February 2010 arXiv papers — page 34

Sven Krippendorf, Matthew J. Dolan, Anshuman Maharana, Fernando Quevedo

We discuss general properties of D-brane model building at toric singularities. Using dimer techniques to obtain the gauge theory from the structure of the singularity, we extract results on the matter sector and superpotential of the corresponding gauge theory. We show that the number of families in toric phases is always less than or equal to three, with a

Mark E. Perel'man

At passage of 21-cm pulsar radiation through clouds of neutral hydrogen atoms the signal in the region of anomalous dispersion is appearing as faster-than-c. As unlike laboratory researches separate scatterers are located on big distances from each other, this effect can be attributed only to the consecutive independent scattering on isolated atoms. For its

Arne Goedeke, Alan D. Rendall

It is known that all spatially homogeneous solutions of the vacuum Einstein equations in four dimensions which exist for an infinite proper time towards the future are future geodesically complete. This paper investigates whether the analogous statement holds in higher dimensions. A positive answer to this question is obtained for a large class of models whi

A. M. Polubotko

The paper demonstrates possibility of giant enhancement of Surface Enhanced Hyper Raman Scattering on the base of qualitative consideration of electromagnetic field near some models of rough metal surfaces and of some features of the dipole and quadrupole light-molecule interaction, such as it was made in the dipole-quadrupole SERS theory. Consideration of s

G. Duplancic, D. Glavan, H. Stefancic

As the vacuum state of a quantum field is not an eigenstate of the Hamiltonian density, the vacuum energy density can be represented as a random variable. We present an analytical calculation of the probability distribution of the vacuum energy density for real and complex massless scalar fields in Minkowski space. The obtained probability distributions are

H. Okabe, N. Takeshita, K. Horigane, T. Muranaka

In this study, we performed high-pressure electrical resistivity measurements of polycrystalline FeSe in the pressure range of 1-16.0 GPa at temperatures of 4-300 K. A precise evaluation of Tc from zero-resistivity temperatures revealed that Tc shows a slightly distorted dome-shaped curve, with maximum Tc (30 K) at 6 GPa, which is lower than a previously rep

M. O. Hase, T. Tomé, M. J. de Oliveira

A generalized version of the nonequilibrium linear Glauber model with $q$ states in $d$ dimensions is introduced and analyzed. The model is fully symmetric, its dynamics being invariant under all permutations of the $q$ states. Exact expressions for the two-time autocorrelation and response functions on a $d$-dimensional lattice are obtained. In the stationa

F. Thüroff, F. Wagner, E. Frey

The constraints imposed by nano- and microscale confinement on the conformational degrees of freedom of thermally fluctuating biopolymers are utilized in contemporary nano-devices to specifically elongate and manipulate single chains. A thorough theoretical understanding and quantification of the statistical conformations of confined polymer chains is thus a

Conrad Lee, Fergal Reid, Aaron McDaid, Neil Hurley

In complex networks it is common for each node to belong to several communities, implying a highly overlapping community structure. Recent advances in benchmarking indicate that existing community assignment algorithms that are capable of detecting overlapping communities perform well only when the extent of community overlap is kept to modest levels. To ove

Jacopo Bellazzini, Gaetano Siciliano

We prove the existence of orbitally stable standing waves with prescribed $L^2$-norm for the following Schrödinger-Poisson type equation \label{intro} %{%{ll} iψ_{t}+ Δψ- (|x|^{-1}*|ψ|^{2}) ψ+|ψ|^{p-2}ψ=0 \text{in} \R^{3}, %-Δϕ= |ψ|^{2}& \text{in} \R^{3},%. when $p\in \{8/3\}\cup (3,10/3)$. In the case $3<p<10/3$ we prove the existence and stability only for

Alexander V. Kolesnikov, Roman I. Zhdanov

We study the isoperimetric problem for the radially symmetric measures. Applying the spherical symmetrization procedure and variational arguments we reduce this problem to a one-dimensional ODE of the second order. Solving numerically this ODE we get an empirical description of isoperimetric regions of the planar radially symmetric exponential power laws. We

Guillaume Dumont, Paul Boulanger, Michel Côté, Matthias Ernzerhof

We present a first-principles study of Peierls distortions in \emph{trans}-polyacetylene, polyacene, and armchair $(n,n)$ carbon nanotubes. Our findings suggest that the ground-state geometries of armchair $(n,n)$ carbon nanotubes, with $n$ up to 6, exhibit a Peierls distortion as it is found for \emph{trans}-polyactetylene. In contrast to previous studies i

M. Gibert, H. Xu, E. Bodenschatz

We report experimental results on the relative motion of pairs of solid spheric particles with initial separations in the inertial range of fully developed turbulence in water. The particle densities were in the range of $1 \lessapprox ρ_{p}/ρ_{f} \lessapprox 8$, \textit{i.e.}, from neutrally buoyant to highly inertial; and their sizes were of the Kolmogorov

Ozan S. Sarıyer, Michael Hinczewski, A. Nihat Berker

The global phase diagram of the spinless Falicov-Kimball model in d = 3 spatial dimensions is obtained by renormalization-group theory. This global phase diagram exhibits five distinct phases. Four of these phases are charge-ordered (CO) phases, in which the system forms two sublattices with different electron densities. The CO phases occur at and near half

A. I. Safonov, I. I. Safonova, S. S. Demukh

The low-temperature dc mobility of the two-dimensional electron system localized above the surface of superfluid helium is determined by the slowest stage of the longitudinal momentum transfer to the bulk liquid, namely, by the interaction of surface and volume excitations of liquid helium, which rapidly decreases with temperature. Thus, the temperature depe

Jörg Hennig, Gernot Neugebauer

We resume former discussions of the question, whether the spin-spin repulsion and the gravitational attraction of two aligned sub-extremal black holes can balance each other. To answer the question we formulate a boundary value problem for two separate (Killing-) horizons and apply the inverse (scattering) method to solve it. Making use of a universal inequa

Axel Freyn, Martina Flöser, Régis Mélin

Predictions are established for linear differential current-current cross-correlations dSab/dV in a symmetrically biased three-terminal normal metal-superconductor-normal metal (NSN) device. Highly transparent contacts turn out to be especially interesting because they feature positive dSab/dV. At high transparency, processes based on Crossed Andreev Reflect

Tobias Verhulst, Jan Naudts

We start from a Hamiltonian describing non-interacting fermions and add bosons to the model, with a Jaynes-Cummings-like interaction between the bosons and fermions. Because of the specific form of the interaction the model can be solved exactly. In the ground state, part of the electrons form bound pairs with opposite momentum and spin. The model also shows

Alberto Anfossi, Luca Barbiero, Arianna Montorsi

Strongly interacting fermionic atoms on optical lattices are studied through a Hubbard-like model Hamiltonian, in which tunneling rates of atoms and molecules between neighboring sites are assumed to be different. In the limit of large onsite repulsion U, the model is shown to reproduce the t-J Hamiltonian, in which the J coefficient of the Heisenberg term d

Øystein Rudjord, Nicolaas E. Groeneboom, Frode K. Hansen, Paolo Cabella

Using the 5 year WMAP data, we re-investigate claims of non-Gaussianities and asymmetries detected in local curvature statistics of the 1 year WMAP data. In Hansen et al 2004, it was found that the northern ecliptic hemisphere was non-Gaussian at the ~1% level testing the densities of hill-, lake and saddle points based on the second derivatives of the CMB t

Domenico Pacini

At the beginning of the twentieth century, two scientists, the Austrian Victor Hess and the Italian Domenico Pacini, developed two brilliant lines of research independently, leading to the determination of the origin of atmospheric radiation. Before their work, the origin of the radiation today called &#34;cosmic rays&#34; was strongly debated, as many scien

Avto Tavkhelidze

Recently, new quantum features have been studied in the area of ridged quantum wells (RQW). Periodic ridges on the surface of the quantum well layer impose additional boundary conditions on the electron wave function and reduce the quantum state density. Electrons, rejected from forbidden quantum states, have to occupy the states with higher energy. As a res

Andrew King

I review accretion and outflow in active galactic nuclei. Accretion appears to occur in a series of very small--scale, chaotic events, whose gas flows have no correlation with the large--scale structure of the galaxy or with each other. The accreting gas has extremely low specific angular momentum and probably represents only a small fraction of the gas invo

Jean-Baptiste Meilhan, Akira Yasuhara

We give formulas expressing Milnor invariants of an n-component link L in the 3-sphere in terms of the HOMFLYPT polynomial as follows. If the Milnor invariant \barμ_J(L) vanishes for any sequence J with length at most k, then any Milnor \barμ-invariant \barμ_I(L) with length between 3 and 2k+1 can be represented as a combination of HOMFLYPT polynomial of kno

Abed Bounemoura

A major result concerning perturbations of integrable Hamiltonian systems is given by Nekhoroshev estimates, which ensures exponential stability of all solutions provided the system is analytic and the integrable Hamiltonian not too degenerate. In the particular but important case where the latter is quasi-convex, these exponential estimates have been genera

Sho Nishino, Yasushi Fukazawa, Katsuhiro Hayashi, Kazuhiro Nakazawa

We report on a study of the large-scale temperature structure of the Perseus cluster with Suzaku, using the observational data of four pointings of 30&#39; offset regions, together with the data from the central region. Thanks to the Hard X-ray Detector (HXD-PIN: 10 - 60 keV), Suzaku can determine the temperature of hot galaxy clusters. We performed the spec

P. W. Zhao, Z. P. Li, J. M. Yao, J. Meng

A new parametrization PC-PK1 for the nuclear covariant energy density functional with nonlinear point-coupling interaction is proposed by fitting to observables for 60 selected spherical nuclei, including the binding energies, charge radii and empirical pairing gaps. The success of PC-PK1 is illustrated in its description for infinite nuclear matter and fini

Iulia Buluta, Sahel Ashhab, Franco Nori

Remarkable progress towards realizing quantum computation has been achieved using natural and artificial atoms as qubits. This article presents a brief overview of the current status of different types of qubits. On the one hand, natural atoms (such as neutral atoms and ions) have long coherence times, and could be stored in large arrays, providing ideal &#3

Masahito Yamazaki

This paper summarizes recent developments in the theory of Bogomol&#39;nyi-Prasad-Sommerfield (BPS) state counting and the wall crossing phenomena, emphasizing in particular the role of the statistical mechanical model of crystal melting. This paper is divided into two parts, which are closely related to each other. In the first part, we discuss the statisti

Daniel Golovin, Matthew Faulkner, Andreas Krause

A key problem in sensor networks is to decide which sensors to query when, in order to obtain the most useful information (e.g., for performing accurate prediction), subject to constraints (e.g., on power and bandwidth). In many applications the utility function is not known a priori, must be learned from data, and can even change over time. Furthermore for

Gerald Hoehn, Ching Hung Lam, Hiroshi Yamauchi

E7 part: In this paper, we study McKay&#39;s E7 observation on the Baby Monster. By investigating so called derived c=7/10 Virasoro vectors, we show that there is a natural correspondence between dihedral subgroups of the Baby Monster and certain subalgebras of the Baby Monster vertex operator algebra which are constructed by the nodes of the affine E7 diagr

Robert Braun, George Heald, Rainer Beck

A sample of large northern Spitzer Infrared Nearby Galaxies Survey (SINGS) galaxies was recently observed with the Westerbork Synthesis Radio Telescope (WSRT) at 1300-1760 MHz. In Paper II of this series, we described sensitive observations of the linearly polarized radio continuum emission in this WSRT-SINGS galaxy sample. Here we explore the systematic pat

Luc Menichi

Let $H$ be a Hopf algebra with a modular pair in involution $(\Character,1)$. Let $A$ be a (module) algebra over $H$ equipped with a non-degenerated $\Character$-invariant $1$-trace $τ$. We show that Connes-Moscovici characteristic map $φ_τ:HC^*_{(\Character,1)}(H)\rightarrow HC^*_λ(A)$ is a morphism of graded Lie algebras. We also have a morphism $Φ$ of Bat

Q. P. Liu, Ziemowit Popowicz, Kai Tian

The supersymmetric analog of the reciprocal transformation is introduced. This is used to establish a transformation between one of the supersymmetric Harry Dym equations and the supersymmetric modified Korteweg-de Vries equation. The reciprocal transformation, as a Bäcklund-type transformation between these two equations, is adopted to construct a recursion

David Baraglia

We study the Hitchin component in the space of representations of the fundamental group of a Riemann surface into a split real simple Lie group in the rank 2 case. We prove that such representations are described by a conformal structure and class of Higgs bundle we call cyclic and we show cyclic Higgs bundles correspond to a form of the affine Toda equation

Xinpeng Li

This paper investigates the strict comparison theorem under the framework of $G$-expectation, i.e., let $X\leq Y$ q.s., if $X,Y$ satisfy some additional conditions, then $\E[X]<\E[Y]$.

Vittorio Addona, Stan Wagon, Herb Wilf

Suppose Alice has a coin with heads probability $q$ and Bob has one with heads probability $p>q$. Now each of them will toss their coin $n$ times, and Alice will win iff she gets more heads than Bob does. Evidently the game favors Bob, but for the given $p,q$, what is the choice of $n$ that maximizes Alice&#39;s chances of winning? The problem of determining

Eugene B. Kolomeisky, Joseph P. Straley, Luke S. Langsjoen, Hussain Zaidi

The Casimir self-energy of a boundary is ultraviolet-divergent. In many cases the divergences can be eliminated by methods such as zeta-function regularization or through physical arguments (ultraviolet transparency of the boundary would provide a cutoff). Using the example of a massless scalar field theory with a single Dirichlet boundary we explore the rel

Jing-Rong Wang, Guo-Zhu Liu

The damping rate of two-dimensional massless Dirac fermions exhibit non-Fermi liquid behavior, $\propto ε^{1/2}$, due to gauge field at zero temperature and zero chemical potential. We study the fate of this behavior at finite chemical potential. We fist calculate explicitly the temporal and spatial components of vacuum polarization functions. The analytical

Ping Ronggang

We present recent results from the BES experiment on the observation of the Y(2175) in $J/ψ\to ϕf_0(980) η$, and $η(2225)$ in $J/ψ\to γϕϕ$, and X(1440) in $J/ψ$ hadronic decays, together with the new observation of $ψ(2S)$ radiative decays and hadronic decays into $n\ks\ldb+c.c., \ld\ldbπ^0, \ld\ldbη$. The effort to search for $J/ψ$ decays into $γγ$ and invi

Pavel Fileviez Perez, Mark B. Wise

We investigate a simple theory where Baryon number (B) and Lepton number (L) are local gauge symmetries. In this theory B and L are on the same footing and the anomalies are cancelled by adding a single new fermionic generation. There is an interesting realization of the seesaw mechanism for neutrino masses. Furthermore, there is a natural suppression of fla

Michael D. Schneider, Oskar Holm, Lloyd Knox

Simulation design is the choice of locations in parameter space at which simulations are to be run and is the first step in building an emulator capable of quickly providing estimates of simulation results for arbitrary locations in the parameter space. We introduce an alteration to the &#34;OALHS&#34; design used by Heitmann et al. (2006) that reduces the n

Sol H. Jacobsen, P. D. Jarvis

We study the relationship between one-dimensional fermion gas-impurity models and quantum dissipative systems, via the method of constructive bosonisation and unitary transformation. Starting from an anisotropic Coqblin-Schrieffer model, a new, exactly solvable, three-level quantum dissipative system is derived as a generalisation of the standard spin-half s

G. Windmiller, J. A. Orosz, P. B. Etzel

GU Boo is one of only a relatively small number of well studied double-lined eclipsing binaries that contain low-mass stars. L&#39;opez-Morales & Ribas (2005, hereafter LR05) present a comprehensive analysis of multi-color light and radial velocity curves for this system. The GU Boo light curves presented in LR05 had substantial asymmetries, which were attri

Patrick M. Young, Per-Gunnar Martinsson

A scheme for rapidly and accurately computing solutions to boundary integral equations (BIEs) on rotationally symmetric surfaces in three dimensions is presented. The scheme uses the Fourier transform to reduce the original BIE defined on a surface to a sequence of BIEs defined on a generating curve for the surface. It can handle loads that are not necessari

Adrian Carbajal-Dominguez, J. Bernal, Jesus E. Gomez Correa, Gabriel Martinez Niconoff

t is a known fact that near field diffraction or Fresnel diffraction calculations are difficult to perform exactly. It is in general necessary to make some approximations in order to obtain a more suitable form. In this work, a numerical implementation based on angular spectrum theory for near field diffraction is presented. The method uses Fast Fourier Tran

Andrey Itkin, Peter Carr

In mathematical finance a popular approach for pricing options under some Levy model is to consider underlying that follows a Poisson jump diffusion process. As it is well known this results in a partial integro-differential equation (PIDE) that usually does not allow an analytical solution while numerical solution brings some problems. In this paper we elab

Martin Asplund, Karin Lind

In this review we discuss possible systematic errors inherent in classical 1D LTE abundance analyses of late-type stars for the light elements (here: H, He, Li, Be and B). The advent of realistic 3D hydrodynamical model atmospheres and the availability of non-LTE line formation codes place the stellar analyses on a much firmer footing and indeed drastically

G. Andonian, E. Hemsing, A. Murokh, M. Dunning

The use of coherent transition radiation autocorrelation methods to determine bunch length and profile information is examined with the compressed electron beam at the BNL ATF. A bi-gaussian fit is applied to coherent transition radiation auto-correlation data to extract the longitudinal current distribution. The effects of large transverse beam sizes are st

J. D. Rameau, H. -B. Yang, G. D. Gu, P. D. Johnson

Laser based photoemission with photons of energy 6 eV is used to examine the fine details of the very low energy electron dispersion and associated dynamics in the nodal region of optimally doped Bi2212. A &#34;kink&#34; in the dispersion in the immediate vicinity of the Fermi energy is associated with scattering from an optical phonon previously identified

Frederick Tremblay, Pavel Winternitz

A complete classification is presented of quantum and classical superintegrable systems in $E_2$ that allow the separation of variables in polar coordinates and admit an additional integral of motion of order three in the momentum. New quantum superintegrable systems are discovered for which the potential is expressed in terms of the sixth Painlevé transcend

Sandra Dussan, Ashok Kumar, J. F. Scott, Ram S. Katiyar

PbZr0.52Ti0.48O3/La0.67Sr0.33MnO3(PZT/LSMO) bilayer with surface roughness ~ 1.8 nm thin films have been grown by pulsed laser deposition on LaAlO3(LAO) substrates. High remnant polarization (30-54 micro C/cm2), dielectric constant(400-1700), and well saturated magnetization were observed depending upon the deposition temperature of the ferromagnetic layer a

J. T. Stewart, J. P. Gaebler, T. E. Drake, D. S. Jin

Many-body fermion systems are important in many branches of physics, including condensed matter, nuclear, and now cold atom physics. In many cases, the interactions between fermions can be approximated by a contact interaction. A recent theoretical advance in the study of these systems is the derivation of a number of exact universal relations that are predi

Chaomei Chen, Fidelia Ibekwe-SanJuan, Jianhua Hou

A multiple-perspective co-citation analysis method is introduced for characterizing and interpreting the structure and dynamics of co-citation clusters. The method facilitates analytic and sense making tasks by integrating network visualization, spectral clustering, automatic cluster labeling, and text summarization. Co-citation networks are decomposed into

Li Shu-Yue, Yan Feng-Li

Based on resonant sideband excitation, we present a scheme for the generation of six-qubit cluster state in ion-trap system. One can realize experimentally this scheme with presently available techniques.

Lindsay B. H. May, Michael Shearer, Karen E. Daniels

Granular materials will segregate by particle size when subjected to shear, as occurs, for example, in avalanches. The evolution of a bidisperse mixture of particles can be modeled by a nonlinear first order partial differential equation, provided the shear (or velocity) is a known function of position. While avalanche-driven shear is approximately uniform i

Tao Yan, Fengli Yan

We present a quantum key distribution protocol based on four-level particles entanglement. Furthermore, a controlled quantum key distribution protocol is proposed by utilizing three four-level particles. We show that the two protocols are secure.

Lian Shi-Man, Yan Feng-Li

We propose a scheme for probabilistic teleportation of an unknown two-particle state of general formation in ion trap. It is shown that one can realize experimentally this teleportation protocol of two-particle state with presently available techniques.

J. B. Rosenzweig, G. Andonian, P. Bucksbaum, M. Ferrario

Recent initiatives in ultra-short, GeV electron beam generation have focused on achieving sub-fs pulses for driving X-ray free-electron lasers (FELs) in single-spike mode. This scheme employs very low charge beams, which may allow existing FEL injectors to produce few-100 as pulses, with high brightness. Towards this end, recent experiments at SLAC have prod

The Pierre Auger Collaboration

We report a measurement of the flux of cosmic rays with unprecedented precision and statistics using the Pierre Auger Observatory. Based on fluorescence observations in coincidence with at least one surface detector we derive a spectrum for energies above 10^18 eV. We also update the previously published energy spectrum obtained with the surface detector arr

Matthew A. Taylor, Thomas H. Puzia, Gretchen L. Harris, William E. Harris

Velocity dispersion measurements are presented for luminous GCs in NGC 5128 derived from high-res. UVES spectra. The measurements are made with the pPXF code that parametrically recovers line-of-sight velocity dispersions. Combining the measured velocity dispersions with surface photometry and structural parameter data from HST enables both dynamical masses

A. Buzzoni, L. Patelli, M. Bellazzini, F. Fusi Pecci

We have investigated the relevant trend of the bolometric correction (BC) at the cool-temperature regime of red giant stars and its possible dependence on stellar metallicity. Our analysis relies on a wide sample of optical-infrared spectroscopic observations, along the 3500A-2.5micron wavelength range, for a grid of 92 red giant stars in five (3 globular +

Francesco Voltolina

The work presented in this Tesi di Laurea arises from a collaboration between the IPL (Image Processing Laboratory) of the Dipartimento di Elettrotecnica, Elettronica ed Informatica (DEEI) at the University of Trieste and the Instrumentation and Detector Laboratory belonging to the ELETTRA Synchrotron Light Source of Trieste. Under the European Contract ERBF

H. Schunker, R. Cameron, L. Gizon

In local helioseismology numerical simulations of wave propagation are useful to model the interaction of solar waves with perturbations to a background solar model. However, the solution to the equations of motions include convective modes that can swamp the waves we are interested in. For this reason, we choose to first stabilise the background solar model

L. X. Gutierrez-Guerrero, A. Bashir, I. C. Cloet, C. D. Roberts

In a Poincare&#39;-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a momentum-independent interaction, regularised in a symmetry-preserving manner. The contact interaction, whilst capable of descri

Rahul Nandkishore, Leonid Levitov

We analyze competition between different ordered states in bilayer graphene (BLG). Combining arguments based on SU(4) spin-valley flavor symmetry with a mean field analysis, we identify the lowest energy state with the anomalous Hall insulator (AHI). This state is an SU(4) singlet excitonic insulator with broken time reversal symmetry, exhibiting quantized H

Oliver Hahn, Romain Teyssier, C. Marcella Carollo

We use a 380 h-1 pc resolution hydrodynamic AMR simulation of a cosmic filament to investigate the orientations of a sample of ~100 well-resolved galactic disks spanning two orders of magnitude in both stellar and halo mass. We find: (i) At z=0, there is an almost perfect alignment at a median angle of 18 deg, in the inner dark matter halo regions where the

E. Carretta, A. Bragaglia, R. G. Gratton, S. Lucatello

We derive homogeneous abundances of Fe, O, Na and alpha-elements from high resolution FLAMES spectra for 76 red giant stars in NGC 6715 (M 54) and for 25 red giants in the surrounding nucleus of the Sagittarius (Sgr) dwarf galaxy. Our main findings are that: (i) we confirm that M 54 shows intrinsic metallicity dispersion, ~0.19 dex r.m.s.; (ii) when the star

Simon Portegies Zwart, Steve McMillan, Mark Gieles

Young massive clusters are dense aggregates of young stars that form the fundamental building blocks of galaxies. Several examples exist in the Milky Way Galaxy and the Local Group, but they are particularly abundant in starburst and interacting galaxies. The few young massive clusters that are close enough to resolve are of prime interest for studying the s

A. R. Offringa, A. G. de Bruyn, M. Biehl, S. Zaroubi

We describe and compare several post-correlation radio frequency interference classification methods. As data sizes of observations grow with new and improved telescopes, the need for completely automated, robust methods for radio frequency interference mitigation is pressing. We investigated several classification methods and find that, for the data sets we

K. K. Guatam, Anurag Rai

Over the recent years a considerable amount of effort has been devoted towards the performance evaluation and prediction of Mobile Networks. Performance modeling and evaluation of mobile networks are very important in view of their ever expending usage and the multiplicity of their component parts together with the complexity of their functioning. The presen

Hadj Zerrouki, Mohamed Feham

WiMAX technology is based on the IEEE 802.16 specification of which IEEE 802.16-2004 and 802.16e amendment are Physical (PHY) layer specifications. IEEE 802.16-2004 currently supports several multiple-antenna options including Space-Time Codes (STC), Multiple-Input Multiple-Output (MIMO) antenna systems and Adaptive Antenna Systems (AAS). The most recent WiM

Dr. R. Shashikumar, C. N. Vijay Kumar, M. Nagendrakumar, C. S. Hemanthkumar

DDR SDRAM is similar in function to the regular SDRAM but doubles the bandwidth of the memory by transferring data on both edges of the clock cycles. DDR SDRAM most commonly used in various embedded application like networking, image or video processing, Laptops ete. Now a days many applications needs more and more cheap and fast memory. Especially in the fi

Mr. Kondekar V. H., Mr. Kolkure V. S., Prof. Kore S. N

The purpose of this Paper is to describe our research on different feature extraction and matching techniques in designing a Content Based Image Retrieval (CBIR) system. Due to the enormous increase in image database sizes, as well as its vast deployment in various applications, the need for CBIR development arose. Firstly, this paper outlines a description

Syed, M. Rahman, Shannon E. Donahue

As physical and information security boundaries have become increasingly blurry many organizations are experiencing challenges with how to effectively and efficiently manage security within the corporate. There is no current standard or best practice offered by the security community regarding convergence; however many organizations such as the Alliance for

Jon Magne Leinaas, Jan Myrheim, Per Oyvind Sollid

We report here on the results of numerical searches for PPT states with specified ranks for density matrices and their partial transpose. The study includes several bipartite quantum systems of low dimensions. For a series of ranks extremal PPT states are found. The results are listed in tables and charted in diagrams. Comparison of the results for systems o

N. Stojilovic, A. Koncz, L. W. Kohlman, Rongwei Hu

We have used optical spectroscopy to probe the normal state electrodynamic response of Fe$_{1.06}$Te$_{0.88}$S$_{0.14}$, a member of the 11 family of iron-based superconductors with T$_c$= 8 K. Measurements have been conducted over a wide frequency range (50 - 50000 cm$^{-1}$) at selected temperatures between 10 and 300 K. At low temperatures the material be

F. F. Rosales-Ortega, R. C. Kennicutt, S. F. Sanchez, A. I. Diaz

We present the PPAK Integral Field Spectroscopy (IFS) Nearby Galaxies Survey: PINGS, a 2-dimensional spectroscopic mosaicking of 17 nearby disk galaxies in the optical wavelength range. This project represents the first attempt to obtain continuous coverage spectra of the whole surface of a galaxy in the nearby universe. The final data set comprises more tha

D. Cogollo, H. Diniz, C. A. de S. Pires

On fitting the type II seesaw mechanism into the type I seesaw mechanism, we obtain a formula to the neutrino masses which get suppressed by high-scale $M^3$ in its denominator. As a result, light neutrinos are naturally obtained with new physics at TeV scale. As interesting consequence, the mechanism may be directly probed at the LHC by directly producing t

Maria Deijfen, Olle Haggstrom, Alexander E. Holroyd

Let each point of a homogeneous Poisson process in R^d independently be equipped with a random number of stubs (half-edges) according to a given probability distribution mu on the positive integers. We consider translation-invariant schemes for perfectly matching the stubs to obtain a simple graph with degree distribution mu. Leaving aside degenerate cases,

Dimitris Kugiumtzis, Alkiviadis Tsimpiris

In many applications, such as physiology and finance, large time series data bases are to be analyzed requiring the computation of linear, nonlinear and other measures. Such measures have been developed and implemented in commercial and freeware softwares rather selectively and independently. The Measures of Analysis of Time Series ({\tt MATS}) {\tt MATLAB}

Yukio Tomozawa

A prediction and observational evidence for the mass of a dark matter particle are presented..

Brittany Terese Fasy

Persistence homology is a tool used to measure topological features that are present in data sets and functions. Persistence pairs births and deaths of these features as we iterate through the sublevel sets of the data or function of interest. I am concerned with using persistence to characterize the difference between two functions f, g : M -> R, where M is

Chaomei Chen, Jian Zhang, Michael S. Vogeley

We introduce a new visual analytic approach to the study of scientific discoveries and knowledge diffusion. Our approach enhances contemporary co-citation network analysis by enabling analysts to identify co-citation clusters of cited references intuitively, synthesize thematic contexts in which these clusters are cited, and trace how research focus evolves

Yago Antolín, Warren Dicks, Peter A. Linnell

For a group $H$ and a subset $X$ of $H$, we let ${}^HX$ denote the set $\{hxh^{-1} \mid h \in H, x \in X\}$, and when $X$ is a free-generating set of $H$, we say that the set ${}^HX$ is a Whitehead subset of $H$. For a group $F$ and an element $r$ of $F$, we say that $r$ is Cohen-Lyndon aspherical in $F$ if ${}^F\{r\}$ is a Whitehead subset of the subgroup o

A. Alonso Izquierdo, M. Á. González León, M. de la Torre Mayado

The solitary waves of massive (1+1)-dimensional nonlinear S^N-sigma models are unveiled. It is shown that the solitary waves in these systems are in one-to-one correspondence with the separatrix trajectories in the repulsive N-dimensional Neumann mechanical problem. There are topological (heteroclinic trajectories) and non-topological (homoclinic trajectorie

Jatindranath Gain, Madhumita Das Sarkar, Sudakshina Kundu

Tunneling of electrons through the barriers in heterostructures has been studied, within unified transfer matrix approach. The effect of barrier width on the transmission coefficient of the electrons has been investigated for different pairs of semi conducting materials that are gaining much importance recently. These pairs include CdS/CdSe, AlGaAs/GaAs and

Fernando Galve, Gian Luca Giorgi, Roberta Zambrini

We study the evolution of entanglement of a pair of coupled, non-resonant harmonic oscillators in contact with an environment. For both the cases of a common bath and of two separate baths for each of the oscillators, a full master equation is provided without rotating wave approximation. This allows us to characterize the entanglement dynamics as a function

Jozsef Balogh, Dhruv Mubayi

The neighborhood of a pair of vertices $u,v$ in a triple system is the set of vertices $w$ such that $uvw$ is an edge. A triple system $\HH$ is semi-bipartite if its vertex set contains a vertex subset $X$ such that every edge of $\HH$ intersects $X$ in exactly two points. It is easy to see that if $\HH$ is semi-bipartite, then the neighborhood of every pair

W. Knafo, D. Aoki, D. Vignolles, B. Vignolle

A study of the antiferromagnet CeRh$_2$Si$_2$ by torque, magnetostriction, and transport in pulsed magnetic fields up to 50 Tesla and by thermal expansion in static fields up to 13 Tesla is presented. The magnetic field-temperature phase diagram of CeRh$_2$Si$_2$, where the magnetic field is applied along the easy axis $\mathbf{c}$, is deduced from these mea

M. J. White, F. Feroz

We examine the case of neutralino dark matter in the focus point region of the MSSM, in which the scalar sparticles are too heavy to be produced at the LHC. Whilst it has been previously asserted that the LHC alone would fail to constrain the properties of the lightest neutralino for such a scenario, we find that one can obtain good predictions of astrophysi

Luitpold Babel, Irina V. Chuvaeva, Mikhail Klin, Dmitrii V. Pasechnik

The stabilization algorithm of Weisfeiler and Leman has as an input any square matrix A of order n and returns the minimal cellular (coherent) algebra W(A) which includes A. In case when A=A(G) is the adjacency matrix of a graph G the algorithm examines all configurations in G having three vertices and, according to this information, partitions vertices and

K. Jensen, W. Wasilewski, H. Krauter, T. Fernholz

A quantum memory for light is a key element for the realization of future quantum information networks. Requirements for a good quantum memory are (i) versatility (allowing a wide range of inputs) and (ii) true quantum coherence (preserving quantum information). Here we demonstrate such a quantum memory for states possessing Einstein-Podolsky-Rosen (EPR) ent

Hansjörg Lipp, Michael Engel, Steffen Sonntag, Hans-Rainer Trebin

In quasicrystals, the phason degree of freedom and the inherent anharmonic potentials lead to complex dynamics which cannot be described by the usual phonon modes of motion. We have constructed simple one-dimensional model systems, the dynamic Fibonacci chain (DFC) and approximants thereof. They allow us to study the dynamics of periodic and quasiperiodic st

Vinod Prabhakaran, Manoj Prabhakaran

Secure multi-party computation is a central problem in modern cryptography. An important sub-class of this are problems of the following form: Alice and Bob desire to produce sample(s) of a pair of jointly distributed random variables. Each party must learn nothing more about the other party&#39;s output than what its own output reveals. To aid in this, they

A. Niedzwiecki, F. -G. Xie, A. A. Zdziarski

We present preliminary results of our study of the impact of strong gravity effects on properties of the high energy radiation produced in accretion flows around supermassive black holes. We refine a model of the X-ray emission from a hot optically-thin flow by combining a fully general-relativistic (GR) hydrodynamical description of the flow with a fully GR

G Montagna, G Balossini, C Bignamini, C M Carloni Calame

The status and accuracy of the precision Monte Carlo generators used for luminosity measurements at flavour factories is reviewed. It is shown that, thanks to a considerable, long-term effort in tuned comparisons between the predictions of independent programs, as well as in the validation of the generators against the presently available calculations of the

Simone Calogero, J. Mark Heinzle

We show the existence of a rather general class of closed cosmological models of Bianchi type IX that do not exhibit recollapse but expand for all times. This is despite the fact that these models satisfy the strong energy condition by a wide margin.

Oleksii Yu. Sliusarenko, Vsevolod Yu. Gonchar, Aleksei V. Chechkin, Igor M. Sokolov

We investigate the Kramers escape from a potential well of a test particle driven by fractional Gaussian noise with Hurst exponent 0<H<1. From a numerical analysis we demonstrate the exponential distribution of escape times from the well and analyze in detail the dependence of the mean escape time as function of H and the particle diffusivity D. We observe d

I. Pallecchi, M. Codda, E. Galleani d&#39;Agliano, D. Marre&#39;

The observation of metallic behavior at the interface between insulating oxides has triggered worldwide efforts to shed light on the physics of these systems and clarify some still open issues, among which the dimensional character of the conducting system. In order to address this issue, we measure electrical transport (Seebeck effect, Hall effect and condu