April 2005 arXiv papers — page 3

Ralph Blumenhagen, Gabriele Honecker, Timo Weigand

We consider the E8 x E8 heterotic string theory compactified on Calabi-Yau manifolds with bundles containing abelian factors in their structure group. Generic low energy consequences such as the generalised Green-Schwarz mechanism for the multiple anomalous abelian gauge groups are studied. We also compute the holomorphic gauge couplings and induced Fayet-Il

Sebastien Galtier, Annick Pouquet, Andre Mangeney

A heuristic model is given for anisotropic magnetohydrodynamics (MHD) turbulence in the presence of a uniform external magnetic field $B_0 {\bf {\hat e}_{\pa}}$. The model is valid for both moderate and strong $B_0$ and is able to describe both the strong and weak wave turbulence regimes as well as the transition between them. The main ingredient of the mode

Emily B. Dryden, Alexander Strohmaier

We show that for compact orientable hyperbolic orbisurfaces, the Laplace spectrum determines the length spectrum as well as the number of singular points of a given order. The converse also holds, giving a full generalization of Huber's theorem to the setting of compact orientable hyperbolic orbisurfaces.

José Ignacio Alvarez-Hamelin, Luca Dall'Asta, Alain Barrat, Alessandro Vespignani

We use the k-core decomposition to visualize large scale complex networks in two dimensions. This decomposition, based on a recursive pruning of the least connected vertices, allows to disentangle the hierarchical structure of networks by progressively focusing on their central cores. By using this strategy we develop a general visualization algorithm that c

L. Yungelson, A. Tutukov

By means of population synthesis we model the Galactic ensemble of helium stars. It is assumed that all helium stars are formed in binaries. Under this assumption, single helium stars are produced by the mergers of helium remnants of components of close binaries (mainly, by merging helium white dwarfs) and by disruption of binaries with helium components in

E. Athanassoula, F. -S. Ling, E. Nezri

We study the impact of the halo shape and geometry on the expected weakly interacting massive particle (WIMP) dark matter annihilation signal from the galactic center. As the halo profile in the innermost region is still poorly constrained, we consider different density behaviors like flat cores, cusps and spikes, as well as geometrical distortions. We show

Philippe Ruelle

Kramers-Wannier dualities in lattice models are intimately connected with symmetries. We show that they can be found directly and explicitly from the symmetry transformations of the boundary states in the underlying conformal field theory. Intriguingly the only models with a self-duality transformation turn out to be those with an auto-orbifold property.

Victor J. W. Guo, Jiang Zeng

For m>n\geq 0 and 1\leq d\leq m, it is shown that the q-Euler number E_{2m}(q) is congruent to q^{m-n}E_{2n}(q) mod (1+q^d) if and only if m\equiv n mod d. The q-Salié number S_{2n}(q) is shown to be divisible by (1+q^{2r+1})^{\left\lfloor \frac{n}{2r+1}\right\rfloor} for any r\geq 0. Furthermore, similar congruences for the generalized q-Euler numbers are a

Vladimir A. Zyuzin, A. Yu. Zyuzin

We consider the effect of electron-electron interactions on the current-in-plane (CIP) conductivity and exchange coupling energy of a disordered metallic magnetic multilayer. We analyze its dependence on the value of ferromagnetic splitting of conducting electrons and ferromagnetic layers relative magnetizations orientation. We show that contribution to the

Doron Cohen, Yoav Etzioni

The multimode conductance of a {\em closed} ring is found within the framework of a scattering approach. The expression can be regarded as a generalization of the Landauer formula. The treatment is essentially {\em classical} because we assume short coherence time. Our starting point is the Kubo formalism, but we also use a master equation approach for the d

Alastair Kay, Marie Ericsson

We examine the perfect cloning of non-local, orthogonal states with only local operations and classical communication. We provide a complete characterisation of the states that can be cloned under these restrictions, and their relation to distinguishability. We also consider the case of catalytic cloning, which we show provides no enhancement to the set of c

E. Megias, E. Ruiz Arriola, L. L. Salcedo

The low energy structure of the energy momentum tensor in several chiral quark models with SU(3) flavor symmetry is analyzed in the presence of external gravitational fields. To this end a derivative expansion in a curved four dimensional space time is considered. This allows us to compute the chiral coefficients $L_{11}$, $L_{12}$, and $L_{13}$, appearing w

H. Nagahiro, D. Jido, S. Hirenzaki

We present a theoretical study on formation rates of ηand ωmeson-nucleus systems induced by (γ,p) reactions on nuclear targets at ideal recoilless condition. We find that the smaller distortion effect in the (γ,p) reaction enables us to investigate properties of the mesons created deeply inside nucleus more clearly. We also consider excitation of scalar-isos

T. P. Polak, T. K. Kopec

We study the quantum phase transitions in two-dimensional arrays of Josephson-couples junctions with short range Josephson couplings (given by the Josephson energy) and the charging energy. We map the problem onto the solvable quantum generalization of the spherical model that improves over the mean-field theory method. The arrays are placed on the top of a

Rajesh Gopakumar

In previous work we have shown that large $N$ field theory amplitudes, in Schwinger parametrised form, can be organised into integrals over the stringy moduli space ${\cal M}_{g,n}\times R_{+}^n$. Here we flesh this out into a concrete implementation of open-closed string duality. In particular, we propose that the closed string worldsheet is reconstructed f

M. Guzzo, C. Moura

We investigate the possibility of detecting ultra-high energy cosmic tau-neutrinos by means of a process involving a double extensive air shower, the so-called Double-Bang Phenomenon. In this process a primary tau-neutrino interacts with an atmospheric quark creating a hadronic extensive air shower that contains a tau which subsequently decays creating a sec

S. M. A. Tabei, A. Bahraminasab, A. A. Masoudi, S. Mousavi

The Kardar-Parisi-Zhang (KPZ) equation with infinitesimal surface tension, dynamically develops sharply connected valley structures within which the height derivative is not continuous. We discuss the intermittency issue in the problem of stationary state forced KPZ equation in 1+1--dimensions. It is proved that the moments of height increments $C_a = < | h

F. Zamponi, F. Bonetto, L. F. Cugliandolo, J. Kurchan

We discuss an extension of the fluctuation theorem to stochastic models that, in the limit of zero external drive, are not able to equilibrate with their environment, extending results presented by Sellitto (cond-mat/9809186). We show that if the entropy production rate is suitably defined, its probability distribution function verifies the Fluctuation Relat

Ulrich Ellwanger, Cyril Hugonie

We compute the leading logarithmic radiative corrections to the lightest Higgs mass in the NMSSM involving the electroweak gauge couplings and in the NMSSM specific Yukawa couplings lambda and kappa (including all mixed combinations), which are induced by chargino, neutralino and Higgs boson loops. The effect of the NMSSM specific Yukawa couplings lambda and

S. Dag, S. Tongay, T. Yildirim, E. Durgun

We found that magnetic ground state of one-dimensional atomic chains of carbon-transition metal compounds exhibit half-metallic properties. They are semiconductors for one spin-direction, but show metallic properties for the opposite direction. The spins are fully polarized at the Fermi level and net magnetic moment per unit cell is an integer multiple of Bo

Victor Galitski, G. Refael, Matthew P. A. Fisher, T. Senthil

We study the low temperature behavior of an amorphous superconducting film driven normal by a perpendicular magnetic field (B). For this purpose we introduce a new two-fluid formulation consisting of fermionized field induced vortices and electrically neutralized Bogoliubov quasiparticles (spinons) interacting via a long-ranged statistical interaction. This

Kenji Toma, Ryo Yamazaki, Takashi Nakamura

We perform Monte Carlo simulations to study Ep-Eiso correlation in the context of a multiple subjet model (or inhomogeneous jet model) for gamma-ray bursts (GRBs), X-ray--rich GRBs (XRRs), and X-ray flashes (XRFs). For a single subjet, we find that Ep prop. Eiso^0.4 for large viewing angles. For the multiple subjet model in which all the subjets have the sam

Jounghun Lee, Yipeng Jing, Yasushi Suto

We present an analytic expression for the axis ratio distribution of triaxial dark matter halos driven from physical principles. Adopting the picture of triaxial collapse based on the Zel&#39;dovich approximation, we derive analytically both the minor-to-major and the conditional intermediate-to-major axis ratio distributions, and examine how they depend on

S. B. Kozitskiy

Double-diffusive convection in a horizontally infinite layer of a unit height in a large Rayleigh numbers limit is considered. From linear stability analysis it is shown, that the convection tends to have a form of travelling tall thin rolls with height 10-30 times larger than width. Amplitude equations of ABC type for vertical variations of amplitude of the

Kazuhiro Hikami

We study the Witten--Reshetikhin--Turaev SU(2) invariant for the Seifert manifold $S^3/Γ$ where $Γ$ is a finite subgroup of SU(2). We show that the WRT invariants can be written in terms of the Eichler integral of the modular forms with half-integral weight, and we give an exact asymptotic expansion of the invariants by use of the nearly modular property of

Adan Cabello, Jose M. Estebaranz, Guillermo Garcia-Alcaine

We present a method to obtain sets of vectors proving the Bell-Kochen-Specker theorem in dimension $n$ from a similar set in dimension $d$ ($3\leq d<n\leq 2d$). As an application of the method we find the smallest proofs known in dimension five (29 vectors), six (31) and seven (34), and different sets matching the current record (36) in dimension eight.

A. Bassi

This is a book review of the book: &#34;Quantum Theory as an Emergent Phenomenon&#34;, by Stephen L. Adler (Cambridge University Press - 2004)

Feng-Li Yan, Hai-Rui Huo

We suggest a method for teleporting an unknown quantum state. In this method the sender Alice first uses a Controlled-Not operation on the particle in the unknown quantum state and an ancillary particle which she wants to send to the receiver Bob. Then she sends ancillary particle to Bob. When Alice is informed by Bob that the ancillary particle is received,

Fabio Sciarrino, Veronica Secondi, Francesco De Martini

The quantum cloner machine maps an unknown arbitrary input qubit into two optimal clones and one optimal flipped qubit. By combining linear and non-linear optical methods we experimentally implement a scheme that, after the cloning transformation, restores the original input qubit in one of the output channels, by using local measurements, classical communic

Chikara Furusawa, Kunihiko Kaneko

The evolutionary origin of universal statistics in biochemical reaction network is studied, to explain the power-law distribution of reaction links and the power-law distributions of chemical abundances. Using cell models with catalytic reaction network, we find evidence that the power-law distribution in abundances of chemicals emerges by the selection of c

Davide Cora&#39;, Ferdinando Di Cunto, Paolo Provero, Lorenzo Silengo

BACKGROUND: Transcriptional regulation is a key mechanism in the functioning of the cell, and is mostly effected through transcription factors binding to specific recognition motifs located upstream of the coding region of the regulated gene. The computational identification of such motifs is made easier by the fact that they often appear several times in th

Tao Hong, Claire Cramer, Eryn Cook, Warren Nagourney

We report an observation of the weak $6^{1}$S$_{0}$-$6^3$P$_0$ transition in $^{171,173}$Yb as an important step to establish Yb as a primary candidate for future optical frequency standards, and to open up a new approach for qubits using the $^{1}$S$_{0}$ and $^3$P$_0$ states of Yb atoms in an optical lattice.

Franz-Guenter Winkler

For the special theory of relativity, the normalization problem is formulated as the question how observers in constant relative motion may reach an agreement on space and time scales. As the normalization problem does not receive a thorough treatment in the standard development of the theory, two possible solutions called normalization at rest and normaliza

Lorant Janosi, Harindar Keer, Ioan Kosztin, Thorsten Ritz

Light harvesting complexes 2 (LH2) from Rhodospirillum (Rs.) molischianum and Rhodopseudomonas (Rps.) acidophila form ring complexes out of eight or nine identical subunits, respectively. Here, we investigate computationally what factors govern the different ring sizes. Starting from the crystal structure geometries, we embed two subunits of each species int

Benjamin H. Singer, Miron Derchansky, Peter L. Carlen, Michal Zochowski

The dynamics underlying epileptic seizures are well understood. We present a novel analysis of seizure-like events (SLEs) in an \textit{ex vivo} whole hippocampus, as well as a modeling study that sheds light on the underlying network dynamics. We show that every SLE can be divided into two phases. During the first, SLE dynamics are driven by the intra-netwo

Debasis Dan, Chris Mueller, Kun Chen, James A. Glazier

The Cellular Potts Model (CPM) is a robust, cell-level methodology for simulation of biological tissues and morphogenesis. Both tissue physiology and morphogenesis depend on diffusion of chemical morphogens in the extra-cellular fluid or matrix (ECM). Standard diffusion solvers applied to the cellular potts model use finite difference methods on the underlyi

Shuang Zhang, Wenjun Fan, N. C. Panoiu, K. J. Malloy

Metal-based negative refractive index materials have been extensively studied in the microwave region. However, negative-index metamaterials have not been realized at near-IR or visible fre-quencies due to difficulties of fabrication and to the generally poorer optical properties of metals at these wavelengths. In this paper, we report the first fabrication

N. Bérerd, A. Chevarier, N. Moncoffre, P. Sainsot

This paper deals with the comparison between thermal and Fission Enhanced Diffusion (FED) of uranium into zirconia, representative of the inner face of cladding tubes. The experiments under irradiation are performed at the Institut Laue Langevin (ILL) in Grenoble using the Lohengrin spectrometer. A thin $^{235}UO\_2$ layer in direct contact with an oxidized

B. G. Sidharth

We argue that the Path Integral formulation of Feynman can be reconciled via a Planck scale underpinning for spacetime, with fuzzy spacetime considerations.

F. M. Nunes, A. M. Moro, A. M. Mukhamedzhanov, N. C. Summers

Modelling breakup reactions with exotic nuclei represents a challenge in several ways. The CDCC method (continuum discretized coupled channel) has been very successful in its various applications. Here, we briefly mention a few developments that have contributed to the progress in this field as well as some pertinent problems that remain to be answered.

R. R. Rodríguez--Guzmán, K. W. Schmid

The hole--spectral functions and from these the spectroscopic factors have been calculated in an Galilei--invariant way for the ground state wave functions resulting from spherical Hartree--Fock calculations with projection onto zero total linear momentum before the variation for the nuclei 4He, 12C, 16O, 28Si, 32S and 40Ca. The results are compared to those

A. Lavagno, P. Quarati

Density and temperature conditions in many stellar core (like the solar core) imply the presence of nonideal plasma effects with memory and long-range interactions between particles. This aspect suggests the possibility that the stellar core could not be in a global thermodynamical equilibrium but satisfies the conditions of a metastable state with a station

B. Chopard, S. Marconi

This paper shows that Physics is very close to the substitution-diffusion paradigm of symmetric ciphers. Based on this analogy, we propose a new cryptographic algorithm. Statistical Physics gives design principles to devise fast, scalable and secure encryption systems. In particular, increasing space dimension and considering larger data blocks improve both

Shuichi Inokuchi, Kazumasa Honda, Hyen Yeal Lee, Tatsuro Sato

Bijections between sets may be seen as discrete (or crisp) unitary transformations used in quantum computations. So discrete quantum cellular automata are cellular automata with reversible transition functions. This note studies on 1d reversible cellular automata with triplet local rules.

Chin-Sheng Wu

We present the detailed calculation of the infinitesimal operators and the boson operators for SU (3) in Cartan-Weyl basis. They have been used extensively as theoretical models for particle physics. We make a comparison between them, alongside with SL(3,c), which displays the concise appearance.

Julien Bect, Hana Baili, Gilles Fleury

We consider a Markov process on a Riemannian manifold, which solves a stochastic differential equation in the interior of the manifold and jumps according to a deterministic reset map when it reaches the boundary. We derive a partial differential equation for the probability density function, involving a non-local boundary condition which accounts for the ju

Claude LeBrun, L. J. Mason

We develop a global twistor correspondence for pseudo-Riemannian conformal structures of signature (++--) with self-dual Weyl curvature. Near the conformal class of the standard indefinite product metric on S^2 x S^2, there is an infinite-dimensional moduli space of such conformal structures, and each of these has the surprising global property that its null

Victor Bautista-Ancona, Javier Diaz-Vargas

It has been shown by Madden that there are only finitely many quadratic extensions of k(x), k a finite field, in which the ideal class group has exponent two and the infinity place of k(x) ramifies. We give a characterization of such fields that allow us to find a full list of all such field extensions for future reference. In doing so we correct some errors

Maria J. Cantero, Leandro Moral, Luis Velazquez

In this paper we obtain new results about the orthogonality measure of orthogonal polynomials on the unit circle, through the study of unitary truncations of the corresponding unitary multiplication operator, and the use of the five-diagonal representation of this operator. Unitary truncations on subspaces with finite co-dimension give information about the

Gregory C. Bell

It is relatively easy to construct a finitely generated group with infinite asymptotic dimension: the restricted wreath product of $\mathbb{Z}$ by $\mathbb{Z}$ provides an example. In light of this, it becomes interesting to consider the rate of growth of the asymptotic dimension function of a group. Loosely speaking, we measure the dimension on $λ$-scale an

Thomas Michael Keller

We establish several new bounds for the number of conjugacy classes of a finite group, all of which involve the maximal number c of conjugacy classes of a normal subgroup fixed by some element of a suitable subset of the group. To apply these formulas effectively, the parameter c, which in general is hard to control, is studied in some important situations.

Christopher Hillar, Charles R. Johnson, Ilya M. Spitkovsky

A generalized word in two letters $A$ and $B$ is an expression of the form $W=A^{α_1}B^{β_1}A^{α_2}B^{β_2}... A^{α_N}B^{β_N}$ in which the exponents $α_i$, $β_i$ are nonzero real numbers. When independent positive definite matrices are substituted for $A$ and $B$, we are interested in whether $W$ necessarily has positive eigenvalues. This is known to be the

Jonathan M. Groves, Yonatan Harel, Christopher J. Hillar, Charles R. Johnson

A real $n$-by-$n$ idempotent matrix $A$ with all entries having the same absolute value is called {\it absolutely flat}. We consider the possible ranks of such matrices and herein characterize the triples: size, constant, and rank for which such a matrix exists. Possible inequivalent examples of such matrices are also discussed.

Jonathan Pila

This note concerns the theoretical algorithmic problem of counting rational points on curves over finite fields. It explicates how the algorithmic scheme introduced by Schoof and generalized by the author yields an algorithm whose running time is uniformly polynomial time for curves in families.

Alexander Dranishnikov, Viktor Schroeder

We prove that a finitely generated, right-angled, hyperbolic Coxeter group can be quasiisometrically embedded into the product of n binary trees, where n is the chromatic number of the group. As application we obtain certain strongly aperiodic tilings of the Davis complex of these groups.

Elemer E Rosinger

In a series of publications in the early 1990s, L D Nel set up a study of non-normable topological vector spaces based on methods in category theory. One of the important results showed that the classical operations of derivative and integral in Calculus can in fact be obtained by a rather simple construction in categories. Here we present this result in a c

Meinolf Geck

In this paper, we study the Kazhdan--Lusztig cells of a Coxeter group $W$ in a ``relative&#39;&#39; setting, with respect to a parabolic subgroup $W_I \subseteq W$. This relies on a factorization of the Kazhdan--Lusztig basis $\{C_w\}$ of the corresponding (multi-parameter) Iwahori--Hecke algebra with respect to $W_I$. We obtain two applications to the ``asy

Daniele Guido, Tommaso Isola

It is proved that the family of equivalence classes of Lip-normed C*-algebras introduced by M. Rieffel, up to isomorphisms preserving the Lip-seminorm, is not complete w.r.t. the matricial quantum Gromov-Hausdorff distance introduced by D. Kerr. This is shown by exhibiting a Cauchy sequence whose limit, which always exists as an operator system, is not compl

Ki Hang Kim, Fred W. Roush

We show factorization of polynomials in one variable over the tropical semiring is in general NP-complete, either if all coefficients are finite, or if all are either 0 or infinity (Boolean case). We give algorithms for the factorization problem which are not polynomial time in the degree, but are polynomial time for polynomials of fixed degree. For two-vari

Christopher J. Hillar

We characterize polynomials having the same set of nonzero cyclic resultants. Generically, for a polynomial $f$ of degree $d$, there are exactly $2^{d-1}$ distinct degree $d$ polynomials with the same set of cyclic resultants as $f$. However, in the generic monic case, degree $d$ polynomials are uniquely determined by their cyclic resultants. Moreover, two r

Elias Katsoulis, Justin R. Peters

In this paper we study the nest representations of a strongly maximal TAF algebra, whose ranges contain non-zero compact operators. We introduce a particular class of such representations, the essential nest representations, and we show that their kernels coincide with the completely meet irreducible ideals. From this we deduce that there exist enough contra

Stephane Detournay, Domenico Orlando, P. Marios Petropoulos, Philippe Spindel

We present new exact three-dimensional black-string backgrounds, which contain both NS--NS and electromagnetic fields, and generalize the BTZ black holes and the black string studied by Horne and Horowitz. They are obtained as deformations of the Sl(2,R) WZW model. Black holes resulting from purely continuous deformations possess true curvature singularities

Thomas Fischbacher

The conjecture of a hidden $E_{10}$ symmetry of M-theory is supported by the close connection between the dynamics of D=11 supergravity near a spacelike singularity and a truncation of an one-dimensional $\sigma$-model with $E_{10}$ symmetry where all representations beyond SL(10) level $\ell=3$ are omitted. If this conjecture is right, higher-level represen

Yuji Nakawaki, Gary McCartor

We construct a new perturbative formulation of pure space-like axial gauge QED in which the inherent infrared divergences are regularized by residual gauge fields. For that purpose we perform our calculations in coordinates $x^μ=(x^+,x^-,x^1,x^2)$, where $x^+=x^0\sinθ+x^3\cos θ$ and $x^-=x^0\cosθ-x^3\sinθ$. $A_-=A^0\cosθ+A^3 \sinθ=n{\cdot}A=0$ is taken as th

A. V. Golovnev, L. V. Prokhorov

We study Nambu-Goto strings and branes. It is shown that they can be considered as continuous limits of ordered discrete sets of relativistic particles for which the tangential velocities are excluded from the action. The linear in unphysical momenta constraints are found. It allows to derive the evolution operators for the objects under consideration from t

B. Schenke, C. Greiner

It is investigated under which conditions an adiabatic adaption of the dynamic and spectral information of vector mesons to the changing medium in heavy ion collisions, as assumed in schematic model calculations and microscopic transport simulations, is a valid assumption. Therefore time dependent medium modifications of low mass vector mesons are studied wi

Ilja Dorsner, Pavel Fileviez Perez

We investigate predictions of a minimal realistic non-supersymmetric SU(5) grand unified theory. To accomplish unification and generate neutrino mass we introduce one extra Higgs representation--a 15 of SU(5)--to the particle content of the minimal Georgi-Glashow scenario. Generic prediction of this setup is a set of rather light scalar leptoquarks. In the c

Yutaka Hosotani

In higher dimensional gauge theory, dynamics of non-Abelian Aharonov-Bohm phases induces gauge symmetry breaking through the Hosotani mechanism. Higgs fields in the four-dimensional spacetime are identified with the extra-dimensional components of the gauge fields. Basics of the Hosotani mechanism are reviewed, and applied to the electroweak theory. The Higg

B. L. Ioffe, A. V. Samsonov

Radiative decays of the spin 1/2 baryonic resonances R with the decay mode R -> KN in case of small energy release are considered. Pentaquark is an example of such resonance. It is shown that in case of positive resonance parity corrections to the soft photon radiation formula are large even at low photon energies > 20 MeV and structure terms contributions m

Emanuel Katz, Ann E. Nelson, Devin G. E. Walker

Two paradigms for the origin of electroweak superconductivity are a weakly coupled scalar condensate, and a strongly coupled fermion condensate. The former suffers from a finetuning problem unless there are cancelations to radiative corrections, while the latter presents potential discrepancies with precision electroweak physics. Here we present a framework

Su Houng Lee, Hungchong Kim, Yongseok Oh

We investigate the decay modes of pentaquark baryons for both the antidecuplet and the octet states, which were recently claimed by Close and Dudek to be potentially narrow due to a hidden selection rule. We discuss how ideal mixing between the pentaquark octet and antidecuplet states can be related to the OZI rule, which also naturally leads to certain sele

M. M. Guzzo, C. A. Moura

We investigate the possibility of detecting cosmic ultra-high energy tau-neutrinos by means of a process involving a double extensive air shower, the so-called Double-Bang Phenomenon. In this process a primary tau-neutrino interacts with an atmospheric quark creating a first hadronic shower and a tau-lepton, which subsequently decays creating a second cascad

Daisuke Kadoh, Yoshio Kikukawa

A new technique is proposed to classify a topological field in abelian lattice gauge theories. We perform the classification by regarding the topological field as a local composite field of the gauge field tensor instead of the vector potential associated to an admissible gauge field. Our method reproduces the result obtained by the ordinary method in the in

Shin-Shan Yu

We present the first measurement of the ratio of branching fractions BR(LAMBDAB TO LAMBDAC MU NU)/BR(LAMBDAB to LAMBDAC PI) based on 171.5 pb-1 of ppbar collisions at the center of mass energy 1.96 TeV taken with the CDF-II detector. In addition, we present measurements of BR(B0 TO DSTAR MU NU)/BR(B0 TO DSTAR PI) and BR(B0 TO D MU NU)/BR(B0 TO D PI), which s

D0 Collaboration, V. Abazov

We present a measurement of the top quark pair ($t\bar{t}$) production cross section ($σ_{t\bar{t}}$) in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using 230 pb$^{-1}$ of data collected by the D0 experiment at the Fermilab Tevatron Collider. We select events with one charged lepton (electron or muon), missing transverse energy, and jets in the final state.

CLAS collaboration, L. Morand

The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large values of the four-momentum transfer (-t < 2.7 GeV2) to the proton. The contri

R. Balasubramanian, S. Babak, D. Churches, T. Cokelaer

A world-wide network of interferometric gravitational wave detectors is currently operational. The detectors in the network are still in their commissioning phase and are expected to achieve their design sensitivity over the next year or so. Each detector is a complex instrument involving many subsystems and each subsystem is a source of noise at the output

R. A. Konoplya, C. Molina

We investigate the response of the traversable wormholes to the external perturbations through finding their characteristic frequencies and time-domain profiles. The considered solution describes traversable wormholes between the branes in the two brane Randall-Sundrum model and was previously found within Einstein gravity with a conformally coupled scalar f

F. Shojai, A. Shirinifard

In this paper we have investigated the classical limit in Bohmian quantum cosmology. It is observed that in the quantum regime where the quantum potential is greater than the classical one, one has an expansion in terms of negative powers of the Planck constant. But in the classical limit there are regions having positive powers of the Planck constant, and r

A. Shojai, F. Shojai, N. Dadhich

We shall in the framework of Bohmian quantum gravity show that it is possible to find a {\it pure} quantum state which leads to the static Einstein universe whose classical counterpart is flat space--time. We obtain the solution not only in the long--wavelength approximation but also exactly.

M. K. Mak, T. Harko

We present a matrix method for obtaining new classes of exact solutions for Einstein&#39;s equations representing static perfect fluid spheres. By means of a matrix transformation, we reduce Einstein&#39;s equations to two independent Riccati type differential equations for which three classes of solutions are obtained. One class of the solutions correspondi

Hans L. Cycon, Thomas C. Schmidt, Matthias Waehlisch, Mark Palkow

In this paper we report on a multimedia communication system including a VCoIP (Video Conferencing over IP) software with a distributed architecture and its applications for teaching scenarios. It is a simple, ready-to-use scheme for distributed presenting, recording and streaming multimedia content. We also introduce and investigate concepts and experiments

Michael V. Feigel&#39;man, Lev B. Ioffe, Emil A. Yuzbashyan

We develop a theory of a pseudogap state appearing near the superconductor-insulator transition in strongly disordered metals with attractive interaction. We show that such an interaction combined with the fractal nature of the single particle wave functions near the mobility edge leads to an anomalously large single particle gap in the superconducting state

Sung Yong Park, D. Stroud

We show that, when a gold nanoparticle is coated by a thin layer of nematic liquid crystal, the deformation produced by the nanoparticle surface can enhance the splitting of the nanoparticle surface plasmon. We consider three plausible liquid crystal director configurations in zero electric field: boojum pair (north-south pole configuration), baseball (tetra

A. M. M. Pruisken, I. S. Burmistrov

In a recent Letter, Murzin et. al. [Phys. Rev. Lett., vol. 92, 016802 (2004)] investigated &#34;instanton effects&#34; in the magneto resistance data taken from samples with heavily Si-doped GaAs layers at low temperatures. This topological issue originally arose in the development of a microscopic theory of quantum Hall effect some 20 years ago. The investi

A. K. Tuchman, C. Orzel, A. Polkovnikov, M. A. Kasevich

We study the non-equilibrium evolution of the phase coherence of a Bose-Einstein condensate (BEC) in a one dimensional optical lattice, as the lattice is suddenly quenched from an insulating to a superfluid state. We observe slowly damped phase coherence oscillations in the regime of large filling factor (~100 bosons per site) at a frequency proportional to

J. Minar, L. Chioncel, A. Perlov, H. Ebert

We present a charge and self-energy self-consistent computational scheme for correlated systems based on the Korringa-Kohn-Rostoker (KKR) multiple scattering theory with the many-body effects described by the means of dynamical mean field theory (DMFT). The corresponding local multi-orbital and energy dependent self-energy is included into the set of radial

V. L. Marchenko, A. M. Savchenko

Coupled electron-nuclear oscillations in antiferromagnetics with anisotropy of &#34;light plane&#34; type in the strong external magnetic field are under consideration. The new mode ε_{2k} of these coupled oscillations is obtained for antiferromagnetic systems by using &#34;u-v&#34;-Bogolubov?s unitary transformations. The dynamic shift of the frequency of n

S. V. Belim

A field-theoretical description of the behavior of disordered, elastically isotropic, compressible systems characterized by two order parameters at the bicritical and tetracritical points is presented. The description is performed in the two-loop approximation in three dimensions . The renormalization group equations are analyzed, and the fixed points corres

S. Kamba, M. Berta, M. Kempa, J. Petzelt

Temperature dependences of the optic phonons in $\rm PbSc_{1/2}Ta_{1/2}O_3$ sol-gel films deposited on sapphire substrates were studied by means of Fourier transform far-infrared transmission spectroscopy in the temperature range 20-900\K. Four films displaying different B-site order with both ferroelectric and relaxor behavior were studied. In all cases the

Chisa Hotta, Masao Ogata, Hidetoshi Fukuyama

We study numerically the ground state properties of the one-dimensional quarter-filled strongly correlated electronic system interacting antiferromagnetically with localized $S=1/2$ spins. It is shown that the charge-ordered state is significantly stabilized by the introduction of relatively small coupling with the localized spins. When the coupling becomes

M. N. Kiselev, Yuval Gefen

We present a full fledged quantum mechanical treatment of the interplay between the charge and the spin zero-mode interactions in quantum dots. Quantum fluctuations of the spin-mode suppress the Coulomb blockade and give rise to non-monotonic behavior near this point. They also greatly enhance the dynamic spin susceptibility. Transverse fluctuations become i

S. Gupta, K. W. Murch, K. L. Moore, T. P. Purdy

We have produced Bose-Einstein condensates in a ring-shaped magnetic waveguide. The few-millimeter diameter non-zero bias ring is formed from a time-averaged quadrupole ring. Condensates which propagate around the ring make several revolutions within the time it takes for them to expand to fill the ring. The ring shape is ideally suited for studies of vortic

A. Lavagno, A. M. Scarfone, P. Narayana Swamy

On the basis of the recently proposed formalism [A. Lavagno and P.N. Swamy, Phys. Rev. E 65, 036101 (2002)], we show that the realization of the thermostatistics of q-deformed algebra can be built on the formalism of q-calculus. It is found that the entire structure of thermodynamics is preserved if we use an appropriate Jackson derivative instead of the ord

K. M. Indlekofer, J. Knoch, J. Appenzeller

In this article, we combine the modified electrostatics of a one-dimensional transistor structure with a quantum kinetic formulation of Coulomb interaction and nonequilibrium transport. A multi-configurational self-consistent Green&#39;s function approach is presented, accounting for fluctuating electron numbers. On this basis we provide a theory for the sim

Angel J. Moreno, Song-Ho Chong, Walter Kob, Francesco Sciortino

We present extensive molecular dynamics simulations of a liquid of symmetric dumbbells, for constant packing fraction, as a function of temperature and molecular elongation. For large elongations, translational and rotational degrees of freedom freeze at the same temperature. For small elongations only the even rotational degrees of freedom remain coupled to

Takaaki Koga, Yoshiaki Sekine, Junsaku Nitta

The gate-controlled electron spin interference was observed in nanolithographically defined square loop (SL) arrays fabricated using In$_{0.52}$Al$_{0.48}$As/In$_{0.53}$Ga$_{0.47}$As/In$_{0.52}$Al$_{0.48}$As quantum wells. In this experiment, we demonstrate electron spin precession in quasi-one-dimensional channels that is caused by the Rashba effect. It tur

P. D. Drummond, J. F. Corney, X. -J. Liu, H. Hu

We summarize recent theoretical results for the signatures of strongly correlated ultra-cold fermions in optical lattices. In particular, we focus on: collective mode calculations, where a sharp decrease in collective mode frequency is predicted at the onset of the Mott metal-insulator transition; and correlation functions at finite temperature, where we emp

S. Friedli, B. N. B. de Lima

In this note we consider long range $q$-states Potts models on $\mathbf{Z}^d$, $d\geq 2$. For various families of non-summable ferromagnetic pair potentials $ϕ(x)\geq 0$, we show that there exists, for all inverse temperature $β>0$, an integer $N$ such that the truncated model, in which all interactions between spins at distance larger than $N$ are suppresse

Jonathan P. K. Doye, Lars Meyer

Using a global optimization approach that directly searches for the composition of greatest stability, we have been able to find the particularly stable structures for binary Lennard-Jones clusters with up to 100 atoms for a range of Lennard-Jones parameters. In particular, we have shown that just having atoms of different size leads to a remarkable stabiliz