January 2010 arXiv papers — page 48
Showing 4,701–4,800 of 5,448 papers
Philip G. Judge
I argue that one should attempt to understand the solar chromosphere not only for its own sake, but also if one is interested in the physics of: the corona; astrophysical dynamos; space weather; partially ionized plasmas; heliospheric UV radiation; the transition region. I outline curious observations which I personally find puzzling and deserving of attenti
Optical analogue of population trapping in the continuum: classical and quantum interference effects
quant-phS. Longhi
A quantum theory of light propagation in two optical channel waveguides tunnelling-coupled to a common continuum of modes (such as those of a slab waveguide) is presented, and classical and quantum interference effects are investigated. For classical light, the photonic system realizes an optical analogue of coherent population trapping in the continuum enco
Xincheng Xie, Xuele Liu
We study the spin Nernst effect of a mesoscopic four-terminal cross-bar device with the Rashba spin-orbit interaction (SOI) in the absence of a magnetic field. The interplay between the spin Nernst effect and the seebeck coefficient is investigated for a wide range of the Rashba SOI. When no peaks appeared in the seebeck coefficient, an oscillatory spin Nern
S. Longhi
General properties of linear propagation of discretized light in homogeneous and curved waveguide arrays are comprehensively investigated and compared to those of paraxial diffraction in continuous media. In particular, general laws describing beam spreading, beam decay and discrete far-field patterns in homogeneous arrays are derived using the method of mom
Boundary conditions and the critical Casimir force on an Ising model film: exact results in one and two dimensions
cond-mat.stat-mechRoya Zandi, Joseph Rudnick, Aviva Shackell, Douglas Abraham
Finite size effect in critical systems can be interpreted as universal Casimir forces. Here we compare the Casimir force for free, periodic and antiperiodic boundary conditions in the exactly calculable case of the Ising model in one and two dimensions. We employ a new procedure which allows us to calculate the Casimir force with periodic and antiperiodic bo
S. Longhi
An 'optical ratchet' for discretized light in photonic lattices, which enables to observe rectification of light refraction at any input beam conditions, is theoretically presented, and a possible experimental implementation based on periodically-curved zigzag waveguide arrays is proposed.
Beverly J. Smith, Mark L. Giroux, Curtis Struck, Mark Hancock
We have used the GALEX ultraviolet telescope to study stellar populations and star formation morphology in a well-defined sample of 42 nearby optically-selected pre-merger interacting galaxy pairs. Galaxy interactions were likely far more common in the early Universe than in the present, thus our study provides a nearby well-resolved comparison sample for hi
S. Longhi
Bloch oscillations (BOs) of polychromatic beams in circularly-curved optical waveguide arrays are smeared out owing to the dependence of the BO spatial period on wavelength. Here it is shown that restoring of the self-imaging property of the array and approximate BOs over relatively broad spectral ranges can be achieved by insertion of suitable lumped phase
S. Longhi
Classical and quantum interference of light propagating in arrays of coupled waveguides and undergoing multiband optical Bloch oscillations (BOs) with negligible Zener tunneling is theoretically investigated. In particular, it is shown that Mach-Zehnder-like interference effects spontaneously arise in multiband BOs owing to beam splitting and subsequent beam
Nathan Geer, Jonathan Kujawa, Bertrand Patureau-Mirand
In this paper we use topological techniques to construct generalized trace and modified dimension functions on ideals in certain ribbon categories. Examples of such ribbon categories naturally arise in representation theory where the usual trace and dimension functions are zero, but these generalized trace and modified dimension functions are non-zero. Such
S. Longhi
Optical analogues of coherent vibrational phenomena in molecules, such as light-induced molecular stabilization and wave packet dynamics at a potential crossing, are proposed for light beams in coupled slab waveguides.
Ian Dobbs-Dixon, Andrew Cumming, D. N. C Lin
We present a new approach for simulating the atmospheric dynamics of the close-in giant planet HD209458b that allows for the decoupling of radiative and thermal energies, direct stellar heating of the interior, and the solution of the full 3D Navier Stokes equations. Simulations reveal two distinct temperature inversions (increasing temperature with decreasi
S. Longhi
Bloch oscillations (BO) in complex lattices with PT symmetry are theoretically investigated with specific reference to optical BO in photonic lattices with gain/loss regions. Novel dynamical phenomena with no counterpart in ordinary lattices, such as non-reciprocal BO related to violation of the Friedel's law of Bragg scattering in complex potentials, ar
Diffuse far-infrared and ultraviolet emission in the NGC4435/4438 system: tidal stream or Galactic cirrus?
astro-ph.COL. Cortese, G. J. Bendo, K. G. Isaak, J. I. Davies
We report the discovery of diffuse far-infrared and far-ultraviolet emission projected near the interacting pair NGC4435/4438, in the Virgo cluster. This feature spatially coincides with a well known low surface-brightness optical plume, usually interpreted as tidal debris. If extragalactic, this stream would represent not only one of the clearest examples o
The Mass-Metallicity Relation of Globular Clusters in the Context of Nonlinear Color-Metallicty Relations
astro-ph.COJohn P. Blakeslee, Michele Cantiello, Eric W. Peng
Two recent empirical developments in the study of extragalactic globular cluster (GC) populations are the color-magnitude relation of the blue GCs (the "blue tilt") and the nonlinearity of the dependence of optical GC colors on metallicity. The color-magnitude relation, interpreted as a mass-metallicity relation, is thought to be a consequence of self-enrich
D. Witthaut, A. S. Sorensen
We discuss the scattering of photons from a three-level emitter in a one-dimensional waveguide, where the transport is governed by the interference of spontaneously emitted and directly transmitted waves. The scattering problem is solved in closed form for different level structures. Several possible applications are discussed: The state of the emitter can b
S. Longhi
The behavior of a Bloch particle in a complex crystal with PT symmetry subjected to a sinusoidal ac force is theoretically investigated. For unbroken PT symmetry and in the single-band approximation, it is shown that time reversal symmetry of the ac force preserves the reality of the quasienergy spectrum. Like in ordinary crystals, exact band collapse, corre
R. Machleidt, D. R. Entem
In spite of the great progress we have seen in recent years in the derivation of nuclear forces from chiral effective field theory (EFT), some important issues are still unresolved. In this contribution, we discuss the open problems which have particular relevance for microscopic nuclear structure, namely, the proper renormalization of chiral nuclear potenti
S. Longhi
Spectral singularities are predicted to occur in a non-Hermitian extension of the Friedrichs-Fano-Anderson model describing the decay of a discrete state $|a >$ coupled to a continuum of modes. A physical realization of the model, based on electronic or photonic transport in a semi-infinite tight-binding lattice with an imaginary impurity site at the lattice
Proximity effect and electron transport in the oxide hybrid heterostructures with superconducting/magnetic interfaces
cond-mat.supr-conG. A. Ovsyannikov, K. Y. Constantinian, Yu. V. Kislinski, A. V. Shadrin
We report on the study of electron transport in the oxide heterostructures with superconductor/magnetic matter (S/M) interfaces where anomaly large penetration of superconducting correlations in magnetic matter (proximity effect) is realized. The developed theoretical model based on multilayer magnetic structure of M-interlayer and experiment show presence o
S. Longhi
Spectral singularities that spoil the completeness of Bloch-Floquet states may occur in non-Hermitian Hamiltonians with complex periodic potentials. Here an equivalence is established between spectral singularities in complex crystals and secularities that arise in Bragg diffraction patterns. Signatures of spectral singularities in a scattering process with
Michael J. Neely
We extend stochastic network optimization theory to treat networks with arbitrary sample paths for arrivals, channels, and mobility. The network can experience unexpected link or node failures, traffic bursts, and topology changes, and there are no probabilistic assumptions describing these time varying events. Performance of our scheduling algorithm is comp
Leptonic/hadronic models for electromagnetic emission in microquasars: the case of GX 339-4
astro-ph.HEGabriela S. Vila, Gustavo E. Romero
We present a general self-consistent lepto/hadronic jet model for the non-thermal electromagnetic emission of microquasars. The model is applied to the low-mass microquasar (LMMQ) GX 339-4 and predicts its high-energy features. We assume that both leptons and hadrons are accelerated up to relativistic energies by diffusive shock acceleration, and calculate t
Effectively integrating information content and structural relationship to improve the GO-based similarity measure between proteins
cs.CEBo Li, James Z. Wang, F. Alex Feltus, Jizhong Zhou
The Gene Ontology (GO) provides a knowledge base to effectively describe proteins. However, measuring similarity between proteins based on GO remains a challenge. In this paper, we propose a new similarity measure, information coefficient similarity measure (SimIC), to effectively integrate both the information content (IC) of GO terms and the structural inf
BCS-BEC model of high-Tc superconductivity in layered cuprates with unconventional pairing
cond-mat.supr-conC. Villarreal, M. de Llano
High-Tc superconductivity in layered cuprates is described in a BCS-BEC formalism with linearly-dispersive s- and d-wave Cooper pairs moving in quasi-2D finite-width layers about the CuO_2 planes. This yields a closed formula for Tc determined by the layer width, the Debye frequency, the pairing energy, and the in-plane penetration depth. The new formula rea
An Accelerometer Based Instrumentation of the Golf Club: Measurement and Signal Analysis
physics.ins-detRobert D. Grober
Two accelerometers are used to measure the motion of the golf club. The accelerometers are mounted in the shaft of the golf club. Each measures the acceleration along the axis of the shaft of the golf club. Interpreting the measurement with the context of the double pendulum model of the golf swing, it is useful to resolve the resulting signals into differen
Gary L. Case, Michael L. Cherry, James Rodi, Ascencion Camero-Arranz
The NaI and BGO detectors on the Gamma ray Burst Monitor (GBM) on Fermi are now being used for long term monitoring of the hard X-ray/low energy gamma ray sky. Using the Earth occultation technique demonstrated previously by the BATSE instrument on the Compton Gamma Ray Observatory, GBM produces multiband light curves and spectra for known sources and transi
From quantum feedback to probabilistic error correction: Manipulation of quantum beats in cavity QED
quant-phP. Barberis-Blostein, D. G. Norris, L. A. Orozco, H. J. Carmichael
It is shown how to implement quantum feedback and probabilistic error correction in an open quantum system consisting of a single atom, with ground- and excited-state Zeeman structure, in a driven two-mode optical cavity. The ground state superposition is manipulated and controlled through conditional measurements and external fields, which shield the cohere
Zdenka Riecanova
We study Archimedean atomic lattice effect algebras whose set of sharp elements is a complete lattice. We show properties of centers, compatibility centers and central atoms of such lattice effect algebras. Moreover, we prove that if such effect algebra $E$ is separable and modular then there exists a faithful state on $E$. Further, if an atomic lattice effe
Leonardo Colzani, Giacomo Gigante, Giancarlo Travaglini
There exists a positive function $ψ(t)${on}$t\geq0${, with fast decay at infinity, such that for every measurable set}$Ω${in the Euclidean space and}$R>0${, there exist entire functions}$A(x) ${and}$B(x) ${of exponential type}$R${, satisfying\}$A(x)\leq χ_Ω(x)\leq B(x)${and}$| B(x)-A(x)| \leqslantψ(R\operatorname*{dist}(x,\partialΩ)) $. This leads to Erdős T
Alicia Dickenstein, Mercedes Perez Millan
The aim of this article is to build on the use of tools from computational algebra initiated in Craciun, Dickenstein, Shiu, Sturmfels (JSC, 2009), for the study of general kinetic systems, which have a wide range of applications in chemistry and biology. We clarify the relation between the algebraic conditions that must be satisfied by the reaction constants
Fock quantization of a scalar field with time dependent mass on the three-sphere: unitarity and uniqueness
gr-qcJeronimo Cortez, Guillermo A. Mena Marugan, Jose M. Velhinho
We study the Fock description of a quantum free field on the three-sphere with a mass that depends explicitly on time, also interpretable as an explicitly time dependent quadratic potential. We show that, under quite mild restrictions on the time dependence of the mass, the specific Fock representation of the canonical commutation relations which is naturall
C. Thiemann, F. Theis, D. Grady, R. Brune
Geographic borders are not only essential for the effective functioning of government, the distribution of administrative responsibilities and the allocation of public resources, they also influence the interregional flow of information, cross-border trade operations, the diffusion of innovation and technology, and the spatial spread of infectious diseases.
Chulwoo Jung
I give an overview of current and future plans of dynamical QCD ensemble generation activities. A comparison of simulation cost between different discretizations is made. Recent developments in techniques and algorithms used in QCD dynamical simulations, especially mass reweighting, are also discussed.
Erratum: Dirichlet Forms and Dirichlet Operators for Infinite Particle Systems: Essential Self-adjointness
math-phVeni Choi, Yong Moon Park, Hyun Jae Yoo
We reprove the essential self-adjointness of the Dirichlet operators of Dirchlet forms for infinite particle systems with superstable and sub-exponentially decreasing interactions.
Victor Vuletescu
For elliptic principal bundles $π:X\ra B$ over Kähler manifolds it was shown by Blanchard that $X$ has a Kähler metric if and only both Chern classes (with real coefficients) of $π$ vanish. For some elliptic principal bundles, when the span of these Chern classes is 1-dimensional, it was shown by Vaisman that $X$ carry locally conformally Kähler (LCK, for sh
Clint Young, Kevin Dusling
Quarkonium at temperatures above deconfinement is modeled as an open quantum system, whose dynamics is determined not just by a potential energy and mass, but also by a drag coefficient which characterizes its interaction with the medium. The reduced density matrix for a heavy particle experiencing dissipative forces is expressed as an integral over paths in
Z. L. Yuan, A. W. Sharpe, J. F. Dynes, A. R. Dixon
We report a 2 GHz operation of InGaAs avalanche photodiodes for efficient single photon detection at telecom wavelengths. Employing a self-differencing circuit that incorporates tuneability in both frequency and arm balancing, extremely weak avalanches can now be sensed so as to suppress afterpulsing. The afterpulse probability is characterized as 4.84% and
Fahd Jarad, Octavian G. Mustafa, Donal O'Regan
We discuss the occurrence of positive solutions which decay to 0 as $| x|\to+\infty$ to the differential equation $Δu+f(x,u)+g(| x|)x\cdot\nabla u=0$, $| x|>R>0$, $x\in\mathbb{R}^{n}$, where $n\geq 3$, $g$ is nonnegative valued and $f$ has alternating sign, by means of the comparison method. Our results complement several recent contributions from [M. Ehrnst
Octavian G. Mustafa
We discuss the occurrence of oscillatory solutions which decay to 0 as $s\to+\infty$ for a class of perturbed second order ordinary differential equations. As opposed to other results in the recent literature, the perturbation is as small as desired in terms of its improper integrals and it is independent of the coefficients of the non-oscillatory unperturbe
L. Gizon, A. C. Birch, H. C. Spruit
The Sun supports a rich spectrum of internal waves that are continuously excited by turbulent convection. The GONG network and the MDI/SOHO space instrument provide an exceptional data base of spatially-resolved observations of solar oscillations, covering an entire sunspot cycle (11 years). Local helioseismology is a set of tools for probing the solar inter
S. Van Loo, S. A. E. G. Falle, T. W. Hartquist, O. Havnes
Star formation occurs in dark molecular regions where the number density of hydrogen nuclei, nH, exceeds 10^4 cc and the fractional ionization is 10^-7 or less. Dust grains with sizes ranging up to tenths of microns and perhaps down to tens of nanometers contain just under one percent of the mass. Recombination on grains is important for the removal of gas p
Brijnesh J. Jain, Klaus Obermayer
Vector quantization(VQ) is a lossy data compression technique from signal processing for which simple competitive learning is one standard method to quantize patterns from the input space. Extending competitive learning VQ to the domain of graphs results in competitive learning for quantizing input graphs. In this contribution, we propose an accelerated vers
C. H. Jeffrey Pang
For a real valued function, a point is critical if its derivatives are zero, and a critical point is a saddle point if it is not a local extrema. In this paper, we study algorithms to find saddle points of general Morse index. Our approach is motivated by the multidimensional mountain pass theorem, and extends our earlier work on methods (based on studying t
Bridging length and time scales in sheared demixing systems: from the Cahn-Hilliard to the Doi-Ohta model
cond-mat.stat-mechAsja Jelic, Patrick Ilg, Hans Christian Öttinger
We develop a systematic coarse-graining procedure which establishes the connection between models of mixtures of immiscible fluids at different length and time scales. We start from the Cahn-Hilliard model of spinodal decomposition in a binary fluid mixture under flow from which we derive the coarse-grained description. The crucial step in this procedure is
Particle Swarm Optimization and gravitational wave data analysis: Performance on a binary inspiral testbed
gr-qcYan Wang, Soumya D. Mohanty
The detection and estimation of gravitational wave (GW) signals belonging to a parameterized family of waveforms requires, in general, the numerical maximization of a data-dependent function of the signal parameters. Due to noise in the data, the function to be maximized is often highly multi-modal with numerous local maxima. Searching for the global maximum
Chaz Schlindwein
This is an exposition of much of Sections VI.3 and XVIII.3 of "Proper and Improper Forcing", including preservations for "no random reals over V", "reals of V form a non-meager set", "every dense open set contains a dense open set in V", weak bounding, and weak $ω^ω$-bounding. The current version of part I covering Sections VI
Brijnesh J. Jain, Klaus Obermayer
Vector quantization(VQ) is a lossy data compression technique from signal processing, which is restricted to feature vectors and therefore inapplicable for combinatorial structures. This contribution presents a theoretical foundation of graph quantization (GQ) that extends VQ to the domain of attributed graphs. We present the necessary Lloyd-Max conditions f
Martin Olbermann
In this article, we classify all involutions on S^6 with 3-dimensional fixed point set. In particular, we discuss the relation between the classification of involutions with fixed point set a knotted 3-sphere and the classification of free involutions on homotopy CP^3's.
S. A. Klioner, E. Gerlach, M. H. Soffel
Relativistic modelling of rotational motion of extended bodies represents one of the most complicated problems of Applied Relativity. The relativistic reference systems of IAU (2000) give a suitable theoretical framework for such a modelling. Recent developments in the post-Newtonian theory of Earth rotation in the limit of rigidly rotating multipoles are re
David G. Koch, William J. Borucki, Jason F. Rowe, Natalie M. Batalha
We present 44 days of high duty cycle, ultra precise photometry of the 13th magnitude star Kepler-5 (KIC 8191672, Teff=6300 K, logg=4.1), which exhibits periodic transits with a depth of 0.7%. Detailed modeling of the transit is consistent with a planetary companion with an orbital period of 3.548460+/-0.000032 days and a radius of 1.431+/-0.050 Rj. Follow-u
Brandon Carter
This article continues the study of the category of harmonious field models that was recently introduced as a kinetically non-linear generalisation of the well known harmonic category of multiscalar fields over a supporting brane wordsheet in a target space with a curved Riemannian metric. Like the perfectly harmonious case of which a familiar example is pro
Martin Olbermann
In this article, we show the existence of conjugations on many simply-connected spin 6-manifolds with free integral cohomology. In a certain class the only condition on X^6 to admit a conjugation with fixed point set M^3 is the obvious one: the existence of a degree-halving ring isomorphism between the Z_2-cohomologies of X and M.
Chiara Baldovino
Revisiting and completing a work due to A. I. Baškirov, we construct compact sequential spaces of any sequential order up to and including $ω_1$ as quotient spaces of $βω$ under CH.
Bin Chen, Eoin Ó. Colgáin, Jun-Bao Wu, Hossein Yavartanoo
Inspired by the recently discovered holographic duality between N=2 SCFTs and half-BPS M-theory backgrounds, we study probe M5-branes. Though our main focus is supersymmetric M5-branes whose worldvolume has an AdS_n factor, we also consider some other configurations. Of special mention is the identification of AdS_5 and AdS_3 probes preserving supersymmetry,
Mark Hovey, Keir Lockridge
We define homological dimensions for S-algebras, the generalized rings that arise in algebraic topology. We compute the homological dimensions of a number of examples, and establish some basic properties. The most difficult computation is the global dimension of real K-theory KO and its connective version ko at the prime 2. We show that the global dimension
A. V. Nesterenko, C. Simolo
A program package, which facilitates computations in the framework of Analytic approach to QCD, is developed and described in details. The package includes the explicit expressions for relevant spectral functions calculated up to the four-loop level and the subroutines for necessary integrals.
Asja Jelic, Markus Hütter, Hans Christian Öttinger
Dissipative effects in electromagnetism on macroscopic scales are examined by coarse graining the microscopic Maxwell equations with respect to time. We illustrate a procedure to derive the dissipative effects on the macroscopic scale by using a Green-Kubo type expression in terms of the microscopic fluctuations and the correlations between them. The resulti
Pierrick Martin, Jürgen Knödlseder, Jacco Vink, Anne Decourchelle
The medium-lived 44Ti isotope is synthesised by explosive Si-burning in core-collapse supernovae. It is extremely sensitive to the dynamics of the explosion and therefore can be used to indirectly probe the explosion scenario. The young supernova remnant Cassiopeia A is to date the only source of gamma-ray lines from 44Ti decay. The emission flux has been me
Jordan S. Ellenberg, Philippe Michel, Akshay Venkatesh
We discuss Linnik's work on the distribution of integral solutions to $x^2+y^2+z^2 =d$, as $d$ goes to infinity. We give an exposition of Linnik's ergodic method; indeed, by using large-deviation results for random walks on expander graphs, we establish a refinement of his equidistribution theorem. We discuss the connection of these ideas with modern
S. Leurini, B. Parise, P. Schilke, J. Pety
A previous analysis of methanol and formaldehyde towards the Orion Bar concluded that the two molecular species may trace different physical components, methanol the clumpy material, and formaldehyde the interclump medium. To verify this hypothesis, we performed multi-line mapping observations of the two molecules to study their spatial distributions. The ob
Semiconductor-enriched single wall carbon nanotube networks applied to field effect transistors
cond-mat.mtrl-sciNicolas Izard, Saïd Kazaoui, Kenji Hata, Toshiya Okazaki
Substantial progress on field effect transistors "FETs" consisting of semiconducting single wall carbon nanotubes "s-SWNTs" without detectable traces of metallic nanotubes and impurities is reported. Nearly perfect removal of metallic nanotubes is confirmed by optical absorption, Raman measurements, and electrical measurements. This outstandi
Jurek Czyzowicz, Arnaud Labourel, Andrzej Pelc
Two mobile agents (robots) with distinct labels have to meet in an arbitrary, possibly infinite, unknown connected graph or in an unknown connected terrain in the plane. Agents are modeled as points, and the route of each of them only depends on its label and on the unknown environment. The actual walk of each agent also depends on an asynchronous adversary
Jurek Czyzowicz, David Ilcinkas, Arnaud Labourel, Andrzej Pelc
Two mobile agents (robots) have to meet in an a priori unknown bounded terrain modeled as a polygon, possibly with polygonal obstacles. Agents are modeled as points, and each of them is equipped with a compass. Compasses of agents may be incoherent. Agents construct their routes, but the actual walk of each agent is decided by the adversary: the movement of
J. Leenaarts
Numerical simulations of the solar chromosphere have become increasingly realistic over the past 5 years. However, many observed chromospheric structures and behavior are not reproduced. Current models do not show fibrils in Ca II 8542, and neither reproduce the Ca II 8542 bisector. The emergent H-alpha line core intensity computed from the models show granu
Zengyou He, Weichuan Yu
Feature selection techniques have been used as the workhorse in biomarker discovery applications for a long time. Surprisingly, the stability of feature selection with respect to sampling variations has long been under-considered. It is only until recently that this issue has received more and more attention. In this article, we review existing stable featur
Jan Kratochvil, Boris Horvat, Tomaz Pisanski
Some graphs admit drawings in the Euclidean k-space in such a (natu- ral) way, that edges are represented as line segments of unit length. Such drawings will be called k dimensional unit distance representations. When two non-adjacent vertices are drawn in the same point, we say that the representation is degenerate. The dimension (the Euclidean dimension) o
Polyelectrolyte Electrophoresis in Nanochannels: A Dissipative Particle Dynamics Simulation
cond-mat.softJens Smiatek, Friederike Schmid
We present mesoscopic DPD-simulations of polyelectrolyte electrophoresis in confined nanogeometries, for varying salt concentration and surface slip conditions. Special attention is given to the influence of electroosmotic flow (EOF) on the migration of the polyelectrolyte. The effective polyelectrolyte mobility is found to depend strongly on the boundary pr
Hubbard-Stratonovich transformations to self-energies with coset decomposition to anomalous pair condensates for the standard model of electroweak interactions
physics.gen-phBernhard Mieck
The standard model of the strong and electroweak interactions is transformed from the ordinary path integral with the Lagrangians of quarks and leptons and with the Abelian and non-Abelian gauge fields to corresponding self-energies. We apply the precise formulation in terms of massless Majorana Fermi fields with 'Nambu' doubling which naturally lead
Alexander E. Lobkovsky, Francisco Vega Reyes, J. S. Urbach
Recent experimental and computational studies of vibrated thin layers of identical spheres have shown transitions to ordered phases similar to those seen in equilibrium systems. Motivated by these results, we carry out simulations of hard inelastic spheres forced by homogenous white noise. We find a transition to an ordered state of the same symmetry as that
Leilei Shi
Motivated by how transaction amount constrain trading volume and price volatility in stock market, we, in this paper, study the relation between volume and price if amount of transaction is given. We find that accumulative trading volume gradually emerges a kurtosis near the price mean value over a trading price range when it takes a longer trading time, reg
Fedor Zhdanov, Yuri Kalnishkan
Multi-class classification is one of the most important tasks in machine learning. In this paper we consider two online multi-class classification problems: classification by a linear model and by a kernelized model. The quality of predictions is measured by the Brier loss function. We suggest two computationally efficient algorithms to work with these probl
Etienne Gaufrès, Nicolas Izard, Laurent Vivien, Saïd Kazaoui
Photoluminescence properties of semiconducting single wall carbon nanotubes (s-SWNT) thin films with different metallic single wall carbon nanotubes (m-SWNT) concentrations are reported. s-SWNT purified samples are obtained by polymer assisted selective extraction. We show that a few m-SWNT in the sample generates a drastic quenching of the emission. Therefo
DNA heats up : Energetics of genome ejection from phage revealed by isothermal titration calorimetry
physics.bio-phMeerim Jeembaeva, B. Jönsson, Martin Castelnovo, Alex Evilevitch
Most bacteriophages are known to inject their double-stranded DNA into bacteria upon receptor binding in an essentially spontaneous way. This downhill thermodynamic process from the intact virion toward the empty viral capsid plus released DNA is made possible by the energy stored during active packaging of the genome into the capsid. Only indirect measureme
Studying the Kinematics of Faint Stellar Populations with the Planetary Nebula Spectrograph
astro-ph.COMichael R. Merrifield, the PN. S Consortium
Galaxies are faint enough when one observes just their light distributions, but in studying their full dynamical structure the stars are spread over the six dimensions of phase space rather than just the three spatial dimensions, making their densities very low indeed. This low signal is unfortunate, as stellar dynamics hold important clues to these systems&
Ronen Eldan, Bo'az Klartag
We discuss connections between certain well-known open problems related to the uniform measure on a high-dimensional convex body. In particular, we show that the "thin shell conjecture" implies the "hyperplane conjecture". This extends a result by K. Ball, according to which the stronger "spectral gap conjecture" implies the "hype
In-depth studies of the NGC 253 ULXs with XMM-Newton: remarkable variability in ULX1, and evidence for extended coronae
astro-ph.HER. Barnard
We examined the variability of three ultra-luminous X-ray sources (ULXs) in the 2003, 110 ks XMM-Newton observation of NGC253. Remarkably, we discovered ULX1 to be three times more variable than ULX2 in the 0.3--10 keV band, even though ULX2 is brighter. Indeed, ULX1 exhibits a power density spectrum that is consistent with the canonical high state or very h
Francisco M. Fernández
We analyze a recent pedagogical proposal for an alternative treatment of the angular part of the Schr\"odinger equation with a central potential. We show that the authors' arguments are unclear, unconvincing and misleading.
Observation of vortex nucleation in a rotating two-dimensional lattice of Bose-Einstein condensates
cond-mat.quant-gasR. A. Williams, S. Al-Assam, C. J. Foot
We report the observation of vortex nucleation in a rotating optical lattice. A 87Rb Bose-Einstein condensate was loaded into a static two-dimensional lattice and the rotation frequency of the lattice was then increased from zero. We studied how vortex nucleation depended on optical lattice depth and rotation frequency. For deep lattices above the chemical p
Shahram Hosseini, Yannick Deville
An error occurred in the computation of a gradient in our paper entitled "Blind maximum likelihood separation of a linear-quadratic mixture", presented in ICA'2004. The equations (20) in Appendix and (17) in the text were not correct. The current paper presents the correct version of these equations.
Yuji Yoshino, Takeshi Yoshizawa
We propose to define the notion of abstract local cohomology functors. The derived functors of the ordinary local cohomology functor with support in the closed subset defined by an ideal and the generalized local cohomology functor associated with a given pair of ideals are characterized as elements of the set of all the abstract local cohomology functors.
Saverio Braccini
Hadrontherapy is a novel technique of cancer radiation therapy which employs beams of charged hadrons, protons and carbon ions in particular. Due to their physical and radiobiological properties, they allow one to obtain a more conformal treatment with respect to photons used in conventional radiation therapy, sparing better the healthy tissues located in pr
Nuclear Emulsion Film Detectors for Proton Radiography: Design and Test of the First Prototype
physics.med-phS. Braccini, A. Ereditato, I. Kreslo, U. Moser
Proton therapy is nowadays becoming a wide spread clinical practice in cancer therapy and sophisticated treatment planning systems are routinely used to exploit at best the ballistic properties of charged particles. The information on the quality of the beams and the range of the protons is a key issue for the optimization of the treatment. For this purpose,
Robert C. Dalang, Lluis Quer-Sardanyons
We present the Walsh theory of stochastic integrals with respect to martingale measures, alongside of the Da Prato and Zabczyk theory of stochastic integrals with respect to Hilbert-space-valued Wiener processes and some other approaches to stochastic integration, and we explore the links between these theories. We then show how each theory can be used to st
Fei Chen, Bo Zhou, Yan Zhang, Jia Wei
We report the electronic structure of the iron-chalcogenide superconductor, Fe1.04(Te0.66Se0.34), obtained with high resolution angle-resolved photoemission spectroscopy and density functional calculations. In photoemission measurements, various photon energies and polarizations are exploited to study the Fermi surface topology and symmetry properties of the
A. A. Chuprikov, I. A. Guirin
We analyze results of data processing of observations of well-known object titled SS433 with the VLBA during more than 10 years. Data have been processed with the software project titled 'Astro Space Locator' (ASL for Windows). The Multi Frequency Synthesis (MFS) method has been used for reconstruction of radio maps at 18 and 6 centimeter wavelength
G. Pacelli Bessa, J. Fabio Montenegro, Paolo Piccione
We prove some estimates on the spectrum of the Laplacian of the total space of a Riemannian submersion in terms of the spectrum of the Laplacian of the base and the geometry of the fibers. When the fibers of the submersions are compact and minimal, we prove that the total space is discrete if and only if the base is discrete. When the fibers are not minimal,
R. K. Zamanov, S. Boeva, R. Bachev, M. F. Bode
We report observations of the flickering variability of the recurrent nova RS Oph at quiescence on the basis of simultaneous observations in 5 bands (UBVRI). RS Oph has flickering source with (U-B)_0=-0.62 \pm 0.07, (B-V)_0=0.15 \pm 0.10, (V-R)_0=0.25 \pm 0.05. We find for the flickering source a temperature T_fl = 9500 \pm 500 K, and luminosity L_fl = 50 -
Left ideals in an enveloping algebra, prelie products and applications to simple complex Lie algebras
math.RALoïc Foissy
We characterize prelie algebras in words of left ideals of the enveloping algebras and in words of modules, and use this result to prove that a simple complex finite-dimensional Lie algebra is not prelie, with the possible exception of f4.
Yoritaka Iwata, Takaharu Otsuka, Joachim A. Maruhn, Naoyuki Itagaki
Charge equilibration between two colliding nuclei can take place in the early stage of heavy-ion collisions. A basic mechanism of charge equilibration is presented in terms of the extension of single-particle motion from one nucleus to the other, from which the upper energy-limit of the bombarding energy is introduced for significant charge equilibration at
S. Capozziello, A. Stabile, A. Troisi
We formally discuss the post-Minkowskian limit of $f(R)$-gravity without adopting conformal transformations but developing all the calculations in the original Jordan frame. It is shown that such an approach gives rise, in general, together with the standard massless graviton, to massive scalar modes whose masses are directly related to the analytic paramete
N. V. Gritsienko, A. V. Latyshev, A. A. Yushkanov
In the present work the linearized problem of plasma wave reflection from a boundary of a half--space is solved analytically. Specular accommodative conditions of plasma wave reflection from plasma boundary are taken into consideration. Wave reflectance is found as function of the given parameters of the problem, and its dependence on the normal electron mom
Zhe Chang, Ning Wu
We study the evolution of nearest-neighbor entanglement in the one dimensional Ising model with an external transverse field. The system is initialized as the so called "thermal ground state" of the pure Ising model. We analyze properties of generation of entanglement for different regions of external transverse fields. We find that the derivation of
B. Dintrans
Overshooting occurs in stars when convective elements penetrate into adjacent radiative zones. In the Sun, it leads to the so-called `tachocline' at the base of the outer convection zone and this region is becoming a key ingredient of the standard solar dynamo model as strong toroidal magnetic fields may be generated there. However this overshoot is not
A. K. Bhattacharjee, Gautam I. Menon, R. Adhikari
We construct Langevin equations describing the fluctuations of the tensor order parameter $Q_{αβ}$ in nematic liquid crystals by adding noise terms to time-dependent variational equations that follow from the Ginzburg-Landau-de Gennes free energy. The noise is required to preserve the symmetry and tracelessness of the tensor order parameter and must satisfy
R. Juhász, F. Iglói
We study diffusion of a particle in a system composed of K parallel channels, where the transition rates within the channels are quenched random variables whereas the inter-channel transition rate v is homogeneous. A variant of the strong disorder renormalization group method and Monte Carlo simulations are used. Generally, we observe anomalous diffusion, wh
Igor Sega, Peter Prelovsek
The memory function approach to spin dynamics in doped antiferromagnetic insulator combined with the assumption of temperature independent static spin correlations and constant collective mode damping leads to omega/T scaling in a broad range. The theory involving a non universal scaling parameter is used to analyze recent inelastic neutron scattering result
Sahin Buyukdagli, Marc Joyeux
We investigate a model system consisting of a Morse oscillator strongly coupled to a doubly-degenerate bending degree of freedom and show that Canonical Perturbation Theory is able to provide a fairly precise, though not exact, approximation of the Hamiltonian up to the dissociation threshold. Quantum mechanical results and classical ones are discussed in th
Longyun Ding
Let $X_n, n\in\Bbb N$ be a sequence of non-empty sets, $ψ_n:X_n^2\to\Bbb R^+$. We consider the relation $E((X_n,ψ_n)_{n\in\Bbb N})$ on $\prod_{n\in\Bbb N}X_n$ by $(x,y)\in E((X_n,ψ_n)_{n\in\Bbb N})\Leftrightarrow\sum_{n\in\Bbb N}ψ_n(x(n),y(n))<+\infty$. If $E((X_n,ψ_n)_{n\in\Bbb N})$ is a Borel equivalence relation, we show a trichotomy that either $\Bbb R^\
B. C. Yang, M. L. Du
The total photodetachment cross section of a linear triatomic anion is derived for arbitrary laser polarization direction. The cross section is shown to be strongly oscillatory when the laser polarization direction is parallel to the axis of the system; the oscillation amplitude decreases and vanishes as the angle between the laser polarization and the anion