+ pi+. We measure the mass differences M(Lambda_c+ pi)-M(Lambda_c+) and widths to be 515.4 +3.2-3.1 +2.1-6.0 MeV/c^2, 61 +18-13 +22-13 MeV for the neutral state; 505.4 +5.8-4.6 +12.4-2.0 MeV/c^2, 62 +37-23 +52-38 MeV for the charged s

Rajesh R. Parwani

Information-theoretic arguments are used to obtain a link between the accurate linearity of Schrodinger&#39;s equation and Lorentz invariance: A possible violation of the latter at short distances would imply the appearance of nonlinear corrections to quantum theory. Nonlinear corrections can also appear in a Lorentz invariant theory in the form of higher de

Lara B. Anderson, James T. Wheeler

We write a gravity theory with Yang-Mills type action using the biconformal gauging of the conformal group. We show that the resulting biconformal Yang-Mills gravity theories describe 4-dim, scale-invariant general relativity in the case of slowly changing fields. In addition, we systematically extend arbitrary 4-dim Yang-Mills theories to biconformal space,

Petra E. Jonsson, Hajime Takayama

The field-cooled magnetization (FCM) processes of Ising spin glasses under relatively small fields are investigated by experiment on Fe_{0.55}Mn_{0.45}TiO_3 and by numerical simulation on the three-dimensional Edwards-Anderson model. Both results are explained in a unified manner by means of the droplet picture. In particular, the cusp-like behavior of the F

Varghese Mathai, Danny Stevenson

A central result here is the computation of the entire cyclic homology of canonical smooth subalgebras of stable continuous trace C*-algebras having smooth manifolds M as their spectrum. More precisely, the entire cyclic homology is shown to be canonically isomorphic to the continuous periodic cyclic homology for these algebras. By an earlier result of the a

Xiao-Gang He, Xue-Qian Li, Bruce H. J. McKellar, Yue Zhang

We study the Berry phase in neutrino oscillations for both Dirac and Majorana neutrinos. In order to have a Berry phase, the neutrino oscillations must occur in a varying medium, the neutrino-background interactions must depend on at least two independent densities, and also there must be CP violation if the neutrino interactions with matter are mediated onl

Takeshi Fukuyama, Tatsuru Kikuchi

The connection between the axion and right-handed neutrinos is explored in the framework of the minimal SUSY SO(10) model. The former is related to the Peccei-Quinn (PQ) solution to the strong CP problem and the latter is to the light Majorana neutrinos through the see-saw mechanism. In this model, a relative phase between $({\bf 10,1,3}) (\equiv {\bf \barΔ}

H. Katagiri, R. Enomoto, L. T. Ksenofontov, M. Mori

We have detected gamma-ray emission at the 6sigma level at energies greater than 500GeV from the supernova remnant RX J0852.0-4622 (G266.2-1.2) using the CANGAROO-II Imaging Atmospheric Cherenkov Telescope (IACT). The flux was 0.12 times of that of Crab at 1TeV. The signal centroid is consistent with the peak of the X-ray emission in the north-west rim of th

D. E. Miller, J. R. Anglin, J. R. Abo-Shaeer, K. Xu

The coherence properties of a gas of bosonic atoms above the BEC transition temperature were studied. Bragg diffraction was used to create two spatially separated wave packets, which interfere during expansion. Given sufficient expansion time, high fringe contrast could be observed in a cloud of arbitrary temperature. Fringe visibility greater than 90% was o

Simon Saunders

Bohr&#39;s interpretation of quantum mechanics has been criticized as incoherent and opportunistic, and based on doubtful philosophical premises. If so Bohr&#39;s influence, in the pre-war period of 1927-1939, is the harder to explain, and the acceptance of his approach to quantum mechanics over de Broglie&#39;s had no reasonable foundation. But Bohr&#39;s i

Simon Saunders

Probabilities may be subjective or objective; we are concerned with both kinds of probability, and the relationship between them. The fundamental theory of objective probability is quantum mechanics: it is argued that neither Bohr&#39;s Copenhagen interpretation, nor the pilot-wave theory, nor stochastic state-reduction theories, give a satisfactory answer t

Ray-Kuang Lee, Yinchieh Lai, Yuri S. Kivshar

We study quantum correlations and quantum noise in the soliton collision described by a general two-soliton solution of the nonlinear Schrödinger equation, by using the back-propagation method. Our results include the standard case of a $sech$-shaped initial pulse analyzed earlier. We reveal that double-hump initial pulses can get more squeezed, and the sque

L. Pal

In 2001 Astumian published a very simple game which can be described by a Markov chain with absorbing initial and final states. In August 2004 Piotrowski and Sladowski asserted that Astumian&#39;s analysis was flawed. However, as was shown by Astumian, this statement was wrong. In this comment the properties of Markov chains corresponding to games that are m

A. P. Saiko

The paper examines superradiance in impurity crystals in the field of a coherent phonon wave excited by two ultrashort laser pulses via Raman scattering processes at the moment of preparation of the initial state of an ensemble of emitters. It is shown that by varying the power of the excitation pulses and their mutual direction of propagation, one can contr

V. M. Biryukov, A. G. Afonin, V. T. Baranov, S. Baricordi

A series of Silicon crystal undulator samples were produced based on the approach presented in PRL 90 (2003) 034801, with the periods of undulation from 0.1 mm to 1 mm, and the number of periods on the order of 10. The samples were characterized by X-rays, revealing the sine-like shape of the crystal lattice in the bulk. Next step in the characterization has

T. Mart, C. Bennhold

Kaon photoproduction on the nucleon has been investigated in the isobar (Feynman) and Regge frameworks. Two possible combinations of the theories are discussed. Results are compared with present experimental data.

T. Mart

Photoproduction of the Theta+ pentaquark on the proton is analyzed by using an isobar and a Regge models. The difference in the calculated total cross section is found to be more than two orders of magnitude for a hadronic form factor cut-off Lambda > 1 GeV. Comparable results would be obtained for 0.6 < Lambda < 0.8 GeV. We also calculate contribution of th