Research archive
arXiv papers from June 2009
The most recent 100 records published that month. Open any paper for its original abstract, citation metadata, related research, and reading tools.
K. Michaelian
Darwinian Theory depicts life as being overwhelmingly consumed by a fight for survival in a hostile environment. However, from a thermodynamic perspective, life is a dynamic, out of equilibrium process, stabilizing and coevolving in concert with its abiotic environment. The living component of the biosphere of greatest mass, the plants and cyanobacteria, are
A. R. Hernández, F. A. Pinheiro, C. H. Lewenkopf, E. R. Mucciolo
We investigate the influence of the Coulomb interaction on the adiabatic pumping current through quantum dots. Using nonequilibrium Green's functions techniques, we derive a general expression for the current based on the instantaneous Green's function of the dot. We apply this formula to study the dependence of the charge pumped per cycle on the time-depend
Vladimir Baranovsky, Victor Ginzburg
Let Y,Z be a pair of smooth coisotropic subvarieties in a smooth algebraic Poisson variety X. We show that any data of first order deformation of the structure sheaf O_X to a sheaf of noncommutative algebras and of the sheaves O_Y and O_Z to sheaves of right and left modules over the deformed algebra, respectively, gives rise to a Batalin-Vilkoviski algebra
James McNerney, J. Doyne Farmer, Sid Redner, Jessika E. Trancik
We study a simple model for the evolution of the cost (or more generally the performance) of a technology or production process. The technology can be decomposed into $n$ components, each of which interacts with a cluster of $d-1$ other, dependent components. Innovation occurs through a series of trial-and-error events, each of which consists of randomly cha
G. Lugones, A. G. Grunfeld, N. N. Scoccola, C. Villavicencio
We study the deconfinement transition of hadronic matter into quark matter under neutron star conditions assuming color and flavor conservation during the transition. We use a two-phase description. For the hadronic phase we use different parameterizations of a non-linear Walecka model which includes the whole baryon octet. For the quark matter phase we use
Martin Crocce, Pablo Fosalba, Francisco J. Castander, Enrique Gaztanaga
We introduce a new set of large N-body runs, the MICE simulations, that provide a unique combination of very large cosmological volumes with good mass resolution. They follow the gravitational evolution of ~ 8.5 billion particles (2048^3) in volumes covering up to 450 (Gpc/h)^3. Our main goal is to accurately model and calibrate basic cosmological probes tha
- Comparisons of the radial distributions of core-collapse supernovae with those of young and old stellar populationsastro-ph.CO
J. P. Anderson, P. A. James
We present observational constraints on the nature of core-collapse supernovae through an investigation into their radial distributions with respect to those of young and old stellar populations within their host galaxies, as traced by H-alpha emission and R-band light respectively. We discuss results and the implications they have on the nature of supernova
L. Monaco, I. Saviane, S. Perina, M. Bellazzini
Context. NGC 205 is a peculiar dwarf elliptical galaxy hosting in its center a population of young blue stars. Their origin is still matter of debate, the central fresh star formation activity possibly being related to dynamical interactions between NGC 205 and M31. Aims. The star formation history in the central 30\arcsec ($\sim$120 pc) around the NGC 205 c
Gorazd Cvetic, Hector E. Martinez
We consider the ``modified Minimal Analytic'' (mMA) coupling that involves an infrared cut to the standard MA coupling. The mMA coupling is a Stieltjes function and, as a consequence, the paradiagonal Pade approximants converge to the coupling in the entire $Q^2$-plane except on the time-like semiaxis below the cut. The equivalence between the narrow width a
- SUSY-QCD effects on neutralino dark matter annihilation beyond scalar or gaugino mass unificationhep-ph
Bjorn Herrmann, Michael Klasen, Karol Kovarik
We describe in detail our calculation of the full supersymmetric (SUSY) QCD corrections to neutralino annihilation into heavy quarks and extend our numerical analysis of the resulting dark matter relic density to scenarios without scalar or gaugino mass unification. In these scenarios, the final state is often composed of top quarks and the annihilation proc
- An Experimental Mathematics Perspective on the Old, and still Open, Question of When To Stop?math.PR
Luis A. Medina, Doron Zeilberger
In a recent article in American Scientist, Theodore Hill described a coin-tossing game whose pay-off is the number of heads over the total number of throws. Suppose that at a given point during the game you have 5 heads and 3 tails, should you stop and get 5/8, or should you keep playing, hoping to get a better score? This is still an open problem. In the pr
Nicolas Libedinsky
For extra-large Coxeter systems (m(s,r)>3), we construct a natural and explicit set of Soergel bimodules D={D_w}_{w\in W} such that each D_w contains as a direct summand (or is equal to) the indecomposable Soergel bimodule B_w. When decategorified, we prove that D gives rise to a set {d_w}_{w\in W} that is actually a basis of the Hecke algebra. This basis is
Ágnes Kóspál, David R. Ardila, Attila Moór, Péter Ábrahám
Dust in debris disks is generated by collisions among planetesimals. The existence of these planetesimals is a consequence of the planet formation process, but the relationship between debris disks and planets has not been clearly established. Here we analyze Spitzer/MIPS 24 and 70 micrometer data for 150 planet-bearing stars, and compare the incidence of de
Mauricio Girardi
In this Comment we discuss some points concerning the modeling of parked cars proposed in the article by Rawal and Rodgers, Physica A (2005). We also introduce another approach to this problem which leads to a better description of the empirical data collected by the authors.
Ronald G. Douglas, Gadadhar Misra, Jaydeb Sarkar
In this note, we show that a quasi-free Hilbert module R defined over the polydisk algebra with kernel function k(z, w) admits a unique minimal dilation (actually an isometric co-extension) to the Hardy module over the polydisk if and only if S^{-1}(z, w) k(z, w) is a positive kernel function, where S(z, w) is the Szeg\"{o} kernel for the polydisk. Moreover,
D. W. Berry, B. L. Higgins, S. D. Bartlett, M. W. Mitchell
We present the theory of how to achieve phase measurements with the minimum possible variance in ways that are readily implementable with current experimental techniques. Measurements whose statistics have high-frequency fringes, such as those obtained from NOON states, have commensurately high information yield. However this information is also highly ambig
- PHENIX Measurements of Azimuthal Anisotropy for $\pi^0$ Production at High $p_T$ in Au+Au Collisions at $\sqrt{s_{NN}}=200$GeVnucl-ex
Rui Wei
An improved measurement of $v_2$ for $\pi^0$ in a broad range of $p_T$ and centrality is presented. By combining $v_2$ with the $R_{AA}$, we provide new insights on jet-medium interactions. We show that current pQCD energy loss models cannot describe the suppression of the $\pi^0$ as a function of the angle with respect to the reaction plane. Our result coul
Pierre Artoisenet, Eric Braaten
A new mechanism for heavy quarkonium production in high-energy collisions called the "s-channel cut" was proposed in 2005 by Lansberg, Cudell, and Kalinovsky. We identify this mechanism physically as the production of a heavy quark and anti-quark that are on-shell followed by their rescattering to produce heavy quarkonium. We point out that in the NRQCD fact
Juan Gil, Thomas Krainer, Gerardo Mendoza
The paper proves the existence and elucidates the structure of the asymptotic expansion of the trace of the resolvent of a closed extension of a general elliptic cone operator on a compact manifold with boundary as the spectral parameter tends to infinity. The hypotheses involve only minimal conditions on the symbols of the operator. The results combine prev
- Integrated GHz silicon photonic interconnect with micrometer-scale modulators and detectorsphysics.optics
Long Chen, Kyle Preston, Sasikanth Manipatruni, Michal Lipson
We report an optical link on silicon using micrometer-scale ring-resonator enhanced silicon modulators and waveguide-integrated germanium photodetectors. We show 3 Gbps operation of the link with 0.5 V modulator voltage swing and 1.0 V detector bias. The total energy consumption for such a link is estimated to be ~120 fJ/bit. Such compact and low power monol
Tsevi Mazeh
This paper reviews the basic technical characteristics of the ground-based photometric searches for transiting planets, and discusses a possible observational selection effect. I suggest that additional photometric observations of the already observed fields might discover new transiting planets with periods around 4-6 days. The set of known transiting plane
Jean-Pierre Gazeau, Francesco Toppan
A non-commutative structure for de Sitter spacetime is naturally introduced by replacing ("fuzzyfication") the classical variables of the bulk in terms of the dS analogs of the Pauli-Lubanski operators. The dimensionality of the fuzzy variables is determined by a Compton length and the commutative limit is recovered for distances much larger than the Compton
Timothy J. Rodigas, Philip M. Hinz
(Abridged) The observed radial velocity (RV) eccentricity distribution for extrasolar planets in single-planet systems shows that a significant fraction of planets are eccentric ($e > 0.1$). Here we investigate the effects on an RV planet's eccentricity produced by undetected outer companions. We have carried out Monte Carlo simulations of mock RV data to un
Giovanni Russo, Mario di Bernardo, Eduardo D. Sontag
This paper addresses the problem of giving conditions for transcriptional systems to be globally entrained to external periodic inputs. By using contraction theory, a powerful tool from dynamical systems theory, it is shown that certain systems driven by external periodic signals have the property that all solutions converge to a fixed limit cycle. General r
Patrick Simon, Andy Taylor, Jan Hartlap
Combining redshift and galaxy shape information offers new exciting ways of exploiting the gravitational lensing effect for studying the large scales of the cosmos. One application is the three-dimensional reconstruction of the matter density distribution which is explored in this paper. We give a generalisation of an already known minimum-variance estimator
I. Horvath, L. G. Balazs, Z. Bagoly, J. Kelemen
Two classes of gamma-ray bursts have been identified in the BATSE catalogs characterized by durations shorter and longer than about 2 seconds. There are, however, some indications for the existence of a third type of burst. Swift satellite detectors have different spectral sensitivity than pre-Swift ones for gamma-ray bursts. Therefore it is worth to reanaly
Denis Krotov
A vertex coloring of a graph is called "perfect" if for any two colors $a$ and $b$, the number of the color-$b$ neighbors of a color-$a$ vertex $x$ does not depend on the choice of $x$, that is, depends only on $a$ and $b$ (the corresponding partition of the vertex set is known as "equitable"). A set of vertices is called "completely regular" if the coloring
Jun-Xian Wang, Sangeeta Malhotra, James E. Rhoads, Hao-Tong Zhang
We present a large sample of Ly-alpha emitting galaxies spectroscopically confirmed at z~4.5, based on IMACS spectroscopic observations of candidate LAEs in the LALA Cetus field. We identify 110 z~4.5 LAEs based on single line detections with no continuum emission blueward of the line. The Ly-alpha confirmation rate varies from <50% to 76% for candidates sel
- Tracking the impact of environment on the Galaxy Stellar Mass Function up to z~1 in the 10k zCOSMOS sampleastro-ph.CO
M. Bolzonella, K. Kovac, L. Pozzetti, E. Zucca
We study the impact of the environment on the evolution of galaxies in the zCOSMOS 10k sample in the redshift range 0.1<z<1.0 over an area of ~1.5 deg2. The considered sample of secure spectroscopic redshifts contains about 8500 galaxies, with their stellar masses estimated by SED fitting of the multiwavelength optical to NIR photometry. The evolution of the
Wouter G. Ellenbroek, Zorana Zeravcic, Wim van Saarloos, Martin van Hecke
We compare the elastic response of spring networks whose contact geometry is derived from real packings of frictionless discs, to networks obtained by randomly cutting bonds in a highly connected network derived from a well-compressed packing. We find that the shear response of packing-derived networks, and both the shear and compression response of randomly
Giovanni Bassanelli, Francois Berteloot
In the family of degree $d$ polynomials the hypersurfaces defined by the existence of a cycle of period $n$ and multiplier $e^{i\theta}$ are shown to equiditribute the bifurcation current.
- The relativistic entrainment matrix of a superfluid nucleon-hyperon mixture. II. Effect of finite temperaturesastro-ph.SR
M. E. Gusakov, E. M. Kantor, P. Haensel
We calculate the important quantity of superfluid hydrodynamics, the relativistic entrainment matrix for a nucleon-hyperon mixture at arbitrary temperature. In the nonrelativistic limit this matrix is also termed the Andreev-Bashkin or mass-density matrix. Our results can be useful for modeling the pulsations of massive neutron stars with superfluid nucleon-
E. R. Micelotta, B. R. Brandl, F. P. Israel
(Aims): We study the LMC interstellar medium in the field of the nebula N157B, which contains a supernova remnant, an OB association, ionized gas, and high-density dusty filaments in close proximity. We investigate the relative importance of shock excitation by the SNR and photo-ionization by the OB stars, as well as possible interactions between the superno
M. Kuhlen, P. Madau, J. Silk
The unambiguous detection of Galactic dark matter annihilation would unravel one of the most outstanding puzzles in particle physics and cosmology. Recent observations have motivated models in which the annihilation rate is boosted by the Sommerfeld effect, a non-perturbative enhancement arising from a long range attractive force. Here we apply the Sommerfel
H. J. de Vega, N. G. Sanchez
Cumulative observational evidence confirm that the surface gravity of dark matter (DM) halo mu_{0 D} = r_0 rho_0 where r_0 and rho_0 are the halo core radius and central density, respectively, is nearly constant and independent of galaxy luminosity for a high number of galactic systems (spirals, dwarf irregular and spheroidals, elliptics) spanning over 14 ma
D. Sobral, P. N. Best, J. E. Geach, Ian Smail
New results are presented, as part of the Hi-z Emission Line Survey (HiZELS), from the largest area survey to date (1.4 sq.deg) for Lyman-alpha emitters (LAEs) at z~9. The survey, which is primarily targeting H-alpha emitters at z<3, uses the Wide Field CAMera on the United Kingdom Infrared Telescope and a custom narrow-band filter in the J band and reaches
Brian Batell, Maxim Pospelov, Adam Ritz
We discuss the sensitivity of neutrino experiments at the luminosity frontier to generic hidden sectors containing new (sub)-GeV neutral states. The weak interaction of these states with the Standard Model can be efficiently probed through all of the allowed renormalizable `portals' (in the Higgs, vector, and neutrino sectors) at fixed target proton beam fac
- Search for a Higgs Boson Produced in Association with a W Boson in pbar-p Collisions at sqrt{s} = 1.96 TeVhep-ex
CDF Collaboration, T. Aaltonen
We present a search for a standard model Higgs boson produced in association with a W boson using 2.7 1/fb of integrated luminosity of pbar-p collision data taken at sqrt{s} = 1.96 TeV. Limits on the Higgs boson production rate are obtained for masses between 100 GeV and 150 GeV. Through the use of multivariate techniques, the analysis achieves an observed (
Joanna A. Ellis-Monaghan, Iain Moffatt
We consider two operations on an edge of an embedded graph (or equivalently a ribbon graph): giving a half-twist to the edge and taking the partial dual with respect to the edge. These two operations give rise to an action of S_3^{|E(G)|}, the ribbon group, on G. The action of the ribbon group on embedded graphs extends the concepts of duality, partial duali
C. Charmousis, T. Kolyvaris, E. Papantonopoulos
We present a generalisation of the charged C-metric conformally coupled with a scalar field in the presence of a cosmological constant. The solution is asymptotically flat or a constant curvature spacetime. The spacetime metric has the geometry of a usual charged C-metric with cosmological constant, where the mass and charge are equal. When the cosmological
- Measurement of binding energy of negatively charged excitons in GaAs/AlGaAs quantum wellscond-mat.str-el
V. V. Solovyev, I. V. Kukushkin
We report a photoluminescence study of electron-hole complexes in specially designed semiconductor heterostructures. Placing a remote dilute layer of donors at different distances \itshape d \normalfont from the quantum well leads to the transformation of luminescence spectra of neutral ($X$) and negatively charged ($X^{-}$) excitons. The onset of an additio
Charles Poli, Dmitry Savin, Olivier Legrand, Fabrice Mortessagne
We investigate the statistical properties of the complexness parameter which characterizes uniquely complexness (biorthogonality) of resonance eigenstates of open chaotic systems. Specifying to the regime of isolated resonances, we apply the random matrix theory to the effective Hamiltonian formalism and derive analytically the probability distribution of th
E. O'Sullivan, S. Giacintucci, J. M. Vrtilek, S. Raychaudhury
We present results from combined low-frequency radio and X-ray studies of nearby galaxy groups. We consider two main areas: firstly, the evolutionary process from spiral-dominated, HI-rich groups to elliptical-dominated systems with hot, X-ray emitting gas halos; secondly, the mechanism of AGN feedback which appears to balance radiative cooling of the hot ha
N. M. Law, S. R. Kulkarni, R. G. Dekany, E. O. Ofek
The Palomar Transient Factory (PTF) is a fully-automated, wide-field survey aimed at a systematic exploration of the optical transient sky. The transient survey is performed using a new 8.1 square degree camera installed on the 48-inch Samuel Oschin telescope at Palomar Observatory; colors and light curves for detected transients are obtained with the automa
Brendon J. Brewer, Matthew J. Francis
We demonstrate that the principle of maximum relative entropy (ME), used judiciously, can ease the specification of priors in model selection problems. The resulting effect is that models that make sharp predictions are disfavoured, weakening the usual Bayesian "Occam's Razor". This is illustrated with a simple example involving what Jaynes called a "sure th
Snigdhayan Mahanta
We show that a $KK$-equivalence between two unital $C^*$-algebras produces a correspondence between their DG categories of finitely generated projective modules which is a $\mathbf{K}_*$-equivalence, where $\mathbf{K}_*$ is Waldhausen's $K$-theory. We discuss some connections with strong deformations of $C^*$-algebras and homological dualities. Motivated by
- Adsorption of Externally Stretched Two-Dimensional Flexible and Semi-flexible Polymers near an Attractive Wallcond-mat.stat-mech
Pui-Man Lam, Yi Zhen, Haijun Zhou, Jie Zhou
We study analytically a model of a two dimensional, partially directed, flexible or semiflexible polymer, attached to an attractive wall which is perpendicular to the preferred direction. In addition, the polymer is stretched by an externally applied force. We find that the wall has a dramatic effect on the polymer. For wall attraction smaller than the non-s
F. Pont, G. Hebrard, J. M. Irwin, F. Bouchy
We recently reported the photometric and spectroscopic detection of the primary transit of the 111-day-period, eccentric extra-solar planet HD80606 b, at Observatoire de Haute-Provence, France (Moutou et al. 2009). The whole egress of the primary transit and a section of its central part were observed, allowing the measurement of the planetary radius, and ev
Saqib Saeed, Christoph Kunz
This paper describes the work done on Matrix Browser, which is a recently developed graphical user interface to explore and navigate complex networked information spaces. This approach presents a new way of navigating information nets in windows explorer like widget. The problem on hand was how to export arbitrary knowledge bases in Matrix Browser. This was
Emilio Musso, Lorenzo Nicolodi
We develop an approach to affine symplectic invariant geometry of Lagrangian surfaces by the method of moving frames. The fundamental invariants of elliptic Lagrangian immersions in affine symplectic four-space are derived together with their integrability equations. The invariant setup is applied to discuss the question of symplectic applicability for ellip
Robert Calderbank, Peter G. Casazza, Andreas Heinecke, Gitta Kutyniok
Fusion frame theory is an emerging mathematical theory that provides a natural framework for performing hierarchical data processing. A fusion frame is a frame-like collection of subspaces in a Hilbert space, thereby generalizing the concept of a frame for signal representation. In this paper, we study the existence and construction of fusion frames. We firs
- Magnetism of Substitutional Co Impurities in Graphene: Realization of Single $\pi$-Vacanciescond-mat.mes-hall
E. J. G. Santos, D. Sanchez-Portal, A. Ayuela
We report {\it ab initio} calculations of the structural, electronic and magnetic properties of a graphene monolayer substitutionally doped with Co (Co$_{sub}$) atoms. We focus in Co because among traditional ferromagnetic elements (Fe, Co and Ni), only Co$_{sub}$ atoms induce spin-polarization in graphene. Our results show the complex magnetism of Co substi
Pierluigi Contucci, Joel L. Lebowitz
It is shown that random quantum spin systems with centered disorder satisfy correlation inequalities previously proved (arXiv:cond-mat/0612371) in the classical case. Consequences include monotone approach of pressure and ground state energy to the thermodynamic limit. Signs and bounds on the surface pressures for different boundary conditions are also deriv
- Effect of platy- and leptokurtic distributions in the random-field Ising model: Mean field approachcond-mat.stat-mech
Silvio M. Duarte Queiros, Nuno Crokidakis, Diogo O. Soares-Pinto
The influence of the tail features of the local magnetic field probability density function (PDF) on the ferromagnetic Ising model is studied in the limit of infinite range interactions. Specifically, we assign a quenched random field whose value is in accordance with a generic distribution that bears platykurtic and leptokurtic distributions depending on a
Richard Canary, Peter Storm
Fixing a closed hyperbolic surface S, we define a moduli space AI(S) of unmarked hyperbolic 3-manifolds homotopy equivalent to S. This 3-dimensional analogue of the moduli space M(S) of unmarked hyperbolic surfaces homeomorphic to S has bizarre local topology, possessing many points that are not closed. There is, however, a natural embedding of M(S) into AI(
- Teaching Quality Assurance and Project Management to Undergraduate Computing Students in Pakistancs.CY
Zaigham Mehmood, Saqib Saeed
Software Project Management (SPM) and Software Quality Assurance (SQA) are key components of undergraduate Computing programmes at educational establishments in Pakistan. Because of the nature of these subjects, there are a number of issues that need to be discussed and resolved so that the teaching becomes more effective, students learning experience is mor
H. Santos, A. Ayuela, W. Jaskólski, M. Pelc
We study the origin of interface states in carbon nanotube intramolecular junctions between achiral tubes. By applying the Born-von Karman boundary condition to an interface between armchair- and zigzag-terminated graphene layers, we are able to explain their number and energies. We show that these interface states, costumarily attributed to the presence of
- Fast Reconnection in High-Lundquist-Number Plasmas Due to Secondary Tearing Instabilitiesphysics.plasm-ph
A. Bhattacharjee, Yi-Min Huang, H. Yang, B. Rogers
Thin current sheets in systems of large size that exceed a critical value of the Lundquist number are unstable to a super-Alfvenic tearing instability. The scaling of the growth rate of the fastest growing instability with respect to the Lundquist number is shown to follow from the classical dispersion relation for tearing modes. As a result of this instabil
- Meson-exchange currents and final-state interactions in quasielastic electron scattering at high momentum transfersnucl-th
J. E. Amaro, M. B. Barbaro, J. A. Caballero, T. W. Donnelly
The effects of meson-exchange currents (MEC) are computed for the one-particle one-hole transverse response function for finite nuclei at high momentum transfers $q$ in the region of the quasielastic peak. A semi-relativistic shell model is used for the one-particle-emission $(e,e')$ reaction. Relativistic effects are included using relativistic kinematics,
B. Z. Kopeliovich, Ivan Schmidt, M. Siddikov
We study photoabsorption reaction and real Compton scattering (RCS) within the color dipole model. We rely on a photon wave function derived in the instanton vacuum model, and on the energy dependent phenomenological elastic dipole amplitude. Data for the photoabsorption cross section at high energies agree with our parameter free calculations. We also provi
- Information Processing with Pure Spin Currents in Silicon: Spin Injection, Extraction, Manipulation and Detectioncond-mat.mtrl-sci
Olaf M. J. van "t Erve, Chaffra Awo-Affouda, Aubrey T. Hanbicki, Connie H. Li
We demonstrate that information can be transmitted and processed with pure spin currents in silicon. Fe/Al2O3 tunnel barrier contacts are used to produce significant electron spin polarization in the silicon, generating a spin current which flows outside of the charge current path. The spin orientation of this pure spin current is controlled in one of three
Pau Figueras, James Lucietti
We prove uniqueness theorems for asymptotically flat, stationary, extremal, vacuum black hole solutions, in four and five dimensions with one and two commuting rotational Killing fields respectively. As in the non-extremal case, these problems may be cast as boundary value problems on the two dimensional orbit space. We show that the orbit space for solution
T. E. Clark, Boyang Liu, S. T. Love, T. ter Veldhuis
The standard model Higgs boson can serve as the inflaton field of slow roll inflationary models provided it exhibits a large non-minimal coupling with the gravitational scalar curvature. The Higgs boson self interactions and its couplings with a standard model singlet scalar serving as the source of dark matter are then subject to cosmological constraints. T
Shlomo Dado, Arnon Dar
We use the cannonball model of gamma ray bursts (GRBs) and public data from the first day of observations of GRB 090618 to predict its X-ray and optical lightcurves until very late times, and, in particular, the emergence of a photometric and spectroscopic signature of an SN akin to SN1998bw in its optical afterglow with an anticipated peak brightness of mag
M. A. Betemps, M. V. T. Machado
The solution of non-linear evolution equations for dense nuclear gluon density has been suggested as one of the relevant mechanisms of pA and AA collisions at collider energies. Here we study a simple parameterization for the unintegrated gluon distribution using the knowledge of asymptotic solutions of the Balitsky-Kovchegov equation, describing high-energy
A. Wiranata, M. Prakash
We show that first approximations to the bulk viscosity $\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\eta_v$ on the factor $(\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variationa
Saurish Chakrabarty, Zohar Nussinov
We examine correlation functions in the presence of competing long and short ranged interactions to find multiple correlation and modulation lengths. We calculate the ground state stripe width of an Ising ferromagnet, frustrated by an arbitrary long range interaction. In large $n$ systems, we demonstrate that for a short range system frustrated by a general
PengFei Guan, Xi Zhang
This paper is devoted to the regularity analysis of a geodesic equation in the space of Sasakian metrics. Firstly, we reduce the geodesic equation in the space of Sasakian metrics to a Dirichlet problem of degenerate complex Monge-Amp\'ere type eqution on the K\"ahler cone; secondly, we obtain a priori etimates for the above equation. These a priori estimate
J. A. Gonzalez, F. S. Guzman, N. Montelongo-Garcia, T. Zannias
By a combination of analytical and numerical techniques, we demonstrate the existence of spherical, asymptotically flat traversable wormholes supported by exotic matter whose stress tensor relative to the orthonormal frame of Killing observers takes the form of a perfect fluid possessing anisotropic pressures and subject to linear equations of state: $\tau=\
Creighton K. Thomas, A. Alan Middleton
A sampling algorithm is presented that generates spin glass configurations of the 2D Edwards-Anderson Ising spin glass at finite temperature, with probabilities proportional to their Boltzmann weights. Such an algorithm overcomes the slow dynamics of direct simulation and can be used to study long-range correlation functions and coarse-grained dynamics. The
Ilja Dorsner, Svjetlana Fajfer, Jernej F. Kamenik, Nejc Kosnik
Motivated by the disagreement between experimental and lattice QCD results on the D_s decay constant we systematically reinvestigate role of leptoquarks in charm meson decays. We consider scalar leptoquarks that transform as a weak interaction triplet, doublet, or singlet in a model independent approach, and also argue that in a particular SU(5) GUT model th
Peyo Stoilov
Construction of analytic functions, which determine bounded Toeplitz operators
Jonathan Luk
We prove that sufficiently regular solutions to the wave equation $\Box_g\phi=0$ on the exterior of the Schwarzschild black hole obey the estimates $|\phi|\leq C_\delta v_+^{-{3/2}+\delta}$ and $|\partial_t\phi|\leq C_{\delta} v_+^{-2+\delta}$ on a compact region of $r$ and along the event horizon. This is proved with the help of a new vector field commutato
A. M. Kaufman, R. P. Anderson, Thomas M. Hanna, E. Tiesinga
We demonstrate and theoretically analyze the dressing of several proximate Feshbach resonances in Rb-87 using radio-frequency (rf) radiation. We present accurate measurements and characterizations of the resonances, and the dramatic changes in scattering properties that can arise through the rf dressing. Our scattering theory analysis yields quantitative agr
A I Olemskoi, S S Borysov, I A Shuda
We consider both analytically and numerically creation conditions of diverse hierarchical trees. A connection between the probabilities to create hierarchical levels and the probability to associate these levels into united structure is found. We argue a consistent probabilistic picture requires making use of the deformed algebra. Our consideration is based
Boaz Keren-Zur, Luca Mazzucato, Yaron Oz
We consider candidates for dark matter in models of gauge mediated supersymmetry breaking, in which the supersymmetry breaking sector is weakly coupled and calculable. Such models typically contain classically flat directions, that receive one-loop masses of a few TeV. These pseudo-flat directions provide a new mechanism to account for the cold dark matter r
Stéphane Merigon, Henrik Seppänen
We consider the (projective) representations of the group of holomorphic automorphisms of a symmetric tube domain $V\oplus i\Omega$ that are obtained by analytic continuation of the holomorphic discrete series. For a representation corresponding to a discrete point in the Wallach set, we find the decomposition under restriction to the identity component of $
- Citing and Reading Behaviours in High-Energy Physics. How a Community Stopped Worrying about Journals and Learned to Love Repositoriescs.DL
Anne Gentil-Beccot, Salvatore Mele, Travis Brooks
Contemporary scholarly discourse follows many alternative routes in addition to the three-century old tradition of publication in peer-reviewed journals. The field of High- Energy Physics (HEP) has explored alternative communication strategies for decades, initially via the mass mailing of paper copies of preliminary manuscripts, then via the inception of th
- Strong Taylor approximation of stochastic differential equations and application to the L\'evy LIBOR modelmath.PR
Antonis Papapantoleon, Maria Siopacha
In this article we develop a method for the strong approximation of stochastic differential equations (SDEs) driven by L\'evy processes or general semimartingales. The main ingredients of our method is the perturbation of the SDE and the Taylor expansion of the resulting parameterized curve. We apply this method to develop strong approximation schemes for LI
J. F. Gomes, G. Starvaggi Franca, G. R. de Melo, A. H. Zimerman
In this paper we provide an algebraic construction for the negative even mKdV hierarchy which gives rise to time evolutions associated to even graded Lie algebraic structure. We propose a modification of the dressing method, in order to incorporate a non-trivial vacuum configuration and construct a deformed vertex operator for $\hat{sl}(2)$, that enable us t
Alexander A. Govyadinov, George Y. Panasyuk, John C. Schotland
We propose a method for optical nano-imaging in which the structure of a three-dimensional inhomogeneous medium may be recovered from far-field power measurements. Neither phase control of the illuminating field nor phase measurements of the scattered field are necessary. The method is based on the solution to the inverse scattering problem for a system cons
J. E. Han
We investigate models of molecular junctions which constitute minimal Hamiltonians to account for zero-bias-anomaly and the satellite features of inelastic transport by molecular phonons. Through nonlinear transport calculations with the imaginary-time nonequilibrium formalism, a HOMO-LUMO model with Anderson-Holstein interaction is shown to produce co-tunne
A. Di Piazza, K. Z. Hatsagortsyan, C. H. Keitel
The quantum electrodynamical vacuum polarization effects arising in the collision of a high-energy proton beam and a strong, linearly polarized laser field are investigated. The probability that laser photons merge into one photon by interacting with the proton`s electromagnetic field is calculated taking into account the laser field exactly. Asymptotics of
J. Greenlees, B. Shipley
We show that the category of free rational G-spectra for a connected compact Lie group G is Quillen equivalent to the category of torsion differential graded modules over the polynomial cohomology ring on the classifying space, H*(BG). The ingredients are enriched Morita equivalences, functors making rational spectra algebraic, and Koszul duality and thick s
- Detection of very-high-energy gamma-ray emission from the vicinity of PSR B1706-44 with H.E.S.Sastro-ph.HE
S. Hoppe, E. de Oña-Wilhemi, B. Khélifi, R. C. G. Chaves
The energetic pulsar PSR B1706-44 and the adjacent supernova remnant (SNR) candidate G 343.1-2.3 were observed by H.E.S.S. during a dedicated observational campaign in 2007. A new source of very-high-energy (VHE; E > 100 GeV) gamma-ray emission, HESS J1708-443, was discovered with its centroid at RA(J2000) = 17h08m10s and Dec(J2000) = -44d21', with a statist
Matthias Beck, Ira M. Gessel, Sunyoung Lee, Carla D. Savage
Given integers $a_1, a_2, ..., a_n$, with $a_1 + a_2 + ... + a_n \geq 1$, a symmetrically constrained composition $\lambda_1 + lambda_2 + ... + lambda_n = M$ of $M$ into $n$ nonnegative parts is one that satisfies each of the the $n!$ constraints ${\sum_{i=1}^n a_i \lambda_{\pi(i)} \geq 0 : \pi \in S_n}$. We show how to compute the generating function of the
E. M. Shahverdiev
By using chaos synchronization between non-identical multiple time delay semiconductor lasers with optoelectronic feedbacks, we demonstrate numerically how fast dynamic logic gates can be constructed. The results may be helpful to obtain a computational hardware with reconfigurable properties.
N. L. Achouri, J. -C. Angélique, G. Ban, B. Bastin
A new and independent determination of the Gamow-Teller branching ratio in the beta-decay of 21Na is reported. The value obtained of 5.13 +- 0.43 % is in agreement with the currently adopted value and the most recent measurement. In contrast to previous experiments, the present method was based on the counting of the parent 21Na ions and the resulting 351 ke
Alejandro M. Lobos, Aníbal Iucci, Markus Müller, Thierry Giamarchi
We report on the reinforcement of superconductivity in a system consisting of a narrow superconducting wire weakly coupled to a diffusive metallic film. We analyze the effective phase-only action of the system by a perturbative renormalization-group and a self-consistent variational approach to obtain the critical points and phases at T=0. We predict a quant
- Disorder-sensitive superconductivity in the iron silicide Lu$_2$Fe$_3$Si$_5$ studied by the Lu-site substitutionscond-mat.supr-con
T. Watanabe, H. Sasame, H. Okuyama, K. Takase
We studied effect of non-magnetic and magnetic impurities on superconductivity in Lu$_2$Fe$_3$Si$_5$ by small amount substitution of the Lu site, which investigated structural, magnetic, and electrical properties of non-magnetic (Lu$_{1-x}$Sc$_x$)$_2$Fe$_3$Si$_5$, (Lu$_{1-x}$Y$_x$)$_2$Fe$_3$Si$_5$, and magnetic (Lu$_{1-x}$Dy$_x$)$_2$Fe$_3$Si$_5$. The rapid d
R. Sekhar Chivukula, Neil D. Christensen, Baradhwaj Coleppa, Elizabeth H. Simmons
We present the details of a deconstructed model that incorporates both Higgsless and top-color mechanisms. The model alleviates the tension between obtaining the correct top quark mass and keeping Delta rho small that exists in many Higgsless models. It does so by singling out the top quark mass generation as arising from a Yukawa coupling to an effective to
Marc Mars
The Penrose inequality gives a lower bound for the total mass of a spacetime in terms of the area of suitable surfaces that represent black holes. Its validity is supported by the cosmic censorship conjecture and therefore its proof (or disproof) is an important problem in relation with gravitational collapse. The Penrose inequality is a very challenging pro
Jacob B. Simon, John F. Hawley
Resistivity and viscosity have a significant role in establishing the energy levels in turbulence driven by the magnetorotational instability (MRI) in local astrophysical disk models. This study uses the Athena code to characterize the effects of a constant shear viscosity \nu and Ohmic resistivity \eta in unstratified shearing box simulations with a net tor
- The Discrepancy Between tau and e+e- Spectral Functions Revisited and the Consequences for the Muon Magnetic Anomalyhep-ph
M. Davier, A. Hoecker, G. Lopez Castro, B. Malaescu
We revisit the procedure for comparing the pi pi spectral function measured in tau decays to that obtained in e+e- annihilation. We re-examine the isospin-breaking corrections using new experimental and theoretical input, and find improved agreement between the tau- --> pi- pi0 nu_tau branching fraction measurement and its prediction using the isospin-breaki
Philippe Flajolet, Maryse Pelletier, Michele Soria
The well-know needle experiment of Buffon can be regarded as an analog (i.e., continuous) device that stochastically "computes" the number 2/pi ~ 0.63661, which is the experiment's probability of success. Generalizing the experiment and simplifying the computational framework, we consider probability distributions, which can be produced perfectly, from a dis
- A novel analysis of the effects of short range correlations in inclusive lepton scattering off nucleinucl-th
Chiara Benedetta Mezzetti, Claudio Ciofi degli Atti
It is shown that, if inclusive lepton scattering off nuclei at high momentum transfer is analyzed in terms of proper scaling variables, useful information on Nucleon-Nucleon short range correlations in nuclei can be obtained. The traditional approach to Y-scaling is critically analyzed and a novel approach to Y-scaling, which incorporates the effects from tw
Ting Yu, J. H. Eberly
We extend recent theoretical studies of entanglement dynamics in the presence of environmental noise, following the long-time interest of Krzysztof Wodkiewicz in the effects of stochastic models of noise on quantum optical coherences. We investigate the quantum entanglement dynamics of two spins in the presence of classical Ornstein-Uhlenbeck noise, obtainin
Guihua Tian, Shuquan Zhong
The perturbation method in supersymmetric quantum mechanics (SUSYQM) is used to study whether the spheroidal equations have the shape-invariance property. Expanding the super-potential term by term in the parameter alpha and solving it, we find that the superpotential loses its shape-invariance property upon to the second term. This first means that we could
Viqar Husain
We describe a link between the cosmological constant problem and the problem of time in quantum gravity. This arises by examining the relationship between the cosmological constant and vacuum energy in light of non-perturbative formulations of quantum gravity.
- Theory of vortex states in magnetic nanodisks with induced Dzyaloshinskii-Moriya interactionscond-mat.mes-hall
A. B. Butenko, A. A. Leonov, A. N. Bogdanov, U. K. Rößler
Vortex states in magnetic nanodisks are essentially affected by surface/interface induced Dzyaloshinskii-Moriya interactions. Within a micromagnetic approach we calculate the equilibrium sizes and shape of the vortices as functions of magnetic field, the material and geometrical parameters of nanodisks. It was found that the Dzyaloshinskii-Moriya coupling ca