September 2007 arXiv papers — page 15

Michel Schweitzer

The goal of the memoir is to develop a new cohomology theory which encompasses De Rham and Dolbeault cohomology as well as Deligne Beilinson cohomology, in the context of general complex analytic manifolds. The special case of the Iwasawa manifold is investigated as a typical example of what occurs in the non Kähler case. Elementary applications to the Kodai

Scott C. Noble, Matthew W. Choptuik

We investigate spherically-symmetric, general relativistic systems of collapsing perfect fluid distributions. We consider neutron star models that are driven to collapse by the addition of an initially "in-going" velocity profile to the nominally static star solution. The neutron star models we use are Tolman-Oppenheimer-Volkoff solutions with an ini

N. Schwierz, I. Wiedenhover, A. Volya

The drastically expanded use of the Woods-Saxon potential in modern day nuclear physics and the availability of new nuclear data motivated us to review and optimize the parameters of this potential to the experimental single-nucleon spectra around the doubly-magic nuclei between $^{16}$O and $^{208}$Pb. We obtain a parameterization which is applicable over t

M. Akiyama, Y. Minowa, N. Kobayashi, K. Ohta

In order to reveal the stellar mass distribution of z~3 galaxies, we are conducting deep imaging observations of U-dropout Lyman Break Galaxies (LBGs) with Adaptive Optics (AO) systems in K-band, which corresponds to rest-frame V-band of z~3 galaxies. The results of the Subaru intensive-program observations with AO36/NGS/IRCS indicate that 1) the K-band peak

Ivar Martin, Ya. M. Blanter, A. F. Morpurgo

We study a new type of one-dimensional chiral states that can be created in bilayer graphene (BLG) by electrostatic lateral confinement. These states appear on the domain walls separating insulating regions experiencing the opposite gating polarity. While the states are similar to conventional solitonic zero-modes, their properties are defined by the unusual

R. Fresneda, D. Gitman

Path-integral representations for a scalar particle propagator in non-Abelian external backgrounds are derived. To this aim, we generalize the procedure proposed by Gitman and Schvartsman 1993 of path-integral construction to any representation of SU(N) given in terms of antisymmetric generators. And for arbitrary representations of SU(N), we present an alte

Alfred B. U'Ren, Yasser Jeronimo-Moreno, Jose H. Garcia-Gracia

In this paper we study the spectral (temporal) properties of heralded single photon wavepackets, triggered by the detection of an idler photon in the process of parametric downconversion. The generated single photons are studied within the framework of the chronocyclic Wigner function, from which the single photon spectral width and temporal duration can be

Paulo D. F. Gouveia, Alexander Plakhov, Delfim F. M. Torres

(English) In a previous work [Nonlinearity, 20:2271-2287, 2007; arXiv:math/0703895] it is investigated, by means of computational simulations, shapes of nonconvex bodies that maximize resistance to its motion on a rarefied medium, considering that bodies are moving forward and at the same time slowly rotating. Here the previous results are improved: we obtai

Delphine El Kharrat, Olivier Sandre, Régine Perzynski, Frédéric Chécot

A novel type of hybrid colloids is presented, based on the association of several polymeric systems and ferrofluids. On the one hand, we use inorganic nanoparticles made of magnetic iron oxide prepared at the LI2C, which response to a magnetic field of low intensity. On the other hand the organic part is made either of long linear polyacrylamide chains or of

T. J. Cox, Patrik Jonsson, Rachel S. Somerville, Joel R. Primack

We employ numerical simulations of galaxy mergers to explore the effect of galaxy mass ratio on merger--driven starbursts. Our numerical simulations include radiative cooling of gas, star formation, and stellar feedback to follow the interaction and merger of four disk galaxies. The galaxy models span a factor of 23 in total mass and are designed to be repre

M. Bastero-Gil, M. Tristram, J. Macias-Perez, D. Santos

We have studied preheating of field perturbations in a 3-dimensional lattice including the effect of scalar metric perturbations, in two generic models of inflation: chaotic inflation with a quartic potential, and standard hybrid inflation. We have prepared the initial state for the classical evolution of the system with vanishing vector and tensor metric pe

Fiona Murnaghan

We exhibit a basis for the space of spherical characters of a distinguished supercuspidal representation $π$ of a connected reductive $p$-adic group, subject to the assumption that $π$ is obtained via induction from a representation of an open compact mod centre subgroup. We derive an integral formula for each spherical character belonging to the basis. This

W. Luis Mochan, Carlos Villarreal

We obtain expressions for the Casimir energy and force following an approach which may be applied to cavities made up of arbitrary materials. In the case of planar cavities we obtain the well known Lifshitz formula. The approach is easily generalizable to other geometries.

A. A. Osipov, B. Hiller, J. Moreira, A. H. Blin

This work is a follow-up of our recent observation that in the SU(3) flavor limit with vanishing current quark masses the temperature for the chiral transition is substantially reduced by adding eight-quark interactions to the Nambu - Jona-Lasinio Lagrangian with U_A(1) breaking. Here we generalize the case to realistic light and strange quark masses and con

Jeffrey Hakim, Fiona Murnaghan

This paper studies the behavior of Jiu-Kang Yu's tame supercuspidal representations relative to involutions of reductive p-adic groups. Symmetric space methods are used to illuminate various aspects of Yu's construction. Necessary conditions for a tame supercuspidal representation of G to be distinguished by (the fixed points of) an involution of G a

Peter Erwin, Michael Pohlen, John E. Beckman

We present a study of 66 barred, early-type (S0-Sb) disk galaxies, focused on the disk surface brightness profile outside the bar region and the nature of Freeman Type I and II profiles, their origins, and their possible relation to disk truncations. This paper discusses the data and their reduction, outlines our classification system, and presents $R$-band

Chin B Su, Jun Kameoka

A forty-four pass fibre optic surface plasmon resonance sensor that enhances detection sensitivity according to the number of passes is demonstrated for the first time. The technique employs a fibre optic recirculation loop that passes the detection spot forty- four times, thus enhancing sensitivity by a factor of forty-four. Presently, the total number of p

Samuel E. Vazquez

In this article we show how to set up initial states in ${\cal N} =4$ SYM theory that correspond to high energy graviton collisions, leading to black hole formation in $AdS_5\times S^5$. For this purpose, we study states in the gauge theory that are dual to graviton wavepackets localized at the center of $AdS_5$, and carrying large angular momentum along the

Elena F. Sheka, Leonid A. Chernozatonskii

For the first time, an approach is suggested for the quantitative description of the electronic structure of single-walled carbon nanotubes and the prediction of active sites for the tube controlled functionalization in view of the tube length and ends structure. The approach is based on the tube characteristic feature connected with odd electrons and is ill

A. F. Ferrari, M. Gomes, A. C. Lehum, A. Yu. Petrov

Within the superfield formalism, we study the ultraviolet properties of the three-dimensional supersymmetric quantum electrodynamics. The theory is shown to be finite at all loops orders in a particular gauge.

T. Muñoz-Darias, I. G. Martinez-Pais, J. Casares, R. Cornelisse

We present simultaneous high time resolution (1-10 Hz) X-ray and optical observations of the persistent LMXBs Sco X-1 and V801 Ara(=4U 1636-536). In the case of Sco X-1 we find that the Bowen/HeII emission lags the X-ray light-curves with a light travel time of ~11-16s which is consistent with reprocessing in the donor star. We also present the detection of

Marcos Rosenbaum, J. David Vergara, L. Roman Juarez

We investigate the incorporation of space noncommutativity into field theory by extending to the spectral continuum the minisuperspace action of the quantum mechanical harmonic oscillator propagator with an enlarged Heisenberg algebra. In addition to the usual $\star$-product deformation of the algebra of field functions, we show that the parameter of noncom

Abel Klein, Peter Müller

We study the ac-conductivity in linear response theory for the Anderson tight-binding model. We define the electrical ac-conductivity and calculate the linear-response current at zero temperature for arbitrary Fermi energy. In particular, the Fermi energy may lie in a spectral region where extended states are believed to exist.

Simon Catterall, Toby Wiseman

We describe the conjectured holographic duality between Yang-Mills quantum mechanics and type IIa string theory. This duality allows us to use lattice Monte Carlo simulations to probe the physics of the gravitational theory - for example, at low energies it provides a computation of black hole entropy in terms of a sum over microstates of the dual gauge theo

Mario Bessa, Maria Carvalho

We consider an infinite dimensional separable Hilbert space and its family of compact integrable cocycles over a dynamical system f. Assuming that f acts in a compact Hausdorff space X and preserves a Borel regular ergodic measure which is positive on non-empty open sets, we conclude that there is a residual subset of cocycles within which, for almost every

B. Kliem, T. Toeroek

Reply to Comment on "Torus Instability" by J. Chen, Phys. Rev. Lett. 99, 099501 (2007). Refers to "Torus Instability" by Kliem and Toeroek, Phys. Rev. Lett. 96, 255002 (2006).

Deborah L. Padgett, Luisa M. Rebull, Karl R. Stapelfeldt, Nicholas L. Chapman

We present maps of 14.4 deg^2 of the Ophiuchus dark clouds observed by the Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS). These high quality maps depict both numerous point sources as well as extended dust emission within the star-forming and non-star-forming portions of these clouds. Using PSF-fitting photometry, we detect 5779 sou

Golam Mortuza Hossain

Cosmological constant a.k.a. dark energy problem is considered to be one major challenge in modern cosmology. Here we present a model where large scale structure formation causes spatially-flat FRW universe to fragment into numerous `FRW islands' surrounded by vacuum. We show that this mechanism can explain the origin of dark energy as well as the late t

L. Andrianopoli, S. Ferrara, A. Marrani, M. Trigiante

We connect the attractor equations of a certain class of N=2, d=5 supergravities with their (1,0), d=6 counterparts, by relating the moduli space of non-BPS d=5 black hole/black string attractors to the moduli space of extremal dyonic black string d=6 non-BPS attractors. For d = 5 real special symmetric spaces and for N = 4,6,8 theories, we explicitly comput

S. Mujumdar, A. F. Koenderink, T. Suenner, B. C. Buchler

We discuss experimental studies of the interaction between a nanoscopic object and a photonic crystal membrane resonator of quality factor Q=55000. By controlled actuation of a glass fiber tip in the near-field of a photonic crystal, we constructed a complete spatio-spectral map of the resonator mode and its coupling with the fiber-tip. On the one hand, our

Arlene C. Aguilar, Joannis Papavassiliou

We report on a special type of solutions for the gluon propagator of pure QCD, obtained from the corresponding non-linear Schwinger-Dyson equation formulated in the Feynman gauge of the background field method. These solutions reach a finite value in the deep infrared and may be fitted using a massive propagator, with the crucial characteristic that the effe

Y. Ramachers, D. Y. Stewart

We present methods to improve the energy resolution of single-channel, room-temperature Cadmium-Zinc-Telluride (CZT) detectors. A new preamplifier design enables the acquisition of the actual transient current from the crystals and straightforward data analysis methods yield unprecedented energy resolution for our test-detectors. These consist of an eV-CAPtu

Stephen Semmes

The focus here is on connected fractal sets with topological dimension 1 and a lot of topological activity, and their connections with analysis.

G. F. Chapline, P. Marecki

An exact solution of the vacuum Einstein equations with a cosmological constant is exhibited which can perhaps be used to describe the interior of compact rotating objects. The physical part of this solution has the topology of a torus, which may shed light on the origin of highly collimated jets from compact objects.

Norbert Zacharias, Bryan Dorland, Richard Bredthauer, Kasey Boggs

A full-wafer, 10,580 $\times$ 10,560 pixel (95 $\times$ 95 mm) CCD was designed and tested at Semiconductor Technology Associates (STA) with 9 um square pixels and 16 outputs. The chip was successfully fabricated in 2006 at DALSA and some performance results are presented here. This program was funded by the Office of Naval Research through a Small Business

Adam D. Myers, Gordon T. Richards, Robert J. Brunner, Donald P. Schneider

We present spectroscopy of binary quasar candidates selected from Data Release 4 of the Sloan Digital Sky Survey (SDSS DR4) using Kernel Density Estimation (KDE). We present 27 new sets of observations, 10 of which are binary quasars, roughly doubling the number of known $g < 21$ binaries with component separations of 3 to 6&#34;. Only 3 of 49 spectroscopica

Geraint Harker, Shaun Cole, Adrian Jenkins

We generate mock galaxy catalogues for a grid of different cosmologies, using rescaled N-body simulations in tandem with a semi-analytic model run using consistent parameters. Because we predict the galaxy bias, rather than fitting it as a nuisance parameter, we obtain an almost pure constraint on sigma_8 by comparing the projected two-point correlation func

Qutaibeh D. Katatbeh, Richard L. Hall, Nasser Saad

If a single particle obeys non-relativistic QM in R^d and has the Hamiltonian H = - Delta + f(r), where f(r)=sum_{i = 1}^{k}a_ir^{q_i}, 2\leq q_i < q_{i+1}, a_i \geq 0$, then the eigenvalues E = E_{n\ell}^{(d)}(λ) are given approximately by the semi-classical expression E = \min_{r > 0}[\frac{1}{r^2} + \sum_{i = 1}^{k}a_i(P_ir)^{q_i}]. It is proved that this

Tim A. Koslowski

In this brief note (written as a lengthy letter), we describe the construction of a representation for the Weyl-algebra underlying Loop Quantum Geometry constructed from a diffeomorphism variant state, which corresponds to a &#39;&#39;condensate&#39;&#39; of Loop Quantum Geometry, resembling a static spatial geometry. We present the kinematical GNS-represent

HARP Collaboration

A measurement of the double-differential $π^{\pm}$ production cross-section in proton--carbon, proton--copper and proton--tin collisions in the range of pion momentum $100 \MeVc \leq p < 800 \MeVc$ and angle $0.35 \rad \le θ<2.15 \rad$ is presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by prot

Mats Carlsson, Viggo H. Hansteen, Bart De Pontieu, Scott McIntosh

We use Hinode/SOT Ca II H-line and blue continuum broadband observations to study the presence and power of high frequency acoustic waves at high spatial resolution. We find that there is no dominant power at small spatial scales; the integrated power using the full resolution of Hinode (0.05&#39;&#39; pixels, 0.16&#39;&#39; resolution) is larger than the po

Brieuc Conan-Guez, Fabrice Rossi, Aïcha El Golli

In many real world applications, data cannot be accurately represented by vectors. In those situations, one possible solution is to rely on dissimilarity measures that enable sensible comparison between observations. Kohonen&#39;s Self-Organizing Map (SOM) has been adapted to data described only through their dissimilarity matrix. This algorithm provides bot

D. A. Rodrigues, T. P. Spiller, J. F. Annett, B. L. Györffy

The quantised Josephson junction equation that underpins the behaviour of charge qubits and other tunnel devices is usually derived through cannonical quantisation of the classical macroscopic Josephson relations. However, this approach may neglect effects due to the fact that the charge qubit consists of a superconducting island of finite size connected to

Jan Stern

I consider non standard EW couplings of light right-handed quarks to W and Z suggested in a systematic non decoupling bottom-up low-energy effective theory approach to possible extensions of the Standard Model. New experimental tests in K^L_{mu3} decays based on recent measurements and scalar form factor analysis are discussed. A successful NLO fit to the st

HARP Collaboration

Measurements of the double-differential $π^{\pm}$ production cross-section in the range of momentum $100 \MeVc \leq p < 800 \MeVc$ and angle $0.35 \rad \leq θ< 2.15 \rad$ in proton--beryllium, proton--aluminium and proton--lead collisions are presented. The data were taken with the HARP detector in the T9 beam line of the CERN PS. The pions were produced by

Timothy H. Boyer

The fact that the author of an excellent textbook on electromagnetism could be duped by &#34;hidden momentum&#34; vividly illustrates the problematic nature of its use.

Alexandrina Nenciu

Using adiabatic expansions formalism, upper bounds for interband transitions for Bloch electrons in slowly varying in time electric fields are obtained. These bounds imply the validity of one-band approximation on long time scales.

P. Francois, E. Depagne, V. Hill, M. Spite

Our aim is to measure accurate, homogeneous neutron-capture element abundances for the sample of 32 EMP giant stars studied earlier in this series, including 22 stars with [Fe/H] $< -$3.0. Based on high-resolution, high S/N spectra from the ESO VLT/UVES, 1D, LTE model atmospheres, and synthetic spectrum fits, we determine abundances or upper limits for the 1

J. Sanchez Almeida, L. Teriaca, P. Suetterlin, D. Spadaro

CONTEXT:The footpoints of quiet Sun Transition Region (TR) loops do not seem to coincide with the photospheric magnetic structures appearing in traditional low-sensitivity magnetograms. AIMS: To look for the so-far unidentified photospheric footpoints of TR loops using G-band bright points (BPs) as proxies for photospheric magnetic field concentrations. METH

A. Blum, C. Hagedorn, M. Lindner

We perform a systematic study of dihedral groups used as flavor symmetry. The key feature here is the fact that we do not allow the dihedral groups to be broken in an arbitrary way, but in all cases some (non-trivial) subgroup has to be preserved. In this way we arrive at only five possible (Dirac) mass matrix structures which can arise, if we require that t

Randal Douc, Eric Moulines, Jimmy Olsson

In this article we study asymptotic properties of weighted samples produced by the auxiliary particle filter (APF) proposed by pitt and shephard (1999). Besides establishing a central limit theorem (CLT) for smoothed particle estimates, we also derive bounds on the Lp error and bias of the same for a finite particle sample size. By examining the recursive fo

A. J. Green, W. A. Baan

The Square Kilometre Array (SKA) is the radio telescope of the next generation, providing an increase in sensitivity and angular resolution of two orders of magnitude over existing telescopes. Currently, the SKA is expected to span the frequency range 0.1-25 GHz with capabilities including a wide field-of-view and measurement of polarised emission. Such a te

Piotr B. Mucha, Milan Pokorny

We study the motion of the steady compressible heat conducting viscous fluid in a bounded three dimensional domain governed by the compressible Navier-Stokes-Fourier system. Our main result is the existence of a weak solution to these equations for arbitrarily large data. A key element of the proof is a special approximation of the original system guaranteei

W. A. Baan

Arp220 is a nearby system in final stages of galaxy merger with powerful ongoing star-formation at and surrounding the two nuclei. Arp 220 was detected in HI absorption and OH Megamaser emission and later recognized as the nearest ultra-luminous infrared galaxy also showing powerful molecular and X-ray emissions. In this paper we review the available radio a

E. Borriello, A. Cuoco, G. Mangano, G. Miele

The high energy neutrino detection by a km^3 Neutrino Telescope placed in the Mediterranean sea provides a unique tool to both determine the diffuse astrophysical neutrino flux and the neutrino-nucleon cross section in the extreme kinematical region, which could unveil the presence of new physics. Here is performed a brief analysis of possible NEMO site perf

Clara I. Osorio, Gabriel Molina-Terriza, Blanca G. Font, Juan P. Torres

We experimentally demonstrate that paired photons generated in different sections of a down-conversion cone, when some of the interacting waves show Poynting vector walk-off, carry different spatial correlations, and therefore a different degree of spatial entanglement. This is shown to be in agreement with theoretical results. We also discuss how this azimu

Bernat Corominas-Murtra, Sergi Valverde, Carlos Rodríguez-Caso, Ricard V. Solé

Complex networks with high numbers of nodes or links are often difficult to analyse. However, not all elements contribute equally to their structural patterns. A small number of elements (the hubs) seem to play a particularly relevant role in organizing the overall structure around them. But other parts of the architecture (such as hub-hub connecting element

M. Spaans, R. Meijerink, F. P. Israel, A. F. Loenen

The nuclei of ULIRGs harbor massive young stars, an accreting central black hole, or both. Results are presented for molecular gas that is exposed to X-rays (1-100 keV, XDRs) and far-ultraviolet radiation (6-13.6 eV, PDRs). Attention is paid to species like HCO+, HCN, HNC, OH, H2O and CO. Line ratios of HCN/HCO+ and HNC/HCN discriminate between PDRs and XDRs

Biswarup Mukhopadhyaya, Somasri Sen, Soumitra SenGupta

We consider bulk antisymmetric tensor fields of various ranks in a Randall-Sundrum scenario. We show that, rank-2 onwards, the zero-modes of the projections of these fields on the (3+1) dimensional visible brane become increasingly weaker as the rank of the tensor increases. All such tensor fields of rank 4 or more are absent from the dynamics in four dimens

Fabrice Rossi, Amaury Lendasse, Damien François, Vincent Wertz

Data from spectrophotometers form vectors of a large number of exploitable variables. Building quantitative models using these variables most often requires using a smaller set of variables than the initial one. Indeed, a too large number of input variables to a model results in a too large number of parameters, leading to overfitting and poor generalization

F. Molitor, D. Graf, C. Stampfer, T. Ihn

Graphite is a well-studied material with known electronic and optical properties. Graphene, on the other hand, which is just one layer of carbon atoms arranged in a hexagonal lattice, has been studied theoretically for quite some time but has only recently become accessible for experiments. Here we demonstrate how single- and multi-layer graphene can be unam

A. F. Loenen, W. A. Baan, M. Spaans

The observed molecular properties of a sample of FIR-luminous and OH megamaser (OH-MM) galaxies have been investigated. The ratio of high and low-density tracer lines is found to be determined by the progression of the star formation in the system. The HCO+/HCN and HCO+/HNC line ratios are good proxies for the density of the gas, and PDR and XDR sources can

Eric D. Kolaczyk, David B. Chua, Marc Barthelemy

Betweenness centrality is a metric that seeks to quantify a sense of the importance of a vertex in a network graph in terms of its &#34;control&#34; on the distribution of information along geodesic paths throughout that network. This quantity however does not capture how different vertices participate together in such control. In order to allow for the unco

M. Zukovic, D. T. Hristopulos

A Spartan random process (SRP) is used to estimate the correlation structure of time series and to predict (extrapolate) the data values. SRP&#39;s are motivated from statistical physics, and they can be viewed as Ginzburg-Landau models. The temporal correlations of the SRP are modeled in terms of `interactions&#39; between the field values. Model parameter

A. Tarchi, A. Brunthaler, C. Henkel, K. M. Menten

The standard unified scheme of active galactic nuclei requires the presence of high column densities of gas and dust potentially obscuring the central engine. So far, few direct subarcsecond resolution studies of this material have been performed toward radio galaxies. The goal of this paper is to elucidate the nuclear environment of the prototypical X-shape

Pascal Autissier

Let $X$ be a projective variety over a number field $K$ (resp. over $\mathbb{C}$). Let $H$ be the sum of ``sufficiently many positive divisors&#39;&#39; on $X$. We show that any set of quasi-integral points (resp. any integral curve) in $X-H$ is not Zariski dense.

Mr. Lambros Iossif

In regression theory, it is stated that the disturbance term follows the normal distribution when the sample size is large. In Professor J.Johnston&#39;s words: &#34;In view of the many factors involved, an appeal to the Central Limit Theorem would further suggest a normal distribution for u.&#34; This paper includes an elementary proof that the disturbance

Ivan Coluzza, Jean-Pierre Hansen

The stretching of brushes of long polymers grafted to a planar surface is investigated byMonte Carlo simulations in the limit of very high grafting densities, as achieved in recent experiments. The monomer density profiles are shown to deviate considerably from the parabolic limiting form predicted by self-consistent field theory. A rapid transition is obser

Alexander I. Bobenko, Yuri B. Suris

We discuss discretization of Koenigs nets (conjugate nets with equal Laplace invariants) and of isothermic surfaces. Our discretization is based on the notion of dual quadrilaterals: two planar quadrilaterals are called dual, if their corresponding sides are parallel, and their non-corresponding diagonals are parallel. Discrete Koenigs nets are defined as ne

Anders Gaarde

Using results by Melo, Nest, Schick, and Schrohe on the K-theory of Boutet de Monvel&#39;s calculus of boundary value problems, we show that the non-commutative residue introduced by Fedosov, Golse, Leichtnam, and Schrohe vanishes on projections in the calculus. This partially answers a question raised in a recent collaboration with Grubb, namely whether the

Preeti Parashar

The largest ensemble of qubits which satisfy the general transformation of equal superposition is obtained by different methods, namely, linearity, no-superluminal signalling and non-increase of entanglement under LOCC. We also consider the associated quantum random walk and show that all unitary balanced coins give the same asymmetric spatial probability di

Jadwiga Daszynska-Daszkiewicz

I discuss a prospect for mode identification from two-passband photometry of forthcoming BRITE space mission. Examples of photometric diagnostic diagrams are shown for three types of main sequence pulsating variables: $β$ Cephei, Slowly Pulsating B-type and $δ$ Scuti stars. I consider also taking into account the radial velocity data from simultaneous spectr

Kazuyuki Hara, Takahiro Yamada

We propose an optimization method of mutual learning which converges into the identical state of optimum ensemble learning within the framework of on-line learning, and have analyzed its asymptotic property through the statistical mechanics method.The proposed model consists of two learning steps: two students independently learn from a teacher, and then the

E. G. Bessonov

A method of enhanced optical cooling (EOC) based on nonlinear selective interaction between particles and theirs amplified undulator radiation wavelets (URW) in storage rings is discussed. It leads to non-exponential fast damping. The selectivity is arranged by a moving screen located on the image plane of the optical system projecting URW there.

Juan A. Acebron, Sergi Lozano, Alex Arenas

Many natural and artificial two-states signaling devices are connected forming networks. The information-processing potential of these systems is usually related to the response to weak external signals. Here, using a network of overdamped bistable elements, we study the effect of a heterogeneous complex topology on the signal response. The analysis of the p

J. -B. Bru, V. A. Zagrebnov

The superstable Weakly Imperfect Bose Gas {(WIBG)} was originally derived to solve the inconsistency of the Bogoliubov theory of superfluidity. Its grand-canonical thermodynamics was recently solved but not at {point of} the {(first order)} phase transition. This paper proposes to close this gap by using the large deviations formalism and in particular the a

J. Cuevas, B. A. Malomed, P. G. Kevrekidis

We introduce a two-dimensional (2D) discrete nonlinear Schrödinger (DNLS) equation with self-attractive cubic nonlinearity in a rotating reference frame. The model applies to a Bose-Einstein condensate stirred by a rotating strong optical lattice, or light propagation in a twisted bundle of nonlinear fibers. Two species of localized states are constructed: o

A. Rycerz, C. W. J. Beenakker

This is a numerical study of the conductance of an Aharonov-Bohm interferometer in a tight-binding model of graphene. Two single-mode ballistic point contacts with zigzag edges are connected by two arms of a hexagonal ring enclosing a magnetic flux $Φ$. The point contacts function as valley filters, transmitting electrons from one valley of the band structur

S. L. Moll, S. Mengel, R. de Grijs, L. J. Smith

We present new high spatial resolution HST/ACS imaging of NGC 1140 and high spectral resolution VLT/UVES spectroscopy of its central star-forming region. The central region contains several clusters, the two brightest of which are clusters 1 and 6 from Hunter, O&#39;Connell & Gallagher, located within star-forming knots A and B, respectively. Nebular analysi

M. Breger, S. M. Rucinski, P. Reegen

EE Cam is a previously little studied Delta Scuti pulsator with amplitudes between those of the HADS (High-Amplitude Delta Scuti stars) group and the average low-amplitude pulsators. Since the size of stellar rotation determines both which pulsation modes are selected by the star as well as their amplitudes, the star offers a great opportunity to examine the

G. V. Kraniotis

The exact (closed form) solutions of the equations of motion in the theory of general relativity that describe motion of test particle and photon in Kerr and Kerr-(anti) de Sitter spacetimes all involve the multivariable hypergeometric function of Lauricella $F_D$: Kraniotis [Class. Quantum Grav. {\bf 21} 2004, 4743; Class. Quantum Grav. {\bf 22} 2005, 4391;

M. C. Nucci, P. G. L. Leach

The last multiplier of Jacobi provides a route for the determination of families of Lagrangians for a given system. We show that the members of a family are equivalent in that they differ by a total time derivative. We derive the Schrödinger equation for a one-degree-of-freedom system with a constant multiplier. In the sequel we consider the particular examp

Thomas R. Weikl

Simple theoretical concepts and models have been helpful to understand the folding rates and routes of single-domain proteins. As reviewed in this article, a physical principle that appears to underly these models is loop closure.

M. Cristoforetti, P. Faccioli, M. Traini, J. W. Negele

The non-perturbative quark-gluon interaction depends significantly on the value of the quark mass. In particular, in the light quark mass regime, correlations are strongly influenced by dynamics associated to chiral symmetry breaking. We use the Interacting Instanton Liquid Model (IILM) as a tool to investigate the microscopic dynamical mechanisms which unde

C. Pierre

The main thesis of this paper deals with the interactions of a set of fermions which are described by one basic type of bilinear interactions,two symmetric semiobjects,three embedded shells and four fundamental (strong) gravito-electro-magnetic forces between left and right semiobjects,i.e semifermions.

Mariano Zelke

We reduce the best known approximation ratio for finding a weighted matching of a graph using a one-pass semi-streaming algorithm from 5.828 to 5.585. The semi-streaming model forbids random access to the input and restricts the memory to O(n*polylog(n)) bits. It was introduced by Muthukrishnan in 2003 and is appropriate when dealing with massive graphs.

Eva Riccomagno, Jim Q. Smith

Discrete Bayesian Networks have been very successful as a framework both for inference and for expressing certain causal hypotheses. In this paper we present a class of graphical models called the chain event graph (CEG) models, that generalises the class of discrete BN models. It provides a flexible and expressive framework for representing and analysing th

Bastian B. Brandt, Pushan Majumdar

We present a version of the Luescher-Weisz multilevel algorithm ideally suited for studying excited states of the QCD flux tube. While the original version achieved error reduction only in the temporal direction, the new algorithm reduces fluctuations in the sources as well. We report on the implementation of this algorithm as well as improvement over the ol

E. Brezin, S. Hikami

We consider a Gaussian random matrix theory in the presence of an external matrix source. This matrix model, after duality (a simple version of the closed/open string duality), yields a generalized Kontsevich model through an appropriate tuning of the external source. The n-point correlation functions of this theory are shown to provide the intersection numb

Eva Riccomagno, Jim Q Smith

The relationship between algebraic geometry and the inferential framework of the Bayesian Networks with hidden variables has now been fruitfully explored and exploited by a number of authors. More recently the algebraic formulation of Causal Bayesian Networks has also been investigated in this context. After reviewing these newer relationships, we proceed to

O. Tiret, F. Combes

The LCDM model is the most commonly admitted to describe our Universe. In spite of a great success with regard to the large scale structure formation, some problems are still unresolved at galactic scales. Alternative scenarios have to be explored such as modified gravity. We have developed an N-body code able to solve in a self consistent way the galactic d

Martin Kolar

The Chern-Moser normal form and its analog on finite type hypersurfaces in general do not respect symmetries. Extending the work of N. K. Stanton, we consider the local equivalence problem for symmetric Levi degenerate hypersurfaces of finite type in $\mathbb C^2$. The results give for all such hypersurfaces a complete normalization which respects the symmet

Ken Ohsuga

We performed two-dimensional radiation hydrodynamic simulations of supercritical accretion flows around neutron stars (NSs). In contrast with the accretion flows onto black holes (BHs), we find that the shell-shaped high-density regions form around the NSs, since the radiation force is enhanced in the innermost regions. The enhanced radiation force drives st

M. Ablikim, J. Z. Bai

Using 14.0\times 10^6 ψ(2S) events collected with the BES-II detector, the C-parity violating process J/psi->gamma gamma via psi(2S)->pi+pi- J/psi is studied. We determine a new upper limit for the J/psi->gamma gamma branching ratio of B(J/psi->gamma gamma)<2.2\times 10^{-5} at the 90% C.L., which is about 20 times lower than the previous measurement.

J. L. Ribeiro

At room temperature, GdMnO3 is a paraelectric and paramagnetic with a distorted perovskite structure of orthorhombic symmetry (space group Pnma). On cooling, it undergoes a phase transition sequence to a magnetic incommensurate phase (k=delta a*; Tc1=42K) and a A-type antiferromagnetic phase (Tc2=27K). At low temperatures (T<12K), a magnetic field applied al

Frank-Peter Schilling

The strategy for track based alignment of the CMS tracking and muon detectors is presented. After an overview over the used data samples, the general alignment strategy is presented, with a focus of the procedures envisaged at the start of data taking in 2008. The three currently used alignment algorithms are discussed and first results on their application

Ulrich W. Heinz, Gregory Kestin

We review J. Zimanyi&#39;s key contributions to the theoretical understanding of dynamical freeze-out in nuclear collisions and their subsequent applications to ultra-relativistic heavy-ion collisions, leading to the discovery of a freeze-out hierarchy where chemical freeze-out of hadron yields precedes the thermal decoupling of their momentum spectra. Follo

Fayyazuddin

The baryon decay modes of B,bar{B}-> N_{1}bar{N}_{2}(f), bar{N}_{1}N_{2}(bar{f}) provide a frame work to test CP-invariance in baryon sector. It is shown that in the rest frame of B, N_{1} and bar{N}_{2} come out with longitudnal polarization lambda_{1}=lambda_{2}=\pm 1 with decay width Gamma_{f}=Gamma_{f}^{++}+Gamma_{f}^{--} and the asymmetry parameter alph

J. J. Sanz-Cillero

In this talk we make an exhaustive analysis of the possible chiral invariant operators that may described the resonance decay S->pi pi. These provide at the same time the only available chiral invariant structures for the loop ultraviolet divergences in this amplitude. Independently of the order in perturbation theory, we find just one single-trace term (fou

Nathaël Alibaud, Pascal Azerad, Damien Isèbe

We investigate a non-local non linear conservation law, first introduced by A.C. Fowler to describe morphodynamics of dunes, see \cite{Fow01, Fow02}. A remarkable feature is the violation of the maximum principle, which allows for erosion phenomenon. We prove well-posedness for initial data in $L^2$ and give explicit counterexample for the maximum principle.