October 2008 arXiv papers — page 45

Justine Serrano

Some recent Babar results on semileptonic decays are presented. They focus on the determination of the CKM matrix elements |V_{ub}| and |V_{cb}| in inclusive and exclusive b --> u l nu and b--> c l nu decays, and on form factors measurement in exclusive c--> s l nu decays.

Chris Quigg

I offer a brief summary, with commentary, of theoretical contributions to Moriond QCD 2008.

Sylvain Joubaud, Guillaume Huillard, Artyom Petrosyan, Sergio Ciliberto

The orientation fluctuations of the director of a liquid crystal are measured, by a sensitive polarization interferometer, close to the Fréedericksz transition, which is a second order transition driven by an electric field. Using mean field theory, we define the work injected into the system by a change of the electric field and we calibrate it using Fluctu

M. Trezza, S. L. Prischepa, C. Cirillo, R. Fittipaldi

Porous silicon, obtained by electrochemical etching, has been used as a substrate for the growth of nanoperforated Nb thin films. The films, deposited by UHV magnetron sputtering on the porous Si substrates, inherited their structure made of holes of 5 or 10 nm diameter and of 10 to 40 nm spacing, which provide an artificial pinning structure. The supercondu

G. D. Samolyuk, V. P. Antropov

The density functional non-interacting susceptibility has been analyzed in different phases of CaFe2As2 and compared with similar data for pure d-metals. The conditions for the "no local moment" itinerant state with large frustrations are found for the "collapsed" phase (corresponding to superconducting phase). This itineracy determines the i

D. B. Jess, M. Mathioudakis, P. J. Crockett, F. P. Keenan

High-cadence, multiwavelength optical observations of a solar active region (NOAA 10969), obtained with the Swedish Solar Telescope, are presented. Difference imaging of white light continuum data reveals a white light brightening, 2 min in duration, linked to a co-temporal and co-spatial C2.0 flare event. The flare kernel observed in the white light images

Michele Maltoni

In this talk we will discuss the physics reach of the atmospheric neutrino data collected by a future megaton-class neutrino detector. First we will discuss the potentialities of atmospheric neutrinos on general basis, presenting our results in the form of neutrino oscillograms of the Earth: contour plots in the neutrino energy--nadir angle plane. In this co

Remo Ruffini, She-Sheng Xue

We first recall the concept of Dyadosphere (electron-positron-photon plasma around a formed black holes) and its motivation, and recall on (i) the Dirac process: annihilation of electron-positron pairs to photons; (ii) the Breit-Wheeler process: production of electron-positron pairs by photons with the energy larger than electron-positron mass threshold; the

Baogang Xu

Borodin et al figured out a gap of the paper published at J. Combinatorial Theory Ser. B (Vol.96 (2006) 958--963), and gave a new proof with the similar technique. The purpose of this note is to fix the gap by slightly revising the definition of special faces, and adding a few lines of explanation in the proofs (new added text are all in black font).

F. Vazquez, C. Lopez

We propose a general approach to study spin models with two symmetric absorbing states. Starting from the microscopic dynamics on a square lattice, we derive a Langevin equation for the time evolution of the magnetization field, that successfully explains coarsening properties of a wide range of nonlinear voter models and systems with intermediate states. We

Francesca Da Lio, Olivier Ley

Unbounded stochastic control problems may lead to Hamilton-Jacobi-Bellman equations whose Hamiltonians are not always defined, especially when the diffusion term is unbounded with respect to the control. We obtain existence and uniqueness of viscosity solutions growing at most like $o(1+|x|^p)$ at infinity for such HJB equations and more generally for degene

M. Revnivtsev, A. Kniazev, S. Sazonov, R. Burenin

We have optically identified a recently discovered INTEGRAL source, IGR J08390--4833, with a cataclysmic variable, i.e. an accreting white dwarf in a binary system. The spectrum exhibits a rising blue continuum together with Balmer and HeII emission lines. Analysis of the light curve of the source shows clear presence of intrinsic variability on a time scale

Libor Vesely, Ludek Zajicek

We show how our recent results on compositions of d.c. functions (and mappings) imply positive results on extensions of d.c. functions (and mappings). Examples answering two natural relevant questions are presented. Two further theorems, concerning extendability of continuous convex functions from a closed subspace of a normed linear space, complement recent

D. Valenti, G. Augello, B. Spagnolo

We analyze the dynamics of the FitzHugh-Nagumo (FHN) model in the presence of colored noise and a periodic signal. Two cases are considered: (i) the dynamics of the membrane potential is affected by the noise, (ii) the slow dynamics of the recovery variable is subject to noise. We investigate the role of the colored noise on the neuron dynamics by the mean r

Edmundo M. Monte

The braneworlds models were inspired partly by Kaluza-Klein's theory, where both the gravitational and the gauge fields are obtained from the geometry of a higher dimensional space. The positive aspects of these models consist in perspectives of modifications it could bring in to particle physics, such as: unification in a TeV scale, quantum gravity in t

Omar Mehanna, Ahmed Sultan, Hesham El Gamal

We consider the design of cognitive Medium Access Control (MAC) protocols enabling an unlicensed (secondary) transmitter-receiver pair to communicate over the idle periods of a set of licensed channels, i.e., the primary network. The objective is to maximize data throughput while maintaining the synchronization between secondary users and avoiding interferen

Attila Fekete, Gábor Vattay

In this paper we present an analytic study of sampled networks in the case of some important shortest-path sampling models. We present analytic formulas for the probability of edge discovery in the case of an evolving and a static network model. We also show that the number of discovered edges in a finite network scales much slower than predicted by earlier

Kourosh Nozari, M. R. Setare, Tahereh Azizi, Noushin Behrouz

We study dynamics of equation of state parameter for a non-minimally coupled quintom dark energy component on the warped DGP brane. We investigate crossing of the cosmological constant line in this scenario. This crossing occurs in both DGP$^{\pm}$ branches of the model.

Matthew L. Wallace, Vincent Larivière, Yves Gingras

Changes in citation distributions over 100 years can reveal much about the evolution of the scientific communities or disciplines. The prevalence of uncited papers or of highly-cited papers, with respect to the bulk of publications, provides important clues as to the dynamics of scientific research. Using 25 million papers and 600 million references from the

Bikash Kumar Dey, Sidharth Jaggi, Michael Langberg

We provide a novel achievability proof of the Slepian-Wolf theorem for i.i.d. sources over finite alphabets. We demonstrate that random codes that are linear over the real field achieve the classical Slepian-Wolf rate-region. For finite alphabets we show that typicality decoding is equivalent to solving an integer program. Minimum entropy decoding is also sh

F. Grenier, A. Chbihi, R. Roy, G. Verde

Unstable 10C nuclei are produced as quasi-projectiles in 12C+24Mg collisions at E/A = 53 and 95 MeV. The decay of their short-lived states is studied with the INDRA multidetector array via multi-particle correlation functions. The obtained results show that heavy-ion collisions can be used as a tool to access spectroscopic information of unbound states in ex

Lei Fang, Huan Yang, Peng Cheng, Xiyu Zhu

We report the synthesizing and characterization of the hole doped Ni-based superconductor ($La_{1-x}Sr_{x})NiAsO$. By substituting La with Sr, the superconducting transition temperature $T_c$ is increased from 2.4 K of the parent phase $LaNiAsO$ to 3.7 K at the doping levels x= 0.1 - 0.2. The curve $T_c$ versus hole concentration shows a symmetric behavior a

D. Dornic D, S. Basa, J. Brunner, J. Busto

The ANTARES telescope has the opportunity to detect transient neutrino sources, such as gamma-ray bursts (GRBs), core-collapse supernovae (SNe), flares of active galactic nuclei (AGNs)... To enhance the sensitivity to these sources, we are developing a new detection method based on the observation of neutrino bursts followed by an optical detection. The ANTA

A. L. Wilmot-Smith, G. Hornig, D. I. Pontin

The braiding of the solar coronal magnetic field via photospheric motions - with subsequent relaxation and magnetic reconnection -- is one of the most widely debated ideas of solar physics. We readdress the theory in the light of developments in three-dimensional magnetic reconnection theory. It is known that the integrated parallel electric field along fiel

S. Montangero, M. Rizzi, V. Giovannetti, R. Fazio

An algorithm for optimizing the MERA tensor network in an infinite system is presented. Using this technique we compute the critical exponents of Ising and XXZ model.

J. Liu, T. Last, E. J. Koop, S. Denega

We present a numerical study of dephasing of electron spin ensembles in a diffusive quasi-one-dimensional GaAs wire due to the D'yakonov-Perel' spin-dephasing mechanism. For widths of the wire below the spin precession length and for equal strength of Rashba and linear Dresselhaus spin-orbit fields a strong suppression of spin-dephasing is found. Thi

R. Carminati, M. Donaire, J. J. Saenz

We establish a fundamental relationship between the averaged density of states and the extinction mean free path of wave propagating in random media. From the principle of causality and the Kramers-Kronig relations, we show that both quantities are connected by dispersion relations and are constrained by a frequency sum rule. The results are valid under very

A. Foussats, A. Greco, M. Bejas

One-electron self-energy in the $t$-$J$ model was computed using a recently developed large-$N$ method based on the path integral representation for Hubbard operators. One of the main features of the self-energy is its strong asymmetry with respect to the Fermi level, showing the spectra mostly concentrated at high negative energy. This asymmetry is responsi

R. K. S. Yadav, Brijesh Kumar, A. Subramaniam, Ram Sagar

We present UBVRI CCD photometry in the region of the open clusters NGC 637 and NGC 957. The radii are found to be 4.2 arcmin and 4.3 arcmin. Their reddenings E(B-V) are 0.64+/-0.05 mag and 0.71+/-0.05 mag and their distances, from main sequence fitting are 2.5+/-0.2 kpc and 2.2+/-0.2 kpc. Comparison with Z=0.02 isochrones leads to an age of 10+/-5 Myr for bo

Samy Tindel, Jérémie Unterberger

In this paper, we consider a complex-valued d-dimensional fractional Brownian motion defined on the closure of the complex upper half-plane, called analytic fractional Brownian motion. This process has been introduced by the second author of the article, and both its real and imaginary parts, restricted on the real axis, are usual fractional Brownian motions

Georg G. Raffelt

We identify a generic new form of collective flavor oscillations in dense neutrino gases that amounts to a self-induced parametric resonance. It occurs in a homogeneous and isotropic ensemble when a range of neutrino modes is prepared in a different flavor than the neighboring modes with lower and higher energies. The flavor content of the intermediate spect

Luca Leuzzi

In this paper we present a short survey on the concept of effective temperature, on its onset as a glass former vitrifies, on the various definitions in literature and their limits of applicability. An exactly solvable model glass is employed to compare effective temperatures among them and to set a criterion for the occurrence of a universal extra temperatu

Ji-Haeng Huh

We update cosmological bound on axion model. The contribution from the anharmonic effect and the newly introduced initial overshoot correction are considered. We present an explicit formula for the axion relic density in terms of the QCD scale Lambda_{QCD}, the current quark masses m_q's and the Peccei-Quinn scale F_a, including firstly introduced 1.85 f

Gerhard Baur

Heavy ions at high velocities provide very strong electromagnetic fields for a very short time. The main characteristics of ultraperipheral relativistic heavy ion collisions are reviewed, characteristic parameters are identified. The main interest in ultraperipheral heavy ion collisions at relativistic ion colliders like the LHC is the interactions of very h

I. Boyko

The so-called 'LSND anomaly', a 3.8 sigma excess of anti-nu_e events interpreted as originating from anti-nu_mu -> anti-nu_e oscillation, gave rise to many theoretical speculations. The MiniBooNE Collaboration reported inconsistency of this interpretation with the findings from their search for nu_mu -> nu_e oscillations. Yet the origin of the LSND a

Wolfram Schmidt, Christoph Federrath, Ralf Klessen

The statistical properties of turbulence are considered to be universal at sufficiently small length scales, i. e., independent of boundary conditions and large-scale forces acting on the fluid. Analyzing data from numerical simulations of supersonic turbulent flow driven by external forcing, we demonstrate that this is not generally true for the two-point v

I. Boyko

Hadron generation models are indispensable for the simulation and calibration of particle physics detectors. The models used by the Geant4 simulation tool kit are compared with inclusive spectra of secondary protons and pions from the interactions with beryllium nuclei of +8.9 GeV/c protons and pions, and of -8.0 GeV/c pions. We report on significant disagre

I. Boyko

Precise measurements of neutrino oscillation parameters and of neutrino-nucleon cross-sections require a good understanding of neutrino beams: flux as a function of energy, transverse beam profile, and flavour composition. For this, hadron production spectra in proton-nucleus collisions are essential. We report on double-differential inclusive large-angle cr

Stephane Basa, Damien Dornic, Gabrielle Lelaizant, Bruce Gendre

GRBs are the most energetic events in the Universe, associated with the death of massive stars (core-collapse supernovae) or the merging of neutron stars or black holes. Discovered in the early 1970s, their cosmological origin was demonstrated only in 1997, when the first distance was measured. Theoretical models predict that the very energetic processes at

E. I. Vorobyov

(Abridged). Motivated by a growing concern that masses of circumstellar disks may have been systematically underestimated by conventional observational methods, we present a numerical hydrodynamics study of time-averaged disk masses (<M_d>) around low-mass Class 0, Class I, and Class II objects. Mean disk masses (\overline{M}_d}) are then calculated by weigh

Marcin Sabok

The dichotomy discovered by Solecki in \cite{Sol} states that any Baire class 1 function is either $σ$-continuous or &#34;includes&#34; the Pawlikowski function $P$. The aim of this paper is to give an argument which is simpler than the original proof of Solecki and gives a stronger statement: a dichotomy for all Borel functions.

Bin Zhou, Shu-Min Li

We study the elastic scattering of atomic argon by a electron in the presence of a bichromatic laser field. The numerical calculation is done in the first Born approximation (FBA) for a simple screening electric potential. With the help of numerical results we explore the dependence of the differential cross sections (DCS) on the relative phase between the t

Federica Pezzotti, Mario Pulvirenti

We consider a quantum system constituted by $N$ identical particles interacting by means of a mean-field Hamiltonian. It is well known that, in the limit $N\to\infty$, the one-particle state obeys to the Hartree equation. Moreover, propagation of chaos holds. In this paper, we take care of the $\hbar$ dependence by considering the semiclassical expansion of

S. Ober-Bloebaum, O. Junge, J. E. Marsden

The optimal control of a mechanical system is of crucial importance in many realms. Typical examples are the determination of a time-minimal path in vehicle dynamics, a minimal energy trajectory in space mission design, or optimal motion sequences in robotics and biomechanics. In most cases, some sort of discretization of the original, infinite-dimensional o

M. P. E. Schurch, M. J. Coe, J. L. Galache, R. H. D. Corbet

On 30th August 2006 SXP18.3 a high mass X-ray binary (HMXB) in the Small Magellanic Cloud (SMC) with an 18.3s pulse period was observed by Rossi X-ray Timing Explorer (RXTE). The source was seen continuously for the following 36 weeks. This is the longest Type II outburst ever seen from a HMXB in the SMC. During the outburst SXP18.3 was located from serendip

Subir K. Das, Jürgen Horbach, Kurt Binder

A description of phase separation kinetics for solid binary (A,B) mixtures in thin film geometry based on the Kawasaki spin-exchange kinetic Ising model is presented in a discrete lattice molecular field formulation. It is shown that the model describes the interplay of wetting layer formation and lateral phase separation, which leads to a characteristic dom

M. Kawashima, M. Oka

In this paper, we compute Alexander polynomials of a torus curve C of type (2, 5), C : f(x, y) = f_2(x, y)^5 + f_5(x, y)^2 = 0, under the assumption that the origin O is the unique inner singularity and f2 = 0 is an irreducible conic. We show that the Alexander polynomial remains the same with that of a generic torus curve as long as C is irreducible.

Marie Doumic Jauffret, Benoît Perthame, Jorge P. Zubelli

We consider a size-structured model for cell division and address the question of determining the division (birth) rate from the measured stable size distribution of the population. We propose a new regularization technique based on a filtering approach. We prove convergence of the algorithm and validate the theoretical results by implementing numerical simu

J. C. Gonzalez-Davila, Francisco Martin Cabrera

We go further on the study of harmonicity for almost contact metric structures already initiated by Vergara-Diaz and Wood. By using the intrinsic torsion, we characterise harmonic almost contact metric structures in several equivalent ways and show conditions relating harmonicity and classes of almost contact metric structures. Additionally, we study the har

J. L. Cieslinski, B. Ratkiewicz

We compare the performance of several discretizations of the simple pendulum equation in a series of numerical experiments. The stress is put on the long-time behaviour. We choose for the comparison numerical schemes which preserve the qualitative features of solutions (like periodicity). All these schemes are either symplectic maps or integrable (preserving

K. Igawa, H. Okada, H. Takahashi, S. Matsuishi

Electrical resistivity under high pressure have been measured on nominally pure SrFe2As2 up to 14 GPa. The resistivity drop appeared with increasing pressure, and we clearly observed zero resistivity. The maximum of superconducting transition temperature (Tc) is 38 K. The value is corresponding to the one of optimally doping AFe2As2 (A=Sr, Ba) system with K+

Marc Barthelemy, Alessandro Flammini

We study the influence that population density and the road network have on each others&#39; growth and evolution. We use a simple model of formation and evolution of city roads which reproduces the most important empirical features of street networks in cities. Within this framework, we explicitely introduce the topology of the road network and analyze how

U. Munari, A. Siviero, P. Ochner, S. Dallaporta

We obtained BVIc photometry of IRC-10443 on 85 different nights distributed over two years, and in addition low resolution absolute spectro- photometry and high resolution Echelle spectroscopy. Our data show that IRC-10443, which was never studied before in any detail, is a SRa variable, characterized by Delta(B)=1.27, Delta(V)=1.14 and Delta(I)=0.70 mag amp

Makoto Kishimoto, Robert Antonucci, Omer Blaes, Andy Lawrence

A crucial difficulty in understanding the nature of the putative accretion disk in AGNs is that some of its key intrinsic spectral signatures cannot be observed directly. The strong emissions from the broad-line region (BLR) and the obscuring torus, which are generally yet to be spatially resolved, essentially &#39;bury&#39; such signatures. Here we argue th

Edoardo Ballico, Maria Chiara Brambilla

We study the postulation of a general union $Y$ of double, triple, and quartuple points of $\mathbb{P}^3$. We prove that $Y$ has the expected postulation in degree $d\ge 41$, using the Horace differential lemma. We also discuss the cases of low degree with the aid of computer algebra.

A. A. Dubkov, B. Spagnolo

The transient dynamics of the Verhulst model perturbed by arbitrary non-Gaussian white noise is investigated. Based on the infinitely divisible distribution of the Levy process we study the nonlinear relaxation of the population density for three cases of white non-Gaussian noise: (i) shot noise, (ii) noise with a probability density of increments expressed

K. S. Kim, Myung-Ki Cheoun

Neutrino (antineutrino) scattering off $^{12}$C is one of various important key reactions for $ν$-process in the nucleosysnthesis of light nuclei. Most of neutrino-nucleus scattering are considered through indirect processes within the energy range from a few to tens of MeV. Target nuclei are excited by incident neutrino (antineutrino) through various transi

Ali Khaleghi, Ghaïs El Zein, Ijaz Haider Naqvi

Using time domain measurements, we assess the feasibility of time-reversal technique in ultra-wideband (UWB) communication. A typical indoor propagation channel is selected for the exploration. The channel response between receive and transmit antenna pairs is measured using time domain equipments which include an arbitrary wave generator (AWG) and a digital

A. Majumder

The modification of hard jets in dense matter has so far been described by four different formalisms based on perturbative QCD (pQCD). In these proceedings, we compare the various approximations made in these different schemes, especially those regarding the structure of the medium through which jets propagate. Following this, we highlight some of the major

S. L. Druta

We study the conditions under which an almost Hermitian structure $(G,J)$ of general natural lift type on the cotangent bundle $T^*M$ of a Riemannian manifold $(M,g)$ is K\&#34; ahlerian. First, we obtain the algebraic conditions under which the manifold $(T^*M,G,J)$ is almost Hermitian. Next we get the integrability conditions for the almost complex structu

Christian Wegner

We state and prove a condition under which the strong Atiyah Conjecture carries over to subgroups. Moreover, we show that if a group satisfies the (strong) Atiyah Conjecture then any quotient with finite kernel does.

J. Prakash, S. J. Singh, S. Patnaik, A. K. Ganguli

Pure phases of a new oxyarsenide superconductor of the nominal composition CeOFe0.9Co0.1As was successfully synthesized by solid state reaction in sealed silica ampoules at 1180 C. It crystallizes in the layered tetragonal ZrCuSiAs type structure (sp gp P4/nmm) with lattice parameter of a = 3.9918(5) angstrom and c = 8.603(1) angstrom. A sharp superconductin

S. Druta

We study some properties of the tangent bundles with metrics of general natural lifted type. We consider a Riemannian manifold $(M,g)$ and we find the conditions under which the Riemannian manifold $(TM,G)$, where $TM$ is the tangent bundle of $M$ and $G$ is the general natural lifted metric of $g$, has constant sectional curvature.

G. Belanger, E. Nezri, A. Pukhov

We examine the predictions for both the spin dependent and spin independent direct detection rates in a variety of new particle physics models with dark matter candidates. We show that a determination of both spin independent and spin dependent amplitudes on protons and neutrons can in principle discriminate different candidates of dark matter up to a few am

J. Noaki, S. Aoki, T. W. Chiu, H. Fukaya

We report on a numerical simulation with 2+1 dynamical flavors of overlap fermions. We calculate pseudo-scalar masses and decay constants on a $16^3\times 48 \times (0.11 {\rm fm})^4$ lattice at five different up and down quark masses and two strange quark masses. The lightest pion mass corresponds to $\approx 310$ MeV. We also study the validity of the chir

Shigeyuki Takagi, Jun-ichi Hoshino, Hidekazu Tomono, Kazuo Tsumuraya

We investigate the electron transfer from a dissociatively adsorbed H2 molecule to a Au(111) surface using the first-principles methods. A fractional electron transfers from a molecule to a substrate, and potential energy increases during the process. The initial energy increase coincides with that of the isolated, separated, and positively charged H2 molecu

Nissim Kanekar

Comparisons between the redshifts of spectral lines from cosmologically-distant galaxies can be used to probe temporal changes in low-energy fundamental constants like the fine structure constant and the proton-electron mass ratio. In this article, I review the results from, and the advantages and disadvantages of, the best techniques using this approach, be

Jure Leskovec, Kevin J. Lang, Anirban Dasgupta, Michael W. Mahoney

A large body of work has been devoted to defining and identifying clusters or communities in social and information networks. We explore from a novel perspective several questions related to identifying meaningful communities in large social and information networks, and we come to several striking conclusions. We employ approximation algorithms for the grap

David Victor Feldman

For $0<c<1$ the number of divisors of $q$ below $q^{c}$ averages, over $q\le B$, to $c\log B+(γ-c)+O(B^{-\min(c,1-c)})$, where $γ$ denotes the Euler--Mascheroni constant. Consequently the number of divisors in a window $(q^{a},q^{b})$ averages to $(b-a)(\log B-1)+o(1)$: the constant $γ$ cancels, and the average counts for two windows stand asymptotically in

Henry H. Hsieh, David Jewitt, Masateru Ishiguro

The main-belt comets occupy dynamically asteroidal orbits in the main asteroid belt. Here we present physical observations of the second-known member of this population, P/2005 U1 (Read), which showed vigorous cometary activity from 2005 October 24 to 2005 December 27. Monte Carlo numerical simulations of P/Read&#39;s dust emission indicate that the coma and

Michael Uhlmann

Quantum fluctuations in time-dependent, harmonically-trapped Bose-Einstein condensates are studied within Bogoliubov theory. An eigenmode expansion of the linear field operators permits the diagonalization of the Bogoliubov-de Gennes equation for a stationary condensate. When trap frequency or interaction strength are varied, the inhomogeneity of the backgro

Guoce Xin, Terence Y. J. Zhang

Schutzenberger&#39;s theorem for the ordinary RSK correspondence naturally extends to Chen et. al&#39;s correspondence for matchings and partitions. Thus the counting of bilaterally symmetric $k$-noncrossing partitions naturally arises as an analogue for involutions. In obtaining the analogous result for 3-noncrossing partitions, we use a different technique

Jing Zhang

The form of a local Clifford (LC, also called local Gaussian (LG)) operation for the continuous-variable (CV) weighted graph states is presented in this paper, which is the counterpart of the LC operation of local complementation for qubit graph states. The novel property of the CV weighted graph states is shown, which can be expressed by the stabilizer form

Myung-Hwan Kim, Poo-Sung Park

A positive definite Hermitian lattice is said to be 2-universal if it represents all positive definite binary Hermitian lattices. We find all 2-universal ternary and quaternary Hermitian lattices over imaginary quadratic number fields.

De-Fu Bu, Feng Yuan, Fu-Guo Xie

Observations and numerical magnetohydrodynamic (MHD) simulations indicate the existence of outflows and ordered large-scale magnetic fields in the inner region of hot accretion flows. In this paper we present the self-similar solutions for advection-dominated accretion flows (ADAFs) with outflows and ordered magnetic fields. Stimulated by numerical simulatio

R. Prozorov, N. Ni, M. A. Tanatar, V. G. Kogan

Detailed measurements of the global and local electromagnetic properties of Ba(Fe$_{0.93}$Co$_{0.07}$)$_{2}$As$_{2}$ single crystals are reported. Analysis of the irreversible magnetic response provides strong evidence for similar vortex physics in this Fe-based pnictide superconductor to the high-$T_{c}$ cuprates, such as Y-Ba-Cu-O or Nd-Ce-Cu-O. In particu

Karina Garay-Palmett, Alfred B. U&#39;Ren, Raúl Rangel-Rojo, Rodger Evans

We present a study of the spectral properties of photon pairs generated through the process of spontaneous four wave mixing (SFWM) in single mode fiber. Our analysis assumes narrowband pumps, which are allowed to be frequency-degenerate or non-degenerate. Based on this analysis, we derive conditions on the pump frequencies and on the fiber dispersion paramet

Karina Garay-Palmett, Raúl Rangel-Rojo, Alfred B. U&#39;Ren

We study photon pair generation through scalar spontaneous four-wave mixing in single-mode fibre and for frequency-degenerate pumps; we concentrate on source geometries which fulfil full group velocity matching (GVM), i.e. where the pump, signal and idler propagate at identical group velocities. We discuss two experimental techniques which permit the attainm

Edgar Carrera

We present a search for large extra dimensions in the single photon plus missing transverse energy channel (Kaluza-Klein graviton production) performed using 2.7 fb-1 of data collected by the D0 experiment at the Fermilab Tevatron collider. At 95% C.L., we set limits on the fundamental Planck scale M_{D} from 970 GeV to 816 GeV for two to eight extra dimensi

N. Lugaz, I. I. Roussev, I. V. Sokolov

We discuss how some coronal mass ejections (CMEs) originating from the western limb of the Sun are associated with space weather effects such as solar energetic particles (SEPs), shock or geo-effective ejecta at Earth. We focus on the August 24, 2002 coronal mass ejection, a fast (~ 2000 km/s) eruption originating from W81. Using a three-dimensional magneto-

Zongming Ma

Let A be a p-variate real Wishart matrix on n degrees of freedom with identity covariance. The distribution of the largest eigenvalue in A has important applications in multivariate statistics. Consider the asymptotics when p grows in proportion to n, it is known from Johnstone (2001) that after centering and scaling, these distributions approach the orthogo

Akira R. Kinjo, Haruki Nakamura

Comprehensive knowledge of protein-ligand interactions should provide a useful basis for annotating protein functions, studying protein evolution, engineering enzymatic activity, and designing drugs. To investigate the diversity and universality of ligand binding sites in protein structures, we conducted the all-against-all atomic-level structural comparison

Abel Camacho, Abel Camacho-Galvan

The limitations and possibilities that the concept of quantum interference offers as a tool for testing fundamental physics are explored here. The use of neutron interference as an instrument to confront against measurement readouts some of the principles behind metric theories of gravity will be analyzed, as well as some discrepancies between theory and exp

Steve Blanchet, Pavel Fileviez Perez

The link between low-energy CP violation and leptogenesis became more accessible with the understanding of flavor effects. However, a definite well-motivated model where such a link occurs was still lacking. Adjoint SU(5) is a simple grand unified theory where neutrino masses are generated through the Type I and Type III seesaw mechanisms, and the lepton asy

N. R. Napolitano, A. J. Romanowsky, L. Coccato, M. Capaccioli

We present new Planetary Nebula Spectrograph observations of the ordinary elliptical galaxy NGC 4494, resulting in positions and velocities of 255 PNe out to 7 effective radii (25 kpc). We also present new wide-field surface photometry from MMT/Megacam, and long-slit stellar kinematics from VLT/FORS2. The spatial and kinematical distributions of the PNe agre

Uri Jacob, Tsvi Piran

We examine what the absorbed spectra of extra-galactic TeV gamma-ray sources, such as blazars, would look like in the presence of Lorentz invariance violation (LIV). Pair-production with the extra-galactic background light modifies the observed spectra of such sources, and we show that a violation of Lorentz invariance would generically have a dramatic effec

Bjoern Schenke, Michael Strickland, Adrian Dumitru, Yasushi Nara

We consider momentum broadening and energy loss of high momentum partons in a hot non-Abelian plasma due to collisions. We solve the coupled system of Wong-Yang-Mills equations on a lattice in real time, including binary hard elastic collisions among the partons. The collision kernel is constructed such that the total collisional energy loss and momentum bro

D. G. Hitlin, C. H. Cheng, D. M. Asner, T. Hurth

The sixth SuperB Workshop was convened in response to questions posed by the INFN Review Committee, evaluating the SuperB project at the request of INFN. The working groups addressed the capability of a high-luminosity flavor factory that can gather a data sample of 50 to 75 /ab in five years to elucidate New Physics phenomena unearthed at the LHC. This repo

Marc Kamionkowski

If the linear polarization of the cosmic microwave background (CMB) is rotated in a frequency-independent manner as it propagates from the surface of last scatter, it may introduce a B-mode polarization. Here I show that measurement of higher-order TE, EE, EB, and TB correlations induced by this rotation can be used to reconstruct the rotation angle as a fun

Samuel K. Lee, Shin&#39;ichiro Ando, Marc Kamionkowski

One of the targets of the recently launched Fermi Gamma-ray Space Telescope is a diffuse gamma-ray background from dark-matter annihilation or decay in the Galactic halo. N-body simulations and theoretical arguments suggest that the dark matter in the Galactic halo may be clumped into substructure, rather than smoothly distributed. Here we propose the gamma-

J. X. Ma, X. F. Liu, T. Lin, G. Y. Gao

We explore manganite interface magnetism in epitaxially grown La0.7Sr0.3MnO3(LSMO)/SrTiO3 ultrathin superlattices (SL) along (110) orientation. we show that robust ferromagnetism persists down to four monolayers LSMO(MLs) (~1.1 nm in thickness), of which 50% Mn is at the interface state. Above eight MLs, the magnetic moment is nearly saturated to the theoret

Yung-Fu Chen, Travis Dirks, Gassem Al-Zoubi, Norman Birge

We report measurements of the non-equilibrium electron energy distribution in carbon nanotubes. Using tunneling spectroscopy via a superconducting probe, we study the shape of the local electron distribution functions, and hence energy relaxation rates, in nanotubes that have bias voltages applied between their ends. At low temperatures, electrons interact w

Loison Hoi, James M. Cline

We systematically explore the parameter space of the state-of-the-art brane-antibrane inflation model (Baumann {\it et al}., arXiv:0706.0360, arXiv:0705.3837) which is one of the most rigorously derived from string theory, applying the cosmic background explorer normalization and constraint on the spectral index. We improve on previous treatments of upliftin

David Tsang, Dong Lai

Diskoseismic c-modes in accretion discs have been invoked to explain low-frequency variabilities observed in black-hole X-ray binaries. These modes are trapped in the inner-most region of the disc and have frequencies much lower than the rotation frequency at the disc inner radius. We show that because the trapped waves can tunnel through the evanescent barr

Yang-Shyang Li, Amina Helmi, Gabriella De Lucia, Felix Stoehr

We use a hybrid approach that combines high-resolution simulations of the formation of a Milky Way-like halo with a semi-analytic model of galaxy formation to study the mass content of dwarf galaxies in the concordance $Λ$CDM cosmology. We find that the mass within 600 pc of dark matter haloes hosting luminous satellites has a median value of $\sim 3.2\times

Tullio Ceccherini-Silberstein, Michel Coornaert

We present a uniform version of a result of M. Gromov on the surjunctivity of maps commuting with expansive group actions and discuss several applications. We prove in particular that for any group $Γ$ and any field $\K$, the space of $Γ$-marked groups $G$ such that the group algebra $\K[G]$ is stably finite is compact.

Sergei I. Ipatov, Michael F. A&#39;Hearn

Time variations in velocities and relative amount of observed particles (mainly icy particles with diameter d<3 μm) ejected from Comet 9P/Tempel 1 are studied based on analysis of the images made by Deep Impact (DI) cameras during the first 13 minutes after the collision of the DI impactor with the comet. Analysis of maxima or minima of plots of the time var

M. Reza Shaebani, Jalal Sarabadani

We numerically study a two-dimensional granular gas of rigid disks where an external driving force is applied to each particle in such a way that the system is driven into a steady state by balancing the energy input and the dissipation due to inelastic collisions. Two intruder particles embedded in this correlated medium experience a fluctuation-induced for

B. J. Overbosch, Claudio Chamon

We study the tunneling current between edge states of quantum Hall liquids across a single long contact region, and predict a resonance at a bias voltage set by the scale of the edge velocity. For typical devices and edge velocities associated with charged modes, this resonance occurs outside the physically accessible bias domain. However, for edge states th

Soebur Razzaque, Olga Mena, Charles D. Dermer

Protons accelerated in the internal shocks of a long duration gamma ray burst can escape the fireball as cosmic rays by converting to neutrons. Hadronic interactions of these neutrons inside a stellar wind bubble created by the progenitor star will produce TeV gamma rays via neutral meson decay and synchrotron radiation by charged pion-decay electrons in the