July 2008 arXiv papers — page 5

J. S. Valverde, Onofre Rojas, S. M. de Souza.

The asymmetric tetrahedron is composed by all edges of tetrahedron represented by Ising interaction except one, which has a Heisenberg type interaction. This asymmetric tetrahedron is arranged connecting a vertex which edges are only Ising type interaction to another vertex with same structure of another tetrahedron. The process is replicated and this kind o

Loretta Bartolini

When a Dehn filled link manifold contains a geometrically incompressible one-sided surface, it is shown there is a unique boundary incompressible position that the surface can take in the link space. The proof uses a version of the sweep-out technique from two-sided Heegaard splitting theory. When applied to one-sided Heegaard splittings, this result can be

Y. He, S. Burov, R. Metzler, E. Barkai

Single particle tracking of mRNA molecules and lipid granules in living cells shows that the time averaged mean squared displacement $\overline{δ^2}$ of individual particles remains a random variable while indicating that the particle motion is subdiffusive. We investigate this type of ergodicity breaking within the continuous time random walk model and show

Zhiyong Xu, Yuri S. Kivshar

We study the properties of surface solitons generated at the edge of a semi-infinite photonic lattice in nonlinear quadratic media, namely two-color surface lattice solitons. We analyze the impact of phase mismatch on existence and stability of surface modes, and find novel classes of two-color twisted surface solitons which are stable in a large domain of t

Zhiyong Xu

We address surface soliton complexes formed at the edge of annular guiding structures containing several concentric rings. Such soliton complexes feature a -phase difference between neighboring spots. It is shown that the multipole-mode solitons can rotate steadily upon propagation, and the existence domain is strongly affected by the rotation frequency. The

Tetsufumi Tanamoto, Koji Maruyama, Yu-xi Liu, Xuedong Hu

We show an efficient purification protocol in solid-state qubits by replacing the usual bilateral CNOT gate by the bilateral iSWAP gate. We also show that this replacement can be applied to breeding and hashing protocols, which are useful for quantum state purification. These replacements reduce the number of fragile and cumbersome two-qubit operations, maki

Zhiyong Xu, Bjorn Maes, Xunya Jiang, John D. Joannopoulos

We uncover a strong coupling between nonlinearity and diffraction in a photonic crystal at the supercollimation point. We show this is modeled by a nonlinear diffraction term in a nonlinear schroedinger type equation, in which the properties of solitons are investigated. Linear stability analysis shows solitons are stable in an existence domain that obeys th

P. Reig

We have investigated the spectral and timing variability of four accreting X-ray pulsars with Be-type companions during major X-ray outbursts. Different spectral states were defined according to the value of the X-ray colours and flux. Transient Be/X-ray binaries exhibit two branches in their colour-colour and colour-intensity diagrams: the horizontal branch

Koichi Fujimoto, Shuji Ishihara, Kunihiko Kaneko

Segmentation in arthropod embryogenesis represents a well-known example of body plan diversity. Striped patterns of gene expression that lead to the future body segments appear simultaneously or sequentially in long and short germ-band development, respectively. Regulatory genes relevant for stripe formation are evolutionarily conserved among arthropods, the

Jhan Srbinovsky, Stuart Wyithe

The fraction of ionizing photons which escape their host galaxy and so are able to ionize hydrogen in the inter-galactic medium (IGM) is a critical parameter in studies of the reionization era and early galaxy formation. In this paper we combine observations of Lyman-alpha absorption towards high redshift quasars with the measured UV luminosity function of h

Qihou Liu

In this paper, we study the asymptotic behavior of the colored Jones polynomials evaluated at roots of unity for a special class of knots. We show that certain limit is zero as predicted by the volume conjecture.

I. Sahin

We find 95% confidence level limits on the anomalous coupling parameters $a_0$, $a_c$ and $a_n$ with an integrated luminosity of $500fb^{-1}$ and $\sqrt s =0.5, 1$ and 1.5 TeV energies. We take into account incoming beam polarizations and also the final state polarizations of the gauge bosons in the cross-section calculations to improve the bounds. We show t

M. Evans, S. Ballmer, M. Fejer, P. Fritschel

Thermal fluctuations in the coatings used to make high-reflectors are becoming significant noise sources in precision optical measurements and are particularly relevant to advanced gravitational wave detectors. There are two recognized sources of coating thermal noise, mechanical loss and thermal dissipation. Thermal dissipation causes thermal fluctuations i

Takenobu Nakamura, Akira Yoshimori

We derive the fluctuating hydrodynamic equation for the number and momentum densities exactly from the underdamped Langevin equation. This derivation is an extension of the Kawasaki-Dean formula in underdamped case. The steady state probability distribution of the number and momentum densities field can be expressed by the kinetic and potential energies. In

S. J. Curran, B. S. Koribalski, I. Bains

We have used the ATCA and the SEST to map the large-scale atomic and molecular gas in the nearby Circinus galaxy. The HI mosaic of Circinus exhibits the warps in position angle and inclination revealed in the single-pointing image, both of which appear to settle beyond the inner 30 kpc which was previously imaged. The molecular gas has been mapped in both th

Aitziber L. Cortajarena, Gregg Lois, Eilon Sherman, Corey S. O'Hern

Unfolded proteins may contain native or non-native residual structure, which has important implications for the thermodynamics and kinetics of folding as well as for misfolding and aggregation diseases. However, it has been universally accepted that residual structure should not affect the global size scaling of the denatured chain, which obeys the statistic

The BABAR Collaboration, B. Aubert

We present a measurement of the branching fraction of neutral B meson decaying to final states containing a K_1 meson, i.e. K_1(1270) and K_1(1400), and a charged pion. The data, collected with the BaBar detector at the Stanford Linear Accelerator Center, represent 454 million BBbar pairs produced in e+e- annihilation. We measure the branching fraction BF(B0

Patrick Hayden, Andreas Winter

For all p > 1, we demonstrate the existence of quantum channels with non-multiplicative maximal output p-norms. Equivalently, for all p >1, the minimum output Renyi entropy of order p of a quantum channel is not additive. The violations found are large; in all cases, the minimum output Renyi entropy of order p for a product channel need not be significantly

Igor Teper, Geert Vrijsen, Jongmin Lee, Mark A. Kasevich

We use a quantum nondemolition measurement to probe the collective pseudospin of an atomic ensemble in a high-finesse optical cavity. We analyze the backaction antisqueezing produced by the measurement process to show that our protocol could create conditional spin squeezing in the atomic ensemble.

Marta L. Guerra, M. A. Novotny, Hiroshi Watanabe, Nobuyasu Ito

We calculate the efficiency of a rejection-free dynamic Monte Carlo method for $d$-dimensional off-lattice homogeneous particles interacting through a repulsive power-law potential $r^{-p}$. Theoretically we find the algorithmic efficiency in the limit of low temperatures and/or high densities is asymptotically proportional to $ρ^{\tfrac{p+2}{2}}T^{-\tfrac{d

Estelle Basor, Yang Chen

In this paper we study the characteristic or generating function of a certain discontinuous linear statistics of the Laguerre unitary ensembles and show that this is a particular fifth Painléve transcendant in the variable $t,$ the position of the discontinuity. The proof of the ladder operators adapted to orthogonal polynomial with discontinuous weight anno

V. Prasad, Eric R. Weeks

We follow the diffusive motion of colloidal particles of diameter $d$ in soap films of varying thickness $h$ with fluorescence microscopy. Diffusion constants are obtained both from one- and two-particle microrheological measurements of particle motion in these films. These diffusion constants are related to the surface viscosity of the interfaces comprising

Eugene V. Koonin, Artem S. Novozhilov

The genetic code is nearly universal, and the arrangement of the codons in the standard codon table is highly non-random. The three main concepts on origin and evolution of the code are the stereochemical theory; the coevolution theory; and the error minimization theory. These theories are not mutually exclusive and are also compatible with the frozen accide

Efrain J. Ferrer, Vivian de la Incera

It is shown that in non-perturbative massless QED an anomalous magnetic moment is dynamically induced by an applied magnetic field. The induced magnetic moment produces a Zeeman splitting for electrons in Landau levels higher than $l=0$. The expressions for the non-perturbative Lande g-factor and Bohr magneton are obtained. Possible applications of this effe

Micah Lundberg, Kapilanjan Krishan, Ning Xu, Corey O'Hern

A fundamental difference between fluids and solids is their response to applied shear. Solids possess static shear moduli, while fluids do not. Complex fluids such as foams display an intermediate response to shear with nontrivial frequency-dependent shear moduli. In this manuscript, we conduct coordinated experiments and numerical simulations of model foams

Martin Hallnäs

A multivariable generalisation of the Bessel polynomials is introduced and studied. In particular, we deduce their series expansion in Jack polynomials, a limit transition from multivariable Jacobi polynomials, a sequence of algebraically independent eigenoperators, Pieri type recurrence relations, and certain orthogonality properties. We also show that thes

Jean Jacod, Emmanuel Kowalski, Ashkan Nikeghbali

We introduce a new type of convergence in probability theory, which we call ``mod-Gaussian convergence''. It is directly inspired by theorems and conjectures, in random matrix theory and number theory, concerning moments of values of characteristic polynomials or zeta functions. We study this type of convergence in detail in the framework of infinite

T. D. Browning, U. Derenthal

The Manin conjecture is established for a split singular cubic surface in P^3, with singularity type D_5.

Michael Zwolak

Understanding dissipative and decohering processes is fundamental to the study of quantum systems. An accurate and generic method for investigating these processes is to simulate both the system and environment, which, however, is computationally very demanding. We develop a novel approach to constructing finite representations of the environment based on th

Charles Frances, Karin Melnick

We study conformal actions of connected nilpotent Lie groups on compact pseudo-Riemannian manifolds. We prove that if a type-(p,q) compact manifold M supports a conformal action of a connected nilpotent group H, then the degree of nilpotence of H is at most 2p+1, assuming p <= q; further, if this maximal degree is attained, then M is conformally equivalent t

Megumi Harada, Graeme Wilkin

The results of this paper concern the Morse theory of the norm-square of the moment map on the space of representations of a quiver. We show that the gradient flow of this function converges, and that the Morse stratification induced by the gradient flow co-incides with the Harder-Narasimhan stratification from algebraic geometry. Moreover, the limit of the

C. Evoli, D. Gaggero, D. Grasso, L. Maccione

We model the transport of cosmic ray nuclei in the Galaxy by means of a new numerical code. Differently from previous numerical models we account for a generic spatial distribution of the diffusion coefficient. We found that in the case of radially uniform diffusion, the main secondary/primary ratios (B/C, N/O and sub-Fe/Fe) and the modulated antiproton spec

Adrian L. Melott

Time series analysis of fossil biodiversity of marine invertebrates in the Paleobiology Database (PBDB) shows a significant periodicity at approximately 63 My, in agreement with previous analyses based on the Sepkoski database. I discuss how this result did not appear in a previous analysis of the PBDB. The existence of the 63 My periodicity, despite very di

Ehud Fuchs, Michael Kroyter

In this work we review Schnabl&#39;s construction of the tachyon vacuum solution to bosonic covariant open string field theory and the results that followed. We survey the state of the art of string field theory research preceding this construction focusing on Sen&#39;s conjectures and the results obtained using level truncation methods. The tachyon vacuum s

Davide Gaiotto, Gregory W. Moore, Andrew Neitzke

We give a physical explanation of the Kontsevich-Soibelman wall-crossing formula for the BPS spectrum in Seiberg-Witten theories. In the process we give an exact description of the BPS instanton corrections to the hyperkahler metric of the moduli space of the theory on R^3 x S^1. The wall-crossing formula reduces to the statement that this metric is continuo

Hajime Yoshino, Tomoaki Nogawa, Bongsoo Kim

We demonstrate that a highly frustrated anisotropic Josephson junction array(JJA) on a square lattice exhibits a zero-temperature jamming transition, which shares much in common with those in granular systems. Anisotropy of the Josephson couplings along the horizontal and vertical directions plays roles similar to normal load or density in granular systems.

Paul H. Frampton, Thomas W. Kephart, Shinya Matsuzaki

In a simplified renormalizable model where the neutrinos have PMNS (Pontecorvo-Maki-Nakagawa-Sakata) mixings tan$^{2} θ_{12} = {1/2}, θ_{13}=0, θ_{23} = π/4$ and with flavor symmetry $T^{&#39;}$ there is a corresponding prediction where the quarks have CKM (Cabibbo-Kobayashi-Maskawa) mixings tan$2 Θ_{12} = \frac{\sqrt{2}}{3}, Θ_{13}=0, Θ_{23} =0$.

Madeleine L. Cule, Lutz Duembgen

In this note we provide explicit expressions and expansions for a special function which appears in nonparametric estimation of log-densities. This function returns the integral of a log-linear function on a simplex of arbitrary dimension. In particular it is used in the R-package &#34;LogCondDEAD&#34; by Cule et al. (2007).

Marc Culler, Jason DeBlois, Peter B. Shalen

We show that if M is a complete, finite-volume, hyperbolic 3-manifold having exactly one cusp, and if H_1(M;Z_2) has dimension at least 6, then M has volume greater than 5.06. We also show that if M is a closed, orientable hyperbolic 3-manifold such that H_1(M;Z_2) has dimension at least 4, and if the image of the cup product map in H^2(M;Z_2) has dimension

Lauren M. Childs, Steven H. Strogatz

We analyze the periodically forced Kuramoto model. This system consists of an infinite population of phase oscillators with random intrinsic frequencies, global sinusoidal coupling, and external sinusoidal forcing. It represents an idealization of many phenomena in physics, chemistry and biology in which mutual synchronization competes with forced synchroniz

Hy Trac, Renyue Cen, Abraham Loeb

We study the impact of inhomogeneous hydrogen reionization on the thermal evolution of the intergalactic medium (IGM) using hydrodynamic + radiative transfer simulations where reionization is completed either early (z ~ 9) or late (z ~ 6). In general, we find that low-density gas near large-scale overdensities is ionized and heated earlier than gas in the la

Peyman Eslami, Pawel Gora

In this paper we show that the piecewise linear map f(x) = px for x in [0,1/p], and sx-s/p for x in (1/p,1], p > 1, 0 < s < 1 which has an expanding, onto branch and a contracting branch is eventually piecewise expanding and exact.

J. B. Gutowski, W. A. Sabra

Half-supersymmetric geometries of N=2 five-dimensional gauged supergravity have recently been fully classified using spinorial geometry techniques. We use this classification to determine all possible regular half-supersymmetric near-horizon geometries, assuming that all of the gauge-invariant spinor bilinears are regular at the horizon. Four geometries are

Meera M. Parish, Jiangping Hu, B. Andrei Bernevig

The experimental consequences of different order parameters in iron-based superconductors are theoretically analyzed. We consider both nodeless and nodal order parameters, with an emphasis on the $\cos(k_x)\cdot \cos(k_y)$ nodeless order parameter recently derived by two of us. We analyze the effect of this order parameter on the spectral function, density o

Roman Sverdlov

In this paper we will define a Lagrangian for scalar and gauge fields on causal sets, based on the selection of an Alexandrov set in which the variations of appropriate expressions in terms of either the scalar field or the gauge field holonomies around suitable loops take on the least value. For these fields, we will find that the values of the variations o

Hideto Asashiba

Let $G$ be a group acting on a category $\mathcal{C}$. We give a definition for a functor $F\colon \mathcal{C} \to \mathcal{C}&#39;$ to be a $G$-covering and three constructions of the orbit category $\mathcal{C}/G$, which generalizes the notion of a Galois covering of locally finite-dimensional categories with group $G$ whose action on $\mathcal{C}$ is free

Boaz Keren-Zur, Luca Mazzucato, Yaron Oz

We analyze an R-symmetry breaking deformation of the ISS model for a direct mediation of supersymmetry breaking from a metastable vacuum. The model is weakly coupled and calculable. The LSP gravitino is light (m_{3/2}<16 eV) and the MSSM spectrum is natural with a light Higgs. The supersymmetry breaking sector, which is usually hidden, is observable (m~1 TeV

Danny Calegari, Dongping Zhuang

Let G be a finitely presented group, and G&#39; its commutator subgroup. Let C be the Cayley graph of G&#39; with all commutators in G as generators. Then C is large scale simply connected. Furthermore, if G is a torsion-free nonelementary word-hyperbolic group, C is one-ended. Hence (in this case), the asymptotic dimension of C is at least 2.

Gaston Giribet, Matthew Kleban, Massimo Porrati

A recent paper [arXiv:0801.4566] claims that topologically massive gravity contains only chiral boundary excitations at a particular value of the Chern-Simons coupling. On the other hand, propagating bulk degrees of freedom were found even at the chiral point in [arXiv:0803.3998]. The two references use very different methods, making comparison of their resp

Takamitsu Tanaka, Zoltán Haiman

The supermassive black holes (SMBHs) massive enough to power the bright redshift ~6 quasars observed in the Sloan Digital Sky Survey (SDSS) are thought to have assembled by mergers and/or gas accretion from less massive &#34;seed&#34; BHs. If the seeds are the ~100 Msol remnant BHs from the first generation of stars, they must be in place well before redshif

Jean-Christophe Breton, Clément Dombry

We consider weighted random balls in $\real^d$ distributed according to a random Poisson measure with heavy-tailed intensity and study the asymptotic behaviour of the total weight of some configurations in $\real^d$. This procedure amounts to be very rich and several regimes appear in the limit, depending on the intensity of the balls, the zooming factor, th

Zoltán Haiman, Bence Kocsis, Kristen Menou

Supermassive black hole binaries (SMBHBs) produced in galaxy mergers are thought to complete their coalescence, below separations of r_GW=10^{-3} (M_BH/10^8 M_sun)^{3/4} pc, as their orbit decays due to the emission of gravitational waves (GWs). It may be possible to identify such GW-driven inspirals statistically in an electromagnetic (EM) survey for variab

Alexandre Kosyak

We give the criterion for the irreducibility, the Schur irreducibility and the indecomposability of the set of two $n\times n$ matrices $Λ_n$ and $A_n$ in terms of the subalgebra associated with the &#34;support&#34; of the matrix $A_n$, where $Λ_n$ is a diagonal matrix with different non zeros eigenvalues and $A_n$ is an arbitrary one. The list of all maxim

Kentaro Kitagawa, Naoyuki Katayama, Kenya Ohgushi, Makoto Yoshida

We report results of 75As nuclear magnetic resonance (NMR) experiments on a self-flux grown single crystal of BaFe2As2. A first-order antiferromagnetic (AF) transition near 135 K was detected by the splitting of NMR lines, which is accompanied by simultaneous structural transition as evidenced by a sudden large change of the electric field gradient tensor at

Rafael Sánchez, Gloria Platero, Tobias Brandes

We study the counting statistics for electrons and photons being emitted from a driven two level quantum dot. Our technique allows us to calculate their mutual correlations as well. We study different transport configurations by tuning the chemical potential of one of the leads to find that the electronic and photonic fluctuations can be externally manipulat

Nils-Peter Skoruppa

It is proved that the theta series of an even lattice whose level is a power of a prime $\ell$ is congruent modulo $\ell$ to an elliptic modular form of level~1. The proof uses arithmetic and algebraic properties of lattices rather than methods from the theory of modular forms. The methods presented here may therefore be especially pleasing to those working

Anatolii A. Puhalskii

The focus of this paper is on the asymptotics of large-time numbers of customers in time-periodic Markovian many-server queues with customer abandonment in heavy traffic. Limit theorems are obtained for the periodic number-of-customers processes under the fluid and diffusion scalings. Other results concern limits for general time-dependent queues and for tim

Alexander Kusenko, Anupam Mazumdar

A generic consequence of supersymmetry is formation of a scalar condensate along the flat directions of the potential at the end of cosmological inflation. This condensate is usually unstable, and it can fragment into non-topological solitons, Q-balls. The gravitational waves produced by the fragmentation can be detected by Laser Interferometer Space Antenna

Stephen P. Jordan, Pawel Wocjan

The Jones and HOMFLY polynomials are link invariants with close connections to quantum computing. It was recently shown that finding a certain approximation to the Jones polynomial of the trace closure of a braid at the fifth root of unity is a complete problem for the one clean qubit complexity class. This is the class of problems solvable in polynomial tim

Chethan Krishnan

I consider semi-classical type IIA strings rotating in the AdS4 part of AdS4 X CP3. The one loop sigma model corrections to this classical solution are used to compute the energy shift, and the result is found to be E-S=f(lambda) ln S with f(lambda)= sqrt{2 lambda} - 5 ln 2 /2 pi + O (1/sqrt{lambda}). Even though the functional forms match, the actual numeri

Nikolay H. Balov

We introduce and study covariance fields of distributions on a Riemannian manifold. At each point on the manifold, covariance is defined to be a symmetric and positive definite (2,0)-tensor. Its product with the metric tensor specifies a linear operator on the respected tangent space. Collectively, these operators form a covariance operator field. We show th

T. K. Mandal, C. Felser, M. Greenblatt, J. Kubler

First principles electronic structure calculations have been carried out on ordered double perovskites Sr_2B&#39;B&#34;O_6 (for B&#39; = Cr or Fe and B&#34; 4d and 5d transition metal elements) with increasing number of valence electrons at the B-sites, and on Ba_2MnReO_6 as well as Ba_2FeMoO_6. The Curie temperatures are estimated ab initio from the electro

Marius Ionescu, Dana P. Williams

The generalized Effros-Hahn conjecture for groupoid C*-algebras says that, if G is amenable, then every primitive ideal of the groupoid C*-algebra C*(G) is induced from a stability group. We prove that the conjecture is valid for all second countable amenable locally compact Hausdorff groupoids. Our results are a sharpening of previous work of Jean Renault a

Sergio Miguel

Each cognitive science tries to understand a set of cognitive behaviors. The structuring of knowledge of this nature&#39;s aspect is far from what it can be expected about a science. Until now universal standard consistently describing the set of cognitive behaviors has not been found, and there are many questions about the cognitive behaviors for which only

Sean Yeager, Larry Zamick

We define the ``quadrupole ratio&#39;&#39; $r_Q = \dfrac{Q_0(S)}{Q_0(B)}$ where $Q_0(S)$ is the intrinsic quadrupole moment obtained from the static quadrupole moment of the $2_1^+$ state of an even-even nucleus and $Q_0(B)$ the intrinsic quadrupole moment obtained from $B(E2)_{0 \to 2}$. In both cases we assume a simple rotational formula connecting the rot

A. Stein, H. Knöckel, E. Tiemann

Precise potentials for the ground state X1Sigma+g and the minimum region of the excited state 2_1Sigma+u of Sr2 are derived by high resolution Fourier-transform spectroscopy of fluorescence progressions from single frequency laser excitation of Sr2 produced in a heat pipe at 950 Celsius. A change of the rotational assignment by four units compared to an earl

C. Girardot, J. Kreisel, S. Pignard, N. Caillault

We report a temperature-dependent Raman scattering investigation of thin film rare earth nickelates SmNiO3, NdNiO3 and Sm0.60Nd0.40NiO3, which present a metal-to-insulator (MI) transition at TMI and an antiferromagnetic-paramagnetic Neel transition at TN. Our results provide evidence that all investigated samples present a structural phase transition at TMI

Joost de Graaf, Jos Zwanikken, Markus Bier, Arjen Baarsma

We study the spontaneous charging and the crystallization of spherical micron-sized water-droplets dispersed in oil by numerically solving, within a Poisson-Boltzmann theory in the geometry of a spherical cell, for the density profiles of the cations and anions in the system. We take into account screening, ionic Born self-energy differences between oil and

Dieter Lust, Fernando Marchesano, Luca Martucci, Dimitrios Tsimpis

We discuss a novel strategy to construct 4D N=0 stable flux vacua of type II string theory, based on the existence of BPS bounds for probe D-branes in some of these backgrounds. In particular, we consider compactifications where D-branes filling the 4D space-time obey the same BPS bound as they would in an N=1 compactification, while other D-branes, like tho

N. Baro, F. Boudjema, A. Semenov

We give an extensive description of the renormalisation of the Higgs sector of the minimal supersymmetric model in SloopS. SloopS is an automatised code for the computation of one-loop processes in the MSSM. In this paper, the first in a series, we study in detail the non gauge invariance of some definitions of tan(beta). We rely on a general non-linear gaug

Athanasios Dedes, Terrance Figy, Stefan Hoche, Frank Krauss

Phenomenological implications of a minimal extension to the Standard Model are considered, in which a Nambu-Goldstone boson emerges from the spontaneous breaking of a global U(1) symmetry. This is felt only by a scalar field which is a singlet under all Standard Model symmetries, and possibly by neutrinos. Mixing between the Standard Model Higgs boson field

Ladislav Samaj, Bernard Jancovici

This study is related to the fluctuation theory of electromagnetic fields, charges and currents. The three-dimensional system under consideration is a semi-infinite conductor, modeled by the jellium, in vacuum. In previous theoretical studies it was found that the correlation functions of the surface charge density on the conductor decay as the inverse cube

Sean Sather-Wagstaff, Siamak Yassemi

We prove versions of results of Foxby and Holm about modules of finite (Gorenstein) injective dimension and finite (Gorenstein) projective dimension with respect to a semidualizing module. We also verify special cases of a question of Takahashi and White.

G. Finocchio, O. Ozatay, L. Torres, R. A. Buhrman

We study, both experimentally and by numerical modeling, the magnetic dynamics that can be excited in a magnetic thin-film nanopillar device using the spin torque from a spatially localized current injected via a 10s-of-nm-diameter aperture. The current-driven magnetic dynamics can produce large amplitude microwave emission at zero magnetic field, with a fre

Jeremy Schiff, Yair Goldfarb, David J. Tannor

Path integral derivations are presented for two recently developed complex trajectory techniques for the propagation of wave packets, Complex WKB and BOMCA. Complex WKB is derived using a standard saddle point approximation of the path integral, but taking into account the hbar dependence of both the amplitude and the phase of the intial wave function, thus

CDF Collaboration, T. Aaltonen

We report a measurement of the top quark mass $M_t$ in the dilepton decay channel $t\bar{t}\to b\ell&#39;^{+}ν&#39;_\ell\bar{b}\ell^{-}\barν_{\ell}$. Events are selected with a neural network which has been directly optimized for statistical precision in top quark mass using neuroevolution, a technique modeled on biological evolution. The top quark mass is e

Christiane Quesne

On using the known equivalence between the presence of a position-dependent mass (PDM) in the Schrödinger equation and a deformation of the canonical commutation relations, a method based on deformed shape invariance has recently been devised for generating pairs of potential and PDM for which the Schrödinger equation is exactly solvable. This approach has p

Florian Berger, Tim Schmiedl, Udo Seifert

In a spatially periodic temperature profile, directed transport of an overdamped Brownian particle can be induced along a periodic potential. With a load force applied to the particle, this setup can perform as a heat engine. For a given load, the optimal potential maximizes the current and thus the power output of the heat engine. We calculate the optimal p

Virginia L. Corless, Lindsay J. King

Measuring the 3D distribution of mass on galaxy cluster scales is a crucial test of the LCDM model, providing constraints on the behaviour of dark matter. Recent work investigating mass distributions of individual galaxy clusters (e.g. Abell 1689) using weak and strong gravitational lensing has revealed potential inconsistencies between the predictions of st

Gao-Feng Gu, Wei-Xing Zhou

The Mike-Farmer (MF) model was constructed empirically based on the continuous double auction mechanism in an order-driven market, which can successfully reproduce the cubic law of returns and the diffusive behavior of stock prices at the transaction level. However, the volatility (defined by absolute return) in the MF model does not show sound long memory.

Satoshi Ishizaka, Tohya Hiroshima

We consider a scheme of quantum teleportation where a receiver has multiple (N) output ports and obtains the teleported state by merely selecting one of the N ports according to the outcome of the sender&#39;s measurement. We demonstrate that such teleportation is possible by showing an explicit protocol where N pairs of maximally entangled qubits are employ

C. Fechner, P. Richter

We present a study of NV absorption systems at 1.5 < z < 2.5 in the optical spectra of 19 QSOs. Our analysis includes both absorbers arising from the intergalactic medium as well as systems in the vicinity of the background quasar. We construct detailed photoionization models to study the physical conditions and abundances in the absorbers and to constrain t

C. J. Walcher, F. Lamareille, D. Vergani, S. Arnouts

We intend to show that it is possible to derive the physical parameters of galaxies from their broad-band spectral energy distribution out to a redshift of 1.2. This method has the potential to yield the physical parameters of all galaxies in a single field in a homogeneous way. We use an extensive dataset, assembled in the context of the VVDS survey, which

Sperello di Serego Alighieri, Jaron Kurk, Benedetta Ciardi, Andrea Cimatti

Population III stars, the first generation of stars formed from primordial Big Bang material with a top-heavy IMF, should contribute substantially to the Universe reionization and they are crucial for understanding the early metal enrichment of galaxies. Therefore it is very important that these objects, foreseen by theories, are detected by observations. Ho

S. Tsuneta, K. Ichimoto, Y. Katsukawa, B. W. Lites

We present the magnetic landscape of the polar region of the Sun that is unprecedented in terms of high spatial resolution, large field of view, and polarimetric precision. These observations were carried out with the Solar Optical Telescope aboard \emph{Hinode}. Using a Milne-Eddington inversion, we found many vertically-oriented magnetic flux tubes with fi

Roumen Tsekov

A comment on the recent paper of R Manica, J N Connor, L Y Clasohm, S L Carnie, R G Horn, D Y C Chan, Transient response of a wetting film to mechanical and electrical perturbations, Langmuir 2008, 24, 1381.

R. Kenna, J. J. Ruiz-Lorenzo

A combination of recent numerical and theoretical advances are applied to analyze the scaling behaviour of the site-diluted Ising model in two dimensions, paying special attention to the implications for multiplicative logarithmic corrections. The analysis focuses primarily on the odd sector of the model (i.e., that associated with magnetic exponents), and i

A. D. Jackson, G. M. Kavoulakis, M. Magiropoulos

A Bose-Einstein condensate produced by a Hamiltonian which is rotationally or translationally symmetric is fragmented as a direct result of these symmetries. A corresponding mean-field unfragmented state, with an identical energy to leading order in the number of particles, can generally be constructed. As a consequence, vanishingly weak symmetry-breaking pe

Subhash Khot, Assaf Naor

In the kernel clustering problem we are given a large $n\times n$ positive semi-definite matrix $A=(a_{ij})$ with $\sum_{i,j=1}^na_{ij}=0$ and a small $k\times k$ positive semi-definite matrix $B=(b_{ij})$. The goal is to find a partition $S_1,...,S_k$ of $\{1,... n\}$ which maximizes the quantity $$ \sum_{i,j=1}^k (\sum_{(i,j)\in S_i\times S_j}a_{ij})b_{ij}

Hajime Ishimori, Tatsuo Kobayashi, Yuji Omura, Morimitsu Tanimoto

We study the supersymmetric model with the A4 lepton flavor symmetry, in particular soft supersymmetry breaking terms, which are predicted from the A4 lepton flavor symmetry. We evaluate soft slepton masses and A-terms within the framework of supergravity theory. Constraints due to experiments of flavor changing neutral current processes are examined.

K. A. Bugaev

Here I discuss the major pitfalls and the most severe mistakes of the above mentioned paper. The thorough analysis shows that despite all the claims the present work has nothing to do with the thermalization process in relativistic heavy ion collisions. In contrast to the authors&#39; beliefs I show that their main result is not derived, but is a combination

Anthony Meilland, Florentin Millour, Philippe Stee, Alain Spang

We study the Be star $δ$ Cen circumstellar disk using long-baseline interferometry which is the only observing technique capable of resolving spatially and spectroscopically objects smaller than 5 mas in the H and K b and. We used the VLTI/AMBER instrument on January 6, 8, and 9, 2008, in the H and K bands to complete low (35) and medium (150 0) spectral res

D. Ihle, M. Pfafferott, E. Burovski, F. X. Bronold

Motivated by the possibility of pressure-induced exciton condensation in intermediate-valence Tm[Se,Te] compounds we study the Falicov-Kimball model extended by a finite f-hole valence bandwidth. Calculating the Frenkel-type exciton propagator we obtain excitonic bound states above a characteristic value of the local interband Coulomb attraction. Depending o

L. D. Ferramacho, A. Blanchard, Y. Zolnierowski

We examine the constraints that can be obtained on standard cold dark matter models from the most currently used data set: CMB anisotropies, type Ia supernovae and the SDSS luminous red galaxies. We also examine how these constraints are widened when the equation of state parameter $w$ and the curvature parameter $Ω_k$ are left as free parameters. For the $Λ

Stephan André, Valentina Brosco, Alexander Shnirman, Gerd Schön

Motivated by recent experiments, which demonstrated lasing and cooling of the electromagnetic field in an electrical resonator coupled to a superconducting qubit, we study the phase coherence and diffusion of the system in the lasing state. We also discuss phase locking and synchronization induced by an additional {\sl ac} driving of the resonator. We extend

Han-Yong Choi, Yunkyu Bang

We present the self-consistent Bogoliubov-de Gennes calculations of an $sπ$ pairing state of two band superconductivity as a model for the FeAs superconductors. The $sπ$ state is an s-wave pairing state with an internal $π$ phase, that is, nodeless gaps on each band but with the opposite sign. The novel features of this state are investigated by calculating

M. Hossain Ali, M. Atiqur Rahman

We investigate transverse electromagnetic waves propagating in a plasma influenced by the gravitational field of the Schwarzschild-de Sitter black hole. Applying 3+1 spacetime split we derive the relativistic two-fluid equations to take account of gravitational effects due to the event horizon and describe the set of simultaneous linear equations for the per

Shi Qi, Fa-Yin Wang, Tan Lu

We explore the gamma-ray bursts&#39; (GRBs&#39;) contributions in constraining the dark energy equation of state (EOS) at high ($1.8 < z < 7$) and at middle redshifts ($0.5 < z < 1.8$) and estimate how many GRBs are needed to get substantial constraints at high redshifts. We estimate the constraints with mock GRBs and mock type Ia supernovae (SNe Ia) for com

Zhi-Gang Wang

In this article, we assume that there exists a scalar hidden charm tetraquark state in the $π^+ χ_{c1}$ invariant mass distribution, and study its mass using the QCD sum rules. The numerical result $M_{Z}=(4.36\pm0.18) \rm{GeV}$ is consistent with the mass of the Z(4250). The Z(4250) may be a tetraquark state, other possibilities, such as a hadro-charmonium

S. Basilakos, M. Plionis

We study the global dynamics of the universe within the framework of the Interacting Dark Matter (IDM) scenario. Assuming that the dark matter obeys the collisional Boltzmann equation, we can derive analytical solutions of the global density evolution, which can accommodate an accelerated expansion, equivalent to either the {\em quintessence} or the standard