January 2005 arXiv papers — page 16

Alka Upadhyay, J. P. Singh

Gluonic contributions to the self-energy of a nucleon have been investigated in an effective theory. The couplings of the topological charge density to nucleons give rise to OZI violating nucleon interactions. The one-loop self-energy of a nucleon arising due to these interactions have been calculated using a heavy baryon chiral perturbation theory. The dive

Soushi Tsuno

We have developed an extended framework, named GR@PPA, of the GRACE system for hadron collisions. The GRACE system is an automatic Feynman diagram calculation system and an event generator based on this diagram calculation. While the original GRACE system assumes that both the initial and final states are well-defined, the GR@PPA framework applies that the i

Xiao-Gang He

In this talk I review some topics related to flavor physics in kaon decays with emphasis on the roles which kaon decays can play in the determinations of hadronic matrix elements, the CKM parameters and new physics beyond the Standard Model.

Antonio Masiero, Stefano Profumo, Piero Ullio

We study the phenomenology of neutralino dark matter within generic supersymmetric scenarios where the Gaugino and Higgsino masses are much lighter than the scalar soft breaking masses (Split Supersymmetry). We consider a low-energy model-independent approach and show that the guidelines in the definition of this general framework come from cosmology, which

L. Litov

The new results of investigation of K^0_Le3 and K^{\pm}e3 decays performed by NA48 Collaboration are presented. The measured branching fractions are used to extract Vus. The values of Ke3 form-factors and radiative K^0_Le3γbranching ratio are reported. A list of recent NA48 results concerning some rare neutral kaon decays is given.

Orfeu Bertolami

A model for noncommutative scalar fields coupled to gravity based on the generalization of the Moyal product is proposed. Solutions compatible with homogeneous and isotropic flat Robertson-Walker spaces to first non-trivial order in the perturbation of the star-product are presented. It is shown that in the context of a typical chaotic inflationary scenario,

Sergiu I. Vacaru

We construct a new class of exact solutions describing spacetimes possessing Lie algebroid symmetry. They are described by generic off-diagaonal 5D metrics embedded in bosonic string gravity and possess nontrivial limits to the Einstein gravity. While we focus on nonholonomic vielbein transforms of the Schwarzschild metrics to 5D ansatz with solitonic backgr

S. N. Andrianov, V. V. Bochkarev

Brane model of universe is considered for zero-mass particle. Equation of Wheeler - de Witt type is obtained using variation principle from the well-known conservation laws inside the brane. This equation includes term accounting the variation of brane topology. Solutions are obtained analytically at some simplifications and the dispersion relations are deri

Pierre-Louis Curien

This paper is the second part of an introduction to linear logic and ludics, both due to Girard. It is devoted to proof nets, in the limited, yet central, framework of multiplicative linear logic and to ludics, which has been recently developped in an aim of further unveiling the fundamental interactive nature of computation and logic. We hope to offer a few

D. J. Capelis

Over the recent months it has become clear that the current generation of cryptographic hashing algorithms are insufficient to meet future needs. The ASH family of algorithms provides modifications to the existing SHA-2 family. These modifications are designed with two main goals: 1) Providing increased collision resistance. 2) Increasing mitigation of secur

Sophia E. Economou, Ren-Bao Liu, L. J. Sham, D. G. Steel

In a $Λ$ system with two nearly degenerate ground states and one excited state in an atom or quantum dot, spontaneous radiative decay can lead to a range of phenomena, including electron-photon entanglement, spontaneously generated coherence, and two-pathway decay. We show that a treatment of the radiative decay as a quantum evolution of a single physical sy

David J. Aldous

In the mean field (or random link) model there are $n$ points and inter-point distances are independent random variables. For $0 < \ell < \infty$ and in the $n \to \infty$ limit, let $δ(\ell) = 1/n \times$ (maximum number of steps in a path whose average step-length is $\leq \ell$). The function $δ(\ell)$ is analogous to the percolation function in percolati

O. V. Kibis, D. G. W. Parfitt, M. E. Portnoi

Electron motion in a (n,1) carbon nanotube is shown to correspond to a de Broglie wave propagating along a helical line on the nanotube wall. This helical motion leads to periodicity of the electron potential energy in the presence of an electric field normal to the nanotube axis. The period of this potential is proportional to the nanotube radius and is gre

Michael W. Jack, Makoto Yamashita

Starting with two weakly-coupled anti-ferromagnetic spinor condensates, we show that by changing the sign of the coefficient of the spin interaction, $U_{2}$, via an optically-induced Feshbach resonance one can create an entangled state consisting of two anti-correlated ferromagnetic condensates. This state is maximally entangled and a generalization of the

Michael W. Jack, Makoto Yamashita

We consider the Bose-Hubbard model of atoms in an optical lattice potential when the atom-atom interactions are attractive. If the lowest energy lattice sites are degenerate (such as in the homogeneous case), then, at a critical value of the interaction strength, a phase-coherent condensate becomes unstable to a quantum superposition such that the number dis

M. Herz, Ch. Schiller, F. J. Giessibl, J. Mannhart

The local work function of a surface determines the spatial decay of the charge density at the Fermi level normal to the surface. Here, we present a method that enables simultaneous measurements of local work function and tip-sample forces. A combined dynamic scanning tunneling microscope and atomic force microscope is used to measure the tunneling current b

Elmar Bittner, Wolfhard Janke

We employ Monte Carlo simulations to study a generalized three-dimensional complex $psi|^4 theory of Ginzburg-Landau form and compare our numerical results with a recent quasi-analytical mean-field type approximation, which predicts first-order phase transitions in parts of the phase diagram. As we have shown earlier, this approximation does not apply to the

R. R. Urbano, P. G. Pagliuso, C. Rettori, P. Schlottmann

The local environment of Eu$^{2+}$ ($4f^{7}$, $S=7/2$) in Ca$_{1-x}$Eu$_{x}$B$_{6}$ ($0.003\leqslant x\leqslant 1.00$) is investigated by means of electron spin resonance (ESR). For $x\lesssim 0.003$ the spectra show resolved \textit{fine} and \textit{hyperfine} structures due to the cubic crystal \textit{electric} field and nuclear \textit{hyperfine} field,

H. Won, S. Haas, D. Parker, S. Telang

This course has a dual purpose. First we review the successes of the weak-coupling BCS theory in describing new classes of superconductors discovered since 1979. They include the heavy-fermion superconductors, high-Tc cuprate superconductors, organic superconductors, Sr2RuO4, etc. Second, we present the quasiclassical approximation introduced by Volovik, whi

N. Marcano, J. I. Espeso, J. C. Gomez Sal, J. Rodriguez Fernandez

We present a detailed specific heat study of the CeNi$_{1-x}$Cu$_{x}$series in a large temperature range of 0.2 K to 300 K. The analysis of these data, considering also previous neutron scattering, magnetic characterization and $μ$SR results, allows us to present a convenient description of the system as inhomogeneous on the nanometric scale. Two regimes are

C. Cantoni, D. T. Verebelyi, E. D. Specht, J. Budai

The critical current density of epitaxial YBCO films grown on vicinal SrTiO3 substrates was investigated by electrical transport measurements along and across the steps of the SrTiO3 surface for a range of temperatures of 10 K to 85 K and in applied magnetic fields varying from 0 to 14 T. For vicinal angles of 4 and 8 degrees, we found evidence of enhanced p

M. E. Zhitomirsky

An effective spin-orbit Hamiltonian is derived for a spin-1/2 trimerized kagome antiferromagnet in the second-order of perturbation theory in the ratio of two coupling constants. Low-energy singlet states of the obtained model are mapped to a quantum dimer model on a triangular lattice. The quantum dimer model is dominated by dimer resonances on a few shorte

M. L. Della Rocca, M. Aprili, T. Kontos, A. Gomez

The ground state of highly damped PdNi based 0-pi ferromagnetic Josephson junctions shows a spontaneous half quantum vortex, sustained by a supercurrent of undetermined sign. This supercurrent flows in the electrode of a Josephson junction used as a detector and produces a phi(0)/4 shift in its magnetic diffraction pattern. We have measured the statistics of

R. Vikram Raj Pandya

A closed set of \textit{exact} equations describing statistical theory of turbulent self-diffusion by multivariate-normal turbulent velocity field is derived. In doing so, we first suggest exact formulas for correlations $<f_i(p)f_j(p&#39;)R[{\bf f}]>$, $<g(p)R[{\bf f}]>$ and $<g(p)f_j(p&#39;)R[{\bf f}]>$ when the functional $R[{\bf f}]$ is functional of fun

David R. Heine, Gary S. Grest, Edmund B. Webb

Molecular dynamics simulations are used to study the spreading of binary polymer nanodroplets in a cylindrical geometry. The polymers, described by the bead-spring model, spread on a flat surface with a surface-coupled Langevin thermostat to mimic the effects of a corrugated surface. Each droplet consists of chains of length 10 or 100 monomers with ~350,000

Mathilde Hugbart, Jocelyn Retter, Fabrice Gerbier, Andres Varon

We measure the spatial correlation function of Bose-Einstein condensates in the cross-over region between phase-coherent and strongly phase-fluctuating condensates. We observe the continuous path from a gaussian-like shape to an exponential-like shape characteristic of one-dimensional phase-fluctuations. The width of the spatial correlation function as a fun

Y. M. Galperin, D. V. Shantsev, J. Bergli, B. L. Altshuler

The problem of Rabi oscillations in a qubit coupled to a fluctuator and in contact with a heath bath is considered. A scheme is developed for taking into account both phase and energy relaxation in a phenomenological way, while taking full account of the quantum dynamics of the four-level system subject to a driving AC field. Significant suppression of the R

I. Felner, G. Kopnov, G. Koren

A dc magnetic study is reported on c-axis oriented epitaxial thin films of EuSr2Eu1.5Ce0.5Cu2O10 (Ru-1222) on (100) SrTiO3 wafers. Magnetic measurements on 200 and 500 nm thick films were performed with the magnetic field either parallel or perpendicular to the wafer. We found that the films order magnetically at 180 K. The easy axis of the magnetization is

S. Pal, M. K. Sanyal, Neena S. John, G. U. Kulkarni

Gold nanoclusters encapsulated with organic molecules are of great interest for its possible applications in the fields of molecular electronics, catalysis and medical science. Here we demonstrate that monolayer and bilayer films of thiol-capped gold nanoclusters can exhibit diode-like properties provided controlled spatial asymmetry exist between two tunnel

Gilberto Giugliarelli

The unbinding properties of an interface near structured wedges are investigated by discrete models with short range interactions. The calculations demonstrate that interface unbinding take place in two stages: $i$) a continuous filling--like transition in the pure wedge--like parts of the structure; $ii$) a conclusive discontinuous unbinding. In 2$D$ an exa

R. Nirmala, S. K. Malik, A. V. Morozkin, K. G. Suresh

A new ternary intermetallic compound, namely, YbMn2Sb2, has been synthesized and its magnetic and electrical transport properties have been studied in the temperature range of 2 to 300 K. This compound crystallizes in a trigonal, La2O2S type structure (space group P3bm1, No. 164) and is found to be ferromagnetically ordered at room temperature. The magnetism

G. V. Kurlyandskaya, S. M. Bhagat

During the past ten years nanostructures have been subject of active research. Fabrication of such systems follows well developed methods. The increase in the number of materials available for research and applications requires that the methods of their characterization be even more precise then before. Thin film structures have many advantages for technolog

M. H. Vainstein, I. V. L. Costa, F. A. Oliveira

Complex systems such as glasses, gels, granular materials, and systems far from equilibrium exhibit violation of the ergodic hypothesis (EH) and of the fluctuation-dissipation theorem (FDT). Recent investigations in systems with memory have established a hierarchical connection between mixing, the EH and the FDT. They have shown that a failure of the mixing

V. N. Kuzovkov, W. von Niessen

The method proposed by the present authors to deal analytically with the problem of Anderson localization via disorder [J.Phys.: Condens. Matter {\bf 14} (2002) 13777] is generalized for higher spatial dimensions D. In this way the generalized Lyapunov exponents for diagonal correlators of the wave function, $<ψ^2_{n,\mathbf{m}}>$, can be calculated analytic

Michael J. Kearney, Satya N. Majumdar

The area swept out under a one-dimensional Brownian motion till its first-passage time is analysed using a backward Fokker-Planck technique. We obtain an exact expression of the area distribution for the zero drift case, and provide various asymptotic results for the non-zero drift case, emphasising the critical nature of the behaviour in the limit of vanish

M. Bhattacharya, M. K. Sanyal, Th. Geue, U. Pietsch

Glass transition process gets affected in ultrathin films having thickness comparable to the size of the molecules. We observe systematic broadening of glass transition temperature (Tg) as the thickness of the polymer film reduces below the radius of gyration but the change in the average Tg was found to be very small. Existence of reversible negative and po

L. Samaj

We test the concepts of renormalized charge and potential saturation, introduced within the framework of highly asymmetric Coulomb mixtures, on exactly solvable Coulomb models. The object of study is the average electrostatic potential induced by a unique &#34;guest&#34; charge immersed in a classical electrolyte, the whole system being in thermal equilibriu

K. Sasaki, S. Murakami, R. Saito, Y. Kawazoe

It has been known theoretically that localized states exist around zigzag edges of a graphite ribbon and of a carbon nanotube, whose energy eigenvalues are located between conduction and valence bands. We found that in metallic single-walled zigzag carbon nanotubes two of the localized states become critical, and that their localization length is sensitive t

V. G. Veselago

The question is considered about possibility of overcoming diffraction limit at device, named superlens. This device is a flat slab, executed from material with index of refraction n,equal n=-1. It is shown, what this device really can focus the radiation to the spot, smaller than wavelength, but herewith superlens works not as optical instrument, based on t

Vincent I. Conrad, Andrew D. Greentree, David N. Jamieson, Lloyd C. L. Hollenberg

The single electron transistor (SET) offers unparalled opportunities as a nano-scale electrometer, capable of measuring sub-electron charge variations. SETs have been proposed for read-out schema in solid-state quantum computing where quantum information processing outcomes depend on the location of a single electron on nearby quantum dots. In this paper we

Guo-meng Zhao

Zhao et al. [Phys. Rev. B 62, R11 949 (2000)] reported studies of the oxygen-isotope effects on the intrinsic resistivity and thermoelectric power in the paramagnetic state of several ferromagnetic manganites. The isotope effects on the intrinsic electrical transport properties are not consistent with a simple small-polaron hopping mechanism, but can be well

Akihiro Tanaka, Xiao HU

We uncover new topology-related features of the $π$-flux saddle-point solution of the $D$=2+1 Heisenberg antiferromagnet. We note that symmetries of the spinons sustain a built-in competition between antiferromagnetic (AF) and valence-bond-solid (VBS) orders, the two tendencies central to recent developments on quantum criticality. An effective theory contai

Tom Savels, Allard P. Mosk, Ad Lagendijk

We provide analytic solutions of the optical Bloch equations for a two-level system interacting with a broadband light field. We will focus on two special examples: incident light with a Lorentzian spectral density and the limit of incident monochromatic light. The results are used to obtain an expression for the nonlinear polarizability of a two-level atom

Thorsten Koehler, Eite Tiesinga, Paul S. Julienne

We study the spontaneous dissociation of diatomic molecules produced in cold atomic gases via magnetically tunable Feshbach resonances. We provide a universal formula for the lifetime of these molecules that relates their decay to the scattering length and the loss rate constant for inelastic spin relaxation. Our universal treatment as well as our exact coup

A. O. Sousa

A Bounded Confidence (BC) model of socio-physics, in which the agents have continuous opinions and can influence each other only if the distance between their opinions is below a threshold, is simulated on a still growing scale-free network considering several different strategies: for each new node (or vertex), that is added to the network all individuals o

A. Aldea, M. Tolea, J. Zittartz

We investigate the properties of the electron spin-transmission through an Aharonov-Bohm interferometer with an embedded multilevel quantum dot containing magnetic impurities. A suitable formalism is developed. The amplitude and the phase of the flip- and nonflip-transmittance are calculated numerically as function of the magnetic field and the gate potentia

S. J. Weatherley, S. J. Warren, P. Moller, S. M. Fall

We present the detection of [OIII] emission lines from the galaxies responsible for two high-redshift z>1.75 damped Lyman-alpha (DLA) absorption lines. These are the first detections of rest-frame optical emission lines from high-redshift DLA galaxies. Unlike the Lyman-alpha line, the [OIII] line provides a measure of the systemic velocity of the galaxy. We

Travis S. Metcalfe

The interpretation of pulsation data for Sun-like stars is currently facing challenges quite similar to those faced by white dwarf modelers ten years ago. The observational requirements for uninterrupted long-term monitoring are beginning to be satisfied by successful multi-site campaigns and dedicated satellite missions. But exploration of the most importan

Frederic Thévenin, Pierre Kervella, Bernard Pichon, Pierre Morel

Using VLTI/VINCI angular diameter measurements, we constrain the evolutionary status of three asteroseismic targets: the stars $δ$ Eri, $ξ$ Hya, $η$ Boo. Our predictions of the mean large frequency spacing of these stars are in agreement with published observational estimations. Looking without success for a companion of $δ$ Eri we doubt on its classificatio

M. Lachieze-Rey, S. Caillerie

The possibility that our space is multi - rather than singly - connected has gained a renewed interest after the discovery of the low power for the first multipoles of the CMB by WMAP. To test the possibility that our space is a multi-connected spherical space, it is necessary to know the eigenmodes of such spaces. Excepted for lens and prism space, and in s

P. Moskalik, W. A. Dziembowski

We interpret the three periods detected in OGLE LMC Cepheids SC3-360128 and SC5-338399 as corresponding to the first three overtones of radial pulsations. This interpretation imposes stringent constraints on parameters of the stars and on their evolutionary status, which could only be the first crossing of the instability strip. Evolutionary models reproduci

J. Köppen, G. Hensler

The chemical evolution of galaxies that undergo an episode of massive and rapid accretion of metal-poor gas is investigated with models using both simplified and detailed nucleosynthesis recipes. The rapid decrease of the oxygen abundance during infall is followed by a slower evolution which leads back to the closed-box relation, thus forming a loop in the N

Montse Villar-Martin, Clive Tadhunter, Raffaella Morganti, Joanna Holt

We report the discovery of a giant (~160 kpc) knotty extended emission line nebula associated with the radio galaxy PKS1932-46 at z=0.23. The 2-d long slit spectra, obtained with VLT-FORS2 at a large angle (~63 degr) to the radio source axis, shows that the nebula extends well beyond the radio structure and the ionization cones of the active nucleus. This is

R. Bernabei, P. Belli, F. Cappella, R. Cerulli

The DAMA/NaI experiment (about 100 kg highly radiopure NaI(Tl)) was proposed, designed and realised to effectively investigate in a model independent way the presence of a Dark Matter particle component in the galactic halo by exploiting the annual modulation signature. With a total exposure of 107731 kg day, collected over seven annual cycles deep undergrou

E. S. Laird, K. Nandra, K. L. Adelberger, C. C. Steidel

We present an analysis of the X-ray emission from a large sample of ultraviolet (UV) selected, star forming galaxies with 0.74<z<1.32 in the Hubble Deep Field North (HDF-N) region. By excluding all sources with significant detected X-ray emission in the 2 Ms Chandra observation we are able to examine the properties of galaxies for which the emission in both

M. Bottaccio, M. Montuori, L. Pietronero

Precise analyses of the statistical and scaling properties of galaxy distribution are essential to elucidate the large-scale structure of the universe. Given the ongoing debate on its statistical features, the development of statistical tools permitting to discriminate accurately different spatial patterns is highly desiderable. This is specially the case wh

Clive Tadhunter

The advent of sensitive polarimeters on large telescopes has led to a revolution in our understanding of active galaxies over the last 20 years. In the case of powerful radio galaxies the deep polarimetric measurements made possible by the new technology have: (a) provided the most direct evidence to support the unified schemes for powerful radio galaxies; (

A. Rossetti, F. Mantovani, D. Dallacasa, C. Fanti

VLBA observations are presented for 6 compact radio sources selected from the Peacock & Wall catalogue. From the new morphological and spectral information 2 objects that in the Peacock and Wall catalogue are flat spectrum (alpha < 0.5) sources, appear to be double sided objects with linear sizes of the order of one kpc. Three are core-jet sources and the la

R. Sánchez-Janssen, J. Iglesias-Páramo, C. Muñoz-Tuñón, J. A. L. Aguerri

We present a wide field $V$-band imaging survey of approximately 1 deg$^2$ ($\sim7.2 h^{-2}_{75}$ Mpc$^{2}$) in the direction of the nearby cluster of galaxies Abell 2151 (the Hercules Cluster). The data are used to construct the luminosity function (LF) down to $M_V \approx -14.85$, thus allowing us to study the dwarf galaxy population in A2151 for the firs

O. Straniero, R. Gallino, S. Cristallo

The main component of the s process is produced by low mass stars (between 1.5 and 3 Mo), when they climb for the second time the red giant branch and experience a series of He shell flashes called thermal pulses. During the relatively long period (10^5 yr) that elapses between two subsequent thermal pulses, a slow neutron flux is provided by the 13C(a,n)16O

D. Fargion

Old and recent puzzles of GRBs and SGRs find a solution with a model based on the fast blazing of very collimated thin gamma Jets. Damped oscillating afterglows in GRB030329 find a natural explanation assuming a very thin Jet whose persistent activity and different angle of view maybe combined at once with the Supernovae power and the apparent huge GRBs outp

L. Zappacosta, R. Maiolino, A. Finoguenov, F. Mannucci

We have identified a large-scale structure traced by galaxies at z=0.8, within the Lockman Hole, by means of multi-object spectroscopic observations. By using deep XMM images we have investigated the soft X-ray emission from the Warm-Hot Intergalactic Medium (WHIM) expected to be associated with this large-scale structure and we set a tight upper limit to it

Leo Blitz

Starting with the assertion that the problem of isolated, single star formation is essentially solved, this paper examines some of the missing steps needed to go from there to understanding the star formation history of the Universe. Along the way, some results on the formation of star clusters in the Milky Way and the properties of GMCs in nearby galaxies a

Francesca Civano, Andrea Comastri, Marcella Brusa

We present the results of a detailed spectral analysis of optically faint hard X-ray sources in the Chandra deep fields selected on the basis of their high X-ray to optical flux ratio (X/O). The stacked spectra of high X/O sources in both Chandra deep fields, fitted with a single power-law model, are much harder than the spectrum of the X-ray background (XRB

Hongsu Kim, Hyung Mok Lee, Chul H. Lee, Hyun Kyu Lee

A fully general relativistic description of the pulsar magnetosphere is provided. To be more concrete, a study of the pulsar magnetosphere is performed in the context of general relativistic magnetohydrodynamics (MHD) employing the so-called Grad-Shafranov approach. Not surprisingly, the resulting Grad-Shafranov equations and all the other related general re

Blake Mellor

We use Polyak&#39;s skein relation to give a new proof that Milnor&#39;s string link homotopy invariants are finite type invariants, and to develop a recursive relation for their associated weight systems. We show that the obstruction to the triviality of these weight systems is the presence of a certain kind of spanning tree in the intersection graph of a c

G. David Forney,, Saikat Guha

Simple rate-1/3 single-error-correcting unrestricted and CSS-type quantum convolutional codes are constructed from classical self-orthogonal $\F_4$-linear and $\F_2$-linear convolutional codes, respectively. These quantum convolutional codes have higher rate than comparable quantum block codes or previous quantum convolutional codes, and are simple to decode

Brant Robertson, James S. Bullock, Andreea S. Font, Kathryn V. Johnston

(Abridged) The hierarchical formation scenario for the stellar halo requires the accretion and disruption of dwarf galaxies, yet low-metallicity halo stars are enriched in alpha-elements compared to similar, low-metallicity stars in dwarf spheroidal (dSph) galaxies. We address this primary challenge for the hierarchical formation scenario for the stellar hal

Sourish Dutta, Tanmay Vachaspati

We propose an alternate cosmological model in which our observable universe is an island in a cosmological constant sea. Initially the universe is filled with cosmological constant of the currently observed value but is otherwise empty. In this eternal or semi-eternal de Sitter spacetime, we show that local quantum fluctuations (upheavals) can violate the nu

Roberto Trinchero

Symmetries of trigonometric integrable two dimensional statistical face models are considered. The corresponding symmetry operators on the Hilbert space of states of the quantum version of these models define a weak *-Hopf algebra isomorphic to the Ocneanu double triangle algebra.

P. E. Mijnarends, S. Kaprzyk, B. Barbiellini, A. Bansil

We have carried out first principles, all-electron computations of the magnetic momentum density $ρ_{mag}({\mathbf p})$ and magnetic Compton profiles (MCPs) for momentum transfer along the [100], [001], and [110] directions in LaSr$_2$Mn$_2$O$_7$ and La$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$ within the local spin density approximation (LSDA) based band theory framewor

Eugene Levin, Michael Lublinsky

We derive an evolution equation for the generating functional which accounts for processes for both gluon emission and recombination. In terms of color dipoles, the kernel of this equation describes evolution as a classical branching process with conserved probabilities. The introduction of dipole recombination allows one to obtained closed loops during the

Sharmanthie Fernando, Chad Holbrook

In this paper we study the stability and quasi-normal modes of scalar perturbations of black holes. The static charged black hole considered here is a solution to Born-Infeld electrodynamics coupled to gravity. We conclude that the black hole is stable. We also compare the stability of it with its linear counter-part Reissner-Nordstrom black hole. The quasi-

Zvi Bern, N. E. J. Bjerrum-Bohr, David C. Dunbar

At tree-level, gravity amplitudes are obtainable directly from gauge theory amplitudes via the Kawai, Lewellen and Tye closed-open string relations. We explain how the unitarity method allows us to use these relations to obtain coefficients of box integrals appearing in one-loop N=8 supergravity amplitudes from the recent computation of the coefficients for

Hrayr H. Matevosyan, Gerald A. Miller, Anthony W. Thomas

We explore the possibility of extrapolating state of the art lattice QCD calculations of nucleon form factors to the physical regime. We find that the lattice results can be reproduced using the Light Front Cloudy Bag Model by letting its parameters be analytic functions of the quark mass. We then use the model to extend the lattice calculations to large val

J. E. Avron, O. Kenneth, D. H. Oaknin

The swimming of a pair of spherical bladders that change their volumes and mutual distance is efficient at low Reynolds numbers and is superior to other models of artificial swimmers. The change of shape resembles the wriggling motion known as {\it metaboly} of certain protozoa.

Yun Wang, Max Tegmark

We present a method for measuring the cosmic expansion history H(z) in uncorrelated redshift bins, and apply it to current and simulated type Ia supernova data assuming spatial flatness. If the matter density parameter Omega_m can be accurately measured from other data, then the dark energy density history X(z)=rho_X(z)/rho_X(0) can trivially be derived from

Kyu-Hyun Chae

We use the distribution of gravitationally-lensed image separations observed in the Cosmic Lens All-Sky Survey (CLASS) and the PMN-NVSS Extragalactic Lens Survey (PANELS), which are (nearly) complete for the image separation range $0&#39;&#39;.3 \le Δθ\le 6&#39;&#39;$, to constrain a model velocity dispersion function (VF) of early-type galaxies. Assuming a

Martin Schumacher

Different approaches to describe Compton scattering and the polarizability of the nucleon have been discussed up to now. We show that the most appropriate ones are provided by non-subtracted dispersion theories of the fixed-$t$ and fixed-$θ$ types, where the properties of these two versions are complementary so that advantage can be taken from both of them.

I. Masina, C. A. Savoy

We demonstrate the impact that present lepton flavour and CP violation data - neutrino oscillations, baryon asymmetry of the universe, flavour violations in charged lepton decays and lepton electric dipole moments - have on supersymmetric seesaw theories by analysing the class of models based on a U(1) flavour symmetry. The fermion U(1) charges are determine

A. K. INOUE, I. Iwata, J. -M. Deharveng, V. Buat

We have performed narrow-band imaging observations with the Very Large Telescope, aimed at detecting the Lyman continuum (LC) flux escaping from galaxies at z~3. We do not find any significant LC flux from our sample of two galaxies in the Hubble Deep Field South, at z=3.170 and 3.275. The corresponding lower limits on the F_{1400}/F_{900} flux density (per

V. A. Khodel, M. V. Zverev, J. W. Clark

The damping of single-particle degrees of freedom in strongly correlated two-dimensional Fermi systems is analyzed. Suppression of the scattering amplitude due to the damping effects is shown to play a key role in preserving the validity of the Landau-Migdal quasiparticle picture in a region of a phase transition, associated with the divergence of the quasip

Eduard Masso, Francesc Rota, Gabriel Zsembinszki

We use action-angle variables to describe the basic physics of coherent scalar field oscillations in the expanding universe. These analytical mechanics methods have some advantages, like the identification of adiabatic invariants. As an application, we show some instances of potentials leading to equations of state with $p<-ρ/3$, thus contributing to the dar

Baojiu Li, Ming-Chung Chu, Kai-Chung Cheung, Alfred Tang

One of the most important and surprising discoveries in cosmology in recent years is the realization that our Universe is dominated by a mysterious dark energy, which leads to an accelerating expansion of space-time. A simple generalization of the standard Friedmann-Robertson-Walker equations based on General Relativity and the Cosmological Principles with t

J. D. Fletcher, A. Carrington, O. J. Taylor, S. M. Kazakov

We report measurements of the temperature dependent anisotropies ($γ_λ$ and $γ_ξ$) of both the London penetration depth $λ$ and the upper critical field of MgB$_2$. Data for $γ_λ=λ_c/λ_a$ was obtained from measurements of $λ_{a}$ and $λ_c$ on a single crystal sample using a tunnel diode oscillator technique. $γ_ξ=H_{c2}^{\parallel c}/H_{c2}^{\bot c}$ was ded

Arnab Chatterjee, Bikas K. Chakrabarti, Robin B. Stinchcombe

We analyze an ideal gas like model of a trading market with quenched random saving factors for its agents and show that the steady state income ($m$) distribution $P(m)$ in the model has a power law tail with Pareto index $ν$ exactly equal to unity, confirming the earlier numerical studies on this model. The analysis starts with the development of a master e

M. V. Cheremisin, A. S. Furman

The beating pattern of Shubnikov-de Haas oscillations in 2D electron system in the presence of a Rashba zero-field spin splitting is reproduced. It is shown, taking into account the Zeeman splitting, that the explicit formulae for the node position well describes the experimental data. The spin-orbit interaction strength obtained is found to be magnetic fiel

Elena Gallo, Rob Fender, Christian Kaiser

Relativistic jets powered by stellar mass black holes in X-ray binaries appear to come in two types: steady outflows associated with hard X-ray states and large scale discrete ejections associated with transient outbursts. We show that the broadband radio spectrum of a `quiescent&#39; stellar mass black hole closely resembles that of canonical hard state sou

U. Tippawan, S. Pomp, A. Atac, B. Bergenwall

Double-differential cross sections for light-ion (p, d, t, He-3 and alpha) production in oxygen, induced by 96 MeV neutrons are reported. Energy spectra are measured at eight laboratory angles from 20 degrees to 160 degrees in steps of 20 degrees. Procedures for data taking and data reduction are presented. Deduced energy-differential and production cross se

Sheelan Sengupta, Arunava Chakrabarti

We propose a simple model of a waveguide network designed following the growth rule of a Vicsek fractal. We show, within the framework of real space renormalization group (RSRG) method, that such a design may lead to the appearance of unusual electromagnetic modes. Such modes exhibit an extended character in RSRG sense. However, they lead to a power law deca

Rei Inoue, Takao Yamazaki

The purpose of this paper is twofold. The first is to apply the method introduced in the works of Nakayashiki and Smirnov on the Mumford system to its variants. The other is to establish a relation between the Mumford system and the isospectral limit $\mathcal{Q}_g^{(I)}$ and $\mathcal{Q}_g^{(II)}$ of the Noumi-Yamada system. As a consequence, we prove the a

Yasufumi Hashimoto, Masato Wakayama

We introduce a Selberg type zeta function of two variables which interpolates several higher Selberg zeta functions. The analytic continuation, the functional equation and the determinant expression of this function via the Laplacian on a Riemann surface are obtained.

Dirk Englund, David Fattal, Edo Waks, Glenn Solomon

We observe large spontaneous emission rate modification of individual InAs Quantum Dots (QDs) in 2D a photonic crystal with a modified, high-Q single defect cavity. Compared to QDs in bulk semiconductor, QDs that are resonant with the cavity show an emission rate increase by up to a factor of 8. In contrast, off-resonant QDs indicate up to five-fold rate que

Akihito Shirata, Tetsuya Shiromizu, Naoki Yoshida, Yasushi Suto

In spite of the growing observational evidence for dark matter and dark energy in the universe, their physical nature is largely unknown. In fact, several authors have proposed modifications of Newton&#39;s law of gravity at cosmological scales to account for the apparent acceleration of the cosmic expansion. Inspired by such suggestions, we attempt to const

A. A. Schekochihin, S. C. Cowley, R. M. Kulsrud, G. W. Hammett

We show that under very general conditions, cluster plasmas threaded by weak magnetic fields are subject to very fast growing plasma instabilities driven by the anisotropy of the plasma pressure (viscous stress) with respect to the local direction of the magnetic field. Such an anisotropy will naturally arise in any weakly magnetized plasma that has low coll

J. Dai, M. E. Raikh, T. V. Shahbazyan

We point out a novel manifestation of many-body correlations in the linear optical response of electrons confined in a quantum well. Namely, we demonstrate that along with conventional absorption peak at frequency close to intersubband energy, there exists an additional peak at double frequency. This new peak is solely due to electron-electron interactions,

Andrea R. Rossi, Matteo G. A. Paris

A method based on Maximum-Entropy (ME) principle to infer photon distribution from on/off measurements performed with few and low values of quantum efficiency is addressed. The method consists of two steps: at first some moments of the photon distribution are retrieved from on/off statistics using Maximum-Likelihood estimation, then ME principle is applied t

T. C. Dorlas, R. F. O&#39;Connell

Recent studies suggest that both the quantum Zeno (increase of the natural lifetime of an unstable quantum state by repeated measurements) and anti-Zeno (decrease of the natural lifetime) effects can be made manifest in the same system by simply changing the dissipative decay rate associated with the environment. We present an {\underline{exact}} calculation

R. F. O&#39;Connell

We discuss various definitions of decoherence and how it can be measured. We compare and contrast decoherence in quantum systems with an infinite number of eigenstates (such as the free particle and the oscillator) and spin systems. In the former case, we point out the essential difference between assuming &#34;entanglement at all times&#34; and entanglement

C. Schoen, E. Solano, F. Verstraete, J. I. Cirac

We consider the deterministic generation of entangled multi-qubit states by the sequential coupling of an ancillary system to initially uncorrelated qubits. We characterize all achievable states in terms of classes of matrix product states and give a recipe for the generation on demand of any multi-qubit state. The proposed methods are suitable for any seque