June 2009 arXiv papers — page 32

C. M. Lisse, C. H. Chen, M. C. Wyatt, A. Morlok

The fine dust detected by IR emission around the nearby Beta Pic analogue star HD172555 is very peculiar. The dust mineralogy is composed primarily of highly refractory, non-equilibrium materials, with approximately three-quarters of the Si atoms in silica (SiO2) species. Tektite and obsidian lab thermal emission spectra (non-equilibrium glassy silicas found

Yasuhiro Abe

We define a theory of gravity by constructing a gravitational holonomy operator in twistor space. The theory is a gauge theory whose Chan-Paton factor is given by a trace over elements of Poincaré algebra and Iwahori-Hecke algebra. This corresponds to a fact that, in a spinor-momenta formalism, gravitational theories are invariant under spacetime translation

Tomohiro Matsuda

The delta-N formalism is considered to calculate the evolution of the curvature perturbation in generalized multi-field inflation models. The result is consistent with the usual calculation of the standard kinetic term. For the calculation of the generalized kinetic term, we improved the definition of the adiabatic field. Our calculation improves the usual c

Yasuhiro Abe

We introduce a notion of holonomy in twistor space and construct a holonomy operator by use of a spinor-momenta formalism in twistor space. The holonomy operator gives a monodromy representation of the Knizhnik-Zamolodchikov (KZ) equation, which is mathematically equivalent to a linear representation of a braid group. We show that an S-matrix functional for

S. Chatterjee, R. M. Godbole, Sourendu Gupta

We examine the stability of hadron resonance gas models by extending them to take care of undiscovered resonances through the Hagedorn formula. We find that the influence of unknown resonances on thermodynamics is large but bounded. Hadron resonance gases are internally consistent up to a temperature higher than the cross over temperature in QCD; but by exam

Slava G. Turyshev

Recent experiments have successfully tested Einstein's general theory of relativity to remarkable precision. We discuss recent progress in the tests of relativistic gravity in the solar system and present motivations for the new generation of high-accuracy gravitational experiments. We especially focus on the concepts aiming to probe parametrized-post-Ne

Shunichiro Kittaka, Hiroshi Yaguchi, Yoshiteru Maeno

While the superconducting transition temperature Tc of Sr2RuO4 is 1.5 K, its onset Tc is enhanced as high as 3 K in the Sr2RuO4-Ru eutectic system, which is often referred to as the 3-K phase. We have investigated effects of uniaxial pressure on the non-bulk superconductivity in the 3-K phase. While Tc of pure Sr2RuO4 is known to be suppressed by hydrostatic

Hadi Salmasian

We show that irreducible unitary representations of nilpotent super Lie groups can be obtained by induction from a distinguished class of sub super Lie groups. These sub super Lie groups are natural analogues of polarizing subgroups that appear in classical Kirillov theory. We obtain a concrete geometric parametrization of irreducible unitary representations

C. Bernard, C. DeTar, M. Di Pierro, A. X. El-Khadra

Comparisons of lattice-QCD calculations of semileptonic form factors with experimental measurements often display two sets of points, one each for lattice QCD and experiment. Here we propose to display the output of a lattice-QCD analysis as a curve and error band. This is justified, because lattice-QCD results rely in part on fitting, both for the chiral ex

S. Kittaka, T. Nakamura, Y. Aono, S. Yonezawa

One of the remaining issues concerning the spin-triplet superconductivity of Sr2RuO4 is the strong limit of the in-plane upper critical field Hc2 at low temperatures. In this study, we clarified the dependence of Hc2 on the angle theta between the magnetic field and the ab plane at various temperatures, by precisely and accurately controlling the magnetic fi

C. Emre Koksal, Philip Schniter

To combat the detrimental effects of the variability in wireless channels, we consider cross-layer rate adaptation based on limited feedback. In particular, based on limited feedback in the form of link-layer acknowledgements (ACK) and negative acknowledgements (NAK), we maximize the physical-layer transmission rate subject to an upper bound on the expected

Richard J. Mathar

Baseline calibration of a stellar interferometer is a prerequisite to data reduction of astrometric operations. This technique of astrometry is triangulation of star positions. Since angles are deduced from the baseline and delay side of these triangles, length and pointing direction (in the celestial sphere) of the baseline vector at the time of observation

Cristiano L. Dias, Jens Kroger, Daniel Vernon, Martin Grant

We use molecular dynamics to study the nucleation of cracks in a two dimensional material without pre-existing cracks. We study models with zero and non-zero shear modulus. In both situations the time required for crack formation obeys an Arrhenius law, from which the energy barrier and pre-factor are extracted for different system sizes. For large systems,

Patrick J. Windpassinger, Daniel Oblak, Ulrich B. Hoff, Anne Louchet

We provide a framework for understanding recent experiments on squeezing of a collective atomic pseudo-spin, induced by a homodyne measurement on off-resonant probe light interrogating the atoms. The detection of light decimates the atomic state distribution and we discuss the conditions under which the resulting reduced quantum fluctuations are metrological

C. Bechler, D. Mueller

Based on Regge-inspired arguments and counting rules, we formulate empirical models for zero-skewness generalized parton distributions (GPDs) ${\widetilde H}^{(3)}$ and ${\widetilde E}^{(3)}$ in the iso-vector sector. If a hypothetical $a_1/ρ_2$ master trajectory is taken into account, we find that the polarized deep inelastic structure function $g_1^{(3)}$,

T. de Melo, M. Spreafico

We provide a simple topological derivation of a formula for the Reidemeister and the analityc torsion of spheres.

B. N Barlow, B. H. Dunlap, A. E. Lynas-Gray, J. C. Clemens

We report the discovery of oscillations in the hot subdwarf B star JL 166 from time-series photometry using the Goodman Spectrograph on the 4.1-m Southern Astrophysical Research Telescope. Previous spectroscopic and photometric observations place the star near the hot end of the empirical sdB instability strip and imply the presence of a cool companion. Ampl

Idris Kharroubi, Huyen Pham

We study the optimal portfolio liquidation problem over a finite horizon in a limit order book with bid-ask spread and temporary market price impact penalizing speedy execution trades. We use a continuous-time modeling framework, but in contrast with previous related papers (see e.g. [24] and [25]), we do not assume continuous-time trading strategies. We con

S. Ehlert, M. P. Ulmer

Using archival Chandra and XMM-Newton data on 35 galaxy clusters, we measured average temperature and metallicity profiles for clusters based separated by temperature, cooling time, and redshift. Our results show no evidence for significant changes in the metallicity or temperature profiles with redshift once these selection effects are taken into account.

D. Villuendas, D. Gheorghe, A. Hernández-Mínguez, F. Macià

For the first time, the morphology and dynamics of spin avalanches in Mn12-Acetate crystals using magneto-optical imaging has been explored. We observe an inhomogeneous relaxation of the magnetization, the spins reversing first at one edge of the crystal and a few milliseconds later at the other end. Our data fit well with the theory of magnetic deflagration

Dirk Helbing

This contribution replies to H. M. Zhang's paper "What Faster-than-traffic Characteristic Speeds Mean for Vehicular Traffic Flow", which comments on the manuscript "On the Controversy around Daganzo's Requiem for and Aw-Rascle's Resurrection of Second-Order Traffic Flow Models" published in this issue of Eurpean Physical Journal B

Hamed Daneshpajouh, Hamid Reza Daneshpajouh, Farzad Didehvar

In this paper we offer a metric similar to graph edit distance which measures the distance between two (possibly infinite)weighted graphs with finite norm (we define the norm of a graph as the sum of absolute values of its edges). The main result is the completeness of the space. Some other analytical properties of this space are also investigated. The intro

Antonio C. Gutiérrez-Piñeres, Guillermo A. González, Viviana M. Viña-Cervantes

A new family of exact solutions of the Einstein-Maxwell equations for static axially symmetric spacetimes is presented. The metric functions of the solutions are explicitely computed and are simply written in terms of the oblate spheroidal coordinates. The solutions, obtained by applying the Ernst method of complex potentials, describe an infinite family of

M. S. Madjarska, T. Wiegelmann

We aim at studying the small-scale evolution at the boundaries of an equatorial coronal hole connected with a channel of open magnetic flux with the polar region and an `isolated' one in the extreme-ultraviolet spectral range. We intend to determine the spatial and temporal scale of these changes. Imager data from TRACE in the Fe IX/X 171 A passband and

Michael Crampin

This paper is a study of the relationship between two constructions associated with Cartan geometries, both of which involve Lie algebroids: the Cartan algebroid, due to [Blaom A.D., Trans. Amer. Math. Soc. 358 (2006), 3651-3671], and tractor calculus [Cap A., Gover A.R., Trans. Amer. Math. Soc. 354 (2001), 1511-1548].

Blanca Biel, François Triozon, X. Blase, Stephan Roche

We report a first-principles based study of mesoscopic quantum transport in chemically doped graphene nanoribbons with a width up to 10 nm. The occurrence of quasibound states related to boron impurities results in mobility gaps as large as 1 eV, driven by strong electron-hole asymmetrical backscattering phenomena. This phenomenon opens new ways to overcome

Tapan Mishra, Ramesh V. Pai, B. P. Das

It is well known that the supersolid form of matter can arise in a single species of cold bosonic atoms in an optical lattice due to long range interactions. We present a scenario where a supersolid is induced in one of the components of a mixture of two species bosonic atoms where there is no long range interactions. We study a system of normal and hardcore

Yuriy A. Kosevich, Alexander V. Savin

We present analytical model and molecular dynamics simulations of phonon heat transport in nanowires and nanoribbons with anharmonic lattices and dynamically rough surfaces and edges. In agreement with recent experiments on heat transport in single-crystalline silicon nanowires with rough surfaces, our model and simulations predict finite and length-independ

M. S. Madjarska, J. G. Doyle, B. de Pontieu

The solar atmosphere contains a wide variety of small-scale transient features. Here, we explore the inter-relation between some of them such as surges, explosive events and blinkers via simultaneous spectral and imaging data taken with the TRACE imager, the SUMER, and CDS spectrometers on board SoHO, and SVST La Palma. The alignment of all data both in time

Benoit Jacob

Hessenberg decomposition is the basic tool used in computational linear algebra to approximate the eigenvalues of a matrix. In this article, we generalize Hessenberg decomposition to continuous matrix fields over topological spaces. This works in great generality: the space is only required to be normal and to have finite covering dimension. As applications,

M. Bouamra, S. Hassani, J. -M. Maillard

We consider some two-dimensional birational transformations. One of them is a birational deformation of the Hénon map. For some of these birational mappings, the post critical set (i.e. the iterates of the critical set) is infinite and we show that this gives straightforwardly the algebraic covariant curves of the transformation when they exist. These covari

Ahmet Kara, Martin Lange, Thomas Schwentick, Volker Weber

The paper studies the expressivity, relative succinctness and complexity of satisfiability for hybrid extensions of the branching-time logics CTL and CTL+ by variables. Previous complexity results show that only fragments with one variable do have elementary complexity. It is shown that H1CTL+ and H1CTL, the hybrid extensions with one variable of CTL+ and CT

Neil Trentham, Brent Tully

We present a compilation of galaxies in the NGC 1023 Group, an accumulation of late-type galaxies at a distance of 10 Mpc. Members at high and intermediate luminosities were identified from their spectroscopic velocities. Members at low luminosities were identified from their morphologies on wide-field CCD images. The faint-end slope is in the range -1.27 <

Fardin Kheirandish, S. Javad Akhtarshenas, Hamidreza Mohammadi

The effects of initial conditions and system parameters on entanglement dynamics and asymptotic entanglement for a two-qubit anisotropic XY Heisenberg system in the presence of an inhomogeneous magnetic field and spin-orbit interaction are investigated. We suppose that each qubit interacts with a separate thermal reservoir which is held in its own temperatur

Bernhard Mieck

Coherent state path integrals are applied to a many-body problem for non-relativistic electrons in a central potential and an external magnetic field; however, in comparison to previous coherent state path integrals, we definitely fix the symmetry quantum numbers to specific values with second quantized field operators which are restricted by delta functions

Bernhard Mieck

A coherent state path integral is considered for fermions with precise, discrete time separation. We derive in detail a nonlinear sigma model of a pair condensate concerning the precise, discrete time step order which is usually abbreviated by the appealing (but in fact non-existent) hermitian form of the fields. This problem is ubiquitous in quantum many-bo

David L. Donoho, Jared Tanner

We review connections between phase transitions in high-dimensional combinatorial geometry and phase transitions occurring in modern high-dimensional data analysis and signal processing. In data analysis, such transitions arise as abrupt breakdown of linear model selection, robust data fitting or compressed sensing reconstructions, when the complexity of the

Hannu Paukkunen

This is the introductory part of my PhD thesis which consists of two parts, the separate introduction and four published articles. The introduction begins by a technically detailed description of the DGLAP evolution and the fast numerical solving method for the DGLAP equations, which has been used in the numerical works of the published articles of this thes

Sean A. Hayward

Eight different refinements of trapped surfaces are proposed, of three basic types, each intended as potential stability conditions. Minimal trapped surfaces are strictly minimal with respect to the dual expansion vector. Outer trapped surfaces have positivity of a certain curvature, related to surface gravity. Increasingly (future, respectively past) trappe

Bernhard Mieck

The integrable, (1+1) Gross-Pitaevskii (GP-) equation with hermitian property is extended to chaotic behaviour as part of general complex fields within the sl(2,C) algebra for Lax pairs. Furthermore, we prove the involution property of conserved quantities in the case of GP-type equations with an arbitrary external potential. We generalize the approach of La

Volker Weber

We classify the complexity of the satisfiability problem for extensions of CTL and UB. The extensions we consider are Boolean combinations of path formulas, fairness properties, past modalities, and forgettable past. Our main result shows that satisfiability for CTL with all these extensions is still in 2-EXPTIME, which strongly contrasts with the nonelement

A. Belabbas

The subject of this dissertation consists in analyzing a recent proposition, advanced by C.C.Barros, in which the non gravitational interactions can affect the space-time metric as in gravity. In fact, in the context of the Schwarzschild solution, the hydrogen atom is described in a completely new way : instead of following the usual approach to describe the

Takayuki Miyadera, Masakazu Yoshida, Hideki Imai

We discuss the Ping-Pong protocol which was proposed by Bostroem and Felbinger. We derive a simple trade-off inequality between distinguishability of messages for Eve and detectability of Eve for legitimate users. Our inequality holds for arbitrary initial states. That is, even if Eve prepares an initial state, she cannot distinguish messages without being d

Paul T. Allen, Alan D. Rendall

In cosmology an important role is played by homogeneous and isotropic solutions of the Einstein-Euler equations and linearized perturbations of these. This paper proves results on the asymptotic behaviour of scalar perturbations both in the approach to the initial singularity of the background model and at late times. The main equation of interest is a linea

Waheb Bishara, Chetan Nayak

We compute the effect of Landau-level-mixing on the effective two-body and three-body pseudopotentials for electrons in the lowest and second Landau levels. We find that the resulting effective three-body interaction is attractive in the lowest relative angular momentum channel. The renormalization of the two-body pseudopotentials also shows interesting stru

Pietro Fré, Pietro Antonio Grassi, Luca Sommovigo, Mario Trigiante

We study the dualities for sigma models with fermions and bosons. We found that the generalization of the SO(m,m) duality for D=2 sigma models and the Sp(2n) duality for D=4 sigma models is the orthosymplectic duality OSp(m,m|2 n). We study the implications of this and we derive the most general D=2 sigma model, coupled to fermionic and bosonic one-forms, wi

Ruihu Li, Zongben Xu

For each odd prime power $q$, let $4 \leq n\leq q^{2}+1$. Hermitian self-orthogonal $[n,2,n-1]$ codes over $GF(q^{2})$ with dual distance three are constructed by using finite field theory. Hence, $[[n,n-4,3]]_{q}$ quantum MDS codes for $4 \leq n\leq q^{2}+1$ are obtained.

Stephen P. Jordan

In topological quantum computation the geometric details of a particle trajectory are irrelevant; only the topology matters. Taking this one step further, we consider a model of computation that disregards even the topology of the particle trajectory, and computes by permuting particles. Whereas topological quantum computation requires anyons, permutational

Katsunori Kawamura

The direct sum ${\cal O}_{*}$ of all Cuntz algebras has a non-cocommutative comultiplication $Δ_φ$ such that there exists no antipode of any dense subbialgebra of the C$^{*}$-bialgebra $({\cal O}_{*},Δ_φ)$. From states equations of ${\cal O}_{*}$ with respect to the tensor product, we construct an operator $W$ for $({\cal O}_{*},Δ_φ)$ such that $W^{*}$ is an

Christoph G. Salzmann, Paolo G. Radaelli, Erwin Mayer, John L. Finney

A new phase of ice, named ice XV, has been identified and its structure determined by neutron diffraction. Ice XV is the hydrogen-ordered counterpart of ice VI and is thermodynamically stable at temperatures below ~130 K in the 0.8 to 1.5 GPa pressure range. The regions of stability in the medium pressure range of the phase diagram have thus been finally map

Alessandro Cosentino, Simone Severini

We prove a connection between Schmidt-rank and weight of quadratic forms. This provides a new tool for the classification of graph states based on entanglement. Our main tool arises from a reformulation of previously known results concerning the weight of quadratic forms in terms of graph states properties. As a byproduct, we obtain a straightforward charact

Chiu Fan Lee

We carry out a theoretical study on the isotropic-nematic phase transition and phase separation in amyloid fibril solutions. Borrowing the thermodynamic model employed in the study of cylindrical micelles, we investigate the variations in the fibril length distribution and phase behavior with respect to changes in the protein concentration, fibril&#39;s rigi

J. M. Campbell, E. Castaneda-Miranda, Y. Fang, N. Kauer

The production of two weak bosons at the Large Hadron Collider will be one of the most important sources of SM backgrounds for final states with multiple leptons. In this paper we consider several quantities that can help normalize the production of weak boson pairs. Ratios of inclusive cross-sections for production of two weak bosons and Drell-Yan are inves

Christopher Hillar, Luis Garcia-Puente, Abraham Martin del Campo, James Ruffo

We describe a general framework for large-scale computational experiments in mathematics using computer resources that are available in most mathematics departments. This framework was developed for an experiment that is helping to formulate and test conjectures in the real Schubert calculus. Largely using machines in instructional computer labs during off-h

Walter D. Neumann

We give short expositions of both Leighton&#39;s proof and the Bass-Kulkarni proof of Leighton&#39;s graph covering theorem, in the context of colored graphs. We discuss a further generalization, needed elsewhere, to &#34;symmetry-restricted graphs.&#34; We can prove it in some cases, for example, if the &#34;graph of colors&#34; is a tree, but we do not kno

Frederic Rousset, Nikolay Tzvetkov

We prove the linear and nonlinear instability of the water line solitary waves with respect to transverse perturbations.

C. Deibel, T. Strobel, V. Dyakonov

The separation of photogenerated polaron pairs in organic bulk heterojunction solar cells is the intermediate but crucial step between exciton dissociation and charge transport to the electrodes. In state-of-the-art devices, above 80% of all polaron pairs are separated at fields of below $10^7$V/m. In contrast, considering just the Coulomb binding of the pol

Fl. Stancu

In this exploratory study the spectrum of tetraquarks of type $c \bar c s \bar s$ is calculated within a simple quark model with chromomagnetic interaction and effective quark masses extracted from meson and baryon spectra. It is tempting to see if this spectrum can accommodate the resonance Y(4140), observed by the CDF collaboration, but not yet confirmed.

John Garnett, Rowan Killip, Raanan Schul

For $d\geq 2$, we construct a doubling measure $ν$ on $\R^d$ and a rectifiable curve $Γ$ such that $ν(Γ)>0$.

V. M. Red&#39;kov

Some facts of the theory of the Lorentz group are specified for looking at the problems of light polarization optics in the frames of vector Stokes-Mueller and spinor Jones formalism. In view of great differences between properties of isotropic and time-like vectors in Special Relativity we should expect principal differences in describing completely polariz

S. Paul Smith

Let R be the free algebra on x and y modulo the relations x^5=yxy and y^2=xyx endowed with the grading deg x=1 and deg y=2. Let B_3 denote the blow up of the projective plane at three non-colliear points. The main result in this paper is that the category of quasi-coherent sheaves on B_3 is equivalent to the quotient of the category of graded R-modules modul

I. B. Khriplovich, D. L. Shepelyansky

We study the capture of galactic dark matter by the Solar System. The effect is due to the gravitational three-body interaction between the Sun, one of the planets, and a dark matter particle. The analytical estimate for the capture cross-section is derived and the upper and lower bounds for the total mass of the captured dark matter particles are found. The

G. Militaru

We call a monoidal category ${\mathcal C}$ a Serre category if for any $C$, $D \in {\mathcal C}$ such that $C\ot D$ is semisimple, $C$ and $D$ are semisimple objects in ${\mathcal C}$. Let $H$ be an involutory Hopf algebra, $M$, $N$ two $H$-(co)modules such that $M \otimes N$ is (co)semisimple as a $H$-(co)module. If $N$ (resp. $M$) is a finitely generated p

C. Arezzo, A. Della Vedova, G. La Nave

In this paper we extend the notion of Futaki invariant to big and nef classes in such a way that it defines a continuous function on the \K\ cone up to the boundary. We apply this concept to prove that reduced normal crossing singularities are sufficient to check $K$-semistability. A similar improvement on Donaldson's lower bound for Calabi energy is given.

Wei Han, Shi-Yuan Li, Yong-Hui Shang, Feng-Lan Shao

The philosophy on production of exotic hadrons (multi-quark states) in the framework of quark combination model is investigated, taking $f_0(980)$ as an example. The production rate and $p_T$ spectra of $f_0(980)$ considered as $(s\bar s)$ or $(s\bar q\bar s q)$ respectively, are calculated and compared in Au+Au collisions at $\sqrt{s_{NN}}=200GeV$. The unit

Salvatore Mandra&#39;, Santo Fortunato, Claudio Castellano

We study the coevolution of a generalized Glauber dynamics for Ising spins, with tunable threshold, and of the graph topology where the dynamics takes place. This simple coevolution dynamics generates a rich phase diagram in the space of the two parameters of the model, the threshold and the rewiring probability. The diagram displays phase transitions of dif

I. Thongkool, M. Sami, R. Gannouji, S. Jhingan

The $f(R)$ gravity models proposed by Hu-Sawicki and Starobinsky are generic for local gravity constraints to be evaded. The large deviations from these models either result into violation of local gravity constraints or the modifications are not distinguishable from cosmological constant. The curvature singularity in these models is generic but can be avoid

Michael Hutchings

This is an introduction to Taubes&#39;s proof of the Weinstein conjecture, written for the AMS Current Events Bulletin. It is intended to be accessible to nonspecialists, so much of the article is devoted to background and context.

S. Wakimoto, K. Kodama, M. Ishikado, M. Matsuda

Low energy spin fluctuations are studied for the electron-doped Fe-based superconductor LaFeAsO(1-x)F(x) by inelastic neutron scattering up to the energy transfer of w = 15 meV using polycrystalline samples. Superconducting samples (x=0.057, Tc=25 K and x=0.082, Tc=29 K) show dynamical spin susceptibility chi&#34;(w) almost comparable with the parent sample&

Marc-André Laverdière, Serguei A. Mokhov, Suhasini Tsapa, Djamel Benredjem

The purpose of this work is to design and implement a plugin-based environment that allows to integrate forensic tools working together to support programming tasks and addition of new tools. Integration is done through GUI components. The end-system environment must have user friendly GUI, configuration capabilities, plug-in capabilities to insert/inject ne

Marc-André Laverdière, Serguei A. Mokhov, Suhasini Tsapa, Djamel Benredjem

The purpose behind this article is to describe the features of Ftklipse, an extendable platform for computer forensics. This document designed to provide a detailed specification for the developers of Ftklipse. Ftklipse is a thick-client solution for forensics investigation. It is designed to collect and preserve evidence, to analyze it and to report on it.

Xin-Bing Huang

It appears natural to consider the four dimensional relativistic massive field as a five dimensional massless field. If the fifth coordinate is interpreted as the proper time, then the fifth moment can be understood as the rest mass. After introducing the rest mass operator, we define the mass eigenstate and the nonmass eigenstate. The general equations of s

Luc Ceuppens, Alan Sardella, Daniel Kharitonov

Drawing from todays best-in-class solutions, we identify power-saving strategies that have succeeded in the past and look forward to new ideas and paradigms. We strongly believe that designing energy-efficient network equipment can be compared to building sports cars, task-oriented, focused and fast. However, unlike track-bound sports cars, ultra-fast and pu

Ed Lee, M. E. Brachet, A. Pouquet, P. D. Mininni

Using computations of three-dimensional magnetohydrodynamic (MHD) turbulence with a Taylor-Green flow, whose inherent time-independent symmetries are implemented numerically, and in the absence of either a forcing function or an imposed uniform magnetic field, we show that three different inertial ranges for the energy spectrum may emerge for three different

Jeremy Bernstein

The subject of uranium isotope separation by the use of gas cenrifuges is a very active one. I present the physics of this process and some of its history.

Jakub Mielczarek, Orest Hrycyna, Marek Szydlowski

In this paper we study dynamics of the closed FRW model with holonomy corrections coming from loop quantum cosmology. We consider models with a scalar field and cosmological constant. In case of the models with cosmological constant and free scalar field, dynamics reduce to 2D system and analysis of solutions simplify. If only free scalar field is included t

Noushine Shahidzadeh Bonn, Francois Bertrand, Daniel Bonn

We investigate salt crystallization in porous media that can lead to their disintegration. For sodium sulfate we show for the first time experimentally that when anhydrous crystals are wetted with water, there is very rapid growth of the hydrated form of sulfate in clusters that nucleate on anhydrous salt micro crystals. The molar volume of the hydrated crys

Juan Belmonte-Beitia, Dmitry Pelinovsky

We address the Gross--Pitaevskii (GP) equation with a periodic linear potential and a periodic sign-varying nonlinearity coefficient. Contrary to the claims in the previous works of Abdullaev {\em et al.} [PRE {\bf 77}, 016604 (2008)] and Smerzi & Trombettoni [PRA {\bf 68}, 023613 (2003)], we show that the intersite cubic nonlinear terms in the discrete nonl

R. Neilson, F. LePort, A. Pocar, K. Kumar

EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of scintillation light in an ultra-low-background liquid xenon (LXe) detector. We describe initial measurements of dark noise, gain and response to xenon scintillation light of LAAPDs at temperatures from room temperature to 169K - the temperature of liquid xenon. We also describe the i

Alejandro B. Kolton, Gregory Schehr, Pierre Le Doussal

We study the non-stationary dynamics of an elastic interface in a disordered medium at the depinning transition. We compute the two-time response and correlation functions, found to be universal and characterized by two independent critical exponents. We find a good agreement between two-loop Functional Renormalization Group calculations and molecular dynami

F. Combes, A. J. Baker, E. Schinnerer, S. Garcia-Burillo

We present high-resolution CO(1-0) and CO(2-1) maps of the LINER 2 galaxy NGC1961. This galaxy is unusual among late-type (Sc) disk galaxies in having a very large radial extent and inferred dynamical mass. We propose a head-on collision scenario to explain the perturbed morphology of this galaxy- both the off-centered rings and the inflated radius. This sce

O. E. Peil, A. V. Ruban, B. Johansson

An archetypical spin-glass metallic alloy, Cu0.83Mn0.17, is studied by means of an ab-initio based approach. First-principles calculations are employed to obtain effective chemical, strain-induced and magnetic exchange interactions, as well as static atomic displacements, and the interactions are subsequently used in thermodynamic simulations. It is shown th

Oskar Vafek, Kun Yang

Low-energy electronic structure of (unbiased) bilayer graphene is made of two Fermi points with quadratic dispersions, if trigonal-warping and other high order contributions are ignored. We show that as a result of this qualitative difference from single-layer graphene, short-range (or screened Coulomb) interactions are marginally relevant. We use renormaliz

The HERMES Collaboration, A. Airapetian

The first direct measurement of the dependence on target nuclear mass of the average squared transverse momentum <pt**2> of pi+, pi-, and K+ mesons from deep-inelastic lepton scattering is obtained as a function of several kinematic variables. The data were accumulated at the HERMES experiment at DESY, in which the HERA 27.6 GeV lepton beam was scattered off

Rogério Reis, Nelma Moreira, Marco Almeida

We give an unique string representation, up to isomorphism, for initially connected deterministic finite automata (ICDFAs) with n states over an alphabet of k symbols. We show how to generate all these strings for each n and k, and how its enumeration provides an alternative way to obtain the exact number of ICDFAs.

Y. -T. Cui, G. Finocchio, C. Wang, J. A. Katine

We report single-shot measurements of resistance versus time for thermally assisted spin-torque-driven switching in magnetic tunnel junctions. We achieve sufficient sensitivity to resolve the resistance signals leading up to switching, including the variations between individual switching events. Analyses of pre-switching thermal fluctuations allow detailed

Steven P. Kerckhoff, Peter A. Storm

Let W be a compact hyperbolic n-manifold with totally geodesic boundary. We prove that if n>3 then the holonomy representation of pi_1 (W) into the isometry group of hyperbolic n-space is infinitesimally rigid.

Arnau Mir, Francesc Rossello

The path-difference metric is one of the oldest distances for the comparison of fully resolved phylogenetic trees, but its statistical properties are still quite unknown. In this paper we compute the mean value of the square of the path-difference metric between two fully resolved rooted phylogenetic trees with $n$ leaves, under the uniform distribution. Thi

B. Neethi Simon, Sudhavathani Simon, F. Gori, Massimo Santarsiero

The issue raised in this paper is classical in the sense of being ancient: which subset of 4X4 matrices should be accepted as physical Mueller matrices in polarization optics? Non-quantum entanglement between the polarization and spatial degrees of freedom of an electromagnetic beam is shown to provide the physical basis to resolve this issue in a definitive

Chandra Chekuri, Iftah Gamzu

An important research thread in algorithmic game theory studies the design of efficient truthful mechanisms that approximate the optimal social welfare. A fundamental question is whether an α-approximation algorithm translates into an α-approximate truthful mechanism. It is well-known that plugging an α-approximation algorithm into the VCG technique may not

Vesselin Petkov, Luchezar Stoyanov

An obstacle $K \subset \R^n,\: n \geq 3,$ $n$ odd, is called trapping if there exists at least one generalized bicharacteristic $γ(t)$ of the wave equation staying in a neighborhood of $K$ for all $t \geq 0.$ We examine the singularities of the scattering kernel $s(t, θ, ω)$ defined as the Fourier transform of the scattering amplitude $a(λ, θ, ω)$ related to

Rajesh Singh, Mukesh Kumar, Manoj K. Chaudhary, Florentin Smarandache

This paper considers the problem of estimating the population mean using information on auxiliary variable in presence of non response. Exponential ratio and exponential product type estimators have been suggested and their properties are studied. An empirical study is carried out to support the theoretical results.

Erik D. Demaine, Martin L. Demaine, Vi Hart, John Iacono

We construct the first two continuous bloomings of all convex polyhedra. First, the source unfolding can be continuously bloomed. Second, any unfolding of a convex polyhedron can be refined (further cut, by a linear number of cuts) to have a continuous blooming.

Vit Niennattrakul, Pongsakorn Ruengronghirunya, Chotirat Ann Ratanamahatana

Among many existing distance measures for time series data, Dynamic Time Warping (DTW) distance has been recognized as one of the most accurate and suitable distance measures due to its flexibility in sequence alignment. However, DTW distance calculation is computationally intensive. Especially in very large time series databases, sequential scan through the

Fariel Shafee

We review a new form of entropy suggested by us, with origin in mixing of states of systems due to interactions and deformations of phase cells. It is demonstrated that this nonextensive form also leads to asymmetric maximal entropy configurations unlike Shannon entropy. We discuss how, beginning with quantum entanglement of microsystems with one another and

V. F. Cardone, A. Del Popolo, P. Kroupa

Early - type galaxies (ETGs) define a narrow strip in the size - mass plane because of the observed correlation between the effective radius $R_{eff}$ and the total stellar mass $M_{\star}$. When expressed in logarithmic units, a linear relation, $\log{R_{eff}} \propto γ\log{M_{\star}}$, is indeed observationally found, but the slope $γ$ deviates from the ca

T. P. Yu, M. Chen, A. Pukhov

We study proton acceleration from a foil target with a transversely varying density using multi-dimensional Particle-in-Cell (PIC) simulations. In order to reduce electron heating and deformation of the target, circularly polarized Gaussian laser pulses at intensities of the order of 1022Wcm-2 are used. It is shown that when the target density distribution f

Kazuto Oshima

We study concretely how classical signals should be processed in quantum cluster-state computation. Deforming corresponding quantum teleportation circuit, we find a simple rule of a classical signal-flow to obtain correct quantum computation results.

Liaofu Luo

The importance of torsion vibration in the transmission of life information is indicated. The localization of quantum torsion state is proved. Following these analyses a formalism on the quantum theory of conformation-electron system is proposed. The conformational-electronic transition is calculated by non-adiabatic operator method. The protein folding is v

S. K. Mathew, V. Zakharov, S. K. Solanki

The contrasts of features in the quiet Sun are studied using filtergrams recorded by the Broad-band Filter Imager on the Hinode/Solar Optical Telescope. In a first step, the scattered light originating in the instrument is modeled using Mercury transit data. Combinations of four two-dimensional Gaussians with different widths and weights were employed to ret