October 2006 arXiv papers — page 25

A. Andreone, G. Cifariello, E. Di Gennaro, G. Lamura

The linear and nonlinear response to a microwave electromagnetic field of two c-axis oriented polycrystalline samples of the newly discovered superconductor CaC6 (Tc = 11.5 K) is studied in the superconducting state down to 2 K. The surface resistance Rs and the third order intermodulation distortion, arising from a two-tone excitation, have been measured as

R. Khasanov, A. Shengelaya, D Di Castro, D. G. Eshchenko

The magnetic field dependence of the oxygen-isotope (^{16}O/^{18}O) effect (OIE) on the in-plane magnetic field penetration depth λ_{ab} was studied in the hole-doped high-temperature cuprate superconductors YBa_2Cu_4O_8, Y_0.8Pr_0.2Ba_2Cu_3O_7-δ, and Y_0.7Pr_0.3Ba_2Cu_3O_7-δ. It was found that λ_ab for the ^{16}O substituted samples increases stronger with

Kazuhiko Kuroki, Shuhei Ohkubo, Takumi Nojima, Ryotaro Arita

We analyze the origin of the three dimensional (3D) magnetism observed in nonhydrated Na-rich Na$_x$CoO$_2$ within an itinerant spin picture using a 3D Hubbard model. The origin is identified as the 3D nesting between the inner and outer portions of the Fermi surface, which arise due to the local minimum structure of the $a_{1g}$ band at the $Γ$-A line. The

H. W. Leite Alves

In this work, we present our theoretical results for the equation of state and the phonon dispersions of MnAs, as well as the Mn concentration dependence of both the lattice parameter and the phonon frequencies of the cubic GaMnAs alloys. The results are in good agreement with the experimental results whenever this comparison is possible. Based on the obtain

Haye Hinrichsen

In contrast to recent claims by Enss, Henkel, Picone, and Schollwoeck [J. Phys. A 37, 10479] it is shown that the critical autoresponse function of the 1+1-dimensional contact process is not in agreement with the predictions of local scale invariance.

Huijie Yang, Fangcui Zhao, Binghong Wang

The random matrix theory is used to bridge the network structures and the dynamical processes defined on them. We propose a possible dynamical mechanism for the enhancement effect of network structures on synchronization processes, based upon which a dynamic-based index of the synchronizability is introduced in the present paper.

D. L. Block, I. Puerari, G. G. Fazio, A. Stockton

The Triangulum Spiral Galaxy Messier 33 offers unique insights into the building of a galactic disk. We identify spectacular arcs of intermediate age (0.6 Gyr - 2 Gyr) stars in the low-metallicity outer disk. The northern arc spans approx. 120 degrees in azimuth and up to 5 arcmin in width. The arcs are located 2-3 disk scale lengths from the galaxy centre (

S. Silich, G. Tenorio-Tagle, C. Munoz-Tunon, J. Palous

Different hydrodynamic regimes for the gaseous outflows generated by multiple supernovae explosions and stellar winds occurring within compact and massive star clusters are discussed. It is shown that there exists the threshold energy that separates clusters whose outflows evolve in the quasi-adiabatic or radiative regime from those within which catastrophic

M. L. Milne, C. J. Pritchet, G. B. Poole, S. D. J. Gwyn

We present optical measurements of the faint end of the luminosity function in the core of the Coma cluster. Dwarf galaxies are detected down to a limiting magnitude of R approx. 25.75 in images taken with the Hubble Space Telescope. This represents the faintest determination of the Coma luminosity function to date. With the assumption that errors due to cos

Martin E. Pessah, Chi-kwan Chan, Dimitrios Psaltis

We develop a local model for the exponential growth and saturation of the Reynolds and Maxwell stresses in turbulent flows driven by the magnetorotational instability. We first derive equations that describe the effects of the instability on the growth and pumping of the stresses. We highlight the relevance of a new type of correlations that couples the dyna

Chris J. Willott, Alejo Martinez-Sansigre, Steve Rawlings

3C 318 is a z=1.574 radio-loud quasar. The small physical size of its radio jets indicate that these jets were triggered relatively recently. In addition to the ultraviolet continuum emission being reddened by dust, detections with IRAS and SCUBA show it to have an exceptionally high far-infrared luminosity. We present CO(2-1) observations of 3C 318 made wit

Oswaldo Toledano, Edmundo Moreno, Gloria Koenigsberger, R. Detmers

Stellar oscillations are excited in non-synchronously rotating stars in binary systems due to the tidal forces. Tangential components of the tides can drive a shear flow which behaves as a differentially forced rotating structure in a stratified outer medium. In this paper we show that our single-layer approximation for the calculation of the forced oscillat

Beverly J. Smith, C. Struck, M. Hancock, P. N. Appleton

We present Spitzer mid-infrared imaging of a sample of 35 tidally-distorted pre-merger interacting galaxy pairs selected from the Arp Atlas. We compare their global mid-infrared properties with those of normal galaxies from the SINGS Spitzer Legacy survey, and separate the disk emission from that of the tidal features. The [8.0 micron] - [24 micron], [3.6 mi

Fabio D. Barazza, Shardha Jogee, Irina Marinova

We present the first study of bars in the local Universe, based on the Sloan Digitized Sky Survey (SDSS). The large sample of ~5000 local galaxies provides the largest study to date of local bars and minimizes the effect of cosmic variance. The sample galaxies have M_g<=-18.5 mag and cover the redshift range 0.01<=z<0.04. We use a color cut in the color-magn

Albert A. Zijlstra

This paper reviews our knowledge on binary central stars of planetary nebulae and presents some personal opinions regarding their evolution. Three types of interactions are distinguished: type I, where the binary companion induces the mass loss; type II, where it shapes the mass loss but does not enhance it; type III, where a wide orbit causes the centre of

Ralf S. Klessen, Marco Spaans, Anne-Katharina Jappsen

Understanding the origin of stellar masses is a key problem in astrophysics. In the solar neighborhood, the mass distribution of stars follows a seemingly universal pattern. In the centre of the Milky Way, however, there are indications for strong deviations and the same may be true for the nuclei of distant starburst galaxies. Here we present the first nume

Ravi Kumar Kopparapu, Joel E. Tohline

Detached, inspiraling and semi-detached, mass-transferring double white dwarf (DWD) binary systems are both expected to be important sources for the proposed space-based gravitational-wave detector, LISA. The mass-radius relationship of individual white dwarf stars in combination with the constraints imposed by Roche geometries permit us to identify populati

P. G. Isar, S. Nehls, LOPES Collaboration

When Ultra High Energy Cosmic Rays interact with particles in the Earth&#39;s atmosphere, they produce a shower of secondary particles propagating toward the ground. LOPES-30 is an absolutely calibrated array of 30 dipole antennas investigating the radio emission from these showers in detail and clarifying if the technique is useful for largescale applicatio

Andreas Haungs, LOPES Collaboration

LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from Extensive Air Showers. Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by showers observed with KASCADE-Grande have been analyzed. We report about results of co

M. Firnstein, N. Przybilla

Massive BA-type supergiants are among the visually brightest stars in galaxies with active star formation. As such they are versatile tools for studies of stellar and galactochemical evolution. Moreover, they can act as distance indicators for the calibration of the cosmological distance scale. In the present work abundance patterns of the light elements hel

Alan B. Whiting, George K. T. Hau, Mike Irwin, Miguel Verdugo

We present the results of an all-sky, deep optical survey for faint Local Group dwarf galaxies. Candidate objects were selected from the second Palomar survey (POSS-II) and ESO/SRC survey plates and follow-up observations performed to determine whether they were indeed overlooked members of the Local Group. Only two galaxies (Antlia and Cetus) were discovere

Subhanjoy Mohanty, Ray Jayawardhana, Nuria Huelamo, Eric Mamajek

We present J-band imaging and H+K-band low-resolution spectroscopy of 2MASS1207-3932 AB, obtained with VLT NACO. For the putative planetary mass secondary, we find J = 20.0+/-0.2 mag. The HK spectra of both components imply low gravity, and a dusty atmosphere for the secondary. Comparisons to synthetic spectra yield Teff_A ~ 2550+/-150K, and Teff_B ~ 1600+/-

P. Haensel, J. L. Zdunik

We study possible impact of a softening of the equation of state by a phase transition, or appearance of hyperons, on the spin evolution of of isolated pulsars. Numerical simulations are performed using exact 2-D simulations in general relativity. The equation of state of dense matter at supranuclear densities is poorly known. Therefore, the accent is put on

Ralph Neuhaeuser, Andreas Seifahrt, Tristan Roell, Ana Bedalov

Many planet candidates have been detected by radial velocity variations of the primary star; they are planet candidates, because of the unknown orbit inclination. Detection of the wobble in the two other dimensions, to be measured by astrometry, would yield the inclination and, hence, true mass of the companions. We aim to show that planets can be confirmed

L. R. Bedin, G. Piotto, G. Carraro, I. R. King

We present improved values of the three components of the absolute space velocity of the open cluster NGC6791. One HST ACS/WFC field with two-epoch observations provides astrometric measurements of objects in a field containing the cluster center. Identification of 60 background galaxies with sharp nuclei allows us to determine an absolute reference point, a

P. Padovani

The &#34;blazar sequence&#34; posits that the most powerful BL Lacertae objects and flat-spectrum radio quasars should have relatively small synchrotron peak frequencies, nu_peak, and that the least powerful such objects should have the highest nu_peak values. This would have strong implications for our understanding of jet formation and physics and the poss

D. Heinzeller, W. J. Duschl, S. Mineshige, K. Ohsuga

Recently, the issue of the role of the Eddington limit in accretion discs became a matter of debate. While the classical (spherical) Eddington limit is certainly an over-simplification, it is not really clear how to treat it in a flattened structure like an accretion disc. We calculate the critical accretion rates and resulting disc luminosities for various

D. L. Block, F. Bournaud, F. Combes, R. Groess

The unusual morphology of the Andromeda Spiral (Messier 31, the closest spiral galaxy to the Milky Way) has long been an enigma. Although regarded for decades as showing little evidence of a violent history, M~31 has a well-known outer ring of star formation at a radius of 10 kpc whose center is offset from the galaxy nucleus. In addition, the outer galaxy d

James M. De Buizer

Thanks to the high spatial resolution afforded by 8-10m class telescopes, we are beginning to learn that some sources are extended in their mid-infrared emission because of dusty outflows or heated outflow cavity walls. Therefore one must be extremely careful in interpreting the nature of extended mid-infrared sources (i.e. just because it is extended does n

H. Bruntt, J. Southworth

We have begun a programme to obtain high-precision photometry of bright detached eclipsing binary (dEB) stars with the Wide field InfraRed Explorer (WIRE) satellite. Due to the small aperture of WIRE only stars brighter than V=6 can be observed. We are collecting data for about a dozen dEB targets and here we present preliminary results for three of them. We

H. Bruntt, J. C. Suarez, T. R. Bedding, D. L. Buzasi

We have analysed ground-based multi-colour Stromgren photometry and single-filter photometry from the star tracker on the WIRE satellite of the delta scuti star Epsilon Cephei. The ground-based data set consists of 16 nights of data collected over 164 days, while the satellite data are nearly continuous coverage of the star during 14 days. The spectral windo

Ray P. Norris, Jose Afonso, Phil N. Appleton, Brian J. Boyle

We present the first results from the Australia Telescope Large Area Survey (ATLAS), which consist of deep radio observations of a 3.7 square degree field surrounding the Chandra Deep Field South, largely coincident with the infrared Spitzer Wide-Area Extragalactic (SWIRE) Survey. We also list cross-identifications to infrared and optical photometry data fro

M. Briquet, S. Hubrig, M. Schoeller, P. De Cat

It is essential for the understanding of stellar structure models of high mass stars to explain why constant stars, non-pulsating chemically peculiar hot Bp stars and pulsating stars co-exist in the slowly pulsating B stars and beta Cephei instability strips. We have conducted a search for magnetic fields in the four Bp stars HD55522, HD105382, HD131120, and

Ofer Lahav, Andrew R Liddle

This is a review article for The Review of Particle Physics 2006 (aka the Particle Data Book). It forms a compact review of knowledge of the cosmological parameters as at May 2006. Topics included are Parametrizing the Universe; Extensions to the standard model; Probes; Bringing observations together; Outlook for the future.

Sanjit Mitra, Anand S. Sengupta, Tarun Souradeep

The measurements of the angular power spectrum of the Cosmic Microwave Background (CMB) anisotropy has proved crucial to the emergence of cosmology as a precision science in recent years. In this remarkable data rich period, the limitations to precision now arise from the the inability to account for finer systematic effects in data analysis. The non-circula

K. Abe

We report a preliminary study of the branching fractions and $q^2$ distributions of exclusive charmless semileptonic B decays, using events tagged by fully reconstructing one of the $B$ mesons in a hadronic decay mode. These results are obtained from a data sample that contains 535 $\times 10^6\ B\bar{B}$ pairs, collected near the $\Upsilon(4S)$ resonance wi

Jacob S. Christiansen, Erik Koelink

The symmetric Al-Salam--Chihara polynomials for $q>1$ are associated with an indeterminate moment problem. There is a self-adjoint second order difference operator on $\ell^2(\Z)$ to which these polynomials are eigenfunctions. We determine the spectral decomposition of this self-adjoint operator. This leads to a class of discrete orthogonality measures, whic

F. Reese Harvey, H. Blaine Lawson

We characterize the boundaries of positive holomorphic chains (with both compact and non-compact support) in an arbitrary complex manifold. We then consider a compact oriented real submanifold of dimension 2p-1 in a compact Kahler manifold X and address the question of which relative homology classes in H_{2p}(X,M;Z) are represented by positive holomorphic c

A. Rosado

We study the deep inelastic process $ν_τ + {\cal N} \to τ^{-} + X$ (with ${\cal N} \equiv (n+p)/2$ an isoscalar nucleon), in the context of the two Higgs doublet model type II (2HDM(II)). We discuss the contribution to the total cross section of diagrams, in which a charged Higgs boson is exchanged. We present results which show the strong dependence of such

Douglas M. Gingrich

We compare Monte Carlo event generators dedicated to simulating the production and decay of extra-dimensional black holes at the Large Hadron Collider.

Andrea Messina

The cross section for the inclusive production of W bosons in association with jets in ppbar collisions at sqrt(s)=1.96 TeV using the Collider Detector at Fermilab (CDF II) is presented. The measurement is based on an integrated luminosity of 320pb^-1, and includes events with up to 4 or more jets. In each jet multiplicity sample the differential and cumulat

David Alba, Horace W. Crater, Luca Lusanna

After a short review of the history and problems of relativistic Hamiltonian mechanics with action-at-a-distance inter-particle potentials, we study isolated two-body systems in the rest-frame instant form of dynamics. We give explicit expressions of the relevant relativistic notions of center of mass, we determine the generators of the Poincare&#39; group i

Jonathan C. Tan, Henrik Beuther, Fabian Walter, Eric G. Blackman

Supermassive black holes in giant elliptical galaxies are remarkably faint given their expected accretion rates. This motivates models of radiatively inefficient accretion, due to either ion-electron thermal decoupling, generation of outflows that inhibit accretion, or settling of gas to a gravitationally unstable disk that forms stars in preference to feedi

Bin Chen, Miao Li, Tower Wang, Yi Wang

We study a class of generalized inflation models in which the inflaton is coupled to the Ricci scalar by a general $f(ϕ, R)$ term. The scalar power spectrum, the spectral index, the running of the spectral index, the tensor mode spectrum and a new consistency relation of the model are calculated. We discuss in detail the issues of how to diagonize the couple

Daeseong Park, Jounghun Lee

Cosmic voids refer to the large empty regions in the universe with a very low number density of galaxies. Voids are likely to be severely disturbed by the tidal effect from the surrounding dark matter. We derive a completely analytic model for the void ellipticity distribution from physical principles. We use the spatial distribution of galaxies in a void as

Albert C. Fannjiang

Two-frequency radiative transfer (2f-RT) theory is developed for classical waves in random media. Depending on the ratio of the wavelength to the scale of medium fluctuation 2f-RT equation is either a Boltzmann-like integral equation with a complex-valued kernel or a Fokker-Planck-like differential equation with complex-valued coefficients in the phase space

Srdjan Ostojic, Thijs J. H. Vlugt, Bernard Nienhuis

Scaling properties of patterns formed by large contact forces are studied as a function of the applied shear stress, in two-dimensional static packings generated from the force network ensemble. An anisotropic finite-size-scaling analysis shows that the applied shear does not affect the universal scaling properties of these patterns, but simply induces diffe

Florentin Smarandache

Let&#39;s have $n$ points in the space such that the maximum distance between any of them is $a$. We prove that there exists a sphere of radius $r \leq a \frac{\sqrt(6)}{4}$ that contains in its interior or on its surface all these points. [This is a generalization of Jung&#39;s theorem that he designed for a plane.]

L. S. Geng, E. Oset, L. Roca, J. A. Oller

The axial vector meson $K_1(1270)$ was studied within the chiral unitary approach, where it was shown that it has a two-pole structure. We reanalyze the high-statistics WA3 experiment $K^- p\to K^-π^+π^- p$ at 63 GeV, which established the existence of both $K_1(1270)$ and $K_1(1400)$, and we show that it clearly favors our two-pole interpretation. We also r

A. A. Coley, W. C. Lim

We investigate the effect of dark energy on the limits on the shear anisotropy in spatially homogeneous Bianchi cosmological models obtained from measurements of the temperature anisotropies in the cosmic microwave background. We shall primarily assume that the dark energy is modelled by a cosmological constant. In general, we find that there are tighter bou

Harald Dorn, George Jorjadze

The paper is devoted to the Hamiltonian treatment of classical and quantum properties of Liouville field theory on a timelike strip in 2d Minkowski space. We give a complete description of classical solutions regular in the interior of the strip and obeying constant conformally invariant conditions on both boundaries. Depending on the values of the two bound

Saibal Ray, Farook Rahaman, Utpal Mukhopadhyay

Exact solutions of the Einstein field equations with cosmic string and space varying cosmological constant, viz., $Λ= Λ(r)$, in the energy-momentum tensors are presented. Three cases have been studied: where variable cosmological constant (1) has power law dependence, (2) is proportional to the string fluid density, and (3) is purely a constant. Some cases o

Yves Brihaye, Eugen Radu, D. H. Tchrakian

We consider particle-like and black holes solutions of the Einstein-Yang-Mills system with positive cosmological constant in d>4 spacetime dimensions. These configurations are spherically symmetric and present a cosmological horizon for a finite value of the radial coordinate, approaching asymptotically the de Sitter background. In the usual Yang--Mills case

G. Burgio, M. Fuhrmann, W. Kerler, M. Muller-Preussker

The deconfinement transition is studied close to the continuum limit of SO(3) lattice gauge theory. High barriers for tunnelling among different twist sectors causing loss of ergodicity for local update algorithms are circumvented by means of parallel tempering. We compute monopole and center vortex free energies both within the confining phase and through t

J. Bellorin, P. Meessen, T. Ortin

We classify the supersymmetric solutions of ungauged N=1 d=5 SUGRA coupled to vector multiplets and hypermultiplets. All the solutions can be seen as deformations of solutions with frozen hyperscalars. We show explicitly how the 5-dimensional Reissner-Nordstrom black hole is deformed when hyperscalars are living on SO(4,1)/SO(4) are turned on, reducing its s

V. A. Averchenko, A. P. Alodjants, S. M. Arakelian, S. N. Bagayev

A quantum model of Bose-Einstein condensation based on processes involving polaritons excited in an intracavity absorbing cell with resonance atoms, which is manifested in the spectral characteristics of the system, is considered. It is shown that the spectral &#39;condensation&#39; appears which is directly related to the degeneracy of a weakly interacting

S. Bernadotte, F. R. Klinkhamer

Simple models of a classical spacetime foam are considered, which consist of identical static defects embedded in Minkowski spacetime. Plane-wave solutions of the vacuum Maxwell equations with appropriate boundary conditions at the defect surfaces are obtained in the long-wavelength limit. The corresponding dispersion relations ω^2=ω^2(\vec{k}) are calculate

Karin Baur, Bethany Marsh

We show that the m-cluster category of type D_n is equivalent to a certain geometrically-defined category of arcs in a punctured regular nm-m+1-gon. This generalises a result of Schiffler for m=1. We use the notion of the mth power of a translation quiver to realise the m-cluster category in terms of the cluster category.

Klaus Fabricius

We construct a $Q$-matrix for the eight-vertex model at roots of unity for crossing parameter $η=2mK/L$ with odd $L$, a case for which the existing constructions do not work. The new $Q$-matrix $\Q$ depends as usual on the spectral parameter and also on a free parameter $t$. For $t=0$ $\Q$ has the standard properties. For $t\neq 0$, however, it does not comm

F. Rahaman, B. C. Bhui, A Ghosh, R. Mondal

The gravitational fields of vacuumless global and gauge strings have been investigated in the context of Einstein Cartan theory under the weak field assumption of the field equations. It has been shown that global string and gauge string can have only repulsive gravitational effect on a test particle.

Arindam Mitra

It is believed that quantum communication is not possible with a pure ensemble of states because quantum entropy of pure state is zero. This is indeed possible due to geometric consequence of entanglement.

M. Scala, B. Militello, A. Messina, J. Piilo

In this paper we provide a microscopic derivation of the master equation for the Jaynes-Cummings model with cavity losses. We single out both the differences with the phenomenological master equation used in the literature and the approximations under which the phenomenological model correctly describes the dynamics of the atom-cavity system. Some examples w

Alcides Garat

A new tetrad introduced within the framework of geometrodynamics for non-null electromagnetic fields allows for the geometrical analysis of the Lorentz force equation and its solutions in curved spacetimes. When expressed in terms of this new tetrad, the electromagnetic field displays explicitly maximum simplification, and the degrees of freedom are manifest

D. K. Gridnev, M. E. Garcia

In the framework of non-relativistic quantum mechanics and with the help of the Greens functions formalism we study the behavior of weakly bound states as they approach the continuum threshold. Through estimating the Green&#39;s function for positive potentials we derive rigorously the upper bound on the wave function, which helps to control its falloff. In

T. Lancaster, S. J. Blundell, P. J. Baker, D. Prabhakaran

We present the results of muon-spin relaxation ($μ^{+}$SR) measurements on the kagome staircase compounds Ni$_{3}$V$_{2}$O$_{8}$ and Co$_{3}$V$_{2}$O$_{8}$. The magnetic behavior of these materials may be described in terms of two inequivalent magnetic ion sites, known as spine sites and cross-tie sites. Our $μ^{+}$SR results allow us to probe each of these

P. Buonsante, V. Penna, A. Vezzani, P. B. Blakie

We show that a site-dependent mean-field approach captures the quantum phases of the disordered Bose-Hubbard model commonly adopted to describe ultracold bosons in random optical lattice potentials. The different phases, namely superfluid, Mott insulator, Bose-glass and -- at finite temperature -- normal fluid, are characterized by means of the superfluid an

Carlos T. Simpson

This is an expository account of Katz&#39;s middle convolution operation on local systems over ${\bf P}^1-\{q\_1,..., q\_n\}$. We describe the Betti and de Rham versions, and point out that they give isomorphisms between different moduli spaces of local systems, following Völklein, Dettweiler-Reiter, Haraoka-Yokoyama. Kostov&#39;s program for applying the Ka

Hans-Joachim Baues, Fernando Muro

The primary algebraic model of a ring spectrum is the ring of homotopy groups. We introduce the secondary model which has the structure of a secondary analogue of a ring. This new algebraic model determines Massey products and cup-one squares. As an application we obtain new derivations of the homotopy ring.

Ph. Brax, C. van de Bruck, A. C. Davis, Stephen C. Davis

We present a D-term hybrid inflation model, embedded in supergravity with moduli stabilisation. Its novel features allow us to overcome the serious challenges of combining D-term inflation and moduli fields within the same string-motivated theory. One salient point of the model is the positive definite uplifting D-term arising from the moduli stabilisation s

Yoav Tsori, Ludwik Leibler

When a liquid mixture is subjected to external electric fields, ionic screening leads to field gradients. We point out that if the mixture is initially in the homogeneous phase, this screening can bring about a robust phase-separation transition with two main features: (i) the phase separation is expected to occur in any electrode geometry, and (ii) the volt

S. Caenepeel, K. Janssen

We introduce partial (co)actions of a Hopf algebra $H$ on an algebra. To this end, we introduce first the notion of lax coring, generalizing Wisbauer&#39;s notion of weak coring. We also have the dual notion of lax ring. Several duality results are given, and we develop Galois theory for partial $H$-comodule algebras.

Izu Vaisman

We define integrable, big-isotropic structures on a manifold $M$ as subbundles $E\subseteq TM\oplus T^*M$ that are isotropic with respect to the natural, neutral metric (pairing) $g$ of $TM\oplus T^*M$ and are closed by Courant brackets (this also implies that $[E,E^{\perp_g}]\subseteq E^{\perp_g}$). We give the interpretation of such a structure by objects

Michele Frigerio

We consider thermal leptogenesis as the origin of the matter-antimatter asymmetry of the Universe. Some phenomenologically unpleasant features of the usual leptogenesis scenario are reviewed. We propose a minimal alternative, which makes use of a charged scalar $δ^+$, singlet under $SU(2)_L$. Such particle is contained in natural extensions of the Standard M

Sergey Khoroshkin, Stanislav Pakuliak, Vitaly Tarasov

In this paper we compare two constructions of weight functions (off-shell Bethe vectors) for the quantum affine algebra $U_q(\hat{\mathfrak{gl}}_N)$. The first construction comes from the algebraic nested Bethe ansatz. The second one is defined in terms of certain projections of products of Drinfeld currents. We show that two constructions give the same resu

Ye. S. Avotina, Yu. A. Kolesnichenko, A. F. Otte, J. M. van Ruitenbeek

The influence of a quantizing magnetic field $H$ to the conductance of a tunnel point contact in the presence of the single defect has been considered. We demonstrate that the conductance exhibits specific magneto-quantum oscillations, the amplitude and period of which depend on the distance between the contact and the defect. We show that a non-monotonic de

Muhammad Akashi, Noam Soker, Ehud Behar, John Blondin

We calculate the X-ray emission from both constant and time evolving shocked fast winds blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric numerical simulations with radiative cooling, we calculate the flow structure, and the X-ray temperature and luminosity of the hot bubble formed by the shocked

H. E. S. S. collaboration, :, F. A. Aharonian

The detection of gamma-rays from the source HESS J1745-290 in the Galactic Center (GC) region with the H.E.S.S. array of Cherenkov telescopes in 2004 is presented. After subtraction of the diffuse gamma-ray emission from the GC ridge, the source is compatible with a point-source with spatial extent less than 1.2&#39;(stat.) (95% CL). The measured energy spec

Aleksandar Mikovic

We explain how General Relativity with a cosmological constant arises as a broken symmetry phase of a BF theory. In particular we show how to treat de Sitter and anti-de Sitter cases simultaneously. This is then used to formulate a quantisation of General Relativity through a spin foam perturbation theory. We then briefly discuss how to calculate the effecti

Nicolas Fressengeas, Hervé Frezza-Buet

This paper shows how partial differential problems can be solved thanks to cellular computing and an adaptation of the Least Squares Finite Elements Method. As cellular computing can be implemented on distributed parallel architectures, this method allows the distribution of a resource demanding differential problem over a computer network.

D. V. Anghel, T. Kühn, Y. M. Galperin, M. Manninen

To describe the interaction of the two level systems (TLSs) of an amorphous solid with arbitrary strain fields, we introduce a generalization of the standard interaction Hamiltonian. In this new model, the interaction strength depends on the orientation of the TLS with respect to the strain field through a $6\times 6$ symmetric tensor of deformation potentia

C. Y. Hui, W. Becker

Using archival Chandra data we studied the X-ray emission properties of PSR B2224+65 and its environment. Albeit limited by photon statistics the spectral analysis suggests that the bulk of the emission from PSR B2224+65 is non-thermal. Fitting a power-law to the observed energy spectrum yields a photon index of $Γ=1.58^{+0.43}_{-0.33}$. The possible origin

Yong Zhang, Naihuan Jing, Mo-Lin Ge

The antisymmetric solution of the braided Yang--Baxter equation called the Bell matrix becomes interesting in quantum information theory because it can generate all Bell states from product states. In this paper, we study the quantum algebra through the FRT construction of the Bell matrix. In its four dimensional representations via the coproduct of its two

M R Setare

In this paper we study cosmological application of holographic dark energy density in the Brans-Dicke framework. We employ the holographic model of dark energy to obtain the equation of state for the holographic energy density in non-flat (closed) universe enclosed by the event horizon measured from the sphere of horizon named $L$. Our calculation show, taki

O. N. Prudnikov, A. V. Taichenachev, A. M. Tumaikin, V. I. Yudin

Generally, the conditions for deep sub-Doppler laser cooling do not match the conditions for the strong atomic localization that takes a place in deeper optical potential and, in consequence, leads to larger temperature. Moreover, for a given detuning in a deep optical potential the secular approximation which is usually used for quantum description of laser

T. Lancaster, S. J. Blundell, D. Andreica, M. Janoschek

The rare-earth ferroelectromagnet YMnO3 consists of weakly coupled triangular layers of S=2 spins. Below T_N ~ 70 K muon-spin relaxation data show two oscillatory relaxing signals due to magnetic order, with no relaxing signal resolvable (which would be expected for different coexisting spin distributions). The transition temperature T_N increases with appli

Hui Hu, Xia-Ji Liu, Peter D. Drummond

Based on the integrable Gaudin model and local density approximation, we discuss the phase structure of one-dimensional trapped Fermi gases with imbalanced spin populations for arbitrary attractive interactions. A phase separation state, with a polarized superfluid core immersed in an unpolarized superfluid shell, emerges below a critical spin polarization.

Richard Berkovits, Boris Altshuler

The conductance through a serial double dot structure for which the inter-dot tunneling is stronger than the tunneling to the leads is studied using the numerical density matrix renormalization group method and analytic arguments. When the dots are occupied by 1 or 3 electrons the usual Kondo peak is obtained. For the case in which 2 electrons occupy the mol

Georges Bouzerar

We propose a theory which allow to calculate the magnetic excitation spectrum in diluted ferromagnetic systems. The approach is rather general and based on the Self-Consistent local Random Phase Approximation in which disorder (dilution) and thermal fluctuations are properly treated. To illustrate its reliability and accuracy we calculate the magnetic excita

Krzysztof Pachucki

The $m α^6$ correction to energy is expressed in terms of an effective Hamiltonian $H^{(6)}$ for an arbitrary state of helium. Numerical calculations are performed for $n=2$ levels, and the previous result for the $2^3P$ centroid is corrected. While the resulting theoretical predictions for the ionization energy are in moderate agreement with experimental va

R. V. Harlander, D. R. T. Jones, P. Kant, L. Mihaila

Within the framework of QCD we compute renormalization constants for the strong coupling and the quark masses to four-loop order. We apply the DR-bar scheme and put special emphasis on the additional couplings which have to be taken into account. This concerns the epsilon-scalar--quark Yukawa coupling as well as the vertex containing four epsilon-scalars. Fo

Ying-Qiu Gu

The Einstein&#39;s mass-energy relation $E=mc^2$ is one of the most fundamental formulae in physics, but it has not been seriously tested by an elaborated experiment, and only some indirect evidences in nuclear reaction suggested that it holds to high precision. Manifestly, for a particle, different self potential leads to different energy-speed relation, wh

Chao-Hsi Chang, Jian-Ping Ma, Cong-Feng Qiao, Xing-Gang Wu

The effects of the intrinsic charm on the hadronic production of $Ξ_{cc}$ are studied. By taking reasonable intrinsic charm component into account, the change of the theoretical prediction on the production of $Ξ_{cc}$ for LHC and Tevatron is small, but in contrast it may enhance significantly for SELEX. The reason is that the collision energy at LHC and Tev

Wei Fang, H. Q. Lu, Z. G. Huang

We generally investigate the scalar field model with the lagrangian $L=F(X)-V(ϕ)$, which we call it {\it General Non-Canonical Scalar Field Model}. We find that it is a special square potential(with a negative minimum) that drives the linear field solution($ϕ=ϕ_0t$) while in K-essence model(with the lagrangian $L=-V(ϕ)F(X)$) the potential should be taken as

Yu Lan, Jihong Qin, Shiping Feng

Within the t-t&#39;-J model, the electron spectrum and quasiparticle dispersion in doped bilayer cuprates in the normal state are discussed by considering the bilayer interaction. It is shown that the bilayer interaction splits the electron spectrum of doped bilayer cuprates into the bonding and antibonding components around the $(π,0)$ point. The differenti

Vyacheslav M. Abramov

Under the assumption that the initial population size of a Galton-Watson branching process increases to infinity, the paper studies asymptotic behavior of the population size before extinction. More specifically, we establish asymptotic properties of the conditional moments (which are exactly defined in the paper).

Atsuo Kuniba, Reiho Sakamoto, Yasuhiko Yamada

We introduce ultradiscrete tau functions associated with rigged configurations for A^{(1)}_n. They satisfy an ultradiscrete version of the Hirota bilinear equation and play a role analogous to a corner transfer matrix for the box-ball system. As an application, we establish a piecewise linear formula for the Kerov-Kirillov-Reshetikhin bijection in the combin

Animesh Mukherjee, Monojit Choudhury, Anupam Basu, Niloy Ganguly

The sound inventories of the world&#39;s languages self-organize themselves giving rise to similar cross-linguistic patterns. In this work we attempt to capture this phenomenon of self-organization, which shapes the structure of the consonant inventories, through a complex network approach. For this purpose we define the occurrence and co-occurrence networks

Wenzhe Ma, Luhua Lai, Qi Ouyang, Chao Tang

Biomolecular networks have to perform their functions robustly. A robust function may have preferences in the topological structures of the underlying network. We carried out an exhaustive computational analysis on network topologies in relation to a patterning function in Drosophila embryogenesis. We found that while the vast majority of topologies can eith

Yan Li, Hui Jing, Ming-Sheng Zhan

We propose a simple scheme to generate an arbitrary photon-added coherent state of a travelling optical field by using only a set of degenerate parametric amplifiers and single-photon detectors. Particularly, when the single-photon-added coherent state (SPACS) is observed by following, e.g., the novel technique of Zavatta \emph{$et al.$} (Science 306, 660 (2

G. Chiribella, G. M. D&#39;Ariano, P. Perinotti

This paper collects miscellaneous results about the group SU(1,1) that are helpful in applications in quantum optics. Moreover, we derive two new results, the first is about the approximability of SU(1,1) elements by a finite set of elementary gates, and the second is about the regularization of group identities for tomographic purposes.