April 2007 arXiv papers — page 8

J. R. Kirtley, C. Kallin, C. W. Hicks, E. -A. Kim

It is widely believed that the perovskite Sr$_2$RuO$_4$ is an unconventional superconductor with broken time reversal symmetry. It has been predicted that superconductors with broken time reversal symmetry should have spontaneously generated supercurrents at edges and domain walls. We have done careful imaging of the magnetic fields above Sr$_2$RuO$_4$ singl

Nagalakshmi A. Rao, B. A. Kagali

While the usual harmonic oscillator potential gives discrete energies in the non-relativistic case, it does not however give genuine bound states in the relativistic case if the potential is treated in the usual way. In the present article, we have obtained the eigenfunctions of the Dirac oscillator in two spatial dimensions, adapting the prescription of Mos

R. E. de Souza, R. Teixeira

To better understand our Galaxy, we investigate the pertinency of describing the sys tem of nearby disk stars in terms of a two-components Schwarzschild velocity distributio n.Using the proper motion and parallax information of Hipparcos database, we determine t he parameters characterizing the local stellar velocity field of a sample of 22000 disk stars. Th

A. D. Mackey, P. Broby Nielsen

We report on HST/ACS photometry of the rich intermediate-age star cluster NGC 1846 in the Large Magellanic Cloud, which clearly reveals the presence of a double main sequence turn-off in this object. Despite this, the main sequence, sub-giant branch, and red giant branch are all narrow and well-defined, and the red clump is compact. We examine the spatial di

Quoc Le, Alexander Smola

Web page ranking and collaborative filtering require the optimization of sophisticated performance measures. Current Support Vector approaches are unable to optimize them directly and focus on pairwise comparisons instead. We present a new approach which allows direct optimization of the relevant loss functions. This is achieved via structured estimation in

Alexandre Moreau-Gaudry, Anne Prince, Jacques Demongeot, Yohan Payan

Pressure ulcers are recognized as a major health issue in individuals with spinal cord injuries and new approaches to prevent this pathology are necessary. An innovative health strategy is being developed through the use of computer and sensory substitution via the tongue in order to compensate for the sensory loss in the buttock area for individuals with pa

Alexander Konovalov

Let $K$ be field of characteristic 2 and let $G$ be a finite non-abelian 2-group with the cyclic derived subgroup $G'$, and there exists a central element $z$ of order 2 in $Z(G) \backslash G'$. We prove that the unit group of the group algebra $KG$ possesses a section isomorphic to the wreath product of a group of order 2 with the derived subgroup o

Eric Benoit, Laurent Foulloy

This paper deals with sensors which compute and report linguistic assessments of their values.Such sensors, called symbolic sensors are a natural extension of smart ones when working with control systems which use artificial intelligence based technics. After having recalled the smart sensor concepts, this paper introduces the symbolic sensor ones. Links bet

F. Dias, A. I. Dyachenko, V. E. Zakharov

Several theories for weakly damped free-surface flows have been formulated. In this paper we use the linear approximation to the Navier-Stokes equations to derive a new set of equations for potential flow which include dissipation due to viscosity. A viscous correction is added not only to the irrotational pressure (Bernoulli's equation), but also to the

Eric Benoit, Laurent Foulloy

This paper introduces the concept of symbolic sensor as an extension of the smart sensor one. Then, the links between the physical world and the symbolic one are introduced. The creation of symbols is proposed within the frame of the pretopology theory. In order to adapt the sensor to the measurement context, a learning process has been used to provide an ad

Jon Magne Leinaas, Jan Myrheim, Eirik Ovrum

We present a necessary and sufficient condition for a finite dimensional density matrix to be an extreme point of the convex set of density matrices with positive partial transpose with respect to a subsystem. We also give an algorithm for finding such extreme points and illustrate this by some examples.

Goren Gordon, Noam Erez, Gershon Kurizki

In this article we develop, step by step, the framework for universal dynamical control of two-level systems (TLS) or qubits experiencing amplitude- or phase-noise (AN or PN) due to coupling to a thermal bath. A comprehensive arsenal of modulation schemes is introduced and applied to either AN or PN, resulting in completely analogous formulae for the decoher

W. Placzek, K. Golec-Biernat, S. Jadach, M. Skrzypek

We discuss precision Monte Carlo (MC) calculations for solving the QCD evolution equations up to the next-to-leading-order (NLO) level. They employ forward Markovian Monte Carlo algorithms, which provide rigorous solutions of the above equations. These algorithms are implemented in the form of the Monte Carlo program EvolFMC. This program has been cross-chec

Á. sódor

About a dozen field RR Lyrae stars have been observed with the 24-inch Heyde-Zeiss telescope of the Konkoly Observatory at Svábhegy, Budapest, since its refurbishment in 2003. Most of the observing time is allocated for the investigation of the Blazhko modulation, a phenomenon that still does not have a satisfactory explanation. The obtained multicolour CCD

Christian Robenhagen Ravnshoj

This paper provides a probabilistic algorithm to determine generators of the m-torsion subgroup of the Jacobian of a hyperelliptic curve of genus two.

Á. Sódor, B. Szeidl, J. Jurcsik

Context. RR Gem is one of the few Blazhko RR Lyrae that has photometric observations available extended enough to study the long-term courses of its pulsation and modulation properties in detail. Aims. We investigate the pulsation and modulation properties and the relations between them in RR Gem using photometric observations from the past 70 years in order

A. Tanasa, A. Ballesteros, F. J. Herranz

We present a systematic procedure to obtain singular solutions of the constant quantum Yang-Baxter equation in arbitrary dimension. This approach, inspired in the Lie (super)algebra structure, is explicitly applied to the particular case of (graded) contractions of the orthogonal real algebra ${\mathfrak{so}}(N+1)$. In this way we show that "classical&#3

Antonio Pulido Paton, Wei-Tou Ni

ASTROD is a relativity mission concept encompassing multi-purposes. One of its main purposes is to detect gravitational waves sensitive to low-frequency band similar to LISA, but shifted to lower frequencies. In this aspect, ASTROD would complement LISA in probing the Universe and study strong-field black hole physics. Since ASTROD will be after LISA, in the

Nikos Prantzos, Corinne Charbonnel, Christian Iliadis

Hydrogen-burning is the root cause of the star-to-star abundance variations of light nuclei in Galactic globular clusters (GC). In the present work we constrain the physical conditions that gave rise to the observed abundance patterns of Li, C, N, O, Na, Mg, Al, as well as Mg isotopes in the typical case of NGC6752. We perform nucleosynthesis calculations at

Mikito Tanaka, Masashi Chiba, Yutaka Komiyama, Masanori Iye

We have used Suprime-Cam on the Subaru Telescope to conduct a V- and I-band imaging survey of fields sampling the spheroid of the Andromeda galaxy along its south-east minor axis. Our photometric data are deep enough to resolve stars down to the red clump. Based on a large and reliable sample of red giant stars available from this deep wide-field imager, we

Shihoko Ishii

This paper is an introduction to the jet schemes and the arc space of an algebraic variety. We also introduce the Nash problem on arc families.

Dariush Kaviani, Ralf Hofmann

In the effective theory for the deconfining phase of SU(2) Yang-Mills thermodynamics we compute estimates for the moduli of the irreducible three-loop diagrams contributing to the pressure. Our numerical results are in agreement with general expectations.

L. F. Chibotaru, V. H. Dao, A. Ceulemans

In mesoscopic two-gap superconductors with sizes of the order of the coherence length noncomposite vortices are found to be thermodynamically stable in a large domain of the $T - H$ phase diagram. In these phases the vortex cores of one condensate are spatially separated from the other condensate ones, and their respective distributions can adopt distinct sy

B. Basu, P. Bandyopadhyay

We have studied the concurrence of two-site entanglement and have shown that it is related to the geometric phase accumulated due to a complete rotation of the entangled state. The geometric phase and hence the concurrence is evaluated for transverse Ising model and antiferromagnetic chain which is found to be in good agreement with that obtained by other me

Chikara Furusawa, Kunihiko Kaneko

How can a microorganism adapt to a variety of environmental conditions despite there exists a limited number of signal transduction machineries? We show that for any growing cells whose gene expression is under stochastic fluctuations, adaptive cellular state is inevitably selected by noise, even without specific signal transduction network for it. In genera

M. C. Fujiwara, G. Andresen, W. Bertsche, A. Boston

ALPHA is an international project that has recently begun experimentation at CERN's Antiproton Decelerator (AD) facility. The primary goal of ALPHA is stable trapping of cold antihydrogen atoms with the ultimate goal of precise spectroscopic comparisons with hydrogen. We discuss the status of the ALPHA project and the prospects for antihydrogen trapping.

O V Misochko, M V Lebedev, H Schaefer, T Dekorsy

We tailor the shape and phase of the pump pulse spectrum in order to study the coherent lattice dynamics in tellurium. Employing the coherent control via splitting the pump pulse into a two-pulse sequence, we show that the oscillations due to A1 coherent phonons can be cancelled but not enhanced as compared to single pulse excitation. We further demonstrate

D. Andrieux, P. Gaspard

We use a recently proved fluctuation theorem for the currents to develop the response theory of nonequilibrium phenomena. In this framework, expressions for the response coefficients of the currents at arbitrary orders in the thermodynamic forces or affinities are obtained in terms of the fluctuations of the cumulative currents and remarkable relations are o

Titus S. van Erp

The efficiency of path sampling simulations can be improved considerably using the approach of path swapping. For this purpose, we have devised a new algorithmic procedure based on the transition interface sampling technique. In the same spirit of parallel tempering, paths between different ensembles are swapped, but the role of temperature is here played by

Ciro Cattuto, Andrea Baldassarri, Vito D. P. Servedio, Vittorio Loreto

We analyze a large-scale snapshot of del.icio.us and investigate how the number of different tags in the system grows as a function of a suitably defined notion of time. We study the temporal evolution of the global vocabulary size, i.e. the number of distinct tags in the entire system, as well as the evolution of local vocabularies, that is the growth of th

Mayumi Sato, Tomoya Hirota, Mareki Honma, Hideyuki Kobayashi

We report on absolute proper-motion measurements of an H2O maser source in the NGC 281 West molecular cloud, which is located ~320 pc above the Galactic plane and is associated with an HI loop extending from the Galactic plane. We have conducted multi-epoch phase-referencing observations of the maser source with VERA (VLBI Exploration of Radio Astrometry) ov

Jaewoo Lee

Given a finite set of lattice points, we compare its sumsets and lattice points in its dilated convex hulls. Both of these are known to grow as polynomials. Generally, the former are subsets of the latter. In this paper, we will see that sumsets occupy all the central lattice points in convex hulls, giving us a kind of approximation to lattice points in poly

Nicolas Vuillerme, Olivier Chenu, Alexandre Moreau-Gaudry, Jacques Demongeot

The present paper aims at introducing the innovative technologies, based on the concept of "sensory substitution" or "perceptual supplementation", we are developing in the fields of human disability and biomedical engineering. Precisely, our goal is to design, develop and validate practical assistive biomedical and/technical devices and/or re

A. E. Radzhabov, M. K. Volkov, N. G. Kornakov

The branching ratios and photon spectra of the rare processes rho(omega)-> pi^0 pi^0 gamma, rho(omega) -> eta pi^0 gamma are calculated in the framework of the standard local quark Nambu--Jona-Lasinio (NJL) model. Three types of diagrams are considered: the quark box and the pole diagrams with scalar (sigma,a_0(980)) and vector (rho,omega) mesons. The obtain

Jihn E. Kim

It is known that the kinetic mixing of photon and another U(1)_ex gauge boson can introduce millicharged particles. Millicharged particles $f$ of mass 0.1 eV can explain the PVLAS experiment. We suggest a temperature dependent gauge symmetry breaking of U(1)_ex for this idea to be consistent with astrophysical and cosmological constraints.

Alexey A. Kryukov

Quantum mechanics is formulated as a geometric theory on a Hilbert manifold. Images of charts on the manifold are allowed to belong to arbitrary Hilbert spaces of functions including spaces of generalized functions. Tensor equations in this setting, also called functional tensor equations, describe families of functional equations on various Hilbert spaces o

Zhigang Wang, Ping Zhang

Recently, Berry phase in the semiclassical dynamical of Bloch electrons has been found to make a correction to the phase-space density of states and a general multi-band formula for finite-temperature orbital magnetization has been given [Phys. Rev. Lett. \textbf{97}, 026603 (2006)], where the orbital magnetization $\mathcal{M}$ consists of two parts, i.e.,

S Satheesh, E Sandhya

In this note we correct an omission in our paper (Satheesh and Sandhya, 2005) in defining semi-selfdecomposable laws and also show with examples that the marginal distributions of a stationary AR(1) process need not even be infinitely divisible.

Gang Bao, D N A Shaul, H M Araujo, Wei-Tou Ni

ASTROD I is planned as a single spacecraft mission. It will use interferometric and pulse ranging techniques between the spacecraft and ground stations, to make high precision measurements of the parameters that describe the solar system, and to test relativistic gravity with improved accuracy. At the heart of the spacecraft is a test mass, which the spacecr

Eugeny Babichev, Viatcheslav Mukhanov, Alexander Vikman

In this short talk we review our results from the paper hep-th/0604075 with the main stress on the issues of causality and acoustic metric in eikonal approximation. In addition we correct the formula for the redshift of sound signals from our original work. We show that, if there exists a special kind of Born-Infeld type scalar field, then one can send infor

Kohkichi Konno, Munehiro Nishida, Satoshi Tanda, Noriyuki Hatakenaka

Quantum transmissions of a free particle passing through a rectangular potential barrier with dissipation are studied using a path decomposition technique. Dissipative processes strongly suppress the transmission probability at resonance just above the barrier resulting in an unexpected reduction of the mean traversal time through the potential barrier.

Kunihiko Terasaki

By studying the decays D_{s0}^+(2317) --> D_s^+ pi^0 and D_s^{*+} gamma, It is shown that its assignment to the I_3=0 component of iso-triplet scalar four-quark mesons is favored. Productions of its neutral and doubly charged partners are also studied. As the result, it is concluded that they could be observed in B decays. Their iso-singlet partner might hav

J. Campos, A. Lipovka, J. Saucedo

In the present paper the problem of the radiative association of atoms of carbon C with electrons $e^{-}$ for kinetic temperatures $T_{c}$ of $100 < T_{c} < 3000$ K is considered. The calculation of the rate rate constant of the radiative associations is made with principle of detailed balance. It is shown that the rate has correct behavior (it increase with

Monica Guica, Andrew Strominger

These lectures give an introduction to the interrelated topics of Calabi-Yau compactification of the type II string, black hole attractors, the all-orders entropy formula, the dual (0,4) CFT, topological strings and the OSV conjecture. Based on notes by MG of lectures by AS at the 2006 Cargese summer school.

Jonathan E. Grindlay

Active galactic nuclei (AGN) are variable on a wide range of timescales, though relatively few systematic variability surveys have been conducted. Previous broad-band (both spectral and temporal) variability surveys of AGN are limited in their temporal and spectral bandwidth, despite their promise for probing the central engine and black hole mass. We outlin

Zhu Han, H. Vincent Poor

In wireless packet-forwarding networks with selfish nodes, applications of a repeated game can induce the nodes to forward each others&#39; packets, so that the network performance can be improved. However, the nodes on the boundary of such networks cannot benefit from this strategy, as the other nodes do not depend on them. This problem is sometimes known a

Lukasz Fidkowski

We compute the dependence of the tunneling current in a double point contact in the k=3 Read-Rezayi state (which is conjectured to describe an incompressible quantum hall fluid at filling fraction nu=12/5) on voltage, separation between the two contacts, and temperature. Using the tunneling hamiltonian of cond-mat/0607431, we show that the effect of quasihol

A. Stavinskiy, K. Mikhailov, B. Erazmus, R. Lednicky

Residual correlations between decay products due to a combination of both correlations between parents at small relative velocities and small decay momenta are discussed. Residual correlations between photons from pion decays are considered as a new possible source of information on direct photon fraction. Residual correlations in $pγ$ and $pΛ$ systems due t

Boris Gutkin

It is a common assumption that quantum systems with time reversal invariance and classically chaotic dynamics have energy spectra distributed according to GOE-type of statistics. Here we present a class of systems which fail to follow this rule. We show that for convex billiards of constant width with time reversal symmetry and &#34;almost&#34; chaotic dynam

P. P. Kronberg, R. Kothes, C. J. Salter, P. Perillat

We present a deep, 8$\degr$ diameter, 0.4 GHz radio image using a first time combination of the NAIC Arecibo 305-m telescope in Puerto Rico, and the wide-angle interferometer at the Dominion Radio Astrophysical Observatory at Penticton, Canada. Our observations are centered on the Coma Cluster of galaxies in the ``Great Wall&#39;&#39; of galaxies near the No

N. Raj Rao, Alan Edelman

The detection and estimation of signals in noisy, limited data is a problem of interest to many scientific and engineering communities. We present a computationally simple, sample eigenvalue based procedure for estimating the number of high-dimensional signals in white noise when there are relatively few samples. We highlight a fundamental asymptotic limit o

Thomas Fleming

Link homotopy has been an active area of research for knot theorists since its introduction by Milnor in the 1950s. We introduce a new equivalence relation on spatial graphs called component homotopy, which reduces to link homotopy in the classical case. Unlike previous attempts at generalizing link homotopy to spatial graphs, our new relation allows analogu

G. Herring, P. G. Kevrekidis, B. A. Malomed, R. Carretero-Gonzalez

We examine one- and two-dimensional (1D and 2D) models of linearly coupled lattices of the discrete-nonlinear-Schr{ö}dinger type. Analyzing ground states of the systems with equal powers in the two components, we find a symmetry-breaking phenomenon beyond a critical value of the squared $l^2$-norm. Asymmetric states, with unequal powers in their components,

Alexander Friedland, Kathryn M. Zurek, Sergei Bashinsky

In several classes of particle physics models -- ranging from the classical Majoron models, to the more recent scenarios of late neutrino masses or Mass-Varying Neutrinos -- one or more of the neutrinos are postulated to couple to a new light scalar field. As a result of this coupling, neutrinos in the early universe instead of streaming freely could form a

Daniel J. H. Chung, Lisa L. Everett, Konstantin T. Matchev

Kination dominated quintessence models of dark energy have the intriguing feature that the relic abundance of thermal cold dark matter can be significantly enhanced compared to the predictions from standard cosmology. Previous treatments of such models do not include a realistic embedding of inflationary initial conditions. We remedy this situation by constr

A. Neronov, F. Aharonian

Although the giant radiogalaxy M 87 harbors many distinct regions of broad-band nonthermal emission, the recently reported fast variability of TeV gamma rays from M 87 on a timescale of days strongly constrains the range of speculations concerning the possible sites and scenarios of particle acceleration responsible for the observed TeV emission. A natural p

Travis Schedler

We determine the Z-module structure of the preprojective algebra and its zeroth Hochschild homology, for any non-Dynkin quiver (and hence the structure working over any base commutative ring, of any characteristic). This answers (and generalizes) a conjecture of Hesselholt and Rains, producing new $p$-torsion classes in degrees 2p^l, l >= 1, We relate these

Wei Zhang, C. A. R. Sa de Melo

We discuss the time evolution and matter-wave interference of Fermi condensates on the BEC side of Feshbach resonances for s and p-wave superfluids, upon release from harmonic traps. In swave systems, where the order parameter is a complex scalar, we find that the interference patterns depend on the relative phase of the order parameters of the condensates.

J. I. Read, P. Saha, A. V. Maccio

We present non-parametric radial mass profiles for ten QSO strong lensing galaxies. Five of the galaxies have profiles close to $ρ(r)\propto r^{-2}$, while the rest are closer to r^{-1}, consistent with an NFW profile. The former are all relatively isolated early-types and dominated by their stellar light. The latter --though the modeling code did not know t

Bernd-Jochen Schaefer, Jan M. Pawlowski, Jochen Wambach

The relation between the deconfinement and chiral phase transition is explored in the framework of an Polyakov-loop-extended two-flavor quark-meson (PQM) model. In this model the Polyakov loop dynamics is represented by a background temporal gauge field which also couples to the quarks. As a novelty an explicit quark chemical potential and N_f-dependence in

Marco Frasca

We give a comparison of the spectrum of Yang-Mills theory in $D=3+1$, recently derived with a strong coupling expansion, with lattice data. We verify excellent agreement also for 2$^{++}$ glueball. A deep analogy with the $D=2+1$ case is obtained and a full quantum theory of this approach is also given.

C. Kaufhold, F. R. Klinkhamer

A detailed analysis of vacuum Cherenkov radiation in spacelike Maxwell-Chern-Simons (MCS) theory is presented. A semiclassical treatment reproduces the leading terms of the tree-level result from quantum field theory. Moreover, certain quantum corrections turn out to be suppressed for large energies of the charged particle, for example, the quantum correctio

Rina Kanamoto, Lincoln D. Carr, Masahito Ueda

Topological winding and unwinding in a quasi-one-dimensional metastable Bose-Einstein condensate are shown to be manipulated by changing the strength of interaction or the frequency of rotation. Exact diagonalization analysis reveals that quasidegenerate states emerge spontaneously near the transition point, allowing a smooth crossover between topologically

Christopher D. Carone, Joshua Erlich, Marc Sher

We observe several interesting phenomena in a technicolor-like model of electroweak symmetry breaking based on the D4-D8-D8bar system of Sakai and Sugimoto. The benefit of holographic models based on D-brane configurations is that both sides of the holographic duality are well understood. We find that the lightest technicolor resonances contribute negatively

Dmitri Diakonov, Victor Petrov

We construct the integration measure over the moduli space of an arbitrary number of N kinds of dyons of the pure SU(N) gauge theory at finite temperatures. The ensemble of dyons governed by the measure is mathematically described by a (supersymmetric) quantum field theory that is exactly solvable and is remarkable for a number of striking features: 1) The f

Yi Zhao, Chi-Hang Fred Fung, Bing Qi, Christine Chen

Quantum key distribution (QKD) systems can send signals over more than 100 km standard optical fiber and are widely believed to be secure. Here, we show experimentally for the first time a technologically feasible attack, namely the time-shift attack, against a commercial QKD system. Our result shows that, contrary to popular belief, an eavesdropper, Eve, ha

Vincent Bouchard, Ron Donagi

We obtain a detailed classification for a class of non-simply connected Calabi-Yau threefolds which are of potential interest for a wide range of problems in string phenomenology. These threefolds arise as quotients of Schoen&#39;s Calabi-Yau threefolds, which are fiber products over P1 of two rational elliptic surfaces. The quotient is by a freely acting fi

D. J. Ampleford, S. V. Lebedev, A. Ciardi, S. N. Bland

The first laboratory astrophysics experiments to produce a radiatively cooled plasma jet with dynamically significant angular momentum are discussed. A new configuration of wire array z-pinch, the twisted conical wire array, is used to produce convergent plasma flows each rotating about the central axis. Collision of the flows produces a standing shock and j

Radu Laza

We describe the GIT compactification of the moduli space of cubic fourfolds, with a special emphasis on the role played by singularities. Our main result is that a cubic fourfold with only isolated simple (A-D-E) singularities is GIT stable. Conversely, with some minor exceptions, the stability for cubic fourfolds is characterized by this condition.

Marcos M. Alexandrino, Dirk Toeben

A singular foliation on a complete riemannian manifold M is said to be riemannian if each geodesic that is perpendicular at one point to a leaf remains perpendicular to every leaf it meets. We prove that the regular leaves are equifocal, i.e., the end point map of a normal foliated vector field has constant rank. This implies that we can reconstruct the sing

Ph. Blanchard, R. Figari, A. Mantile

Making use of recent techniques in the theory of selfadjoint extensions of symmetric operators, we characterize the class of point interaction Hamiltonians in a 3-D bounded domain with regular boundary. In the particular case of one point interaction acting in the center of a ball, we obtain an explicit representation of the point spectrum of the operator to

Jaume Gomis, Takuya Okuda

We prove that the open topological string partition function on a D-brane configuration in a Calabi-Yau manifold X takes the form of a closed topological string partition function on a different Calabi-Yau manifold X_b. This identification shows that the physics of D-branes in an arbitrary background X of topological string theory can be described either by

X. Guan, O. Zatsarinny, K. Bartschat, B. I. Schneider

A general {\it ab-initio} and non-perturbative method to solve the time-dependent Schrödinger equation (TDSE) for the interaction of a strong attosecond laser pulse with a general atom, i.e., beyond the models of quasi-one-electron or quasi-two-electron targets, is described. The field-free Hamiltonian and the dipole matrices are generated using a flexible $

V. E. S. Szabo

In 1954 it was proved if f is infinitely differentiable in the interval I and some derivative (of order depending on x) vanishes at each x, then f is a polynomial. Later it was generalized for multi-variable case. In this paper we give an extension for distributions.

Thomas Silverston, Olivier Fourmaux, Kave Salamatian

P2P IPTV applications arise on the Internet and will be massively used in the future. It is expected that P2P IPTV will contribute to increase the overall Internet traffic. In this context, it is important to measure the impact of P2P IPTV on the networks and to characterize this traffic. Dur- ing the 2006 FIFA World Cup, we performed an extensive measuremen

Axel Arnold, Suckjoon Jun

We report molecular dynamics simulations of the segregation of two overlapping chains in cylindrical confinement. We find that the entropic repulsion between the chains can be sufficiently strong to cause segregation on a time scale that is short compared to the one for diffusion. This result implies that entropic driving forces are sufficiently strong to ca

Yves van Gennip, Mark A. Peletier

We study a variational model for a diblock-copolymer/homopolymer blend. The energy functional is a sharp-interface limit of a generalisation of the Ohta-Kawasaki energy. In one dimension, on the real line and on the torus, we prove existence of minimisers of this functional and we describe in complete detail the structure and energy of stationary points. Fur

Ignacio Negueruela, David M. Smith, Jose Miguel Torrejon, Pablo Reig

INTEGRAL monitoring of the Galactic Plane is revealing a growing number of recurrent X-ray transients, characterised by short outbursts with very fast rise times (~ tens of minutes) and typical durations of a few hours. A substantial fraction of these sources are associated with OB supergiants and hence define a new class of massive X-ray binaries, which we

Benedikt Obermayer, Oskar Hallatschek

The time-dependent transverse response of stiff polymers, represented as weakly-bending wormlike chains (WLCs), is well-understood on the linear level, where transverse degrees of freedom evolve independently from the longitudinal ones. We show that, beyond a characteristic time scale, the nonlinear coupling of transverse and longitudinal motion in an inexte

P. A. Horvathy

Various aspects including the construction and the symmetries of Abelian Chern-Simons vortices are reviewed. Extended version of the Lectures delivered at NIKHEF (Amsterdam), July 2006. Typos corrected, some refernces added.

C. Krellner, S. Haas, C. Goldmann, K. P. Pernstich

The density of trap states in the bandgap of semiconducting organic single crystals has been measured quantitatively and with high energy resolution by means of the experimental method of temperature-dependent space-charge-limited-current spectroscopy (TD-SCLC). This spectroscopy has been applied to study bulk rubrene single crystals, which are shown by this

R. J. Heary, J. E. Han, Lingyin Zhu

We show that a strongly correlated quantum dot embedded in an Aharonov-Bohm interferometer can be used to filter both charge and spin at zero voltage bias. The magnitude with which the Aharonov-Bohm arm is coupled to the system controls the many-body effects on the quantum dot. When the quantum dot is in the Kondo regime the flow of charge through the system

Günter Rottenfußer, Johannes Rückert, Lasse Rempe, Dierk Schleicher

We construct an entire function in the Eremenko-Lyubich class $\B$ whose Julia set has only bounded path-components. This answers a question of Eremenko from 1989 in the negative. On the other hand, we show that for many functions in $\B$, in particular those of finite order, every escaping point can be connected to $\infty$ by a curve of escaping points. Th

V. V. Abaev, P. Metsä, M. E. Sainio

The Goldberger-Miyazawa-Oehme sum rule is used to extract the pion-nucleon coupling constant from experimental $π$N information. Chiral perturbation theory is exploited in relating the pionic hydrogen s-wave level shift and width results to the appropriate scattering lengths. The deduced value for the coupling is $f^2 = 0.075 \pm 0.002$, where the largest so

M. A. Thompson, S. Serjeant, T. Jenness, D. Scott

The sub-millimetre wavelength regime is perhaps the most poorly explored over large areas of the sky, despite the considerable effort that has been expended in making deep maps over small regions. As a consequence the properties of the sub-millimetre sky as a whole, and of rare bright objects in particular, remains largely unknown. Here we describe a forthco

Naoyuki Kawahara, Jun Nishimura, Shingo Takeuchi

We study thermodynamical properties of a fuzzy sphere in matrix quantum mechanics of the BFSS type including the Chern-Simons term. Various quantities are calculated to all orders in perturbation theory exploiting the one-loop saturation of the effective action in the large-N limit. The fuzzy sphere becomes unstable at sufficiently strong coupling, and the c

J. E. Han, R. J. Heary

We extend the imaginary-time formulation of the equilibrium quantum many-body theory to steady-state nonequilibrium with an application to strongly correlated transport. By introducing Matsubara voltage, we keep the finite chemical potential shifts in the Fermi-Dirac function, in agreement with the Keldysh formulation. The formulation is applied to strongly

Amaury Lambert

Splitting trees are those random trees where individuals give birth at constant rate during a lifetime with general distribution, to i.i.d. copies of themselves. The width process of a splitting tree is then a binary, homogeneous Crump--Mode--Jagers (CMJ) process, and is not Markovian unless the lifetime distribution is exponential. Here, we allow the birth

Benoit Fresse

In the theory of operads we consider functors of generalized symmetric powers defined by sums of coinvariant modules under actions of symmetric groups. One observes classically that the construction of symmetric functors provides an isomorphism from the category of symmetric modules to a subcategory of the category of functors on the base category. The purpo

V. P. Spiridonov

This is a brief overview of the status of the theory of elliptic hypergeometric functions to the end of 2012 written as a complementary chapter to the Russian edition of the book by G.E. Andrews, R. Askey, and R. Roy, Special Functions, Encycl. of Math. Appl. 71, Cambridge Univ. Press, 1999.

K. Biazzo, L. Pasquini, L. Girardi, A. Frasca

We test our capability of deriving stellar physical parameters of giant stars by analysing a sample of field stars and the well studied open cluster IC 4651 with different spectroscopic methods. The use of a technique based on line-depth ratios (LDRs) allows us to determine with high precision the effective temperature of the stars and to compare the results

Alexander Burinskii

The charged and spinning lightlike solutions are obtained in the Kerr-Schild formalism. In particular, one of them may be considered as an ultrarelativistic boost of the Kerr-Newman solution along the direction of angular momentum. The Kerr singular ring disappears, however, there remains a finite parameter $a$ which determines spin by the Kerr relation $J=m

Rahul Basu, Eric Laenen, Anuradha Misra, Patrick Motylinski

We extend next-to-leading logarithmic threshold and joint resummation for prompt photon production to include leading collinear effects. The impact of these effects is assessed for both fixed-target and collider kinematics. We find them in general to be small, but noticeable.

Andreas Enge

We analyse and compare the complexity of several algorithms for computing modular polynomials. We show that an algorithm relying on floating point evaluation of modular functions and on interpolation, which has received little attention in the literature, has a complexity that is essentially (up to logarithmic factors) linear in the size of the computed poly

S. V. Fallert, Y. M. Kim, C. J. Neugebauer, S. N. Taraskin

The critical behavior of the contact process in disordered and periodic binary 2d-lattices is investigated numerically by means of Monte Carlo simulations as well as via an analytical approximation and standard mean field theory. Phase-separation lines calculated numerically are found to agree well with analytical predictions around the homogeneous point. Fo

Kunio Obitsu, Scott A. Wolpert

The family hyperbolic metric for the plumbing variety $\{zw=t\}$ and the non holomorphic Eisenstein series $E(ζ;2)$ are combined to provide an explicit expansion for the hyperbolic metrics for degenerating families of Riemann surfaces. Applications include an asymptotic expansion for the Weil-Petersson metric and a local form of symplectic reduction.

Davoud Kamani

We study behaviors of a compact dimension and the $T$-duality, in the presence of the wrapped closed bosonic strings. When the closed strings interact and form another system of strings, the radius of compactification increases. This modifies the $T$-duality, which we call it as $T$-duality-like. Some effects of the $T$-duality-like will be studied.

R. Rezaei, R. Schlichenmaier, W. Schmidt, O. Steiner

We study the structure of the photospheric magnetic field of the quiet Sun by investigating weak spectro-polarimetric signals. We took a sequence of Stokes spectra of the Fe I 630.15 nm and 630.25 nm lines in a region of quiet Sun near the disk center, using the POLIS spectro-polarimeter at the German VTT on Tenerife. The line cores of these two lines form a

Aik Hui Chan, Harald Fritzsch, Shu Luo, Zhi-zhong Xing

Current experimental data allow the zero value for one neutrino mass, either m_1 = 0 or m_3 = 0. This observation implies that a realistic neutrino mass texture can be established by starting from the limit (a) m_1 = m_2 = 0 and m_3 \neq 0 or (b) m_1 = m_2 \neq 0 and m_3 = 0. In both cases, we may introduce a particular perturbation which ensures the resulta

F. Briscese, A. Marciano

We develop here a mechanism that, without making use of a cosmological constant, reproduces an accelerating universe. This is done by taking into account Casimir vacuum energy density, assuming that the underlying theory allows a maximum momentum, that turns out to be the leading contribution term to Einstein equations in a large expanding FRW universe. As s