June 2008 arXiv papers — page 8

Kostas Kleidis, Apostolos Kuiroukidis, Demetrios B Papadopoulos, Loukas Vlahos

Gravitational instabilities in a magnetized Friedman - Robertson - Walker (FRW) Universe, in which the magnetic field was assumed to be too weak to destroy the isotropy of the model, are known and have been studied in the past. Accordingly, it became evident that the external magnetic field disfavors the perturbations' growth, suppressing the correspondi

Irina I. Bodrenko

The complete local classification and geometric description of n-dimensional submanifolds F with recurrent nonparallel second fundamental form in the spaces of constant curvature M(c) are obtained in this article.

A. A. Shanenko, M. D. Croitoru, F. M. Peeters

In high-quality nanowires, quantum confinement of the transverse electron motion splits the band of single-electron states in a series of subbands. This changes in a qualitative way the scenario of the magnetic-field induced superconductor-to-normal transition. We numerically solve the Bogoliubov-de Gennes equations for a clean metallic cylindrical nanowire

E. Cancès, F. Legoll, M. -C. Marinica, K. Minoukadeh

The Activation-Relaxation Technique nouveau (ARTn) is an eigenvector following method for systematic search of saddle points and transition pathways on a given potential energy surface. We propose a variation of this method aiming at improving the efficiency of the local convergence close to the saddle point. We prove the convergence and robustness of this n

Guillermo Torres, Joshua N. Winn, Matthew J. Holman

With 40 or more transiting exoplanets now known, the time is ripe to seek patterns and correlations among their observed properties, which may give important insights into planet formation, structure, and evolution. This task is made difficult by the widely different methodologies that have been applied to measure their properties in individual cases. Furthe

J. C. Ndogmo

We apply a novel method for the equivalence group and its infinitesimal generators to the investigation of invariants of linear ordinary differential equations. First, a comparative study of this method is illustrated by an example. Next, the method is used to obtain the invariants of low order linear ordinary differential equations, and the structure invari

F. R. Klinkhamer, M. Risse

Nonbirefringent modified-Maxwell theory, coupled to standard Dirac particles, involves nine dimensionless parameters, which can be bounded by the inferred absence of vacuum Cherenkov radiation for ultrahigh-energy cosmic rays (UHECRs). With selected UHECR events, two-sided bounds on the eight nonisotropic parameters are obtained at the 10^{-18} level, togeth

Jurgen Baacke, Nina Kevlishvili

We present an exact numerical computation of the one-loop correction of the string tension for the Nielsen-Olesen vortex in the Abelian Higgs model. The computations proceeds via the computation of the Euclidean Green's function for the gauge, Higgs and Faddeev-Popov fields using mode functions, and taking the appropriate trace. Renormalization is an ess

E. B. Ramayya, D. Vasileska, S. M. Goodnick, I. Knezevic

The low-field electron mobility in rectangular silicon nanowire (SiNW) transistors was computed using a self-consistent Poisson-Schrödinger-Monte Carlo solver. The behavior of the phonon-limited and surface-roughness-limited components of the mobility was investigated by decreasing the wire width from 30 nm to 8 nm, the width range capturing a crossover betw

Kristoffer Arnsfelt Hansen, Thomas Dueholm Hansen, Peter Bro Miltersen, Troels Bjerre Sørensen

We consider approximating the minmax value of a multi-player game in strategic form. Tightening recent bounds by Borgs et al., we observe that approximating the value with a precision of epsilon log n digits (for any constant epsilon>0 is NP-hard, where n is the size of the game. On the other hand, approximating the value with a precision of c log log n digi

G. J. Meyer, N. L. Dias, R. H. Blick, I. Knezevic

We investigate the relationship between electronics and geometry in a nonplanar SiGe/Si resonant quantum cavity (RQC) subject to a magnetic field. The transfer matrix technique originally due to Usuki and coworkers (Phys. Rev. B 52, 8244 1995) has been modified to account for the nonzero local curvature of the RQC. Our results demonstrate that low-temperatur

M. Cantiello, N. Langer

Thermohaline mixing has recently been proposed to occur in low mass red giants, with large consequences for the chemical yields of low mass stars. We investigate the role of thermohaline mixing during the evolution of stars between 1Msun and 3Msun, in comparison to other mixing processes acting in these stars. We confirm that thermohaline mixing has the pote

Vladimir V. V'yugin

The remarkable results of Foster and Vohra was a starting point for a series of papers which show that any sequence of outcomes can be learned (with no prior knowledge) using some universal randomized forecasting algorithm and forecast-dependent checking rules. We show that for the class of all computationally efficient outcome-forecast-based checking rules,

Guy Joulin, Bruno Denet

Sivashinsky's (1977) nonlinear integro-differential equation for the shape of corrugated 1-dimensional flames is ultimately reducible to a 2N-body problem, involving the 2N complex poles of the flame slope. Thual, Frisch & Henon (1985) derived singular linear integral equations for the pole density in the limit of large steady wrinkles $(N \gg 1)$, which

J. Goold, D. O Donoghue, Th. Busch

We investigate low-density, quantum-degenerate gases in the presence of a localised attractive potential in the centre of a one-dimensional harmonic trap.The attractive potential is modelled using a parameterised delta-function, allowing us to determine all single particle eigenfunctions analytically. From these we calculate the ground state many-body proper

Dorothea Samtleben

The footprint of inflation in the polarization pattern of the CMB is expected at more than an order of magnitude below the limits of current polarization measurements. Large receiver arrays are mandatory for achieving the required sensitivity. We describe here the approach of the Q/U Imaging ExperimenT (QUIET) which will use coherent detector arrays. Pseudo-

Benjamin Cross, Laurent Puech, Pierre-Etienne Wolf

We describe a set-up for studying adsorption of helium in silica aerogels, where the adsorbed amount is easily and precisely controlled by varying the temperature of a gas reservoir between 80 K and 180 K. We present validation experiments and a first application to aerogels. This device is well adapted to study hysteresis, relaxation, and metastable states

D. R. Heath-Brown

Let k>2 be a fixed integer exponent and let θ> 9/10. We show that a positive integer N can be represented as a non-trivial sum or difference of 3 k-th powers, using integers of size at most B, in O(B^θN^{1/10}) ways, providing that N << B^{3/13}. The significance of this is that we may take θstrictly less than 1. We also prove the estimate O(B^{10/k}), (subj

Jonathan Bennett, Neal Bez, Anthony Carbery

It is known that if $q$ is an even integer then the $L^q(\mathbb{R}^d)$ norm of the Fourier transform of a superposition of translates of a fixed gaussian is monotone increasing as their centres &#34;simultaneously slide&#34; to the origin. We provide explicit examples to show that this monotonicity property fails dramatically if $q > 2$ is not an even integ

N. Ni, S. Nandi, A. Kreyssig, A. I. Goldman

CaFe$_2$As$_2$ has been synthesized and found to form in the tetragonal, ThCr$_2$Si$_2$ structure with lattice parameters $a = 3.912(68) Å$ and $c = 11.667(45) Å$. Upon cooling through 170 K, CaFe$_2$As$_2$ undergoes a first order, structural phase transition to a low temperature, orthorhombic phase with a $2 - 3$ K range of hysteresis and coexistence. This

D. J. Papoular

We consider a classical, two-dimensional system of identical particles which interact via a finite-ranged, repulsive pair potential. We assume that the system is in a crystalline phase. We calculate the normal vibrational modes of a two-dimensional square Bravais lattice, first analytically within the nearest-neighbour approximation, and then numerically, re

A. L. Alexander, R. Lauro, A. Louchet, T. Chanelière

We report on the experimental demonstration of stimulated Raman adiabatic passage (STIRAP) in a Tm$^{3+}$:YAG crystal. Tm$^{3+}$:YAG is a promising material for use in quantum information processing applications, but as yet there are few experimental investigations of coherent Raman processes in this material. We investigate the effect of inhomogeneous broad

E. B. Ramayya, D. Vasileska, S. M. Goodnick, I. Knezevic

We investigate the effects of electron and acoustic-phonon confinement on the low-field electron mobility of thin square silicon nanowires (SiNWs) that are surrounded by SiO$_2$ and gated. We employ a self-consistent Poisson-Schrödinger-Monte Carlo solver that accounts for scattering due to acoustic phonons (confined and bulk), intervalley phonons, and the S

Manuel Kauers, Doron Zeilberger

The great enumerator Germain Kreweras empirically discovered this intriguing fact, and then needed lots of pages[K], and lots of human ingenuity, to prove it. Other great enumerators, for example, Heinrich Niederhausen[N], Ira Gessel[G1], and Mireille Bousquet-Mélou[B], found other ingenious, ``simpler&#39;&#39; proofs. Yet none of them is as simple as ours!

E. M. Berkhuijsen, A. Fletcher

In a search for the signature of turbulence in the diffuse interstellar medium in gas density distributions, we determined the probability distribution functions (PDFs) of the average volume densities of the diffuse gas. The densities were derived from dispersion measures and HI column densities towards pulsars and stars at known distances. The PDFs of the a

Wolfgang Hasse, Volker Perlick

We discuss the geometry of timelike surfaces (two-dimensional submanifolds) in a Lorentzian manifold and its interpretation in terms of general relativity. A classification of such surfaces is presented which distinguishes four cases of special algebraic properties of the second fundamental form from the generic case. In the physical interpretation a timelik

Daniel C. Fabrycky

So far radial velocity (RV) measurements have discovered ~25 stars to host multiple planets. The statistics imply that many of the known hosts of transiting planets should have additional planets, yet none have been solidly detected. They will be soon, via complementary search methods of RV, transit-time variations (TTV) of the known planet, and transits of

Valerio Ramos-Batista, Kelly Lubeck

We present a new family of embedded doubly periodic minimal surfaces, of which the symmetry group does not coincide with any other example known before.

Clare Dobbs, Simon Glover, Paul Clark, Ralf Klessen

We investigate the thermodynamics of the ISM and the formation of molecular hydrogen through numerical simulations of spiral galaxies. The model follows the chemical, thermal and dynamical response of the disc to an external spiral potential. Self-gravity and magnetic fields are not included. The calculations demonstrate that gas can cool rapidly when subjec

M. V. Fistul, V. M. Vinokur, T. I. Baturina

We investigate theoretically transport properties of one- and two-dimensional regular Josephson junction arrays (JJAs) in an insulating state. We derive the low-temperature current-voltage characteristics for the current mediated by the Cooper pair transfer across the system. In the case where the screening length associated with the capacitance of the islan

N. Syassen, D. M. Bauer, M. Lettner, T. Volz

Atomic quantum gases in the strong-correlation regime offer unique possibilities to explore a variety of many-body quantum phenomena. Reaching this regime has usually required both strong elastic and weak inelastic interactions, as the latter produce losses. We show that strong inelastic collisions can actually inhibit particle losses and drive a system into

Takahiro Ashihara, Masahiko Miyamoto

If a vertex operator algebra $V=\oplus_{n=0}^{\infty}V_n$ satisfies $\dim V_0=1, V_1=0$, then $V_2$ has a commutative (nonassociative) algebra structure called Griess algebra. One of the typical examples of commutative (nonassociative) algebras is a Jordan algebra. For example, the set $Sym_d(\C)$ of symmetric matrices of degree $d$ becomes a Jordan algebra.

Christian Bogner, Stefan Weinzierl

In this talk we discuss sector decomposition. This is a method to disentangle overlapping singularities through a sequence of blow-ups. We report on an open-source implementation of this algorithm to compute numerically the Laurent expansion of divergent multi-loop integrals. We also show how this method can be used to prove a theorem which relates the coeff

A. Tartari, M. Zannoni, M. Gervasi, G. Boella

We present values of temperature and spectral index of the galactic diffuse radiation measured at 600 and 820 MHz along a 24 hours right ascension circle at declination $δ= +42^{\circ}$. They have been obtained from a subset of absolute measurements of the sky temperature made with TRIS, an experiment devoted to the measurement of the Cosmic Microwave Backgr

G. Baur

Ultraperipheral collisions at collider energies are a useful tool to study photon-hadron (proton/nucleus) and photon-photon interactions in a hitherto unexplored energy regime. Theoretical tools to study these processes are briefly described. Some current results and problems are discussed

Xavier Calmet, Marco Feliciangeli

In this note we derive a bound using data from cosmic rays physics on a model recently proposed to solve the hierarchy problem by lowering the Planck scale to the TeV region without the introduction of extra-dimensions. We show that the non observation of small black holes by AGASA implies a model independent limit for the four-dimensional reduced Planck mas

L. Delfini, S. Lepri, R. Livi, A. Politi

We provide an explicit representation of the nonequilibrium invariant measure for a chain of harmonic oscillators with conservative noise in the presence of stationary heat flow. By first determining the covariance matrix, we are able to express the measure as the product of Gaussian distributions aligned along some collective modes that are spatially locali

The Pierre Auger Collaboration

The energy spectrum of cosmic rays above 2.5x10^18eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the flux, J ~ E^-gamma, at energies between 4x10^18eV and 4x10^19eV is 2.69+-0.02(stat)+-0.06(syst), steepening to 4.2+-0.4(stat)+-0.06(syst) at higher energies, consistent with the prediction by

Manuel Kauers, Christoph Koutschan, Doron Zeilberger

We present a computer-aided, yet fully rigorous, proof of Ira Gessel&#39;s tantalizingly simply-stated conjecture that the number of ways of walking $2n$ steps in the region $x+y \geq 0, y \geq 0$ of the square-lattice with unit steps in the east, west, north, and south directions, that start and end at the origin, equals $16^n\frac{(5/6)_n(1/2)_n}{(5/3)_n(2

N. Balakrishnan, Edsel A. Peña, Mervyn J. Silvapulle

Pranab K. Sen has contributed extensively to many areas of Statistics including order statistics, nonparametrics, robust inference, sequential methods, asymptotics, biostatistics, clinical trials, bioenvironmental studies and bioinformatics. His long list of over 600 publications and 22 books and volumes along with numerous citations during the past 5 decade

Boris D. Kudryashov, Anton V. Porov, Eunmi L. Oh

This paper is concerned with scalar quantization of transform coefficients in an audio codec. The generalized Gaussian distribution (GGD) is used as an approximation of one-dimensional probability density function for transform coefficients obtained by modulated lapped transform (MLT) or modified cosine transform (MDCT) filterbank. The rationale of the model

Abhishek Agarwal

Mass deformations of supersymmetric Yang-Mills theories in three spacetime dimensions are considered. The gluons of the theories are made massive by the inclusion of a non-local gauge and Poincare invariant mass term due to Alexanian and Nair, while the matter fields are given standard Gaussian mass-terms. It is shown that the dimensional reduction of such m

E. Klempt

The mass spectrum of Delta resonances is compared to predictions based on three quark-model variants, to predictions assuming that chiral symmetry is restored in high-mass baryon resonances, and to predictions derived from AdS/QCD. The latter approach yields a nearly perfect agreement when the confinement property of QCD is modeled by a soft wall in AdS.

Mohcine Chraibi, Armin Seyfried

The social-force model is systematically modified to achieve a satisfying agreement with the fundamental diagram. Furthermore, our modification allows an efficient computation of the simulation. Finally, different simulation-results will be compared to empirical data.

Stanislav Maslovski, Pekka Alitalo, Sergei Tretyakov

A new principle of subwavelength imaging based on frequency scanning is considered. It is shown that it is possible to reconstruct the spatial profile of an external field exciting an array (or coupled arrays) of subwavelength-sized resonant particles with a frequency scan over the whole band of resonating array modes. During the scan it is enough to measure

M. D. Arnold, A. V. Khokhlov

We consider Cauchy problem for Fourier transformation of 3-dimensional Navier-Stokes system with zero external force. Using initial data purposed by Dong Li and Ya.G.Sinai we implement self-similar regime producing fast growing behavior of the energy of solution while time tends to critical value.

Guillermo A. Gonzalez, Antonio C. Gutierrez-Pineres, Paolo A. Ospina

An infinite family of axisymmetric charged dust disks of finite extension is presented. The disks are obtained by solving the vacuum Einstein-Maxwell equations for conformastatic spacetimes, which are characterized by only one metric function. In order to obtain the solutions, it is assumed that the metric function and the electric potential are functionally

Henry De Thelin, Gabriel Vigny

We study the dynamics of meromorphic maps for a compact Kaehler manifold X. More precisely, we give a simple criterion that allows us to produce a measure of maximal entropy. We can apply this result to bound the Lyapunov exponents. Then, we study the particular case of a family of generic birational maps of P^k for which we construct the Green currents and

M. B. Hastings, L. S. Levitov

We introduce an approach to describe quantum-coherent evolution of a system of cold atoms in an optical lattice triggered by a change in superlattice potential. Using a time-dependent mean field description, we map the problem to a strong coupling limit of previously studied time-dependent BCS model. We compare the mean field dynamics to a simulation using l

Javier Ramos-Caro, Framsol Lopez-Suspes, Guillermo A. Gonzalez

Regular and chaotic test particle motion in gravitational fields due to stellar bodies with quadrupolar and octupolar deformation are studied using Poincare surfaces of section. In first instance, we analyze the purely Newtonian case and we find that the octupolar term induces a distortion in the KAM curves corresponding to regular trajectories as well as an

Javier Ramos-Caro, Guillermo A. Gonzalez

We present two formulations of Fokker-Planck-Rosenbluth-type (FPR) equations for many-particle self-gravitating systems, with first order relativistic corrections in the post-Newtonian approach (1PN). The first starts from a covariant Fokker-Planck equation for a simple gas, introduced recently by G. Chacon-Acosta and G. Kremer (Phys. Rev. E 76, 021201, 2007

G. Wu, H. Chen, T. Wu, Y. L. Xie

We report that intrinsic transport and magnetic properties, and their anisotropy from high quality single crystal $CaFe_2As_2$. The resistivity anisotropy ($ρ_c/ρ_{ab}$) is $\sim 50 $, and less than 150 of $BaFe_2As_2$, which arises from the strong coupling along c-axis due to an apparent contraction of about 0.13 nm compared to $BaFe_2As_2$. Temperature ind

Silvia Faggian, Fausto Gozzi

We develop the dynamic programming approach for a family of infinite horizon boundary control problems with linear state equation and convex cost. We prove that the value function of the problem is the unique regular solution of the associated stationary Hamilton--Jacobi--Bellman equation and use this to prove existence and uniqueness of feedback controls. T

Juan F. Pedraza, Javier Ramos-Caro, Guillermo A. Gonzalez

We present the formulation of a new infinite family of self-consistent stellar models, designed to describe axisymmetric flat galaxies. The corresponding density-potential pair is obtained as a superposition of members belonging to the generalized Kalnajs family, by imposing the condition that the density can be expressed as a regular function of the gravita

Asish K. Kundu, R. Ranjith, V. Pralong, N. Nguyen

ABO3 perovskite multiferroic La0.5Bi0.5Mn0.5Fe0.5O3.09 where the B-site cations is responsible for the magnetic properties and the A-site cation with lone pair electron is responsible for the ferroelectric properties was synthesized at normal conditions. This oxide exhibits a ferromagnetic transition around 240 K with a well defined hysteresis loop, and a si

Javier Ramos-Caro, Framsol Lopez-Suspes, Guillermo A. Gonzalez

The motion of test particles in the gravitational fields generated by the first four members of the infinite family of generalized Kalnajs discs, is studied. In first instance, we analyze the stability of circular orbits under radial and vertical perturbations and describe the behavior of general equatorial orbits and so we find that radial stability and ver

Adel Khalfallah, Siegmund Kosarew

We apply methods of nonstandard mathematics in order to regard analytic geometry in a very different way. For example, complex spaces are seen to be the &#34;standard part&#34; of certain algebraic nonstandard schemes. We construct a category of such schemes, sitting in between usual algebraic schemes (over the complex numbers) and that of complex spaces. We

Atish Kamble, Kuntal Misra, D. Bhattacharya, Ram Sagar

The afterglow of GRB 050401 presents several novel and interesting features : [1] An initially faster decay in optical band than in X-rays. [2] A break in the X-ray light curve after $\sim$ 0.06 day with an unusual slope after the break. [3] The X-ray afterglow does not show any spectral evolution across the break while the R band light curve does not show a

A. A. Hakobyan, A. R. Petrosian, B. McLean, D. Kunth

It is widely accepted that the progenitors of core collapse SNe are young massive stars and therefore their host galaxies are mostly spiral or irregular galaxies dominated by a young stellar population. Surprisingly, among morphologically classified hosts of core collapse SNe, we find 22 cases where the host has been classified as an Elliptical or S0 galaxy.

Alexei Grinbaum

We start by remarks on the scientific and societal context of today&#39;s theoretical physics. Major classes of models for physics to be explored at the LHC are then reviewed. This leads us to propose an LHC timeline and a list of potential effects on theoretical physics and the society. We then explore three conceptual questions connected with the LHC physi

Guillermo A. Gonzalez, Jerson I. Reina

An infinite family of axially symmetric thin disks of finite radius is presented. The family of disks is obtained by means of a method developed by Hunter and contains, as its first member, the Kalnajs disk. The surface densities of the disks present a maximum at the center of the disk and then decrease smoothly to zero at the edge, in such a way that the ma

Adil Belhaj, Luis J. Boya, Antonio Segui

We consider manifolds with special holonomy groups SU(3), G2 and Spin(7) as suitable for compactification of superstrings, M-theory and F-theory (with only one time) respectively. The relations of these groups with the octonions are discussed, reinforcing their role in the physics of string theory and duality. We also exhibit three triple exact sequences exp

Paul Doukhan, Michael H. Neumann

We give an introduction to a notion of weak dependence which is more general than mixing and allows to treat for example processes driven by discrete innovations as they appear with time series bootstrap. As a typical example, we analyze autoregressive processes and their bootstrap analogues in detail and show how weak dependence can be easily derived from a

G. Boué, F. Durret, C. Adami, G. A. Mamon

We compare the distribution of optically and Halpha (Ha) selected galaxies in the Southern half of the nearby Abell 85 (A85) cluster with the recently discovered X-ray filament (XRF). We search for galaxies where star formation (SF) may have been triggered by interactions with intracluster gas or tidal pressure due to the cluster potential when entering the

W. H. T. Vlemmings, H. J. van Langevelde

Context: Magnetic fields are thought to be one of the possible mechanisms responsible for shaping the generally spherical outflow of evolved stars into often aspherical planetary nebulae. However, direct measurements of magnetic fields during the transition to the planetary nebula phase are rare. Aims: The aim of this project is to expand the number of magne

Fu-Yuan Wang, Bao-Sen Shi, Guang-Can Guo

We experimentally observe the two-photon interference of multimode photon pairs produced by an optical parametric oscillator far below threshold via a michelson interferometer, which shows a multipeaked structure. We find that the correlation function when the interferometer is unbalanced is clearly dependent on the path difference and phase between two inte

Toshihiko Masuda, Reiji Tomatsu

We classify a certain class of minimal actions of a compact Kac algebra with amenable dual on injective factors of type III. Our main technical tools are the structural analysis of type III factors and the theory of canonical extension of endomorphisms introduced by Izumi.

S. Pfalzner, J. Tackenberg, M. Steinhausen

The standard picture of accretion is a steady flow of matter from the disc onto the young star - a concept which assumes the star-disc system to be completely isolated. However, in a dense cluster environment star-disc systems do interact gravitationally. The aim here is to estimate the encounter-induced accretion rate in an ONC-like environment. Combining s

P. Bieliavsky, R. Gurau, V. Rivasseau

Quantum field theory has been shown recently renormalizable on flat Moyal space and better behaved than on ordinary space-time. Some models at least should be completely finite, even beyond perturbation theory. In this paper a first step is taken to extend such theories to non-flat backgrounds such as solvable symmetric spaces.

Fu-Yuan Wang, Bao-Sen Shi, Guang-Can Guo

We report the generation of a type-I multimode two-photon state on a rubidium D$_2$ line (780 nm) using periodically poled KTiOPO$_4$ crystals. With a degenerate optical parametric oscillator far below threshold, we observe an oscillatory correlation function, the cross-correlation between two photons shows a cavity bandwidth of about 7.8 MHz. We also use a

Izumi Hachisu, Mariko Kato, Angelo Cassatella

We present a unified model of infrared (IR), optical, ultraviolet (UV), and X-ray light curves for the 1983 outburst of GQ Muscae (Nova Muscae 1983) and estimate its white dwarf (WD) mass. Based on an optically thick wind model of nova outbursts, we model the optical and IR light curves with free-free emission, and the UV 1455 Åand supersoft X-ray light curv

Nemesio Rodriguez-Fernandez, Francoise Combes

The gas distribution and dynamics in the inner Galaxy present many unknowns as the origin of the asymmetry of the longitude-velocity (lv) diagram of the Central Molecular Zone (CMZ). On the other hand, there are recent evidences in the stellar component of the presence of a nuclear bar that could be slightly lopsided. Our goal is to characterize the nuclear

I. Horn

The reaction $γp\to pπ^0η$ has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction shows contributions from $Δ^+(1232)η$, $N(1535)^+π^0$ and $pa_0(980)$ as intermediate states. A partial wave analysis suggests that the reaction proceeds via formation of six $Δ$ resonances, $Δ(1600)P_{33}$, $Δ(

Manuel Bähr, Stefan Gieseke, Michael H. Seymour

In this contribution we describe a new model of multiple partonic interactions that has been implemented in Herwig++. Tuning its two free parameters we find a good description of CDF underlying event data. We show extrapolations to the LHC and discuss intrinsic PDF uncertainties.

Yoko Miura, Yukio Yasui, Taketo Moyoshi, Masatoshi Sato

Magnetic excitation spectra of quantum spins of Na3Cu2SbO6 with the distorted honeycomb structure have been measured by neutron inelastic scattering. The intensity distribution and the dispersion curves of the excitations indicate that the spin system can be well understood by considering one-dimensional spin chains formed of Cu2+ ions on a lattice of the al

Taichi Kato, Hiroyuki Maehara, Berto Monard

We report on the detection of very stable modulations with periods unexpectedly (~0.5%) longer than superhump periods during the slowly fading stage of WZ Sge-type superoutbursts in three systems, GW Lib, V455 And and WZ Sge. These periods are naturally explained by assuming that these modulations are superhumps arising from matter near the tidal truncation

Y. L. Xin, Ling Yang

We derive estimates of the Hessian of two smooth functions defined on Grassmannian manifold. Based on it, we can derive curvature estimates for minimal submanifolds in Euclidean space via Gauss map. In this way, the result for Bernstein type theorem done by Jost and the first author could be improved.

Maria J. P. Comuñas, Antoine Baylaucq, Christian Boned, Josefa Fernandez

This paper reports viscosity data for mixtures containing a refrigerant (HFC-134a) and a lubricant (triethylene glycol dimethyether, TriEGDME, or tetraethylene glycol dimethyl ether, TEGDME), at 12% of TriEGDME or 14% mass fraction of TEGDME. The measurements (140 data points) were obtained at various pressures (between 10 and 140 MPa) in the monophasic liqu

Sébastien Peirani, José Antonio De Freitas Pacheco

(context) Different cosmological data are consistent with an accelerated expansion produced by an exotic matter-energy component, dubbed "dark-energy''. A cosmological constant is a possibility since it satisfies most of the observational constraints. (aims) In this work, the consequences of such a component in the dynamics of groups of galaxies is investiga

Olivier Klein, G. De Loubens, V. V. Naletov, F. Boust

We review how a magnetic resonance force microscope (MRFM) can be applied to perform ferromagnetic resonance (FMR) spectroscopy of \emph{individual} sub-micron size samples. We restrict our attention to a thorough study of the spin-wave eigen-modes excited in permalloy (Py) disks patterned out of the same 43.3 nm thin film. The disks have a diameter of eithe

Jun Kataoka

In this review, I will discuss how to characterize synchrotron X-ray variability of TeV blazars by using the observed/simulated light curves. Apparently, temporal studies provide independent and complementary information to the spectral studies, but surprisingly little attention has been paid especially for the blazar study. Only exception is a classical arg

Roberto Casarin, Jean-Michel Marin

The aim of this paper is to compare three regularized particle filters in an online data processing context. We carry out the comparison in terms of hidden states filtering and parameters estimation, considering a Bayesian paradigm and a univariate stochastic volatility model. We discuss the use of an improper prior distribution in the initialization of the

Keiji Yada, Seiichiro Onari, Yukio Tanaka, Kazumasa Miyake

We present a microscopic theory of fluctuation-mediated pairing mechanism in a two-dimensional extended Hubbard model. In contrast to conventional wisdom, odd-frequency spin-triplet pairing can be stabilized near the spin-density-wave critical point. Favorable conditions for the odd-frequency pairing are the presence of geometrical frustration and off-site C

Jun Kataoka

In next five years, dramatic progress is anticipated for the AGN studies, as we have two important missions to observe celestial sources in the high energy regime: GLAST and Suzaku. In this talk, I will summarize recent highlights in studies of AGN jets, focusing on the high-sensitivity X-ray observations that may shed new light on the forthcoming GLAST era.

Keiichi Asada, Makoto Inoue, Masanori Nakamura, Seiji Kameno

We present results from multifrequency polarimetry of NRAO 140 using the Very Long Baseline Array. These observations allow us to reveal the distributions of both the polarization position angle and the Faraday rotation measure (RM). These distributions are powerful tools to discern the projected and line-of-sight components of the magnetic field, respective

Jingzhi Yan, Qingzhong Liu, Petr Hadrava

We present the results of the spectroscopic observations of HDE 226868, the optical counterpart to the black hole X-ray binary Cyg X-1, from 2001 to 2006. We analyze the variabilities of the two components in the complex H$α$ line: one P-Cygni shaped component which follows the motion of the supergiant and another emission component moving with an antiphase

Keiichi Asada, Makoto Inoue, Seiji Kameno, Hiroshi Nagai

The existence of a gradient in the Faraday rotation measure (RM) of the quasar 3C 273 jet is confirmed by follow-up observations. A gradient transverse to the jet axis is seen for more than 20 mas in projected distance. Taking account of the viewing angle, we estimate it to be more than 100 pc. Comparing to the distribution of the RM in 1995, we detect a tim

Pierre-Yves Longaretti

Astrophysical jets are widely believed to be self-collimated by the hoop-stress due to the azimuthal component of their magnetic field. However this implies that the magnetic field is largely dominated by its azimuthal component in the outer jet region. In the fusion context, it is well-known that such configurations are highly unstable in static columns, le

Jingzhi Yan, Qingzhong Liu, Hengrong Hang

We present the results of optical spectroscopic observations of CI Cam. Double-peaked profiles were simultaneously observed for the first time in the hydrogen Balmer, He {\small I} $λ$6678 and Fe {\small II} lines during an observational run in 2001 September. An intermediate viewing angle of the circumstellar disk around the B[e] star is consistent with our

Minho Choi, Kenji Hamaguchi, Jeong-Eun Lee, Ken&#39;ichi Tatematsu

The R CrA region was observed in the 3.5 and 6.2 cm continuum with high angular resolutions (0.6--1.7 arcseconds) using the Very Large Array. Archival data sets were also analyzed for comparison, which provided angular resolutions up to 0.3 arcseconds. A cluster of young stellar objects was detected, and a rich array of star forming activities was revealed.

E. B. Herbold, J. Kim, V. F. Nesterenko, S. Wang

One-dimensional nonlinear phononic crystals have been assembled from periodic diatomic chains of stainless steel cylinders alternated with Polytetrafluoroethylene (PTFE) spheres. We report the presence of acoustic band gaps in the dispersion relation of the linearized systems and study the transformation of single and multiple pulses in linear, nonlinear and

Zonghua Liu, Baowen Li

We study vibrational energy transport in a quasi 1-D harmonic chain with both longitudinal and transverse vibrations. We demonstrate via both numerical simulation and theoretic analysis that for 1-D atomic chain connected by 3D harmonic springs, the coefficient of heat conduction changes it continuously with its lattice constant, indicating the qualitative d

Dongliang Wang, Yanwei Ma, Zhaoshun Gao, Xianping Zhang

We report on significant flux pinning enhancement in MgB2/Fe tapes that has been easily obtained by a simple and cheap route using acetone as both an efficient ball-milling medium and liquid additive through the in situ method. Results showed that the highly reactive C released from the decomposition of the acetone substituted into B sites, accompanied by th

Mirela Damian, Sriram V. Pemmaraju

We present a new efficient localized algorithm to construct, for any given quasi-unit disk graph G=(V,E) and any e > 0, a (1+e)-spanner for G of maximum degree O(1) and total weight O(w(MST)), where w(MST) denotes the weight of a minimum spanning tree for V. We further show that similar localized techniques can be used to construct, for a given unit disk gra

James Hirschorn

A strong antidiamond principle (*c) is shown to be consistent with CH. This principle can be stated as a &#34;P-ideal dichotomy&#34;: every P-ideal on omega-1 (i.e. an ideal that is sigma-directed under inclusion modulo finite) either has a closed unbounded subset of omega-1 locally inside of it, or else has a stationary subset of omega-1 orthogonal to it. W

Chenguang Ye, Jing Zhang

We investigate experimentally the absorptive and dispersive properties of triple-resonant optical parametric amplifier OPA for the degenerate subharmonic field. In the experiment, the subharmonic field is utilized as the probe field and the harmonic wave as the pump field. We demonstrate that EIT-like effect can be simulated in the triple-resonant OPA when t

Toshiya Takami, Hiroshi Fujisaki

Rotating-wave approximation and its validity in multi-state quantum systems are studied through analytic approach. Their applicability is also verified from the viewpoint of generic states by the use of direct numerical integrations of the Schroedinger equation. First, we introduce an extension of the rotating-wave approximation for multi-state systems. Unde

Y. Kohama, Y. Kamihara, S. Riggs, F. F. Balakirev

The electrical resistivity and Hall coefficient of LaFeAsO0.95F0.05 polycrystalline samples were measured in pulsed magnetic fields up to m0H = 60 T from room temperature to 1.5 K. The resistance of the normal state shows a negative temperature coefficient (dr/dT < 0) below 70 K for this composition, indicating insulating ground state in underdoped LaFeAsO s

Agata M Branczyk, T. C. Ralph

We present an analysis of squeezed single photon states as a resource for teleportation of coherent state qubits and propose proof-of-principle experiments for the demonstration of coherent state teleportation and entanglement swapping. We include an analysis of the squeezed vacuum as a simpler approximation to small-amplitude cat states. We also investigate

Amihay Hanany, Noppadol Mekareeya, Alberto Zaffaroni

Partition functions for M2-brane theories in various backgrounds are computed. We consider in particular configurations of membranes at orbifold singularities preserving N=5 or N=6 supersymmetry. The worldvolume membrane theory for some of these configurations has been recently constructed in terms of N=6 Chern-Simons theories. The detailed structure of the