November 2007 arXiv papers — page 14

Alvaro Perales, Guifre Vidal

We study the evolution of one-dimensional quantum lattice systems when the ground state is perturbed by altering one site in the middle of the chain. For a large class of models, we observe a similar pattern of entanglement growth during the evolution, characterized by a moderate increase of significant Schmidt coefficients in all relevant bipartite decompos

Pasquale Calabrese, Andrea Pelissetto, Ettore Vicari

We consider the three-dimensional randomly diluted Ising model and study the critical behavior of the static and dynamic spin-spin correlation functions (static and dynamic structure factors) at the paramagnetic-ferromagnetic transition in the high-temperature phase. We consider a purely relaxational dynamics without conservation laws, the so-called model A.

Stéphane Devismes, Sébastien Tixeuil, Masafumi Yamashita

Self-stabilization is a strong property that guarantees that a network always resume correct behavior starting from an arbitrary initial state. Weaker guarantees have later been introduced to cope with impossibility results: probabilistic stabilization only gives probabilistic convergence to a correct behavior. Also, weak stabilization only gives the possibi

Ping Rong-Gang, F. A. Harris, for BES collaboration

Based on 14 million psi(2S) and 58 million J/psi events collected by the BESII detector, the leptonic decay of psi(2S) into $τ^+τ^-$, psi(2S) multi-body decays, chi_cJ decays, and J/psi hadronic decays are studied, and the branching fractions of these decays are reported. These results may shed light on the understanding of QCD.

Yemon Choi

Let $G$ be a discrete group. We give a decomposition theorem for the Hochschild cohomology of $\ell^1(G)$ with coefficients in certain $G$-modules. Using this we show that if $G$ is commutative-transitive, the canonical inclusion of bounded cohomology of $G$ into simplicial cohomology of $\ell^1(G)$ is an isomorphism.

Yen Lee Loh, Dao-Xin Yao, Erica W. Carlson

We study the thermodynamics of Ising spins on the triangular kagome lattice (TKL) using exact analytic methods as well as Monte Carlo simulations. We present the free energy, internal energy, specific heat, entropy, sublattice magnetizations, and susceptibility. We describe the rich phase diagram of the model as a function of coupling constants, temperature,

Nayantara Bhatnagar, Juan Vera, Eric Vigoda, Dror Weitz

Consider $k$-colorings of the complete tree of depth $\ell$ and branching factor $Δ$. If we fix the coloring of the leaves, as $\ell$ tends to $\infty$, for what range of $k$ is the root uniformly distributed over all $k$ colors? This corresponds to the threshold for uniqueness of the infinite-volume Gibbs measure. It is straightforward to show the existence

M. Bertola, S. Y. Lee

We describe the distribution of the first finite number of eigenvalues in a newly-forming band of the spectrum of the random Hermitean matrix model. The method is rigorously based on the Riemann-Hilbert analysis of the corresponding orthogonal polynomials. We provide an analysis with an error term of order N^(-2 h) where 1/h = 2 nu+2 is the exponent of non-r

Weizhe Zheng

Gabber deduced his theorem of independence of $l$ of intersection cohomology from a general stability result over finite fields. In this article, we prove an analogue of this general result over local fields. More precisely, we introduce a notion of independence of $l$ for systems of complexes of $l$-adic sheaves on schemes of finite type over a local field,

Hiroo Azuma

In this paper, we investigate the dynamics of the Bloch vector of a single two-level atom which interacts with a single quantized electromagnetic field mode according to the Jaynes-Cummings model, where the field is initially prepared in a thermal state. The time evolution of the Bloch vector S(t) seems to be in complete disorder because of the thermal distr

Arturo Pianzola, Daniel Prelat, Jie Sun

We use Galois descent to construct central extensions of twisted forms of split simple Lie algebras over rings. These types of algebras arise naturally in the construction of Extended Affine Lie Algebras. The construction also gives information about the structure of the group of automorphisms of such algebras.

Belen Paredes, Immanuel Bloch

We propose experimental schemes to create and probe minimum forms of different topologically ordered states in a plaquette of an optical lattice: Resonating Valence Bond, Laughlin and string-net condensed states. We show how to create anyonic excitations on top of these liquids and detect their fractional statistics. In addition, we propose a way to design a

C. S. Lam

The relation between fermion mixing and horizontal symmetry is discussed.

Amir Zait, Yehuda Hoffman, Isaac Shlosman

Dark matter (DM) halos formed in CDM cosmologies seem to be characterized by a power law phase-space density profile. The density of the DM halos is often fitted by the NFW profile but a better fit is provided by the Sersic fitting formula. These relations are empirically derived from cosmological simulations of structure formation but have not yet been expl

Sharanya Sur, Axel Brandenburg, Kandaswamy Subramanian

Using numerical simulations at moderate magnetic Reynolds numbers up to 220 it is shown that in the kinematic regime, isotropic helical turbulence leads to an alpha effect and a turbulent diffusivity whose values are independent of the magnetic Reynolds number, $\Rm$, provided $\Rm$ exceeds unity. These turbulent coefficients are also consistent with expecta

Serban T. Belinschi, Alexandru Nica

Let D be the space of non-commutative distributions of k-tuples of selfadjoints in a C*-probability space (for a fixed k). We introduce a semigroup of transformations B_t of D, such that every distribution in D evolves under the B_t towards infinite divisibility with respect to free additive convolution. The very good properties of B_t come from some special

Olivier Chenu, Nicolas Vuillerme, Alexandre Moreau-Gaudry, Anthony Fleury

We introduce the innovative technologies, based on the concept of "sensory substitution", we are developing in the fields of biomedical engineering and human disability. Precisely, our goal is to design, develop and validate practical assistive biomedical and/or technical devices and/or rehabilitating procedures for persons with disabilities, using a

Lorenzo Carlucci, Patrick Dehornoy, Andreas Weiermann

We construct long sequences of braids that are descending with respect to the standard order of braids (``Dehornoy order''), and we deduce that, contrary to all usual algebraic properties of braids, certain simple combinatorial statements involving the braid order are true, but not provable in the subsystems ISigma1 or ISigma2 of the standard Peano s

M. F. Nieva, N. Przybilla

Precise determinations of the chemical composition in early B-type stars consitute fundamental observational constraints on stellar and galactochemical evolution. Carbon is one of the most abundant metals in the Universe but analyses in early-type stars show inconclusive results, like large discrepancies between analyses of different lines in C II, a failure

J. P. Halpern, E. V. Gotthelf, J. Reynolds, S. M. Ransom

Following our discovery of radio pulsations from the newly recognized Anomalous X-ray Pulsar (AXP) 1E 1547.0-5408, we initiated X-ray monitoring with the Swift X-ray Telescope, and obtained a single target-of-opportunity observation with the Newton X-ray Multi-Mirror Mission (XMM-Newton). In comparison with its historic minimum flux of 3e-13 ergs cm^-2 s^-1,

Francesco Mainardi, Gianni Pagnini

The fundamental solution of the fractional diffusion equation of distributed order in time (usually adopted for modelling sub-diffusion processes) is obtained based on its Mellin-Barnes integral representation. Such solution is proved to be related via a Laplace-type integral to the Fox-Wright functions. A series expansion is also provided in order to point

G. Migliorini

We present a renormalization group study of two dimensional arrays of oscillators, with dissipative, short range interactions. We consider the case of non-identical oscillators, with distributed intrinsic frequencies within the array and study the steady-state properties of the system. In two dimensions no macroscopic mutual entrainment is found but, for ide

Tom Fisher

We explain how recent work on 3-descent and 4-descent for elliptic curves over Q can be combined to search for generators of the Mordell-Weil group of large height. As an application we show that every elliptic curve of prime conductor in the Stein-Watkins database has rank at least as large as predicted by the conjecture of Birch and Swinnerton-Dyer.

T. P. Singh

At present, there are two possible, and equally plausible, explanations for the physics of quantum measurement. The first explanation, known as the many-worlds interpretation, does not require any modification of quantum mechanics, and asserts that at the time of measurement the Universe splits into many branches, one branch for every possible alternative. T

J. -M. Alimi, V. D. Ivashchuk, V. N. Melnikov

An S-brane solution with two non-composite electric branes and a set of l scalar fields is considered. The intersection rule for branes corresponds to the Lie algebra A_2. The solution contains five factor spaces with the fifth one interpreted as ``our'' 3-dimensional space. It is shown that there exists a time interval where accelerating expansion o

A. N. Poddubny, L. Pilozzi, M. M. Voronov, E. L. Ivchenko

We propose a resonant one-dimensional quasicrystal, namely, a multiple quantum well (MQW) structure satisfying the Fibonacci-chain rule with the golden ratio between the long and short inter-well distances. The resonant Bragg condition is generalized from the periodic to Fibonacci MQWs. A dispersion equation for exciton-polaritons is derived in the two-wave

Evgueny Kochetov, Alvaro Ferraz, Rafael T. Pepino

We investigate analytically a connection between the t-J model and the strongly correlated Bardeen-Cooper-Schrieffer (BCS) Hamiltonian, with the effect of strong electron correlations accounted by the Gutzwiller projection. We show that in the immediate vicinity of half filling the projected 2D BCS Hamiltonian with strong pairing develops an antiferromagneti

Russell Zaretzki, Michael A. Gilchrist, William M. Briggs, Artin Armagan

This paper explores Bayesian inference for a biased sampling model in situations where the population of interest cannot be sampled directly, but rather through an indirect and inherently biased method. Observations are viewed as being the result of a multinomial sampling process from a tagged population which is, in turn, a biased sample from the original p

C. Kuelske, A. A. Opoku

We present a general method to derive continuity estimates for conditional probabilities of general (possibly continuous) spin models sub jected to local transformations. Such systems arise in the study of a stochastic time-evolution of Gibbs measures or as noisy observations. We exhibit the minimal necessary structure for such double-layer systems. Assuming

Oliver Muelken, Volker Pernice, Alexander Blumen

Quantum walks with long-range steps $R^{-γ}$ ($R$ being the distance between sites) on a discrete line behave in similar ways for all $γ\geq2$. This is in contrast to classical random walks, which for $γ>3$ belong to a different universality class than for $γ\leq 3$. We show that the average probabilities to be at the initial site after time $t$ as well as t

Antonio Lanteri, Raquel Mallavibarrena

Osculating spaces of decomposable scrolls (of any genus and not necessarily normal)are studied and their inflectional loci are related to those of their generating curves by using systematically an idea introduced by Piene and Sacchiero in the setting of rational normal scrolls. In this broader setting the extra components of the second discriminant locus -

D. Bollé, R. Heylen

We study the thermodynamic properties of spin systems with bond-disorder on small-world hypergraphs, obtained by superimposing a one-dimensional Ising chain onto a random Bethe graph with p-spin interactions. Using transfer-matrix techniques, we derive fixed-point equations describing the relevant order parameters and the free energy, both in the replica sym

T. J. Burns, F. E. Close

We derive relations among branching fractions in the exclusive decay of charmonia to light flavour meson pairs assuming factorization between the quark spin and spatial degrees of freedom. With the further assumption that these amplitudes can be described by flux-tube models, we assess prospects for production of hybrid mesons in charmonium decays.

S. Schanne, B. Cordier, D. Gotz, A. Gros

Gamma-ray bursts (GRB) sign energetic explosions in the Universe, occurring at cosmological distances. Multi-wavelength observations of GRB allow to study their properties and to use them as cosmological tools. In 2012 the space borne gamma-ray telescope ECLAIRs is expected to provide accurate GRB localizations on the sky in near real-time, necessary for gro

R. L. C. Starling, P. T. O'Brien, R. Willingale, K. L. Page

The origins of Gamma-ray Burst prompt emission are currently not well understood and in this context long, well-observed events are particularly important to study. We present the case of GRB 070616, analysing the exceptionally long-duration multipeaked prompt emission, and later afterglow, captured by all the instruments on-board Swift and by Suzaku WAM. Th

Swati Bhattacharya, Hsiao-Ping Hsu, Andrey Milchev, Vakhtang G. Rostiashvili

The adsorption of a single multi-block $AB$-copolymer on a solid planar substrate is investigated by means of computer simulations and scaling analysis. It is shown that the problem can be mapped onto an effective homopolymer adsorption problem. In particular we discuss how the critical adsorption energy and the fraction of adsorbed monomers depend on the bl

Frank Simon, James Kelsey, Michael Kohl, Richard Majka

Future measurements of the flavor-separated spin structure of the proton via parity-violating W boson production at RHIC require an upgrade of the forward tracking system of the STAR detector. This upgrade will allow the reconstruction of the charge sign of electrons and positrons produced from decaying W bosons. A design based on six large area triple GEM d

V. Blavats'ka, C. von Ferber, Yu. Holovatch

We analyze the impact of a porous medium (structural disorder) on the scaling of the partition function of a star polymer immersed in a good solvent. We show that corresponding scaling exponents change if the disorder is long-range-correlated and calculate the exponents in the new universality class. A notable finding is that star and chain polymers react in

B. Dóra, K. Ziegler, P. Thalmeier

The effect of weak potential and bond disorder on the density of states of graphene is studied. By comparing the self-consistent non-crossing approximation on the honeycomb lattice with perturbation theory on the Dirac fermions, we conclude, that the linear density of states of pure graphene changes to a non-universal power-law, whose exponent depends on the

Michael G. Eastwood

The purpose of this article is to motivate the study of invariant, and especially conformally invariant, differential pairings. Since a general theory is lacking, this work merely presents some interesting examples of these pairings, explains how they naturally arise, and formulates various associated problems.

I. Plans, A. Carpio, L. L. Bonilla

A novel analysis of homogeneous nucleation of dislocations in sheared two-dimensional crystals described by periodized discrete elasticity models is presented. When the crystal is sheared beyond a critical strain $F=F_{c}$, the strained dislocation-free state becomes unstable via a subcritical pitchfork bifurcation. Selecting a fixed final applied strain $F_

M. Guidal, S. Morrow

We discuss the interpretation of the $ep\to epρ^0$ process in terms of, on the one hand, Generalized Parton Distributions and, on the other hand, an effective hadronic model based on Regge theory.

Brian Moore, Josef Schicho, Clement M. Gosselin

In this paper, a new method to determine the complete set of dynamically balanced planar four-bar mechanims is presented. Using complex variables to model the kinematics of the mechanism, the dynamic balancing constraints are written as algebraic equations over complex variables and joint angular velocities. After elimination of the joint angular velocity va

Alberto Carrassi, Michael Ghil, Anna Trevisan, Francesco Uboldi

We study prediction-assimilation systems, which have become routine in meteorology and oceanography and are rapidly spreading to other areas of the geosciences and of continuum physics. The long-term, nonlinear stability of such a system leads to the uniqueness of its sequentially estimated solutions and is required for the convergence of these solutions to

Surachate Limkumnerd, Erik Van der Giessen

In a recent publication, we derived the mesoscale continuum theory of plasticity for multiple-slip systems of parallel edge dislocations, motivated by the statistical-based nonlocal continuum crystal plasticity theory for single-glide due to Yefimov et al. (2004b). In this dislocation field theory (DiFT) the transport equations for both the total dislocation

A. Moretti, R. Margutti, F. Pasotti, A. P. Beardmore

We aim to investigate the ability of simple spectral models to describe the GRB early afterglow emission. We performed a time resolved spectral analysis of a bright GRB sample detected by the Swift Burst Alert Telescope and promptly observed by the Swift X-ray Telescope,with spectroscopically measured redshift in the period April 2005 -- January 2007. The sa

Lars Kadison

It is shown that the cochain complex of relative Hochschild A-valued cochains of a depth two extension A | B under cup product is isomorphic as a differential graded algebra with the Amitsur complex of the coring S = End {}_BA_B over the centralizer R = A^B with grouplike element 1_S, which itself is isomorphic to the Cartier complex of S with coefficients i

J. Heinrichs

The mean and the variance of the logarithm of the conductance ($ln g$) in the localized regime in the one-dimensional Anderson model are calculated analytically for weak disorder, starting from the recursion relations for the complex reflection- and transmission amplitudes. The exact recursion relation for the reflection amplitudes is approximated by improve

H. -C. Lin, A. J. Fisher

We study the `local entanglement' remaining after filtering operations corresponding to imperfect measurements performed by one or both parties, such that the parties can only determine whether or not the system is located in some region of space. The local entanglement in pure states of general bipartite multidimensional continuous-variable systems can

D. A. Wisniacki, G. E. Murgida, P. I. Tamborenea

We exploit the concept of Landau-Zener transitions at avoided energy crossings as a quantum-control tool. In an avoided crossing the two quantum states interchange their characteristics as an external parameter is varied. Depending on the rate of change of the parameter it is possible to control the final state. We use this simple idea to travel along the en

G. M. Nikolopoulos, C. Lazarou, P. Lambropoulos

We investigate aspects of the dynamics of a continuous atom-laser scheme based on the merging of independently formed atomic condensates. Our theoretical analysis covers the Markovian as well as the non-Markovian operational regimes, and is based on a semiclassical (mean-field) two-mode model. The role of the relative phase between the two condensates and th

Christiane Helling

We calculate the formation of dust clouds in atmospheres of giant gas-planets. The chemical structure and the evolution of the grain size distribution in the dust cloud layer is discussed based on a consistent treatment of seed formation, growth/evaporation and gravitational settling. Future developments are shortly addressed.

S. Chaturvedi, G. Marmo, N. Mukunda, R. Simon

We give two explicit construction for the carrier space for the Schwinger representation of the group $S_n$. While the first relies on a class of functions consisting of monomials in antisymmetric variables, the second is based on the Fock space associated with the Greenberg algebra.

Sascha Orlik

We determine the fundamental group of period domains over finite fields.

Jorge Antezana, Enrique R. Pujals, Demetrio Stojanoff

Given an $r\times r$ complex matrix $T$, if $T=U|T|$ is the polar decomposition of $T$, then, the Aluthge transform is defined by $$ Δ(T)= |T|^{1/2} U |T |^{1/2}. $$ Let $Δ^{n}(T)$ denote the n-times iterated Aluthge transform of $T$, i.e. $Δ^{0}(T)=T$ and $Δ^{n}(T)=Δ(Δ^{n-1}(T))$, $n\in\mathbb{N}$. We prove that the sequence $\{Δ^{n}(T)\}_{n\in\mathbb{N}}$

Michael Zock, Stergos D. Afantenos

Speaking a language and achieving proficiency in another one is a highly complex process which requires the acquisition of various kinds of knowledge and skills, like the learning of words, rules and patterns and their connection to communicative goals (intentions), the usual starting point. To help the learner to acquire these skills we propose an enhanced,

B. Ziaja, H. Wabnitz, E. Weckert, T. Moeller

The kinetic Boltzmann equation is used to model the non-equilibrium ionization phase that initiates the evolution of atomic clusters irradiated with single pulses of intense vacuum ultraviolet radiation. The duration of the pulses is < 50 fs and their intensity in the focus is < 10^{14} W/cm^2. This statistical model includes various processes contributing t

B. Alver, B. B. Back, M. D. Baker, M. Ballintijn

In this paper, we investigate various ways of defining the initial source eccentricity using the Monte Carlo Glauber (MCG) approach. In particular, we examine the participant eccentricity, which quantifies the eccentricity of the initial source shape by the major axes of the ellipse formed by the interaction points of the participating nucleons. We show that

Andrew Stacey, Sarah Whitehouse

We provide a new algebraic description of the structure on the set of all unstable cohomology operations for a suitable generalised cohomology theory, E^*. Our description is as a graded and completed version of a Tall-Wraith monoid. The E^*-cohomology of a space X is a module for this Tall-Wraith monoid. We also show that the corresponding Hopf ring of unst

Zhao-Qing Feng, Gen-Ming Jin, Feng-Shou Zhang

The shell correction is proposed in the improved isospin dependent quantum molecular dynamics (ImIQMD) model, which plays an important role in heavy-ion fusion reactions near Coulomb barrier. By using the ImIQMD model, the static and dynamical fusion barriers, dynamical barrier distribution in the fusion reactions are analyzed systematically. The fusion and

O. Bohigas, J. X. de Carvalho, M. P. Pato

It is shown that the families of generalized matrix ensembles recently considered which give rise to an orthogonal invariant stable Lévy ensemble can be generated by the simple procedure of dividing Gaussian matrices by a random variable. The nonergodicity of this kind of disordered ensembles is investigated. It is shown that the same procedure applied to ra

Francesco Sorrentino, Edward Ott

In this paper we study synchronized motions in complex networks in which there are distinct groups of nodes where the dynamical systems on each node within a group are the same but are different for nodes in different groups. Both continuous time and discrete time systems are considered. We initially focus on the case where two groups are present and the net

Julia Kempe, Hirotada Kobayashi, Keiji Matsumoto, Thomas Vidick

The central question in quantum multi-prover interactive proof systems is whether or not entanglement shared between provers affects the verification power of the proof system. We study for the first time positive aspects of prior entanglement and show that entanglement is useful even for honest provers. We show how to use shared entanglement to parallelize

Javier Moreno Almeida, Ian D. Lawrie

According to quantum field theory, the inflaton equation of motion does not have the local form that is generally assumed for cosmological purposes. In particular, earlier investigations of the nonequilibrium dynamics of an inflaton that decays into scalar particles suggest that the loss of inflaton energy is not well approximated by the local friction term

P. Castorina

Because of colour confinement, the physical vacuum forms an event horizon for quarks and gluons; this can be crossed only by quantum tunneling, i.e., through the QCD counterpart of Hawking radiation by black holes. Since such radiation cannot transmit information to the outside, it must be thermal, of a temperature determined by the strong force at the confi

Simon M. Goodwin, Lutz Hille, Gerhard Röhrle

We consider the action of a parabolic subgroup of the General Linear Group on a metabelian ideal. For those actions, we classify actions with finitely many orbits using methods from representation theory.

Ricard V. Solé, Martí Rosas-Casals, Bernat Corominas-Murtra, Sergi Valverde

The power grid defines one of the most important technological networks of our times and sustains our complex society. It has evolved for more than a century into an extremely huge and seemingly robust and well understood system. But it becomes extremely fragile as well, when unexpected, usually minimal, failures turn into unknown dynamical behaviours leadin

Yu. A. Litvinov, F. Bosch, H. Geissel, J. Kurcewicz

We report on the first measurement of the $β^+$- and orbital electron capture decay rates of $^{140}$Pr nuclei with the most simple electron configurations: bare nuclei, hydrogen-like and helium-like ions. The measured electron capture decay constant of hydrogen-like $^{140}$Pr$^{58+}$ ions is about 50% larger than that of helium-like $^{140}$Pr$^{57+}$ ions

Y. Solomon

A separated net is a set of points which is relatively dense and uniformly discrete (another name for a Delone set). We are dealing with tilings and separated nets in Euclidean spaces and with the question whether a given separated net is biLipschitz to the integer lattice. In this paper we show, as an answer to a question of Burago and Kleiner, that the net

R. O. Umucalilar, Hui Zhai, M. O. Oktel

We consider a gas of non-interacting spinless fermions in a rotating optical lattice and calculate the density profile of the gas in an external confinement potential. The density profile exhibits distinct plateaus, which correspond to gaps in the single particle spectrum known as the Hofstadter butterfly. The plateaus result from insulating behavior wheneve

Julien Meyer

Whistled speech is a little studied local use of language shaped by several cultures of the world either for distant dialogues or for rendering traditional songs. This practice consists of an emulation of the voice thanks to a simple modulated pitch. It is therefore the result of a transformation of the vocal signal that implies simplifications in the freque

J. C. Gonzalez-Davila, F. Martin Cabrera, M. Salvai

We consider the energy functional on the space of sections of a sphere bundle over a Riemannian manifold (M, <,>) equipped with the Sasaki metric and we discuss the characterising condition for critical points. Likewise, we provide a useful method for computing the tension field in some particular situations. Such a method is shown to be adequate for many te

J. Ruiz-Fuertes, D. Errandonea, F. J. Manjon, D. Martinez-Garcia

The effect of pressure on the optical-absorption edge of CdIn2S4, MgIn2S4, and MnIn2S4 thiospinels at room temperature is investigated up to 20 GPa. The pressure dependence of their band-gaps has been analyzed using the Urbach rule. We have found that, within the pressure-range of stability of the low-pressure spinel phase, the band-gap of CdIn2S4 and MgIn2S

Richard Herrmann

Fractional calculus and q-deformed Lie algebras are closely related. Both concepts expand the scope of standard Lie algebras to describe generalized symmetries. For the fractional harmonic oscillator, the corresponding q-number is derived. It is shown, that the resulting energy spectrum is an appropriate tool e.g. to describe the ground state spectra of even

Stefano Pasquero

We analyze the impact of two equal billiard balls in three ideal situations: when the balls freely slide on the plane of the billiard, when they roll without sliding and when one of them freely slides and the other rolls. In all the cases we suppose that the contact between the balls is smooth. We base our analysis on some recent general theoretical results

P. Lenz, A. A. Pamyatnykh, M. Breger, V. Antoci

In this paper we investigate theoretical pulsation models for the delta Scuti star 44 Tau. The star was monitored during several multisite campaigns which confirmed the presence of radial and nonradial oscillations. Moreover, its exceptionally low rotational velocity makes 44 Tau particulary interesting for an asteroseismic study. Due to the measured log g v

Silvia Faggian

The paper concerns the study of the Pontryagin Maximum Principle for an infinite dimensional and infinite horizon boundary control problem for linear partial differential equations. The optimal control model has already been studied both in finite and infinite horizon with Dynamic Programming methods in a series of papers by the same author, or by Faggian an

P. Di Matteo, F. Combes, A. -L. Melchior, B. Semelin

We investigate, by means of numerical simulations, the kinematics of elliptical-spiral merger remnants. Counterrotation can appear both in coplanar and in non-coplanar retrograde mergers, and it is mostly associated to the presence of a disk component, which preserves part of its initial spin. In turn, the external regions of the two interacting galaxies acq

Vladimir Shevelev

We give a new short proof of the most simple relation between consecutive power sums of the first m positive integers.

Jean-André Marti

We introduce a general context involving a presheaf A and a subpresheaf B of A. We show that all previously considered cases of local analysis of generalized functions (defined from duality or algebraic techniques) can be interpretated as the B-local analysis of sections of A. But the microlocal analysis of the sections of sheaves or presheaves under conside

E. I. Guendelman

The axion photon system in an external magnetic field, when for example considered with the geometry of the experiments exploring axion photon mixing, displays a continuous axion-photon duality symmetry in the limit the axion mass is neglected. The conservation law that follows from this symmetry is obtained. The magnetic field interaction is seen to be equi

M. T. Yamashita, T. Frederico, L. Tomio

By introducing a mass asymmetry in a non-Borromean three-body system, without changing the energy relations, the virtual state pole cannot move from the negative real axis of the complex energy plane (with nonzero width) and become a resonance, because the analytical structure of the unitarity cuts remains the same.

V. Poireau

We present a mini-review on charm spectroscopy at the BaBar experiment. We first report on the $c\bar{s}$ meson spectrum, and present precise measurements of the $D_{s1}(2536)$ meson as well as the properties of the many new states discovered since 2003 ($D_{s0}^*(2317)$, $D_{s1}(2460)$, $D_{sJ}^*(2860)$, and $D_{sJ}(2700)$ mesons). We then discuss about cha

H. E. S. S. Collaboration, :, E. Moulin, C. Farnier

Dwarf Spheroidal galaxies are amongst the best targets to search for a Dark Matter annihilation signal. The annihilation of WIMPs in the center of Sagittarius dwarf spheroidal (Sgr dSph) galaxy would produce high energy gamma-rays in the final state. Observations carried out with the H.E.S.S. array of Imaging Atmospheric Cherenkov telescopes are presented. A

Konstantin Yu. Guslienko, Jun-Young Lee, Sang-Koog Kim

The motions of domain walls driven by magnetic field in soft magnetic nanostripes were calculated. The domain walls reveal steady motions in the low fields and oscillations of their internal structure above a critical field. A developed soliton model of the walls explains its dynamics by the motions of a limited number of magnetic topological solitons such a

Liu Hong, Jinzhi Lei

Scaling law for geometrical and dynamical quantities of biological molecules is an interesting topic. According to Flory&#39;s theory, a power law between radius of gyration and the length of homopolymer chain is found, with exponent 3/5 for good solvent and 1/3 for poor solvent. For protein in physiological condition, a solvent condition in between, a power

Xueliang Li, Yan Liu

In the paper &#34;Broersma and Hoede, {\it Path graphs}, J. Graph Theory {\bf 13} (1989) 427-444&#34;, the authors proposed a problem whether there is a triple of mutually nonisomorphic connected graphs which have an isomorphic connected $P_3$-graph. For a long time, this problem remains unanswered. In this paper, we give it a negative answer that there is n

Yong Wang, Bao-Gang Hu

This correspondence studies the basic problem of classifications - how to evaluate different classifiers. Although the conventional performance indexes, such as accuracy, are commonly used in classifier selection or evaluation, information-based criteria, such as mutual information, are becoming popular in feature/model selections. In this work, we propose t

Wei Biao Wu

We establish strong invariance principles for sums of stationary and ergodic processes with nearly optimal bounds. Applications to linear and some nonlinear processes are discussed. Strong laws of large numbers and laws of the iterated logarithm are also obtained under easily verifiable conditions.

V. N. Baier, V. M. Katkov

The spectral distribution of electron-positron pair created by photon and the spectral distribution of photons radiated from high-energy electron in an oriented single crystal is calculated using the method which permits inseparable consideration both of the coherent and incoherent mechanisms of two relevant processes. The method includes the action of field

Hideki Omori, Yoshiaki Maeda, Naoya Miyazaki, Akira Yoshioka

We propose a relatively new notion of two-valued elements, which arises naturally in constructing the star exponential functions of the quad-ratics in the Weyl algebra over the complex number field. This notion enables us to describe the group like objects of the set of star exponential functions of quadratics in the Weyl algebra.

J. Meaburn, J. A. López, M. G. Richer

New, very long (25&#39;), cuts of spatially resolved profiles of the Halpha and [N II] optical emission lines have been obtained over the face of the Helix planetary nebula, NGC 7293. These directions were chosen to supplement previous similar, though shorter, cuts as well as crossing interesting phenomena in this nebular envelope. In particular one new cut

Gui-Qiang Chen, Beixiang Fang

For an upstream supersonic flow past a straight-sided cone in $\R^3$ whose vertex angle is less than the critical angle, a transonic (supersonic-subsonic) shock-front attached to the cone vertex can be formed in the flow. In this paper we analyze the stability of transonic shock-fronts in three-dimensional steady potential flow past a perturbed cone. We esta

Hideki Omori, Yoshiaki Maeda, Naoya Miyazaki, Akira Yoshioka

Ideas from deformation quantization applied to algebras with one generator lead to methods to treat a nonlinear flat connection. It provides us elements of algebras to be parallel sections. The moduli space of the parallel sections is studied as an example of bundle-like objects with discordant (sogo) transition functions, which suggests us to treat movable

P. F. Wang, J. P. Li

This paper presents how to make use of the advantage of round-off error effect in some research areas. The float-point operation complies with the reproduce theorem without the external random perturbation. The computation uncertainty principle and the high nonlinear of chaotic system guarantee the numerical error is random and departure from the analytical

A. M. Souza, M. S. Reis, D. O. Soares-Pinto, I. S. Oliveira

The present work reports an experimental observation of thermal entanglement in a clusterized spin chain formed in the compound Na$_2$Cu$_5$Si$_4$O$_{14}$. The presence of entanglement was investigated through two measured quantities, an Entanglement Witness and the Entanglement of Formation, both derived from the magnetic susceptibility. It was found that p

Fabio Scardigli, Roberto Casadio

It has been recently debated whether a class of generalized uncertainty principles that include gravitational sources of error are compatible with the holographic principle in models with extra spatial dimensions. We had in fact shown elsewhere that the holographic scaling is lost when more than four space-time dimensions are present. However, we shall show

B. W. Borges, R. Baptista, C. Papadimitriou, O. Giannakis

We report the identification of cyclical changes in the orbital period of the eclipsing cataclysmic variable HT Cas. We measured new white dwarf mid-eclipse timings and combined with published measurements to construct an observed-minus-calculated diagram covering 29 years of observations. The data present cyclical variations that can be fitted by a linear p

Nguyen Tien Quang, D. D. Hanh, N. T. Thuy

In this paper, we have studied the axiomatics of {\it Ann-categories} and {\it categorical rings.} These are the categories with distributivity constraints whose axiomatics are similar with those of ring structures. The main result we have achieved is proving the independence of the axiomatics of Ann-category definition. And then we have proved that after ad

Heinrich Massold

For $θ$ a non-algebraic point on a quasi projective variety over a number field, I prove that $θ$ has an approximation by a series of algebraic points of bounded height and degree which is essentially best possible. Applications of this result will include a proof of a slightly strengthened version of the Philippon criterion, some new algebraic independence