April 2009 arXiv papers — page 6

Kenji Maeda, Gordon Baym, Tetsuo Hatsuda

We delineate, as an analog of two-flavor dense quark matter, the phase structure of a many-body mixture of atomic bosons and fermions in two internal states with a tunable boson-fermion attraction. The bosons b correspond to diquarks, and the fermions f to unpaired quarks. For weak b-f attraction, the system is a mixture of a Bose-Einstein condensate and deg

Akihiro Matsuzaki

We study how to measure the current structure of the process that $B$ meson decays into two unstable fermions $\bar f_a$ and $f_b$ in model independent way. We use the momentum distributions of subsequent decay products affected by $\bar f_a f_b$ spin correlation. We have found the following: (1) We can extract the absolute values of two effective coupling c

James R. Wootton, Jiannis K. Pachos

We consider topological quantum memories for a general class of abelian anyon models defined on spin lattices. These are non-universal for quantum computation when restricting to topological operations alone, such as braiding and fusion. The effects of additional non-topological operations, such as spin measurements, are studied. These are shown to allow uni

Kikuo Harigaya

Nano-carbon materials are investigated intensively. In this paper, the edge-state in nanographene materials with zigzag edges is studied theoretically. In particular, while the inter-layer interactions are considered, we prove that edge states exist at the energy of the Dirac point in the doubly stacked nanographene, and in the case of the infinitely-wide lo

Vladimir Vovk

This paper establishes a non-stochastic analogue of the celebrated result by Dubins and Schwarz about reduction of continuous martingales to Brownian motion via time change. We consider an idealized financial security with continuous price path, without making any stochastic assumptions. It is shown that typical price paths possess quadratic variation, where

Michael J. Tannenbaum

Measurements of $π^0$, identified charged hadrons, direct-single-$γ$, direct single-$e^{\pm}$ and jets are expected to be important probes of the Quark Gluon Plasma (QGP) at LHC as they are at RHIC. Recent results from RHIC will be presented, with implications, possibly grave, for LHC. Issues of soft-physics, such as $E_T$ distributions, will be discussed wi

Stefano de Capua

The LHCb experiment is dedicated to precision measurements of CP violation and rare decays of B hadrons at the Large Hadron Collider (LHC) at CERN. The LHCb installation has been finished in spring 2008 and an intensive testing and commissioning of the system has been started. An overview and the results from our commissioning activities are described.

Kingman Cheung, Otto C. W. Kong, Jae Sik Lee

We study the electric dipole moment (EDM) and the anomalous magnetic dipole moment (MDM) of the muon in the CP-violating Minimal Supersymmetric extension of the Standard Model (MSSM). We take into account the contributions from the chargino- and neutralino-mediated one-loop graphs and the dominant two-loop Higgs-mediated Barr-Zee diagrams. We improve earlier

Joachim Kopp

We demonstrate the correspondence between quantum mechanical and quantum field theoretical descriptions of Mossbauer neutrino oscillations. First, we compute the combined rate $Γ$ of Mossbauer neutrino emission, propagation, and detection in quantum field theory, treating the neutrino as an internal line of a tree level Feynman diagram. We include explicitly

Lu-Lu Wang, Xi-Feng Ren, Rui Yang, Guang-Can Guo

We experimentally investigate the extraordinary optical transmission of doughnut light through a bull's eye structure. Since the intensity is vanished in the center of the beam, almost all the energy reaches the circular corrugations (not on the hole), excite surface plasmons which propagate through the hole and reradiate photons. The transmitted energy

G. Lima, A. Vargas, L. Neves, R. Guzmán

The study of how to generate high-dimensional quantum states (qudits) is justified by the advantages that they can bring for the field of quantum information. However, to have some real practical potential for quantum communication, these states must be also of simple manipulation. Spatial qudits states, which are generated by engineering the transverse mome

O. Fialko, A. Gammal, K. Ziegler

We study attractive fermions in an optical lattice superimposed by a trapping potential, such that fermions may form bosonic molecules. We map the model onto nonlinear field equations depending on the Nambu-Gor'kov propagator. The resulting field equations where solved numerically by a relaxation technique that allowed us to calculate the inhomogeneous d

Prabhu Manyem

We show that simple syntactic expressions such as existential second order (ESO) universal Horn formulae can express NP-hard optimisation problems. There is a significant difference between the expressibilities of decision problems and optimisation problems. This is similar to the difference in computation times for the two classes of problems; for example,

Ivan Cherednik, Xiaoguang Ma

This paper is based on the lectures given by the first author at Harvard in February and March, 2009. It begins with an introduction to the classical p-adic theory of the Macdonald, Matsumoto and Whittaker functions. Its major directions are as follows: 1) extending the theory of DAHA to arbitrary levels; 2) the affine Satake isomorphism and Hall functions v

Leonardo Balart

The energy distributions for a black hole solution resulting from coupling electrodynamics and gravity in 2+1 dimensions are obtained. This solution considers the correction for a 2+1 static charged black hole from the first contribution of the weak field limit of one loop QED in 2+1 dimensions. The Einstein and Moller energy-momentum prescriptions are used

M. Bina, F. Casagrande, M. Genoni, A. Lulli

We describe the transfer of quantum information and correlations from an entangled tripartite bosonic system to three separate qubits through their local environments also in the presence of various dissipative effects. Optimal state mapping and entanglement transfer are shown in the framework of optical cavity quantum electrodynamics involving qubit-like ra

Francesco De Martini, Fabio Sciarrino, Nicolo' Spagnolo

We show that all Macroscopic Quantum Superpositions (MQS) based on phase-covariant quantum cloning are characterized by an anomalous high resilence to the de-coherence processes. The analysis supports the results of recent MQS experiments and leads to conceive a useful conjecture regarding the realization of complex decoherence - free structures for quantum

Masashi Kimura

We construct dynamical black ring solutions in the five dimensional Einstein-Maxwell system with a positive cosmological constant and investigate the geometrical structure. The solutions describe the physical process such that a thin black ring at early time shrinks and changes into a single black hole as time increase. We also discuss the multi-black rings

John Voight

We consider the class of algebras of rank 4 equipped with a standard involution over an arbitrary base ring. In particular, we characterize quaternion rings, those algebras defined by the construction of the even Clifford algebra.

G. W. Lin, X. B. Zou, X. M. Lin, G. C. Guo

We propose an efficient method to realize a large-scale one-way quantum computer in a two-dimensional (2D) array of coupled cavities, based on coherent displacements of an arbitrary state of cavity fields in a closed phase space. Due to the nontrivial geometric phase shifts accumulating only between the qubits in nearest-neighbor cavities, a large-scale 2D c

Junichi Baba, Yoshiharu Asaki, Junichiro Makino, Makoto Miyoshi

Recent VLBI (Very Long Baseline Interferometer) observations determined the distances and proper motions of star-forming regions in spiral arms directly. They showed that star-forming regions and young stars have large peculiar motions, as large as 30 km/s with complex structures. Such a large peculiar motion is incompatible with the prediction of the standa

Yumiko Hironaka

We study spherical functions on the space isomorphic to $U(2n)/(U(n)\times U(n))$ over a $p$-adic field; those functional equations with respect to the action of the Weyl group, the location of possible poles and zeros, explicit formulas, and spherical Fourier transforms. Then, as an application, we give a functional equation of $p$-adic local hermitian Sieg

Kazuyoshi Yoshimi, Takeo Kato, Hideaki Maebashi

Based on the non-skeleton diagrammatic expansion satisfying the compressibility and spin-susceptibility sum rules, we investigate static charge and spin responses in a two-dimensional extended Hubbard model with the nearest-neighbor Coulomb repulsion in the vicinity of its charge-ordering transition point. In this expansion, we can calculate approximate char

H. Mukuda, N. Terasaki, N. Tamura, H. Kinouchi

We report systematic 57Fe-NMR and 75As-NMR/NQR studies on an underdoped sample (T_c=20 K), an optimally doped sample (T_c=28 K), and an overdoped sample (T_c=22 K) of oxygen-deficient iron (Fe)-based oxypnictide superconductor LaFeAsO_{1-y}$. A microscopic phase separation between superconducting domains and magnetic domains is shown to take place in the und

Federico Piazza

The equivalence principle suggests to consider gravity as an infra-red phenomenon, whose effects are visible only outside Einstein's free-falling elevator. By curving spacetime, General Relativity leaves the smallest systems free of classical gravitational effects. However, according to the standard semi-classical treatment, indirect effects of gravity can b

James P. Gleeson

Analytical results are derived for the bond percolation threshold and the size of the giant connected component in a class of random networks with non-zero clustering. The network's degree distribution and clustering spectrum may be prescribed, and theoretical results match well to numerical simulations on both synthetic and real-world networks.

Darryl D. Holm

An optimization method used in image-processing (metamorphosis) is found to imply Euler's equations for incompressible flow of an inviscid fluid, without requiring that the Lagrangian particle labels exactly follow the flow lines of the Eulerian velocity vector field. Thus, an optimal control problem and an optimization problem for incompressible ideal f

H. Nakada, K. Mizuyama, M. Yamagami, M. Matsuo

The Gaussian expansion method (GEM) is extensively applied to the calculations in the random-phase approximation (RPA). We adopt the mass-independent basis-set that has been tested in the mean-field calculations. By comparing the RPA results with those obtained by several other available methods for Ca isotopes, using a density-dependent contact interaction

Helen Kirk, Doug Johnstone, Shantanu Basu

We analyze a suite of thin sheet magnetohydrodynamical simulations based on the formulation of Basu, Ciolek, Dapp & Wurster. These simulations allow us to examine the observational consequences to a star-forming region of varying the input level of turbulence (between thermal and a Mach number of 4) and the initial magnetic field strength corresponding to a

Andrea Casaccino, Seth Lloyd, Stefano Mancini, Simone Severini

We study quantum state transfer through a qubit network modeled by spins with XY interaction, when relying on a single excitation. We show that it is possible to achieve perfect transfer by shifting (adding) energy to specific vertices. This technique appears to be a potentially powerful tool to change, and in some cases improve, transfer capabilities of qua

Carlos Colosqui, Devrez M. Karabacak, Kamil L. Ekinci, Victor Yakhot

In this work, we employ a kinetic theory based approach to predict the hydrodynamic forces on electromechanical resonators operating in gaseous media. Using the Boltzmann-BGK equation, we investigate the influence of the resonator geometry on the fluid resistance in the entire range of nondimensional frequency variation $0\leτω\le\infty$; here the fluid rela

R. U. Abbasi, T. Abu-Zayyad, M. Al-Seady, M. Allen

The High Resolution Fly's Eye experiment has measured the flux of ultrahigh energy cosmic rays using the stereoscopic air fluorescence technique. The HiRes experiment consists of two detectors that observe cosmic ray showers via the fluorescence light they emit. HiRes data can be analyzed in monocular mode, where each detector is treated separately, or i

Kaushik Majumdar

If two signals are phase synchronous then the respective Fourier component at each spectral band should exhibit certain properties. In a pair of artificially generated phase synchronous signals the phase difference at each frequency band changes very slowly over the subsequent frequency bands. This has been called Fourier uniformity in this paper and a measu

M. L. Bedran

In the Friedmann cosmology the deceleration of the expansion q plays a fundamental role. We derive the deceleration as a function of redshift $q(z)$ in two scenarios: $Λ$ CDM model and modified Chaplygin gas (MCG) model, without assuming spatial flatness. The expression relating the transition redshift from decelerated to accelerated expansion $z_t$ to the c

Emil Y. Sidky, Chien-Min Kao, Xiaochuan Pan

In practical applications of tomographic imaging, there are often challenges for image reconstruction due to under-sampling and insufficient data. In computed tomography (CT), for example, image reconstruction from few views would enable rapid scanning with a reduced x-ray dose delivered to the patient. Limited-angle problems are also of practical significan

Eric Lauga

In many biological systems, microorganisms swim through complex polymeric fluids, and usually deform the medium at a rate faster than the inverse fluid relaxation time. We address the basic properties of such life at high Deborah number analytically by considering the small-amplitude swimming of a body in an arbitrary complex fluid. Using asymptotic analysis

Christine H. Chen

Multi-wavelength spectroscopy can be used to constrain the dust and gas properties in debris disks. Circumstellar dust absorbs and scatters incident stellar light. The scattered light is sometimes resolved spatially at visual and near-infrared wavelengths using high contrast imaging techniques that suppress light from the central star. The thermal emission i

V. S. Zapf, M. Kenzelmann, F. Wolff-Fabris, F. Balakirev

The coupling between magnetic order and ferroelectricity has been under intense investigation in a wide range of transition-metal oxides. The strongest coupling is obtained in so-called magnetically-induced multiferroics where ferroelectricity arises directly from magnetic order that breaks inversion symmetry. However, it has been difficult to find non-oxide

R. Ciftci, A. K. Ciftci

We propose some channels for the possible observation of anomalous interactions of the fourth standard model generation quarks at the Large Hadron Collider based ep and gamma-p colliders. Namely, u_4 (d_4) -> q gamma and u_4 (d_4) -> q Z -> q l^+ l^- decay processes are considered. Signatures for signals and corresponding standard model backgrounds are inves

E. Colombier, S. L. Bud'ko, N. Ni, P. C. Canfield

The temperature dependent electrical resistivity of single crystalline SrFe2As2 and BaFe2As2 has been measured in a liquid medium, modified Bridgman anvil cell for pressures in excess of 75 kbar. These data allow for the determination of the pressure dependence of the higher temperature, structural / antiferromagnetic phase transitions as well as the lower t

Maximilian Kreuzer

While Calabi-Yau hypersurfaces in toric ambient spaces provide a huge number of examples, theoretical considerations as well as applications to string phenomenology often suggest a broader perspective. With even the question of finiteness of diffeomorphism types of CY 3-folds unsettled, an important idea is Reid's conjecture that the moduli spaces are co

K. Kleidis, A. Kuiroukidis, P. Nerantzi, D. B. Papadopoulos

Under a particular choice of the Ernst potential, we solve analytically the Einstein-Maxwell equations to derive a new exact solution depending on five parameters: the mass, the angular-momentum (per unit mass), the electromagnetic-field strength, k, the parameter-p and the Kerr-NUT parameter, l. This (Petrov Type D) solution is cylindrically-symmetric and r

Olga Kharlampovich, Alexei Myasnikov

This paper represents notes of the mini-courses given by the authors at the GCGTA conference in Dortmund (2007), Ottawa-Saint Sauveur conference (2007), Escola d'Algebra in Rio de Janeiro (2008) and Alagna (Italy, 2008) conference on equations in groups. We explain here the Elimination process for solving equations in a free group which has Makanin-Razbo

X. Chen, P. Madau, A. Sesana, F. K. Liu

"Hard" massive black hole (MBH) binaries embedded in steep stellar cusps can shrink via three-body slingshot interactions. We show that this process will inevitably be accompanied by a burst of stellar tidal disruptions, at a rate that can be several orders of magnitude larger than that appropriate for a single MBH. Our numerical scattering experiments revea

J. -S. Huang, S. M. Faber, E. Daddi, E. S. Laird

We analyze a sample of galaxies chosen to have F24>0.5 mJy and satisfy a certain IRAC color criterion. IRS spectra yield redshifts, spectral types, and PAH luminosities, to which we add multi-wavelength broadband photometry. Stellar population modeling and IRS spectra together demonstrate that the double criteria used to select this sample have efficiently i

Dipak Munshi, Alan Heavens

We address the dual challenge of estimating deviations from Gaussianity arising in models of the Early Universe, whilst retaining information necessary to assess whether a detection of non-Gaussianity is primordial. We do this by constructing a new statistic, the bispectrum-related power spectrum, which is constructed from a map of the Cosmic Microwave Backg

Max A. Metlitski, Carlos A. Fuertes, Subir Sachdev

It is generally believed that in spatial dimension d > 1 the leading contribution to the entanglement entropy S = - tr rho_A log rho_A scales as the area of the boundary of subsystem A. The coefficient of this "area law" is non-universal. However, in the neighbourhood of a quantum critical point S is believed to possess subleading universal correctio

Jan Pflamm-Altenburg, Pavel Kroupa

We explore the gravitational influence of pressure supported stellar systems on the internal density distribution of a gaseous environment. We conclude that compact massive star clusters with masses >= 10^6 M_sun act as cloud condensation nuclei and are able to accrete gas recurrently from a warm interstellar medium which may cause further star formation eve

Derek A. Stewart

Experimental studies of FeCoB/MgO/FeCoB tunnel junctions indicate that boron diffuses into MgO during rf-sputtering and forms polycrystalline Mg-B-O regions. These tunnel junctions provide high tunneling magnetoresistance values and low RA products. However the crystal structure of the Mg-B-O region remains unknown. Using density functional techniques, I exa

G. X. Miao, J. S. Moodera

In double spin filter (SF) tunnel junctions, the spin information is generated and analyzed purely from the SF effect with nonmagnetic electrodes. In this article we numerically evaluate the bias dependence of magnetoresistance in such tunnel junctions (nonmagnetic metal / SF / nonmagnetic insulator / SF / nonmagnetic metal), particularly in cases when diffe

Maximilian Kreuzer

On the sad occasion of contributing to the memorial volume ``Fundamental Interactions'' for my teacher Wolfgang Kummer I decided to recollect and extend some unpublished notes from the mid 90s when I started to build up a string theory group in Vienna under Wolfgang as head of the particle physics group. His extremely supportive attitude was best exp

Edouard J. Bernard, Matteo Monelli, Carme Gallart, Igor Drozdovsky

(abridged) We present the first study of the variable star populations in the isolated dwarf spheroidal galaxies (dSph) Cetus and Tucana. Based on Hubble Space Telescope images obtained with the Advanced Camera for Surveys in the F475W and F814W bands, we identified 180 and 371 variables in Cetus and Tucana, respectively. The vast majority are RR Lyrae stars

Ezequiel R. Soulé, Alejandro D. Rey

We present theory and simulation of simultaneous chemical demixing and phase ordering in a polymer-liquid crystal mixture in conditions where isotropic- isotropic phase separation is metastable with respect to isotropic-nematic phase transition. It is found that mesophase formation proceeds by a transient metastable phase that surround the ordered phase, and

Juhi Jang, Ning Jiang

We study the acoustic limit from the Boltzmann equation in the framework of classical solutions. For a solution $F_\varepsilon=μ+\varepsilon \sqrtμf_\varepsilon$ to the rescaled Boltzmann equation in the acoustic time scaling \partial_t F_\varepsilon +\vgrad F_\varepsilon =\frac{1}{\varepsilon} \Q(F_\varepsilon,F_\varepsilon), inside a periodic box $\mathbb{

George B. Shabat, Alexei Sleptsov

We classify projective plane nonsingular curves admitting a 3-term presentation; they exist in any degree, generally constitute 5 birational families and are defined over rational numbers. The Belyi functions on all these curves are presented.

N. Franco

We present a survey of the application of Cones' Non-Commutative Geometry to gravitation. Bases of the theory and Euclidian gravity models are reviewed. Then we discuss the problem of a Lorentzian generalization of the theory and review existing attempts of solution.

M. Garcia, A. Herrero, B. Vicente, N. Castro

Context: Determining the parameters of massive stars is crucial to understand many processes in galaxies and the Universe, since these objects are important sources of ionization, chemical enrichment and momentum. 10m class telescopes enable us to perform detailed quantitative spectroscopic analyses of massive stars in other galaxies, sampling areas of diffe

Nelson Pinto-Neto

It is generally believed that one cannot obtain a large Universe from quantum cosmological models without an inflationary phase in the classical expanding era because the typical size of the Universe after leaving the quantum regime should be around the Planck length, and the standard decelerated classical expansion after that is not sufficient to enlarge th

M. Zaccanti, B. Deissler, C. D'Errico, M. Fattori

In 1970 V. Efimov predicted a puzzling quantum-mechanical effect that is still of great interest today. He found that three particles subjected to a resonant pairwise interaction can join into an infinite number of loosely bound states even though each particle pair cannot bind. Interestingly, the properties of these aggregates, such as the peculiar geometri

Biddut K. Sarker, M. Arif, Paul Stokes, Saiful I. Khondaker

We investigated the mechanism for photoconduction in multi-walled carbon nanotube (MWNT) film of various electrode separations upon near infrared illumination. In addition to observing strong dependence of photocurrent on the position of the laser spot, we found that the time constant of the dynamic photoresponse is slow and increases with increasing electro

Ernest Ma

If the canonical seesaw mechanism alone is responsible for neutrino mass, i.e. m_nu = -m_D^2/m_N, it can neither be proved nor disproved at the TeV energy scale. A new verifiable mechanism of neutrino mass is proposed, using the "inverse" seesaw, with new physics at the TeV scale, such that m_nu = m_D^2 epsilon_L/m_N^2, where epsilon_L is a two-loop

Lukas Kencl, Martin Loebl

Protection of the sensitive content is crucial for extensive information sharing. We present a technique of information concealing, based on introduction and maintenance of families of repeats. Repeats in DNA constitute a basic obstacle for its reconstruction by hybridization.

M. Haywood

The correlation between stellar metallicity and the presence of giant planets is well established. It has been tentatively explained by the possible increase of planet formation probability in stellar disks with enhanced amount of metals. However, there are two caveats to this explanation. First, giant stars with planets do not show a metallicity distributio

R. Cerna, D. Sarchi, T. K. Paraiso, G. Nardin

Polaritons in semiconductor microcavities are hybrid quasiparticles consisting of a superposition of photons and excitons. Due to the photon component, polaritons are characterized by a quantum coherence length in the several micron range. Owing to their exciton content, they display sizeable interactions, both mutual and with other electronic degrees of fre

O. Cata, M. Golterman, S. Peris

Duality Violations (DVs) is a nickname for the failure of the Operator Product Expansion to describe QCD correlators on the physical axis. Using a physically motivated ansatz, a fit to the spectral functions allows us to get a quantitative estimate for the amount of DVs present in tau data. The quality of the fit turns out to be better than expected. Since D

Murat M. Kaskulov, Ulrich Mosel

Deeply virtual electroproduction of pion in exclusive reaction $p(e,e'π^+)n$ is studied using a two-component model which includes soft hadronic and hard partonic reaction mechanisms. The results are compared with the experimental data measured at HERMES in the deep inelastic region for values of $Q^2>1$ GeV$^2$ and $W^2 > 10$ GeV$^2$. At forward angles

Erich Novak, Henryk Wozniakowski

This is an open letter that we sent to S. Ilie, G. Soederlind and R.M. Corless in August 2008.

H. Cao, A. Gukasov, I. Mirebeau, P. Bonville

We studied the field induced magnetic order in R$_{2}$Ti$_{2}$O$_7$ pyrochlore compounds with either uniaxial (R=Ho, Tb) or planar (R=Er, Yb) anisotropy, by polarized neutron diffraction. The determination of the local susceptibility tensor \{$χ_\parallel,χ_\perp$\} provides a universal description of the field induced structures in the paramagnetic phase (2

A. Ibort, V. I. Man'ko, G. Marmo, A. Simoni

Starting from the famous Pauli problem on the possibility to associate quantum states with probabilities, the formulation of quantum mechanics in which quantum states are described by fair probability distributions (tomograms, i.e. tomographic probabilities) is reviewed in a pedagogical style. The relation between the quantum state description and the classi

J. C. Li

According to Moore law, the silicon semiconductor transistor based information system is facing its physical limitations due to fluctuations of random charge and leakage current. Molecular electronics is becoming more and more attractive owing to the advantages of easy molecular structure variability, flexibility, low-cost and compatibility with bioelectroni

T. Schnabel, J. Vrabec, H. Hasse

The influence of the unlike Lennard-Jones (LJ) parameters on vapor-liquid equilibria of mixtures is investigated and the performance of eleven combining rules is assessed. In the first part of the work, the influence of the unlike LJ size and energy parameter on vapor pressure, bubble density and dew point composition is systematically studied for the mixtur

Maksim D. Tomchenko

The state of the superfluid He-II theory is briefly surveyed - some aspects of its history, achievements, and unsolved problems.

David Pekker, Nayana Shah, Mitrabhanu Sahu, Alexey Bezryadin

Superconducting nanowires fabricated via carbon-nanotube-templating can be used to realize and study quasi-one-dimensional superconductors. However, measurement of the linear resistance of these nanowires have been inconclusive in determining the low-temperature behavior of phase-slip fluctuations, both quantal and thermal. Thus, we are motivated to study th

Henriette Elvang, Brian Wecht

We analyze a model of Semi-Direct Gauge Mediation in which the hidden sector is the 4-1 model and the messenger fields are charged under the U(1) gauge group. At tree level, the SUSY-breaking F-terms induce D-terms from which SUSY-split messenger masses arise. We calculate these masses by three complementary methods. Additionally, we compute the one-loop cor

Xue-GUang Zhang, Deborah Dultzin, Ting-Gui Wang, Guinevere Kaufmann

We present a new model to explain the appearance of red/blue-shifted broad low-ionization emission lines, especially emission lines in optical band, which is commonly considered as an indicator of radial motion of the line emitting gas in broad emission line regions (BLRs) of Active Galactic Nuclei (AGN). We show that partly obscured disk-like BLRs of dbp em

Kei Saitou, Masahiro Tsujimoto, Ken Ebisawa, Manabu Ishida

We report the results of the Suzaku X-ray observation of XSS J12270-4859, one of the hard X-ray sources in the INTEGRAL catalogue. The object has been classified as an intermediate polar (IP) by optical spectra and a putative X-ray period of ~860 s. With a 30 ks exposure of Suzaku, we obtained a well-exposed spectrum in the 0.2-70 keV band. We conclude again

Elena Agliari, Raffaella Burioni, Davide Cassi, Franco Maria Neri

An important assumption lying behind innovation diffusion models and word-of-mouth processes is that of homogeneous mixing: at any time, the individuals making up the market are uniformly distributed in space. When the geographical parameters of the market, such as its area extension, become important, the movement of individuals must be explicitly taken int

S. A. Lusceac, C. R. Herbers, M. Vogel

2H NMR spin-lattice relaxation and line-shape analyses are performed to study the temperature-dependent dynamics of water in the hydration shells of myoglobin, elastin, and collagen.

G. Domokos, A. Á. Sipos, Gy. M. Szabó, P. L. Várkonyi

While the number of asteroids with known shapes has drastically increased over the past few years, little is known on the the time-evolution of shapes and the underlying physical processes. Here we propose an averaged abrasion model based on micro-collisons, accounting for asteroids not necessarily evolving toward regular spheroids, rather (depending on the

VERITAS Collaboration, V. A. Acciari, E. Aliu, T. Arlen

We present results from a long-term monitoring campaign on the TeV binary LSI +61 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between September 2006 and February 2008. The binary was observed by VERITAS to be variable, with all integrated observations resulting in

Yu. I. Davydov, R. Openshaw

The transition from a proportional to a self quenching streamer mode, as a function of track length and angle, was investigated in a single wire chamber filled with either pure DME or isobutane. The chamber was irradiated with $^{241}$Am alpha particles. An investigation of multistreamer events in DME due to alpha particles entering the chamber at 20$^\circ$

A. R. Yeates, D. H. Mackay

Loss of equilibrium of magnetic flux ropes is a leading candidate for the origin of solar coronal mass ejections (CMEs). The aim of this paper is to explore to what extent this mechanism can account for the initiation of CMEs in the global context. A simplified MHD model for the global coronal magnetic field evolution in response to flux emergence and sheari

Bernd Bruegmann

The success of the moving puncture method for the numerical simulation of black hole systems can be partially explained by the properties of stationary solutions of the 1+log coordinate condition. We compute stationary 1+log slices of the Schwarzschild spacetime in isotropic coordinates in order to investigate the coordinate singularity that the numerical me

Yongping Zhang, Zhaoxin Liang, Biao Wu

We comprehensively investigate gap solitons and Bloch waves in one-dimensional nonlinear periodic systems. Our results show that there exists a composition relation between them: Bloch waves at either the center or edge of the Brillouin zone are infinite chains composed of fundamental gap solitons(FGSs). We argue that such a relation is related to the exact

Nicole Kraemer

I briefly report on some unexpected results that I obtained when optimizing the model parameters of the Lasso. In simulations with varying observations-to-variables ratio n=p, I typically observe a strong peak in the test error curve at the transition point n/p = 1. This peaking phenomenon is well-documented in scenarios that involve the inversion of the sam

Angélica Osorno

Ganter and Kapranov associated a 2-character to 2-representations of a finite group. Elgueta classified 2-representations in the category of 2-vector spaces 2Vect_k in terms of cohomological data. We give an explicit formula for the 2-character in terms of this cohomological data and derive some consequences.

Abdallah Assi

We give a criterion for a quasi-ordinary polynomial to be irreducible. The criterion is based on the notion of approximate roots and that of generalized Newton polygons.

Anne Canteaut, Maria Naya-Plasencia

A divide-and-conquer cryptanalysis can often be mounted against some keystream generators composed of several (nonlinear) independent devices combined by a Boolean function. In particular, any parity-check relation derived from the periods of some constituent sequences usually leads to a distinguishing attack whose complexity is determined by the bias of the

Jean-Philippe Auzelle, Olivier Nartz, Jean-Yves Bron

Through its projects, the ?Atelier Inter-établissements de Productique Lorrain? (AIPL), as the owner and contractor of rank 1, is committed to provide his customers (teachers, training courses, students etc...) credible teaching materials at the scale of a real industrial flexible production of goods and services. In this changing context, its managerial tea

I. G. Roseboom, S. Oliver, D. Farrah

We have performed IRS low resolution 5-12 micron spectroscopy on a sample of galaxies selected to be at 3 distinct post-starburst evolutionary stages based on their optical spectral indices. The resulting IRS spectra show distinctive PAH emission line structures at 6.2, 7.7, 8.6 and 11.3 micron and little silicate absorption, indicative of ongoing star forma

Oliver Bar, Silvia Necco, Stefan Schaefer

We study the impact of explicit chiral symmetry breaking of lattice Wilson fermions on mesonic correlators in the epsilon-regime using Wilson chiral perturbation theory. We generalize the epsilon-expansion of continuum chiral perturbation theory to nonzero lattice spacing a and distinguish various regimes. It turnes out that lattice corrections are highly su

C. L. Herzenberg

An improved criterion for distinguishing conditions in which classical or quantum behavior occurs is developed by comparing classical and quantum mechanical measures of size while incorporating spatial and temporal restrictions on wave packet formation associated with limitations on spatial extent and duration.

D. Nuzhnyy, J. Petzelt, S. Kamba, T. Yamada

Several SrTiO3 (STO) thin films without electrodes processed by pulsed laser deposition, of thicknesses down to 40 nm, were studied using infrared transmission and reflection spectroscopy. The complex dielectric responses of polar phonon modes, particularly ferroelectric soft mode, in the films were determined quantitatively. The compressed epitaxial STO fil

L. Brey, H. A. Fertig

We analyze the range of validity of Thomas Fermi theory for describing charge density modulations induced by external potentials in neutral graphene. We compare exact results obtained from a tight-binding calculation with those of linear response theory and the Thomas Fermi approximation. For experimentally interesting ranges of size and density amplitudes (

U. Atxitia, O. Chubykalo-Fesenko, J. Walowski, A. Mann

We compare femtosecond pump-probe experiments in Ni and micromagnetic modelling based on the Landau-Lifshitz-Bloch equation coupled to a two-temperature model, revealing a predominant thermal ultrafast demagnetization mechanism. We show that both spin (femtosecond demagnetization) and electron-phonon (magnetization recovery) rates in Ni increase as a functio

A. A. Vidotto, M. Opher, V. Jatenco-Pereira, T. I. Gombosi

By means of self-consistent 3D MHD numerical simulations, we analyze magnetized solar-like stellar winds and their dependence on the plasma-beta parameter. We adopt in our simulations a heating parameter described by gamma, which is responsible for the thermal acceleration of the wind. We analyze winds with polar magnetic field intensities ranging from 1 to

Felix Schmitt, Markus Hild, Robert Roth

We study the zero-temperature phase diagram of a gas of bosonic 87-Rb atoms in two-color superlattice potentials starting directly from the experimental parameters, such as wavelengths and intensities of the two lasers generating the superlattice. In a first step, we map the experimental setup to a Bose-Hubbard Hamiltonian with site-dependent parameters thro

M. Ya. Amusia

Hartree-Fock atom in a strong electric static field is considered. It is demonstrated that exchange between outer and inner electrons, taken into account by the so-called Fock term affects strongly the long-range behavior of the inner electron wave function. As a result, it dramatically increases its probability to be ionized. A simple model is analyzed demo

Peter Kalmus

We present the results of a LIGO search for short-duration gravitational waves (GW) associated with soft gamma repeater (SGR) bursts. This is the first GW search sensitive to neutron star f-modes, usually considered the most efficient GW emitting modes. We find no evidence of GWs associated with any SGR burst in a sample consisting of the 2004 December 27 gi

Christian Bonatti, Ming Li, Dawei Yang

On every compact 3-manifold, we build a non-empty open set $\cU$ of $\Diff^1(M)$ such that, for every $r\geq 1$, every $C^r$-generic diffeomorphism $f\in\cU\cap \Diff^r(M)$ has no topological attractors. On higher dimensional manifolds, one may require that $f$ has neither topological attractors nor topological repellers. Our examples have finitely many quas