November 2007 arXiv papers — page 40

Ali Mostafazadeh

I point out that if one defines the operator $U_R(t)$ as done by M. Znojil in his reply [arXiv:0711.0514v1] to my comment [arXiv:0711.0137v1] and also accepts the validity of the defining relation of $U_R(t)$ as given in his paper [arXiv:0710.5653v1], one finds that the time-evolution of the associated quantum system is not governed by the Schrödinger equati

Markus Diehl

I discuss the theoretical understanding of key measurements at HERA and their relevance for physics at LHC, focusing on recent developments for structure functions and for diffraction.

Daeho Lee, Ee Chang-Young, Myungseok Yoon

We consider charged rotating black holes localized on a three-brane in the DGP model. Assuming a $Z_2$-symmetry across the brane and with a stationary and axisymmetric metric ansatz on the brane, a particular solution is obtained in the Kerr-Schild form. This solution belongs to the accelerated branch of the DGP model and has the characteristic of the Kerr-N

U. D. Jentschura, A. Surzhykov, M. Lubasch, J. Zinn-Justin

For odd anharmonic oscillators, it is well known that complex scaling can be used to determine resonance energy eigenvalues and the corresponding eigenvectors in complex rotated space. We briefly review and discuss various methods for the numerical determination of such eigenvalues, and also discuss the connection to the case of purely imaginary coupling, wh

Bjorn Leder

The recently proposed construction of chiral fermions on lattices with boundaries is tested in an interacting theory up to first order of perturbation theory. We confirm that, in the bulk of the lattice, the chiral Ward identities take their continuum value up to cutoff effects without any tuning. Universal quantities are defined that have an expansion in th

W. Quint, B. Nikoobakht, U. D. Jentschura

With the advent of high-precision frequency combs that can bridge large frequency intervals, new possibilities have opened up for the laser spectroscopy of atomic transitions. Here, we show that laser spectroscopic techniques can also be used to determine the ground-state g factor of a bound electron: Our proposal is based on a double-resonance experiment, w

Jang Soo Kim

Using growth diagrams, we define a skew domino Schensted correspondence which is a domino analogue of the skew Robinson-Schensted correspondence due to Sagan and Stanley. The color-to-spin property of Shimozono and White is extended. As an application, we give a simple generating function for the weighted sum of skew domino tableaux, which is a generalizatio

M. Beccaria, G. J. Gounaris, J. Layssac, F. M. Renard

We write explicit and self-contained asymptotic expressions for the tensorial B, C and D Passarino-Veltman functions. These include quadratic and linear logarithmic terms, as well as subleading constant terms. Only mass-suppressed O(m^2/s) contributions are neglected. We discuss the usefulness of such expressions, particularly for studying one-loop effects i

G. B. Gumenchuk, I. V. Khyzhniy, A. N. Ponomaryov, M. A. Bludov

Electronically-induced desorption from solid Ar pre-irradiated by a low-energy electron beam was investigated by activation spectroscopy methods - photon-stimulated exoelectron emission and photon-stimulated luminescence in combination with spectrally-resolved measurements in the VUV range of the spectrum. Desorption of vibrationally excited argon molecules

Guglielmo Lacorata, Angelo Vulpiani

We show how a general formulation of the Fluctuation-Response Relation is able to describe in detail the connection between response properties to external perturbations and spontaneous fluctuations in systems with fast and slow variables. The method is tested by using the 360-variable Lorenz-96 model, where slow and fast variables are coupled to one another

Manda Banerji, Filipe B. Abdalla, Ofer Lahav, Huan Lin

We conduct a detailed analysis of the photometric redshift requirements for the proposed Dark Energy Survey (DES) using two sets of mock galaxy simulations and an artificial neural network code - ANNz. In particular, we examine how optical photometry in the DES grizY bands can be complemented with near infra-red photometry from the planned VISTA Hemisphere S

Harald O. Jeschke, L. Andrea Salguero, Badiur Rahaman, Christian Buchsbaum

In spin crossover materials, an abrupt phase transition between a low spin state and a high spin state can be driven by temperature, pressure or by light irradiation. Of a special relevance are Fe(II) based coordination polymers where, in contrast to molecular systems, the phase transition between a spin S=0 and a spin S=2 state shows a pronounced hysteresis

M. Elenius, M. Dzugutov

We examine structural relaxation in a supercooled glass-forming liquid simulated by NVE molecular dynamics. Time correlations of the total kinetic energy fluctuations are used as a comprehensive measure of the system's approach to the ergodic equilibrium. We find that, under cooling, the total structural relaxation becomes delayed as compared with the de

Norbert Nemec, David Tomanek, Gianaurelio Cuniberti

Carrier injection into carbon nanotubes and graphene nanoribbons, contacted by a metal coating over an arbitrary length, is studied by various means: Minimal models allow for exact analytic solutions which can be transferred to the original system with high precision. Microscopic ab initio calculations of the electronic structure at the carbon-metal interfac

Shoji Yamamoto, Jun Ohara

New varieties of quasi-one-dimensional halogen (X)-bridged transition-metal (M) complexes, (C_8_H_6_N_4_)[Pt(C_2_H_8_N_2_)X]_2_X(ClO_4_)_3_\cdotH_2_O (X=Br,Cl) and (C_10_H_8_N_2_)[Pt(C_4_H_13_N_3_)Br]_2_Br_4_\cdot2H_2_O, comprising two-leg ladders of mixed-valent platinum ions, are described in terms of a multiband extended Peierls-Hubbard Hamiltonian. The p

Thibault Damour, Piotr Jaranowski, Gerhard Schäfer

A Hamiltonian formulation is given for the gravitational dynamics of two spinning compact bodies to next-to-leading order ($G/c^4$ and $G^2/c^4$) in the spin-orbit interaction. We use a novel approach (valid to linear order in the spins), which starts from the second-post-Newtonian metric (in ADM coordinates) generated by two spinless bodies, and computes th

Shinsuke Kawai, Yuji Sugawara

We study a class of non-geometric string vacua realized as completely soluble superconformal field theory (SCFT). These models are defined as `interpolating orbifolds' of $K3 \times S^1$ by the mirror transformation acting on the $K3$ fiber combined with the half-shift on the $S^1$-base. They are variants of the T-folds, the interpolating orbifolds by T-

M. Grigorescu

Probability waves in the configuration space are associated with coherent solutions of the classical Liouville or Fokker-Planck equations. Distributions localized in the momentum space provide action waves, specified by the probability density and the generating function of the Hamilton-Jacobi theory. It is shown that by introducing a minimum distance in the

K. Vynck, E. Centeno, M. Le Vassor d'Yerville, D. Cassagne

We propose a practical and efficient solution for the coupling of light from integrated single-mode waveguides to supercollimating planar photonic crystals on conventional silicon-on-insulator platforms. The device consists of a rib waveguide, designed to sustain spatially extended single-modes and matched to a supercollimating photonic crystal, which has be

M. T. Downton, M. P. Kennett

The dynamics of a binary mixture of large and small discs are studied at temperatures approaching the glass transition using an analysis based on the topology of the Voronoi polygon surrounding each atom. At higher temperatures we find that dynamics is dominated by fluid-like motion that involves particles entering and exiting the nearest-neighbour shells of

Benedikt M. Pötscher

Confidence sets based on sparse estimators are shown to be large compared to more standard confidence sets, demonstrating that sparsity of an estimator comes at a substantial price in terms of the quality of the estimator. The results are set in a general parametric or semiparametric framework.

Kazunori Itakura, Osamu Morimatsu, Hiroshi Otomo

We discuss in detail the shear viscosity coefficient eta and the viscosity to entropy density ratio eta/s of a hadronic gas comprised of pions and nucleons. In particular, we study the effects of baryon chemical potential on eta and eta/s. We solve the relativistic quantum Boltzmann equations with binary collisions (pi pi, pi N, and NN) for a state slightly

Suman Sinha, Soumen Kumar Roy

Performance of Wang-Landau (W-L) algorithm in two continuous spin models is tested by determining the fluctuations in energy histogram. Finite size scaling is performed on a modified XY-model using different W-L sampling schemes. Difficulties faced in simulating relatively large continuous systems using W-L algorithm are discussed.

Mathias Lederer

Let $\mathscr{A}$ be a finite set of closed rational points in projective space, let $\mathscr{I}$ be the vanishing ideal of $\mathscr{A}$, and let $\mathscr{D}(\mathscr{A})$ be the set of exponents of those monomials which do not occur as leading monomials of elements of $\mathscr{I}$. We show that the size of $\mathscr{A}$ equals the number of axes contain

Kathryn Hess, Paul-Eugene Parent, Jonathan Scott

Generalizing work of Doi and of Idrissi, we define a coHochschild homology theory for chain coalgebras over any commutative ring and prove its naturality with respect to morphisms of chain coalgebras up to strong homotopy. As a consequence we obtain that if the comultiplication of a chain coalgebra $C$ is itself a morphism of chain coalgebras up to strong ho

C. Martin Gaskell, Rene W. Goosmann, Nelly I. Merkulova, Nikolay M. Shakhovskoy

Observations of the optical polarization of NGC 4151 in 1997-2003 show variations of an order of magnitude in the polarized flux while the polarization position angle remains constant. The amplitude of variability of the polarized flux is comparable to the amplitude of variability of the total U-band flux, except that the polarized flux follows the total flu

A. J. Scott

We show that weighted unitary 2-designs define optimal measurements on the system-ancilla output state for ancilla-assisted process tomography of unital quantum channels. Examples include complete sets of mutually unbiased unitary-operator bases. Each of these specifies a minimal series of optimal orthogonal measurements. General quantum channels are also co

Deepak Dhar, Samarth Chandra

We construct a class of lattices in three and higher dimensions for which the number of dimer coverings can be determined exactly using elementary arguments. These lattices are a generalization of the two-dimensional kagome lattice, and the method also works for graphs without translational symmetry. The partition function for dimer coverings on these lattic

Pietro Abate, Rajeev Goré, Florian Widmann

We present a tableau-based algorithm for deciding satisfiability for propositional dynamic logic (PDL) which builds a finite rooted tree with ancestor loops and passes extra information from children to parents to separate good loops from bad loops during backtracking. It is easy to implement, with potential for parallelisation, because it constructs a pseud

Peter G. Brooke, Karl-Peter Marzlin, James D. Cresser, Barry C. Sanders

We analyze the stability of super- and subradiant states in a system of identical two-level atoms in the near-Dicke limit, i.e., when the atoms are very close to each other compared to the wavelength of resonant light. The dynamics of the system are studied using a renormalized master equation, both with multipolar and minimal-coupling interaction schemes. W

Eliahu Levy, Orr Shalit

Let S be a dense sub-semigroup of the positive real numbers, and let X be a separable, reflexive Banach space. This note contains a proof that every weakly continuous contractive semigroup of operators on X over S can be extended to a weakly continuous semigroup over the positive real numbers. We obtain similar results for non-linear, non-expansive semigroup

P. Li, X. H. Zhong, L. Li, P. Z. Ning

The properties of $Σ$-hyperons in pure $Σ$ matter are studied with the finite-density quantum chromo-dynamics sum rule (QCDSR) approach. The $ΣΣ$ nuclear potential $U_Σ$ is most likely strongly attractive, it could be about -50 MeV or even more attractive at normal nuclear density. If this prediction is the case, the interactions between $Σ$-hyperons should

J. Okamoto, T. Okane, Y. Saitoh, K. Terai

Ca_1-xSr_xRuO_3, which is ferromagnetic for Sr concentration x > 0.3, has been studied by x-ray magnetic circular dichroism (XMCD) in Ru 3p and O 1s core-level x-ray absorption. XMCD signals appear at x ~ 0.3 and monotonically increases with x in the ferromagnetic phase. While the monotonic increase of the XMCD signals with x is of a typical Stoner-type, the

P. K. Pathak, R. N. Deb, N. Nayak, B. Dutta-Roy

We discuss generic spin squeezing operators (quadratic in angular momentum operators) capable of squeezing out quantum mechanical noise from a system of two-level atoms (spins) in a coherent state. Such systems have been considered by Kitagawa and Ueda (Refs. 2) in this context and a Hamiltonian of this nature governs the Lipkin model (Ref. 14) which is rele

Florian Dubath, Joseph Polchinski, Jorge V. Rocha

We extend our earlier model of the small scale structure of cosmic string networks through an improved treatment of the separation of long and short scales. We find that the production of small loops (at the gravitational radiation scale) is a robust feature of string networks, in addition to a population of loops near the horizon scale. We obtain quantitati

Yusuke Kuno

We present a formula expressing Earle's twisted 1-cocycle on the mapping class group of a closed oriented surface of genus >=2 relative to a fixed base point, with coefficients in the first homology group of the surface. For this purpose we compare it with Morita's twisted 1-cocycle which is combinatorial. The key is the computation of these cocycles

F. Bastianelli, U. Nucamendi, C. Schubert, V. M. Villanueva

Einstein-Maxwell theory implies the mixing of photons with gravitons in an external electromagnetic field. This process and its possible observable consequences have been studied at tree level for many years. We use the worldline formalism for obtaining an exact integral representation for the one-loop corrections to this amplitude due to scalars and fermion

Leonid, Kontorovich

Concentration bounds for non-product, non-Haar measures are fairly recent: the first such result was obtained for contracting Markov chains by Marton in 1996 via the coupling method. The work that followed, with few exceptions, also used coupling. Although this technique is of unquestionable utility as a theoretical tool, it is not always simple to apply. As

Chong-Xing Yue, Nan Zhang, Li Ding, Shi-Hai Zhu

The littlest Higgs model with T-parity ($LHT$ model) predicts the existence of the T-odd scalars ($ϕ^{\pm}$, $ϕ^{0}$, and $ϕ^{p}$). We consider production of these new particles associated with T-odd gauge bosons at the $LHC$. We find that the partonic process $q\bar{q'}\toϕ^{+}B_{H}$ can generate a number of the characteristic signal events with a charg

K. Vida, Zs. Kővári, M. Švanda, K. Oláh

We re-investigate UZ Librae spectra obtained at KPNO in 1998 and 2000. From the 1998 data we compose 11 consecutive Doppler images using the Ca I-6439, Fe I-6393 and Fe I-6411 lines. Applying the method of average cross-correlation of contiguous Doppler images we find anti-solar differential rotation with a surface shear of alpha ~ -0.03. The pilot applicati

Vladimir Nikiforov

We determine how large r-partite graphs can be found in r-uniform graphs with n vertices and Cn^r edges, where C is a slowly decreasing function of n. This refines results of Erdos from 1964.

NOMAD Collaboration, Q. K. Wu

We present a measurement of the muon neutrino-nucleon inclusive charged current cross-section, off an isoscalar target, in the neutrino energy range $2.5 \leq E_ν\leq 40$ GeV. The significance of this measurement is its precision, $\pm 4$% in $2.5 \leq E_ν\leq 10$ GeV, and $\pm 2.6$% in $10 \leq E_ν\leq 40$ GeV regions, where significant uncertainties in pre

Edgar Enochs, Sergio Estrada, J. R. Garcia-Rozas

We study Gorenstein categories. We show that such a category has Tate cohomological functors and Avramov-Martsinkovsky exact sequences connecting the Gorenstein relative, the absolute and the Tate cohomological functors. We show that such a category has what Hovey calls an injective model structure and also a projective model structure in case the category h

Gerald V. Dunne

Functional determinants of differential operators play a prominent role in theoretical and mathematical physics, and in particular in quantum field theory. They are, however, difficult to compute in non-trivial cases. For one dimensional problems, a classical result of Gel'fand and Yaglom dramatically simplifies the problem so that the functional determi

Alfredo von Reckow

In order to prove that the P of problems is different to the NP class, we consider the satisfability problem of propositional calculus formulae, which is an NP-complete problem. It is shown that, for every search algorithm A, there is a set E(A) containing propositional calculus formulae, each of which requires the algorithm A to take non-polynomial time to

Terence J. Tarnowsky

A discussion of results for short and long-range multiplicity correlations (forward-backward) are presented for several systems (Au+Au, Cu+Cu, and pp) and energies (e.g. $\sqrt{s_{NN}}$ = 200, 62.4, and $\approx$ 20 GeV). These correlations are measured with increasing values of a gap in pseudorapidity, from no gap at midrapidity to a separation of 1.6 units

Ofer Aharony, Zohar Komargodski

We study the operator product expansion (OPE) limit of correlation functions in field theories which possess string theory duals, from the point of view of the string worldsheet. We show how the interesting ("single-trace") terms in the OPE of the field theory arise in this limit from the OPE of the worldsheet theory of the string dual, using a domin

Stefano Ruffo

We briefly review some equilibrium and nonequilibrium properties of systems with long-range interactions. Such systems, which are characterized by a potential that weakly decays at large distances, have striking properties at equilibrium, like negative specific heat in the microcanonical ensemble, temperature jumps at first order phase transitions, broken er

M. Zaffalon, Aveek Bid, M. Heiblum, D. Mahalu

We report on the phase measurements on a quantum dot containing a single electron in the Kondo regime. Transport takes place through a single orbital state. Although the conductance is far from the unitary limit, we measure for the first time, a transmission phase as theoretically predicted of π/2. As the dot's coupling to the leads is decreased, with th

Eli Dwek, Frederic Galliano, Anthony P. Jones

Dusty hyperluminous galaxies in the early universe provide unique environments for studying the role of massive stars in the formation and destruction of dust. At redshifts above 6, when the universe was less than 1 Gyr old, dust could have only condensed in the explosive ejecta of Type II supernovae (SNe), since most of the progenitors of the AGB stars, the

Yeojin Chung, Avner Peleg

We study the combined effect of delayed Raman response and bit pattern randomness on pulse propagation in massive multichannel optical fiber communication systems. The propagation is described by a perturbed stochastic nonlinear Schrödinger equation, which takes into account changes in pulse amplitude and frequency as well as emission of continuous radiation

Hari P. Dahal, A. V. Balatsky, Jian-Xin Zhu

We study the impurity states in bilayer graphene in the unitary limit using Green's function method. Unlike in single layer graphene, the presence of impurities at two non-equivalent sites in bilayer graphene produce different impurity states which is understood as the change in the band structure due to interlayer hopping of electrons. The impurity stat

Doron Chelouche, Benjamin P. Koester, David V. Bowen

We report on the detection of reddening toward z ~ 0.2 galaxy clusters. This is measured by correlating the Sloan Digital Sky Survey cluster and quasar catalogs and by comparing the photometric and spectroscopic properties of quasars behind the clusters to those in the field. We find mean E(B-V) values of a few times 10^-3 mag for sight lines passing ~Mpc fr

Garcia de Andrade

Modifications on a recently introduced fast dynamo operator by Chiconne et al [Comm Math Phys 173, 379 (1995)] in compact 3D Riemannian manifolds allows us to shown that slow dynamos are Lagrangean stable, in the sense that the sectional curvature of the Riemann manifold vanishes. The stability of the holonomic filament in this manifold will depend upon the

Brad Hansen

The most commonly accepted explanation for the origin of hypervelocity stars in the halo of the Milky Way is that they are the result of tidal disruption of binaries by the massive black hole at the center of the Galaxy. We show that, if this scenario is correct, and if the original binary properties are similar to those in the local stellar neighbourhood, t

Deniz Gunduz, Elza Erkip

We consider transmission of a continuous amplitude source over an L-block Rayleigh fading $M_t \times M_r$ MIMO channel when the channel state information is only available at the receiver. Since the channel is not ergodic, Shannon's source-channel separation theorem becomes obsolete and the optimal performance requires a joint source -channel approach.

P. Kharb, D. Gabuzda, P. Shastri

We present very long baseline interferometry polarization images of an X-ray selected sample of BL Lacertae objects belonging to the first High Energy Astronomy Observatory (HEAO-1) and the ROSAT-Green Bank (RGB) surveys. These are primarily high-energy-peaked BL Lacs (HBLs) and exhibit core-jet radio morphologies on pc-scales. They show moderately polarized

Mitchell A. Harris

The unit distance embeddability of a graph, like planarity, involves a mix of constraints that are combinatorial and geometric. We construct a unit distance embedding for $H-e$ in the hope that it will lead to an embedding for $H$. We then investigate analytical methods for a general decision procedure for testing unit distance embeddability.

Terrence Napier, Mohan Ramachandran

Simple approaches to the proofs of the L^2 Castelnuovo-de Franchis theorem and the cup product lemma which give new versions are developed. For example, suppose u and v are two linearly independent closed holomorphic 1-forms on a bounded geometry connected complete Kaehler manifold X with v in L^2. According to a version of the L^2 Castelnuovo-de Franchis th

Dan Knopf

An important and natural question in the analysis of Ricci flow singularity formation in dimensions four and above is as follows: What are the weakest conditions that provide control of the norm of the Riemann curvature tensor? In this short note, we show that on a compact manifold, the trace-free Ricci tensor is controlled in a precise fashion by the other

Benoit Carry, Christophe Dumas, Marcello Fulchignoni, William J. Merline

We study the physical characteristics (shape, dimensions, spin axis direction, albedo maps, mineralogy) of the dwarf-planet Ceres based on high-angular resolution near-infrared observations. We analyze adaptive optics J/H/K imaging observations of Ceres performed at Keck II Observatory in September 2002 with an equivalent spatial resolution of ~50 km. The sp

Paul Balister, Béla Bollobás

In this paper we have shall generalize Shearer's entropy inequality and its recent extensions by Madiman and Tetali, and shall apply projection inequalities to deduce extensions of some of the inequalities concerning sums of sets of integers proved recently by Gyarmati, Matolcsi and Ruzsa. We shall also discuss projection and entropy inequalities and the

Nathalie Deruelle, Misao Sasaki, Yuuiti Sendouda

Taking advantage of the conformal equivalence of f(R) theories of gravity with General Relativity coupled to a scalar field we generalize the Israel junction conditions for this class of theories by direct integration of the field equations. We suggest a specific non-minimal coupling of matter to gravity which opens the possibility of a new class of branewor

Wen-Xiu Ma

The discrete variational identity under general bilinear forms on semi-direct sums of Lie algebras is established. The constant $γ$ involved in the variational identity is determined through the corresponding solution to the stationary discrete zero curvature equation. An application of the resulting variational identity to a class of semi-direct sums of Lie

Peter D. Hoff

This article discusses a latent variable model for inference and prediction of symmetric relational data. The model, based on the idea of the eigenvalue decomposition, represents the relationship between two nodes as the weighted inner-product of node-specific vectors of latent characteristics. This ``eigenmodel'' generalizes other popular latent var

Wasley S. Krogdahl

General relativity's successes and limitations are compared to those of special relativity.

Jeffrey L. Linsky, Barney J. Rickett, Seth Redfield

We study three quasar radio sources (B1257-326, B1519-273, and J1819+385) that show large amplitude intraday and annual scintillation variability produced by the Earth's motion relative to turbulent-scattering screens located within a few parsecs of the Sun. We find that the lines of sight to these sources pass through the edges of partially ionized warm

Michael P. Rupen, Amy J. Mioduszewski, Jennifer L. Sokoloski

We report high-resolution radio imaging of the recurrent nova RS Ophiuchi (RS Oph) during the first month of the 2006 outburst, using the Very Long Baseline Array (VLBA). Observations made on days 20.8 and 26.8 of the outburst show a synchrotron-emitting partial shell that is much brighter to the east than to the west. Assuming the broad component of the inf

Srividya Iyer-Biswas, F. Hayot, C. Jayaprakash

Transcriptional pulsing has been observed in both prokaryotes and eukaryotes and plays a crucial role in cell to cell variability of protein and mRNA numbers. The issue is how the time constants associated with episodes of transcriptional bursting impact cellular mRNA and protein distributions and reciprocally, to what extent experimentally observed distribu

R. Wesson, M. J. Barlow, X-W. Liu, P. J. Storey

We have analysed deep optical spectra of the `born-again' planetary nebula Abell 58 and its hydrogen-deficient knot, surrounding V605 Aql, which underwent a nova-like eruption in 1919. The electron temperature we derive for the central knot varies widely depending on the diagnostic used. The [O III] nebular-to-auroral transition ratio gives a temperature

Edward Frenkel, Dennis Gaitsgory

A module over an affine Kac--Moody algebra g^ is called spherical if the action of the Lie subalgebra g[[t]] on it integrates to an algebraic action of the corresponding group G[[t]]. Consider the category of spherical g^-modules of critical level. In this paper we prove that this category is equivalent to the category of quasi-coherent sheaves on the ind-sc

I. Zanella S. Guerini, S. B. Fagan, J. Mendes Filho, A. G. Souza Filho

By using first principles calculations we report a chemical doping induced gap in graphene. The structural and electronic properties of CrO$_3$ interacting with graphene layer are calculated using ab initio methods based on the density functional theory. The CrO$_3$ acts as an electron acceptor modifying the original electronic and magnetic properties of the

Jose J. Ramasco, Muhittin Mungan

In this paper, we generalize a recently introduced Expectation Maximization (EM) method for graphs and apply it to content-based networks. The EM method provides a classification of the nodes of a graph, and allows to infer relations between the different classes. Content-based networks are ideal models for graphs displaying any kind of community or/and mult

Fernando Revilla

Using the concepts of Hyperbolic Classification of Natural Numbers, Essential Regions and Goldbach Conjecture Function we prove that the existence of a proof of the Goldbach Conjecture in First-Order Arithmetic would imply the existence of another proof in a certain extension that would not be valid in all states of time associated to natural numbers created

Andrea Fortini, Peter G. Bolhuis, Marjolein Dijkstra

We report a numerical study of equilibrium phase-diagrams and interfacial properties of bulk and confined colloid-polymer mixtures using grand canonical Monte Carlo simulations. Colloidal particles are treated as hard spheres, while the polymer chains are described as soft repulsive spheres. The polymer-polymer, colloid-polymer, and wall-polymer interactions

J. Böning, A. Filinov, P. Ludwig, H. Baumgartner

In small confined systems predictions for the melting point strongly depend on the choice of quantity and on the way it is computed, even yielding divergent and ambiguous results. We present a very simple quantity which allows to control these problems -- the variance of the block averaged interparticle distance fluctuations.

David d'Enterria

Exclusive photoproduction of heavy quarkonia in high-energy ultraperipheral ion-ion interactions (gamma A --> V A, where V = J/Psi,Upsilon and the nucleus A remains intact) offers a useful means to constrain the small-x nuclear gluon density. We discuss preliminary results on J/Psi photoproduction in Au-Au collisions at RHIC energies, as well as full simulat

S. Moch, A. Mitov

We consider the factorization properties of on-shell QCD amplitudes with massive partons in the limit when all kinematical invariants are large compared to the parton mass and discuss the structure of their infrared singularities. The dimensionally regulated soft poles and the large collinear logarithms of the parton masses exponentiate to all orders. Based

Inna Aznauryan, Volker Burkert

The helicity amplitudes of the electroexcitation of the Roper resonance on proton are extracted at 1.7 < Q2 < 4.2 GeV2 from recent high precision JLab-CLAS cross sections data and longitudinally polarized beam asymmetry for pi+ electroproduction on protons. The analysis is made using two approaches, dispersion relations and unitary isobar model, which give c

G. Pagliara, J. Schaffner-Bielich

We study the equation state of strongly interacting quark matter within a NJL-like model in which the chiral condensates and the color superconducting gaps are computed self-consistently as a function of the baryon density. A vector interaction term is added to the Lagrangian in order to render the quark matter equation of state stiffer. For the low density

Alice C. Quillen, Nicholas Zufelt, Jaehong Park, Christopher P. O&#39;Dea

We report on an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission. These galaxies are located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that about half of these sources have a sign of excess infrared emission; 22 objects out of 62 are detected at 70 micron

J. Scheibert, A. Prevost, J. Frelat, P. Rey

An original MEMS-based force sensing device is designed which allows to measure spatially resolved normal and tangential stress fields at the base of an elastomeric film. This device is used for the study of the contact stress between a rough film and a smooth glass sphere under normal load. The measured profiles are compared to Finite Elements Method calcul

R. Mehdiyev, A. Siodmok, S. Sultansoy, G. Unel

We evaluate the discovery reach of the ATLAS experiment for down type isosinglet quarks, $D$, using both their neutral and charged decay channels, namely the process $pp\to D\bar{D}+X$ with subsequent decays resulting in $2\ell+2j+E^{miss}_{T}$, $3\ell+2j+E^{miss}_{T}$ and $2\ell+4j$ final states. The integrated luminosity required for observation of a heavy

Ana M. Rubio, G. Alvarez, J. J. Freire

Numerical simulations are performed for isolated cyclic chains with excluded volume. Data are reported for the form factor, S(x), where x is the reduced scattering variable, and also for averages and distributions of the distance between intramolecular units. The averages of distances are compared with two alternative expressions describing their dependence

Luis J. Boya, E. C. G. Sudarshan

We investigate the spin-statistics connection in arbitrary dimensions for hermitian spinor or tensor quantum fields with a rotationally invariant bilinear Lagrangian density. We use essentially the same simple method as for space dimension D = 3. We find the usual connection (tensors as bosons and spinors as fermions) for D = 8n + 3; 8n + 4; 8n + 5, but only

N. Lodieu, N. C. Hambly, R. F. Jameson, S. T. Hodgkin

We present near-infrared (1.15-2.50 microns) medium-resolution (R = 1700) spectroscopy of a sample of 23 brown dwarf candidates in the young Upper Sco association. We confirm membership of 21 brown dwarfs based on their spectral shape, comparison with field dwarfs, and presence of weak gravity-sensitive features. Their spectral types range from M8 to L2 with

Kevin Marshall, Wesley T. Ryle, H. Richard Miller

We present results of a 3 year monitoring campaign of the Seyfert 1 galaxy Markarian 509, using X-ray data from the Rossi X-ray Timing Explorer (RXTE) and optical data taken by the SMARTS consortium. Both light curves show significant variations, and are strongly correlated with the optical flux leading the X-ray flux by 15 days. The X-ray power spectrum sho

Haye Hinrichsen

Ageing phenomena are observed in a large variety of dynamical systems exhibiting a slow relaxation from a non-equilibrium initial state. Ageing can be characterised in terms of the linear response R(t,s) at time t to a local perturbation at time s<t. Usually one distinguishes two dynamical regimes, namely, the quasi-stationary regime, where the response is t

Mark Vogelsberger, Simon D. M. White, Amina Helmi, Volker Springel

We present a new and completely general technique for calculating the fine-grained phase-space structure of dark matter throughout the Galactic halo. Our goal is to understand this structure on the scales relevant for direct and indirect detection experiments. Our method is based on evaluating the geodesic deviation equation along the trajectories of individ

Marion Scheepers

We prove that if X is a separable metric space with the Hurewicz covering property, then the Banach-Mazur game played on X is determined. The implication is not true when &#34;Hurewicz covering property&#34; is replaced with &#34;Menger covering property&#34;.

Roldao da Rocha, Julio M. Hoff da Silva

Dual-helicity eigenspinors of the charge conjugation operator (ELKO spinor fields) belong, together with Majorana spinor fields, to a wider class of spinor fields, the so-called flagpole spinor fields, corresponding to the class (5), according to Lounesto spinor field classification based on the relations and values taken by their associated bilinear covaria

François Demontoux

The wireless networks technologies are becoming more prevalent. As part of our courses, we have to deal with the technical aspects of these technologies. However, the experience of mobile telephony has shown fears that these products can lead to the general public. The latter comes from the use of electromagnetic waves at frequencies close to the frequencies

J. Escrig, D. Altbir, K. Nielsch

The magnetic configurations of bi-phase micro- and nanotubes consisting of a ferromagnetic internal tube, an intermediate non-magnetic spacer, and an external magnetic shell are investigated as a function of their geometry. Based on a continuum approach we obtained analytical expressions for the energy which lead us to obtain phase diagrams giving the relati

K. S. Glavatskiy, D. Bedeaux

In earlier work \cite{bedeaux/vdW/I, bedeaux/vdW/II, bedeaux/vdW/III} a systematic extension of the van der Waals square gradient model to non-equilibrium one-component systems was given. In this work the focus was on heat and mass transfer through the liquid-vapor interface as caused by a temperature difference or an over or under pressure. It was establish

Margarete Knape, Ralph Neininger

We propose and analyze an algorithm to approximate distribution functions and densities of perpetuities. Our algorithm refines an earlier approach based on iterating discretized versions of the fixed point equation that defines the perpetuity. We significantly reduce the complexity of the earlier algorithm. Also one particular perpetuity arising in the analy

Tim A. Koslowski

We use the method of embedding a subsystem (i.e. its observable algebra) into a larger quantum system to extract a cosmological sector from full Loop Quantum Gravity. The application of this method provides a setting for a systematic study of the interplay between diffeomorphism invariance and symmetry reduction. The non-triviality of this relation is shown

Jérôme Rouquette, Julien Haines, Véronique Bornand, Philippe Papet

Piezoelectric PZT solid solutions were studied as a function of pressure and temperature. Moderate pressure is found to induce phase transitions to monoclinic phases (Cm,Cc) for Ti-rich PZT, which are the same ferroelectric phases responsible for the high piezoelectric properties of the MPB. The following transformation sequence P4mm -> Cm -> Cc -> F1 -> F-1

Mathieu Melich, Jacques Dupont-Roc, Philippe Jacquier

The anisotropic effect of a hcp 4He solid matrix on cesium atoms has been proposed as a tool to reveal the parity violating anapole moment of its nucleus. It should also result in splitting the D2 optical excitation line in a way depending on the light polarization. An experimental investigation has been set up using oriented hcp helium crystals in which ces

A. -L. Melchior, F. Combes

We report on the results of an IRAM-30m search for CO emission lines in three galaxies at intermediate redshifts. The idea was to investigate the molecular content of galaxies bright in the infrared at z=0.4-1.5, a redshift desert for molecular line studies, poorly investigated as of yet. We integrated 8-10h per source and did not succeed in detecting any of

T. V. Dudnikova

We consider the Hamiltonian system consisting of a Klein-Gordon vector field and a particle in $\R^3$. The initial date of the system is a random function with a finite mean density of energy which also satisfies a Rosenblatt- or Ibragimov-type mixing condition. Moreover, initial correlation functions are translation-invariant. We study the distribution $μ_t