February 2006 arXiv papers — page 10

Pietro Menotti, Erik Tonni

We develop a general technique for computing functional integrals with fixed area and boundary length constraints. The correct quantum dimensions for the vertex functions are recovered by properly regularizing the Green function. Explicit computation is given for the one point function providing the first one loop check of the bootstrap formula.

Richard Battye, Paul Sutcliffe

In the Skyrme model with massless pions, the minimal energy multi-Skyrmions are shell-like, with the baryon density localized on the edges of a polyhedron that is approximately spherical and generically of the fullerene-type. In this paper we show that in the Skyrme model with massive pions these configurations are unstable for sufficiently large baryon numb

Kazunari Shima, Motomu Tsuda

We focus on a spin-3/2 supersymmetry (SUSY) algebra of Baaklini in D = 3 and explicitly show a nonlinear realization of the SUSY algebra. The unitary representation of the spin-3/2 SUSY algebra is discussed and compared with the ordinary (spin-1/2) SUSY algebra.

Adam Martin

We investigate a variation of the Simplest Little Higgs (SLH) model that is invariant under a discrete $\CZ_2$ symmetry. Our motivation for imposing this symmetry is the two dark matter candidates it implies, a scalar $η$ and a heavy neutrino. We examine the viability of these two candidates using the standard relic abundance calculation. Direct detection pr

Michael Dinsdale, Marko Ternick, Stefan Weinzierl

We compare four different methods for the numerical computation of the pure gluonic amplitudes in the Born approximation. We are in particular interested in the efficiency of the various methods as the number n of the external particles increases. In addition we investigate the numerical accuracy in critical phase space regions. The methods considered are ba

Shibaji Banerjee, Abhijit Bhattacharyya, Sanjay K. Ghosh, Ernst-Michael lgenfritz

The present day astrophysical observations indicate that the universe is composed of a large amount of dark energy (DE) responsible for an accelerated expansion of the universe, along with a sizeable amount of cold dark matter (CDM), responsible for structure formation. The explanations for the origin or the nature of both CDM and DE seem to require ideas be

Narendra Sahu

Baryogenesis via leptogenesis is an attractive scenario that links the physics of right handed neutrino sector with the low energy neutrino data. In the light of current neutrino oscillation data we studied the bound on the mass scale ($M_1$) of lightest right handed neutrino ($N_1$) as well as their mass hierarchy ($M_2/M_1$ and $M_3/M_1$) from the leptogen

Haigang Lu

The inconsistence of Dirac-Weyl field equations with the universal U(1) gauge invariance of neutrinos in quantum mechanics led to generalize the special relativity to the generic relativity, which was composed of the special relativity and its three analogues with different signatures of metrics. The combination of the universal U(1) gauge invariance and the

Bernhard U. Musch

This work discusses reliability, possible obstacles and the future perspective of chiral extrapolation of lattice results. In the first part, chiral perturbation theory fits to lattice calculations of the nucleon mass are thoroughly explored in terms of statistical uncertainty and convergence. Lattice volume dependence is exploited as a source of additional

M. Göckeler, R. Horsley, A. C. Irving, D. Pleiter

Using the O(a) Symanzik improved action an estimate is given for the strange quark mass for unquenched (n_f=2) QCD. The determination is via the axial Ward identity (AWI) and includes a non-perturbative evaluation of the renormalisation constant. Numerical results have been obtained at several lattice spacings, enabling the continuum limit to be taken. Our r

K. A. Milton

The Tevatron has inspired new interest in the subject of magnetic monopoles. First there was the 1998 D0 limit on the virtual production of monopoles, based on the theory of Ginzburg and collaborators. In 2000 and 2004 results from an experiment (Fermilab E882) searching for real magnetically charged particles bound to elements from the CDF and D0 detectors

Thomas Nunnemann

A search for charged massive (quasi-) stable particles with the D0 detector at the Tevatron collider based on 390 pb^{-1} of data is presented. The search is performed in the frameworks of gauge-mediated supersymmetry breaking and the minimal supersymmetric extentension of the standard model. The hypothetical particles are assumed to be pair-produced in p-an

Thomas Nunnemann

Searches for the supersymmetric partners of top and bottom quarks using data up to 340 pb$^{-1}$ taken at the Tevatron $p\bar{p}$ collider are described. We report on searches for scalar top quarks $\tilde{t}$ in the decays $\tilde{t}\to c \tildeχ_1^0$ and $\tilde{t}\to bl\tildeν$ and for scalar bottom quarks $\tilde{b}$ in the decay $\tilde{b}\to b \tildeχ_

A. S. Barabash

The present status of double beta decay experiments are reviewed. The results of the most sensitive experiments, NEMO-3 and CUORICINO, are discussed. Proposals for future double beta decay experiments are considered. In these experiments sensitivity for the effective neutrino mass will be on the level of (0.1-0.01) eV.

Vladimir V. Kassandrov

We present a scheme of biquaternionic algebrodymamics based on a nonlinear generalization of the Cauchy-Riemann holomorphy conditions considered therein as fundamental field equations. The automorphism group SO(3,C) of the biquaternion algebra acts as a proper Lorentz group on a real space whose coordinates are bilinear in the complex coordinates of biquater

Sergei M. Kopeikin, Edward B. Fomalont

Recent papers by Samuel declared that the linearized post-Newtonian v/c effects are too small to have been measured in the recent experiment involving Jupiter and quasar J0842+1845 that was used to measure the ultimate speed of gravity defined as a fundamental constant entering in front of each time derivative of the metric tensor in the Einstein gravity fie

Sheung-Hung Poon, Shripad Thite

A pants decomposition of an orientable surface S is a collection of simple cycles that partition S into pants, i.e., surfaces of genus zero with three boundary cycles. Given a set P of n points in the plane, we consider the problem of computing a pants decomposition of the surface S which is the plane minus P, of minimum total length. We give a polynomial-ti

Xi Chen, Xiaotie Deng, Shang-Hua Teng

We show that the BIMATRIX game does not have a fully polynomial-time approximation scheme, unless PPAD is in P. In other words, no algorithm with time polynomial in n and 1/εcan compute an ε-approximate Nash equilibrium of an n by nbimatrix game, unless PPAD is in P. Instrumental to our proof, we introduce a new discrete fixed-point problem on a high-dimensi

J. Reyes-Esqueda, B. Darracq, J. Garcia-Macedo, M. Canva

In the last years, important non-linear optical results on sol-gel and polymeric materials have been reported, with values comparable to those found in crystals. These new materials contain push-pull chromophores either incorporated as guest in a high Tg polymeric matrix (doped polymers) or grafted onto the polymeric matrix. These systems present several adv

Jorge-Alejandro Reyes-Esqueda, Laurent Vabre, Romain Lecaque, Francois Ramaz

We report on the recording of 3D optical memories in sol-gel materials by using a non-linear absorption effect. This effect induces a local change of the optical properties of the material which is read and quantified with a high resolution full-field Optical Coherence Tomography setup. It is the first time that this technique is used for this purpose. Data

Alexander V. Balatsky, Elihu Abrahams

Basing our arguments on a wave function that contains both positional and superfluid order, we propose a Ginzburg-Landau functional for a supersolid with the two order parameters necessary to describe such a phase: density n_B(r) and supersolid order parameter ψ_V. We argue that adding lighter $^3$He atoms to a 4He supersolid produces attractive regions for

Tommaso Roscilde

In the present paper we discuss the rich phase diagram of S=1/2 weakly coupled dimer systems with site dilution as a function of an applied uniform magnetic field. Performing quantum Monte Carlo simulations on a site-diluted bilayer system, we find a sequence of three distinct quantum-disordered phases induced by the field. Such phases divide a doping-induce

M. Serrano, G. De Fabritiis, P. Español, P. V. Coveney

In this article we show in details the derivation of an integration scheme for the dissipative particle dynamic model (DPD) using the stochastic Trotter formula [De Fabritiis et al., Physica A, 361, 429 (2006)]. We explain some subtleties due to the stochastic character of the equations and exploit analyticity in some interesting parts of the dynamics. The D

S. Brown, J. Cao, J. L. Musfeldt, N. Dragoe

We report the high-resolution far infrared vibrational properties of C60 and endohedral Kr@C60 fullerene as a function of temperature. Anomalous softening of the F1u(1) mode (526 cm-1) is observed throughout the temperature range of investigation (300 - 10 K) suggesting that the fullerene cage may expand at low temperature in these molecular solids. To test

Henrik Brenning, Sergey Kafanov, Tim Duty, Sergey Kubatkin

We present the fabrication and measurement of a radio frequency single electron transistor (rf-SET), that displays a very high charge sensitivity of 1.9 microlectrons/sqrt(Hz) at 4.2 K. At 40 mK, the charge sensitivity is 0.9 and 1.0 microlectrons/sqrt(Hz) in the superconducting and normal state respectively. The sensitivity was measured as a function of rad

O. Bleibaum, S. Wachsmuth

We study the spin-Hall effect in systems with weak cubic Rashba spin-orbit interaction. To this end we derive particle and spin diffusion equations and explicit expressions for the spin-current tensor in the diffusive regime. We discuss the impact of electric fields on the Green's functions and the diffusion equations and establish a relationship between

W. Heiss, H. Groiss, E. Kaufmann, G. Hesser

A concept for the fabrication of highly symmetric quantum dots that are coherently embedded in a single crystalline matrix is demonstrated. In this approach, the formation of the quantum dots is induced by a transformation of an epitaxial 2D quantum well into an array of isolated precipitates with dimensions of about 25 nm. The formation process is driven by

U. M. S. Costa, V. N. Freire, L. C. Malacarne, R. S. Mendes

In this work, we address modal parameter fluctuations in statistical distributions describing charge-to-breakdown $(Q_{BD})$ and/or time-to-breakdown $(t_{BD})$ during the dielectric breakdown regime of ultra-thin oxides, which are of high interest for the advancement of electronic technology. We reobtain a generalized Weibull distribution ($q$-Weibull), whi

Luis G. Moyano, Ana P. Majtey, Constantino Tsallis

We introduce, and numerically study, a system of $N$ symplectically and globally coupled standard maps localized in a $d=1$ lattice array. The global coupling is modulated through a factor $r^{-α}$, being $r$ the distance between maps. Thus, interactions are {\it long-range} (nonintegrable) when $0\leqα\leq1$, and {\it short-range} (integrable) when $α>1$. W

S. -R. Eric Yang, N. Y. Hwang

We propose that n-type semiconductor quantum dots with the Rashba and Dresselhaus spin orbit interactions may be used for single electron manipulation through adiabatic transformations between degenerate states. All the energy levels are discrete in quantum dots and possess a double degeneracy due to time reversal symmetryin the presence of the Rashba and/or

D. M. Basko, I. L. Aleiner, B. L. Altshuler

We review recent progress in the study of transport properties of interacting electrons subject to a disordered potential which is strong enough to localize all single-particle states. This review may also serve as a guide to the recent paper by the authors [Annals of Physics (2006), in press]. Here we skip most of the technical details and make an attempt t

K. S. Buchanan, P. E. Roy, M. Grimsditch, F. Y. Fradin

Confinement alters the energy landscape of nanoscale magnets, leading to the appearance of unusual magnetic states, such as vortices, for example. Many basic questions concerning dynamical and interaction effects remain unanswered, and nanomagnets are convenient model systems for studying these fundamental physical phenomena. A single vortex in restricted ge

W. Meevasana, N. J. C. Ingle, D. H. Lu, J. R. Shi

A recent highlight in the study of high-Tc superconductors is the observation of band renormalization / self-energy effects on the quasiparticles. This is seen in the form of kinks in the quasiparticle dispersions as measured by photoemission and interpreted as signatures of collective bosonic modes coupling to the electrons. Here we compare for the first ti

P. K. Polinák, C. J. Lambert, J. Koltai, J. Cserti

We study a new hybrid normal-superconductor (NS) pi-junction in which the non-local current can be orders of magnitude larger than that in earlier proposed systems. We calculate the electronic transport of this NS hybrid when an external magnetic field is applied. It is shown that the non-local current exhibits oscillations as a function of the magnetic fiel

Paolo Politi, Chaouqi Misbah

We develop a general criterion about coarsening for a class of nonlinear evolution equations describing one dimensional pattern-forming systems. This criterion allows one to discriminate between the situation where a coarsening process takes place and the one where the wavelength is fixed in the course of time. An intermediate scenario may occur, namely `int

S. Nonnenmacher, A. Voros

We study individual eigenstates of quantized area-preserving maps on the 2-torus which are classically chaotic. In order to analyze their semiclassical behavior, we use the Bargmann-Husimi representations for quantum states, as well as their stellar parametrization, which encodes states through a minimal set of points in phase space (the constellation of zer

Ari Brynjolfsson

We have previously shown that the type Ia supernovae data by Riess et al. match the prediction of the magnitude-redshift relation in the plasma-redshift cosmology. In this article, we also show that the recent SNLS data, which have a slightly narrower distribution as reported by Astier et al. in 2005, match the predictions of the plasma-redshift cosmology. T

Shane W. Davis, Ivan Hubeny

Self-consistent vertical structure models together with non-LTE radiative transfer should produce spectra from accretion disks around black holes which differ from multitemperature blackbodies at levels which may be observed. High resolution, high signal-to-noise observations warrant spectral modeling which both accounts for relativistic effects, and treats

G. Ghirlanda, G. Ghisellini

Gamma Ray Bursts are among the most powerful astrophysical sources and they release up to 1.e54 erg, if isotropic, in less than few hundred seconds. Their detection in the hard X/gamma ray band (at energies >10 keV) and out to very high redshift (z~6.3) makes them a powerful new cosmological tool (a) to study the reionization epoch, (b) to unveil the propert

Paul Martini, Daniel D. Kelson, Eunhyeuk Kim, John S. Mulchaey

We have completed a spectroscopic survey of X-ray point sources in eight low-redshift clusters of galaxies (0.05<z<0.31) and have identified 40 cluster members with broad-band (0.3-8 keV) X-ray luminosities between L_X = 8x10^{40} and 4x10^{43} erg/s. There are between two and ten X-ray sources per cluster. We use visible-wavelength emission lines, X-ray spe

S. F. Hoenig, T. Beckert, K. Ohnaka, G. Weigelt

Recent observations of NGC 1068 and other AGN support the idea of a geometrically and optically thick dust torus surrounding the central supermassive black hole and accretion disk of AGN. In type 2 AGN, the torus is seen roughly edge-on, leading to obscuration of the central radiation source and a silicate absorption feature near 10 micron. While most of the

A. Moitinho, R. A. Vazquez, G. Carraro, G. Baume

With the discovery of the Sagittarius dwarf spheroidal (Ibata et al. 1994), a galaxy caught in the process of merging with the Milky Way, the hunt for other such accretion events has become a very active field of astrophysical research. The identification of a stellar ring-like structure in Monoceros, spanning more than 100 degrees (Newberg et al. 2002), and

Simon Goodchild, Gordon Ogilvie

We have applied an eccentric accretion disc theory in simplified form to the case of an accretion disc in a binary system, where the disc contains the 3:1 Lindblad resonance. This is relevant to the case of superhumps in SU Ursae Majoris cataclysmic variables and other systems, where it is thought that this resonance leads to growth of eccentricity and a mod

A. J. Delgado, O. Gonzalez-Martin, E. J. Alfaro, J. Lin Yun

We present a multiwavelength analysis of the young open cluster NGC 2362. UBVRcIc CCD photometric observations, together with available data in the Chandra data base, near infrared data from the Two Micron All Sky Survey (2MASS), and recently published Halpha spectroscopy were used to get information about the evolutionary stage of the cluster and the main p

P. Severgnini, A. Caccianiga, V. Braito, R. Della Ceca

We present the XMM-Newton and the optical-VLT spectra along with the optical and the near-infrared photometric data of one of the brightest X-ray (F(2-10 keV)~1e-13 erg/s cm^2) extremely red objects (R-K>=5) discovered so far. The source, XBSJ0216-0435, belongs to the XMM-Newton Bright Serendipitous Survey and it has extreme X-ray-to-optical (~220) and X-ray

Andrea Nagy, Geza Kovacs

By using the full span of multicolor data on a representative sample of first overtone RR Lyrae stars in the Large Magellanic Cloud (LMC) we revisit the problem of the incidence rate of the amplitude/phase-modulated (Blazhko) stars. Multicolor data, obtained by the MAssive Compact Halo Objects (MACHO) project, are utilized through a periodogram averaging met

F. Elias, J. Cabrera-Cano, E. J. Alfaro

We present a newly-developed, three-dimensional spatial classification method, designed to analyze the spatial distribution of early type stars within the 1 kpc sphere around the Sun. We propose a distribution model formed by two intersecting disks -the Gould Belt (GB) and the Local Galactic Disk (LGD)- defined by their fundamental geometric parameters. Then

M. -R. L. Cioni, L. Girardi, P. Marigo, H. J. Habing

This article compares the Ks magnitude distribution of Small Magellanic Cloud asymptotic giant branch stars obtained from the DENIS and 2MASS data with theoretical distributions. Theoretical Ks magnitude distributions have been constructed using up-to-date stellar evolution calculations for low and intermediate-mass stars, and in particular for thermally pul

A. Belloche, P. Hennebelle, P. Andre

The onset of gravitational collapse in cluster-forming clouds is still poorly known. Our goal is to use the Class 0 protostar IRAS 4A, which is undergoing collapse in the active molecular cloud NGC 1333, to set constraints on this process. In particular we want to measure the mass infall rate and investigate whether the collapse could have been triggered by

Michael Stamatikos, David Band

We describe the theoretical modeling and analysis techniques associated with a preliminary search for correlated neutrino emission from GRB980703a, which triggered the Burst and Transient Source Experiment (BATSE GRB trigger 6891), using archived data from the Antarctic Muon and Neutrino Detector Array (AMANDA-B10). Under the assumption of associated hadroni

Y. Bai, G. Xiao, Z. Cao

Cosmic Ray Tau Neutrino Telescopes (CRTNT) using for sub-EeV cosmic ray measurement is discussed. Performances of a stereoscope configuration with a tower of those telescopes plus two side-triggers are studied. This is done by using a detailed detector simulation driven by Corsika. Detector aperture as a function of shower energy above 10^17 eV is calculated

Y. B. Nian, J. Strozier, N. J. Wu, X. Chen

Electric pulse induced resistance (EPIR) switching hysteresis loops for Pr0.7Ca0.7MnO3 (PCMO) perovskite oxide films were found to exhibit an additional sharp &#34;shuttle peak&#34; around the negative pulse maximum for films deposited in an oxygen deficient ambient. The device resistance hysteresis loop consists of stable high resistance and low resistance

Pawel Horodecki, Remigiusz Augusiak

It is proven that recently introduced states with perfectly secure bits of cryptographic key (private states representing secure bit) [K. Horodecki et al., Phys. Rev. Lett. 94, 160502 (2005)] as well as its multipartite and higher dimension generalizations always represent distillable entanglement. The corresponding lower bounds on distillable entanglement a

P. D. Mininni, D. C. Montgomery

We present a computational method to solve the magnetohydrodynamic equations in spherical geometry. The technique is fully nonlinear and wholly spectral, and uses an expansion basis that is adapted to the geometry: Chandrasekhar-Kendall vector eigenfunctions of the curl. The resulting lower spatial resolution is somewhat offset by being able to build all the

Martin Hairer, Jonathan C. Mattingly

We develop a general method to prove the existence of spectral gaps for Markov semigroups on Banach spaces. Unlike most previous work, the type of norm we consider for this analysis is neither a weighted supremum norm nor an $Ł^p$-type norm, but involves the derivative of the observable as well and hence can be seen as a type of 1-Wasserstein distance. This

Lorenza Viola, Lea F. Santos

The need for strategies able to accurately manipulate quantum dynamics is ubiquitous in quantum control and quantum information processing. We investigate two scenarios where randomized dynamical decoupling techniques become more advantageous with respect to standard deterministic methods in switching off unwanted dynamical evolution in a closed quantum syst

R. Ali Vanderveld, Eanna E. Flanagan, Ira Wasserman

There has been much debate over whether or not one could explain the observed acceleration of the Universe with inhomogeneous cosmological models, such as the spherically-symmetric Lemaitre-Tolman-Bondi (LTB) models. It has been claimed that the central observer in these models can observe a local acceleration, which would contradict general theorems. We res

Umut Gursoy

Recently, a one-parameter deformation of the Maldacena-Nunez dual of the N=1 SYM theory was constructed in hep-th/0505100. According to the Lunin-Maldacena conjecture, the background is dual to pure N=1 SYM in the IR coupled to a KK sector whose dynamics is altered by a dipole deformation that is proportional to the deformation parameter gamma. Thus, the def

Lea F. Santos, Lorenza Viola

We demonstrate the advantages of randomization in coherent quantum dynamical control. For systems which are either time-varying or require decoupling cycles involving a large number of operations, we find that simple randomized protocols offer superior convergence and stability as compared to deterministic counterparts. In addition, we show how randomization

Xianwei Sha, R. E. Cohen

We compute the c/a lattice strain versus temperature for nonmagnetic hcp iron at high pressures using both first-principles linear response quasiharmonic calculations based on the full potential linear-muffin-tin-orbital (LMTO) method and the particle-in-cell (PIC) model for the vibrational partition function using a tight-binding total-energy method. The ti

S. Raghu, F. D. M. Haldane

&#34;Photonic crystals&#34; built with time-reversal-symmetry-breaking Faraday-effect media can exhibit &#34;chiral&#34; edge modes that propagate unidirectionally along boundaries across which the Faraday axis reverses. These modes are precise analogs of the electronic edge states of quantum Hall effect (QHE) systems, and are also immune to backscattering a

Peter Fischer, Daniel F. Litim

We study quantum gravity in more than four dimensions with renormalisation group methods. We find a non-trivial ultraviolet fixed point in the Einstein-Hilbert action. The fixed point connects with the perturbative infrared domain through finite renormalisation group trajectories. We show that our results for fixed points and related scaling exponents are st

T. Lappi, L. McLerran

We discuss high energy hadronic collisions within the theory of the Color Glass Condensate. We point out that the initial electric and magnetic fields produced in such collisions are longitudinal. This leads to a novel string like description of the collisions, and a large Chern-Simons charge density made immediately after the collision. The presence of the

Emanuele Berti

The observability of gravitational waves from supermassive and intermediate-mass black holes by the forecoming Laser Interferometer Space Antenna (LISA), and the physics we can learn from the observations, will depend on two basic factors: the event rates for massive black hole mergers occurring in the LISA best sensitivity window, and our theoretical knowle

N. Bastian, S. P. Goodwin

We present detailed luminosity profiles of the young massive clusters M82-F, NGC 1569-A, and NGC 1705-1 which show significant departures from equilibrium (King and EFF) profiles. We compare these profiles with those from N-body simulations of clusters which have undergone the rapid removal of a significant fraction of their mass due to gas expulsion. We sho

Richard B. Larson

The essential features of the stellar Initial Mass Function are, rather generally, (1) a peak at a mass of a few tenths of a solar mass, and (2) a power-law tail toward higher masses that is similar to the original Salpeter function. Recent work suggests that the IMF peak reflects a preferred scale of fragmentation associated with the transition from a cooli

Dongseok Kim, Jaeun Lee

Temperley-Lieb algebras have been generalized to sl(3) web spaces. Since a cubic bipartite planar graph with suitable directions on edges is a web, the quantum sl(3) invariants naturally extend to all cubic bipartite planar graphs. First we completely classify them as a connected sum of primes webs. We also provide a method to find all prime webs and exhibit

A. Capolupo, S. Capozziello, G. Vitiello

We show that the vacuum condensate due to neutrino mixing in quantum field theory (QFT) contributes to the dark energy budget of the universe which gives rise to the accelerated behavior of cosmic flow. The mechanism of neutrino mixing is therefore a possible candidate to contribute to the cosmological dark energy.

S. Jadach, B. F. L. Ward, S. A. Yost

We compare fully differential exact results for the virtual photon correction to single hard photon bremsstrahlung obtained using independent calculations, both for electron-positron annihilation at high-energy colliders and for radiative return applications. The results are compared using Monte Carlo evaluations of the matrix elements as well as by direct a

Pedro Freitas, David Krejcirik

The Dirichlet Laplacian in curved tubes of arbitrary constant cross-section rotating together with the Tang frame along a bounded curve in Euclidean spaces of arbitrary dimension is investigated in the limit when the volume of the cross-section diminishes. We show that spectral properties of the Laplacian are, in this limit, approximated well by those of the

Eliahu Levy

This note has two principal aims: to portray an essence of Non-Standard Analysis as a particular structure (which we call lim-rim), noting its interplay with the notion of ultrapower, and to present a construction of Non-Standard Analysis, viewed as a matter of mathematics, where the set *A of non-standard elements of a set A - &#34;the adjunction of all pos

A. Capella, E. G. Ferreiro

It has been shown that a final state interaction model, used to describe J/psi suppression, can also describe the fixed p_T suppression of the pi^0 (and charged pions) yield at all values of p_T, with a final state interaction cross-section sigma close to one milibarn. We propose an extension of the model to the pion motion in the transverse plane - which in

Nelson R. F. Braga, Hector L. Carrion, Cresus F. L. Godinho

We build up normal ordered products for fermionic open string coordinates consistent with boundary conditions. The results are obtained considering the presence of antisymmetric tensor fields. We find a discontinuity of the normal ordered products at string endpoints even in the absence of the background. We discuss how the energy momentum tensor also change

S. H. Castles

Particles moving on a radial ray with respect to a Schwarzschild mass are shown to have SU(1,1)/U(1) dynamical symmetry. This symmetry is used to identify a global time variable shared by all test particles moving on a radial ray. With this time variable, Hamilton&#39;s equations for particles on a radial ray have the form of the harmonic oscillator. The SU(

B. Ishwar, B. S. Kushvah

In this paper we have examined the linear stability of triangular equilibrium points in the generalised photogravitational restricted three body problem with Poynting-Robertson drag. We have found the position of triangular equilibrium points of our problem. The problem is generalised in the sense that smaller primary is supposed to be an oblate spheroid. Th

Nobuyuki Sakai, Ken-ichi Nakao, Hideki Ishihara, Makoto Kobayashi

To explore the possibility that an inflationary universe can be created out of a stable particle in the laboratory, we consider the classical and quantum dynamics of a magnetic monopole in the thin-shell approximation. Classically there are three types of solutions: stable, collapsing and inflating monopoles. We argue that the transition from a stable monopo

Benjamin Braun

M. Beck, J. De Loera, M. Develin, J. Pfeifle and R. Stanley found that the roots of the Ehrhart polynomial of a d-dimensional lattice polytope are bounded above in norm by 1+(d+1)!. We provide an improved bound which is quadratic in d and applies to a larger family of polynomials.

J. Kluson, Rashmi R. Nayak, Kamal L. Panigrahi

We study aspects of Dirichlet S-branes, which are defined as Dirichlet boundary condition on a time like embedding of open strings, in general backgrounds. By applying T-duality along an isometry of the unphysical dS2-branes in NS-NS supported AdS3-background, we find S0-brane. We also study the time dependent tachyon condensation on the unstable Dp-brane an

J. Ren, X. H. Meng

A generalized dynamical equation for the scale factor of the universe is proposed to describe the cosmological evolution, of which the $Λ$CDM model is a special case. It also provides a general example to show the equivalence of the modified equation of state (EOS) and a scalar field model. In the mathematical aspect, the EOS, the scalar field potential $V(ϕ

Amand Faessler, Th. Gutsche, M. A. Ivanov, J. G. Korner

The magnetic moments of ground state single, double and triple heavy baryons containing charm or bottom quarks are calculated in a relativistic three-quark model, which, in the heavy quark limit, is consistent with Heavy Quark Effective Theory and Heavy Hadron Chiral Perturbation Theory. The internal quark structure of baryons is modeled by baryonic three-qu

Michael Skeide

We construct a weak dilation of a not necessarily unital CP-semigroup to an E-semigroup acting on the adjointable operators of a Hilbert module with a unit vector. We construct the dilation in such a way that the dilating E-semigroup has a pre-assigned product system. Then, making use of the commutant of von Neumann correspondences, we apply the dilation the

G. Gaeta

We extend the Poincare&#39;-Lyapounov-Nekhoroshev theorem from torus actions and invariant tori to general (non-abelian) involutory systems of vector fields and general invariant manifolds.

Sergey Shadrin, Dimitri Zvonkine

In [5] I.P. Goulden, D.M. Jackson, and R. Vakil formulated a conjecture relating certain Hurwitz numbers (enumerating ramified coverings of the sphere) to the intersection theory on a conjectural Picard variety. We are going to use their formula to study the intersection theory on this variety (if it is ever to be constructed) by methods close to those of M.

Masanori Hanada, Hikaru Kawai, Yusuke Kimura

In a previous paper, we introduced a new interpretation of matrix models, in which any d-dimensional curved space can be realized in terms of d matrices, and the diffeomorphism and the local Lorentz symmetries are included in the ordinary unitary symmetry of the matrix model. Furthermore, we showed that the Einstein equation is naturally obtained, if we empl

H. X. Yang, Y. Xia, Y. G. Shi, H. F. Tian

Raman spectroscopy measurements have been performed on alpha-, beta-, gamma-NaxCoO2 phases differing in their stacking of CoO6 octahedra along the c-axis direction. The results demonstrate that, in general, there are five active phonons for gamma-Na0.75CoO2, two Raman active phonons for alpha-NaCoO2, and four Raman active phonons for beta-NaCoO2. We have als

M. Sadegh Movahed, F. Ghasemi, Sohrab Rahvar, M. Reza Rahimi Tabar

We investigate the statistical anisotropy and Gaussianity of temperature fluctuations of Cosmic Microwave Background radiation (CMB) data from {\it Wilkinson Microwave Anisotropy Probe} survey, using the multifractal detrended fluctuation analysis, rescaled range and scaled windowed variance methods. The multifractal detrended fluctuation analysis shows that

M. Ibe, K. -I. Izawa, Y. Shinbara, T. T. Yanagida

We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating temperature low enough to avoid the gravitino overproduction. We emphasize that all the phenomenological requirements from c

Dimitri Polyakov

Two-dimensional string theory is known to contain the set of discrete states that are the SU(2) multiplets generated by the lowering operator of the SU(2) current algebra.Their structure constants are defined by the area preserving diffeomorphisms in two dimensions. We show that the interaction of $d=2$ superstrings with the superconformal ghosts enlarges th

Pavel Chigansky

This note has been withdrawn by the author as the more complete result was recently proved by A.Quas and Y.Peres

Hyun Min Lee, Antonios Papazoglou

We study the scalar perturbation sector of the general axisymmetric warped Salam-Sezgin model with codimension-2 branes. We focus on the perturbations which mix with the dilaton. We show that the scalar fluctuations analysis can be reduced to studying two scalar modes of constant wavefunction, plus modes of non-constant wavefunction which obey a single Schro

Matthias Blau, Denis Frank, Sebastian Weiss

We analyse the effective potential of the scalar wave equation near generic space-time singularities of power-law type (Szekeres-Iyer metrics) and show that the effective potential exhibits a universal and scale invariant leading x^{-2} inverse square behaviour in the ``tortoise coordinate&#39;&#39; x provided that the metrics satisfy the strict Dominant Ene

Yuji Koike, Junji Nagashima, Werner Vogelsang

We study the transverse-momentum distribution of hadrons produced in semi-inclusive deep-inelastic scattering (SIDIS). We consider cross sections for various combinations of polarizations of the initial lepton and nucleon or the produced hadron, for which we perform the resummation of large double-logarithmic perturbative corrections arising at small transve

Edward A. Baltz, Marco Battaglia, Michael E. Peskin, Tommer Wizansky

If the cosmic dark matter consists of weakly-interacting massive particles, these particles should be produced in reactions at the next generation of high-energy accelerators. Measurements at these accelerators can then be used to determine the microscopic properties of the dark matter. From this, we can predict the cosmic density, the annihilation cross sec

Xuguang Huang, Xuewen Hao, Pengfei Zhuang

The gravitational effect on the chiral phase structure at finite temperature and density is investigated in the framework of Nambu--Jona-Lasinio model in $D$-dimensional ultrastatic Einstein universe. In mean field approximation, the thermodynamic potential and the gap equation determining the curvature, temperature and density dependence of the chiral conde

Li Guo, William Y. Sit

In this paper, we prove results on enumerations of sets of Rota-Baxter words in a finite number of generators and a finite number of unary operators. Rota-Baxter words are words formed by concatenating generators and images of words under Rota-Baxter operators. Under suitable conditions, they form canonical bases of free Rota-Baxter algebras and are studied

Kazuyuki Fujii, Hiroshi Oike, Tatsuo Suzuki

The usual action of Yang-Mills theory is given by the quadratic form of curvatures of a principal G bundle defined on four dimensional manifolds. The non-linear generalization which is known as the Born-Infeld action has been given. In this paper we give another non-linear generalization on four dimensional manifolds and call it a universal Yang-Mills action

L. Blum, M. Arias

New small angle scattering experiments reveal new peaks in colloidal systems (S.H. Chen et al) in the structure function S(k), in a region that was inaccessible with older instruments. We propose here general closure of the Ornstein Zernike equation, that is the sum of an arbitrary number of yukawas, and that that will go well beyond the MSA . For this closu

C. G. Boehmer, T. Harko

We consider the astrophysical and cosmological implications of the existence of a minimum density and mass due to the presence of the cosmological constant. If there is a minimum length in nature, then there is an absolute minimum mass corresponding to a hypothetical particle with radius of the order of the Planck length. On the other hand, quantum mechanica

Amaro J. Rica da Silva, José P. S. Lemos

A geometric view of the possible outcomes of elastic collisions of two massive bodies is developed that integrates laboratory, center of mass, and relative body frames in a single diagram. From these diagrams all the scattering properties of binary collisions can be obtained. The particular case of gravitational scattering by a moving massive object correspo

Vladimir Gritsev, Ehud Altman, Eugene Demler, Anatoli Polkovnikov

We analyze interference experiments for a pair of independent one dimensional condensates of interacting bosonic atoms at zero temperature. We show that the distribution function of fringe amplitudes contains non-trivial information about non-local correlations within individual condensates and can be calculated explicitly using methods of conformal field th