March 2008 arXiv papers — page 25

Eugene V. Petrov

In this paper we consider smooth oriented hypersurfaces in 2-step nilpotent Lie groups with a left invariant metric and derive an expression for the Laplacian of the Gauss map for such hypersurfaces in the general case and in some particular cases. In the case of CMC-hypersurface in the (2m+1)-dimensional Heisenberg group we also derive necessary and suffici

Andrew J. Duncan, Ilya V. Kazachkov, Vladimir N. Remeslennikov

The goal of this paper is to construct and describe certain arithmetic subgroups of the automorphism group of a partially commutative group. More precisely, given an arbitrary finite graph $Γ$ we construct an arithmetic subgroup $St(L(G))$, represented as a subgroup of $GL(n,Z)$, where $n$ is the number of vertices of the graph $Γ$. In the last section of th

Armengol Gasull, Hector Giacomini

We give an effective method for controlling the maximum number of limit cycles of some planar polynomial systems. It is based on a suitable choice of a Dulac function and the application of the well-known Bendixson-Dulac Criterion for multiple connected regions. The key point is a new approach to control the sign of the functions involved in the criterion. T

G. Bono, A. Calamida, C. E. Corsi, P. B. Stetson

We present deep and accurate Near-Infrared (NIR) photometry of the Galactic Globular Cluster (GC) Omega Cen. Data were collected using the Multi-Conjugate Adaptive Optics Demonstrator (MAD) on VLT (ESO). The unprecedented quality of the images provided the opportunity to perform accurate photometry in the central crowded regions. Preliminary results indicate

J. Dukelsky, G. Ortiz

We discuss the concept of Cooper pair in the context of recent experimental studies of radio-frequency excitations in ultracold atomic gases. We argue that the threshold energy determines the size of the Cooper pair emergent from the exact solution of the reduced BCS problem, and elaborate on the physical distinction between bosonic and fermionic Cooper pair

Peter Mohr

Properties of intermediate mass nuclei have been investigated within the framework of the alpha-cluster model in combination with systematic double-folding potentials. Previously, this alpha-cluster model has been widely applied to light nuclei, in particular to 8Be = alpha \otimes alpha, 20Ne = 16O \otimes alpha, and 44Ti = 40Ca \otimes alpha, and to heavy

Gur Yaari, Andrzej Nowak, Kamil Rakocy, Sorin Solomon

P.W. Anderson proposed the concept of complexity in order to describe the emergence and growth of macroscopic collective patterns out of the simple interactions of many microscopic agents. In the physical sciences this paradigm was implemented systematically and confirmed repeatedly by successful confrontation with reality. In the social sciences however, th

Evgeny Korotyaev, Pavel Kargaev

We consider the periodic Zakharov-Shabat operators on the real line. The spectrum of this operator consists of intervals separated by gaps with the lengths $|g_n|\ge 0, n\in \Z$. Let $\m_n^\pm$ be the corresponding effective masses and let $h_n$ be heights of the corresponding slits in the quasimomentum domain. We obtain a priori estimates of sequences $g=(|

Michail Anthropelos, Gordan Zitkovic

We consider two risk-averse financial agents who negotiate the price of an illiquid indivisible contingent claim in an incomplete semimartingale market environment. Under the assumption that the agents are exponential utility maximizers with non-traded random endowments, we provide necessary and sufficient conditions for negotiation to be successful, i.e., f

A. Kaboth, J. Monroe, S. Ahlen, D. Dujmic

This paper presents a measurement of the ratio of photon to electron production and the scintillation spectrum in a popular gas for time pro jection chambers, carbon tetrafluoride (CF4), over the range of 200 to 800 nm; the ratio is measured to be 0.34+/-0.04. This result is of particular importance for a new generation of dark matter time projection chamber

Yu-Huei Wu, Chih-Hung Wang

In general relativity, quasi-local energy-momentum expressions have been constructed from various formulae. However, Newtonian theory of gravity gives a well known and an unique quasi-local mass expression (surface integration). Since geometrical formulation of Newtonian gravity has been established in the covariant Newtonian space-time, it provides a covari

R. Crane, D. Sornette

We study the relaxation response of a social system after endogenous and exogenous bursts of activity using the time-series of daily views for nearly 5 million videos on YouTube. We find that most activity can be described accurately as a Poisson process. However, we also find hundreds of thousands of examples in which a burst of activity is followed by an u

C. Bocci, F. Cools

Let T be a weighted tree with n numbered leaves and let D be its distance matrix, so D(i,j) is the distance between the leaves i and j. If m is an integer between 2 and n, we prove a tropical formula to compute the m-dissimilarity map of T (i.e. the weights of the subtrees of T with m leaves), given D. For m equal to 3, we present a tropical description of t

G. Y. Liang, G. Zhao, J. Y. Zhong, Y. T. Li

Rich soft X-ray emission lines of highly charged silicon ions (Si VI--Si XII) were observed by irradiating an ultra-intense laser pulse with width of 200 fs and energy of $\sim$90 mJ on the solid silicon target. The high resolution spectra of highly charged silicon ions with full-width at half maximum (FWHM) of $\sim$0.3--0.4Åis analyzed in wavelength range

Allan Gut, Ulrich Stadtmüller

We extend a law of the single logarithm for delayed sums by Lai to delayed sums of random fields. A law for subsequences, which also includes the one-dimensional case, is obtained in passing.

Yi-Cheng Zhang, Marcel Blattner, Yi-Kuo Yu

Using heat conduction mechanism on a social network we develop a systematic method to predict missing values as recommendations. This method can treat very large matrices that are typical of internet communities. In particular, with an innovative, exact formulation that accommodates arbitrary boundary condition, our method is easy to use in real applications

Frank Winter, Wolfhard Janke, Adriaan M. J. Schakel

The fractal structure of high-temperature graphs of the three-dimensional Ising and XY models is investigated by simulating these graphs directly on a cubic lattice and analyzing them with the help of percolation observables. The Ising graphs are shown to percolate right at the Curie critical point. The diverging length scale relevant to the graphs in the vi

Jorn Foros, Arne Brataas, Yaroslav Tserkovnyak, Gerrit E. W. Bauer

In the presence of spatial variation of the magnetization direction, electric current noise causes a fluctuating spin-transfer torque that increases the fluctuations of the ferromagnetic order parameter. By the fluctuation-dissipation theorem, the equilibrium fluctuations are related to the magnetization damping, which in non-uniform ferromagnets acquires a

Mirela Damian, Saurav Pandit, Sriram Pemmaraju

This paper presents a distributed algorithm on wireless ad-hoc networks that runs in polylogarithmic number of rounds in the size of the network and constructs a linear size, lightweight, (1+ε)-spanner for any given ε> 0. A wireless network is modeled by a d-dimensional α-quasi unit ball graph (α-UBG), which is a higher dimensional generalization of the stan

Dirk Frettlöh

Two results about equidistribution of tile orientations in primitive substitution tilings are stated, one for finitely many, one for infinitely many orientations. Furthermore, consequences for the associated diffraction spectra and the dynamical systems are discussed.

Bo Li, Marc G. Genton, Michael Sherman

We study the asymptotic joint distribution of sample space--time covariance estimators of strictly stationary random fields. We do this without any marginal or joint distributional assumptions other than mild moment and mixing conditions. We consider several situations depending on whether the observations are regularly or irregularly spaced and whether one

Constantinos Kardaras

We provide equivalence of numerous no-free-lunch type conditions for financial markets where the asset prices are modeled as exponential Levy processes, under possible convex constraints in the use of investment strategies. The general message is the following: if any kind of free lunch exists in these models it has to be of the most egregious type, generati

M. Hudaverdi, E. N. Ercan, A. Mert-Ankar, F. Gok

We analyzed the data for the nearby cluster of galaxies Abell 2255 from archival XMM-Newton observations in order to search for the properties of X-ray point like structures in the outskirts. 11 point-like X-ray emission is detected. Detected X-ray sources are then observed with the 1.5 meter RTT-150 at Turkish National Observatory for possible optical count

Guillaume Beuf

A new type of approximate scaling compatible with the Balitsky-Kovchegov equation with running coupling is found, which is different from the previously known running coupling geometric scaling. The corresponding asymptotic traveling wave solution is derived. Although featuring different scaling behaviors, the two solutions are complementary approximations o

John H. J. Einmahl, Amélie Fils-Villetard, Armelle Guillou

We investigate the estimation of the extreme value index when the data are subject to random censorship. We prove, in a unified way, detailed asymptotic normality results for various estimators of the extreme value index and use these estimators as the main building block for estimators of extreme quantiles. We illustrate the quality of these methods by a sm

Ph. Boucaud, J. P. Leroy, A. Le Yaouanc, J. Micheli

We examine analytically the ghost propagator Dyson-Schwinger Equation (DSE) in the deep IR regime and prove that a finite ghost dressing function at vanishing momentum is an alternative solution (solution II) to the usually assumed divergent one (solution I). We furthermore find that the Slavnov-Taylor identities discriminate between these two classes of sol

Marc Deleglise, Jean-Louis Nicolas, Paul Zimmermann

Let ${\mathfrak S}_n$ denote the symmetric group with $n$ letters, and $g(n)$ the maximal order of an element of ${\mathfrak S}_n$. If the standard factorization of $M$ into primes is $M=q_1^{\al_1}q_2^{\al_2}... q_k^{\al_k}$, we define $\ell(M)$ to be $q_1^{\al_1}+q_2^{\al_2}+... +q_k^{\al_k}$; one century ago, E. Landau proved that $g(n)=\max_{\ell(M)\le n

Dominique Durand

An event generator for the description of nuclear reactions in the Fermi energy range is briefly introduced and first comparisons with experimental data are shown.

Maicon S. Faria, N. S. Branco, M. H. R. Tragtenberg

We study the spin-1/2 Ising model on a Bethe lattice in the mean-field limit, with the interaction constants following two deterministic aperiodic sequences: Fibonacci or period-doubling ones. New algorithms of sequence generation were implemented, which were fundamental in obtaining long sequences and, therefore, precise results. We calculate the exact crit

Bjoern Malte Schaefer, Gabriela Alejandra Caldera-Cabral, Roy Maartens

We consider a phenomenological model for a coupling between the dark matter and dark energy fluids and investigate the sensitivity of a weak lensing measurement for constraining the size of this coupling term. Physically, the functional form of the coupling term in our model describes the decay of dark matter into dark energy. We present forecasts for tomogr

F. Svensson, S. Jonsell, C. M. Dion

We extend the theory for laser cooling in a near-resonant optical lattice to include multiple excited hyperfine states. Simulations are performed treating the external degrees of freedom of the atom, i.e., position and momentum, classically, while the internal atomic states are treated quantum mechanically, allowing for arbitrary superpositions. Whereas theo

R. Swirkowicz, M. Wilczynski, J. Barnas

Spin-polarized transport through a quantum dot strongly coupled to ferromagnetic electrodes with non-collinear magnetic moments is analyzed theoretically in terms of the non-equilibrium Green function formalism. Electrons in the dot are assumed to be coupled to a phonon bath. The influence of electron-phonon coupling on tunnelling current, linear and nonline

E. Dalessandro, B. Lanzoni, F. R. Ferraro, F. Vespe

We have used a combination of ACS-HST high-resolution and wide-field SUBARU data in order to study the Blue Straggler Star (BSS) population over the entire extension of the remote Galactic globular cluster NGC 2419. The BSS population presented here is among the largest ever observed in any stellar system, with more than 230 BSS in the brightest portion of t

TAPS Collaboration, M. Nanova

The exclusive reactions $γp \to K^{*0} Σ^+(1189)$ and $γp \to K^{0} π^{0}Σ^+(1189)$, leading to the p 4$π^{0}$ final state, have been measured with a tagged photon beam for incident energies from threshold up to 2.5 GeV. The experiment has been performed at the tagged photon facility of the ELSA accelerator (Bonn). The Crystal Barrel and TAPS detectors were

K. Theis-Broehl, A. Westphalen, H. Zabel, U. Ruecker

A combination of experimental techniques, e.g. vector-MOKE magnetometry, Kerr microscopy and polarized neutron reflectometry, was applied to study the field induced evolution of the magnetization distribution over a periodic pattern of alternating exchange bias stripes. The lateral structure is imprinted into a continuous ferromagnetic/antiferromagnetic exch

B. A. Cumberland, J. C. Travers, S. V. Popov, J. R. Taylor

A 29 W CW supercontinuum spanning from 1.06 to 1.67 um is generated in a short length of PCF with two zero dispersion wavelengths. The continuum has the highest spectral power density, greater than 50 mW/nm up to 1.4 um, reported to date. The use of a short length of PCF enables the continuum to expand beyond the water loss at 1.4 um. The dynamics of the con

G. T. Adamashvili, A. Knorr

The linear and nonlinear surface waves propagating along the interface separating isotropic conventional and uniaxially anisotropic left-handed materials is investigated. The conditions of the existence of surface TM-modes is determined. It is shown that surface waves can be formed when the components of the permittivity and permeability tensors of the uniax

John Fountain, Mark Kambites

Our first main result shows that a graph product of right cancellative monoids is itself right cancellative. If each of the component monoids satisfies the condition that the intersection of two principal left ideals is either principal or empty, then so does the graph product. Our second main result gives a presentation for the inverse hull of such a graph

Md. Nurujjaman, A. N. Sekar Iyengar, Punit Parmananda

Stochastic Resonance (SR) and Coherence Resonance (CR) have been studied experimentally in the discharge plasma close to a homoclinic bifurcation. For the SR phenomena, it is observed that a superimposed subthreshold periodic signal can be recovered via stochastic modulations of the discharge voltage. Furthermore, it is realized that even in the absence of a

Roberto C. Alamino, David Saad

Using methods of statistical physics, we study the average number and kernel size of general sparse random matrices over GF(q), with a given connectivity profile, in the thermodynamical limit of large matrices. We introduce a mapping of $GF(q)$ matrices onto spin systems using the representation of the cyclic group of order q as the q-th complex roots of uni

Jean-Luc Fouquet, Jean-Marie Vanherpe

We extend the notion of $P_4$-sparse graphs previously introduced by {\scshape Hoàng} by considering $\mathcal{F}$-sparse graphs were $\mathcal{F}$ denotes a finite set of graphs on $p$ vertices. Thus we obtain some results on $(P_5,\bar{P_5})$-sparse graphs already known on $(P_5,\bar{P_5})$-free graphs. Finally we completely describe the structure of $(P_5

T. T. Sumi, K. Ogata

The triple differential cross section (TDX) for the 12C(p,2p) proton knockout reaction from the 1p3/2 single-particle state measured at 392 MeV is investigated by nonrelativistic distorted wave impulse approximation (DWIA) with accurate treatment of the kinematics of the colliding two protons and effects of in-medium modification to the matrix elements of th

Ronald W. Butler, Marc S. Paolella

Ratios of quadratic forms in correlated normal variables which introduce noncentrality into the quadratic forms are considered. The denominator is assumed to be positive (with probability 1). Various serial correlation estimates such as least-squares, Yule--Walker and Burg, as well as Durbin--Watson statistics, provide important examples of such ratios. The

Ian Doust, Venta Terauds

On a reflexive Banach space $X$, if an operator $T$ admits a functional calculus for the absolutely continuous functions on its spectrum $σ(T) \subseteq \mathbb{R}$, then this functional calculus can always be extended to include all the functions of bounded variation. This need no longer be true on nonreflexive spaces. In this paper, it is shown that on mos

Jack Liddle, Michael Teper

We study the deconfining transition of SU(N) gauge theories in 2+1 dimensions for N ranging between N=2 and N=8. We confirm that the transition is second order for N<4 and first order for N>4. For the more delicate case of SU(4) all our evidence points to the transition being weakly first order. After extrapolating to the continuum limit, we obtain a deconfi

A. V. Kolobov, A. S. Mishchenko, P. Fons, S. M. Yakubenya

We propose that the driving force of an ultrafast crystalline-to-amorphous transition in phase-change memory alloys are strained bonds existing in the (metastable) crystalline phase. For the prototypical example of GST, we demonstrate that upon breaking of long Ge-Te bond by photoexcitation Ge ion shot from an octahedral crystalline to a tetrahedral amorphou

M. Barnabei, F. Bonetti, M. Silimbani

We define an analogue of signed Eulerian numbers $f_{n,k}$ for involutions of the symmetric group and derive some combinatorial properties of this sequence. In particular, we exhibit both an explicit formula and a recurrence for $f_{n,k}$ arising from the properties of its generating function.

Qing-Rui Dong

The chemical potential of a quantum dot parabolically confining one or two electrons is studied in an axial magnetic field. The number of electrons in the dot is given by combination between the chemical potentials of the dots and leads. The equilibrium-charge diagram of the dot is obtained in the phase space determined by the magnetic field and the lead vol

Hongwen Guo, Hira L. Koul

This paper discusses asymptotic distributions of various estimators of the underlying parameters in some regression models with long memory (LM) Gaussian design and nonparametric heteroscedastic LM moving average errors. In the simple linear regression model, the first-order asymptotic distribution of the least square estimator of the slope parameter is obse

Leif Boysen, Axel Munk

We consider estimation of a step function $f$ from noisy observations of a deconvolution $ϕ*f$, where $ϕ$ is some bounded $L_1$-function. We use a penalized least squares estimator to reconstruct the signal $f$ from the observations, with penalty equal to the number of jumps of the reconstruction. Asymptotically, it is possible to correctly estimate the numb

Hongquan Xu, Ching-Shui Cheng

Chen and Cheng [Ann. Statist. 34 (2006) 546--558] discussed the method of doubling for constructing two-level fractional factorial designs. They showed that for $9N/32\le n\le 5N/16$, all minimum aberration designs with $N$ runs and $n$ factors are projections of the maximal design with $5N/16$ factors which is constructed by repeatedly doubling the $2^{5-1}

J. A. Calzada, S. Kuru, J. Negro, M. A. del Olmo

A class of quantum superintegrable Hamiltonians defined on a two-dimensional hyperboloid is considered together with a set of intertwining operators connecting them. It is shown that such intertwining operators close a su(2,1) Lie algebra and determine the Hamiltonians through the Casimir operators. By means of discrete symmetries a broader set of operators

Guiyun Liang, Gang Zhao

Line ratio of $3d-2p$ transition lines in boron-like spectra of Si X, S XII, Ar XIV and Fe XXII has been investigated. Collisional-radiative model calculations reveal that the line ratio is sensitive to the electron density in ranges of $n_{\rm e}=4.0\times10^7-3.0\times10^{10}$ cm$^{-3}$, $4.0\times10^8-3.0\times10^{11}$ cm$^{-3}$, $3.0\times10^9-4.0\times1

Pedro Tarazona, Umberto Marini Bettolo Marconi

Motivated by recent studies on the dynamics of colloidal solutions in narrow channels, we consider the steady state properties of an assembly of non interacting particles subject to the action of a traveling potential moving at a constant speed while the solvent is modeled by a heat bath at rest in the laboratory frame. Since the description, we propose here

Amit Tribedi, Indrani Bose

We consider a spin ladder model which is known to have matrix product states as exact ground states with spin liquid characteristics. The model has two critical-point transitions at the parameter values u=0 and infinity. We study the variation of entanglement and fidelity measures in the ground states as a function of u and specially look for signatures of q

S. T. Lin, Y. Y. Lin, Y. C. Huang, A. C. Chiang

We report a continuous-wave, singly resonant optical parametric oscillator (SRO) at 3.3 μm by using a MgO:PPLN crystal as the gain medium and a Yb-fiber laser at 1.064 μm as the pump source. At 25-W pump power, the SRO generated 7.4 and 0.2-W powers at 1.57 and 3.3 μm, respectively. The 3.3-μm SRO has a single-longitudinal-mode output with a ~5-MHz linewidth

M. Barnabei, F. Bonetti, M. Silimbani

We introduce an infinite family of lower triangular matrices $Γ^{(s)}$, where $γ_{n,i}^s$ counts the standard Young tableaux on $n$ cells and with at most $s$ columns on a suitable subset of shapes. We show that the entries of these matrices satisfy a three-term row recurrence and we deduce recursive and asymptotic properties for the total number $τ_s(n)$ of

Colin Christopher, Pavao Mardešić

We consider families of Abelian integrals arising from perturbations of planar Hamiltonian systems. The tangential center focus problem asks for the conditions under which these integrals vanish identically. The problem is closely related to the monodromy problem, which asks when the monodromy of a vanishing cycle generates the whole homology of the level cu

Hiroaki Kohyama

We construct the phase diagram of the quark-antiquark and diquark condensates at finite temperature and density in the 2 + 1 dimensional (3D) two flavor massless Gross Neveu (GN) model with the 4-component quarks. In contrast to the case of the 2-component quarks, there appears the coexisting phase of the quark-antiquark and diquark condensates. This is the

X. Fang, A. S. Hedayat

A class of nonlinear models combining a pharmacokinetic compartmental model and a pharmacodynamic Emax model is introduced. The locally D-optimal (LD) design for a four-parameter composed model is found to be a saturated four-point uniform LD design with the two boundary points of the design space in the LD design support. For a five-parameter composed model

Daniel Caro, Nobuo Tsuzuki

We prove the overholonomicity of overconvergent $F$-isocrystals over smooth varieties. This implies that the notions of overholonomicity and devissability in overconvergent $F$-isocrystals are equivalent. Then the overholonomicity is stable under tensor products. So, the overholonomicity gives a $p$-adic cohomology stable under Grothendieck&#39;s cohomologic

O. C. de Jager

In this paper we show that the high energy $γ$-ray flux in the GeV domain from mature pulsar wind nebulae (PWN) scales as the change in rotational kinetic energy $I(Ω_0^2-Ω^2)/2$ since birth, rather than the present day spindown power $IΩ\dotΩ$. This finding holds as long as the lifetime of inverse Compton emitting electrons exceeds the age of the system. Fo

Robert Juhlin, Bernhard Lamel, Francine Meylan

It is shown that a real-valued formal meromorphic function on a formal generic submanifold of finite Kohn-Bloom-Graham type is necessarily constant.

A. L. Chudnovskiy, J. Swiebodzinski, A. Kamenev

Spin polarized current may transfer angular momentum to a ferromagnet, resulting in a spin-torque phenomenon. At the same time the shot noise, associated with the current, leads to a non-equilibrium stochastic force acting on the ferromagnet. We derive stochastic version of Landau-Lifshitz-Gilbert equation for a magnetization of a &#39;&#39;free&#39;&#39; fe

F. Jay Breidt, Jean D. Opsomer

Post-stratification is frequently used to improve the precision of survey estimators when categorical auxiliary information is available from sources outside the survey. In natural resource surveys, such information is often obtained from remote sensing data, classified into categories and displayed as pixel-based maps. These maps may be constructed based on

Rostyslav Voytsitskyy

It is shown that the hyperspace of all nonempty closed subsets $\Cld_{AW}(X)$ of a separable metric space $X$ endowed with the Attouch-Wets topology is homeomorphic to a separable Hilbert space if and only if the completion of $X$ is proper, locally connected and contains no bounded connected component, $X$ is topologically complete and not locally compact a

G. Hétet, B. C. Buchler, O. Glöckl, M. T. L. Hsu

We demonstrate experimentally the delay of squeezed light and entanglement using Electromagnetically Induced Transparency (EIT) in a rubidium vapour cell. We perform quadrature amplitude measurements of the probe field and find no appreciable excess noise from the EIT process. From an input squeezing of 3.1 dB at low sideband frequencies, we observed the sur

Peter Hall, Jiashun Jin

The problem of signal detection using sparse, faint information is closely related to a variety of contemporary statistical problems, including the control of false-discovery rate, and classification using very high-dimensional data. Each problem can be solved by conducting a large number of simultaneous hypothesis tests, the properties of which are readily

G. M. Saxena

We define quantum phase in terms of inverses of annihilation and creation operators. We show that like Susskind - Glogower phase operators, the measured phase operators and the unitary phase operators can be defined in terms of the inverse operators. However, for the unitary phase operator the Hilbert space includes the negative energy states. The quantum ph

Yoann Pigné, Antoine Dutot, Frédéric Guinand, Damien Olivier

The notion of complex systems is common to many domains, from Biology to Economy, Computer Science, Physics, etc. Often, these systems are made of sets of entities moving in an evolving environment. One of their major characteristics is the emergence of some global properties stemmed from local interactions between the entities themselves and between the ent

Frédéric Guinand, Yoann Pigné

Multiple sequence alignment is a key process in today&#39;s biology, and finding a relevant alignment of several sequences is much more challenging than just optimizing some improbable evaluation functions. Our approach for addressing multiple sequence alignment focuses on the building of structures in a new graph model: the factor graph model. This model re

Agnes Huynh, Bernard Perrin, N. D. Lanzillotti Kimura, Bernard Jusserand

We demonstrate semiconductor superlattices or nanocavities as narrow band acoustic transducers in the sub-terahertz range. Using picosecond ultrasonics experiments in the transmission geometry with pump and probe incident on opposite sides of the thick substrate, phonon generation and detection processes are fully decoupled. Generating with the semiconductor

S. Horiuchi, T. Shirakawa, Y. Ohta

We consider electronic properties of hollandite vanadate K$_2$V$_8$O$_{16}$, a one-dimensional zigzag-chain system of $t_{2g}$ orbitals in a mixed valent state. We first calculate the Madelung energy and obtain the relative stability of several charge-ordering patterns to determine the most stable one that is consistent with the observed superlattice structu

Maddala Sundari

We extend a result of Hulanicki- Ricci to all H-type groups.

Agnieszka Janiuk, Daniel Proga, Ryuichi Kurosawa

We report on the fourth phase of our study of slightly rotating accretion flows onto black holes. The main new element of this study is that we used fully three dimensional (3-D) numerical simulations. We consider hydrodynamics of inviscid accretion flows. We assume a spherically symmetric density distribution at the outer boundary, but brake the flow symmet

Sylvain Foret, Susan R. Wilson, Conrad J. Burden

This study focuses on an alignment-free sequence comparison method: the number of words of length k shared between two sequences, also known as the D_2 statistic. The advantages of the use of this statistic over alignment-based methods are firstly that it does not assume that homologous segments are contiguous, and secondly that the algorithm is computationa

H. Tamaki, Y. Ohashi, K. Miyake

We investigate the superfluid phase transition in a gas of Fermi atoms loaded on a three-dimensional optical lattice. When the lattice potential is strong, this system can be well described by an attractive Hubbard model. In this model, we calculate the superfluid phase transition temperature Tc, including both superfluid and (spin and charge) density fluctu

Atsushi Nakayashiki

An expression of the multivariate sigma function associated with a (n,s)-curve is given in terms of algebraic integrals. As a corollary the first term of the series expansion around the origin of the sigma function is directly proved to be the Schur function determined from the gap sequence at infinity.

Demosthenes Kazanas

We present a brief review of Cosmological Inflation from the personal perspective of the author who almost 30 years ago proposed a way of resolving the problem of Cosmological Horizon by employing certain notions and developments from the field of High Energy Physics. Along with a brief introduction of the Horizon and Flatness problems of standard cosmology,

Ken-ichi Sugiyama

We will show a theorem of a type of Cheeger and Muller for a noncompact complete hyperbolic threefold of finite vulume. As an application we will compute a special value of Ruelle L-function at the origin for a unitary local system which is cuspidal.

S. D. Kaushik, V. Braccini, S. Patnaik

The dissipative mechanism at low current density is compared in three different classes of superconductors. This is achieved by measurement of resistance as a function of temperature and magnetic field in clean polycrystalline samples of NbSe2, MgB2 and Bi2Sr2Ca2Cu3O10 superconductors. Thermally activated flux flow behavior is clearly identified in bulk MgB2

C. Sivaram

The supermassive short period black hole binary OJ287 is discussed as a new precision testing ground for general relativity and alternate gravity theories. Like in the case of binary pulsars, the relativistic gravity effects are considerably larger than in the solar system. For instance the observed orbital precession is forty degrees per period. The gravita

B. Desplanques, C. H. Hyun, S. Ando, C. -P. Liu

Two-pion exchange parity-violating nucleon-nucleon interactions from recent effective field theories and earlier fully covariant approaches are investigated. The potentials are compared with the idea to obtain better insight on the role of low-energy constants appearing in the effective field theory approach and the convergence of this one in terms of a pert

Er-Jun Kan, Xiaojun Wu, Zhenyu Li, X. C. Zeng

We report a first-principles electronic-structure calculation on C and BN hybrid zigzag nanoribbons. We find that half-metallicity can arise in the hybrid nanoribbons even though stand-alone C or BN nanoribbon possesses a finite band gap. This unexpected half-metallicity in the hybrid nanos-tructures stems from a competition between the charge and spin polar

Ari Stern, Yiying Tong, Mathieu Desbrun, Jerrold E. Marsden

In recent years, two important techniques for geometric numerical discretization have been developed. In computational electromagnetics, spatial discretization has been improved by the use of mixed finite elements and discrete differential forms. Simultaneously, the dynamical systems and mechanics communities have developed structure-preserving time integrat

Iosif Pinelis

For any continuous zero-mean random variable (r.v.) X, a reciprocating function r is constructed, based only on the distribution of X, such that the conditional distribution of X given the (at-most-)two-point set {X,r(X)} is the zero-mean distribution on this set; in fact, a more general construction without the continuity assumption is given in this paper,

Yan Zhao, Christos Argyropoulos, Yang Hao

This paper proposes a radial dependent dispersive finite-difference time-domain method for the modelling of electromagnetic cloaking structures. The permittivity and permeability of the cloak are mapped to the Drude dispersion model and taken into account in dispersive FDTD simulations. Numerical simulations demonstrate that under ideal conditions, objects p

Manfred Herbst, Kentaro Hori, David Page

We study B-type D-branes in linear sigma models with Abelian gauge groups. The most important finding is the grade restriction rule. It classifies representations of the gauge group on the Chan-Paton factor, which can be used to define a family of D-branes over a region of the Kähler moduli space that connects special points of different character. As an app

Milan Batista

A method for solving cyclic block three-diagonal systems of equations is generalized for solving a block cyclic penta-diagonal system of equations. Introducing a special form of two new variables the original system is split into three block pentagonal systems, which can be solved by the known methods. As such method belongs to class of direct methods withou

Martin R. Bridson, Karen Vogtmann

For n at least 3, let SAut(F_n) denote the unique subgroup of index two in the automorphism group of a free group. The standard linear action of SL(n,Z) on R^n induces non-trivial actions of SAut(F_n) on R^n and on S^{n-1}. We prove that SAut(F_n) admits no non-trivial actions by homeomorphisms on acyclic manifolds or spheres of smaller dimension. Indeed, SA

A. Psaker, W. Melnitchouk, M. E. Christy, C. Keppel

We employ a novel new approach to study local quark-hadron duality using &#34;truncated&#34; moments, or integrals of structure functions over restricted regions of x, to determine the degree to which individual resonance regions are dominated by leading twist. Because truncated moments obey the same Q^2 evolution equations as the leading twist parton distri

Jon Urrestilla, Pia Mukherjee, Andrew R. Liddle, Neil Bevis

While observations indicate that the predominant source of cosmic inhomogeneities are adiabatic perturbations, there are a variety of candidates to provide auxiliary trace effects, including inflation-generated primordial tensors and cosmic defects which both produce B-mode cosmic microwave background (CMB) polarization. We investigate whether future experim

Nils Bruin, Michael Stoll

We describe an algorithm that determines a set of unramified covers of a given hyperelliptic curve, with the property that any rational point will lift to one of the covers. In particular, if the algorithm returns an empty set, then the hyperelliptic curve has no rational points. This provides a relatively efficiently tested criterion for solvability of hype

Michele Maltoni, Walter Winter

We discuss the interplay of neutrino oscillation and decay properties at neutrino telescopes. Motivated by recent unparticle scenarios, which open the possibility of new neutrino decay modes over astrophysical distances, we perform a complete classification of possible decay schemes, and we illustrate how different scenarios can be identified. Moreover, we s

M. Ruggenthaler, S. V. Popruzhenko, D. Bauer

Recolliding electrons are responsible for many of the interesting phenomena observed in the interaction of strong laser fields with atoms and molecules. We show that in multielectron targets such as C60 a new important recollision pathway opens up: the returning electron may excite collective modes even if the laser frequency is far off-resonant. We formulat

M. J. Ireland, A. L. Kraus

CoKu Tau/4 has been labeled as one of the very few known transition disk objects: disks around young stars that have their inner disks cleared of dust, arguably due to planetary formation. We report aperture-masking interferometry and adaptive optics imaging observations showing that CoKu Tau/4 is in fact a near-equal binary star of projected separation $\si

Jose A. Ramirez, Brian Rider

We show that the limiting minimal eigenvalue distributions for a natural generalization of Gaussian sample-covariance structures (the &#34;beta ensembles&#34;) are described by the spectrum of a random diffusion generator. By a Riccati transformation, we obtain a second diffusion description of the limiting eigenvalues in terms of hitting laws. This picture

E. Arganda, M. J. Herrero, J. Portoles

In this work we study the Lepton Flavour Violating semileptonic $τ$ decays: 1) $τ\to μPP$ with $PP= π^+π^-, π^0π^0, K^+K^-, K^0 {\bar K}^0$; 2) $τ\to μP$ with $P=π^0, η, η&#39;$ and 3) $τ\to μV$ with $V = ρ^0, ϕ$. We work within the context of two constrained MSSM scenarios: the CMSSM and NUHM. A full one-(SUSY)loop computation is presented and the importanc

Jose L. F. Barbon, Carlos A. Fuertes

We study the short-distance structure of geometric entanglement entropy in certain theories with a built-in scale of nonlocality. In particular we examine the cases of Little String Theory and Noncommutative Yang-Mills theory, using their AdS/CFT descriptions. We compute the entanglement entropy via the holographic ansatz of Ryu and Takayanagi to conclude th

Camille Laurent-Gengoux, Mathieu Stienon, Ping Xu

We prove that a holomorphic Lie algebroid is integrable if, and only if, its underlying real Lie algebroid is integrable. Thus the integrability criteria of Crainic-Fernandes do also apply in the holomorphic context without any modification. As a consequence we give another proof of the following theorem: a holomorphic Poisson manifold is integrable if, and