July 2005 arXiv papers — page 8

Brigitte Hiller, Alexander A. Osipov, Alex H. Blin

The six-quark instanton induced 't Hooft interaction is considered in combination with the Nambu-Jona-Lasinio (NJL) type U_L(3)X U_R(3) chiral symmetric Lagrangian. We discuss the bosonization of this multi-quark interaction, taking the U_A(1) breaking as a perturbation. We discuss its relation with the usual approach.

A. Valcarce, H. Garcilazo, J. Vijande

We investigate the structure of the SU(3) octet and decuplet baryons employing a constituent quark model designed for the study of the baryon-baryon interaction and successfully applied to the meson spectra. The model considers through the interacting potential perturbative, one-gluon exchange, and non-perturbative, boson exchanges and confinement, aspects o

Jai Kumar Singhal, Sardar Singh, Ashok K Nagawat

We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross section in SM and MSSM with Higgs boson mass for various choices of MSSM parameters tan βand m\sub A. We observe that at fixed CM energy, in the SM, the total

J. P. B. C. de Melo

The light-front approach is applied to calculate the electromagnetic current for quark-antiquark bound states for the pion. The pion electromagnetic form factor is obtnaide from the "+" and "-" components of the electromagnetic current in the Drell-Yan frame, with different models of the pi-q\bar{q} vertex and the results for the pion electro

L. Cunqueiro, J. Dias de Deus, C. Pajares

We show that the multiplicity distribution associated to high $p_T$ events is given in terms of the total multiplicity distribution in an universal way due to the fact that these events are self-shadowed. In particular, the mean associated multiplicity is related to the fluctuations on the multiplicity distribution. In the framework of percolation of strings

Michael Grady

The 3-d Z(2) lattice gauge-Higgs theory is cast in a partial axial gauge leaving a residual Z(2) symmetry, global in two directions and local in one. It is shown both analytically and numerically that this symmetry breaks spontaneously in the Higgs phase and is unbroken in the confinement phase. Therefore they must be separated everywhere by a phase transiti

R. Jeffrey Wilkes

UNO (Underground Neutrino Observatory) is intended as a multi-purpose detector, potentially useful for purposes which may not have been considered at the time of its construction. UNO accomodates a comprehensive physics program, encompassing nucleon decay and lepton flavor physics, including the possibility of observing CP violation, grand unification scale

Belle Collaboration

We report a new measurement of the branching fraction of neutral $B$ meson decays $B^0\ra a_{1}^{\pm}(1260)π^{\mp}$ with \ensuremath{a_{1}^{\pm}(1260)\ra ρ^{0}π^{\pm}} and $ρ^0\ra pi^+π^-$ using $275\times 10^{6}$ BBar pairs collected by the Belle detector at the KEKBasymmetric-energy $e^{+}e^{-}$ collider. We measure the branching fraction $\mathcal{B}($B^0

John R. Klauder

The basic principles of Affine Quantum Gravity are presented in a pedagogical style with a limited number of equations.

Luc Blanchet

The theory of general relativity, which is extremely well verified by classic tests in the solar system as well as by the radiation of the binary pulsar, is one of the fundamental tools of nowadays astrophysics. It permits the computation of the gravitational wave form emitted during the inspiral phase of binary systems of neutron stars and black holes. Base

Rustam Ibadov, Burkhard Kleihaus, Jutta Kunz, Marion Wirschins

We construct new black hole solutions in Einstein-Yang-Mills theory. They are static, axially symmetric and asymptotically flat. They are characterized by their horizon radius and a pair of integers (k,n), where k is related to the polar angle and n to the azimuthal angle. The known spherically and axially symmetric EYM black holes have k=1. For k>1, pairs o

R. Rosas-Rodriguez

By considering the Einstein vacuum field equations linearized about the Minkowski metric, the evolution equations for the gauge-invariant quantities characterizing the gravitational field are written in a Hamiltonian form by using a conserved functional as Hamiltonian; this Hamiltonian is not the analog of the energy of the field. A Poisson bracket between f

Isabelle Gnaedig, Helene Kirchner

We propose a generic termination proof method for rewriting under strategies, based on an explicit induction on the termination property. Rewriting trees on ground terms are modeled by proof trees, generated by alternatively applying narrowing and abstracting steps. The induction principle is applied through the abstraction mechanism, where terms are replace

Jan Poland

A main problem of "Follow the Perturbed Leader" strategies for online decision problems is that regret bounds are typically proven against oblivious adversary. In partial observation cases, it was not clear how to obtain performance guarantees against adaptive adversary, without worsening the bounds. We propose a conceptually simple argument to resol

P. Melby, A. Prevost, D. A. Egolf, J. S. Urbach

We demonstrate the effect of the depletion force in experiments and simulations of vertically vibrated mixtures of large and small steel spheres. The system exhibits size segregation and a large increase in the pair correlation function of the large spheres for short distances that can be accurately described using a combination of the depletion potential de

John M. Martinis, K. B. Cooper, R. McDermott, Matthias Steffen

Dielectric loss from two-level states is shown to be a dominant decoherence source in superconducting quantum bits. Depending on the qubit design, dielectric loss from insulating materials or the tunnel junction can lead to short coherence times. We show that a variety of microwave and qubit measurements are well modeled by loss from resonant absorption of t

P. N. Bibikov

One-magnon problem for spin-ladders with exact singlet-rung ground state in arbitrary oriented constant and staggered magnetic fields is studied. For two special configurations when the both fields are parallel or perpendicular to each other the exact formulas for eigenstates and eigenvectors are presented. In the parallel case the one-magnon contribution to

Mark Vogelsberger, D. A. Garanin, Rolf Schilling

We stress that the so-called butterfly hysteresis curves observed in dynamical magnetization measurements on systems of low-spin magnetic molecules such as V-15 and V-6 are a signature of adiabatic Landau-Zener transitions rather than that of a phonon bottleneck. We investigate the magnetization dynamics analytically with the help of a simple relaxation theo

Lu Li, Yayu Wang, M. J. Naughton, S. Ono

Using high-resolution magnetometry we have investigated in detail the magnetization $M$ above the critical temperature $T_c$ in $\rm Bi_2Sr_2CaCu_2O_{8+δ}$. In a broad range of temperature $T$ above $T_c$, we find that $M(T,H)$ is strongly non-linear in the field $H$. We show that as $T\to T_c$, the susceptibility $χ(T,H)$ diverges to very large values ($χ\t

Z. Barticevic, M. Pacheco, J. Simonin, C. R. Proetto

The electronic structure of radially polarized excitons in structured nanorings is analyzed, with emphasis in the ground-state properties and their dependence under applied magnetic fields perpendicular to the ring plane. The electron-hole Coulomb attraction has been treated rigorously, through numerical diagonalization of the full exciton Hamiltonian in the

Sergio Caracciolo, Andrea Gambassi, Massimiliano Gubinelli, Andrea Pelissetto

We investigate the critical behavior of the two-dimensional randomly driven lattice gas, in which particles are driven along one of the lattice axes by an infinite external field with randomly changing sign. A finite-size scaling (FSS) analysis provides novel evidences that this model is not in the same universality class as the driven lattice gas with a con

N. A. Usov, Ching-Ray Chang, Zung-Hang Wei

The analytical theory for a ferromagnetic antiferromagnetic bilayer with a compensated interface has been developed using an explicit expression for the interfacial interaction energy density. A stability of a solution describing domain walls within ferromagnetic and antiferromagnetic films has been investigated. It is shown that even for high values of surf

Weida Wu, N. P. Ong, P. M. Chaikin

We present a detailed study of the Nernst effect N$_{zx}$ in (TMTSF)$_2$PF$_6$ as a function of temperature, magnetic field magnitude and direction and pressure. As previously reported there is a large resonant-like structure as the magnetic field is rotated through crystallographic directions, the Lebed Magic Angles. These Nernst effect resonances strongly

Jan Øystein Haavig Bakke, Thomas Ramstad, Alex Hansen

We measure the roughness exponent and the correlation length exponent of a stress-weighted percolation process in the central force model in 2D. The roughness exponent is found to be zeta = 0.75 \pm 0.03 and the correlation length exponent is found to be nu = 1.7 \pm 0.3. This result supports a conjecture that the fracture roughness for large scales is contr

Jian-Xin Zhu, A. V. Balatsky, T. P. Devereaux, Qimiao Si

We analyze the effects of the electronic coupling to bosonic modes in a d-wave superconductor. The role of the scattering due to boson on the momentum transfer between electronic states in the Brilloine zone is addressed. We consider specific examples of $B_{1g}$ phonon, breathing mode phonon and spin resonance at $(π,π)$. The Fourier spectrum of the energy

James Dufty, Aparna Baskaran, J. Javier Brey

The linear response of an isolated, homogeneous granular fluid to small spatial perturbations is studied by methods of non-equilibrium statistical mechanics. The long wavelength linear hydrodynamic equations are obtained, with formally exact expressions for the susceptibilities and transport coefficients. The latter are given in equivalent Einstein-Helfand a

Stefano Zapperi, Claudio Castellano, Francesca Colaiori, Gianfranco Durin

Crackling noise is a common feature in many dynamic systems [1-9], the most familiar instance of which is the sound made by a sheet of paper when crumpled into a ball. Although seemingly random, this noise contains fundamental information about the properties of the system in which it occurs. One potential source of such information lies in the asymmetric sh

E. A. Eliseev, M. D. Glinchuk

For the first time we proposed the model for the calculations of the relaxor ferroelectrics films properties in the framework of the random field theory. We took into account the misfit strain between film and substrate as well as surface piezoelectric effect that causes built-in electric field in the strained films. In the statistical theory framework we ca

Egor Babaev, Asle Sudbo, N. W. Ashcroft

Dissipationless quantum states, such as superconductivity and superfluidity, have attracted interest for almost a century. A variety of systems exhibit these macroscopic quantum phenomena, ranging from superconducting electrons in metals to superfluid liquids, atomic vapours, and even large nuclei. It was recently suggested that liquid metallic hydrogen coul

Xi Dai, Zhong Fang, Yu-Gui Yao, Fu-Chun Zhang

We study intrinsic spin Hall effect in p-type GaAs quantum well structure described by Luttinger Hamiltonian and a Rashba spin-orbit coupling arising from the structural inversion symmetry breaking. The Rashba term induces an energy level crossing in the lowest heavy hole subband, which gives rise to a resonant spin Hall conductance. The resonance may be use

Lei Guo, Erik Luijten

We study polymer-polymer phase separation in a common good solvent by means of Monte Carlo simulations of the bond-fluctuation model. Below a critical, chain-length dependent concentration, no phase separation occurs. For higher concentrations, the critical demixing temperature scales nonlinearly with the total monomer concentration, with a power law relativ

P. Zheng, J. L. Luo, G. T. Liu, Y. L. Zhang

We present the optical reflectance and conductivity spectra for non-oxide antiperovskite superconductor $MgCNi_{3}$ at different temperatures. The reflectance drops gradually over a large energy scale up to 33,000 cm$^{-1}$, with the presence of several wiggles. The reflectance has slight temperature dependence at low frequency but becomes temperature indepe

A. A. Sidorenko, G. Allodi, R. De Renzi, G. Balestrino

55Mn nuclear magnetic resonance and magnetization studies of the series of La0.67Sr0.33MnO3 thin films have been performed at low temperature. Two distinct lines were observed, at 322 MHz and 380 MHz, corresponding to two different phases, the former located at the interface, with localized charges, and the latter corresponding to the film bulk, with itinera

G. Orso, G. V. Shlyapnikov

We calculate the superfluid transition temperature for a two-component 3D Fermi gas in a 1D tight optical lattice and discuss a dimensional crossover from the 3D to quasi-2D regime. For the geometry of finite size discs in the 1D lattice, we find that even for a large number of atoms per disc, the critical effective tunneling rate for a quantum transition to

B. Huard, A. Anthore, Norman O. Birge, H. Pothier

In order to probe quantitatively the effect of Kondo impurities on energy exchange between electrons in metals, we have compared measurements on two silver wires with dilute magnetic impurities (manganese) introduced in one of them. The measurement of the temperature dependence of the electron phase coherence time on the wires provides an independent determi

Mikito Koshino, Tsuneya Ando

The quantum Hall effect is studied numerically in modulated two-dimensional electron systems in the presence of disorder. Based on the scaling property of the Hall conductivity as well as the localization length, the critical energies where the states are extended are identified. We find that the critical energies, which are distributed to each of the subban

Mikito Koshino, Tsuneya Ando

Motivated by recent experimental attempts to detect the Hofstadter butterfly, we numerically calculate the Hall conductivity in a modulated two-dimensional electron system with disorder in the quantum Hall regime. We identify the critical energies where the states are extended for each of butterfly subbands, and obtain the trajectory as a function of the dis

Brian D. Gerardot, Stefan Strauf, Michiel J. A. de Dood, Andrey M. Bychkov

We present an optical study of closely-spaced self-assembled InAs/GaAs quantum dots. The energy spectrum and correlations between photons subsequently emitted from a single pair provide not only clear evidence of coupling between the quantum dots but also insight into the coupling mechanism. Our results are in agreement with recent theories predicting that t

Helmut G. Katzgraber, I. A. Campbell

We have studied numerically the dynamics of spin glasses with Ising and XY symmetry (gauge glass) in space dimensions 2, 3, and 4. The nonequilibrium spin-glass susceptibility and the nonequilibrium energy per spin of samples of large size L_b are measured as a function of anneal time t_w after a quench to temperatures T. The two observables are compared to

S. Khlebnikov, Leonid P. Pryadko

To study the effect of disorder on quantum phase slips (QPS) in superconducting wires, we consider the plasmon-only model where disorder can be incorporated into a first-principles instanton calculation. We consider weak but general finite-range disorder and compute the formfactor in the QPS rate associated with momentum transfer. We find that the system map

Eric Bertin

We study a generalization of the one-dimensional disordered Potts model, which exhibits glassy properties at low temperature. The real space properties of inherent structures visited dynamically are analyzed through a decomposition into domains over which the energy is minimized. The size of these domains is distributed exponentially, defining a characterist

Ribhu K. Kaul, Denis Ullmo, Shailesh Chandrasekharan, Harold U. Baranger

We study the effect of mesoscopic fluctuations on a magnetic impurity coupled to a spatially confined electron gas with a temperature in the mesoscopic range (i.e. between the mean level spacing $Δ$ and the Thouless energy $E_{\rm Th}$). Comparing ``poor-man's scaling'' with exact Quantum Monte Carlo, we find that for temperatures larger than the

Smita Mathur, Dirk Grupe

We re-examine the locus of narrow line Seyfert 1 galaxies on the M_BH--sigma (black hole mass--bulge velocity dispersion) plane in the light of the results from large new optically selected samples. We find that (1) soft X-ray selected NLS1s have a lower ratio of BH mass to σ^{4}_{[OIII]} than broad line Seyfert 1 galaxies; this remains a robust statistical

S. M. O'Neill, I. L. Tregillis, T. W. Jones, Dongsu Ryu

We present a set of high-resolution 3D MHD simulations of steady light, supersonic jets, exploring the influence of jet Mach number and the ambient medium on jet propagation and energy deposition over long distances. The results are compared to simple self-similar scaling relations for the morphological evolution of jet-driven structures and to previously pu

Hsiao-Wen Chen, Jason X. Prochaska, Benjamin J. Weiner, John S. Mulchaey

We present a pilot study of the clustering properties of Lya absorbers with respect to known galaxies based on 112 Lya absorbers and 482 galaxies identified at z<0.5 along the sightline toward PKS0405-123. The principal goal is to determine the origin of Lya absorbers based on their cross-correlation amplitude with known galaxies and investigate a possible N

F. I. Cooperstock, S. Tieu

A galaxy is modeled as a stationary axially symmetric pressure-free fluid in general relativity. For the weak gravitational fields under consideration, the field equations and the equations of motion ultimately lead to one linear and one nonlinear equation relating the angular velocity to the fluid density. It is shown that the rotation curves for the Milky

Ignas Snellen

Recently, mid-infrared Spitzer observations have been presented that show the light decrement due to the passage of a planet behind its host star. These measurements of HD209458b and TrES-1 are the first detections of direct light from an extra-solar planet. Interpretation of these results in terms of planet equipartition temperature and bond albedo is howev

A. Villar-Sbaffi, N. St-Louis, Anthony F. J. Moffat, Vilppu Piirola

CX Cep (WR 151) is the WR+O binary (WN5+O5V) with the second shortest period known in our Galaxy. To examine the circumstellar matter distribution and to better constraint the orbital parameters and mass-loss rate of the WR star, we obtained broadband and multi-band (i.e. UBVRI) linear polarization observations of the system. Our analysis of the phase-locked

Almus Kenter, Stephen S. Murray, William R. Forman, Christine Jones

We present results from a Chandra survey of the nine square degree Bootes field of the NOAO Deep Wide-Field Survey (NDWFS). This XBootes survey consists of 126 separate contiguous ACIS-I observations each of approximately 5000 seconds in duration. These unique Chandra observations allow us to search for large scale structure and to calculate X-ray source sta

M. Sirianni, M. J. Jee, N. Benitez, J. P. Blakeslee

We present the photometric calibration of the HST Advanced Camera for Surveys (ACS). We give here an overview of the performance and calibration of the 2 CCD cameras, the Wide Field Channel (WFC) and the High Resolution Channel (HRC), and a description of the best techniques for reducing ACS CCD data. On-orbit observations of spectrophotometric standard star

A. M. J. Mortier, S. Serjeant, J. S. Dunlop, S. E. Scott

The SCUBA HAlf Degree Extragalactic Survey (SHADES) is a major blank-field extragalactic sub-mm survey underway at the James Clerk Maxwell telescope.SHADES aims to cover half a square degree at 450+850microns to a 4sigma depth of ~8mJy at 850microns. Two fields are being observed, the Subaru/XMM--Newton Deep Field (SXDF) and the Lockman Hole East. The survey

J. C. B. Papaloizou, E. Szuszkiewicz

We investigate orbital resonances expected to arise when a system of two planets, with masses in the range 1-4 Earth masses, undergoes convergent migration while embedded in a section of gaseous disc where the flow is laminar. We consider surface densities corresponding to 0.5-4 times that expected for a minimum mass solar nebula at 5.2 AU. Using hydrodynami

C. Borys, Ian Smail, S. C. Chapman, A. W. Blain

We analyze deep X-ray, optical and mid-infrared Spitzer observations of the CDF-N/GOODS-N region to study 13 submillimeter-detected galaxies (SMGs) with spectroscopic redshifts (median z=2.2). We find a correlation between the estimated stellar and X-ray luminosity, implying that masses of the black holes may be related to the stellar masses of their host ga

Manjari Bagchi, Monika Sinha, Mira Dey, Jishnu Dey

Surface tension (S) is due to the inward force experienced by particles at the surface and usually gravitation does not play an important role in this force. But in compact stars the gravitational force on the particles is very large and S is found to depend not only on the interactions in the strange quark matter, but also on the structure of the star, i.e.

S. K. Randall, G. Fontaine, P. Brassard, P. Bergeron

We investigate the potential of multi-colour photometry for partial mode identification in both long- and short-period variable subdwarf B stars. The technique presented is based on the fact that the frequency dependence of an oscillation&#39;s amplitude and phase bears the signature of the mode&#39;s degree index l, among other things. Unknown contributing

Gisela Maintz, Klaas S. de Boer

RR Lyrae stars in the Milky Way are good tracers to study the kinematic behaviour and spatial distribution of older stellar populations. A recently established well documented sample of 217 RR Lyr stars with V<12.5 mag, has been used to reinvestigate these structural parameters. The kinematic parameters allowed to calculate the orbits of the stars. Nearly 1/

E. O. Vasiliev, Yu. A. Shchekinov

We study the effects of HD molecules on thermochemical evolution of the primordial gas behind shock waves, possibly arised in the process of galaxy formation. We find the critical shock velocity when deuterium transforms efficiently into HD molecules which then dominate gas cooling. Above this velocity the shocked gas is able to cool down to the temperature

Gisela Maintz

RR Lyrae stars are of great importance for investigations of Galactic structure. However, a complete compendium of all RR-Lyraes in the solar neighbourhood with accurate classifications and coordinates does not exist to this day. Here we present a catalogue of 561 local RR-Lyrae stars V_max less equal 12.5 mag according to the magnitudes given in the Combine

The Pierre Auger Collaboration

Using the first surface detector data of the Pierre Auger Observatory, we present the results of a blind search for overdensities in the cosmic ray flux with respect to isotropic expectations. We consider two energy bands: 1<E<5 EeV and E>5 EeV at two angular scales: 5$^\circ$ and 15$^\circ$. We also report the results of searches for excesses in target dire

K. -P. Schroeder, M. Cuntz

We present a new semi-empirical relation for the mass loss of cool stellar winds, which so far has frequently been described by &#34;Reimers&#39; law&#34;. Originally, this relation was based solely on dimensional scaling arguments without any physical interpretation. In our approach, the wind is assumed to result from the spill-over of the extended chromosp

J. Orloff

We discuss a robust and fairly model-independent upper bound on the possible neutrino flux produced by neutralino annihilation in the center of our galaxy, and show that its detection with present or future neutrino telescopes is highly improbable. This bound is obtained by relating the neutrino flux to the gamma flux that would be produced in the same annih

D. Boyanovsky, H. J. de Vega, N. G. Sanchez

We obtain the effective inflaton potential during slow roll inflation by including the one loop quantum corrections to the energy momentum tensor from scalar curvature and tensor perturbations as well as quantum fluctuations from light scalars and light Dirac fermions generically coupled to the inflaton. During slow roll inflation there is a clean and unambi

P. Padovani

The Virtual Observatory (VO) will revolutionise the way we do Astronomy by allowing easy access to all astronomical data and by making the handling and analysis of datasets at various locations across the globe much simpler and faster. I report here on the need for the VO and its status in Europe, concentrating on the recently started EURO-VO project, and th

Aeree Chung, J. H. van Gorkom, Jeffery D. P. Kenney, Bernd Vollmer

We present preliminary results of VLA HI imaging of selected Virgo cluster galaxies. The goal is to study environmental effects on galaxy evolution. Our sample of 41 galaxies is spread throughout the cluster and spans a wide range in star formation properties. Here we present the total HI maps of 13 galaxies. We find a number of galaxies with extended HI tai

Jongsoo Kim, Dongsu Ryu

Turbulent flows are ubiquitous in astrophysical environments, and understanding density structures and their statistics in turbulent media is of great importance in astrophysics. In this paper, we study the density power spectra, $P_ρ$, of transonic and supersonic turbulent flows through one and three-dimensional simulations of driven, isothermal hydrodynami

D. Barnhill, P. Bauleo, M. T. Dova, J. Harton

The Pierre Auger Observatory is being used to study cosmic rays with energies larger than 10 EeV. An essential quantity that must be deduced from data is the lateral distribution function (LDF). Knowledge of the LDF is important for the reconstruction of the shower core and the shower direction. Here we describe how the LDF is measured using the large sample

J. A. Sellwood, Stacy S. McGaugh

The initial radial density profiles of dark matter halos are laid down by gravitational collapse in hierarchical structure formation scenarios and are subject to further compression as baryons cool and settle to the halo centers. We here describe an explicit implementation of the algorithm, originally developed by Young, to calculate changes to the density p

Pierre Auger Collaboration, C. Aramo, J. Brack, R. Caruso

The stability of the fluorescence telescopes of the Pierre Auger Observatory is monitored with the optical relative calibration setup. Optical fibers distribute light pulses to three different diffuser groups within the optical system. The total charge per pulse is measured for each pixel and compared with reference calibration measurements. This allows moni

M. Stopa, A. Vidan, T. Hatano, S. Tarucha

We calculate, via spin density functional theory (SDFT) and exact diagonalization, the eigenstates for electrons in a variety of external potentials, including double and triple dots. The SDFT calculations employ realistic wafer profiles and gate geometries and also serve as the basis for the exact diagonalization calculations. The exchange interaction J bet

I. Antoniadis, K. S. Narain, T. R. Taylor

We discuss the moduli-dependent couplings of the higher derivative F-terms $(\Tr W^2)^{h-1}$, where $W$ is the gauge N=1 chiral superfield. They are determined by the genus zero topological partition function $F^{(0,h)}$, on a world-sheet with $h$ boundaries. By string duality, these terms are also related to heterotic topological amplitudes studied in the p

Matthew W. Muterspaugh, Benjamin F. Lane, Maciej Konacki, Bernard F. Burke

delta Equulei is among the most well-studied nearby binary star systems. Results of its observation have been applied to a wide range of fundamental studies of binary systems and stellar astrophysics. It is widely used to calibrate and constrain theoretical models of the physics of stars. We report 27 high precision differential astrometry measurements of de

Gabriele Scheler

Background: The roles of neuromodulation in a neural network, such as in a cortical microcolumn, are still incompletely understood. Neuromodulation influences neural processing by presynaptic and postsynaptic regulation of synaptic efficacy. Neuromodulation also affects ion channels and intrinsic excitability. Methods: Synaptic efficacy modulation is an effe

Christopher D. Carone, Justin M. Conroy

We present improved models of trinification in five dimensions. Unified symmetry is broken by a combination of orbifold projections and a boundary Higgs sector. The latter can be decoupled from the theory, realizing a Higgsless limit in which the scale of exotic massive gauge fields is set by the compactification radius. Electroweak Higgs doublets are identi

K. Aryanpour, E. R. Dagotto, M. Mayr, T. Paiva

Inhomogeneous s-wave superconductivity is studied in the two-dimensional, square lattice attractive Hubbard Hamiltonian using the Bogoliubov-de Gennes (BdG) mean field approximation. We find that at weak coupling, and for densities mainly below half-filling, an inhomogeneous interaction in which the on-site interaction $U_i$ takes on two values, $U_i=0, 2U$

Thomas P. Hayes, Alistair Sinclair

We prove that any Markov chain that performs local, reversible updates on randomly chosen vertices of a bounded-degree graph necessarily has mixing time at least $Ω(n\log n)$, where $n$ is the number of vertices. Our bound applies to the so-called ``Glauber dynamics&#39;&#39; that has been used extensively in algorithms for the Ising model, independent sets,

J. Henn, C. Jarczak, E. Sokatchev

We propose a mechanism for calculating anomalous dimensions of higher-spin twist-two operators in N=4 SYM. We consider the ratio of the two-point functions of the operators and of their superconformal descendants or, alternatively, of the three-point functions of the operators and of the descendants with two protected half-BPS operators. These ratios are pro

S. Bueltmann

We report on the first measurement of the single spin analyzing power (A_N) at sqrt(s)=200GeV, obtained by the pp2pp experiment using polarized proton beams at the Relativistic Heavy Ion Collider (RHIC). Data points were measured in the four momentum transfer t range 0.01 < |t| < 0.03 (GeV/c)^2. Our result, averaged over the whole t-interval is about one sta

M. Ciuchini, M. Pierini, L. Silvestrini

Performing a fit to the available experimental data, we quantify the effect of long-distance contributions from penguin contractions in B^0 to J/psi K^0 decays. We estimate the deviation of the measured S_CP term of the time-dependent CP asymmetry from sin(2 beta) induced by these contributions and by the penguin operators. We find Delta S = 0.000 +- 0.012 (

I. Siddiqi, R. Vijay, M. Metcalfe, E. Boaknin

The &#34;quantronium&#34; is a superconducting qubit consisting of a split Cooper pair box in which a large tunnel junction is inserted. This circuit has a special bias point where the Larmor frequency is, to first order, insensitive to fluctuations in the bias parameters -- the charge of the box island and the phase of the large junction. At this optimal wo

Micheal S. Berger, Brandon Zerbe

We investigate the sensitivity of future photon-photon colliders to low scale gravity scenarios via the process $γγ\to ZZ$ where the Kaluza-Klein boson exchange contributes only when the initial state photons have opposite helicity. We contrast this with the situation for the process $γγ\to γγ$ where the $t$ and $u$ channel also contribute. We include the on

J Elisenda Grigsby

In this paper, we introduce a sequence of invariants of a knot K in S^3: the knot Floer homology groups of the preimage of K in the m-fold cyclic branched cover over K. We exhibit the knot Floer homology in the m-fold branched cover as the categorification of a multiple of the Turaev torsion in the case where the m-fold branched cover is a rational homology

Angela Kopp, Sudip Chakravarty

We revisit the interlayer tunneling theory of high temperature superconductors and formulate it as a mechanism by which the striking systematics of the transition temperature within a given homologous series can be understood. We pay attention not only to the enhancement of pairing, as was originally suggested, but also to the role of competing order paramet

Ali Taghavi

We present some questions and suggestion on the second part of the Hilbert 16th problem

N. Tetradis

We consider the possibility that the dark matter is coupled through its mass to a scalar field associated with the dark energy of the Universe. In order for such a field to play a role at the present cosmological distances, it must be effectively massless at galactic length scales. We discuss the effects of the field on the distribution of dark matter in gal

Ugo Aglietti, Giulia Ricciardi, Giancarlo Ferrera

We evaluate thresholds resummed spectra in B -> Xu l nu decays in next-to-leading order. We present results for the distribution in E_X and in m_X^2/E_X^2, for the distribution in E_X and E_l and for the distribution in E_X, where E_X and m_X are the energy and the invariant mass of the final hadronic state Xu respectively and E_l is the energy of the charge

David Bachman, Saul Schleimer, Eric Sedgwick

We show that if two 3-manifolds with toroidal boundary are glued via a `sufficiently complicated&#39; map then every Heegaard splitting of the resulting 3-manifold is weakly reducible. Additionally, if Z is a manifold obtained by gluing X and Y, two connected small manifolds with incompressible boundary, along a closed surface F. Then the genus g(Z) of Z is

Howard Baer, Tadas Krupovnickas, Stefano Profumo, Piero Ullio

The focus point region of supersymmetric models is compelling in that it simultaneously features low fine-tuning, provides a decoupling solution to the SUSY flavor and CP problems, suppresses proton decay rates and can accommodate the WMAP measured cold dark matter (DM) relic density through a mixed bino-higgsino dark matter particle. We present the focus po

William P. Orrick

We define several operations that switch substructures of Hadamard matrices thereby producing new, generally inequivalent, Hadamard matrices. These operations have application to the enumeration and classification of Hadamard matrices. To illustrate their power, we use them to greatly improve the lower bounds on the number of equivalence classes of Hadamard

Andrzej Niedzwiecki, Andrzej A. Zdziarski

We study spectra generated by Comptonization of soft photons by cold electrons radially free-falling onto a black hole. We use a Monte Carlo method involving a fully relativistic description of Comptonization in the Kerr space-time. In agreement with previous studies, we find that Comptonization on the bulk motion of free fall gives rise to power-law spectra

Duiliu-Emanuel Diaconescu, Bogdan Florea

We construct the topological partition function of local nontoric del Pezzo surfaces using the ruled vertex formalism.

Silvio Franz

In this note we discuss metastability in a long-but-finite range disordered model for the glass transition. We show that relaxation is dominated by configuration belonging to metastable states and associate an in principle computable free-energy barrier to the equilibrium relaxation time. Adam-Gibbs like relaxation times appear naturally in this approach.

M. S. Borysova, Yu. M. Sinyukov, S. V. Akkelin, B. Erazmus

We analyze single particle momentum spectra and interferometry radii in central Au+Au collisions at RHIC within a hydro-inspired parametrization accounting for continuous hadron emission through the whole lifetime of hydrodynamically expanding fireball. We found that a satisfactory description of the data is achieved for a physically reasonable set of parame

V. I. Shnyrkov, Th. Wagner, D. Born, S. N. Shevchenko

We investigated both theoretically and experimentally dynamic features of a phase-biased charge qubit consisting of a single-Cooper-pair transistor closed by a superconducting loop. The effective inductance of the qubit was probed by a high-quality tank circuit. In the presence of a microwave power, with a frequency of the order of the qubit energy level sep

B. C. Allanach, C. G. Lester

We calculate the likelihood map in the full 7 dimensional parameter space of the minimal supersymmetric standard model (MSSM) assuming universal boundary conditions on the supersymmetry breaking terms. Simultaneous variations of m_0, A_0, M_{1/2}, tan beta, m_t, m_b and alpha_s(M_Z) are applied using a Markov chain Monte Carlo algorithm. We use measurements

S. Colafrancesco, S. Profumo, P. Ullio

We study the astrophysical implications of neutralino dark matter annihilations in galaxy clusters, with a specific application to the Coma cluster. We first address the determination of the dark halo models for Coma, starting from structure formation models and observational data, and we discuss in detail the role of sub-halos. We then perform a thorough an

Pavel Etingof, Andre Henriques, Joel Kamnitzer, Eric Rains

We compute the Poincare polynomial and the cohomology algebra with rational coefficeints of the manifold M_n of real points of the moduli space of algebraic curves of genus 0 with n labeled points. This cohomology is a quadratic algebra, and we conjecture that it is Koszul. We also compute the 2-local torsion in the cohomology of M_n. As was shown by E. Rain

B. Giacomazzo, L. Rezzolla

We discuss the procedure for the exact solution of the Riemann problem in special relativistic magnetohydrodynamics (MHD). We consider both initial states leading to a set of only three waves analogous to the ones in relativistic hydrodynamics, as well as generic initial states leading to the full set of seven MHD waves. Because of its generality, the soluti

Patrick Le Meur

Let A be a basic finite dimensional and connected algebra over an algebraically closed field k with zero characteristic. If the ordinary quiver of A has no double bypasses, we show that A admits a Galois covering which satisfies a universal property with respect to the Galois coverings of A. This universal property is similar to the one of the universal cove

A. Hayashi, M. Horibe, T. Hashimoto

We address a problem of identifying a given pure state with one of two reference pure states, when no classical knowledge on the reference states is given, but a certain number of copies of them are available. We assume the input state is guaranteed to be either one of the two reference states. This problem, which we call quantum pure state identification, i

N. Bartolo, Edward W. Kolb, A. Riotto

We investigate the possibility that the amplitude of scalar density perturbations may be damped after inflation. This would imply that CMB anisotropies do not uniquely fix the amplitude of the perturbations generated during inflation and that the present tensor-to-scalar ratio might be larger than produced in inflation, increasing the prospects of detection