April 2010 arXiv papers — page 33

A. Amaya-Tapia, S. Y. Larsen, M. Lassaut

In one of the very few exact quantum mechanical calculations of fugacity coefficients, Dodd and Gibbs (\textit{J. Math.Phys}.,\textbf{15}, 41 (1974)) obtained $b_{2}$ and $b_{3}$ for a one dimensional Bose gas, subject to repulsive delta-function interactions, by direct integration of the wave functions. For $b_{2}$, we have shown (\textit{Mol. Phys}.,\textb

J. J. Mazo, F. Naranjo, D. Zueco

We study the thermal escape problem in the low damping limit. We find that finiteness of the barrier is crucial for explaining the thermal activation results. In this regime low barrier non-equilibrium corrections to the usual theories become necessary. We propose a simple theoretical extension accounting for these non-equilibrium processes which agrees nume

Edward J. Allen

Stochastic difference equations and a stochastic partial differential equation (SPDE) are simultaneously derived for the time-dependent neutron angular density in a general three-dimensional medium where the neutron angular density is a function of position, direction, energy, and time. Special cases of the equations are given such as transport in one-dimens

Francisco M. Fernández

We discuss the application of perturbation theory to a system of particles confined in a spherical box. A simple argument shows that the particles behave almost independently in sufficiently strong confinement. We choose the helium atom with a moving nucleus as a particular example and compare results of first order with those for the nucleus clamped at the

Victor Orlov, Alexey Rubinov, Ivan Shevchenko

We investigate statistics of the decay process in the equal-mass three-body problem with randomized initial conditions. Contrary to earlier expectations of similarity with "radioactive decay", the lifetime distributions obtained in our numerical experiments turn out to be heavy-tailed, i.e. the tails are not exponential, but algebraic. The computed p

Sergei Ivanov

The main subject of this expository paper is a connection between Gromov's filling volumes and a boundary rigidity problem of determining a Riemannian metric in a compact domain by its boundary distance function. A fruitful approach is to represent Riemannian metrics by minimal surfaces in a Banach space and to prove rigidity by studying the equality cas

Lawrence Krauss, Scott Dodelson, Stephan Meyer

The observation of primordial gravitational waves could provide a new and unique window on the earliest moments in the history of the universe, and on possible new physics at energies many orders of magnitude beyond those accessible at particle accelerators. Such waves might be detectable soon in current or planned satellite experiments that will probe for c

Dominique Aubert, Romain Teyssier

We present a set of cosmological simulations with radiative transfer in order to model the reionization history of the Universe. Galaxy formation and the associated star formation are followed self-consistently with gas and dark matter dynamics using the RAMSES code, while radiative transfer is performed as a post-processing step using a moment-based method

Mikhail Belishev, Aleksei Vakulenko

The notion of $s$-points has been introduced by the authors (SIAM JMA, 39 (2008), 1821--1850) in connection with the control problem for the dynamical system governed by the $3\rm d$ acoustical equation $u_{tt}-Δu+qu=0$ with a real potential $q \in C^\infty_0({{\mathbb R}^3})$ and controlled by incoming spherical waves. In the generic case, this system is co

Anna N. Morozovska

Using direct variational method with 2-parametric trial function and Landau-Ginzburg-Devonshire thermodynamical approach, we derived analytical expressions for polarization spatial redistribution in the ferroelectrics caused by the biased Scanning Probe Microscope probe. We demonstrate that the shape of nanodomain induced by the probe electric field can be e

Derek Hammer, Ann Hornschemeier, Bahram Mobasher, Neal Miller

We present a source catalog from deep 26 ks GALEX observations of the Coma cluster in the far-UV (FUV; 1530 A) and near-UV (NUV; 2310 A) wavebands. The observed field is centered 0.9 deg (1.6 Mpc) south-west of the Coma core, and has full optical photometric coverage with SDSS. The catalog consists of 9700 galaxies with GALEX and SDSS photometry, including 2

Siegfried Roeser, Nina V. Kharchenko, Anatoly E. Piskunov, Elena Schilbach

It is textbook knowledge that open clusters are conspicuous members of the thin disk of our Galaxy, but their role as contributors to the stellar population of the disk was regarded as minor. Starting from a homogenous stellar sky survey, the ASCC-2.5, we revisited the population of open clusters in the solar neighbourhood from scratch. In the course of this

Yan He, Vladimir Cvetkovic, C. M. Varma

We consider the thermal expansion, change of sound velocity with pressure and temperature, and the Poisson ratio of lattices which have rigid units (polyhedra very large stiffness to change in bond-length and to bond-angle variations) connected to other such units through relatively compressible polyhedra. We show that in such a model, the potential energy f

F. Massaro, J. E. Grindlay, A. Paggi

Gamma Ray Bursts (GRBs) show evidence of different light curves, duration, afterglows, host galaxies and they explode within a wide redshift range. However, their spectral energy distributions (SEDs) appear to be very similar showing a curved shape. Band et al. (1993) proposed a phenomenological description of the integrated spectral shape for the GRB prompt

Paul J. Howell, Tereasa G. Brainerd

We use Monte Carlo simulations to investigate the theory of galaxy-galaxy lensing by non-spherical dark matter haloes. The simulations include a careful accounting of the effects of multiple deflections. In a typical data set where the mean tangential shear of sources with redshifts zs ~ 0.6 is measured with respect to the observed symmetry axes of foregroun

Mark Dijkstra, Stuart Wyithe

The next generation of telescopes aim to directly observe the first generation of galaxies that initiated the reionization process in our Universe. The Lyman Alpha (Lya) emission line is robustly predicted to be the most prominent intrinsic spectral feature of these galaxies, making it an ideal target to search for and study high redshift galaxies. Unfortuna

Daniel Baumann, Alberto Nicolis, Leonardo Senatore, Matias Zaldarriaga

The universe is smooth on large scales but very inhomogeneous on small scales. Why is the spacetime on large scales modeled to a good approximation by the Friedmann equations? Are we sure that small-scale non-linearities do not induce a large backreaction? Related to this, what is the effective theory that describes the universe on large scales? In this pape

Aaron Skinner, Eve Ostriker

A method for implementing cylindrical coordinates in the Athena magnetohydrodynamics (MHD) code is described. The extension follows the approach of Athena's original developers and has been designed to alter the existing Cartesian-coordinates code as minimally and transparently as possible. The numerical equations in cylindrical coordinates are formulate

Pilar Herreros

It has been shown in \cite{DPSU} that, under some additional assumptions, two simple domains with the same scattering data are equivalent. We show that the simplicity of a region can be read from the metric in the boundary and the scattering data. This lets us extend the results in \cite{DPSU} to regions with the same scattering data, where only one is known

Swastik Kopparty, Benjamin Rossman

We initiate a study of the homomorphism domination exponent of a pair of graphs F and G, defined as the maximum real number c such that |Hom(F,T)| \geq |Hom(G,T)|^c for every graph T. The problem of determining whether HDE(F,G) \geq 1 is known as the homomorphism domination problem and its decidability is an important open question arising in the theory of r

Detlev W. Hoffmann

Let F be a field of characteristic different from 2. The u-invariant and the Hasse number of a field F are classical and important field invariants pertaining to quadratic forms. These invariants measure the suprema of dimensions of anisotropic forms over F that satisfy certain additional properties. We construct various examples of fields with infinite Hass

Alan Frieze, Michael Krivelevich, Po-Shen Loh

We consider several variants of the classical Cops and Robbers game. We treat the version where the robber can move R > 1 edges at a time, establishing a general upper bound of N / α^{(1-o(1))\sqrt{log_α N}}, where α = 1 + 1/R, thus generalizing the best known upper bound for the classical case R = 1 due to Lu and Peng. We also show that in this case, the co

Bart de Smit, Mathieu Florence, Lara Thomas

If $L/K$ is a finite Galois extension of local fields, we say that the valuation criterion $VC(L/K)$ holds if there is an integer $d$ such that every element $x \in L$ with valuation $d$ generates a normal basis for $L/K$. Answering a question of Byott and Elder, we first prove that $VC(L/K)$ holds if and only if the tamely ramified part of the extension $L/

A. Sanna, L. Moscadelli, R. Cesaroni, A. Tarchi

The present paper focuses on the high-mass star-forming region G16.59-0.05. Methods: Using the VLBA and the EVN arrays, we conducted phase-referenced observations of the three most powerful maser species in G16.59-0.05: H2O at 22.2 GHz (4 epochs), CH3OH at 6.7 GHz (3 epochs), and OH at 1.665 GHz (1 epoch). In addition, we performed high-resolution (> 0".

N. Eggemann, S. D. Noble

We consider two orientation problems in a graph, namely the minimization of the sum of all the shortest path lengths and the minimization of the diameter. We show that it is NP-complete to decide whether a graph has an orientation such that the sum of all the shortest paths lengths is at most an integer specified in the input. The proof is a short reduction

David Jou, Maria Stella Mongiovi', Michele Sciacca, Carlo F. Barenghi

By assuming a self-similar structure for Kelvin waves along vortex loops with successive smaller scale features, we model the fractal dimension of a superfluid vortex tangle in the zero temperature limit. Our model assumes that at each step the total energy of the vortices is conserved, but the total length can change. We obtain a relation between the fracta

Otto P. Behre, Heinrich J. Wendker, Lloyd A. Higgs, Thomas L. Landecker

The radio source 18P87, previously thought to be a point source, has been serendipitously found to be resolved into a core-jet geometry in VLA maps. HI absorption of continuum emission (in data from the Canadian Galactic Plane Survey) appears in gas with radial velocities > +2 km/s but not in brightly emitting gas at lower radial velocity. Examination of fur

Urs Schreiber, Zoran Škoda

Quantum field theory allows more general symmetries than groups and Lie algebras. For instance quantum groups, that is Hopf algebras, have been familiar to theoretical physicists for a while now. Nowdays many examples of symmetries of categorical flavor -- categorical groups, groupoids, Lie algebroids and their higher analogues -- appear in physically motiva

M. Cattani

In a recent paper we have deduced the basic equations that predict the emission of gravitational waves (GW) according to the Einstein gravitation theory. In a subsequent paper these equations have been used to calculate the luminosities and the amplitudes of the waves generated by binary stars, pulsations of neutron stars, wobbling of deformed neutron stars,

Mikael Afzelius, Christoph Simon

We consider an atomic frequency comb based quantum memory inside an asymmetric optical cavity. In this configuration it is possible to absorb the input light completely in a system with an effective optical depth of one, provided that the absorption per cavity round trip exactly matches the transmission of the coupling mirror ("impedance matching").

Madalin Guta, Wojciech Kotlowski

Pattern recognition is a central topic in Learning Theory with numerous applications such as voice and text recognition, image analysis, computer diagnosis. The statistical set-up in classification is the following: we are given an i.i.d. training set $(X_{1},Y_{1}),... (X_{n},Y_{n})$ where $X_{i}$ represents a feature and $Y_{i}\in \{0,1\}$ is a label attac

Caterina Scoglio, Walter Schumm, Phillip Schumm, Todd Easton

Containing an epidemic at its origin is the most desirable mitigation. Epidemics have often originated in rural areas, with rural communities among the first affected. Disease dynamics in rural regions have received limited attention, and results of general studies cannot be directly applied since population densities and human mobility factors are very diff

Brian Kloppenborg, Robert Stencel, John D. Monnier, Gail Schaefer

Eclipses of the single-line spectroscopic binary star, epsilon Aurigae, provide an opportunity to study the poorly-defined companion. We used the MIRC beam combiner on the CHARA array to create interferometric images during eclipse ingress. Our results demonstrate that the eclipsing body is a dark disk that is opaque and tilted, and therefore exclude alterna

S. G. Rajeev

Arnold showed that the Euler equations of an ideal fluid describe geodesics on the Lie algebra of incompressible vector fields. We generalize this to fluids with dissipation and Gaussian random forcing. The dynamics is determined by the structure constants of a Lie algebra, along with inner products defining kinetic energy, Ohmic dissipation and the covarian

András Csernenszky

One of the main objective of this paper is to relate Beck's conjecture for k-in-a-row games. The conjecture states that playing on the same board Picker is better off in a Chooser-Picker game than the second player in the Maker-Breaker version. It was shown that the 8-in-a-row game is a blocking draw that is a Breaker win. To give the outcome of 7-, or 6

Jacob Moldenhauer, Mustapha Ishak, John Thompson, Damien A. Easson

We consider recently proposed higher order gravity models where the action is built from the Einstein-Hilbert action plus a function f(G) of the Gauss-Bonnet invariant. The models were previously shown to pass physical acceptability conditions as well as solar system tests. In this paper, we compare the models to combined data sets of supernovae, baryon acou

Norio Narita, Tomoyuki Kudo, Carolina Bergfors, Makiko Nagasawa

We present results of direct imaging observations for HAT-P-7 taken with the Subaru HiCIAO and the Calar Alto AstraLux. Since the close-in transiting planet HAT-P-7b was reported to have a highly tilted orbit, massive bodies such as giant planets, brown dwarfs, or a binary star are expected to exist in the outer region of this system. We show that there are

K. O. Babalola

In this note we give some sufficient conditions for an analytic function $f(z)$ normalized by $f'(0)=1$ to belong to certain subfamilies of the class of Bazilevic functions. In earlier works, the closure property of many classes of functions under the Bernardi integral have been considered. The converse of this problem is also considered here.

Joaquim Ortega-Cerdà, Bharti Pridhnani

Given a compact Riemannian manifold $M$ of dimension $m\geq 2$, we study the space of functions of $L^2(M)$ generated by eigenfunctions of eigenvalues less than $L\geq 1$ associated to the Laplace-Beltrami operator on $M$. On these spaces we give a characterization of the Carleson measures and the Logvinenko-Sereda sets.

P. Castorina, A. Iorio, D. Zappalá

The experimental detection of the effects of noncommuting coordinates in electrodynamic phenomena depends on the magnitude of |θB|, where θis the noncommutativity parameter and B a background magnetic field. With the present upper bound on θ, given by θ_{\rm bound} \simeq 1/(10 {\rm TeV})^2, there was no large enough magnetic field in nature, including those

Tewodros Amdeberhan, Olivier R. Espinosa, Victor H. Moll, Armin Straub

One of the earliest examples of analytic representations for $π$ is given by an infinite product provided by Wallis in 1655. The modern literature often presents this evaluation based on the integral formula $$ \frac{2}π \int_0^\infty \frac{dx}{(x^2+1)^{n+1}} = \frac{1}{2^{2n}} \binom{2n}{n}. $$ In trying to understand the behavior of this integral when the

A. C. Lehum, J. R. Nascimento, A. Yu. Petrov

In this work we study the effective potential in noncommutative three-dimensional models where the noncommutativity is introduced through the coherent state approach. We discuss some important characteristics that seem to be typical to this approach, specially the behavior of the quantum corrections in the small noncommutativity limit.

A. A. Breeveld, P. A. Curran, E. A. Hoversten, S. Koch

The Ultraviolet/Optical Telescope (UVOT) is one of three instruments onboard the Swift observatory. The photometric calibration has been published, and this paper follows up with details on other aspects of the calibration including a measurement of the point spread function with an assessment of the orbital variation and the effect on photometry. A correcti

J. Faden, R. S. Weigel, J. Merka, R. H. W. Friedel

Autoplot is software developed for the Virtual Observatories in Heliophysics to provide intelligent and automated plotting capabilities for many typical data products that are stored in a variety of file formats or databases. Autoplot has proven to be a flexible tool for exploring, accessing, and viewing data resources as typically found on the web, usually

Bernhard G. Bodmann, Peter G. Casazza, Vern I. Paulsen, Darrin Speegle

We answer a number of open problems in frame theory concerning the decomposition of frames into linearly independent and/or spanning sets. We prove that in finite dimensional Hilbert spaces, Parseval frames with norms bounded away from 1 can be decomposed into a number of sets whose complements are spanning, where the number of these sets only depends on the

T. Amdeberhan, M. L. Glasser, M. C. Jones, V. H. Moll

The Cauchy-Schlömilch transformation states that for a function $f$ and $a, \, b > 0$, the integral of $f(x^{2})$ and $af((ax-bx^{-1})^{2}$ over the interval $[0, \infty)$ are the same. This elementary result is used to evaluate many non-elementary definite integrals, most of which cannot be obtained by symbolic packages. Applications to probability distribu

Youchang Yang, Jialun Ping

Considering the coupling of color $1 \otimes 1$ and $8 \otimes 8$ structures, we calculate the energy of the newly observed $X$(3915) as $S-$wave $D^*\bar{D^*}$ state in the Bhaduri, Cohler, and Nogami quark model by the Gaussian Expansion Method. Due to the color coupling, the bound state of $D^*\bar{D^*}$ with $J^{PC}=0^{++}$ is found, which is well conson

Xuepeng Chen, Hector G. Arce, Qizhou Zhang, Tyler L. Bourke

Intermediate between the prestellar and Class 0 protostellar phases, the first core is a quasi-equilibrium hydrostatic object with a short lifetime and an extremely low luminosity. Recent MHD simulations suggest that the first core can even drive a molecular outflow before the formation of the second core (i.e., protostar). Using the Submillimeter Array and

Martin Mücke, Eden Figueroa, Joerg Bochmann, Carolin Hahn

Optical nonlinearities offer unique possibilities for the control of light with light. A prominent example is electromagnetically induced transparency (EIT) where the transmission of a probe beam through an optically dense medium is manipulated by means of a control beam. Scaling such experiments into the quantum domain with one, or just a few particles of b

Tewodros Amdeberhan, Victor H. Moll

An elementary proof of an entry in the table of integrals by Gradshteyn and Rhyzik is presented.

Victor H. Moll

The table of Gradshteyn and Rhyzik contains some trigonometric integrals that can be expressed in terms of the beta function. We describe the evaluation of some of them.

Victor H. Moll, Ronald A. Posey

We present the evaluation of some logarithmic integrals. The integrand contains a rational function with complex poles. The methods are illustrated with examples found in the classical table of integrals by I. S. Gradshteyn and I. M. Ryzhik.

Maxim Lyutikov, Matthew Lister

Magnetically-driven non-stationary acceleration of jets in AGNs results in the leading parts of the flow been accelerated to much higher Lorentz factors than in the case of steady state acceleration with the same parameters. The higher Doppler-boosted parts of the flow may dominate the high energy emission of blazar jets. We suggest that highly variable GeV

Maxim Lyutikov

We consider dynamical scales in magnetized GRB outflows, using the solutions to the Riemann problem of expanding arbitrarily magnetized outflows (Lyutikov 2010). For high ejecta magnetization, the behavior of the forward shock closely resembles the so-called thick shell regime of the hydrodynamical expansion. The exception is at small radii, where the motion

Zoltan Esik, Andreas Maletti

For several semirings S, two weighted finite automata with multiplicities in S are equivalent if and only if they can be connected by a chain of simulations. Such a semiring S is called "proper". It is known that the Boolean semiring, the semiring of natural numbers, the ring of integers, all finite commutative positively ordered semirings and all fi

Vishwambhar Rathi, Erik Aurell, Lars Rasmussen, Mikael Skoglund

We consider the regular balanced model of formula generation in conjunctive normal form (CNF) introduced by Boufkhad, Dubois, Interian, and Selman. We say that a formula is $p$-satisfying if there is a truth assignment satisfying $1-2^{-k}+p 2^{-k}$ fraction of clauses. Using the first moment method we determine upper bound on the threshold clause density su

Santanu K. Maiti

We explore the possibilities of designing classical logic gates at nano-scale level using magnetic quantum rings. A single ring is used for designing OR, NOT, XOR, XNOR and NAND gates, while AND and NOR gate responses are achieved using two such rings and in all the cases each ring is threaded by a magnetic flux $ϕ$ which plays the central role in the logic

Tom Bohman, Alan Frieze, Eyal Lubetzky

The random greedy algorithm for constructing a large partial Steiner-Triple-System is defined as follows. We begin with a complete graph on $n$ vertices and proceed to remove the edges of triangles one at a time, where each triangle removed is chosen uniformly at random from the collection of all remaining triangles. This stochastic process terminates once i

Timm Krüger, Fathollah Varnik, Dierk Raabe

The deformation of an initially spherical capsule, freely suspended in simple shear flow, can be computed analytically in the limit of small deformations [D. Barthes-Biesel, J. M. Rallison, The Time-Dependent Deformation of a Capsule Freely Suspended in a Linear Shear Flow, J. Fluid Mech. 113 (1981) 251-267]. Those analytic approximations are used to study t

W. A. Baan, A. F. Loenen, M. Spaans

Molecules that trace the high-density regions of the interstellar medium may be used to evaluate the changing physical and chemical environment during the ongoing nuclear activity in (Ultra-)Luminous Infrared Galaxies. The changing ratios of the HCN(1-0), HNC(1-0), HCO+(1-0), CN(1-0) and CN(2-1), and CS(3-2) transitions were compared with the HCN(1-0)/CO(1-0

R. Gilli, A. Comastri, C. Vignali, P. Ranalli

Our current understanding of the evolution of obscured accretion onto supermassive black holes is reviewed. We consider the literature results on the relation between the fraction of moderately obscured, Compton-thin AGN and redshift, and discuss the biases which possibly affect the various measurements. Then, we discuss a number of methods - from ultradeep

David R. Heine, Matt K. Petersen, Gary S. Grest

The rheology of nanoparticle suspensions for nanoparticles of various shapes with equal mass is studied using molecular dynamics simulations. The equilibrium structure and the response to imposed shear are analyzed for suspensions of spheres, rods, plates, and jacks in an explicit solvent for both charged and uncharged nanoparticles. For the volume fraction

Matteo Martinelli, Laura Lopez Honorez, Alessandro Melchiorri, Olga Mena

Cosmic Microwave Background satellite missions as the on-going Planck experiment are expected to provide the strongest constraints on a wide set of cosmological parameters. Those constraints, however, could be weakened when the assumption of a cosmological constant as the dark energy component is removed. Here we show that it will indeed be the case when the

Ralf Schützhold

A sweep through a quantum phase transition by means of a time-dependent external parameter (e.g., pressure) entails non-equilibrium phenomena associated with a break-down of adiabaticity: At the critical point, the energy gap vanishes and the response time diverges (in the thermodynamic limit). Consequently, the external time-dependence inevitably drives the

Carlos Alvarado, Paolo Amore

We obtain systematic approximations to the states (energies and wave functions) of quantum rings (annular drums) of arbitrary shape by conformally mapping the annular domain to a simply connected domain. Extending the general results of Ref.\cite{Amore09} we obtain an analytical formula for the spectrum of quantum ring of arbirtrary shape: for the cases of a

Lorenzo Iorio

Binary systems containing at least one radiopulsar are excellent laboratories to test several aspects of fundamental physics like matter properties in conditions of extreme density and theories of gravitation like the Einstein's General Theory of Gravitation (GTR) along with modifications/extensions of it. In this Chapter we focus on the perspectives on

M. Sumetsky, Y. Dulashko, R. S. Windeler

An optical resonator is often called fully tunable if its tunable range exceeds the spectral interval that contains the resonances at all the characteristic modes of this resonator. For the high Q-factor spheroidal and toroidal microresonators, this interval coincides with the azimuthal free spectral range. In this Letter, we demonstrate the first mechanical

S. Blanc, Y. Gallais, M. Cazayous, M. A. Measson

Conventional superconductors are characterized by a single energy scale, the superconducting gap, which is proportional to the critical temperature Tc . In hole-doped high-Tc copper oxide superconductors, previous experiments have established the existence of two distinct energy scales for doping levels below the optimal one. The origin and significance of t

Johannes Broedel, Song He

Infrared equations and dual conformal constraints arise as consistency conditions on loop amplitudes in N=4 super Yang-Mills theory. These conditions are linear relations between leading singularities, which can be computed in the Grassmannian formulation of N=4 super Yang-Mills theory proposed recently. Examples for infrared equations have been shown to be

Ralf Schützhold, Clovis Maia

In addition to the Larmor radiation known from classical electrodynamics, electrons in a laser field may emit pairs of entangled photons -- which is a pure quantum effect. We investigate this quantum effect and discuss why it is suppressed in comparison with the classical Larmor radiation (which is just Thomson backscattering of the laser photons). Further,

Mihai N. Pascu

In a series of papers, Burdzy et. al. introduced the \emph{mirror coupling} of reflecting Brownian motions in a smooth bounded domain $D\subset \mathbb{R}^{d}$, and used it to prove certain properties of eigenvalues and eigenfunctions of the Neumann Laplaceian on $D$. In the present paper we show that the construction of the mirror coupling can be extended t

Ralf Schützhold

This article provides a brief overview of some fundamental effects of quantum fields under extreme conditions. For the Schwinger mechanism, Hawking radiation, and the Unruh effect, analogies to quantum optics are discussed, which might help to approach to these phenomena from an experimental point of view.

Ralf Schützhold

This article provides a brief (non-exhaustive) overview of some possibilities for recreating fundamental effects which are relevant for black holes (and other gravitational scenarios) in the laboratory. Via suitable condensed matter analogues and other laboratory systems, it might be possible to model the Penrose process (superradiant scattering), the Unruh

Ø. Ryan

Observations where additive noise is present can for many models be grouped into a compound observation matrix, adhering to the same type of model. There are many ways the observations can be stacked, for instance vertically, horizontally, or quadratically. An estimator for the spectrum of the underlying model can be formulated for each stacking scenario in

M. Mugrauer, T. Berthold

The Schmidt-Teleskop-Kamera (STK) is a new CCD-imager, which is operated since begin of 2009 at the University Observatory Jena. This article describes the main characteristics of the new camera. The properties of the STK detector, the astrometry and image quality of the STK, as well as its detection limits at the 0.9m telescope of the University Observatory

Masayuki Ohzeki, Hidetoshi Nishimori

We study the applications of non-equilibrium relations such as the Jarzynski equality and fluctuation theorem to spin glasses with gauge symmetry. It is shown that the exponentiated free-energy difference appearing in the Jarzynski equality reduces to a simple analytic function written explicitly in terms of the initial and final temperatures if the temperat

Osamu Yasuda

Sensitivity of a neutrino factory to various mixing angles in a scheme with one sterile neutrino is studied using $ν_e\toν_μ$, $ν_μ\toν_μ$, $ν_e\toν_τ$ and $ν_μ\toν_τ$. While the "discovery-channel" $ν_μ\toν_τ$ is neither useful in the standard three flavor scheme nor very powerful in the sensitivity study of sterile neutrino mixings, this channel is

Jovan P. Šetrajčić

The main problem in theoretical analysis of structures with strong confinement is the fact that standard mathematical tools: differential equations and Fourier's transformations are no longer applicable. In this paper we have demonstrated that method of Green's functions can be successfully used on low-dimension crystal samples, as a consequence of q

Kazem Haghnejad Azar

In this article, for Banach left and right module actions, we will extend some propositions from Lau and $\ddot{U}lger$ into general situations and we establish the relationships between topological centers of module actions. We also introduce the new concepts as $Lw^*w$-property and $Rw^*w$-property for Banach $A-bimodule$ $B$ and we investigate the relatio

Martin Tautenhahn, Ivan Veselić

We discuss recent results on spectral properties of discrete alloy-type random Schrödinger operators. They concern Wegner estimates and bounds on the fractional moments of the Green's function.

Christoph I Westbrook, Denis Boiron

This paper discusses our recent work on developing the matter wave analogs to the Hanbury Brown Twiss experiment. We discuss experiments using cold atoms, both bosons and fermions, both coherent and incoherent. Simple concepts from classical and quantum optics suffice to understand most of the results, but the ideas can also be traced back to the work of Ein

Anne M. Green

WIMP direct detection experiments probe the ultra-local dark matter density and velocity distribution. We review how uncertainties in these quantities affect the accuracy with which the WIMP mass and cross-section can be constrained or determined.

Sebastien Fromang

This letter investigates the transport properties of MHD turbulence induced by the magnetorotational instability at large Reynolds numbers Re when the magnetic Prandtl number Pm is larger than unity. Three MHD simulations of the magnetorotational instability (MRI) in the unstratified shearing box with zero net flux are presented. These simulations are perfor

N. I. Stoilova, J. Van der Jeugt

A Gel'fand-Zetlin basis is introduced for the irreducible covariant tensor representations of the Lie superalgebra gl(m|n). Explicit expressions for the generators of the Lie superalgebra acting on this basis are determined. Furthermore, Clebsch-Gordan coefficients corresponding to the tensor product of any covariant tensor representation of gl(m|n) with

S. M. Crawford, A. L. Ratsimbazafy, C. M. Cress, E. A. Olivier

There have been a number of attempts to measure the expansion rate of the universe at high redshift using Luminous Red Galaxies (LRGs) as "chronometers". The method generally assumes that stars in LRGs are all formed at the same time. In this paper, we quantify the uncertainties on the measurement of H(z) which arise when one considers more realistic

Qianxue Wang, Christophe Guyeux, Jacques M. Bahi

Security of information transmitted through the Internet, against passive or active attacks is an international concern. The use of a chaos-based pseudo-random bit sequence to make it unrecognizable by an intruder, is a field of research in full expansion. This mask of useful information by modulation or encryption is a fundamental part of the TLS Internet e

N. B. Ivanov, J. Schnack, R. Schnalle, J. Richter

We report on refined experimental results concerning the low-temperature specific heat of the frustrated spin tube material [(CuCl2tachH)3Cl]Cl2. This substance turns out to be an unusually perfect spin tube system which allows to study the physics of quasi-one dimensional antiferromagnetic structures in rather general terms. An analysis of the specific heat

Geert Jan Bex, Wouter Gelade, Frank Neven, Stijn Vansummeren

Inferring an appropriate DTD or XML Schema Definition (XSD) for a given collection of XML documents essentially reduces to learning deterministic regular expressions from sets of positive example words. Unfortunately, there is no algorithm capable of learning the complete class of deterministic regular expressions from positive examples only, as we will show

Lorenzo Bertini, Giacomo Di Gesù

We consider, for a diffusion process in R^n, the Gallavotti-Cohen functional, defined as the empirical power dissipated in a time interval by the non-conservative part of the drift. We prove a large deviation principle in the limit in which the noise vanishes and the time interval diverges. The corresponding rate functional, which satisfies the fluctuation t

J. M. J. van Leeuwen, Andrzej Drzewinski

Linear polymers are represented as chains of hopping reptons and their motion is described as a stochastic process on a lattice. This admittedly crude approximation still catches essential physics of polymer motion, i.e. the universal properties as function of polymer length. More than the static properties, the dynamics depends on the rules of motion. Small

M. Mugrauer, R. Neuhäuser, C. Ginski, T. Eisenbeiss

We present recent results of our ongoing multiplicity study of exoplanet host stars.

L. Uscanga, J. Cantó, J. F. Gómez, G. Anglada

We have done a statistical analysis of Very Long Baseline Array (VLBA) data of water masers in the star-forming regions (SFRs) Cepheus A and W75 N, using correlation functions to study the spatial clustering and Doppler-velocity distribution of these masers. Two-point spatial correlation functions show a characteristic scale size for clusters of water maser

Krishnendu Chatterjee, Thomas A. Henzinger, Barbara Jobstmann, Arjun Radhakrishna

Gist is a tool that (a) solves the qualitative analysis problem of turn-based probabilistic games with ω-regular objectives; and (b) synthesizes reasonable environment assumptions for synthesis of unrealizable specifications. Our tool provides the first and efficient implementations of several reduction-based techniques to solve turn-based probabilistic game

J. Billard, F. Mayet, J. F. Macias-Perez, D. Santos

Directional detection of galactic Dark Matter is a promising search strategy for discriminating genuine WIMP events from background ones. However, to take full advantage of this powerful detection method, one need to be able to extract information from an observed recoil map to identify a WIMP signal. We present a comprehensive formalism, using a map-based l

Daoshun Wang, Lin Dong, Xiaobo Li

In (k, n) visual secret sharing (VSS) scheme, secret image can be visually reconstructed when k or more participants printing theirs shares on transparencies and stack them together. No secret is revealed with fewer than k shares. The alignment of the transparencies is important to the visual quality of the reconstructed secret image. In VSS scheme, each pix

Wojciech Szewczuk, Jadwiga Daszyńska-Daszkiewicz

We discuss all possible sources of uncertainties in theoretical values of the photometric amplitudes and phases of B-type main sequence pulsators. These observables are of particular importance because they contain information about the mode geometry as well as about stellar physics. Here, we study effects of various parameters coming both from theory of lin

O. B. Zaslavskii

We establish the relationship between the space-time structure of regular spherically-symmetrical black holes and the character of violation of the strong energy condition (SEC). It is shown that it is violated in any static region under the event horizon in such a way that the Tolman mass is negative there. In non-static regions there is constraint of anoth

German Izquierdo, Diego Pavon

Under the assumption that cold dark matter and dark energy interact with each other through a small coupling term, $Q$, we constrain the parameter space of the equation of state $w$ of those dark energy fields whose variation of the field since last scattering do not exceed Planck's mass. We use three parameterizations of $w$ and two different expression

T. Duguet, T. Lesinski, K. Hebeler, A. Schwenk

We perform a systematic study of the odd-even mass staggering generated using a pairing interaction computed at first order in low-momentum interactions. Building on previous work including the (nuclear plus Coulomb) two-nucleon interaction only, we focus here on the first-order contribution from chiral three-nucleon forces. We observe a significant repulsiv

J. M. Poumirol, W. Escoffier, A. Kumar, M. Goiran

We report on magneto-transport measurement in disordered graphene under pulsed magnetic field of up to 57T. For large electron or hole doping, the system displays the expected anomalous Integer Quantum Hall Effect (IQHE) specific to graphene up to filling factor $ν=2$. In the close vicinity of the charge neutrality point, the system breaks up into co-existin