January 2007 arXiv papers — page 4

M. Tabrizi, A. V. Korol, A. V. Solov'yov, Walter Greiner

We discuss the features of a crystalline undulator of the novel type based on the effect of a planar channeling of ultra-relativistic electrons in a periodically bent crystals. It is demonstrated that an electron-based undulator is feasible in the tens of GeV range of the beam energies, which is noticeably higher than the energy interval allowed in a positro

Mohamed Ali Knani, Henri-Claude Boisson, André Giovannini, Taieb Lili

A two-dimensional simulation of a plane jet exhausting from a channel has been performed using the vortex in cell algorithm in the Reynolds number range of 100 to 900. The vorticity is generated on the wall of the entrance channel whose length has been fixed in order to obtain a fully developed velocity profile at the entry of the jet. The transient behaviou

Francesco Cianfrani, Orchidea Maria Lecian

The pioneering work of E.C.G. Stueckelberg is briefly analyzed: the formalism of the Stueckelberg field, able to describe a massive vector field, is reviewed, and some applications are presented. In particular, starting from his very first application, devoted to describe nuclear phenomena known in the Thirties, later attempts to demonstrate the renormalizab

David M. D. Smith, Jukka-Pekka Onnela, Neil F. Johnson

Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and -- after f

B. Atamaniuk, K. Zuchowski

We consider the influence of dust charge fluctuations on damping of the dust-ion-acoustic waves. It is assumed that all grains have equal masses but charges are not constant in time - they may fluctuate in time. The dust charges are not really independent of the variations in the plasma potentials. All modes will influence the charging mechanism, and feedbac

Barbara Atamaniuk, Krzysztof Zuchowski

There is a quickly increasing wealth of experimental data on so-called dusty plasmas i. e. ionized gases or usual plasmas that contain micron sized charged particles. Interest in these structures is driven both by their importance in many astrophysical as well as commercial situations. Among them are linear and nonlinear wave phenomena. We consider the influ

Andreas Flache, Michael W. Macy

Recent extensions of the Axelrod model of cultural dissemination (Klemm et al 2003) showed that global diversity is extremely fragile with small amounts of cultural mutation. This seemed to undermine the original Axelrod theory that homophily preserves diversity. We show that cultural diversity is surprisingly robust if we increase the tendency towards homop

Aravindan Semparithi, Srihari Keshavamurthy

We study the intramolecular vibrational energy redistribution (IVR) dynamics of an effective spectroscopic Hamiltonian describing the four coupled high frequency modes of CDBrClF. The IVR dynamics ensuing from nearly isoenergetic zeroth-order states, an edge (overtone) and an interior (combination) state, is studied from a state space diffusion perspective.

Kamal Barghout

I investigate a repulsive central universal force field on the behavior of celestial objects. I show its negative tidal effect on the solar orbits as experienced by Pioneer spacecrafts. I explain several cosmological effects in light of this force.

N. Sandeau, H. Giovannini

Optical transfer functions are presented for the 4pi' microscope. The effects of the size of the confocal pinhole on the three-dimensional resolution are studied. It is shown that the resolution of the 4Pi' microscope depends weakly on the pinhole size. This result suggest that the pinhole can be removed in order to increase the signal-to-noise ratio

J. J. Lunazzi

Archaeological mirrors from the Olmec civilization are described according to bibliographic references and to personal observations and photographs.

T. Papenbrock, H. A. Weidenmueller

We speak of chaos in quantum systems if the statistical properties of the eigenvalue spectrum coincide with predictions of random-matrix theory. Chaos is a typical feature of atomic nuclei and other self-bound Fermi systems. How can the existence of chaos be reconciled with the known dynamical features of spherical nuclei? Such nuclei are described by the sh

K. Pachucki, U. D. Jentschura, M. Pfutzner

The rate for the photon emission accompanying orbital 1S electron capture by the atomic nucleus is recalculated. While a photon can be emitted by the electron or by the nucleus, the use of the length gauge significantly suppresses the nuclear contribution. Our calculations resolve the long standing discrepancy of theoretical predictions with experimental dat

A. Gasparyan, J. Haidenbauer, C. Hanhart, K. Miyagawa

The perspects of utilizing the strangeness-production reaction gamma d -> K^+ Lambda n for the determination of the Lambda n low-energy scattering parameters are investigated. The spin observables that need to be measured in order to isolate the Lambda n singlet (1S0) and triplet (3S1) states are identified. Possible kinematical regions where the extraction

Pibero Djawotho

The main focus of the heavy flavor program at RHIC is to investigate the properties of the dense matter produced in heavy-ion collisions by studying its effect on open heavy flavor and quarkonia production. This in turn requires a detailed understanding of their production in elementary p+p collisions so that the dense matter effects can be later unfolded. I

Andrzej J. Maciejewski, Maria Przybylska

We show that if a holomorphic Hamiltonian system is holomorphically integrable in the non-commutative sense in a neighbourhood of a non-equilibrium phase curve which is located at a regular level of the first integrals, then the identity component of the differential Galois group of the variational equations along the phase curve is Abelian. Thus necessary c

Rodrigo A. Vicencio, Eugene Smirnov, Christian E. Rüter, Detlef Kip

Localized vectorial modes, with equal frequencies and mutually orthogonal polarizations, are investigated both analytically and experimentally in a one-dimensional photonic lattice with saturable nonlinearity. It is shown that these modes may span over many lattice elements and that energy transfer among the two components is both phase and intensity depende

Maria Przybylska

We consider natural Hamiltonian systems of $n>1$ degrees of freedom with polynomial homogeneous potentials of degree $k$. We show that under a genericity assumption, for a fixed $k$, at most only a finite number of such systems is integrable. We also explain how to find explicit forms of these integrable potentials for small $k$.

Dmitry Panchenko

Recently, Michel Talagrand computed the large deviations limit $\lim_{N\to\infty}(Na)^{-1}\log \e Z_N^a$ for the moments of the partition function $Z_N$ in the Sherrington-Kirkpatrick model for all real $a\geq 0.$ For $a\geq 1$ the limit is given by Guerra's inverse bound and this result extends the classical physicist's replica method that correspon

Tian Ma, Shouhong Wang

In this article, we derive a rigorous characterization of the boundary-layer and interior separations in the Taylor-Couette-Poiseuille (TCP) flow. The results obtained provide a rigorous characterization on how, when and where the propagating Taylor vortices (PTV) are generated. In particular, contrary to what is commonly believed, we show that the PTV do no

Vadim A. Markel, John C. Schotland

We provide a simple sufficient condition for convergence of Born series in the forward problem of optical diffusion tomography. The condition does not depend on the shape or spatial extent of the inhomogeneity but only on its amplitude.

Marina Ville

In this paper (S_n) is a sequence of surfaces immersed in a 4-manifold which converges to a branched surface S_0. Up to sign, μ^T_p (resp. μ^N_p) will denote the amount of curvature of the tangent bundles TS_n (resp. the normal bundles NS_n) which concentrates around a singular point p of S_0 when n goes to infinity. By a slight abuse of notation, we call μ_

Yves André

Deligne's regularity criterion for an integrable connection $\nabla$ on a smooth complex algebraic variety $X$ says that $\nabla$ is regular along the irreducible divisors at infinity in some fixed normal compactification of $X$ if and only if the restriction of $\nabla$ to every smooth curve on $X$ is fuchsian (i.e. has only regular singularities at inf

Yves André

We prove Malgrange's conjecture on the absence of confluence phenomena for integrable meromorphic connections. More precisely, if $ Y\to X$ is a complex-analytic fibration by smooth curves, $Z$ a hypersurface of $Y$ finite over $X$, and $\nabla$ an integrable meromorphic connection on $Y$ with poles along $Z$, then the function which attaches to {\smit x

Ian J Leary, Radu Stancu

We show that every fusion system on a p-group S is equal to the fusion system associated to a discrete group G with the property that every p-subgroup of G is conjugate to a subgroup of S.

Arnak Dalalyan, Anatoly Juditsky, Vladimir Spokoiny

The statistical problem of estimating the effective dimension-reduction (EDR) subspace in the multi-index regression model with deterministic design and additive noise is considered. A new procedure for recovering the directions of the EDR subspace is proposed. Under mild assumptions, $\sqrt n$-consistency of the proposed procedure is proved (up to a logarit

Hailong Dao

Let $T$ be a Noetherian ring and $f$ a nonzerodivisor on $T$. We study concrete necessary and sufficient conditions for a module over $R=T/(f)$ to be weakly liftable to $T$, in the sense of Auslander, Ding and Solberg. We focus on cyclic modules and get various positive and negative results on the lifting and weak lifting problems. For a module over $T$ we d

Chantal David, Tom Weston

We prove that, on average, elliptic curves over Q have finitely many primes p for which they possess a p-adic point of order p. We include a discussion of applications to companion forms and the deformation theory of Galois representations.

T. Fiedler, V. Kurlin

Fix a straight line L in Euclidean 3-space and consider the fibration of the complement of L by half-planes. A generic knot K in the complement of L has neither fiber quadrisecants nor fiber extreme secants such that K touches the corresponding half-plane at 2 points. Both types of secants occur in generic isotopies of knots. We give lower bounds for the num

Hans-Christian Graf von Bothmer, Kristian Ranestad

In this note, we use a natural desingularization of the conormal variety of the variety of n x n symmetric matrices of rank at most r to find a general formula for the algebraic degree in semidefinite programming.

Lothar Gerritzen

If a is a point in the domain of convergence of a planar power series f in a single variable x one con expand f into a planar power series in the variable (x-a). One arrives at the notion of planar analytic functions on any domain D in the complex plane. It can be described by sections of the sheaf of planar germs. The k-ary exponential series exp(k,x) has i

Jean-Marc Bardet, Pierre Bertrand

In certain applications, for instance biomechanics, turbulence, finance, or Internet traffic, it seems suitable to model the data by a generalization of a fractional Brownian motion for which the Hurst parameter $H$ is depending on the frequency as a piece-wise constant function. These processes are called multiscale fractional Brownian motions. In this cont

Jean-Marc Bardet, Paul Doukhan, Gabriel Lang, Nicolas Ragache

In this paper, a very useful lemma (in two versions) is proved: it simplifies notably the essential step to establish a Lindeberg central limit theorem for dependent processes. Then, applying this lemma to weakly dependent processes introduced in Doukhan and Louhichi (1999), a new central limit theorem is obtained for sample mean or kernel density estimator.

A. Bovdi, A. Szakacs

Let p be an odd prime, F the field of p elements and G a finite abelian p-group with an arbitrary involutory automorphism. Extend this automorphism to the group algebra FG and consider the unitary and the symmetric normalized units of FG. This paper provides bases and determines the invariants of the two subgroups formed by these units.

Antonio Lanteri, Roberto Munoz

Let $(X,L,V)$ be a triplet where $X$ is an irreducible smooth complex projective variety, $L$ is an ample and spanned line bundle on $X$ and $V\subseteq H^0(X,L)$ spans $L$. The discriminant locus $\Cal D(X,V) \subset |V|$ is the algebraic subset of singular elements of $|V|$. We study the components of $\Cal D(X,V)$ in connection with the jumping sets of $(

Olivier Biquard, Rafe Mazzeo

We consider the Einstein deformations of the reducible rank two symmetric spaces of noncompact type. If $M$ is the product of any two real, complex, quaternionic or octonionic hyperbolic spaces, we prove that the family of nearby Einstein metrics is parametrized by certain new geometric structures on the Furstenberg boundary of $M$.

H. -P. Pavel

As a first step towards a strong coupling expansion of Yang-Mills theory, the SU(2) Yang-Mills quantum mechanics of spatially constant gauge fields is investigated in the symmetric gauge, with the six physical fields represented in terms of a positive definite symmetric (3 x 3) matrix S. Representing the eigenvalues of S in terms of elementary symmetric poly

Daniel Robles-Llana, Martin Rocek, Frank Saueressig, Ulrich Theis

We discuss orientifold projections on superspace effective actions for hypermultiplets. We present a simple and new mechanism that allows one to find the Kahler potential and complex structure for the N=1 theory directly in terms of the parent N=2 theory. As an application, we demonstrate our method for Calabi-Yau orientifold compactifications of type IIB su

Nejat Tevfik Yilmaz

A revision of the torodial Kaluza-Klein compactification of the massless sector of the E(8)xE(8) heterotic string is given. Under the solvable Lie algebra gauge the dynamics of the O(p,q)/(O(p)xO(q)) symmetric space sigma model which is coupled to a dilaton, N abelian gauge fields and the Chern-Simons type field strength is studied in a general formalism. Th

Kourosh Nozari

Primordial Black Hole Remnants(PBHRs) can be considered as a primary source of cold dark matter. Hybrid inflation provides a possible framework for production of primordial black holes(PBHs) and these PBHs evaporate subsequently to produce PBHRs. In this paper we provide another framework for production of these PBHs. Using signature changing cosmological mo

Mauro Riccardi, Richard J. Szabo

We use twist deformation techniques to analyse the behaviour under area-preserving diffeomorphisms of quantum averages of Wilson loops in Yang-Mills theory on the noncommutative plane. We find that while the classical gauge theory is manifestly twist covariant, the holonomy operators break the quantum implementation of the twisted symmetry in the usual forma

D. A. Kulikov, R. S. Tutik, A. P. Yaroshenko

A new approach to the two-body problem based on the extension of the $SL(2,C)$ group to the $Sp(4,C)$ one is developed. The wave equation with various forms of including the interaction for the system of the spin-1/2 and spin-0 particles is constructed. For this system, it was found that the wave equation with a linear confinement potential involved in the n

Jens Erler

The prospects for electroweak precision physics at the LHC and the ILC are reviewed. This includes projections for measurements of the effective Z pole weak mixing angle, sin^2 theta_W (eff.), as well as top quark, W boson, and Higgs scalar properties. The upcoming years may also see very precise determinations of sin^2 theta_W (eff.) from lower energies.

S. Eidelman, M. Passera

This article reviews and updates the Standard Model prediction of the tau lepton g-2. Updated QED and electroweak contributions are presented, together with new values of the leading-order hadronic term, based on the recent low energy e+ e- data from BaBar, CMD-2, KLOE and SND, and of the hadronic light-by-light contribution. The total prediction is confront

Steve Geer, Olga Mena, Silvia Pascoli

If the value of $θ_{13}$ is within the reach of the upcoming generation of long-baseline experiments, T2K and NO$ν$A, we show that a low-energy neutrino factory, with peak energy in the few GeV range, would provide a sensitive tool to explore CP-violation and the neutrino mass hierarchy. We consider baselines with typical length 1000--1500 km. The unique per

Jorge Casalderrey-Solana

The experimental azimuthal dihadron distributions at RHIC show a double peak structure in the away side ($Δϕ= π\pm 1.2$ rad.) for intermediate $p_t$ particles. A variety of models have appeared trying to describe this modification. We will review most of them, with special emphasis in the Conical Flow scenario in which the observed shape is a consequence of

Gero von Gersdorff

We review electroweak symmetry breaking in supersymmetric models with a compact fifth dimension, the interval. We show how boundary conditions for hypermultiplets can be obtained dynamically by brane mass terms and present formulae for the spectrum in the presence of general bulk mass matrices. After giving a brief overview on the literature of models, we de

Zhun Lu, Bo-Qiang Ma, Ivan Schmidt

We calculate the non-zero Boer-Mulders functions of sea quarks inside the proton in a meson-baryon fluctuation model. The results show that the transverse spin effects of sea quarks in an unpolarized nucleon are sizable. Using the obtained antiquark Boer-Mulders functions, we estimate the $\cos 2 ϕ$ asymmetries in the unpolarized $pp$ and $p D$ Drell-Yan pro

We-Fu Chang, John N. Ng, Jackson M. S. Wu

We study a scale invariant $SU(2)\times U(1)_Y \times U(1)_s$ model which has only dimensionless couplings. The shadow $U(1)_s$ is hidden, and it interacts with the Standard Model (SM) solely through mixing in the scalar sector and kinetic mixing of the U(1) gauge bosons. The gauge symmetries are broken radiatively by the Coleman-Weinberg mechanism. Lifting

Kevin Dusling, Ismail Zahed

Recently the NA60 collaboration has reported the transverse mass spectra of dimuons coming from In-In collisions at 158 GeV/A. The measured yields display a strong invariant mass dependence not typical of radial flow, suggesting that different sources contribute in different mass regions. We interpret the dimuon transverse mass spectra from an early thermali

Michael Hohensee, Alex Glenday, Chih-Hao Li, Michael Edmund Tobar

In an earlier paper [1] (hep-ph/0408006), the bound on the Standard Model Extension photon-sector parameter $\tildeκ_{tr}$ [2] (hep-ph/0205211) set by the heavy-ion storage-ring experiment of Saathoff et al. [3] was incorrectly reported. We show that the correct bound on $\tildeκ_{tr}$ which resulted from this experiment is in fact $2.2\times 10^{-7}$.

John W. Norbury, Lawrence W. Townsend

A set of new, precise data have recently been made available by the NA49 collaboration for charged pion production in proton-proton and proton-Carbon reactions at 158 GeV. The current paper compares this new data to five currently available arithmetic parameterizations. Although a precise fit is not expected, two of the parameterizations do not work very wel

I. Rosell

This PhD thesis is a first step towards the control of the quantum corrections in the Resonance Chiral Theory, the suggested framework to handle QCD in the resonance region. After a theoretical introduction, Chapter 3 is devoted to calculate the vector form factor of the pion at the next-to-leading order in the 1/N(C) expansion. The ultraviolet behaviour of

The Belle collaboration

The Ds+- -> K+-K-+pi+- absolute branching fraction is measured using e+e- -> Ds*+- Ds1-+(2536) events collected by the Belle detector at the KEKB e+e- asymmetric energy collider. Using the ratio of yields when either the Ds1 or Ds* is fully reconstructed, we find Br(Ds+- -> K+-K-+pi+-)= (4.0+-0.4(stat)+-0.4(sys))%.

Geusa de A. Marques

In the paper [F. Nasseri, Phys. Lett. B 632 (2006) 151--154], F. Nasseri supposed that the value of the angular momentum for the Bohr's atom in the presence of the cosmic string is quantized in units of ℏ. Using this assumption it was obtained an incorrect expression for Bohr radius in this scenario. In this comment I want to point out that this as

Neil J. Cornish, Edward K. Porter

The Mock LISA Data Challenge is a worldwide effort to solve the LISA data analysis problem. We present here our results for the Massive Black Hole Binary (BBH) section of Round 1. Our results cover Challenge 1.2.1, where the coalescence of the binary is seen, and Challenge 1.2.2, where the coalescence occurs after the simulated observational period. The data

J. A. Valiente Kroon

Certain aspects of the behaviour of the gravitational field near null and spatial infinity for the developments of asymptotically Euclidean, conformally flat initial data sets are analysed. Ideas and results from two different approaches are combined: on the one hand the null infinity formalism related to the asymptotic characteristic initial value problem a

David Monniaux

We introduce a new method, combination of random testing and abstract interpretation, for the analysis of programs featuring both probabilistic and non-probabilistic nondeterminism. After introducing "ordinary" testing, we show how to combine testing and abstract interpretation and give formulas linking the precision of the results to the number of i

Solomija Buk, Andrij Rovenchak

In the paper, the definition of clause suitable for an automated processing of a Ukrainian text is proposed. The Menzerath-Altmann law is verified on the sentence level and the parameters for the dependences of the clause length counted in words and syllables on the sentence length counted in clauses are calculated for "Perekhresni Stezhky" ("The

Bruno Blanchet, Patrick Cousot, Radhia Cousot, Jerôme Feret

We show that abstract interpretation-based static program analysis can be made efficient and precise enough to formally verify a class of properties for a family of large programs with few or no false alarms. This is achieved by refinement of a general purpose static analyzer and later adaptation to particular programs of the family by the end-user through p

David Monniaux

The Astrée static analyzer is a specialized tool that can prove the absence of runtime errors, including arithmetic overflows, in large critical programs. Keeping analysis times reasonable for industrial use is one of the design objectives. In this paper, we discuss the parallel implementation of the analysis.

Thomas Jacobs, Aaron Harwood

The distribution of files using decentralized, peer-to-peer (P2P) systems, has significant advantages over centralized approaches. It is however more difficult to settle on the best approach for file sharing. Most file sharing systems are based on query string searches, leading to a relatively simple but inefficient broadcast or to an efficient but relativel

Fredrik Manne, Morten Mjelde, Laurence Pilard, Sébastien Tixeuil

The maximal matching problem has received considerable attention in the self-stabilizing community. Previous work has given different self-stabilizing algorithms that solves the problem for both the adversarial and fair distributed daemon, the sequential adversarial daemon, as well as the synchronous daemon. In the following we present a single self-stabiliz

M. A. Cazalilla, A. Iucci, T. Giamarchi

We study a system of two-dimensional Bose gases trapped in minima of a deep one-dimensional optical lattice potential. Increasing the tunneling amplitude between adjacent gases drives a deconfinement transition to a phase where coherence is established between neighboring two-dimensional gases. We compute the signature of this transition in the interference

Aline Y. Ramos, Hélio C. N. Tolentino, Narcizo M. Souza-Neto, Jean-Paul Itié

The local environment of manganese atoms in LaMnO3 under pressure up to 15.3 GPa has been studied by x-ray absorption spectroscopy. For pressures below 8 GPa, no change is detected within the MnO6 octahedra. Above this pressure a continuous reduction of the long Mn-O distance takes place, however the octahedral distortion persists over the whole pressure ran

M. Combescot, O. Betbeder-Matibet

The purpose of this paper is to show how the diagrammatic expansion in fermion exchanges of scalar products of $N$-composite-boson (``coboson'') states can be obtained in a practical way. The hard algebra on which this expansion is based, will be given in an independent publication. Due to the composite nature of the particles, the scalar products of

G. Herring, P. G. Kevrekidis, F. Williams, T. Christodoulakis

In this work we revisit the topic of two-dimensional Bose-Einstein condensates under the influence of time-dependent magnetic confinement and time-dependent scattering length. A moment approach reduces the examination of moments of the wavefunction (in particular, of its width) to an Ermakov-Pinney (EP) ordinary differential equation (ODE). We use the well-k

M. M. Korshunov, I. Eremin, A. Shorikov, V. I. Anisimov

Based on the {\it ab-initio} band structure for Na$_x$CoO$_2$ we derive the single-electron energies and the effective tight-binding description for the $t_{2g}$ bands using projection procedure. Due to the presence of the next-nearest-neighbor hoppings a local minimum in the electronic dispersion close to the $Γ$ point of the first Brillouin zone forms. Cor

F. Cordero, F. Craciun, C. Galassi

We present anelastic and dielectric spectroscopy measurements of PbZr(1-x)Ti(x)O(3) with 0.455 < x < 0.53, which provide new information on the low temperature phase transitions. The tetragonal-to-monoclinic transformation is first-order for x < 0.48 and causes a softening of the polycrystal Young&#39;s modulus whose amplitude may exceed the one at the cubic

L. C. Lapas, I. V. L. Costa, M. H. Vainstein, F. A. Oliveira

Ballistic transportation introduces new challenges in the thermodynamic properties of a gas of particles. For example, violation of mixing, ergodicity and of the fluctuation-dissipation theorem may occur, since all these processes are connected. In this work, we obtain results for all ranges of diffusion, i.e., both for subdiffusion and superdiffusion, where

Luca Salasnich, Sadhan K. Adhikari, Flavio Toigo

We investigate a dilute mixture of bosons and spin-polarized fermions in one-dimension. With an attractive Bose-Fermi scattering length the ground-state is a self-bound droplet, i.e. a Bose-Fermi bright soliton where the Bose and Fermi clouds are superimposed. We find that the quantum fluctuations stabilize the Bose-Fermi soliton such that the one-dimensiona

S. A. Zvyagin, J. Wosnitza, C. D. Batista, M. Tsukamoto

NiCl$_2$-4SC(NH$_2$)$_2$ (DTN) is a quantum S=1 chain system with strong easy-pane anisotropy and a new candidate for the Bose-Einstein condensation of the spin degrees of freedom. ESR studies of magnetic excitations in DTN in fields up to 25 T are presented. Based on analysis of the single-magnon excitation mode in the high-field spin-polarized phase and pr

J. Schmalhorst, A. Thomas, G. Reiss, X. Kou

The knowledge of chemical and magnetic conditions at the Co40Fe40B20 / MgO interface is important to interpret the strong annealing temperature dependence of tunnel magnetoresistance of Co-Fe-B / MgO / Co-Fe-B magnetic tunnel junctions, which increases with annealing temperature from 20% after annealing at 200C up to a maximum value of 112% after annealing a

Yuri Kornyushin

The General Thermodynamic Theory of Sintering, formulated by the author in 1998 is given. This theory is applied to the problem of swelling of materials under conditions of radiation. Driving forces, caused by the presence of the evolution of heat in the volume of a sample (electric contact, hf, inductive heating or penetrating radiation, e.g., neutrons coul

L. Baldassarre, A. Perucchi, E. Arcangeletti, D. Nicoletti

The electrodynamics near the metal-to-insulator transitions (MIT) induced, in V3O5 single crystals, by both temperature (T) and pressure (P) has been studied by infrared spectroscopy. The T- and P-dependence of the optical conductivity may be explained within a polaronic scenario. The insulating phase at ambient T and P corresponds to strongly localized smal

Eugenio Lippiello, Cataldo Godano, Lucilla de Arcangelis

We propose a branching process based on a dynamical scaling hypothesis relating time and mass. In the context of earthquake occurrence, we show that experimental power laws in size and time distribution naturally originate solely from this scaling hypothesis. We present a numerical protocol able to generate a synthetic catalog with an arbitrary large number

Yukitaka Ishimoto, Norio Kikuchi

We investigate how different microscopic interactions between semiflexible chain segments can qualitatively alter the physical properties of the condensed toroid. We propose a general form of the Hamiltonian of the toroid and discuss its analytic properties. For different interactions, the theory predicts different scaling behaviours of the mean toroidal and

Yukitaka Ishimoto, Norio Kikuchi

It now becomes apparent that condensed DNA toroid which emerges in a poor solvent condition can be realised in the framework of the non-linear sigma model on a line segment. In fact, the classical solutions of the model, i.e., of the bending potential exhibit toroidal forms, and fit well with the delta-function term of the attractive interaction. The propose

M. Ichimura, K. Tanikawa, S. Takahashi, G. Baskaran

The electronic structure of diluted magnetic semiconductors is studied, especially focusing on the hole character. The Haldane-Anderson model is extend to a magnetic impurity, and is analyzed in the Hartree-Fock approximation. Due to the strong hybridization of an impurity d-states with host p-states, it is shown that holes are created in the valence band, a

Hiroki Nakano, Yoshinori Takahashi, Masatoshi Imada

The Drude weight of the Hubbard model on the two-dimensional square lattice is studied by the exact diagonalizations applied to clusters up to 20 sites. We carefully examine finite-size effects by consideration of the appropriate shapes of clusters and the appropriate boundary condition beyond the imitation of employing only the simple periodic boundary cond

Shiro Kawabata, Satoshi Kashiwaya, Yasuhiro Asano, Yukio Tanaka

We have investigated macroscopic quantum tunneling (MQT) in in-plane high-Tc superconductor Josephson junctions and the influence of the nodal-quasiparticle and the zero energy bound states (ZES) on MQT. We have shown that the presence of the ZES at the interface between the insulator and the superconductor leads to strong Ohmic quasiparticle dissipation. Th

M. Aldana, V. Dossetti, C. Huepe, V. M. Kenkre

An important characteristic of flocks of birds, school of fish, and many similar assemblies of self-propelled particles is the emergence of states of collective order in which the particles move in the same direction. When noise is added into the system, the onset of such collective order occurs through a dynamical phase transition controlled by the noise in

Lauren A. MacArthur, Jesus Gonzalez, Stephane Courteau

We report preliminary results of the characterization of bulge and inner disk stellar populations for 8 nearby spiral galaxies using Gemini/GMOS. The long-slit spectra extend out to 1-2 disk scale lengths with S/N/Ang > 50. Two different model fitting techniques, absorption-line indices and full spectral synthesis, are found to weigh age, metallicity, and ab

Toshiya Ueta, Koji Murakawa, Margaret Meixner

The structure of the dusty circumstellar envelopes (CSEs) of proto-planetary nebulae (PPNs) reveals the mass-loss history of these sources and how such histories may differ for elliptical (SOLE) and bipolar (DUPLEX) PPNs. To study the PPN structures via dust-scattered linearly polarized starlight, we have compiled the imaging-polarimetric data for all 18 evo

Isaura Fuentes-Carrera, Margarita Rosado, Philippe Amram, Heikki Salo

We study the kinematics and dynamics of the M51-type interacting galaxy pair KPG 302 (NGC 3893/96). We analyse the distribution of the dark matter (DM) halo of the main galaxy in order to explore possible differences between DM halos of &#34;isolated&#34; galaxies and those of galaxies belonging to a pair. The velocity field of each galaxy was obtained using

C. M. Booth, T. Theuns, T. Okamoto

We describe a numerical implementation of star formation in disk galaxies, in which the conversion of cooling gas to stars in the multiphase interstellar medium is governed by the rate at which molecular clouds are formed and destroyed. In the model, clouds form from thermally unstable ambient gas and get destroyed by feedback from massive stars and thermal

Chun Xu, Norbert Pirzkal, Sangeeta Malhotra, James E. Rhoads

We present redshifts for 115 emission line objects in the Hubble Ultra Deep Field (HUDF) identified through the GRism ACS Program for Extragalactic Science (GRAPES) project using the slitless grism spectroscopy mode of the ACS Camera on the Hubble Space Telescope (HST). The sample was selected by an emission line search on all extracted 1-dimensional GRAPES

J. Kasparova, E. P. Kontar, J. C. Brown

We investigate the signature of the photospheric albedo contribution in solar flare hard X-ray spectra, the effect of low energy cutoffs in electron spectra, and the directivity of hard X-ray emission. Using Ramaty High Energy Solar Spectroscopic Imager (RHESSI) flare data we perform a statistical analysis of spatially integrated spectra and positions of sol

Ingo Kreykenbohm, Sonja Fritz, Nami Mowlavi, Joern Wilms

In this paper, we review the observational properties of two accreting X-ray pulsars, the persistent source 4U1907+09 and the transient V0332+53. Accreting X-ray pulsars are among the brightest sources in the X-ray sky and are frequently observed by Integral and other X-ray missions. Nevertheless they are still very enigmatic sources as fundamental questions

L. Foschini, G. Ghisellini, F. Tavecchio, A. Treves

We present all the publicly available data, from optical/UV wavelengths (UVOT) to X-rays (XRT, BAT), obtained from Swift observations of the blazar PKS 2155-304, performed in response to the rapid alert sent out after the strong TeV activity (up to 17 Crab flux level at E > 200 GeV) at the end of July 2006. The X-ray flux increased by a factor of 5 in the 0.

M. R. Cunningham, P. A. Jones, P. D. Godfrey, D. M. Cragg

We have used the Mopra Telescope to search for glycine and the simple chiral molecule propylene oxide in the Sgr B2 (LMH) and Orion KL, in the 3-mm band. We have not detected either species, but have been able to put sensitive upper limits on the abundances of both molecules. The 3-sigma upper limits derived for glycine conformer I are 3.7 x 10^{14} cm^{-2}

Jingen Xiang, Julia C. Lee, Michael A. Nowak

We present X-ray dust scattering halo results based on our 76 ks {\it Chandra} ACIS-S/HETGS observation of the LMXB dipping source 4U 1624-490. Through analysis of the halo light curves with 2-6 keV spectra over the persistent and dipping periods, we estimate a geometric distance of $\sim$15 kpc to 4U 1624-490. We also fit halo radial profiles with different

Koushik Ghosh, Probhas Raychaudhuri

A physical data (such as astrophysical, geophysical, meteorological etc.) may appear as an output of an experiment or it may come out as a signal from a dynamical system or it may contain some sociological, economic or biological information. Whatever be the source of a time series data some amount of noise is always expected to be embedded in it. Analysis o

Koushik Ghosh, Probhas Raychaudhuri

A physical (e.g. astrophysical, geophysical, meteorological etc.) data may appear as an output of an experiment or it may contain some sociological, economic or biological information. Whatever be the source of a time series data some amount of noise is always expected to be embedded in it. Analysis of such data in presence of noise may often fail to give ac

Simon Cantin, Mercedes Mollá, Carmelle Robert, Anne Pellerin

We characterize the stellar populations in the nuclear region of the barred spiral galaxy NGC 4900 using the integral field spectrometer OASIS and the synthesis code LavalSB and the code from Mollá & Garc\&#39;ıa-Vargas (2000) for the young ($< 10$ Myr) and the old stellar populations, respectively. The high spatial resolution of the instrument allows us to

Ching-Wa Yip, Alex S. Szalay, Andrew Connolly, Tamas Budavari

Using subspace methods, we study the distribution of physical components of galaxies in wavelength space. We find that it is valid to assume that the stellar and the gaseous components of galaxies span complementary subspaces. To first order, stellar and gaseous spectral features can be extracted from galaxy spectra through a simple matrix multiplication. By

Koushik Ghosh, Probhas Raychaudhuri

We have used Simple Denoising Algorithm using Wavelet Transform on the daily Forbush decrease data from the year 1967 to 2003. For this data we observe periodicity around 5-6, 11, 13, 15 and 24 years. For all the obtained peaks corresponding confidence levels are higher than 95%. We observe that the periodicity of around 5-6 years is common to solar flare da

N. J. T. Smith, A. S. Murphy, T. J. Sumner

Recent objections (Phys.Lett. B 637, 156) to the published Zeplin I limit (Astropart. Phys 23, 444) are shown to arise from misunderstandings of the calibration data and procedure, and a misreading of the data in one of the referenced papers.

M. J. Hardcastle, D. A. Evans, J. H. Croston

We have recently shown that X-ray observations of the population of `low-excitation&#39; radio galaxies, which includes most low-power, Fanaroff-Riley class I sources as well as some more powerful Fanaroff-Riley class II objects, are consistent with a model in which the active nuclei of these objects are not radiatively efficient at any waveband. In another

E. Troja, G. Cusumano, V. LaParola, V. Mangano

We present Swift observations of GRB 051109B, a soft long burst triggered by the Burst Alert Telescope (BAT). The soft photon index of the prompt emission suggest it is a X-ray Flash (XRF) or, at least, a X-ray Rich (XRR) burst. The X-ray lightcurve displays the canonical shape of many other GRBs, a double b roken power law with a small flare superimposed at