January 2010 arXiv papers — page 15

Martin Avendano, Ashraf Ibrahim, J. Maurice Rojas, Korben Rusek

We show that deciding whether a sparse univariate polynomial has a p-adic rational root can be done in NP for most inputs. We also prove a polynomial-time upper bound for trinomials with suitably generic p-adic Newton polygon. We thus improve the best previous complexity upper bound of EXPTIME. We also prove an unconditional complexity lower bound of NP-hard

Vincent Aravantinos, Ricardo Caferra, Nicolas Peltier

Many problems can be specified by patterns of propositional formulae depending on a parameter, e.g. the specification of a circuit usually depends on the number of bits of its input. We define a logic whose formulae, called "iterated schemata", allow to express such patterns. Schemata extend propositional logic with indexed propositions, e.g. P_i, P_

M. Tahir, A. MacKinnon

We present a theoretical study of time-dependent quantum transport in a resonant tunnel junction coupled to a nanomechanical oscillator within the non-equilibrium Green's function technique. An arbitrary voltage is applied to the tunnel junction and electrons in the leads are considered to be at zero temperature. The transient and the steady state behavi

Bela Bollobas, Vladimir Nikiforov

In this note, extending some results of Erdos, Frankl, Rodl, Alexeev, Bollobas and Thomason we determine asymptotically the number of graphs which do not contain certain large subgraphs. In particular, if H_1,...,H_n,... are graphs with chromatic numbers r_1,...,r_n,... and order o(log n), we dermine asymptotically the number of graphs of order n not contain

Manfred Bohn, Dieter W. Heermann

Chromatin looping is a major epigenetic regulatory mechanism in higher eukaryotes. Besides its role in transcriptional regulation, chromatin loops have been proposed to play a pivotal role in the segregation of entire chromosomes. The detailed topological and entropic forces between loops still remain elusive. Here, we quantitatively determine the potential

D. W. Higinbotham, V. Sulkosky

Recent cross section (e,e'pN) short-range correlation experiments have clearly shown the strong dominance of tensor correlations for (e,e'p) missing momenta greater than the Fermi momentum; while recent D(e,e'p)n and 4He(e,e'p)t asymmetry experiments at low missing momentum have shown small changes from the free nucleon form factor. By doing

Luc Haine, Didier Vanderstichelen

We consider the 2-dimensional Toda lattice tau functions $τ_n(t,s;η,θ)$ deforming the probabilities $τ_n(η,θ)$ that a randomly chosen matrix from the unitary group U(n), for the Haar measure, has no eigenvalues within an arc $(η,θ)$ of the unit circle. We show that these tau functions satisfy a centerless Virasoro algebra of constraints, with a boundary part

Abdenacer Makhlouf

The aim of this paper is to give a survey of nonassociative Hom-algebra and Hom-superalgebra structures. The main feature of these algebras is that the identities defining the structures are twisted by homomorphisms. We discuss Hom-associative algebras, Hom-Flexible algebras, Hom-Lie algebras, $G$-hom-associative algebras, Hom-Poisson algebras, Hom-alternati

Jan Christian Rohde

We study the generic Hodge groups $\Hg(\sX)$ of local universal deformations $\sX$ of Calabi-Yau 3-manifolds with onedimensional complex moduli, give a complete list of all possible choices for $\Hg(\sX)_{\R}$ and determine the latter real groups for known examples.

Pawel Sobkowicz

We provide a technical report on a computer simulation of general effectiveness of a hierarchical organization depending on two main aspects: effects of promotion to managerial levels and efforts to self-promote of individual employees, reducing their actual productivity. The combination of judgment by appearance in the promotion to higher levels of hierarch

M. Reshetnyak

It is shown, that the saturated $α$-effect taken from the nonlinear dynamo equations for the thin disk can still produce exponentially growing magnetic field in the case, when this field does not feed back on the $α$. For negative dynamo number (stationary regime) stability is defined by the structure of the spectra of the linear problem for the positive dyn

Azam Izadi, Ali Shojai

We consider f(R) modified gravity theories for describing varying speed of light in a spatially flat FRW model, and find some exact solutions. Also we examine the dynamics of this model by dynamical system method assuming a LambdaCDM background and we find some exact solutions by considering the character of critical points of the theory in both formalisms.

H. Bartko

We summarize our latest observations of the nuclear star cluster in the central parsec of the Galaxy with the adaptive optics assisted, integral field spectrograph SINFONI on the ESO/VLT, which result in a total sample of 177 bona fide early-type stars. We find that most of these Wolf Rayet (WR), O- and B- stars reside in two strongly warped eccentric (<e> =

James King, David Kirkpatrick

We provide an O(log log OPT)-approximation algorithm for the problem of guarding a simple polygon with guards on the perimeter. We first design a polynomial-time algorithm for building epsilon-nets of size O(1/epsilon log log 1/epsilon) for the instances of Hitting Set associated with our guarding problem. We then apply the technique of Bronnimann and Goodri

Hiroshi Kamata, Takeshi Ota, Koji Muraki, Toshimasa Fujisawa

We investigate the group velocity of edge magnetoplasmons (EMPs) in the quantum Hall regime by means of time-of-flight measurement. The EMPs are injected from an Ohmic contact by applying a voltage pulse, and detected at a quantum point contact by applying another voltage pulse to its gate. We find that the group velocity of the EMPs traveling along the edge

Si Lin, Xiong Ge, Leng Gangsong

In this paper, we give a description of the John contact points of a regular simplex. We prove that the John ellipsoid of any simplex is ball if and only if this simplex is regular and that the John ellipsoid of a regular simplex is its inscribed ball.

Luling Jin, Yueping Niu, Shangqing Gong

We report the phase control of spatial interference of resonance fluorescence from two duplicated two-level atoms, driving by two orthogonally polarized fields. In this closed-loop system, the relative phase is of crucial importance to the recovery of the interference patten in the fluorescence light even with strong driving.In order to improve the experimen

Vesselin Petkov

For several decades there has been no breakthrough in fundamental physics as revolutionary as relativity and quantum physics despite the amazing advancement of applied physics and technology. By discussing several examples of what physics could have achieved by now, but failed, I will argue that the present state of fundamental physics is not caused by the l

Pascal Berthome, Raul Cordovil, David Forge, Veronique Ventos

A gain graph is a graph whose edges are labelled invertibly by &#34;gains&#34; from a group. &#34;Switching&#34; is a transformation of gain graphs that generalizes conjugation in a group. A &#34;weak chromatic function&#34; of gain graphs with gains in a fixed group satisfies three laws: deletion-contraction for links with neutral gain, invariance under swi

H. B. Thacker

Lattice Monte Carlo studies in SU(3) gauge theory have shown that the topological charge distribution in the vacuum is dominated by thin coherent membranes of codimension one arranged in a layered, alternating-sign sandwich. A similar lamination of topological charge occurs in the 2D $CP^{N-1}$ model. In holographic QCD, the observed topological charge sheet

R. Jerry, L. Winslow, L. Bugel, J. M. Conrad

Tetraphenyl-butadiene (TPB) is a widely used fluorescent wavelength-shifter. A common application is in liquid-argon-based particle detectors, where scintillation light is produced in the UV at 128 nm. In liquid argon experiments, TPB is often employed to shift the scintillation light to the visible range in order to allow detection via standard photomultipl

B. D. Acharya, K. A. Germina, Kumar Abhishek, S. B. Rao

In a digraph $D = (X, \mathcal{U})$, not necessarily finite, an arc $(x, y) \in \mathcal{U}$ is reachable from a vertex $u$ if there exists a directed walk $W$ that originates from $u$ and contains $(x, y)$. A subset $S \subseteq X$ is an arc-reaching set of $D$ if for every arc $(x, y)$ there exists a diwalk $W$ originating at a vertex $u \in S$ and contain

N. A. Sinitsyn, I. Nemenman

We generalize the concept of the geometric phase in stochastic kinetics to a noncyclic evolution. Its application is demonstrated on kinetics of the Michaelis-Menten reaction. It is shown that the nonperiodic geometric phase is responsible for the correction to the Michaelis-Menten law when parameters, such as a substrate concentration, are changing with tim

Alexander Ivanchin

It has been shown that to calculate the parameters of the electrostatic field of the ion crystal lattice it sufficient to take into account ions located at a distance of 1-2 lattice spacings. More distant ions make insignificant contribution. As a result, the electrostatic energy of the ion lattice in the alkaline halide crystal produced by both positive and

Yi-Chun Xu, Fang-Min Dong, Yong Liu, Ren-Bin Xiao

This paper discusses the problem of placing weighted items in a circular container in two-dimensional space. This problem is of great practical significance in various mechanical engineering domains, such as the design of communication satellites. Two constructive heuristics are proposed, one for packing circular items and the other for packing rectangular i

Mikael Passare, Boris Shapiro, J. Maurice Rojas

In their classic 1914 paper, Polya and Schur introduced and characterized two types of linear operators acting diagonally on the monomial basis of R[x], sending real-rooted polynomials (resp. polynomials with all nonzero roots of the same sign) to real-rooted polynomials. Motivated by fundamental properties of amoebae and discriminants discovered by Gelfand,

A. L. Kataev, V. T. Kim

Perturbative relations between pole and running heavy quark masses, defined in the Minkowski regions, are considered. Special attention is paid to the appearance of the kinematic $π^2$-effects, which exist in the coefficients of these series. The estimates of order $O(α_s^4)$ QCD corrections are presented.

Valentina Cammarota, Aimé Lachal

Consider the high-order heat-type equation $\partial u/\partial t=\pm \partial^N u/\partial x^N$ for an integer $N>2$ and introduce the related Markov pseudo-process $(X(t))_{t\ge 0}$. In this paper, we study the sojourn time $T(t)$ in the interval $[0,+\infty)$ up to a fixed time $t$ for this pseudo-process. We provide explicit expressions for the joint dis

George T. Kottanattu, Jorma Louko

We construct topological geon quotients of two families of Einstein-Yang-Mills black holes. For Kuenzle&#39;s static, spherically symmetric SU(n) black holes with n>2, a geon quotient exists but generically requires promoting charge conjugation into a gauge symmetry. For Kleihaus and Kunz&#39;s static, axially symmetric SU(2) black holes a geon quotient exis

Wei Li, Ruibao Tao

On the basis of tight-binding lattice model, the edge states of monolayer and bilayer graphene nanoribbons (GNRs) with different edge terminations are studied. The effects of edge-hopping modulation, spin-orbital coupling (SOC), and bias voltage on bilayer GNRs are discussed. We observe the following: (i) Some new extra edge states can be created by edge-hop

Hanno Sahlmann

In this article we review the foundations and the present status of loop quantum gravity. It is short and relatively non-technical, the emphasis is on the ideas, and the flavor of the techniques. In particular, we describe the kinematical quantization and the implementation of the Hamilton constraint, as well as the quantum theory of black hole horizons, sem

Ignacio Cortese, J Antonio García

Starting from a standard noncommutative gauge theory and using the Seiberg-Witten map we propose a new version of a noncommutative gravity. We use consistent deformation theory starting from a free gauge action and gauging a killing symmetry of the background metric to construct a deformation of the gauge theory that we can relate with gravity. The result of

Milan S. Derpich, Jan Østergaard

We improve the existing achievable rate regions for causal and for zero-delay source coding of stationary Gaussian sources under an average mean squared error (MSE) distortion measure. To begin with, we find a closed-form expression for the information-theoretic causal rate-distortion function (RDF) under such distortion measure, denoted by $R_{c}^{it}(D)$,

Yu Seon Jeong, M. H. Reno

We evaluate the neutrino nucleon charged current cross section at next-to-leading order in quantum chromodynamic corrections in the variable flavor number scheme and the fixed flavor number scheme, taking into account quark masses. The number scheme dependence is largest at the highest energies considered here, $10^{12}$ GeV, where the cross sections differ

Benjamin M. Fregoso, Eduardo Fradkin

We study the magnetic structure of the ground state of an itinerant Fermi system of spin-\nicefrac{1}{2} particles with magnetic dipole-dipole interactions. We show that, quite generally, the spin state of particles depend on its momentum, i.e., spin and orbital degrees of freedom are entangled and taken separately are not ``good&#39;&#39; quantum numbers. S

P. B. Gossiaux, J. Aichelin, T. Gousset, V. Guiho

We extend our recently advanced model on collisional energy loss of heavy quarks in a quark gluon plasma (QGP) by including radiative energy loss. We discuss the approach and present first preliminary results. We show that present data on nuclear modification factor of non photonic single electrons hardly permit to distinguish between those 2 energy loss mec

Takayuki Hibi, Akihiro Higashitani, Hidefumi Ohsugi

Given arbitrary integers $k$ and $d$ with $0 \leq 2k \leq d$, we construct a Gorenstein Fano polytope $\Pc \subset \RR^d$ of dimension $d$ such that (i) its Ehrhart polynomial $i(\Pc, n)$ possesses $d$ distinct roots; (ii) $i(\Pc, n)$ possesses exactly $2k$ imaginary roots; (iii) $i(\Pc, n)$ possesses exactly $d - 2k$ real roots; (iv) the real part of each o

D. Sornette, V. Pisarenko

In a Forum published in EOS Transactions AGU (2009) entitled &#34;Lies, damned lies and statistics (in Geology)&#34;, Vermeesch (2009) claims that &#34;statistical significant is not the same as geological significant&#34;, in other words, statistical tests may be misleading. In complete contradiction, we affirm that statistical tests are always informative.

O. G. Rodriguez-Herrera, D. Lara, K. Y. Bliokh, E. A. Ostrovskaya

We show, both theoretically and experimentally, that high-numerical-aperture (NA) optical microscopy is accompanied by strong spin-orbit interaction of light, which translates fine infomation about the specimen to the polarization degrees of freedom of light. An 80nm gold nano-particle scattering the light in the focus of a high-NA objective generates angula

P. S. Bisht, Pushpa, O. P. S. Negi

Starting with the generalized electromagnetic field equations of dyons, we have discussed the theory of magnetohydrodynamics (MHD) of plasma for particles carrying simultaneously the electric and magnetic charges (namely dyons). It is shown that the resultant system supports the electromagnetic duality of dyons. Consequently the frequency of dyonic plasma ha

Sagar Shenvi, Bikash Kumar Dey

We consider a directed acyclic network with three sources and three terminals such that each source independently generates one symbol from a given field $F$ and each terminal wants to receive the sum (over $F$) of the source symbols. Each link in the network is considered to be error-free and delay-free and can carry one symbol from the field in each use. W

Vassil S. Dimitrov, Everett W. Howe

A double-base representation of an integer n is an expression n = n_1 + ... + n_r, where the n_i are (positive or negative) integers that are divisible by no primes other than 2 or 3; the length of the representation is the number r of terms. It is known that there is a constant a > 0 such that every integer n has a double-base representation of length at mo

Emmanuel Clouet

Nucleation is the onset of a first-order phase transition by which a metastable phase transforms into a more stable one. Such a phase transition occurs when an initial system initially in equilibrium is destabilized by the change of an external parameter like the temperature or the pressure. If the perturbation is small enough, the system does not become uns

Xavier Allamigeon, Stephane Gaubert, Eric Goubault

We develop a tropical analogue of the classical double description method allowing one to compute an internal representation (in terms of vertices) of a polyhedron defined externally (by inequalities). The heart of the tropical algorithm is a characterization of the extreme points of a polyhedron in terms of a system of constraints which define it. We show t

Ben Lund, Justin W Smith

We present a new implementation of the Floyd-Warshall All-Pairs Shortest Paths algorithm on CUDA. Our algorithm runs approximately 5 times faster than the previously best reported algorithm. In order to achieve this speedup, we applied a new technique to reduce usage of on-chip shared memory and allow the CUDA scheduler to more effectively hide instruction l

Chris Wendl

We use contact fiber sums of open book decompositions to define an infinite hierarchy of filling obstructions for contact 3-manifolds, called planar k-torsion for nonnegative integers k, all of which cause the contact invariant in Embedded Contact Homology to vanish. Planar 0-torsion is equivalent to overtwistedness, while every contact manifold with Giroux

Chevrot Nicolas

Let $S$ be the shift operator on the Hardy space $H^2$ and let $S^*$ be its adjoint. A closed subspace $\FF$ of $H^2$ is said to be nearly $S^*$-invariant if every element $f\in\FF$ with $f(0)=0$ satisfies $S^*f\in\FF$. In particular, the kernels of Toeplitz operators are nearly $S^*$-invariant subspaces. Hitt gave the description of these subspaces. They ar

K. N. Gourgouliatos, N. Vlahakis

We study semi-analytical time-dependent solutions of the relativistic magnetohydrodynamic (MHD) equations for the fields and the fluid emerging from a spherical source. We assume uniform expansion of the field and the fluid and a polytropic relation between the density and the pressure of the fluid. The expansion velocity is small near the base but approache

Abel Rodriguez, Alex Lenkoski, Adrian Dobra

Standard Gaussian graphical models (GGMs) implicitly assume that the conditional independence among variables is common to all observations in the sample. However, in practice, observations are usually collected form heterogeneous populations where such assumption is not satisfied, leading in turn to nonlinear relationships among variables. To tackle these p

Zywomir Dinew

We study the set where the so-called Bergman representative coordinates (or Bergman functions) form an immersion. We provide an estimate of the size of a maximal geodesic ball with respect to the Bergman metric, contained in this set. By concrete examples we show that these estimates are the best possible.

A. V. Boriskin, G. Godi, R. Sauleau, A. I. Nosich

We assess the accuracy and relevance of the numerical algorithms based on the principles of Geometrical Optics (GO) and Physical Optics (PO) in the analysis of reduced-size homogeneous dielectric lenses prone to behave as open resonators. As a benchmark solution, we use the Muller boundary integral equations discretized with trigonometric Galerkin scheme tha

Alexis Tchoudjem

For a projective variety $X$ and a line bundle $L$ over $X$, one considers the $L-$twisted global differential operator algebra $\call{D}_L(X)$ which naturally operates on the space of global sections $H^0(X,L)$. In the case where $X$ is the wonderful compactification of the group $\mathrm{PGL}_3$, one proves that the space $H^0(X,L)$ is an irreducible repre

Shigeki Akiyama, Jun Luo, Ryotaro Okazaki, Wolfgang Steiner

In 1994, Martin Gardner stated a set of questions concerning the dissection of a square or an equilateral triangle in three similar parts. Meanwhile, Gardner&#39;s questions have been generalized and some of them are already solved. In the present paper, we solve more of his questions and treat them in a much more general context. Let $D\subset \mathbb{R}^d$

Haïja Moustafa

In this paper, we study the K0-group of the C?-algebra associated to a pinwheel tiling. We prove that it is given by the sum of Z + Z^6 with a cohomological group. The C?-algebra is endowed with a trace that induces a linear map on its K0-group. We then compute explicitly the image, under this map, of the summand Z+Z^6, showing that the image of Z is zero an

P. Venkateswari, Dr. T. Purusothaman

This is an Internet era. Most of the organizations try to establish their development centers and branch offices across the World. Employees working from their homes are also becoming very popular and organizations benefit financially by utilizing less office space, and reducing total expenses incurred by having office workers on site. To meet such requireme

Dong-Hyun Kim, Woo-Ram Jung, Chan-Hyun Youn

As science technology grows, medical application is becoming more complex to solve the physiological problems within expected time. Workflow management systems (WMS) in Grid computing are promising solution to solve the sophisticated problem such as genomic analysis, drug discovery, disease identification, etc. Although existing WMS can provide basic managem

R. Nallusamy, K. Duraiswamy, R. Dhanalaksmi, P. Parthiban

This paper deals with generating of an optimized route for multiple Vehicle routing Problems (mVRP). We used a methodology of clustering the given cities depending upon the number of vehicles and each cluster is allotted to a vehicle. k- Means clustering algorithm has been used for easy clustering of the cities. In this way the mVRP has been converted into V

Orfeu Bertolami

The limitations of current technology do not allow one to foresee the expansion of the humankind beyond our planet for at least a few decades. Furthermore, the laws of physics, as for as they are known, preclude any form of traveling beyond the speed of light, as well as any viable and stable space-time shortcuts (wormholes, warp-drives, etc) that would faci

S. S. Riaz Ahamed

Software testing is a critical element of software quality assurance and represents the ultimate review of specification, design and coding. Software testing is the process of testing the functionality and correctness of software by running it. Software testing is usually performed for one of two reasons: defect detection, and reliability estimation. The pro

S. S. Riaz Ahamed

The UML allows us to specify models in a precise, complete and unambiguous manner. In particular, the UML addresses the specification of all important decisions regarding analysis, design and implementation. Although UML is not a visual programming language, its models can be directly connected to a vast variety of programming languages. This enables a dual

S. S. Riaz Ahamed, D. Mahesh

Broadband communications consists of the technologies and equipment required to deliver packet-based digital voice, video, and data services to end users. Broadband affords end users high-speed, always-on access to the Internet while affording service providers the ability to offer value-added services to increase revenues. Due to the growth of the Internet,

A. Srinivasan, K. Srinivasa Rao, K. Kannan, D. Narasimhan

Speech signals of the letter &#39;zha&#39; in Tamil language of 3 males and 3 females were coded using an improved version of Linear Predictive Coding (LPC). The sampling frequency was at 16 kHz and the bit rate was at 15450 bits per second, where the original bit rate was at 128000 bits per second with the help of wave surfer audio tool. The output LPC ceps

H. B. Kekre, Tanuja K. Sarode, Saylee M. Gharge

Segmenting a MRI images into homogeneous texture regions representing disparate tissue types is often a useful preprocessing step in the computer-assisted detection of breast cancer. That is why we proposed new algorithm to detect cancer in mammogram breast cancer images. In this paper we proposed segmentation using vector quantization technique. Here we use

Felix Fontein, Michael J. Jacobson

We present an algorithm that unconditionally computes a representation of the unit group of a number field of discriminant $Δ_K$, given a full-rank subgroup as input, in asymptotically fewer bit operations than the baby-step giant-step algorithm. If the input is assumed to represent the full unit group, for example, under the assumption of the Generalized Ri

Ravi. J, K. B. Raja, Venugopal. K. R

The popular Biometric used to authenticate a person is Fingerprint which is unique and permanent throughout a person&#39;s life. A minutia matching is widely used for fingerprint recognition and can be classified as ridge ending and ridge bifurcation. In this paper we projected Fingerprint Recognition using Minutia Score Matching method (FRMSM). For Fingerpr

S. S. Riaz Ahamed

The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis -- freely available to all. GPS provides specially coded satellite signals that can be processed in a GPS receiver, enabling the receiver to compute position, ve

S. S. Riaz Ahamed

Local multipoint distribution system (LMDS) uses cellular-like network architecture of microwave radios placed at the client&#39;s location and at the company&#39;s base station to deliver fixed services, mainly telephony, video and Internet access. The use of time-division multiple access (TDMA) and FDMA (frequency DMA) technology allows multiple customers

A. Afaq, Iftikhar Ahmad

The total photodetachment cross section of a linear triatomic negative ion using plane polarized laser light parallel to the axis of the molecular ion is derived. The cross section shows strong oscillations in contrast to the recently reported case, where the laser polarization was perpendicular to the axis of the triatomic molecular ion (Appl. Phys. Lett. 9

Radhika Rangarajan, Michael Goggin, Paul Kwiat

Optical quantum information processing needs ultra-bright sources of entangled photons, especially from synchronizable femtosecond lasers and low-cost cw-diode lasers. Decoherence due to timing information and spatial mode-dependent phase has traditionally limited the brightness of such sources. We report on a variety of methods to optimize type-I polarizati

S. P. Avdeyev, V. A. Karnaukhov, H. Oeschler, V. V. Kirakosyan

The relative velocity correlation function of pairs of intermediate mass fragments has been studied for d+Au collitions at 4.4 GeV. Experimental correlation functions are compared to that obtained by multibody Coulomb trajectory calculations under the assumption of various decay timees of the fragmenting system. The combined approach with the empirically mod

Christian Bracco, Jean-Pierre Provost

We highlight four points which have been ignored or underestimated before and which allow a better understanding of &#34;Sur la dynamique de l&#39;electron&#34;: (i) the use by Poincare of active Lorentz transformations (boosts); (ii) the necessity, required by mechanics, of a group condition l=1 eliminating dilations; (iii) the key role of the action (elect

C. T. J. Dodson

This study elaborates some examples of a simple evolutionary stochastic rate process where the population rate of change depends on the distribution of properties--so different cohorts change at different rates. We investigate the effect on the evolution arising from parametrized perturbations of uniformity for the initial inhomogeneity. The information geom

W. Ishibashi, T. J. -L. Courvoisier

X-ray spectra of active galactic nuclei (AGN) are usually described as power law spectra, characterized by the spectral slope $α$ or photon index $Γ$. Here we discuss the X-ray spectral properties within the framework of clumpy accretion flows, and estimate the power law slope as a function of the source parameters. We expect harder spectra in massive object

Jae-Hyouk Lee

In this article, we study the divisor classes of del Pezzo surfaces, which are written as the sum of distinct lines with fixed intersection according to the inscribed simplexes and crosspolytopes in Gosset polytopes. We introduce the k-Steiner system and cornered simplexes, and characterize the configurations of inscribed m(<4)-simplexes with them. Higher di

S. Capozziello, M. De Laurentis, D. Vernieri

The gravitational phase shift of neutrino oscillation can be discussed in the framework of f(R)-gravity. We show that the shift of quantum mechanical phase can depend on the given f(R)-theory that we choose. This fact is general and could constitute a fundamental test to discriminate among the various alternative relativistic theories of gravity. Estimations

Massimo Giovannini

The tensor contribution to the $V$-mode polarization induced by a magnetized plasma at last scattering vanishes exactly. Conversely a polarized background of relic gravitons cannot generate a $V$-mode polarization. The reported results suggest that, in the magnetized $Λ$CDM paradigm, the dominant source of circular dichroism stems from the large-scale fluctu

Bernard Helffer, Johannes Sjoestrand

The purpose of this note is to revisit the proof of the Gearhardt-Prüss-Hwang-Greiner theorem for a semigroup S(t), following the general idea of the proofs that we have seen in the literature and to get an explicit estimate on the norm of S(t) in terms of bounds on the resolvent of the generator.

K. G. Hare, S. Laishram, T. Stoll

Let $s_q(n)$ denote the sum of the digits in the $q$-ary expansion of an integer $n$. In 2005, Melfi examined the structure of $n$ such that $s_2(n) = s_2(n^2)$. We extend this study to the more general case of generic $q$ and polynomials $p(n)$, and obtain, in particular, a refinement of Melfi&#39;s result. We also give a more detailed analysis of the speci

K. G. Hare, S. Laishram, T. Stoll

Let $s_q(n)$ denote the sum of the digits in the $q$-ary expansion of an integer $n$. In 1978, Stolarsky showed that $$ \liminf_{n\to\infty} \frac{s_2(n^2)}{s_2(n)} = 0. $$ He conjectured that, as for $n^2$, this limit infimum should be 0 for higher powers of $n$. We prove and generalize this conjecture showing that for any polynomial $p(x)=a_h x^h+a_{h-1} x

Peter Mani-Levitska

After G. Perelman&#39;s solution of the Poincare Conjecture, this is a different way toward it. Given a simply connected, closed 3-manifold M, we produce a homotopy disc H, which arises from M by a finite sequence of simple modifications and, almost miraculously, can be imbedded into the ordinary space R^3. It follows that H is a disc, hence M is a sphere. I

Kimball A. Milton, Jef Wagner, Prachi Parashar, Iver Brevik

Despite suggestions to the contrary, we show in this paper that the usual dispersive form of the electromagnetic energy must be used to derive the Lifshitz force between parallel dielectric media. This conclusion follows from the general form of the quantum vacuum energy, which is the basis of the multiple-scattering formalism. As an illustration, we explici

Andrii Goriunov, Vladimir Mikhailets

In this paper we consider the Sturm-Liuoville operator in the Hilbert space $L_2$ with the singular complex potential of $W^{-1}_2$ and two-point boundary conditions. For this operator we give sufficient conditions for norm resolvent approximation by the operators of the same class.

Iwo Bialynicki-Birula, Zofia Bialynicka-Birula

We propose a simple three-body model of an atom in which one electron on a circular Rydberg orbit is treated as an independent particle and the remaining core electrons are collectively described as a single object. Within this model we predict the existence of stable deformed states of atoms. The deformation is generated by a bootstrap mechanism. The atomic

A. Abdollahi, H. Khosravi

We prove that the set of right 4-Engel elements of a group $G$ is a subgroup for locally nilpotent groups $G$ without elements of orders 2, 3 or 5; and in this case the normal closure $<x>^G$ is nilpotent of class at most 7 for each right 4-Engel elements $x$ of $G$.

Urmas Haud

In the previous papers of this series, we have decomposed into Gaussian components all the HI 21-cm line profiles of the Leiden-Argentina-Bonn (LAB) database, and studied statistical distributions of the obtained Gaussians. Now we are interested in separation from the general database of the components the &#34;clouds&#34; of closely spaced similar Gaussians

V. A. Fedotov, J. -H. Shi, A. Tsiatmas, P. de Groot

We demonstrate a millimeter-wave range metamaterial fabricated from cuprate superconductor. Two complementary metamaterial structures have been studied, which exhibit Fano resonances emerging from the collective excitation of interacting magnetic and electric dipole modes.

Fedor V. Prigara

It is shown that a ferroelastic lattice distortion is associated with the superconducting transition both in low- and high-temperature superconductors. In layered tetragonal superconductors with a sufficiently high transition temperature, a ferroelastic distortion is improper and is caused by an out-of-plane charge ordering. The relation between the out-of-p

Vladimir G. Ivancevic

Recently, a novel adaptive wave model for financial option pricing has been proposed in the form of adaptive nonlinear Schrödinger (NLS) equation [Ivancevic a], as a high-complexity alternative to the linear Black-Scholes-Merton model [Black-Scholes-Merton]. Its quantum-mechanical basis has been elaborated in [Ivancevic b]. Both the solitary and shock-wave s

Jean-Guillaume Dumas, Thierry Gautier, Jean-Louis Roch

We propose a generic design for Chinese remainder algorithms. A Chinese remainder computation consists in reconstructing an integer value from its residues modulo non coprime integers. We also propose an efficient linear data structure, a radix ladder, for the intermediate storage and computations. Our design is structured into three main modules: a black bo

Kh. Saaidi, A. Vaji, A. Aghamomammadi

The static spherically symmetric solution for (R +- μ^4/R) model of f(R)gravity is investigated. We obtain the metric for space-time in the solar system that reduces to the Schwarzschild metric, when μ tends to zero. For the obtained metric, the deviation from Einstein gravity is very small. This result is different from the other results have been obtained

A. Aghamohammadi, Kh. Saaidi, M. R. Abolhasani, A. Vajdi

A static, asymptotically flat, spherically symmetric solutions is investigated in f(R) theories of gravity for a charged black hole. We have studied the weak field limit of f(R) gravity for the some f(R) model such as f(R) = R + epsilon h(R). In particular, weconsider the case lim_{R =0} {h(R)/ dh(R)/dR}=0 and find the space time metric for f(R) = R + {mu}^{

Winfried Bruns, Raymond Hemmecke, Bogdan Ichim, Matthias Koeppe

In this paper we present two independent computational proofs that the monoid derived from $5\times 5\times 3$ contingency tables is normal, completing the classification by Hibi and Ohsugi. We show that Vlach&#39;s vector disproving normality for the monoid derived from $6\times 4\times 3$ contingency tables is the unique minimal such vector up to symmetry.

Alessandro Betti, Gianluca Fiori, Giuseppe Iannaccone

We predict shot noise enhancement in defect-free carbon nanotube field-effect transistors through a numerical investigation based on the self-consistent solution of the Poisson and Schrodinger equations within the non-equilibrium Green functions formalism, and on a Monte Carlo approach to reproduce injection statistics. Noise enhancement is due to the correl

G. M. Bruun, C. J. Pethick, Zhenhua Yu

We consider the absorption spectrum of a Fermi gas mixed with a minority species when majority fermions are transferred to another internal state by an external probe. In the limit when the minority species is much more massive than the majority one, we show that the minority species may be treated as static impurities and the problem can be solved in closed

Alexander Sakhnovich

Initial-boundary value problems for complex sine-Gordon and sine-Gordon equations in a semi--strip are treated. The evolution of the Weyl function and a uniqueness result are obtained for complex sine-Gordon equation. The evolution of the Weyl function as well as an existence result and a procedure to recover solution are given for sine-Gordon equation. It i

Dakshina Ranjan Kisku, Hunny Mehrotra, Jamuna Kanta Sing, Phalguni Gupta

Identity verification of authentic persons by their multiview faces is a real valued problem in machine vision. Multiview faces are having difficulties due to non-linear representation in the feature space. This paper illustrates the usability of the generalization of LDA in the form of canonical covariate for face recognition to multiview faces. In the prop

Casey Meakin, David Arnett

We investigate simulated turbulent flow within thermally driven stellar convection zones. Different driving sources are studied, including cooling at the top of the convectively unstable region, as occurs in surface convection zones; and heating at the base by nuclear burning. The transport of enthalpy and kinetic energy, and the distribution of turbulent ki

K. Lakshmi Madhuri, T. R. Gopalakrishnan Nair

Authentication and authorization are two tightly coupled and interrelated concepts which are used to keep transactions secure and help in protecting confidential information. This paper proposes to evaluate the current techniques used for authentication and authorization also compares them with the best practices and universally accepted authentication and a

P. Jayarekha, T. R. Gopalakrishnan Nair

In this paper we have proposed an adaptive dynamic cache replacement algorithm for a multimedia servers cache system. The goal is to achieve an effective utilization of the cache memory which stores the prefix of popular videos. A replacement policy is usually evaluated using hit ratio, the frequency with which any video is requested. Usually discarding the

Asoka Biswas, Moshe Shapiro, Paul Brumer

Overlapping resonances are shown to provide new insights into the extent of decoherence experienced by a system superposition state in the regime of strong system- environment coupling. As an example of this general approach, a generic system comprising spin-half particles interacting with a thermalized oscillator environment is considered. We find that (a)