March 2008 arXiv papers — page 32

S. Ashhab, J. R. Johansson, A. M. Zagoskin, Franco Nori

We consider a system composed of a single artificial atom coupled to a cavity mode. The artificial atom is biased such that the most dominant relaxation process in the system takes the atom from its ground state to its excited state, thus ensuring population inversion. A recent experimental manifestation of this situation was achieved using a voltage-biased

T. Kato, T. Maruyama, S. Okitsu, H. Sakata

Scanning tunneling microscopy and spectroscopy have been performed on superconducting La$_{2-x}$Sr$_{x}$CuO$_{4}$ ($x=0.06, 0.12, 0.16$, and 0.21) at 4.2 K. Atomically resolved surface topography has been observed on the $ab$ surface, which exhibits a one-dimensional structure corresponding to the buckling pattern of the orthorhombic phase. The tunneling spe

Bartosz Lew

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying size and shape and measure the first four moments of the one-point distribution within these regions, and using their simul

Thomas M. Fiore, Po Hu, Igor Kriz

We define a general concept of pseudo algebras over theories and 2-theories. A more restrictive such notion was introduced by Hu and Kriz, but as noticed by M. Gould, did not capture the desired examples. The approach taken in this paper corrects the mistake by introducing a more general concept, allowing more flexibility in selecting coherence diagrams for

Jens Hoppe, Douglas Lundholm, Maciej Trzetrzelewski

A certain G_2 times U(1) invariant Hamiltonian arising from the standard membrane matrix model via conjugating any of the supercharges by a cubic, octonionic, exponential is proven to have a spectrum covering the whole positive half-axis. The model could be useful in determining a normalizable zero-energy state in the original SO(9) invariant SU(N) matrix mo

Yasuhisa Inada, Munekazu Horikoshi, Shuta Nakajima, Makoto Kuwata-Gonokami

We detected the formation of p-wave Feshbach molecules for all three combinations of the two lowest atomic spin states of 6Li. By creating a pure molecular sample in an optical trap, we measured the inelastic collision rates of p-wave molecules. The elastic collision rate was measured from the thermalization rate of a breathing mode excited spontaneously upo

M. Czakon

I present the two-loop QCD corrections to the production of a massive quark-anti-quark pair in the massless quark-anti-quark annihilation channel. The result is obtained as a combination of a deep expansion in the mass around the high energy limit and of a numerical integration of a system of differential equations. The primary application of the outcome and

Thomas Buchert, Mauro Carfora

We discuss the effect of curvature and matter inhomogeneities on the averaged scalar curvature of the present-day Universe. Motivated by studies of averaged inhomogeneous cosmologies, we contemplate on the question whether it is sensible to assume that curvature averages out on some scale of homogeneity, as implied by the standard concordance model of cosmol

Hillary S. W. Han, Christian M. Reidys

In this paper we study $k$-noncrossing RNA structures with minimum arc-length 4 and at most $k-1$ mutually crossing bonds. Let ${\sf T}_{k}^{[4]}(n)$ denote the number of $k$-noncrossing RNA structures with arc-length $\ge 4$ over $n$ vertices. We prove (a) a functional equation for the generating function $\sum_{n\ge 0}{\sf T}_{k}^{[4]}(n)z^n$ and (b) deriv

Jaiseung Kim, Pavel Naselsky, Per Rex Christensen

We are presenting an Internal Linear Combination (ILC) CMB map, in which the foreground is reduced through harmonic variance minimization. We have derived our method by converting a general form of pixel-space approach into spherical harmonic space, maintaining full correspondence. By working in spherical harmonic space, spatial variability of linear weights

Eike Lau

A p-divisible group over a complete local domain determines a Galois representation on the Tate module of its generic fibre. We determine the image of this representation for the universal deformation in mixed characteristic of a bi-infinitesimal group and for the p-rank strata of the universal deformation in positive characteristic of an infinitesimal group

Christian Pries

We give a short discussion about a weaker form of minimality (called quasi-minimality). We call a system quasi-minimal if all dense orbits form an open set. It is hard to find examples which are not already minimal. Since elliptic behaviour makes them minimal, these systems are regarded as parabolic systems. Indeed, we show that a quasi-minimal homeomorphism

S. Weyeneth, T. Schneider, Z. Bukowski, J. Karpinski

We present reversible magnetization data of a YBa2Cu4O8 single crystal and analyze the evidence for 3D-xy critical behavior and a magnetic field induced 3D to 1D crossover. Remarkable consistency with these phenomena is observed in agreement with a magnetic field induced finite size effect, whereupon the correlation length transverse to the applied magnetic

Vladimir Khachatryan

We investigate modification of Kolmogorov wave turbulence in QCD calculating gluon spectra as functions of time in the presence of a low energy source which feeds in energy density in the infrared region at a time-dependent rate. Then considering the picture of saturation constraints as has been constructed in the "bottom-up" thermalization approach

Laurent Ducrohet

Let X be a general proper and smooth curve of genus 2 (resp. of genus 3) defined over an algebraically closed field of characteristic p. When 3\leq p \leq 7, the action of Frobenius on rank 2 semi-stable vector bundles with trivial determinant is completely determined by its restrictions to the 30 lines (resp. the 126 Kummer surfaces) that are invariant unde

A. Karahalios, A. Metavitsiadis, X. Zotos, A. Gorczyca

Using numerical diagonalization techniques, we explore the effect of local and bond disorder on the finite temperature spin and thermal conductivities of the one dimensional anisotropic spin-1/2 Heisenberg model. High-temperature results for local disorder show that the dc conductivties are finite, apart from the uncorrelated - XY case - where dc transport v

D. Dudal, J. A. Gracey, S. P. Sorella, N. Vandersickel

We demonstrate that the inversion method can be a very useful tool in providing an infrared stabilization of 3D gauge theories, in combination with the mass operator $A^2$ in the Landau gauge. The numerical results will be unambiguous, since the corresponding theory is ultraviolet finite in dimensional regularization, making a renormalization scale or scheme

J. Suhonen, O. Civitarese

In this work we use the recently measured neutron occupancies in the 76Ge and 76Se nuclei as a guideline to define the neutron quasiparticle states in the 1p0f0g shell. We define the proton quasiparticles by inspecting the odd-mass nuclei adjacent to 76Ge and 76Se. We insert the resulting quasiparticles in a proton-neutron quasiparticle random-phase approxim

G. G. Nyambuya

This reading expounds with expediency on the recently proposed Azimuthally Symmetric Theory of Gravitation (ASTG) set-up earlier. At its inspection, it was demonstrated that the ASTG is capable (among others solar anomalies) of explaining the precession of the perihelion of solar planets. In the present, we show that the ASTG is capable of explaining the puz

Keiju Murata, Jiro Soda

We study the stability of five-dimensional Myers-Perry black holes with equal angular momenta which have an enlarged symmetry, U(2). Using this symmetry, we derive master equations for a part of metric perturbations which are relevant to the stability. Based on the master equations, we prove the stability of Myers-Perry black holes under these perturbations.

Christian Boehmer, Felix Karbstein, Michael Thies

Baryons in the massive Nambu-Jona-Lasinio model in 1+1 dimensions (the massive chiral Gross-Neveu model) are studied in the limit of an infinite number of flavors. The baryon mass is evaluated for a wide range of bare fermion masses and filling fractions, combining analytical asymptotic expansions with a full numerical Hartree-Fock calculation.

Petr Hajicek

The paper starts with the proposal that the cause of the apparent insolubility of the free-will problem are several popular but strongly metaphysical notions and hypotheses. To reduce the metaphysics, some ideas are borrowed from physics. A concept of event causality is discussed. The importance of Hume's Principle of Causality is stressed and his Princi

Matus Medo, Yury M. Pis'mak, Yi-Cheng Zhang

Financial markets, with their vast range of different investment opportunities, can be seen as a system of many different simultaneous games with diverse and often unknown levels of risk and reward. We introduce generalizations to the classic Kelly investment game [Kelly (1956)] that incorporates these features, and use them to investigate the influence of d

Jean Pierre Petit, Gilles d'Agostini

The Universe, far to be homogenous, expands in large empty bubbles of the large-scale structure, but not in mass concentrations like galaxies, so that the Robertson-Walker solution does not fit. We suggest that a symmetry breaking occurred in a distant past, during the radiation-dominated era. Before, the three-dimensional hypersurface was invariant under th

P. E. Jönsson, R. Mathieu, W. Wernsdorfer, A. M. Tkachuk

We show in this comment that the claim by Ancona-Torres et al. of an equilibrium quantum or classical phase transition in the LiHo$_x$Y$_{1-x}$F$_4$ system is not supported by a rigorous scaling analysis.

Guenther Ruediger, Manfred Schultz, Michael Mond, Dmitry A. Shalybkov

Collapse calculations indicate that the hot newly born protoneutron stars (PNS) rotate differentially so that strong toroidal magnetic field components should exist in the outer crust where also the Hall effect appears to be important when the Hall parameter \hatβ=ω_B τis of order unity. The amplitudes of the induced toroidal magnetic fields are limited from

Takuro Mochizuki

We study (i) asymptotic behaviour of wild harmonic bundles, (ii) the relation between semisimple meromorphic flat connections and wild harmonic bundles, (iii) the relation between wild harmonic bundles and polarized wild pure twistor $D$-modules. As an application, we show the hard Lefschetz theorem for algebraic semisimple holonomic $D$-modules, conjectured

Victor Mukherjee, Amit Dutta, Diptiman Sen

We study the quenching dynamics of a one-dimensional spin-1/2 $XY$ model in a transverse field when the transverse field $h(=t/τ)$ is quenched repeatedly between $-\infty$ and $+\infty$. A single passage from $h \to - \infty$ to $h \to +\infty$ or the other way around is referred to as a half-period of quenching. For an even number of half-periods, the trans

Tadas K. Nakamura

The energy source of the radiation in Unruh/Hawking process is investigated with emphasis on the particle number definition based on conservation laws. It has been shown that the particle radiation is not the result of pair creation by the gravitational force, but the result of difference in the conservation laws to define the particle number. The origin of

Arvind R. Subramaniam, Ilya A. Gruzberg, Andreas W. W. Ludwig

Multifractal scaling of critical wave functions at a disorder-driven (Anderson) localization transition is modified near boundaries of a sample. Here this effect is studied for the example of the spin quantum Hall plateau transition using the supersymmetry technique for disorder averaging. Upon mapping of the spin quantum Hall transition to the classical per

Amos Sharoni, Juan Gabriel Ramírez, Ivan K. Schuller

The metal insulator transition of nano-scaled $VO_2$ devices is drastically different from the smooth transport curves generally reported. The temperature driven transition occurs through a series of resistance jumps ranging over 2 decades in amplitude, indicating that the transition is caused by avalanches. We find a power law distribution of the jump ampli

W. F. Chen

We introduce the historical development and physical idea behind topological Yang-Mills theory and explain how a physical framework describing subatomic physics can be used as a tool to study differential geometry. Further, we emphasize that this phenomenon demonstrates that the interrelation between physics and mathematics have come into a new stage.

Takashi Hashimoto

Let Alt_n be the vector space of all alternating n-by-n complex matrices, on which the complex general linear group GL_n acts by $x \mapsto g x g^t$. The aim of this paper is to show that Pfaffian of a certain matrix whose entries are multiplication operators or derivations acting on polynomials on Alt_n provides a generating function for the GL_n-invariant

Shuang-Qing Wu, Jun-Jin Peng, Zhan-Yue Zhao

Motivated by the universality of Hawking radiation and that of the anomaly cancellation technique as well as that of the effective action method, we investigate the Hawking radiation of a Schwarzschild black hole in the isotropic coordinates via the cancellation of gravitational anomaly. After performing a dimensional reduction from the four-dimensional isot

Manabu Takahashi, Junichi Igarashi, Takuji Nomura

We present a detailed analysis of the incident-photon-energy and polarization dependences of the resonant inelastic x-ray scattering (RIXS) spectra at the Cu $K$ edge in La$_{2}$CuO$_{4}$. Our analysis is based on the formula developed by Nomura and Igarashi, which describes the spectra by a product of an incident-photon-dependent factor and a density-densit

Robin Endelman, Manash Mukherjee

An approach to representations of finite groups is presented without recourse to character theory. Considering the group algebra C[G] as an algebra of linear maps on C[G] (by left multiplication), we derive the primitive central idempotents as a simultaneous eigenbasis of the centre, Z(C[G]). We apply this framework to obtain the irreducible representations

Yuanjie Du, R. X. Xu, G. J. Qiao, J. L. Han

Pulsars have been recognized as normal neutron stars or quark stars. Sub-millisecond pulsars, if detected, would play an essential and important role in distinguishing quark stars from neutron stars. A key question is how sub-millisecond pulsars could form. Both sub-Keplerian (for neutron and quark stars) and super-Keplerian cases (only for quark stars, whic

Daniel Ford, Tanja Gernhard, Frederick Matsen

In this paper we present a new way to understand the timing of branching events in phylogenetic trees. Our method explicitly considers the relative timing of diversification events between sister clades; as such it is complimentary to existing methods using lineages-through-time plots which consider diversification in aggregate. The method looks for evidence

W. Lee Powell, Ronald Wilhelm, Kenneth Carrell, Amy Westfall

We obtained new UBV photometry and spectroscopy of Blue Plume (BP) stars in fields near the center of the Canis Major Over-Density (CMa). We combined analysis of the color-color diagrams with a new comparison of the hydrogen Balmer-line profile to the reddening-free Q parameter to improve the reddening and extinction estimates for this low-latitude, differen

Stefano Beltraminelli, Danilo Merlini, Sergey Sekatskii

In this note concerning integrals involving the logarithm of the Riemann Zeta function, we extend some treatments given in previous pioneering works on the subject and introduce a more general set of Lorentz measures. We first obtain two new equivalent formulations of the Riemann Hypothesis (RH). Then with a special choice of the measure we formulate the RH

Bruno Merin, Jes Jorgensen, Loredana Spezzi, Juan M. Alcala

We present c2d Spitzer/IRAC observations of the Lupus I, III and IV dark clouds and discuss them in combination with optical and near-infrared and c2d MIPS data. With the Spitzer data, the new sample contains 159 stars, 4 times larger than the previous one. It is dominated by low- and very-low mass stars and it is complete down to M $\approx$ 0.1M$_\odot$. W

M. Benarous

We derive variationally the HFB equations for a trapped self-interacting Bose gas at finite temperature. In the Thomas-Fermi limit, we obtain simple expressions for the condensate, the non condensate and the anomalous densities. Their behavior in terms of the condensate fraction meets qualitatively the experimental data. In particular, the non condensate and

Dean B. Krafft, Aaron Birkland, Ellen J. Cramer

NCore is an open source architecture and software platform for creating flexible, collaborative digital libraries. NCore was developed by the National Science Digital Library (NSDL) project, and it serves as the central technical infrastructure for NSDL. NCore consists of a central Fedora-based digital repository, a specific data model, an API, and a set of

Kishore T. Kapale, Girish S. Agarwal

We study multipartite entanglement in non-equilibrium quantum phase transition (NEQPT) attainable in a coherently driven atomic ensemble undergoing collective decay. The NEQPT arises in the steady state of the system as the drive field strength is varied in comparison with the decay parameter. A close connection is observed between the critical behavior and

M. Iskin, C. A. R. S á de Melo

We analyze the finite temperature phase diagram of fermion mixtures in one-dimensional optical lattices as a function of interaction strength. At low temperatures, the system evolves from an anisotropic three-dimensional Bardeen-Cooper-Schrieffer (BCS) superfluid to an effectively two-dimensional Berezinskii-Kosterlitz-Thouless (BKT) superfluid as the intera

H. Alloul, I. R. Mukhamedshin, G. Collin, N. Blanchard

We have synthesized and characterized four different stable phases of Na ordered Na$_{x}$CoO$_{2}$, for $0.65<x<0.8$. Above 100 K they display similar Curie-Weiss susceptibilities as well as ferromagnetic $q=0$ spin fluctuations in the CoO$_{2}$ planes revealed by $^{23}$Na NMR data. In all phases from $^{59}$Co NMR data we display evidences that the Co disp

Shui Feng, Byron Schmuland, Jean Vaillancourt, Xiaowen Zhou

Reversibility of the Fleming-Viot process with mutation, selection, and recombination is well understood. In this paper, we study the reversibility of a system of Fleming-Viot processes that live on a countable number of colonies interacting with each other through migrations between the colonies. It is shown that reversibility fails when both migration and

Devdeep Sarkar, Paolo Serra, Asantha Cooray, Kiyotomo Ichiki

Weak gravitational lensing by foreground density perturbations generates a gradient mode in the shear of background images. In contrast, cosmological tensor perturbations induce a non-zero curl mode associated with image rotations. In this note, we study the lensing signatures of both primordial gravitational waves from inflation and second-order gravitation

Niv Drory, Marcelo Alvarez

We present a formalism to infer the presence of merging by comparing the time derivative of the observed galaxy stellar mass function (MF) to the change of the MF expected from the star formation rate (SFR) in galaxies as a function of mass and time. We present the SFR in as a function of stellar mass and time spanning 9<logM<12 and 0<z<5. We show that at z>

J. C. Xavier, E. Dagotto

The Kondo lattice model enlarged by an antiferromagnetic coupling $J_{\rm AF}$ between the localized spins is here investigated using computational techniques. Our results suggest the existence of a d-wave superconducting phase close to half-filling mediated by antiferromagnetic fluctuations. This establishes a closer connection between theory and heavy ferm

A. Tannirkulam, J. D. Monnier, R. Millan-Gabet, T. J. Harries

Using the longest optical-interferometeric baselines currently available, we have detected strong near-infrared (NIR) emission from inside the dust-destruction radius of Herbig Ae stars MWC275 and AB Aur. Our sub-milli-arcsecond resolution observations unambiguously place the emission between the dust-destruction radius and the magnetospheric co-rotation rad

Genevieve J. Graves, Ricardo P. Schiavon

We present a method for determining mean light-weighted ages and abundances of Fe, Mg, C, N, and Ca, from medium resolution spectroscopy of unresolved stellar populations. The method, pioneered by Schiavon (2007), is implemented in a publicly available code called EZ_Ages. The method and error estimation are described, and the results tested for accuracy and

S. Diehl, A. Micheli, A. Kantian, B. Kraus

An open quantum system, whose time evolution is governed by a master equation, can be driven into a given pure quantum state by an appropriate design of the system-reservoir coupling. This points out a route towards preparing many body states and non-equilibrium quantum phases by quantum reservoir engineering. Here we discuss in detail the example of a \emph

Alexander Drewitz

We consider the solution $u$ to the one-dimensional parabolic Anderson model with homogeneous initial condition $u(0, \cdot) \equiv 1$, arbitrary drift and a time-independent potential bounded from above. Under ergodicity and independence conditions we derive representations for both the quenched Lyapunov exponent and, more importantly, the $p$-th annealed L

Mark S. Marley, S. K. Leggett

Ultracool dwarfs exhibit a remarkably varied set of characteristics which hint at the complex physical processes acting in their atmospheres and interiors. Spectra of these objects not only depend upon their mass and effective temperature, but also their atmospheric chemistry, weather, and dynamics. As a consequence divining their mass, metallicity and age s

David C. Dobson, Lyubima B. Simeonova

Recently, there has been plenty of work in designing and fabricating materials with an effective negative refractive index. Veselago realized that a slab of material with a refractive index of -1 would act as a lens. Pendry suggested that the Veselago lens would act as a superlens, providing a perfect image of an object in contrast to conventional lenses whi

Marcos Curty, Kiyoshi Tamaki, Tobias Moroder

We investigate limitations imposed by detector dead-times on the performance of sequential attacks against a differential-phase-shift (DPS) quantum key distribution (QKD) protocol with weak coherent pulses. In particular, we analyze sequential attacks based on unambiguous state discrimination of the signal states emitted by the source and we obtain ultimate

J. F. Vieira, S. F. Martins, F. Fiuza, R. A. Fonseca

Three-dimensional Particle-in-Cell (PIC) simulations with the code QuickPIC are used to illustrate the typical accelerating structures associated with the interaction of an intense laser beam with an underdense plasma in the blowout regime. Our simulations are performed with an externally injected electron beam, positioned in the region of maximum accelerati

Koon-Kiu Yan, Dylan Walker, Sergei Maslov

We consider two types of fluctuations in the mass-action equilibrium in protein binding networks. The first type is driven by relatively slow changes in total concentrations (copy numbers) of interacting proteins. The second type, to which we refer to as spontaneous, is caused by quickly decaying thermodynamic deviations away from the equilibrium of the syst

M. Poggio, M. P. Jura, C. L. Degen, M. A. Topinka

Recent advances in the fabrication of microelectromechanical systems (MEMS) and their evolution into nanoelectromechanical systems (NEMS) have allowed researchers to measure extremely small forces, masses, and displacements. In particular, researchers have developed position transducers with resolution approaching the uncertainty limit set by quantum mechani

G. Bertelli, L. Girardi, P. Marigo, E. Nasi

Tracks and isochrones have been computed in the range of initial masses 0.15 - 20 Mo for a grid of 39 chemical compositions with the metal content Z between 0.0001 and 0.070, and helium content Y between 0.23 and 0.46. The Padova stellar evolution code has been implemented with updated physics. New synthetic TP-AGB models allow the extension of stellar model

S. E. Ahnert, D. Garlaschelli, T. M. A. Fink, G. Caldarelli

In recent work we presented a new approach to the analysis of weighted networks, by providing a straightforward generalization of any network measure defined on unweighted networks. This approach is based on the translation of a weighted network into an ensemble of edges, and is particularly suited to the analysis of fully connected weighted networks. Here w

Y. Brihaye, T. Delsate

We consider non-topological, &#34;bell-shaped&#34; localized and regular solutions available in some 1+1 dimensional scalar field theories. Several properties of such solutions are studied, namely their stability and the occurence of fermion bound states in the background of a kink and a kink-anti-kink solutions of the sine-Gordon model.

Catherine Recanati

We give a brief overview of the main characteristics of diagrammatic reasoning, analyze a case of human reasoning in a mastermind game, and explain why hybrid representation systems (HRS) are particularly attractive and promising for Artificial General Intelligence and Computer Science in general.

Satish Babu Korada, Nicolas Macris

We consider multiple access communication on a binary input additive white Gaussian noise channel using randomly spread code division. For a general class of symmetric distributions for spreading coefficients, in the limit of a large number of users, we prove an upper bound on the capacity, which matches a formula that Tanaka obtained by using the replica me

Peter Major

In this paper I prove good estimates on the moments and tail distribution of $k$-fold Wiener--Itô integrals and also present their natural counterpart for polynomials of independent Gaussian random variables. The proof is based on the so-called diagram formula for Wiener--Itô integrals which yields a good representation for their products as a sum of such in

C. Milardi

DAFNE, the Frascati F-factory, has recently completed experimental runs for the three main detectors, KLOE, FINUDA and DEAR achieving 1.6x10E+32 cm-2s-1 peak and 10 pb-1 daily integrated luminosities. Improving these results by a significant factor requires changing the collision scheme. For this reason, in view of the SIDDHARTA detector installation, releva

S. A. Abel, M. D. Goodsell, J. Jaeckel, V. V. Khoze

Embeddings of the standard model in type II string theory typically contain a variety of U(1) gauge factors arising from D-branes in the bulk. In general, there is no reason why only one of these - the one corresponding to weak hypercharge - should be massless. Observations require that standard model particles must be neutral (or have an extremely small cha

A. F. Borghesani

A new analysis and new Molecular Dynamics (MD) simulations of the measurements of the mobility $μ_{i}$ of O$_{2}^{-} $ ions in dense supercritical Ar gas are reported. $μ_{i}$ shows a marked dependence on the distance from the critical temperature $T_{c}.$ A mobility defect appears as a function of the gas density and its maximum value occurs below the criti

R. Rajesh, Vinod Sharma

We consider the problem of transmission of several distributed sources over a multiple access channel (MAC) with side information at the sources and the decoder. Source-channel separation does not hold for this channel. Sufficient conditions are provided for transmission of sources with a given distortion. The source and/or the channel could have continuous

Robert D. Batten, Frank H. Stillinger, Salvatore Torquato

Using a collective coordinate numerical optimization procedure, we construct ground-state configurations of interacting particle systems in various space dimensions so that the scattering of radiation exactly matches a prescribed pattern for a set of wave vectors. We show that the constructed ground states are, counterintuitively, disordered (i.e., possess n

R. Smolec

As a by-product of beta Cephei and delta Cephei radiative model surveys we have found interesting cases of multimode pulsation. In case of beta Cephei stars, we found two multimode domains with two or three modes being involved. The origin of the multimode pulsation can be traced to one of the two different mechanisms: either to the non-resonant coupling of

M. Krumpe, G. Lamer, A. Corral, A. D. Schwope

We present the results of the X-ray spectral analysis of an XMM-Newton-selected type II QSO sample with z>0.5 and 0.5-10 keV flux of 0.3-33 x 10^{-14} erg/s/cm^2. The distribution of absorbing column densities in type II QSOs is investigated and the dependence of absorption on X-ray luminosity and redshift is studied. We inspected 51 spectroscopically classi

Maciej Blaszak, Burcu Silindir, Blazej M. Szablikowski

A general unifying framework for integrable soliton-like systems on time scales is introduced. The $R$-matrix formalism is applied to the algebra of $δ$-differential operators in terms of which one can construct infinite hierarchy of commuting vector fields. The theory is illustrated by two infinite-field integrable hierarchies on time scales which are diffe

Andrei Fluerasu, Abdellatif Moussaid, Henri Gleyzolle, Peter Falus

X-ray photon correlation spectroscopy was used to probe the diffusive dynamics of colloidal particles in a shear flow. Combining X-ray techniques with microfluidics is an experimental strategy that reduces the risk of x-ray induced beam damage and also allows time-resolved studies of processes taking place in flowcells. The experimental results and theoretic

Pierre Delage, Yu-Jun Cui, Pierre Antoine

Special problems were encountered in some areas in Northern France where the high speed railways (TGV Nord) crossed some loess deposits that appeared to be specially sensitive to change in water content and susceptible to collapse. Numerous sinkholes appeared along some sections of the line following wet climatic periods. After a general geological and geote

G. Bourda, P. Charlot, R. Biancale

A rigorous approach to simultaneously determine a Terrestrial Reference Frame (TRF) and Earth Orientation Parameters (EOP) is now currently applied on a routine basis in a coordinated project within the Groupe de Recherches de Géodésie Spatiale (GRGS) in France. Observations of the various space geodetic techniques (VLBI, SLR, LLR, DORIS and GPS) are separat

G. Bourda, P. Charlot, R. Biancale

In the framework of the &#34;Groupe de Recherches de Géodésie Spatiale&#34; (GRGS), a rigorous combination of the data from five space geodetic techniques (VLBI, GPS, SLR, LLR and DORIS) is routinely applied to simultaneously determine a Terrestrial Reference Frame (TRF) and Earth Orientation Parameters (EOP). This analysis is conducted with the software pac

Jawad Abuhlail

Given a coalgebra $C$ over a commutative ring $R,$ we show that $C$ can be considered as a (not necessarily counital) $C^{\ast op}$-coring. Moreover, we show that this coring has a left (right) counity if and only if $C$ is coseparable as an $R$-coalgebra.

A. Ballesteros, E. Celeghini, M. A. del Olmo

Applications of algebras in physics are related to the connection of measurable observables to relevant elements of the algebras, usually the generators. However, in the determination of the generators in Lie algebras there is place for some arbitrary conventions. The situation is much more involved in the context of quantum algebras, where inside the quantu

A. G. Meshkov

Nonlocal symmetries for exactly integrable two-field evolutionary systems of the third order have been computed. Differentiation of the nonlocal symmetries with respect to spatial variable gives a few nonevolutionary systems for each evolutionary system. Zero curvature representations for some new nonevolution systems are presented.

Eric Lantz, Jean Luc Blanchet, Luca Furfaro, Fabrice Devaux

A multi-imaging strategy is proposed and experimentally tested to improve the accuracy of photon counting with an electron multiplying charge-coupled device (EMCCD), by taking into account the random nature of its on-chip gain and the possibility of multiple photo-detection events on one pixel. This strategy is based on Bayesian estimation on each image, wit

Ahmad Shariati, Mohammad Khorrami, Amir H. Fatollahi

The possibility is examined that a model based on space noncommutativity of linear type can explain why photons from distant sources with multi-TeV energies can reach earth. In particular within a model in which space coordinates satisfy the algebra of SU(2) Lie group, it is shown that there is the possibility that the pair production through the reaction of

P. Delogu, M. E. Fantacci, P. Kasae, A. Retico

The computer-aided diagnosis system we developed for the mass characterization is mainly based on a segmentation algorithm and on the neural classification of several features computed on the segmented mass. Mass segmentation plays a key role in most computerized systems. Our technique is a gradient-based one, showing the main characteristic that no free par

M. Czakon

I review the recent progress in the evaluation of two-loop massive QCD amplitudes necessary for the description of hadronic scattering processes at the LHC. I put a special emphasis on the case of top-quark final states.

Antonio Di Crescenzo

A method yielding simple relationships among bilateral birth-and-death processes is outlined. This allows one to relate birth and death rates of two processes in such a way that their transition probabilities, first-passage-time densities and ultimate crossing probabilities are mutually related by some product-form expressions.

Ellyn K. Baines, Harold A. McAlister, Theo A. ten Brummelaar, Nils H. Turner

We have measured the angular diameters for a sample of 24 exoplanet host stars using Georgia State University&#39;s CHARA Array interferometer. We use these improved angular diameters together with Hipparcos parallax measurements to derive linear radii and to estimate the stars&#39; evolutionary states.

Nestor Sanchez, Eugenio Lopez

We study the thermal equilibrium and stability of isobaric, spherical structures having a radiation source located at its center. The thermal conduction coefficient, external heating and cooling rates are represented as power laws of the temperature. The internal heating decreases with distance from the source r approximately as exp(-tau)/(r**2), being tau t

E. Kierig, U. Schnorrberger, A. Schietinger, J. Tomkovic

We report on the first direct observation of coherent control of single particle tunneling in a strongly driven double well potential. In our setup atoms propagate in a periodic arrangement of double wells allowing the full control of the driving parameters such as frequency, amplitude and even the space-time symmetry. Our experimental findings are in quanti

Tiago P. Peixoto, Joern Davidsen

We numerically study the dynamics of a discrete spring-block model introduced by Olami, Feder and Christensen (OFC) to mimic earthquakes and investigate to which extent this simple model is able to reproduce the observed spatiotemporal clustering of seismicty. Following a recently proposed method to characterize such clustering by networks of recurrent event

H. J. Voelk, E. G. Berezhko, L. T. Ksenofontov

The consequences of a newly suggested value for the SN explosion energy 1.2x10^{51} erg are explored for the case of Tycho&#39;s supernova remnant (SNR). A nonlinear kinetic theory of cosmic ray (CR) acceleration in SNRs is employed to investigate the properties of Tycho&#39;s SNR and their correspondence to the existing experimental data. It is demonstrated

jorgen cherly

We obtain using exponential quadratic sums, explicit expressions for the number of triple persymmetric matrices over F_2 of given rank. (A matrix [a(i,j)] is persymmetric if a(i,j) = a(r,s) for i+j = r+s)

A. Kudlinski, G. Bouwmans, Y. Quiquempois, A. Mussot

We demonstrate experimentally that the spectral broadening of CW supercontinuum can be controlled by using photonic crystal fibers with two zero-dispersion wavelengths pumped by an Yb fiber laser at 1064 nm. The spectrum is bounded by two dispersive waves whose spectral location depends on the two zero-dispersion wavelengths of the fiber. The bandwidth of th

G. Bourda, J. Boehm, R. Heinkelmann, H. Schuh

The IAU/IUGG Working Group on &#34;Nutation for a non-rigid Earth&#34;, led by Véronique Dehant, won the European Descartes Prize in 2003, for its work developing a new model for the precession and the nutations of the Earth. This model (MHB2000, Mathews et al. 2002) was adopted by the IAU (International Astronomical Union) during the General Assembly in Man

G. Bourda, P. Charlot, R. Porcas, S. Garrington

The space astrometry mission GAIA will construct a dense optical QSO-based celestial reference frame. For consistency between the optical and radio positions, it will be important to align the GAIA frame and the International Celestial Reference Frame (ICRF) with the highest accuracy. Currently, it is found that only 10% of the ICRF sources are suitable to e

A. Krzysztof Kwaśniewski, Ewa Krot-Sieniawska

A research problem for undergraduates and graduates is being posed as a cap for the prior antecedent regular discrete mathematics exercises. [Here cap is not necessarily CAP=Competitive Access Provider, though nevertheless ...] The object of the cap problem of final interest i.e. array of fibonomial coefficients and the issue of its combinatorial meaning is

Feng-Kun Guo, Christoph Hanhart, Ulf-G. Meißner

We demonstrate that the experimental information currently available for the Y(4660) is consistent with its being a f_0(980)psi&#39; molecule. Possible experimental tests of our hypothesis are presented.

Andrei Khrennikov

In this paper we present a simple algorithm for representation of statistical data of any origin by complex probability amplitudes. Numerical simulation with Mathematica-6 is performed. The Bloch&#39;s sphere is used for visualization of results of numerical simulation. On the one hand, creation of such a quantum-like (QL) representation and its numerical ap

Nestor Sanchez, Emilio J. Alfaro, Enrique Perez

The Interstellar Medium seems to have an underlying fractal structure, which can be characterized through its fractal dimension (Df). However, several factors may affect the determination of Df, such as distortions due to projection, low image resolution, opacity of the cloud, and low signal-to-noise ratio. Here we use both simulated clouds and real molecula

Igor N. Mishustin

In this talk I discuss properties of hot stellar matter at sub-nuclear densities which is formed in supernova explosions. I emphasize that thermodynamic conditions there are rather similar to those created in the laboratory by intermediate-energy heavy-ion collisions. Theoretical methods developed for the description of multi-fragment final states in such re