December 2005 arXiv papers — page 10

The CDF Collaboration

We report on a measurement of the inclusive jet production cross section in pp-bar collisions at sqrt{s} = 1.96 TeV using data collected with the upgraded Collider Detector at Fermilab in Run II (CDF II) corresponding to an integrated luminosity of 385 pb^-1. Jets are reconstructed using the kt algorithm. The measurement is carried out for jets with rapidity

H1 Collaboration

Data taken with positrons of different longitudinal polarisation states in collision with unpolarised protons at HERA are used to measure the total cross sections of the charged current process, e^+ p \to \barνX, for negative four-momentum transfer squared Q^2 > 400 GeV^2 and inelasticity y<0.9. Together with the corresponding cross section obtained from the

Wesley H. Smith

The capabilities of the ATLAS and CMS detectors being prepared for the LHC are reviewed. Examples of physics signals accessible during early running and during mature high luminosity LHC operation are examined. The planning and options for the LHC and these detectors to increase the luminosity to 10^{35}cm^{-2}s^{-1} is presented. This upgrade, entitled the

D. Bazeia, C. Furtado, A. R. Gomes

Global topological defects described by real scalar field in (3,1) dimensions coupled to gravity are analyzed. We consider a class of scalar potentials with explicit dependence with distance, evading Derrick&#39;s theorem and leading to defects with spherical symmetry. The analysis shows that the defects have finite energy on flat space, contrary to the obse

Peter C. Aichelburg, Piotr Bizon, Zbislaw Tabor

Building on previous work on the critical behavior in gravitational collapse of the self-gravitating SU(2) $σ$-field and using high precision numerical methods we uncover a fine structure hidden in a narrow window of parameter space. We argue that this numerical finding has a natural explanation within a dynamical system framework of critical collapse.

R. Aldrovandi, R. R. Cuzinatto, L. G. Medeiros

It is possible to generate an accelerated period of expansion from reasonable potentials acting between the universe particle constituents. The pressure of primordial nucleons interacting via a simple nuclear potential is obtained via Mayer&#39;s cluster expansion technique. The attractive part of the potential engenders a negative pressure and may therefore

C. Klein

We review explicit solutions to the stationary axisymmetric Einstein-Maxwell equations which can be interpreted as disks of charged dust. The disks of finite or infinite extension are infinitesimally thin and constitute a surface layer at the boundary of an electro-vacuum. The Einstein-Maxwell equations in the presence of one Killing vector are obtained by u

C. Klein

We use a Harrison transformation on solutions to the stationary axisymmetric Einstein equations to generate solutions of the Einstein-Maxwell equations. The case of hyperelliptic solutions to the Ernst equation is studied in detail. Analytic expressions for the metric and the multipole moments are obtained. As an example we consider the transformation of a f

M. Melis, S. Mignemi

We study the phase space of the spherically symmetric solutions of Einstein-Maxwell-Gauss-Bonnet system nonminimally coupled to a scalar field and prove the existence of solutions with unusual asymptotics in addition to asymptotically flat ones. We also find new dyonic solutions of dilatonic Einstein-Maxwell theory.

K. Kleidis, A. Kuiroukidis, D. B. Papadopoulos, L. Vlahos

We study the linear magnetohydrodynamic (MHD) equations, both in the Newtonian and the general-relativistic limit, as regards a viscous magnetized fluid of finite conductivity and discuss instability criteria. In addition, we explore the excitation of cosmological perturbations in anisotropic spacetimes, in the presence of an ambient magnetic field. Acoustic

A. V. Minkevich, A. S. Garkun

Inflationary homogeneous isotropic cosmological models filled by scalar fields and ultrarelativistic matter are examined in the framework of gauge theories of gravitation. By using quadratic scalar field potential numerical analysis of flat, open and closed models is curried out. Properties of cosmological models are investigated in dependence on indefinite

Slava G. Turyshev

The Laser Astrometric Test of Relativity (LATOR) is a Michelson-Morley-type experiment designed to test the Einstein&#39;s general theory of relativity in the most intense gravitational environment available in the solar system -- the close proximity to the Sun. By using independent time-series of highly accurate measurements of the Shapiro time-delay (laser

David Delphenich

The basic concepts of the formulation of Maxwellian electromagnetism in the absence of a Minkowski scalar product on spacetime are summarized, with particular emphasis on the way that the electromagnetic constitutive law on the space of bivectors over spacetime supplants the role of the Minkowski scalar product on spacetime itself. The complex geometry of th

Silke Weinfurtner, Stefano Liberati, Matt Visser

Astrophysical tests of Planck-suppressed Lorentz violations had been extensively studied in recent years and very stringent constraints have been obtained within the framework of effective field theory. There are however still some unresolved theoretical issues, in particular regarding the so called &#34;naturalness problem&#34; - which arises when postulati

David Delphenich

The equations of pre-metric electromagnetism are summarized and then formulated as an exterior differential system on the total space of the bundle of 2-forms over the spacetime manifold. The Harrison-Estabrook method of computing the symmetries of the system is then applied, with the result that of the four possible formal algebras of infinitesimal symmetri

David Delphenich

Some concepts of real and complex projective geometry are applied to the fundamental physical notions that relate to Minkowski space and the Lorentz group. In particular, it is shown that the transition from an infinite speed of propagation for light waves to a finite one entails the replacement of a hyperplane at infinity with a light cone and the replaceme

Garth A. Barber

The premature acceptance of the standard cosmological model, the &#39;LambdaCDM&#39; paradigm, is questioned; Self Creation Cosmology is offered as an alternative and shown to be as equally concordant with observed cosmological constraints and local observations including the EEP. The Brans Dicke theory is modified to enable the creation of matter and energy

G. A. Barber

There are, at present, several gravitational and cosmological anomalies; the dark energy problem, the lambda problem, accelerating cosmological expansion, the anomalous Pioneer spacecraft acceleration, a spin-up of the Earth and an apparent variation of G observed from analysis of the evolution of planetary longitudes. These conundrums may be resolved in the

Stephen F. Bush, Nathan Smith

A fundamental understanding of gain provided by motion prediction in wireless ad hoc routing is currently lacking. This paper examines benefits in routing obtainable via prediction. A theoretical best-case non-predictive routing model is quantified in terms of both message overhead and update time for non-predictive routing. This best- case model of existing

Stephen F. Bush, Todd Hughes

We present progress on the experimental validation of a fundamental and universally applicable vulnerability analysis framework that is capable of identifying new types of vulnerabilities before attackers innovate attacks. This new framework proactively identifies system components that are vulnerable based upon their Kolmogorov Complexity estimates and it f

M. Dijkstra, J. Zwanikken, R. van Roij

We study sedimentation equilibrium of low-salt suspensions of binary mixtures of charged colloids, both by Monte Carlo simulations of an effective colloids-only system and by Poisson-Boltzmann theory of a colloid-ion mixture. We show that the theoretically predicted lifting and layering effect, which involves the entropy of the screening ions and a spontaneo

M. Naeem, S. K. Hasanain, M. Kobayashi, Y. Ishida

We report the crystal structure and magnetic properties of Zn1-xCoxO nanoparticles synthesized by heating metal acetates in organic solvent. The nanoparticles were crystallized in wurtzite ZnO structure after annealing in air and in a forming gas (Ar95%+H5%). The X-ray diffraction and X-ray photoemission spectroscopy (XPS) data for different Co content show

Qijin Chen, C. A. Regal, M. Greiner, D. S. Jin

Trapped ultracold Fermi gases provide a system that can be tuned between the BCS and BEC regimes by means of a magnetic-field Feshbach resonance. Condensation of fermionic atom pairs in a $^{40}$K gas was demonstrated experimentally by a sweep technique that pairwise projects fermionic atoms onto molecules. In this paper we examine previous data obtained wit

Yu-Ming Lin, Joerg Appenzeller, Joachin Knoch, Zhihong Chen

We present a systematic study on low-frequency current fluctuations of nano-devices consisting of one single semiconducting nanotube, which exhibit significant 1/f-type noise. By examining devices with different switching mechanisms, carrier types (electrons vs. holes), and channel lengths, we show that the 1/f fluctuation level in semiconducting nanotubes i

S. R. Hassan, R. Moessner

We discuss ground state selection by quantum fluctuations in frustrated magnets in a strong magnetic field. We show that there exist dynamical symmetries -- one a generalisation of Henley&#39;s gauge-like symmetry for collinear spins, the other the quantum relict of non-collinear weathervane modes -- which ensure a partial survival of the classical degenerac

V. Shelukhin, A. Tsukernik, M. Karpovski, Y. Blum

We report complementary studies of the critical temperature and the critical current in ferromagnet (Ni) - superconductor (Nb) multilayers. The observed oscillatory behavior of both quantities upon variation of the thickness of the ferromagnetic layer is found to be in good agreement with theory. The length scale of oscillations is identical for both quantit

Emmanuel O. Yewande, Reiner Kree, Alexander K. Hartmann

We study solid surface morphology created by off-normal ion-beam sputtering with an atomistic, solid-on-solid model of sputter erosion. With respect to an earlier version of the model, we extend this model with the inclusion of lateral erosion. Using the 2-dimensional structure factor, we found an upper bound $μ\simeq 2$, in the lateral straggle $μ$, for cle

G. J. Baxter, R. A. Blythe, W. Croft, A. J. McKane

We present a mathematical formulation of a theory of language change. The theory is evolutionary in nature and has close analogies with theories of population genetics. The mathematical structure we construct similarly has correspondences with the Fisher-Wright model of population genetics, but there are significant differences. The continuous time formulati

M. V. Eremin, D. V. Zakharov, R. M. Eremina, J. Deisenhofer

The strong line broadening observed in electron spin resonance on NaV$_2$O$_5$ is found to originate from an unusual type of the symmetric anisotropic exchange interaction with simultaneous spin-orbit coupling on both sites. The microscopically derived anisotropic exchange constant is almost two orders of magnitude larger than the one obtained from conventio

G. X. Tang, W. Nolting

The influence of substitutional disorder on the magnetic properties of disordered Heisenberg binary spin systems with long-range exchange integrals is studied. The equation of motion for the magnon Green&#39;s function which is decoupled by the Tyablikov approximation is solved in the Blackman-Esterling-Berk(BEB) coherent potential approximation(CPA) framewo

A. Csordas, Z. Adam

A new method is developed to calculate all excitations of trapped gases using hydrodynamics at zero temperature for any equation of state $μ=μ(n)$ and for any trapping potential. It is shown that a natural scalar product can be defined for the mode functions, by which the wave operator is hermitian and the mode functions are orthogonal. It is also shown that

A. P. Zhuravel, A. G. Sivakov, O. G. Turutanov, A. N. Omelyanchouk

The work describes the capabilities of Laser Scanning Microscopy (LSM) as a spatially resolved method of testing high_Tc materials and devices. The earlier results obtained by the authors are briefly reviewed. Some novel applications of the LSM are illustrated, including imaging the HTS responses in rf mode, probing the superconducting properties of HTS sing

Austen Lamacraft

We discuss the correlation properties of current carrying states of one-dimensional insulators, which could be realized by applying an impulse to atoms loaded onto an optical lattice. While the equilibrium noise has a gapped spectrum, the quantum uncertainty encoded in the amplitudes for the Zener process gives a zero frequency contribution out of equilibriu

Josef Schriefl, Yuriy Makhlin, Alexander Shnirman, Gerd Schön

1/f noise, the major source of dephasing in Josephson qubits, may be produced by an ensemble of two-level systems. Depending on the statistical properties of their distribution, the noise distribution can be Gaussian or non-Gaussian. The latter situation is realized, for instance, when the distribution of coupling strengths has a slowly decaying power-law ta

V. V. Bryksin, P. Kleinert

Based on the spin-density-matrix approach, both the electric-field-induced spin accumulation and the spin current are systematically studied for the two-dimensional Rashba model. Eigenmodes of spin excitations give rise to resonances in the frequency domain. Utilizing a general and physically well-founded definition of the spin current, we obtain results tha

Saloome Siavoshi, Ashish V. Orpe, Arshad Kudrolli

We investigate the effective friction encountered by a mass sliding on a granular layer as a function of bed thickness and boundary roughness conditions. The observed friction has minima for a small number of layers before it increases and saturates to a value which depends on the roughness of the sliding surface. We use an index-matched interstitial liquid

V. Sorkin, E. Polturak, Joan Adler

At low pressure, free surfaces play a crucial role in the melting transition. Under pressure, the surface of the sample is acted upon by some pressure transmitting medium. To examine the effect of this medium on melting, we performed Monte Carlo simulations of a system of argon atoms in the form of a slab with two boundaries. We examined two cases, one with

N. B. Kopnin, A. S. Mel&#39;nikov, V. M. Vinokur

We propose a mechanism of quantum pumping mediated by the spectral flow in a voltage-biased SINIS quantum junction and realized via the sequential closing of the minigaps in the energy spectrum in resonance with the Josephson frequency. We show that the dc current exhibits giant peaks at rational voltages.

Alexander P. Zhuravel, Steven M. Anlage, Alexey V. Ustinov

We propose and demonstrate a spatial partition method for the high-frequency photo-response of superconducting devices correlated with inductive and resistive changes in microwave impedance. Using a laser scanning microscope, we show that resistive losses are mainly produced by local defects at microstrip edges and by intergrain weak links in the high-temper

Chi-Ho Cheng

The modification of the boundary condition for polyelectrolyte adsorption on charged surface with short-ranged interaction is investigated under two regimes. For weakly charged Gaussian polymer in which the short-ranged attraction dominates, the boundary condition is the same as that of the neutral polymer adsorption. For highly charged polymer (compressed s

Dvira Segal

We investigate the heat conduction properties of molecular junctions comprising anharmonic interactions. We find that nonlinear interactions can lead to novel phenomena: it negative differential thermal conductance and heat rectification. Based on analytically solvable models we derive an expression for the heat current that clearly reflects the interplay be

Yoshitake Sakae, Yuko Okamoto

We propose a new backbone-torsion-energy term in the force field for protein systems. This torsion-energy term is represented by a double Fourier series in two variables, the backbone dihedral angles phi and psi. It gives a natural representation of the torsion energy in the Ramachandran space in the sense that any two-dimensional energy surface periodic in

Kazusumi Ino, Mahito Kohmoto

We numerically study a one dimensional quasiperiodic system obtained from two dimensional electrons on the triangular lattice in a uniform magnetic field aided by the multifractal method. The phase diagram consists of three phases: two metallic phases and one insulating phase separated by critical lines with one bicritical point. Novel transitions between th

J. L. Gavilano, B. Pedrini, K. Magishi, J. Hinderer

Based on experimental 59Co-NMR data in the temperature range between 0.1 and 300 K, we address the problem of the character of the Co 3d-electron based magnetism in Na0.7CoO2. Temperature dependent 59Co-NMR spectra reveal different Co environments below 300 K and their differentiation increases with decreasing temperature. We show that the 23Na- and 59Co-NMR

E. C. Samulon, Z. Islam, S. E. Sebastian, P. B. Brooks

Results of high resolution x-ray diffraction experiments are presented for single crystals of the spin gap compound BaCuSi$_2$O$_6$ in the temperature range from 16 to 300 K. The data show clear evidence of a transition from the room temperature tetragonal phase into an incommensurately modulated orthorhombic structure below $\sim$100 K. This lattice modulat

Knut Jørgen Måløy, Stéphane Santucci, Jean Schmittbuhl, Renaud Toussaint

The propagation of an interfacial crack along a heterogeneous weak plane of a transparent Plexiglas block is followed using a high resolution fast camera. We show that the fracture front dynamics is governed by local and irregular avalanches with very large size and velocity fluctuations. We characterize the intermittent dynamics observed, i.e. the local pin

N. A. Mortensen, F. Okkels, H. Bruus

We show that in edge-source diffusion dynamics the integrated concentration N(t) has a universal dependence with a characteristic time-scale tau=(A/P)^2 pi/(4D), where D is the diffusion constant while A and P are the cross-sectional area and perimeter of the domain, respectively. For the short-time dynamics we find a universal square-root asymptotic depende

Rahul Marathe, Abhishek Dhar

We compute the distribution of the work done in driving a single Ising spin with a time-dependent magnetic field. Using Glauber dynamics we perform Monte-Carlo simulations to find the work distributions at different driving rates. We find that in general the work-distributions are broad with a significant probability for processes with negative dissipated wo

Michiel Snoek, Masudul Haque, S. Vandoren, H. T. C. Stoof

We propose a setup with ultracold atomic gases that can be used to make a nonrelativistic superstring in four spacetime dimensions. In particular, we consider for the creation of the superstring a fermionic atomic gas that is trapped in the core of a vortex in a Bose-Einstein condensate. We explain the required tuning of experimental parameters to achieve su

James W. Colbert, Harry Teplitz, Paul Francis, Povilas Palunas

We present Spitzer Space Telescope observations of the z=2.38 lya-emitter over-density associated with galaxy cluster J2143-4423, the largest known structure (110 Mpc) above z=2. We imaged 22 of the 37 known lya-emitters within the filament-like structure, using the MIPS 24um band. We detected 6 of the lya-emitters, including 3 of the 4 clouds of extended (>

A. Avgoustidis, E. P. S. Shellard

We perform numerical simulations of cosmic string evolution with intercommuting probability $P$ in the range $5\times 10^{-3}\le P\le 1$, both in the matter and radiation eras, using a modified version of the Allen-Shellard code. We find that the dependence of the scaling density on $P$ is significantly different than the suggested $ρ\propto P^{-1}$ form. In

Yuri Lyubarsky, David Eichler

It is estimated that the Weibel instability is not generally an effective mechanism for generating ultrarelativistic astrophysical shocks. Even if the upstream magnetic field is as low as in the interstellar medium, the shock is mediated not by the Weibel instability but by the Larmor rotation of protons in the background magnetic field. Future simulations s

T. Q. Donaghy

Gamma-Ray Bursts (GRBs) are widely thought to originate from collimated jets of material moving at relativistic velocities. Emission from such a jet should be visible even when viewed from outside the angle of collimation. I summarize recent work on the special relativistic transformation of the burst quantities Eiso and Epeak as a function of viewing angle,

Ruth A. Daly, S. G. Djorgovski

Understanding the physical nature of the dark energy which appears to drive the accelerated expansion of the unvierse is one of the key problems in physics and cosmology today. This important problem is best studied using a variety of mutually complementary approaches. Daly and Djorgovski (2003, 2004) proposed a model independent approach to determine a numb

D. A. Kann, S. Klose, A. Zeh

We present the results of a systematic analysis of gamma-ray burst afterglow spectral energy distributions (SEDs) in the optical/near-infrared bands. Our input list includes the entire world sample of afterglows observed in the pre-Swift era by the end of 2004 that have sufficient publicly available data. We apply various dust extinction models to fit the ob

F. Patat, S. Benetti, E. Cappellaro, M. Turatto

In this paper we present and discuss the effects of scattered light echoes (LE) on the luminosity and spectral appearance of Type Ia Supernovae (SNe). After introducing the basic concepts of LE spectral synthesis, by means of LE models and real observations we investigate the deviations from pure SN spectra, light and colour curves, the signatures that witne

J. G. Kirk, O. Tsang

Some rapidly variable extra-galactic radio sources show very high brightness temperatures T_B>10^{12}K and high degrees of circular polarisation (1%). Standard synchrotron models that assume a power-law electron distribution cannot produce such high temperatures and have much lower degrees of intrinsic circular polarisation. We examine the synchrotron and in

F P Keenan, K M Aggarwal, D S Bloomfield, A Z Msezane

Previously, large discrepancies have been found between theory and observation for Fe XV emission line ratios in solar flare spectra covering the 224-327 A wavelength range, obtained by the Naval Research Laboratory&#39;s S082A instrument on board Skylab. These discrepancies have been attributed to either errors in the adopted atomic data or the presence of

Jose A. R. Cembranos, Antonio Dobado, Jonathan L. Feng, Antonio L. Maroto

We summarize the main features of several dark matter candidates in extra-dimensional theories. In particular, we review Kaluza-Klein (KK) gravitons in universal extra dimensions and branons in brane-world models. KK gravitons are superWIMP (superweakly-interacting massive particle) dark matter, and branons are WIMP (weakly-interacting massive particle) dark

Vadim V. Bobylev

We analyzed the space velocities of Gould Belt stars younger than 125 Myr located at heliocentric distances <650 pc. We determined the rotation and expansion parameters of the Gould Belt by assuming the existence of a single kinematic center whose direction was found to be the following: $l_\circ=128^\circ$ and $R_\circ=150$ pc. The linear velocities reach t

M. Koenig, K. Beuermann, B. T. Gaensicke

We present a pilot study of atmospheres of accreting magnetic white dwarfs irradiated by intense fluxes at ultraviolet to infrared wavelengths. The model uses a standard LTE stellar atmosphere code which is expanded by introducing an angle-dependent external radiation source. The present results are obtained for an external source with the spectral shape of

H. J. Drescher

The hadronic interaction model BBL implements the ideas of gluon saturation due to large densities. When approaching the black body limit at high energies, leading partons acquire large transverse momenta which breaks up their coherence. This leads to a suppression of forward scattering, and is therefore important for air showers. We discuss some general asp

Ch. Nieten, N. Neininger, M. Guelin, H. Ungerechts

We present a new 12CO(J=1-0)-line survey of the Andromeda galaxy, M31, covering the bright disk with the highest resolution to date (85 pc along the major axis), observed On-the-Fly (in italics) with the IRAM 30-m telescope. We discuss the distribution of the CO emission and compare it with the distributions of HI and emission from cold dust traced at 175mum

B. Acke, M. E. van den Ancker

Aims. We intend to spatially and spectrally resolve the [O I] emission region in two nearby Herbig stars. Methods. We present high-resolution (R = 80,000) VLT/UVES echelle spectra of the [O I] 6300A line in the Herbig Ae/Be stars HD 97048 and HD 100546. Apart from the spectral signature, also the spatial extent of the [O I] emission region is investigated. F

S. Pilling, A. C. F. Santos, H. M. Boechat-Roberty

Fragments from organic molecule dissociation (such as reactive ions and radicals) can form interstellar complex molecules like amino acids. The goal of this work is to experimentally study photoionization and photodissociation processes of acetic acid (CH$_3$COOH), a glycine (NH$_2$CH$_2$COOH) precursor molecule, by soft X-ray photons. The measurements were

A. Poncelet, G. Perrin, H. Sol

We present a new analysis of the very first mid-infrared N-band long-baseline interferometric observations of an extragalactic source: the nucleus of the Seyfert 2 galaxy NGC 1068, obtained with MIDI (Mid-InfrareD Interferometer), the mid-infrared beamcombiner at the European Southern Observatory (ESO) Very Large Telescope Interferometer (VLTI). The resoluti

Andreas Kelz, Marc A. W. Verheijen, Martin M. Roth, Svend M. Bauer

PPak is a new fiber-based Integral Field Unit (IFU), developed at the Astrophysical Institute Potsdam, implemented as a module into the existing PMAS spectrograph. The purpose of PPak is to provide both an extended field-of-view with a large light collecting power for each spatial element, as well as an adequate spectral resolution. The PPak system consists

Christian Motch, Raimundo Lopes de Oliveira, Ignacio Negueruela, Frank Haberl

A growing number of early Be stars discovered in X-ray surveys exhibit X-ray luminosities intermediate between those of normal stars and those of most Be/X-ray binaries in quiescence. Their X-ray spectra are also much harder than those of shocked wind OB stars and can be best fitted by a thin thermal plasma with T ~ 10^8 K, added to a cooler and much fainter

X. F. Wu, Z. G. Dai, X. Y. Wang, Y. F. Huang

We analyze several recently detected gamma-ray bursts (GRBs) with late X-ray flares in the context of late internal shock and late external shock models. We find that the X-ray flares in GRB 050421 and GRB 050502B originate from late internal shocks, while the main X-ray flares in GRB 050406 and GRB 050607 may arise from late external shocks. Under the assum

D. Vogt, P. S. Letelier

In this comment we question some arguments presented in astro-ph/0512048 to refuse the presence of an singular mass surface layer. In particular, incorrect expressions are used for the disk&#39;s surface mass density. We also point out that the procedure of removing the descontinuity on the $z=0$ plane with a region of continuous density gradient generates o

J. M. Miller, A. C. Fabian, M. C. Miller

In this letter, we comment on the robustness of putative cool (kT ~ 0.2 keV) accretion disc components in the X-ray spectra of the most luminous (L ~ 10^40 erg/s) ultra-luminous X-ray sources (ULXs) in nearby normal galaxies. When compared to stellar-mass black holes, the low disc temperatures observed in some ULXs may imply intermediate-mass black hole prim

A. E. Hornschemeier, B. Mobasher, D. M. Alexander, F. E. Bauer

We have performed a pilot Chandra survey of an off-center region of the Coma cluster to explore the X-ray properties and Luminosity Function of normal galaxies. We present results on 13 Chandra-detected galaxies with optical photometric matches, including four spectroscopically-confirmed Coma-member galaxies. All seven spectroscopically confirmed giant Coma

Garth A. Barber

The theory of Self Creation Cosmology is described and found to be as concordant as the standard cosmological &#39;concordance model&#39; with local experiments and cosmological observations. However it does not require the speculative hypotheses of inflation, dark matter or dark energy. The theory is highly predictive and when its only free parameter, H, is

S. Kraml, A. R. Raklev

We present a new method to search for a light scalar top with $m_{\tilde{t}_1}\lsim m_t$, decaying dominantly into a c-jet and the lightest neutralino, at the LHC. The principal idea is to exploit the Majorana nature of the gluino, leading to same-sign top quarks in events of gluino-pair production followed by gluino decays into top and stop. The resulting s

V. A. Belavin, M. N. Chernodub, I. E. Kozlov

We suggest that the gauge-invariant hedgehoglike structures in the Wilson loops are physically interesting degrees of freedom in the Yang--Mills theory. The trajectories of these ``hedgehog loops&#39;&#39; are closed curves corresponding to center-valued (untraced) Wilson loops and are characterized by the center charge and winding number. We show numericall

D. Fernandez-Fraile, A. Gomez Nicola

The electrical conductivity of a pion gas at low temperatures is studied in the framework of Linear Response and Chiral Perturbation Theory. The standard ChPT power counting has to be modified to include pion propagator lines with a nonzero thermal width in order to properly account for collision effects typical of Kinetic Theory. With this modification, we

Slava G. Turyshev, Viktor T. Toth, Larry R. Kellogg, Eunice. L. Lau

Radiometric tracking data from Pioneer 10 and 11 spacecraft has consistently indicated the presence of a small, anomalous, Doppler frequency drift, uniformly changing with a rate of ~6 x 10^{-9} Hz/s; the drift can be interpreted as a constant sunward acceleration of each particular spacecraft of a_P = (8.74 \pm 1.33) x 10^{-10} m/s^2. This signal is known a

Ishwaree P Neupane, Benedict M N Carter

We consider a physically viable cosmological model that has a field dependent Gauss-Bonnet coupling in its effective action, in addition to a standard scalar field potential. The presence of such terms in the four dimensional effective action gives rise to several novel effects, such as a four dimensional flat Friedmann-Robertson-Walker universe undergoing a

Simon Wicks, William Horowitz, Magdalena Djordjevic, Miklos Gyulassy

We propose a possible perturbative QCD solution to the heavy quark tomography problem posed by recent non-photonic single electron data from central Au+Au collisions at $\sqrt{s} = 200$ AGeV. Jet quenching theory is extended to include (1) elastic as well as (2) inelastic parton energy losses and (3) jet path length fluctuations. The three effects combine to

Ryan C. Hickox, Maxim Markevitch

We present the absolute measurement of the unresolved 0.5-8 keV cosmic X-ray background (CXB) in the Chandra Deep Fields (CDFs) North and South, the longest observations with Chandra (2 Ms and 1 Ms, respectively). We measure the unresolved CXB intensity by extracting spectra of the sky, removing all point and extended sources detected in the CDF. To model an

P. Q. Hung

A dynamical model for the dark energy is presented in which the ``quintessence&#39;&#39; field is the axion, $a_Z$, of a spontaneously broken global $U(1)_{A}^{(Z)}$ symmetry whose potential is induced by the instantons of a new gauge group $SU(2)_Z$. The $SU(2)_Z$ coupling becomes large at a scale $Λ_Z \sim 10^{-3} eV$ starting from an initial value $M$ at

CLEO Collaboration, J. L. Rosner

We determine the di-electron widths of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) resonances with better than 2% precision by integrating the cross-section of e+e- -> Upsilon over the e+e- center-of-mass energy. Using e+e- energy scans of the Upsilon resonances at the Cornell Electron Storage Ring and measuring Upsilon production with the CLEO detector, w

A. A. Saharian, M. R. Setare

The vacuum expectation value of the surface energy-momentum tensor is evaluated for a scalar field obeying Robin boundary condition on a spherical brane in (D+1)-dimensional spacetime $Ri\times S^{D-1}$, where $Ri$ is a two-dimensional Rindler spacetime. The generalized zeta function technique is used in combination with the contour integral representation.

Dijana Jakelic

We investigate the interplay of crystal bases and completions in the sense of Enright on certain nonintegrable representations of quantum groups. We define completions of crystal bases, show that this notion of completion is compatible with Enright&#39;s completion of modules, prove that every module in our category has a crystal basis which can be completed

Claus Heussinger, Erwin Frey

We study the elasticity of cross-linked networks of thermally fluctuating stiff polymers. As compared to their purely mechanical counterparts, it is shown that these thermal networks have a qualitatively different elastic response. By accounting for the entropic origin of the single-polymer elasticity, the networks acquire a strong susceptibility to polydisp

V. Cardoso, O. J. C. Dias, J. L. Hovdebo, R. C. Myers

Recently certain non-supersymmetric solutions of type IIb supergravity were constructed [hep-th/0504181], which are everywhere smooth, have no horizons and are thought to describe certain non-BPS microstates of the D1-D5 system. We demonstrate that these solutions are all classically unstable. The instability is a generic feature of horizonless geometries wi

J. Kinnunen, L. M. Jensen, P. Torma

We consider density-imbalanced Fermi gases of atoms in the strongly interacting, i.e. unitarity, regime. The Bogoliubov-deGennes equations for a trapped superfluid are solved. They take into account the finite size of the system, as well as give rise to both phase separation and FFLO type oscillations in the order parameter. We show how radio-frequency spect

Marek Biskup, Roman Kotecky

We consider the (scalar) gradient fields $η=(η_b)$--with $b$ denoting the nearest-neighbor edges in $\Z^2$--that are distributed according to the Gibbs measure proportional to $\texte^{-βH(η)}ν(\textdη)$. Here $H=\sum_bV(η_b)$ is the Hamiltonian, $V$ is a symmetric potential, $β>0$ is the inverse temperature, and $ν$ is the Lebesgue measure on the linear spa

Minoru Biyajima, Takuya Mizoguchi, Naomichi Suzuki

In previous works, in order to include correction by the Coulomb wave function in Bose-Einstein correlations (BEC), the two-body Coulomb scattering wave functions have been utilized in the formulation of three-body BEC. However, the three-body Coulomb scattering wave function, which satisfies approximately the three-body Coulomb scattering Schrodinger equati

Gael Reinaudi, Alice Sinatra, Aurelien Dantan, Michel Pinard

We present a realistic model for transferring the squeezing or the entanglement of optical field modes to the collective ground state nuclear spin of $^3$He using metastability exchange collisions. We discuss in detail the requirements for obtaining good quantum state transfer efficiency and study the possibility to readout the nuclear spin state optically.

Christopher King, Nilufer Koldan

Let $Φ$ be a trace-preserving, positivity-preserving (but not necessarily completely positive) linear map on the algebra of complex $2 \times 2$ matrices, and let $Ω$ be any finite-dimensional completely positive map. For $p=2$ and $p \geq 4$, we prove that the maximal $p$-norm of the product map $Φ\ot Ω$ is the product of the maximal $p$-norms of $Φ$ and $Ω

Magno V. T. Machado

At small-x, the structure function F_L(x,Q2) is driven by the gluon content of the nucleon target and consequently it can unravel the underlying QCD dynamics in that region. In this work, one studies its behavior on photon virtuality Q2 at fixed energy within the color dipole formalism for models considering parton saturation effects. The reason is that they

TWQCD Collaboration, Ting-Wai Chiu, Tung-Han Hsieh

We investigate the mass spectra of closed-charm mesons with $ J^{PC} = 1^{--} $, for hybrid charmonium, molecules, and diquark-antidiquark operators, in quenched lattice QCD with exact chiral symmetry. For two lattice volumes $ 24^3 \times 48 $ and $ 20^3 \times 40 $, each of 100 gauge configurations generated with single-plaquette action at $ β= 6.1 $, we c

NA49 Collaboration

The transverse mass distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20A, 30A, 40A and 80A GeV beam energies in the fixed target experiment NA49 at the CERN SPS. The rapidity density, inverse slope parameter and mean transverse mass derived from the transverse mass dis

Tobias A. Gail, Thomas R. Hemmert

Utilizing the methods of chiral effective field theory we present an analysis of the electromagnetic $NΔ$-transition current in the framework of the non-relativistic &#34;small scale expansion&#34; (SSE) to leading-one-loop order. We discuss the momentum dependence of the magnetic dipole, electric quadrupole and coulomb quadrupole transition form factors up

Arthur D. Yaghjian, Thorkild B. Hansen

Plane-wave representations are used to formulate the exact solutions to frequency-domain and time-domain sources illuminating a magnetodielectric slab with complex permittivity and permeability. In the special case of a line source at z=0 a distance d<L in front of an L wide lossless double negative (DNG) slab with permittivity and permeability equal to -1,

Graham Denham, Alexander I. Suciu

Associated to every finite simplicial complex K there is a &#34;moment-angle&#34; finite CW-complex, Z_K; if K is a triangulation of a sphere, Z_K is a smooth, compact manifold. Building on work of Buchstaber, Panov, and Baskakov, we study the cohomology ring, the homotopy groups, and the triple Massey products of a moment-angle complex, relating these topol

Wei-Shu Hou, Andrea Soddu

We extend the eV seesaw scenario to four lepton generations. The LSND anomaly is taken as the right-handed seesaw scale, i.e. m_R ~ eV. The fourth generation then gives a heavy pseudo-Dirac neutrino which largely decouples from other generations, and is relatively stable. One effectively has a 3+3 solution to the LSND anomaly, where we illustrate with numeri

Liviu I. Nicolaescu

This paper was motivated by work of Arnold where he explains how to count &#34;snakes&#34;, i.e. Morse functions on the real axis with prescribed behavior at infinity. This leads immediately to a count of excellent Morse functions on the circle, where following Thom&#39;s terminology, excellent means that no two critical points lie on the same level set. We

Fabrizio Palumbo

I recently proposed a method of bosonization based on the use of coherent states of fermion composites, whose validity was restricted to smooth structure functions. In the present paper I remove this limitation and derive results which hold for arbitrary interactions and structure functions. The method respects all symmetries and in particular fermion number