May 2006 arXiv papers — page 8

Y. D. Mayya, A. Bressan, L. Carrasco, L. Hernandez

Spectroscopic, photometric and dynamical data of the inner 3 kpc part of the starburst galaxy M82 are analyzed in order to investigate the star formation history of the stellar disk. The long-slit spectra along the major axis are dominated by Balmer absorption lines in the region outside the nuclear starburst all the way up to ~3.5 scalelengths (mu_B=22 mag/

F. Wyrowski, S. Heyminck, R. Guesten, K. M. Menten

A study of 12 ultracompact HII regions was conducted to probe the physical conditions and kinematics in the inner envelopes of the molecular clumps harboring them. The APEX telescope was used to observe the sources in the CO (4-3) and 13CO (8-7) lines. Line intensities were modeled with the RATRAN radiative transfer code using power laws for the density and

F. Wyrowski, K. M. Menten, P. Schilke, S. Thorwirth

We present a submm study of the massive hot core G327.3-0.6 that constrains its physical parameters and environment. The APEX telescope was used to image CO and N2H+ emission, to observe lines from other molecules toward a hot and a cold molecular core, and to measure the continuum flux density of the hot core. In the C18O J=3-2 line, two clumps were found,

A. Weiss, M. Salaris, J. W. Ferguson, D. R. Alexander

We investigate the influence of both a new generation of low-temperature opacities and of various amounts of alpha-element enhancements on stellar evolution models. New stellar models with two different alpha-element mixtures and two sets of appropriate opacity tables are computed and compared. The influence of the different mixtures as well as that of the i

S. Ramstedt, F. L. Schoeier, H. Olofsson, A. A. Lundgren

We have used a detailed non-LTE radiative transfer code to model new APEX CO(J=3-2) data, and existing CO radio line data, on a sample of 40 AGB S-stars. The derived mass-loss-rate distribution has a median value of 2E-7 Msun/yr, and resembles values obtained for similar samples of M-stars and carbon stars. Possibly, there is a scarcity of high-mass-loss-rat

T. V. Nykytyuk, T. V. Mishenina

Recent observations demonstrate that the thin and thick disks of the Galaxy have different chemical abundance trends and evolution timescales. The relative abundances of $α$-elements in the thick Galactic disk are increased relative to the thin disk. Our goal is to investigate the cause of such differences in thick and thin disk abundances. We investigate th

S. Mieske, M. Hilker, L. Infante

The surface brightness fluctuation (SBF) method is a powerful tool to derive distances to galaxies for which single stars cannot be resolved. Up to now, the method has been calibrated mainly at red colours due to the intrinsic faintness of blue early-type galaxies. In this paper we address the I-band calibration of the SBF method at blue colours, the regime

M. Breger, P. Beck, P. Lenz, L. Schmitzberger

CONTEXT. The Lambda Bootis stars are a small spectroscopic subgroup of Population I A-type stars and show significant underabundances of metals. Many are Delta Scuti pulsators. AIMS. HD 210111 was selected for a detailed multisite pulsation study to determine whether its pulsation properties differ from those of normal A stars. METHODS. 262 hours of high-pre

T. Masseron, S. Van Eck, B. Famaey, S. Goriely

With [Fe/H] = -3.5, CS 30322-023 is the most metal-poor star to exhibit a clear s-process signature and the most metal-poor ``lead star&#39;&#39; known. CS 30322-023 is also remarkable in having the lowest surface gravity (log g <= -0.3) among the metal-poor stars studied to date. The available evidence indicates that this star is presently a thermally-pulsi

Andreas Gronlund, Petter Holme, Petter Minnhagen

We investigate a social system of agents faced with a binary choice. We assume there is a correct, or beneficial, outcome of this choice. Furthermore, we assume agents are influenced by others in making their decision, and that the agents can obtain information that may guide them towards making a correct decision. The dynamic model we propose is of nonequil

R. Kanungo, T. K. Alexander, A. N. Andreyev, G. C. Ball

The Doppler-shift attenuation method was applied to measure the lifetime of the 4.03 MeV state in 19Ne. Utilizing a 3He-implanted Au foil as a target, the state was populated using the 20Ne(3He,alpha)19Ne reaction in inverse kinematics at a 20Ne beam energy of 34 MeV. De-excitation gamma rays were detected in coincidence with alpha particles. At the 1 sigma

S. Sykora, A. Huebsch, K. W. Becker

In the spinless Holstein model at half-filling the coupling of electrons to phonons is responsible for a phase transition from a metallic state at small coupling to a Peierls distorted insulated state when the electron-phonon coupling exceeds a critical value. For the adiabatic case of small phonon frequencies, the transition is accompanied by a phonon softe

Bin Xin, Guang&#39;ai Song, Yucai Su

We first prove that, for any generalized Hamiltonian type Lie algebra $L$, the first cohomology group $H^1(L,L \otimes L)$ is trivial. We then show that all Lie bialgebra structures on $L$ are triangular.

Rudnei O Ramos, Marcus B Pinto

We discuss unusual aspects of symmetry that can happen due to entropic effects in the context of multi-scalar field theories at finite temperature. We present their consequences, in special, for the case of nonrelativistic models of hard core spheres. We show that for nonrelativistic models phenomena like inverse symmetry breaking and symmetry non-restoratio

Sukanya Chakrabarti, T. J. Cox, Lars Hernquist, Philip F. Hopkins

We calculate infrared spectral energy distributions (SEDs) from simulations of major galaxy mergers and study the effect of AGN and starburst driven feedback on the evolution of the SED as a function of time. We use a self-consistent three-dimensional radiative equilibrium code to calculate the emergent SEDs and to make images. To facilitate a simple descrip

Oriol Pujolas

The Dvali-Gabadadze-Porrati model introduces a parameter, the cross-over scale $r_c$, setting the scale where higher dimensional effects are important. In order to agree with observations and to explain the current acceleration of the Universe, $r_c$ must be of the order of the present Hubble radius. We discuss a mechanism to generate a large $r_c$, assuming

Oksana Bihun, Carmen Chicone

We consider the problem of distortion minimal morphing of $n$-dimensional compact connected oriented smooth manifolds without boundary embedded in $\R^{n+1}$. Distortion involves bending and stretching. In this paper, minimal distortion (with respect to stretching) is defined as the infinitesimal relative change in volume. The existence of minimal distortion

V. Tapia, M. Ujevic

We show that almost all metric--affine theories of gravity yield Einstein equations with a non--null cosmological constant $Λ$. Under certain circumstances and for any dimension, it is also possible to incorporate a Weyl vector field $W_μ$ and therefore the presence of an anisotropy. The viability of these field equations is discussed in view of recent astro

Ian-Woo Kim, Jihn E. Kim

We study possibilities for lowering the decay constants of superstring axions. In the heterotic Calabi-Yau compactification, a localized model-dependent axion can appear at a nearly collapsing 2-cycle. The effect of flux can be used for generating warp factor suppression of the axion decay constant. We also point out that the hidden sector instanton potentia

Benjamin D. Oppenheimer, Romeel Davé

We investigate models of self-consistent chemical enrichment of the intergalactic medium (IGM) from z=6 to 1.5, based on hydrodynamic simulations of structure formation that incorporate galactic outflows. Our main result is that outflow parameterizations based on momentum-driven winds as seen in local starburst galaxies provide the best agreement with observ

Ulf Leonhardt

As a consequence of the wave nature of light, invisibility devices based on isotropic media cannot be perfect. The principal distortions of invisibility are due to reflections and time delays. Reflections can be made exponentially small for devices that are large in comparison with the wavelength of light. Time delays are unavoidable and will result in wave-

Awatif Hendi, Julian Henn, Ulf Leonhardt

Invisibility devices exploit ambiguities in the inverse scattering problem of light in media. Scattering also serves as an important general tool to infer information about the structure of matter. We elucidate the nature of scattering ambiguities that arise in central potentials. We show that scattering is a tomographic projection: the integrated scattering

Bruce Kleiner, John Lott

These are detailed notes on Perelman&#39;s papers &#34;The entropy formula for the Ricci flow and its geometric applications&#34; and &#34;Ricci flow with surgery on three-manifolds&#34;.

A. Gutierrez-Rodriguez, M. A. Hernandez-Ruiz, B. Jayme-Valdes, M. A. Perez

We obtain bounds on the anomalous magnetic and electric dipole moments of the tau-neutrino through the reaction $e^{+}e^{-}\to ν\bar νγ$ at the $Z_1$-pole in the framework of a Left-Right symmetric model and a class of $E_6$ inspired models with an additional neutral vector boson $Z_θ$. We use the data collected by the L3 Collaboration at LEP. For the parame

T. Csorgo, M. I. Nagy, M. Csanad

A new class of accelerating, exact and explicit solutions of relativistic hydrodynamics is found - more than 50 years after the previous similar result, the Landau-Khalatnikov solution. Surprisingly, the new solutions have a simple form, that generalizes the renowned, but accelerationless, Hwa-Bjorken solution. These new solutions take into account the work

Fabio Siringo, Luca Marotta

The problem of mass generation is addressed by a Gaussian variational method for the minimal left-right symmetric model of electroweak interactions. Without any scalar bidoublet, the Gaussian effective potential is shown to have a minimum for a broken symmetry vacuum with a finite expectation value for both the scalar Higgs doublets. The symmetry is broken b

Yuhong Wang, Kapilanjan Krishan, Michael Dennin

In equilibrium systems, time and ensemble averages of physical quantities are equivalent due to ergodic exploration of phase space. In driven systems, it is unknown if a similar equivalence of time and ensemble averages exists. We explore effective limits of such convergence in a sheared bubble raft using averages of the bubble velocities. In independent exp

Sebastian Casalaina-Martin

This paper extends joint work with R. Friedman to show that the closure of the locus of intermediate Jacobians of smooth cubic threefolds, in the moduli space of principally polarized abelian varieties (ppav&#39;s) of dimension five, is an irreducible component of the locus of ppav&#39;s whose theta divisor has a point of multiplicity three or more. This pap

Nicola Fameli, David A. Balzarini

We have measured the coexistence curve of the binary liquid mixture n-heptane+nitrobenzene near its consolute point using an optical method. In particular, the critical exponent beta describing the coexistence curve was measured for this system. Previous experimental values of beta for n-heptane+nitrobenzene were higher than the typical theoretically calcula

Björn Samuelsson, Joshua E. S. Socolar

We consider propagation models that describe the spreading of an attribute, called &#34;damage&#34;, through the nodes of a random network. In some systems, the average fraction of nodes that remain undamaged vanishes in the large system limit, a phenomenon we refer to as exhaustive percolation. We derive scaling law exponents and exact results for the distr

Carla Petroro, Markus Schmidmeier

Let $R$ be a commutative local uniserial ring of length $n$, $p$ a generator of the maximal ideal, and $k$ the radical factor field. The pairs $(B,A)$ where $B$ is a finitely generated $R$-module and $A\subset B$ a submodule of $B$ such that $p^mA=0$ form the objects in the category $S_m(R)$. We show that in case $m=2$ the categories $S_m(R)$ are in fact qui

J. P. Keating, M. Novaes, S. D. Prado, M. Sieber

We study the resonance (or Gamow) eigenstates of open chaotic systems in the semiclassical limit, distinguishing between left and right eigenstates of the non-unitary quantum propagator, and also between short-lived and long-lived states. The long-lived left (right) eigenstates are shown to concentrate as $\hbar\to 0$ on the forward (backward) trapped set of

Masahiro Sato

A bosonized-field-theory representation of spin operators in the uniform-field-induced Tomonaga-Luttinger-liquid (TLL) phase in spin-1 Haldane chains is formulated by means of the non-Abelian (Tsvelik&#39;s Majorana fermion theory) and the Abelian bosonizations and Furusaki-Zhang technique [Phys. Rev. B {\bf 60}, 1175 (1999)]. It contains massive magnon fiel

Ehud Fuchs, Michael Kroyter

Following Schnabl&#39;s analytic solution to string field theory, we calculate the operators ${\cal L}_0,{\cal L}_0^\dagger$ for a scalar field in the continuous $κ$ basis. We find an explicit and simple expression for them that further simplifies for their sum, which is block diagonal in this basis. We generalize this result for the bosonized ghost sector,

Takashi Hosokawa, Shu-ichiro Inutsuka

We examine the triggering process of molecular cloud formation around diffuse HII regions. We calculate the time evolution of the shell as well as of the HII region in a two-phase neutral medium, solving the UV and FUV radiative transfer, the thermal and chemical processes in the time-dependent hydrodynamics code. In the cold neutral medium, the ambient gas

Masahiro Sato, Masaki Oshikawa

Using the exact results of the O(3) nonlinear sigma model (NLSM) and a few quantitative numerical data for integer-spin antiferromagnetic (AF) chains, we systematically estimate all magnon excitation energies of N-leg integer-spin AF ladders and tubes in the weak-interchain-coupling regime. Our method is based on a first-order perturbation theory for the str

Darren J. Croton, Liang Gao, Simon D. M. White

The clustering of dark halos depends not only on their mass but also on their assembly history, a dependence we term `assembly bias&#39;. Using a galaxy formation model grafted onto the Millennium Simulation of the LCDM cosmogony, we study how assembly bias affects galaxy clustering. We compare the original simulation to `shuffled&#39; versions where the gal

Alexander Yu. Vlasov

It is discussed, why classical simulators of quantum computers escape from some no-go claims like Kochen-Specker, Bell, or recent Conway-Kochen &#34;Free Will&#34; theorems.

M. Boninsegni, N. V. Prokof&#39;ev, B. V. Svistunov

A detailed description is provided of a new Worm Algorithm, enabling the accurate computation of thermodynamic properties of quantum many-body systems in continuous space, at finite temperature. The algorithm is formulated within the general Path Integral Monte Carlo (PIMC) scheme, but also allows one to perform quantum simulations in the grand canonical ens

Pantelis S Apostolopoulos, Jaume Carot

The consistency of the constraint with the evolution equations for spatially inhomogeneous and irrotational silent (SIIS) models of Petrov type I, demands that the former are preserved along the timelike congruence represented by the velocity of the dust fluid, leading to \emph{new} non-trivial constraints. This fact has been used to conjecture that the resu

Jose Javier Garcia MOreta

In this paper we comment the Post inversion formula for Laplace transform, and its possible application to the branch of Analytic Number theory (Arithmetical functions, RH and PNT), involving a condition in the form of iterated limit to calculate the Riemann Hypothesis.

C. W. Groth, B. Michaelis, C. W. J. Beenakker

Destructive interference of single-electron tunneling between three quantum dots can trap an electron in a coherent superposition of charge on two of the dots. Coupling to external charges causes decoherence of this superposition, and in the presence of a large bias voltage each decoherence event transfers a certain number of electrons through the device. We

Mingsheng Ying, Yuan Feng

Loop is a powerful program construct in classical computation, but its power is still not exploited fully in quantum computation. The exploitation of such power definitely requires a deep understanding of the mechanism of quantum loop programs. In this paper, we introduce a general scheme of quantum loops and describe its computational process. The notions o

The HERMES Collaboration, A. Airapetian

The first observation of an azimuthal cross--section asymmetry with respect to the charge of the incoming lepton beam is reported from a study of hard exclusive electroproduction of real photons. The data have been accumulated by the HERMES experiment at DESY, in which the HERA 27.6 GeV electron or positron beam scattered off an unpolarized hydrogen gas targ

S. P. de Alwis

The scales associated with Brown-Teitelboim-Bousso-Polchinski processes of brane nucleation, which result in changes of the flux parameters and the number of D-branes, are discussed in the context of type IIB models with all moduli stabilized. It is argued that such processes are unlikely to be described by effective field theory.

Ugo Bruzzo, Beatriz Graña-Otero

We provide notions of numerical effectiveness and numerical flatness for Higgs vector bundles on compact Kähler manifolds in terms of fibre metrics. We prove several properties of bundles satisfying such conditions and in particular we show that numerically flat Higgs bundles have vanishing Chern classes, and that they admit filtrations whose quotients are s

Quan-Xing Liu, Zhen Jin

We investigate epidemic models with spatial structure based on the cellular automata method. The construction of the cellular automata is from the study by Weimar and Boon about the reaction-diffusion equations [Phys. Rev. E 49, 1749 (1994)]. Our results show that the spatial epidemic models exhibit the spontaneous formation of irregular spiral waves at larg

Dmitrij V. Soroka, Vyacheslav A. Soroka

A semi-simple tensor extension of the Poincar\'e algebra is proposed for the arbitrary dimensions $D$. A supersymmetric also semi-simple generalization of this extension is constructed in the D=4 dimensions. This paper is dedicated to the memory of Anna Yakovlevna Gelyukh.

Massimo Boninsegni, Anatoly Kuklov, Lode Pollet, Nikolay Prokof&#39;ev

The supersolid state of matter, exhibiting non-dissipative flow in solids, has been elusive for thirty five years. The recent discovery of a non-classical moment of inertia in solid 4He by Kim and Chan provided the first experimental evidence, although the interpretation in terms of supersolidity of the ideal crystal phase remains subject to debate. Using qu

Alexandra S. Landsman, Ira B. Schwartz

Coupled distinct arrays of nonlinear oscillators have been shown to have a regime of high frequency, or ultra-harmonic, oscillations that are at multiples of the natural frequency of individual oscillators. The coupled array architectures generate an in-phase high-frequency state by coupling with an array in an anti-phase state. The underlying mechanism for

H. Nikolic

T-duality of string theory suggests nonlocality manifested as the shortest possible distance. As an alternative, we suggest a nonlocal formulation of string theory that breaks T-duality at the fundamental level and does not require the shortest possible distance. Instead, the string has an objective shape in spacetime at all length scales, but different part

Tobias Galla, Michele Leone, Matteo Marsili, Mauro Sellitto

Combinatorial auctions are formulated as frustrated lattice gases on sparse random graphs, allowing the determination of the optimal revenue by methods of statistical physics. Transitions between computationally easy and hard regimes are found and interpreted in terms of the geometric structure of the space of solutions. We introduce an iterative algorithm t

Yonatan Dubi

The problem of the survival of superconductivity in a small super-conducting grain placed in a metal substrate is addressed. For this aim the pair correlations and super-conducting gap around and inside a negative-U impurity in one and two dimensions is calculated, in a discrete tight-binding model and a continuous model. Using the Hartree-Fock-Gorkov mean-f

Seyed Yaser Ayazi, Yasaman Farzan

The possibility of cancelation between different contributions to d_e, d_n and d_{Hg} has been reconsidered with special emphasis on the region that is phenomenologically interesting (intermediate values of \tan βand sub-TeV sfermion masses). It is found that in the range favored by electroweak baryogenesis (\it i.e., |μ|\simeq M_1 or |μ|\simeq M_2), \sin [θ

Gavin P. Salam

Though it is widely taken for granted that it makes sense to separately discuss quark and gluon jets, normal jet algorithms lead to a net parton-level jet flavour that is infrared (IR) unsafe. This writeup illustrates the problem and explains how the kt algorithm can be modified to provide an IR safe parton-level flavour. As well as being of use in theoretic

Vikram B. Mehta, S. Subramanian

We define the local fundamental group scheme, defined by the F-trivial vector bundles, and give necessary and sufficient conditions for it to base change.

Masahiro Kawasaki, Tsutomu Takayama, Masahide Yamaguchi, Jun&#39;ichi Yokoyama

We numerically investigate density perturbations generated in the smooth hybrid new inflation model, a kind of double inflation model that is designed to reproduce the running spectral index suggested by the WMAP results. We confirm that this model provides the running spectral index within 1sigma range of the three year WMAP result. In addition, we find a s

Boris V. Gisin

We consider the general form of the linear transformation for point rotation coordinate frames. The frames have the rotation axis at every point. In the transformation the frequency of one frame relative to another is not equivalent to the reverse frequency. Using symmetry of the direct and reverse transformation as well as symmetry of the frame coordinates

Jia-Zhong Chen

Withdrawn by arXiv administrators because author has forged affiliations and acknowledgments.

A. S. Khvorostukhin, V. V. Skokov, V. D. Toneev, K. Redlich

Based on the quasi-particle description of the QCD medium at finite temperature and density we formulate the phenomenological model for the equation of state that exhibits crossover or the first order deconfinement phase transition. The models are constructed in such a way to be thermodynamically consistent and to satisfy the properties of the ground state n

Christian Bruun Madsen, Lars Bojer Madsen

We present a theoretical model of high-harmonic generation from diatomic molecules. The theory includes effects of alignment as well as nuclear motion and is used to predict results for N$_2$, O$_2$, H$_2$ and D$_2$. The results show that the alignment dependence of high-harmonics is governed by the symmetry of the highest occupied molecular orbital and that

M. R. Hadizadeh, S. Bayegan

The four-body bound state with two-body forces is formulated by the Three-Dimensional approach, which greatly simplifies the numerical calculations of few-body systems without performing the Partial Wave components. We have obtained the Yakubovsky equations directly as three dimensional integral equations.

Fu-Guo Deng, Xi-Han Li, Chun-Yan Li, Ping Zhou

A quantum secure direct communication network scheme is proposed with quantum superdense coding and decoy photons. The servers on a passive optical network prepare and measure the quantum signal, i.e., a sequence of the $d$-dimensional Bell states. After confirming the security of the photons received from the receiver, the sender codes his secret message on

Takashi Nishikawa, Adilson E. Motter

We consider the problem of maximizing the synchronizability of oscillator networks by assigning weights and directions to the links of a given interaction topology. We first extend the well-known master stability formalism to the case of non-diagonalizable networks. We then show that, unless some oscillator is connected to all the others, networks of maximum

C. A. Bertulani

The excitation of soft dipole modes in light nuclei via inelastic electron scattering is investigated. I show that, under the proposed conditions of the forthcoming electron-ion colliders, the scattering cross sections have a direct relation to the scattering by real photons. The advantages of electron scattering over other electromagnetic probes is explored

Ruslan Belikov, N. Jeremy Kasdin, Robert J. Vanderbei

Pupil mapping is a promising and unconventional new method for high contrast imaging being considered for terrestrial exoplanet searches. It employs two (or more) specially designed aspheric mirrors to create a high-contrast amplitude profile across the telescope pupil that does not appreciably attenuate amplitude. As such, it reaps significant benefits in l

Miodrag L. Kulic

The BCS-like pairing in ultracold fermionic atomic ($UCFAG$) gases is studied in the model of &#34;isotopic-spin&#34; pairing proposed in 1991 \cite% {Ku-Hof-SSC}. This model assumes a mismatch ($δ$) in chemical potentials of pairing fermionic atoms. It is shown that a $π$-Josephson junction can be realized in $UCFAG$ systems, where the left and right banks

Xiaofei Huang

This paper presents a global optimization approach to quantum mechanics, which describes the most fundamental dynamics of the universe. It suggests that the wave-like behavior of (sub)atomic particles could be the critical characteristic of a global optimization method deployed by nature so that (sub)atomic systems can find their ground states corresponding

M. Fannes, C. Vandenplas

We characterize the two-site marginals of exchangeable states of a system of quantum spins in terms of a simple positivity condition. This result is used in two applications. We first show that the distance between two-site marginals of permutation invariant states on N spins and exchangeable states is of order 1/N. The second application relates the mean gr

Satoru Odake, Ryu Sasaki

The annihilation-creation operators $a^{(\pm)}$ are defined as the positive/negative frequency parts of the exact Heisenberg operator solution for the `sinusoidal coordinate&#39;. Thus $a^{(\pm)}$ are hermitian conjugate to each other and the relative weights of various terms in them are solely determined by the energy spectrum. This unified method applies t

Miloslav Znojil

PT-symmetric potentials $V({x}) = -{x}^4 +jB {x}^3 + C {x}^2+jD {x} +jF/{x} +G/{x}^2$ are quasi-exactly solvable, i.e., a specific choice of a small $G=G^{(QES)}= integer/4$ is known to lead to wave functions $ψ^{(QES)}(x)$ in closed form at certain charges $F=F^{(QES)}$ and energies $E=E^{(QES)}$. The existence of an alternative, simpler and non-numerical v

Wojciech Tadej, Karol Zyczkowski

Complex Hadamard matrices, consisting of unimodular entries with arbitrary phases, play an important role in the theory of quantum information. We review basic properties of complex Hadamard matrices and present a catalogue of inequivalent cases known for dimension N=2,...,16. In particular, we explicitly write down some families of complex Hadamard matrices

Rodney Van Meter, Kohei M. Itoh, Thaddeus D. Ladd

We show how the execution time of algorithms on quantum computers depends on the architecture of the quantum computer, the choice of algorithms (including subroutines such as arithmetic), and the ``clock speed&#39;&#39; of the quantum computer. The primary architectural features of interest are the ability to execute multiple gates concurrently, the number o

Ambarish Kunwar, Debashish Chowdhury, Andreas Schadschneider, Katsuhiro Nishinari

We investigate a driven diffusive lattice gas model with two oppositely moving species of particles. The model is motivated by bi-directional traffic of ants on a pre-existing trail. A third species, corresponding to pheromones used by the ants for communication, is not conserved and mediates interactions between the particles. Here we study the spatio-tempo

Thomas A. Klar, Alexander V. Kildishev, Vladimir P. Drachev, Vladimir M. Shalaev

The race to engineering metamaterials comprising of a negative refractive index in the optical range has been fueled by the realization of negative index materials for GHz frequencies six years ago. Sheer miniaturization of the GHz resonant structures is one approach. Alternative designs make use of localized plasmon resonant metal nanoparticles or nanoholes

R. Pucci, G. G. N. Angilella

In the centennial of Ettore Majorana&#39;s birth (1906-1938?), we re-examine some aspects of his fundamental scientific production in atomic and molecular physics, including a not well known short communication. There, Majorana critically discusses Fermi&#39;s solution of the celebrated Thomas-Fermi equation for electron screening in atoms and positive ions.

V. G. Anfinogentov, A. E. Hramov

A new version of the virtual cathode oscillator, vircator klystron, is suggested and studied numerically. It essentially includes adjustable external feedback. The non-steady-state nonlinear dynamics of the oscillator is analyzed in relation to the beam current and feedback parameters. Physical processes in the electron beam during transitions between oscill

Alexander Hramov

The electron beam with a virtual cathode (VC) in the drift tube is investigated with the help of a 1.5-dimensional relativistic electromagnetic code. The existence of complex modes, including chaotic modes,is demonstrated. The dynamic nature of chaos in the considered system is revealed. Physical processes in the flow are investigated, and it is found that t

Alexander Hramov

The results of numerical modeling of oscillations in a system of two coupled oscillators operatingon the basis of a virtual cathode with controlled external feedback are presented. It is shown that thereexist the modes with generation of chaotic signals and synchronization modes with high signal-to-noise ratio.The effect of parameters of the electron beam an

Alexander Hramov

The effect of external feedback on the oscillation characteristics of a device with the virtual cathode is investigated by the method of numerical modeling. A strong influence of the feedback phase delay onthe frequency and power level of signals generated in the system is demonstrated.

Chang-Yong Lee

In this paper, we empirically investigate correlations among four centrality measures, originated from the social science, of various complex networks. For each network, we compute the centrality measures, from which the partial correlation as well as the correlation coefficient among measures is estimated. We uncover that the degree and the betweenness cent

Peter Leifer

An attempt to build quantum theory of field (extended) objects without a priori space-time geometry has been represented. Space-time coordinates are replaced by the intrinsic coordinates in the tangent fibre bundle over complex projective Hilbert state space $CP(N-1)$. The fate of a quantum system modeled by the generalized coherent states is rooted in this

A. Al-Sayed, A. Y. Abul-Magd

The nearest neighbor spacing distribution of levels of deformed even-even nuclei classified according to their quadrupole deformation parameter is investigated. The results suggest that the oblate deformed nuclei have more regular spectra than prolate ones.

PHENIX Collaboration, S. S. Adler

Emission source functions are extracted from correlation functions constructed from charged pions produced at mid-rapidity in Au+Au collisions at sqrt(s_NN)=200 GeV. The source parameters extracted from these functions at low k_T, give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kin

A. Mischke

The STAR experiment at the Relativistic Heavy-Ion Collider has performed measurements of high transverse momentum particle production in ultra-relativistic heavy-ion collisions. High-pT hadrons are generated from hard parton scatterings early in the collision. The outgoing partons probe the surrounded hot and dense matter through interactions. Recent results

H. Susanto, P. G. Kevrekidis, R. Carretero-Gonzalez, Boris A. Malomed

We study the mobility of solitons in second-harmonic-generating lattices. Contrary to what is known for their cubic counterparts, discrete quadratic solitons are mobile not only in the one-dimensional (1D) setting, but also in two dimensions (2D). We identify parametric regions where an initial kick applied to a soliton leads to three possible outcomes, name

Herbert Spohn

In my book ``Large Scale Dynamics of Interacting Particles&#39;&#39; [S] I refer to an unpublished note from early 1985 on the BBGKY hierarchy for hard spheres. My main point there was to provide a direct probabilistic proof for the time-integrated version of the hierarchy. Over recent years there has been repeated interest in this derivation, which encourag

Elena Kartashova

Traditionally resonant interactions among short waves, with large real wave-numbers, were described statistically and only a small domain in spectral space with integer wave-numbers, discrete resonances, had to be studied separately in resonators. Numerical simulations of the last few years showed unambiguously the existence of some discrete effects in the s

Pablo A. Ferrari, Nevena Maric

We consider an irreducible pure jump Markov process with rates Q=(q(x,y)) on Λ\cup\{0\} with Λcountable and 0 an absorbing state. A quasi-stationary distribution (qsd) is a probability measure νon Λthat satisfies: starting with ν, the conditional distribution at time t, given that at time t the process has not been absorbed, is still ν. That is, ν(x) = νP_t(

David A. Madore

This note (which makes no claim to novelty) presents a proof of the separable rational connectedness of smooth cubic hypersurfaces, in any characteristic, by showing how to explicitly construct very free curves (of degree 3) on them. ----- Cette note (qui ne prétend pas à l&#39;originalité) démontre la séparable rationnelle connexité des hypersurfaces cubiqu

Pantelis A. Damianou, Herve Sabourin, Pol Vanhaecke

We study the transverse Poisson structure to adjoint orbits in a complex semi-simple Lie algebra. The problem is first reduced to the case of nilpotent orbits. We prove then that in suitably chosen quasi-homogeneous coordinates the quasi-degree of the transverse Poisson structure is -2. In the particular case of {\emph subregular} nilpotent orbits we show th

F. Baudoin, M. Hairer

It is shown that the law of an SDE driven by fractional Brownian motion with Hurst parameter greater than 1/2 has a smooth density with respect to Lebesgue measure, provided that the driving vector fields satisfy Hörmander&#39;s condition. The main new ingredient of the proof is an extension of Norris&#39; lemma to this situation.

S. V. Lototsky, B. L. Rozovskii

A new method is described for constructing a generalized solution of a stochastic evolution equation. Existence, uniqueness, regularity and a probabilistic representation of this Wiener Chaos solution are established for a large class of equations. As an application of the general theory, new results are obtained for several types of the passive scalar equat

Mark Conger, D. Viswanath

By a well-known result of Bayer and Diaconis, the maximum entropy model of the common riffle shuffle implies that the number of riffle shuffles necessary to mix a standard deck of 52 cards is either 7 or 11--with the former number applying when the metric used to define mixing is the total variation distance and the latter when it is the separation distance.

Ernesto Lupercio, Bernardo Uribe

In this expository paper written for physicists and geometers we introduce the notions of TQFT and of orbifold. Then we survey the construction of TQFT&#39;s originating from orbifolds such as Chen-Ruan theory and Orbifold String Topology.

Jean-Paul Blaizot, Ramon Mendez-Galain, Nicolas Wschebor

We present the first numerical application of a method that we have recently proposed to solve the Non Perturbative Renormalization Group equations and obtain the n-point functions for arbitrary external momenta. This method leads to flow equations for the n-point functions which are also differential equations with respect to a constant background field. Th

Michael A. Soloviev

We analyze functional analytic aspects of axiomatic formulations of nonlocal and noncommutative quantum field theories. In particular, we completely clarify the relation between the asymptotic commutativity condition, which ensures the CPT symmetry and the standard spin-statistics relation for nonlocal fields, and the regularity properties of the retarded Gr

B. A. Robson, S. H. Sutanto

The recently proposed eight-component relativistic wave equation is applied to the scattering of a photon from a free electron (Compton scattering). It is found that in spite of the considerable difference in the structure of this equation and that of Dirac the cross section is given by the Klein-Nishina formula.

D. V. Gioutsos

In this talk, gauge coupling evolution is analyzed in D-brane inspired models with two Higgs doublets and a U(3)xU(2)xU(1)^N gauge symmetry. In particular, we focus on D-brane configurations with two or three abelian factors. We find that the correct hypercharge assignment of the Standard Model particles is reproduced for six viable models distinguished by d

Adam Bzdak

We briefly present the QCD based calculation of exclusive J/psi production via pomeron-odderon fusion in proton-antiproton collisions. For the Tevatron energy the differential cross section dsigma/dy(y=0) is estimated to be around 1 nb.