September 2006 arXiv papers — page 5

J. -M. Gerard, E. Kou

We estimate the density matrix element for the pi^0, eta and eta' production from the vacuum in the large-N_c limit. As a consequence, we find that the QCD axial anomaly leads to highly non-trivial corrections to the usual flavour SU(3) relations between B^0-> K^0 pi^0, B^0-> K^0 eta and B^0-> K^0 eta' decay amplitudes. These corrections may explain

G. C. Branco, R. Gonzalez Felipe, F. R. Joaquim

Flavor effects due to lepton interactions in the early Universe may have played an important role in the generation of the cosmological baryon asymmetry through leptogenesis. If the only source of high-energy CP violation comes from the left-handed leptonic sector, then it is possible to establish a bridge between flavored leptogenesis and low-energy leptoni

S. Kraml, A. R. Raklev

We present a new method to search for a light scalar top (stop), decaying dominantly into $c\tildeχ^0_1$, at the LHC. The principal idea is to exploit the Majorana nature of the gluino, leading to same-sign top quarks in events of gluino pair production followed by gluino decays into top and stop. We demonstrate the reach of our method in terms of the gluino

A. Djouadi, M. M. Muhlleitner, M. Spira

We present the program package SUSY-HIT for the computation of supersymmetric particle decays within the framework of the Minimal Supersymmetric extension of the Standard Model. The code is based on two existing programs HDECAY and SDECAY for the calculation of the decay widths and branching ratios of, respectively, the MSSM Higgs bosons and the SUSY particl

Anna Hasenfratz, Roland Hoffmann

We measure the low lying eigenmodes of an overlap Dirac operator on 2--flavor staggered configurations. By comparing the eigenmode distribution to the predictions of Random Matrix Theory we test to what accuracy staggered configurations describe continuum QCD. The agreement between the numerical data and RMT implies that at our quark mass values the lattice

Anna Hasenfratz, Roland Hoffmann

Growing evidence indicates that in the continuum limit the rooted staggered action is in the correct QCD universality class, the non-local terms arising from taste breaking can be viewed as lattice artifacts. In this paper we consider the 2-flavor Asqtad staggered action at a lattice spacing of approximately 0.13 fm and probe the properties of the staggered

M. Hatakeyama, H. Sawanaka, H. So

We present a new method to introduce rotationally invariant terms in staggered fermions which is based on an $SO(2D)$ Clifford algebra formulation, where $D$ means the number of space-time dimensions. We have four candidates for improved mass terms that can split the degenerate mass of staggered fermions. Among them, we analyze three types of combinations an

Damiano Guazzini, Rainer Sommer, Nazario Tantalo

We compute the mass of the b-quark and the B_s meson decay constant in quenched lattice QCD using a combination of HQET and the standard relativistic QCD Lagrangian. We start from a small volume, where one can directly deal with the b-quark, and compute the evolution to a big volume, where the finite size effects are negligible through step scaling functions

Anthony Duncan

An effective field theory exists describing a very large class of biophysically interesting Coulomb gas systems: the lowest order (mean-field) version of this theory takes the form of a generalized Poisson-Boltzmann theory. Interaction terms depend on details (finite-size effects, multipole properties, etc). Convergence of the loop expansion holds only if mu

Stefan Schaefer

An overview of the current status of algorithmic approaches to dynamical overlap fermions is given. In particular the issue of changing the topological sector is discussed.

Iorwerth Owain Thomas, Simon Hands

We present results from a Monte Carlo simulation of non-compact lattice QED in 3 dimensions in which an explicit anisotropy $κ$ between $x$ and $y$ hopping terms has been introduced into the action. Using a parameter set corresponding to broken chiral symmetry in the isotropic limit $κ=1$, we study the chiral condensate on $16^3$, $20^3$, and $24^3$ lattices

G. Cossu, M. D'Elia, A. Di Giacomo, B. Lucini

We investigate the dual superconductivity mechanism in the exceptional group $G_2$. This is a centerless group (no 't Hooft flux vortices are allowed) and we check for the presence of a magnetic monopole condensate in the confined phase by measuring on the lattice a disorder parameter related to the vacuum expectation value of an operator carrying magnet

The MIPP Upgrade Collaboration

The upgraded MIPP physics results are needed for the support of NuMI projects, atmospheric cosmic ray and neutrino programs worldwide and will permit a systematic study of non-perturbative QCD interctions. The MIPP TPC is the largest contributor to the MIPP event size by far. Its readout system and electronics were designed in the 1990's and limit it to

L3 Collaboration

Measurements of inclusive production of the Lambda, Xi- and Xi*(1530) baryons in two-photon collisions with the L3 detector at LEP are presented. The inclusive differential cross sections for Lambda and Xi- are measured as a function of the baryon transverse momentum, pt, and pseudo-rapidity, eta. The mean number of Lambda, Xi- and Xi*(1530) baryons per hadr

S. Ghassemi, S. Khakshournia, R. Mansouri

We consider a planar gravitating thick domain wall of the $λϕ^4$ theory as a spacetime with finite thickness glued to two vacuum spacetimes on each side of it. Darmois junction conditions written on the boundaries of the thick wall with the embedding spacetimes reproduce the Israel junction condition across the wall in the limit of infinitesimal thickness. T

Yi Ling, Song He, Hongbao Zhang

The kinematics of particles moving in rainbow spacetime is studied in this paper. In particular the geodesics of a massive particle in rainbow flat spacetime is obtained when the semi-classical effect of its own energy on the background is taken into account. We show that in general the trajectory of a freely falling particle remains unchanged which is still

Yi Ling

The formalism of rainbow gravity is studied in a cosmological setting. We consider the very early universe which is radiation dominated. A novel treatment in our paper is to look for an ``averaged'' cosmological metric probed by radiation particles themselves. Taking their cosmological evolution into account, we derive the modified Friedmann-Robertso

Hadi Rahiminia, Massoud Amini

In this paper we prove a separability criterion for mixed states in $\mathbb C^p\otimes\mathbb C^q$. We also show that the density matrix of a graph with only one entangled edge is entangled.

Michael Chertkov, Vladimir Y. Chernyak

We illustrate the utility of the recently developed loop calculus for improving the Belief Propagation (BP) algorithm. If the algorithm that minimizes the Bethe free energy fails we modify the free energy by accounting for a critical loop in a graphical representation of the code. The log-likelihood specific critical loop is found by means of the loop calcul

Daniel Dantchev, Joseph Rudnick, M. Barmatz

We study critical point finite-size effects in the case of the susceptibility of a film in which interactions are characterized by a van der Waals-type power law tail. The geometry is appropriate to a slab-like system with two bounding surfaces. Boundary conditions are consistent with surfaces that both prefer the same phase in the low temperature, or broken

S. I. Hernandez, I. Santamaria-Holek, Carlos I. Mendoza, L. F. del Castillo

We present a mesoscopic hydrodynamic description of the dynamics of colloidal suspensions. We consider the system as a gas of Brownian particles suspended in a Newtonian heat bath subjected to stationary non-equilibrium conditions imposed by a velocity field. Using results already obtained in previous studies in the field by means of a generalized Fokker-Pla

Bogdan-Ioan Popa, Steven A. Cummer

We determine rigorously the effective permeability of magnetic metamaterials composed of passive particles exhibiting magnetic resonances. The effective permeability is expressed in terms of circuit parameters characteristic to these particles (L, C, and R) and particle geometry. The derivation takes into account the magnetic coupling between particles. We s

Kwangmoo Kim, David Stroud

The high-T_c cuprate superconductors are now believed to be intrinsically inhomogeneous. We develop a theory to describe how this inhomogeneity affects the intermodulation coefficient of such a material. We show that the continuum equations describing intermodulation in a superconducting layer with spatially varying properties are formally equivalent to thos

Arkadiusz Wojs, John J. Quinn

The nu=5/2 fractional quantum Hall state is studied numerically, directly including the effects of electron scattering between neighboring Landau levels. Significant reduction of the excitation gap caused by the LL mixing explains the discrepancy between earlier calculations and experiments. On the other hand, LL mixing also considerably reduces overlaps wit

Bin W. Zhang, David Jasnow, Daniel M. Zuckerman

Despite their importance in activated processes, transition-event durations -- which are much shorter than first passage times -- have not received a complete theoretical treatment. We therefore study the distribution of durations of transition events over a barrier in a one-dimensional system undergoing over-damped Langevin dynamics.

Fatemeh Tabatabaei, Gunter M. Schütz

Using an analytically tractable lattice model for reaction-diffusion processes of hard-core particles we demonstrate that under nonequilibrium conditions phase coexistence may arise even if the system is effectively one-dimensional as e.g. in the channel system of some zeolites or in artificial optical lattices. In our model involving two species of particle

N. Maire, F. Hohls, T. Luedtke, K. Pierz

We present noise measurements of self-assembled InAs quantum dots at high magnetic fields. In comparison to I-V characteristics at zero magnetic field we notice a strong current overshoot which is due to a Fermi-edge singularity. We observe an enhanced suppression in the shot noise power simultaneous to the current overshoot which is attributed to the electr

Zhen-zhong Zhang, Kai Chang

We investigate theoretically the ground-state configurations of two-dimensional charged-particle systems with an elliptical hard-wall boundary and their vibrational eigenmodes. The systems exhibit a series of structural transitions, finally changing from a zigzag structure to a one-dimensional Coulomb chain, as the eccentricity of the elliptical hard-wall bo

M. Yu. Kharitonov, K. B. Efetov

We calculate the Hall conductivity $\sig_{xy}$ and resistivity $ρ_{xy}$ of a granular system at large tunneling conductance $g_{T}\gg 1$. We show that in the absence of Coulomb interaction the Hall resistivity depends neither on the tunneling conductance nor on the intragrain disorder and is given by the classical formula $ρ_{xy}=H/(n^* e c)$, where $n^*$ di

Sanjeev Kumar, Arno P. Kampf, Pinaki Majumdar

We study a two dimensional, two-band double-exchange model for $e_g$ electrons coupled to Jahn-Teller distortions in the presence of quenched disorder using a recently developed Monte-Carlo technique. In the absence of disorder the half-filled system at low temperatures is an orbitally ordered ferromagnetic insulator with a staggered pattern of Jahn-Teller d

Jun-Wen Mao, You-Quan Li

We propose a model with a quantized degree of freedom to study the heat transport in quasi-one dimensional system. Our simulations reveal three distinct temperature regimes. In particular, the intermediate regime is characterized by heat conductivity with a temperature exponent $γ$ much greater than 1/2 that was generally found in systems with point-like par

M. Micoulaut, P. Boolchand, J. C. Phillips

We review in this paper the signatures of a new elastic phase that is found in glasses with selected compositions. It is shown that in contrast with random networks, where rigidity percolates at a single threshold, networks that are able to self-organize to avoid stress will remain in an almost stress- free state during a compositional interval, an intermedi

C. Brügger, C. P. Hofmann, F. Kämpfer, M. Pepe

Using the low-energy effective field theory for magnons and holes -- the condensed matter analog of baryon chiral perturbation theory for pions and nucleons in QCD -- we study different phases of doped antiferromagnets. We systematically investigate configurations of the staggered magnetization that provide a constant background field for doped holes. The mo

M. Micoulaut, L. Cormier, G. S. Henderson

Germanium dioxide ($GeO_2$) is a chemical analogue of $SiO_2$. Furthermore, it is also to some extent a structural analogue, as the low and high-pressure short-range order (tetrahedral and octahedral) is the same. However, a number of differences exist. For example, the $GeO_2$ phase diagram exhibits a smaller number of polymorphs, and all three $GeO_2$ phas

Seiji Kajita, Takashi Nakayama, Maki Kawai

A new repeated-slab calculation method is developed to simulate the electronic structures of charged surfaces by arranging density-variable charged sheets in vacuum regions to realize a constant potential on the charged sheets and maintain the charge neutrality condition. The charged sheets are fabricated so as to screen an electric field from charged slabs;

Enrico Prati, Marco Fanciulli, Alessandro Calderoni, Giorgio Ferrari

We report on the change of the characteristic times of the random telegraph signal (RTS) in a MOSFET operated under microwave irradiation up to 40 GHz as the microwave field power is raised. The effect is explained by considering the time dependency of the transition probabilities due to a harmonic voltage generated by the microwave field that couples with t

T. Meunier, I. T. Vink, L. H. Willems van Beveren, K-J. Tielrooij

We observe an experimental signature of the role of the phonons in spin relaxation between triplet and singlet states in a two-electron quantum dot. Using both the external magnetic field and the electrostatic confinement potential, we change the singlet-triplet energy splitting from 1.3 meV to zero and observe that the spin relaxation time depends non-monot

Michael Schulz, Steffen Trimper, Knud Zabrocki

We consider a reaction-diffusion process with retardation. The particles, immersed in traps initially, remain inactive until another particle is annihilated spontaneously with a rate $λ$ at a certain point $\vec x$. In that case the traps within a sphere of radius $R(t)= v t^α$ around $\vec x$ will be activated and a particle is released with a rate $μ$. Due

Jorden A. van Dam, Yuli V. Nazarov, Erik P. A. M. Bakkers, Silvano De Franceschi

When two superconductors become electrically connected by a weak link a zero-resistance supercurrent can flow. This supercurrent is carried by Cooper pairs of electrons with a combined charge of twice the elementary charge, e. The 2e charge quantum is clearly visible in the height of Shapiro steps in Josephson junctions under microwave irradiation and in the

Nicholas E. Singh-Miller, Damian A. Scherlis, Nicola Marzari

The functionality of conjugated polymer systems often relies on oxidations or reductions, in most cases mediated by the presence of counterions. The effect that the common counterion hexafluorophosphate (PF6-) has on the intermolecular interactions between charged oligothiophenes is investigated here using ab initio quantum chemistry methods. Counterions are

J. W. Harter, B. M. Andersen, J. Bobroff, M. Gabay

We study a model of a d-wave superconductor with strong potential scatterers in the presence of antiferromagnetic correlations and apply it to experimental nuclear magnetic resonance (NMR) results on Zn impurities in the superconducting state of YBCO. We then focus on the contribution of impurity-induced paramagnetic moments, with Hubbard correlations in the

Chung-Pin Chou, T. K. Lee, Chang-Ming Ho

We discuss recent progress of understanding the phenomena observed in high Tc cuprates by studying the d-wave resonating-valence-bond (d-RVB) based trial wave functions for the 2-dimensional t-J-type models. Treat exactly the strong correlation between electrons by numerical approach, we examine the evolution of ground states described by different variation

S. Prosandeev, L. Bellaiche

An atomistic approach is used to investigate finite-temperature properties of ferroelectric nanodots that are embedded in a polarizable medium. Different phases are predicted, depending on the ferroelectric strengths of the material constituting the dot and of the system forming the medium. In particular, novel states, exhibiting a coexistence between two ki

Mangala Prasad Singh, Baptiste Carvello, Laurent Ranno

We report the fabrication of an oxide-specific type of magnetoresistive junction, which is a ferromagnetic bilayer. Both electrodes are high spin-polarization oxides: magnetite (Fe3O4) and manganite (La0.7Sr0.3MnO3). Negligible magnetic coupling between both ferromagnetic electrodes is realised, which allows to obtain parallel and antiparallel magnetic confi

P. Silvestrini, R. Russo, V. Corato, B. Ruggiero

We investigate the properties of Josephson junction networks with inhomogeneous architecture. The networks are shaped as "quare comb" planar lattices on which Josephson junctions link superconducting islands arranged in the plane to generate the pertinent topology. Compared to the behavior of reference linear arrays, the temperature dependencies of t

G. M. MacAlpine, T. C. Ecklund, W. R. Lester, S. J. Vanderveer

We present and discuss correlations for optical and near-infrared (5500-10030 angstroms) line intensity measurements at many positions in the Crab Nebula. These correlations suggest the existence of gas produced by a range of nuclear processing, from material in which synthesis ended with the CNO-cycle, to some helium-burning and nitrogen depletion, to regio

R. L. Mutel, J. D. Menietti, I. W. Christopher, D. A. Gurnett

We describe the statistical properties of narrowband drifting auroral kilometric radiation ('striated' AKR) based on observations from the Cluster wideband receiver during 2002-2005. We show that the observed characteristics, including frequency drift rate and direction, narrow bandwidth, observed intensity, and beaming angular sizes are all consiste

Benjamin F. Collins, Hilke E. Schlichting, Re'em Sari

We examine the growth of eccentricities of a population of particles with initially circular orbits around a central massive body. Successive encounters between pairs of particles increase the eccentricities in the disk on average. As long as the epicyclic motions of the particles are small compared to the shearing motion between Keplerian orbits, there is n

Ian M. Hoffman, W. M. Goss, Patrick Palmer

Observations of two of the formaldehyde (H2CO) masers (A and D) in Sgr B2 using the VLBA+Y27 (resolution ~0.01&#34;) and the VLA (resolution ~9&#34;) are presented. The VLBA observations show compact sources (<10 milliarcseconds, <80 AU) with brightness temperatures >10^8 K. The maser sources are partially resolved in the VLBA observations. The flux densitie

Aristotle Socrates, Shane W. Davis, Omer Blaes

Turbulent Comptonization, a potentially important damping and radiation mechanism in relativistic accretion flows, is discussed. Particular emphasis is placed on the physical basis, relative importance, and thermodynamics of turbulent Comptonization. The effects of metal-absorption opacity on the spectral component resulting from turbulent Comptonization is

Michael J. Kurtz, Guenther Eichhorn, Alberto Accomazzi, Carolyn Grant

Technical libraries are currently experiencing very rapid change. In the near future their mission will change, their physical nature will change, and the skills of their employees will change. While some will not be able to make these changes, and will fail, others will lead us into a new era.

James Liebert, Adam J. Burgasser

We explore and discount the hypothesis that the strong, continual H$α$-emitting T dwarf 2MASS J12373919+6526148 can be explained as a young, low gravity, very low mass brown dwarf. The source is already known to have a marginally-fainter absolute magnitude than similar T dwarfs with trigonometric parallax measurements, and has a tangential velocity consisten

Victor P. Debattista, Ignacio Ferreras, Anna Pasquali, Anil Seth

{\it Hubble Space Telescope} (\hst) Wide Field Planetary Camera 2 ({\it WFPC2}) images of the Virgo Cluster dwarf elliptical galaxy VCC 128 reveal an apparently double nucleus. The two components, which are separated by $\sim 32$ pc in projection, have the same magnitude and color. We present a spectrum of this double nucleus and show that it is inconsistent

Ruth A. Daly, S. G. Djorgovski

Understanding the acceleration of the universe and its cause is one of the key problems in physics and cosmology today, and is best studied using a variety of mutually complementary approaches. Daly and Djorgovski (2003, 2004) proposed a model independent approach to determine the expansion and acceleration history of the universe and a number of important p

Maria J. Cruz, Matt J. Jarvis, Katherine M. Blundell, Steve Rawlings

We present basic observational data on the 6C** sample. This is a new sample of radio sources drawn from the 151 MHz 6C survey, which was filtered with radio criteria chosen to optimize the chances of finding radio galaxies at z > 4. The filtering criteria are a steep-spectral index and a small angular size. The final sample consists of 68 sources from a reg

Maria T. Beltran, Riccardo Cesaroni, Claudio Codella, Leonardo Testi

Theory predicts and observations confirm that low-mass stars (like the Sun) in their early life grow by accreting gas from the surrounding material. But for stars ~ 10 times more massive than the Sun (~10 M_sun), the powerful stellar radiation is expected to inhibit accretion and thus limit the growth of their mass. Clearly, stars with masses >10 M_sun exist

Lih-Sin The, Mounib F. El Eid, Bradley S. Meyer

We present a detailed study of s-process nucleosynthesis in massive stars of solar-like initial composition and masses 15, 20,25, and 30 Msun. We update our previous results of s-process nucleosynthesis during the core He-burning of these stars and then focus on an analysis of the s-process under the physical conditions encountered during the shell-carbon bu

I. Patrikeev, A. Fletcher, R. Stepanov, R. Beck

We have developed a technique of isolating elongated structures in galactic images, such as spiral arms, using anisotropic wavelets and apply this to maps of the CO, infrared and radio continuum emission of the grand-design spiral galaxy M51. Systematic shifts between the ridges of CO, infrared and radio continuum emission that are several $\kpc$ long are id

Richard de Grijs, Alasdair R. I. Robertson

Using high spatial resolution Hubble Space Telescope/Advanced Camera for Surveys archival imaging observations of Arp 116, centred on the elliptical galaxy NGC 4649, we explore the novel technique of pixel-by-pixel analysis of the galaxy&#39;s colour-magnitude diagramme to search for any evidence of recent enhanced star formation due to the apparent tidal in

B. Famaey, F. Pont, X. Luri, S. Udry

The nature of the Hyades stream, or Hyades moving group, is a long-standing question of Galactic Astronomy. Is this stream caused by non-axisymmetric perturbations of the galactic potential, such as transient or quasi-stationary spiral waves, or by the on-going evaporation of the Hyades cluster? A simple observational test has been designed to answer that qu

Eric I. Barnes, Liliya L. R. Williams, Arif Babul, Julianne J. Dalcanton

It has long been realized that dark matter halos formed in cosmological N-body simulations are characterized by density profiles rho(r) that, when suitably scaled, have similar shapes. Additionally, combining the density and velocity dispersion profiles sigma(r), each of which have decidedly nonpower-law shapes, leads to quantity rho/(sigma^3) that is a powe

T. J. Waskett, B. Sibthorpe, M. J. Griffin

The SPIRE Photometer Simulator reproduces the entire Herschel-SPIRE system in a modular IDL program. Almost every aspect of the operation of SPIRE can be investigated in a systematic way to ensure that observations are performed in the most efficient way possible when Herschel flies. This paper describes some of the work done with the Simulator to help prepa

M. Trichas, M. Rowan-Robinson, I. Waddington, T. S. R Babbedge

We have carried out a deep (21.5<R<23.9) systematic survey of galaxies selected from SWIRE using GMOS to target X-ray sources, AGN and galaxies with photometric redshifts greater than 1. We have obtained a total of 198 redshifts, of which 132 have secure redshifts in the range 0.12<z<1.21. This sample, combined with the 111 redshifts targeted with WIYN in th

Hrvoje Stefancic

The equation of state of dark energy is investigated to determine how much it may deviate from the equation of state of the cosmological constant (CC). Two aspects of the problem are studied: the &#34;expansion&#34; around the vacuum equation of state and the problem of the crossing of the cosmological constant boundary.

Caroline Terquem, John C. B. Papaloizou

The existence of extrasolar planets with short orbital periods suggests that planetary migration induced by tidal interaction with the protoplanetary disk is important. Cores and terrestrial planets may undergo migration as they form. In this paper we investigate the evolution of a population of cores with initial masses in the range 0.1-1 earth mass embedde

E. Suarez-Garcia, W. Hajdas, C. Wigger, K. Arzner

The degree of linear polarization in solar flares has not yet been precisely determined despite multiple attempts to measure it with different missions. The high energy range in particular has very rarely been explored, due to its greater instrumental difficulties. We approached the subject using the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI) sa

Goran Ostlin, Robert J. Cumming, Nils Bergvall

We present high-resolution echelle spectroscopy, obtained with the UVES spectrograph on ESO/VLT, of two luminous star clusters in the metal-poor blue compact galaxy ESO 338-IG04 at a distance of 37.5 Mpc. Cross-correlating with template stars, we obtain line-of-sight velocity dispersions of 33 and 17 km/s. By combining with size estimates from Hubble Space T

Daniel C. Kiminki, Henry A. Kobulnicky, K. Kinemuchi, Jennifer S. Irwin

We conducted a radial velocity survey of the Cygnus OB2 Association over a 6 year (1999 - 2005) time interval to search for massive close binaries. During this time we obtained 1139 spectra on 146 OB stars to measure mean systemic radial velocities and radial velocity variations. We spectroscopically identify 73 new OB stars for the first time, the majority

Yu-Qing Lou, Yang Gao

Self-similar shock solutions in spherically symmetric polytropic gas flows are constructed and analyzed in contexts of proto-star formation processes. Among other possible solutions, we model a similarity shock across the sonic critical curve with an inner free-fall core collapse and a simultaneous outer expansion of the extended envelope; the separation or

Timothy R. Bedding, Hans Kjeldsen

There has been tremendous progress in observing oscillations in solar-type stars. In a few short years we have moved from ambiguous detections to firm measurements. We review the recent results, most of which have come from high-precision Doppler measurements. We also review briefly the results on giant and supergiant stars and the prospects for the future.

I. V. Moskalenko, S. W. Digel, T. A. Porter, O. Reimer

We discuss uncertainties and possible sources of errors associated with the determination of the diffuse Galactic gamma-ray emission using the EGRET data. Most of the issues will be relevant also in the GLAST era. The focus here is on issues that impact evaluation of dark matter annihilation signals against the diffuse gamma-ray emission of the Milky Way.

Tamara Bogdanovic, Britton D. Smith, Michael Eracleous, Steinn Sigurdsson

We model the electromagnetic emission signatures of massive black hole binaries (MBHBs) with an associated gas component. The method comprises numerical simulations of relativistic binaries and gas coupled with calculations of the physical properties of the emitting gas. We calculate the accretion powered UV/X-ray and Halpha light curves and the Halpha emiss

Tim Naylor, Rob Jeffries

We present a maximum likelihood method for fitting two-dimensional model distributions to stellar data in colour-magnitude space. This allows one to include (for example) binary stars in an isochronal population. The method also allows one to derive formal uncertainties for fitted parameters, and assess the likelihood that a good fit has been found. We use t

Rolando D. Somma, Cristian D. Batista, Gerardo Ortiz

We present a new approach to study the thermodynamic properties of $d$-dimensional classical systems by reducing the problem to the computation of ground state properties of a $d$-dimensional quantum model. This classical-to-quantum mapping allows us to deal with standard optimization methods, such as simulated and quantum annealing, on an equal basis. Conse

Mu-Chun Chen, K. T. Mahanthappa

Strong correlations between leptogenesis and low energy CP violating leptonic processes have been shown by us to exist in the minimal left-right symmetric model with spontaneous CP violation. In this note, we investigate the implications of this model for the electric dipole moment of the electron. With an additional broken U(1)_H symmetry, the seesaw scale

Nikolaos Kidonakis

I present a calculation of threshold soft-gluon corrections to single top quark production in ppbar collisions via all partonic processes in the t and s channels and via associated top quark and W boson production. The soft-gluon corrections are formally resummed to all orders, and finite-order expansions of the resummed cross section are calculated through

Gabriel Vigny

We study the dynamics near infinity of polynomial mappings $f$ in $\mathbb{C}^2$. We assume that $f$ has indeterminacy points and is non constant on the line at infinity $L_\infty$. If $L_\infty$ is $f$-attracting, we decompose the Green current along itineraries defined by the indeterminacy points and their preimages. The symbolic dynamics that arises is a

J. Gorosabel, V. Larionov, A. J. Castro-Tirado, S. Guziy

We have performed optical polarimetric observations of the SN2006aj associated to the X-ray flash (XRF) of February 18, 2006, XRF060218 that provide information on its expansion geometry. The data were acquired in the R-band with the 0.7m telescope of Crimea, 2.5m Nordic Optical Telescope and the 2.2m of Calar Alto. We report the detection of linear polariza

I. Shapiro

We explore the relationship between de Rham and Lie algebra cohomologies in the finite dimensional and affine settings. As an application, we describe the BRST reduction of the chiral Hecke algebra as a vertex super algebra.

Stefano Zibetti, Brice Menard, Daniel B. Nestor, Anna M. Quider

We present a statistical analysis of the photometric properties and spatial distribution of more than 2,800 MgII absorbers with 0.37<z<1 and rest equivalent width W_0(\lambda2796)>0.8Ådetected in SDSS quasar spectra. Using an improved image stacking technique, we measure the cross-correlation between MgII gas and light (in the g, r, i and z-bands) from 10 to

Roberto B. Diener, Qi Zhou, Hui Zhai, Tin-Lun Ho

We show that the current method of determining superfluidity in optical lattices based on a visibly sharp bosonic momentum distribution $n({\bf k})$ can be misleading, for even a normal Bose gas can have a similarly sharp $n({\bf k})$. We show that superfluidity in a homogeneous system can be detected from the so-called visibility $(v)$ of $n({\bf k})$ $-$ t

Mitya Boyarchenko, Vladimir Drinfeld

This article is based on lectures given by the authors in 2005 and 2006. Our first goal is to present an introduction to the orbit method with an emphasis on the character theory of finite nilpotent groups. The second goal (motivated by a recent work of G. Lusztig) is to explain several nontrivial aspects of character theory for finite groups of the form $G(

Marco Hering, Marc Scheffler, Martin Dressel, Hilbert v. Lohneysen

Electronic transport in highly doped but still insulating silicon at low temperatures is dominated by hopping between localized states; it serves as a model system of a disordered solid for which the electronic interaction can be investigated. We have studied the frequency-dependent conductivity of phosphorus-doped silicon in the THz frequency range (30 GHz

T. Kluge, K. Rabbertz, M. Wobisch

We present a method for very fast repeated computations of higher-order cross sections in hadron-induced processes for arbitrary parton density functions. A full implementation of the method for computations of jet cross sections in Deep-Inelastic Scattering and in Hadron-Hadron Collisions is offered by the "fastNLO" project. A web-interface for online calcu

Yaacov Shapira, Valdir Bindilatti

Theoretycal results on the magnetization and susceptibility of a Heisenberg diluted antiferromagnet in the square lattice are given. The models considered have two exchange constants (J1-J2 and J1-J3) of which the second is much smaller than the first (lopsided models). Cluster statistics for clusters with up to 5 spins is given. A procedure to account for t

Yugui Yao, Yongcheng Liang, Di Xiao, Qian Niu

To justify the origin of anomalous Hall effect (AHE), it is highly desirable to have the system parameters tuned continuously. By quantitative calculations, we show that the doping dependent sign reversal in CuCr$_{2}$Se$_{4-x}$Br$_{x}$, observed but not understood, is nothing but direct evidence for the Berry-Phase mechanism of AHE. The systematic calculati

R. G. Edgar

Purely hydrodynamic numerical experiments into the evolution of astrophysical discs typically include some sort of viscosity in order to cause accretion. In this paper, we demonstrate an alternative method of implementing viscous forces, with extremely good angular momentum conservation properties. The method is based on altering the cell fluxes, rather than

Masato Arai, Sami Saxell, Anca Tureanu

A minimal supersymmetric standard model on noncommutative space-time (NC MSSM) is proposed. The model fulfils the requirements of noncommutative gauge invariance and absence of anomaly. The existence of supersymmetry with a scale of its breaking lower than the noncommutative scale is crucial in order to achieve a consistent gauge symmetry breaking.

Fergus Simpson

Here we consider a scenario in which dark energy is associated with the apparent area of a surface in the early universe. In order to resemble the cosmological constant at late times, this hypothetical reference scale should maintain an approximately constant physical size during an asymptotically de-Sitter expansion. This is found to arise when the particle

Ralph Blumenhagen, Mirjam Cvetic, Timo Weigand

We systematically investigate instanton corrections from wrapped Euclidean D-branes to the matter field superpotential of various classes of N=1 supersymmetric D-brane models in four dimensions. Both gauge invariance and the counting of fermionic zero modes provide strong constraints on the allowed non-perturbative superpotential couplings. We outline how th

Dan Knopf, Andrea Young

We show that there exists a suitable neighborhood of a constant curvature hyperbolic metric such that, for all initial data in this neighborhood, the corresponding solution to a normalized cross curvature flow exists for all time and converges to a hyperbolic metric. We show that the same technique proves an analogous result for Ricci flow. Additionally, we

Yongle Yu

We present a microscopic, many-body argument for supersolidity. We also illustrate the origin of rotons in a Bose system.

Yongle Yu

We investigate the properties of dispersion spectra of one-dimensional periodic Bose systems with repulsive interparticle interactions. These systems with sufficient large interactions can support metastable supercurrent states, which correspond to the local minima of the dispersion spectra at non-zero momenta. The existence of local minima in the spectra an

Shay Zucker, Tal Alexander

High-precision radial-velocity techniques, which enabled the detection of extrasolar planets are now sensitive to relativistic effects in the data of spectroscopic binary stars (SBs). We show how these effects can be used to derive the absolute masses of the components of eclipsing single-lined SBs and double-lined SBs from Doppler measurements alone. High-p

A. V. Kiselev, T. Wolf

A classification problem is proposed for supersymmetric evolutionary PDE that satisfy the assumptions of nonlinearity and nondegeneracy. Four classes of nonlinear coupled boson-fermion systems are discovered under the homogeneity assumption |f|=|b|=|D_t|=1/2. The syntax of the Reduce package SsTools, which was used for intermediate computations, and the appl

Stanislav Kuperstein, Oded Mintkevich, Jacob Sonnenschein

We construct the pp-wave string associated with the Penrose limit of $Y^{p,q}$ and $L^{p,q,r}$ families of Sasaki-Einstein geometries. We identify in the dual quiver gauge theories the chiral and the non-chiral operators that correspond to the ground state and the first excited states. We present an explicit identification in a prototype model of $L^{1,7,3}$

H. Casini

We consider some formulations of the entropy bounds at the semiclassical level. The entropy S(V) localized in a region V is divergent in quantum field theory (QFT). Instead of it we focus on the mutual information I(V,W)=S(V)+S(W)-S(V\cup W) between two different non-intersecting sets V and W. This is a low energy quantity, independent of the regularization

Andrea Dainese

The Large Hadron Collider at CERN will open a new energy domain for heavy-ion physics. Besides ALICE, the dedicated heavy-ion experiment, also ATLAS and CMS are preparing rich physics programs with nucleus-nucleus collisions. Here we focus on open heavy-flavour and quarkonia studies, among the fields that will most benefit from the high centre-of-mass energy

D. Grumiller, R. Jackiw

We descry and discuss a duality in 2-dimensional dilaton gravity.

Ctirad Klimcik

We review the description of a particular deformation of the WZW model. The resulting theory exhibits a Poisson-Lie symmetry with a non-Abelian cosymmetry group and can be vectorially gauged.