May 2006 arXiv papers — page 40

Yingbin Liang, H. Vincent Poor

A discrete memoryless generalized multiple access channel (GMAC) with confidential messages is studied, where two users attempt to transmit common information to a destination and each user also has private (confidential) information intended for the destination. The two users are allowed to receive channel outputs, and hence may obtain the confidential info

Yong-Jihn Kim

We show that SIS Josephson junctions have a threshold resistance, above which the Josephson coupling and the supercurrents become extremely small, due to the shrinking of the Cooper pair size during the Josephson tunneling. Accordingly, the threshold resistance is smaller for higher Tc superconductors with small Cooper pair size and for the insulating barrie

I. Leyva, I. Sendiña-Nadal, J. A. Almendral, M. A. F. Sanjuán

Through the last years, different strategies to enhance synchronization in complex networks have been proposed. In this Letter, we show that the synchronization in a small-world network of attractively coupled non-identical neurons is strongly improved by adding a tiny fraction of phase-repulsive couplings. By a purely topological analysis that does not depe

A. Golub, T. Aono, Yigal Meir

Experimental investigations of current shot noise in quantum point contacts show a reduction of the noise near the 0.7 anomaly. It is demonstrated that such a reduction naturally arises in a model proposed recently to explain the characteristics of the 0.7 anomaly in quantum point contacts in terms of a quasi-bound state, due to the emergence of two conducti

Joaquin Fernandez, Angel J. Garcia-Adeva, R. Balda

We report the first observation of anti-Stokes laser-induced cooling in the Er^{3+}:KPb_{2}Cl_{5} crystal and in the Er^{3+}:CNBZn (CdF_{2}-CdCl_{2}-NaF-BaF_{2}-BaCl_{2}-ZnF_{2}) glass. The internal cooling efficiencies have been calculated by using photothermal deflection spectroscopy. Thermal scans acquired with an infrared thermal camera proved the bulk c

Ronan Lefort, Denis Morineau, Régis Guégan, Moréac Alain

Structural order parameters of a smectic liquid crystal confined into the columnar form of porous silicon are studied using neutron scattering and optical spectroscopic techniques. It is shown that both the translational and orientational anisotropic properties of the confined phase strongly couple to the one-dimensional character of the porous silicon matri

A. V. Savin, G. P. Tsironis, X. Zotos

We investigate the thermal conductivity of the classical Heisenberg spin chain coupled to a variety of phonon systems using a Green-Kubo approach as well as coupling to heat reservoirs. The decay of energy current correlations is power law or exponential, depending on the type of (an)harmonicity of the phonon system and the presence of a substrate. In partic

R. Hayn, P. Lombardo, K. Matho

We present the continued fraction method (CFM) as a new microscopic approximation to the spectral density of the Hubbard model in the correlated metal phase away from half filling. The quantity expanded as a continued fraction is the single particle Green function. Leading spectral moments are taken into account through a set of real expansion coefficients,

Stanislas Rohart, Cécile Raufast, Luc Favre, Estela Bernstein

We report on the magnetic properties of Co$\_x$Pt$\_{1-x}$ clusters embedded in various matrices. Using a careful analysis of magnetization curves and ZFC susceptibility measurements, we determine the clusters magnetic anisotropy energy (MAE) and separate the surface and volume contributions. By comparing different chemical compositions, we show that a small

Joerg Baumgartl, Jose Luis Arauz-Lara, Clemens Bechinger

It is general wisdom that likely charged colloidal particles repel each other when suspended in liquids. This is in perfect agreement with mean field theories being developed more than 60 years ago. Accordingly, it was a big surprise when several groups independently reported long-ranged attractive components in the pair potential U(r) of equally charged col

A. Villares Ferrer, A. O. Caldeira, C. Morais Smith

Using the functional-integral method we investigate the effective dynamics of a charged particle coupled to a set of two-level systems as a function of temperature and external electric field. The optical conductivity and the direct current (dc) resistivity induced by the reservoir are computed. Three different regimes are found depending on the two-level sy

Mendeli H. Vainstein, Ismael V. L. Costa, Rafael Morgado, Fernando A. Oliveira

We study the relaxation process in normal and anomalous diffusion regimes for systems described by a generalized Langevin equation (GLE). We demonstrate the existence of a very general correlation function which describes the relaxation phenomena. Such function is even; therefore, it cannot be an exponential or a stretched exponential. However, for a proper

R. I. Hynes, K. Horne, K. O'Brien, C. A. Haswell

We present the first high time-resolution simultaneous X-ray, ultraviolet, and optical observations of X-ray bursts in UY Vol, the optical counterpart of the low mass X-ray binary EXO 0748-676, obtained with RXTE, HST, and Gemini-S. Strong reprocessed signals are present in the ultraviolet (a factor of 4) and optical (a factor of 2.5). These signals are lagg

Rahul Shetty, Eve C. Ostriker

We investigate the formation of substructure in spiral galaxies using global MHD simulations, including gas self-gravity. Our models extend previous local models by Kim and Ostriker (2002) by including the full effects of curvilinear coordinates, a realistic log-spiral perturbation, self-gravitational contribution from 5 radial wavelengths of the spiral shoc

Michael Loewenstein

The nature of star formation and Type Ia supernovae (SNIa) in galaxies in the field and in rich galaxy clusters are contrasted by juxtaposing the build-up of heavy metals in the universe inferred from observed star formation and supernovae rate histories with data on the evolution of Fe abundances in the intracluster medium (ICM). Models for the chemical evo

G. Burbidge, E. M. Burbidge, H. C. Arp, W. M. Napier

It is shown that all of the 32 point X-ray sources which lie within about 10' of the centre of nearby galaxies, and which have so far been optically identified are high redshift objects - AGN or QSOs. Thus the surface density of these QSOs p similar or equal to 0.1 per square arc minute. Some of them were originally discovered as X-ray sources and classi

Hector G. Arce, Anneila I. Sargent

We present multi-line and continuum observations of the circumstellar environment within 10^4 AU of a sample of protostars to investigate how the effects of outflows on their immediate environment changes over time. 12CO(1-0) emission probes the high-velocity molecular outflows near the protostars and demonstrate that the outflow opening angle widens as the

G. I. Ogilvie, S. H. Lubow

The migration of a planet through a gaseous disc causes the locations of their resonant interactions to drift and can alter the torques exerted between the planet and the disc. We analyse the time-dependent dynamics of a non-coorbital corotation resonance under these circumstances. The ratio of the resonant torque in a steady state to the value given by Gold

John J. Cowan, James E. Lawler, Christopher Sneden, E. A. Den Hartog

Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy -- the progenitors of the halo stars -- responsible for neutron-capture syn

Sean N. Raymond

Gas giant planets are far easier than terrestrial planets to detect around other stars, and are thought to form much more quickly than terrestrial planets. Thus, in systems with giant planets, the late stages of terrestrial planet formation are strongly affected by the giant planets' dynamical presence. Observations of giant planet orbits may therefore c

Tuomas Savolainen, Kaj Wiik, Esko Valtaoja, Matthias Kadler

We report the discovery of an extremely curved jet in the radio-loud quasar PKS2136+141. Multi-frequency Very Long Baseline Array (VLBA) images show a bending jet making a turn-around of 210 degrees in the plane of the sky, which is, to our knowledge, the largest ever observed change in the position angle of an astrophysical jet. Images taken at six differen

Jonathan E. Grindlay

We review new Chandra and HST observations of the core collapsed cluster NGC 6397 as a guide to understanding the compact binary (CB) populations in core collapse globulars. New cataclysmic variables (CVs) and main sequence chromospherically active binaries (ABs) have been identified, enabling a larger sample for comparison of the Lx, Fx/Fv and X-ray vs. opt

Dean E. McLaughlin, Roeland P. van der Marel

[Abridged]: We present a database of structural and dynamical properties for 153 spatially resolved star clusters (50 "young massive clusters" and 103 old globulars) in the Milky Way, the Large and Small Magellanic Clouds, and the Fornax dwarf spheroidal. This database complements and extends others in the literature, such as those of Harris, and Mac

M. Josefa Perez, Patricia B. Tissera, Cecilia Scannapieco, Diego G. Lambas

We perform an statistical analysis of galaxies in pairs in a Lambda-CDM scenario by using the chemical GADGET-2 of Scannapieco et al. (2005) in order to study the effects of galaxy interactions on colours and metallicities. We find that galaxy-galaxy interactions can produce a bimodal colour distribution with galaxies with significant recent star formation a

L. Miller, T. J. Turner, J. N. Reeves, I. M. George

We investigate the link between ionised Fe X-ray line emission and continuum emission in the bright nearby AGN, Mrk 766. A new long (433 ks) XMM-Newton observation is analysed, together with archival data from 2000 and 2001. The contribution from ionised line emission is measured and its time variations on short (5-20 ks) timescales are correlated with the c

D. Muders, H. Hafok, F. Wyrowski, E. Polehampton

APECS is the distributed control system of the new Atacama Pathfinder EXperiment (APEX) telescope located on the Llano de Chajnantor at an altitude of 5107 m in the Atacama desert in northern Chile. APECS is based on Atacama Large Millimeter Array (ALMA) software and employs a modern, object-oriented design using the Common Object Request Broker Architecture

H. J. Rocha-Pinto, R. H. O. Rangel, G. F. Porto de Mello, G. A. Braganca

We studied the relationship between the average stellar abundance of several elements and the orbital evolution of stars in the neighbourhood of the Sun, using both observational data for 325 late-type dwarfs in a volume-complete sample and simulations of the orbital diffusion. Metallicities, ages, and initial position and velocities for the simulated stars

Charlotte Vastel, T. G. Phillips, P. Caselli, C. Ceccarelli

Deuterium enhancement of monodeuterated species has been recognized for more than 30 years as a result of the chemical fractionation that results from the difference in zero point energies of deuterated and hydrogenated molecules. The key reaction is the deuteron exchange in the reaction between HD, the reservoir of deuterium in dark interstellar clouds, and

Holger Baumgardt

Globular clusters are among the oldest objects in galaxies, and understanding the details of their formation and evolution can bring valuable insight into the early history of galaxies. This review summarises the current knowledge about the dissolution of star clusters and discusses the implications of star cluster dissolution for the evolution of the mass f

Nicolas Leprovost, Eun-Jin Kim

We provide a consistent theory of the tachocline confinement (or anisotropic momentum transport) within an hydrodynamical turbulence model. The goal is to explain helioseismological data, which show that the solar tachocline thickness is at most 5% of the solar radius, despite the fact that, due to radiative spreading, this transition layer should have thick

N. Menci, A. Fontana, E. Giallongo, A. Grazian

We investigate the effect of AGN feedback associated to the bright QSO phase onto the color distribution of galaxies from z=0 up to z=4. To this aim, we insert a blast-wave model of AGN feedback in our semi-analytic model of galaxy formation, which includes the growth of supermassive black holes and the AGN activity triggered by interactions of the host gala

J. D. McEwen, P. Vielva, M. P. Hobson, E. Martinez-Gonzalez

Using a directional spherical wavelet analysis we detect the integrated Sachs-Wolfe (ISW) effect, indicated by a positive correlation between the Wilkinson Microwave Anisotropy Probe (WMAP) and NRAO VLA Sky Survey (NVSS) data, at the 3.9 sigma level. In a flat universe the detection of the ISW effect provides direct and independent evidence for dark energy.

A. Milone, S. Villanova, L. R. Bedin, G. Piotto

In this paper we present a new, accurate determination of the three components of the absolute space velocity of the Galactic globular cluster NGC6397 (l 338d, b -12d). We used three HST/WFPC2 fields with multi-epoch observations to obtain astrometric measurements of objects in three different fields in this cluster. The identification of 33 background galax

Fedor V. Prigara

It is shown that the high- temperature phase transition in a plasma gives the mechanism of transition from the highly conductive state to the highly resistive state of a plasma in the `electric circuit' model of solar flares which was first introduced by H.Alfven and P.Carlqvist in 1967. With this addendum, the modern version of the electric circuit mode

Jonathan E. Grindlay

In this short introductory commentary on the paper (Hessels et al 2006, Science, 311, 1901) reporting the discovery of the shortest spin period millisecond pulsar (MSP) Ter5-ad in the globular cluster Terzan 5, I also point out a new explanation for possible minimum spin periods, P, of MSPs without requiring gravitational radiation (or other) slow-down torqu

A. G. Kuranov, K. A. Postnov

Population synthesis is used to model the number of neutron stars in globular clusters that are observed as LMXBs and millisecond PSRs. The dynamical interaction between binary and single stars in a GC are assumed to take place with a permanently replenished "background" of single stars whose density distribution keeps track with the cluster evolutio

G. J. Madsen, D. J. Frew, Q. A. Parker, R. J. Reynolds

Accurate emission line fluxes from planetary nebulae (PNe) provide important constraints on the nature of the final phases of stellar evolution. Large, evolved PNe may trace the latest stages of PN evolution, where material from the AGB wind is returned to the interstellar medium. However, the low surface brightness and spatially extended emission of large P

Jun-ichi Nakashima

The author presents the results of Berkeley-Illinois-Maryland (BIMA) array interferometric observations in the CO J=1-0 line toward X Her and EP Aqr, the semiregular pulsating stars with a composite CO line profile, and also reports finding of a disklike structure in X Her. In the CO spectrum both of X Her and EP Aqr, a composite profile including narrow and

Jonathan E. Grindlay

The exhilerating results from Swift in its first year of operations have opened a new era of exploration of the high energy universe. The surge to higher redshifts of the Gamma-ray bursts now imaged with increased sensitivity establishes them as viable cosmic probes of the early universe. Wide-field coded aperture imaging with solid-state pixel detectors (Cd

M. De Pasquale, D. Grupe, T. S. Poole, A. A. Breeveld

We present the results of X-ray and optical observations of GRB050712 performed by Swift. The X-ray lightcurve of this burst exhibits episodes of flares in the first 1000s, the same epoch at which the UVOT detected an optical counterpart. A shallow X-ray decay, with a decay slope of -0.73, followed and lasted ~70ks. This behaviour can be explained in terms o

Xingang Chen, Min-xin Huang, Shamit Kachru, Gary Shiu

We perform a general study of primordial scalar non-Gaussianities in single field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of the scalar field and its first derivative, and the sound speed is arbitrary. We find that under reasonable assumptions, the non-Gaussianity is completely determ

Brandon Carter, Lars Samuelsson

At densities below the neutron drip threshold, a purely elastic solid model (including, if necessary, a frozen-in magnetic field) can provide an adequate description of a neutron star crust, but at higher densities it will be necessary to allow for the penetration of the solid lattice by an independently moving current of superfluid neutrons. In order to do

Ahmed E. Ismail, Gary S. Grest, Mark J. Stevens

Capillary waves occurring at the liquid-vapor interface of water are studied using molecular dynamics simulations. In addition, the surface tension, determined thermodynamically from the difference in the normal and tangential pressure at the liquid-vapor interface, is compared for a number of standard three- and four-point water models. We study four three-

Elemer E Rosinger

It is shown for a simple ODE that it has many symmetry groups beyond its usual Lie group symmetries, when its generalized solutions are considered within the nowhere dense differential algebra of generalized functions.

Pascale Garaud, Douglas N. C. Lin

We construct a new set of self-consistent analytical disk models by taking into account both viscous and radiative sources of thermal energy. We analyze the non-isothermal structure of the disk across the mid-plane for optically thick disks, and use the standard two-temperature model in the case of optically thin disks. We deduce a set of general formula for

F. S. Navarra, M. Nielsen

New spectroscopy from the B factories, the advent of CLEO-c and the BES upgrade renewed the interest in charmonia. Among the new measurements, the state X(3872) has received special attention due to its unexpected properties. Its structure has been studied with different theoretical approaches, most of them being able to reproduce the measured mass. A furthe

Dmitriy M Palatnik

Suggested a non-linear, non-gauge invariant model of Maxwell equations, based on the Kaluza-Klein theory. The spectrum of elementary charges and masses is obtained.

Alexandru Buium, Santiago R. Simanca

We develop an arithmetic analogue of linear partial differential equations in two independent ``space-time'' variables. The spatial derivative is a Fermat quotient operator, while the time derivative is the usual derivation. This allows us to ``flow'' integers or, more generally, points on algebraic groups with coordinates in rings with arith

Li Gang, Ma Wen-Gan, Jiang Yi, Zhang Ren-You

We investigate the simileptonic OZI-forbidden annihilation decays $B^-_c \to η^{'}(η,π^0) l^- \barν$ for $l=μ,e$ in the perturbative QCD, and carry out a precise calculation without any approximation for the one-loop contributions, which involves integrals of 4- and 5-point loop functions. Our results show that the branching ratios of decays $B^-_c \to η

Subroto Mukerjee, Cenke Xu, J. E. Moore

The $s=1$ spinor Bose condensate at zero temperature supports ferromagnetic and polar phases that combine magnetic and superfluid ordering. We analyze the topological defects of the polar condensate, correcting previous studies, and show that the polar condensate in two dimensions is unstable at any finite temperature; instead there is a nematic or paired su

Gregory A. Fiete

We theoretically investigate the Fermi edge singularity in a spin incoherent Luttinger liquid. Both cases of finite and infinite core hole mass are explored, as well as the effect of a static external magnetic field of arbitrary strength. For a finite mass core hole the absorption edge behaves as $(ω-ω_{\rm th})^α/ \sqrt{|\ln(ω-ω_{\rm th})|}$ for frequencies

Francis Halzen, Dan Hooper

A number of experimental techniques are currently being deployed in an effort to make the first detection of ultra-high energy cosmic neutrinos. To accomplish this goal, techniques using radio and acoustic detectors are being developed, which are optimally designed for studying neutrinos with energies in the PeV-EeV range and above. Data from the AMANDA expe

Allan Greenleaf, Malabika Pramanik, Wan Tang

We obtain $L^2$ decay estimates in $λ$ for oscillatory integral operators whose phase functions are homogeneous polynomials of degree m and satisfy various genericity assumptions. The decay rates obtained are optimal in the case of (2+2)--dimensions for any m while, in higher dimensions, the result is sharp for m sufficiently large. The proof for large $m$ f

M. Marvan

Every orthonomic system of partial differential equations is known to possess a finite number of integrability conditions sufficient to ensure the validity of all. Herewith we offer an efficient algorithm to construct a sufficient set of integrability conditions free of redundancies.

Sean A. Hartnoll, S. Prem Kumar

We compute the circular Wilson loop of N=4 SYM theory at large N in the rank k symmetric and antisymmetric tensor representations. Using a quadratic Hermitian matrix model we obtain expressions for all values of the 't Hooft coupling. At large and small couplings we give explicit formulae and reproduce supergravity results from both D3 and D5 branes with

Mei-Yin Chou, Steven R. Majewski, Katia Cunha, Verne V. Smith

We present reliable measurements of the metallicity distribution function (MDF) at different points along the tidal stream of the Sagittarius (Sgr) dwarf spheroidal (dSph) galaxy, based on high resolution, echelle spectroscopy of candidate M giant members of the Sgr system. The Sgr MDF is found to evolve significantly from a median [Fe/H] ~-0.4 in the core t

J. Schlappa, C. Schuessler-Langeheine, C. F. Chang, H. Ott

Using soft-x-ray diffraction at the site-specific resonances in the Fe L23 edge, we find clear evidence for orbital and charge ordering in magnetite below the Verwey transition. The spectra show directly that the (001/2) diffraction peak (in cubic notation) is caused by t2g orbital ordering at octahedral Fe2+ sites and the (001) by a spatial modulation of th

Ashwin Nayak, Pranab Sen

In this note, we characterize the form of an invertible quantum operation, i.e., a completely positive trace preserving linear transformation (a CPTP map) whose inverse is also a CPTP map. The precise form of such maps becomes important in contexts such as self-testing and encryption. We show that these maps correspond to applying a unitary transformation to

Waldyr A. Rodrigues, Quintino A. G. de Souza, Roldao da Rocha

In this paper using a Clifford bundle formalism we examine (a): the strong conditions for existence of conservation laws involving only the energy-momentum and angular momentum of the matter fields on a general Riemann-Cartan spacetime and also in the particular cases of Lorentzian and teleparallel spacetimes and (b): the conditions for the existence of cons

Steffen Koenig, Bin Zhu

We put cluster tilting in ageneral framework by showing that any quotient of a triangulated category modulo a tilting subcategory (that is, a maximal one-orthogonal subcategory) carries an abelian structure. These abelian quotients turn out to be module categories of Goreisten algebras of dimension at most one.

G. Galletta, G. Rodighiero, D. Bettoni, M. Moles

CONTEXT.The mass assembly is believed to be the dominant process of early galaxy formation. This mechanism of galaxy building can proceed either by repeated major mergers with other systems, or by means of accretion of matter from the surrounding regions. AIMS.In this paper we compare the properties of local disk galaxies that appear isolated, i.e. not tidal

David Chandler, Juan P. Garrahan, Robert L. Jack, Lutz Maibaum

Dynamical four-point susceptibilities measure the extent of spatial correlations in the dynamics of glass forming systems. We show how these susceptibilities depend on the length scales that necessarily form part of their definition. The behaviour of these susceptibilities is estimated by means of an analysis in terms of renewal processes within the context

Prosenjit Bose, Vida Dujmović, Danny Krizanc, Stefan Langerman

A graph G is a 2-tree if G=K_3, or G has a vertex v of degree 2, whose neighbours are adjacent, and Gǐs a 2-tree. A characterization of the degree sequences of 2-trees is given. This characterization yields a linear-time algorithm for recognizing and realizing degree sequences of 2-trees.

Giacomo Aletti

Given a strongly stationary Markov chain and a finite set of stopping rules, we prove the existence of a polynomial algorithm which projects the Markov chain onto a minimal Markov chain without redundant information. Markov complexity is hence defined and tested on some classical problems.

Giacomo Aletti, Giovanni Naldi, Giuseppe Toscani

We study certain nonlinear continuous models of opinion formation derived from a kinetic description involving exchange of opinion between individual agents. These models imply that the only possible final opinions are the extremal ones, and are similar to models of pure drift in magnetization. Both analytical and numerical methods allow to recover the final

Rouzbeh Allahverdi, Juan Garcia-Bellido, Kari Enqvist, Anupam Mazumdar

We argue that all the necessary ingredients for successful inflation are present in the flat directions of the Minimally Supersymmetric Standard Model. We show that out of many gauge invariant combinations of squarks, sleptons and Higgses, there are two directions, ${\bf LLe}$, and ${\bf udd}$, which are promising candidates for the inflaton. The model predi

A. Sheykhi, N. Riazi, M. H. Mahzoon

We construct some classes of electrically charged, static and spherically symmetric black hole solutions of the four-dimensional Einstein-Born-Infeld-dilaton gravity in the absence and presence of Liouville-type potential for the dilaton field and investigate their properties. These solutions are neither asymptotically flat nor (anti)-de Sitter. We show that

A. Sheykhi, N. Riazi

We consider charged black holes with curved horizons, in five dimensional dilaton gravity in the presence of Liouville-type potential for the dilaton field. We show how, by solving a pair of coupled differential equations, infinitesimally small angular momentum can be added to these static solutions to obtain charged rotating dilaton black hole solutions. In

Philippe Gaborit, Gilles Zemor

We consider the problem of constructing dense lattices of R^n with a given automorphism group. We exhibit a family of such lattices of density at least cn/2^n, which matches, up to a multiplicative constant, the best known density of a lattice packing. For an infinite sequence of dimensions n, we exhibit a finite set of lattices that come with an automorphis

Cristina Volpe

Neutrino physics is traversing an exciting period, after the important discovery that neutrinos are massive particles, that has implications from high-energy physics to cosmology. A new method for the production of intense and pure neutrino beams has been proposed recently: the ``beta-beam''. It exploits boosted radioactive ions decaying through beta

Luis Alvarez-Gaume, Pallab Basu, Marcos Marino, Spenta R. Wadia

In this paper we discuss the blackhole-string transition of the small Schwarzschild blackhole of $AdS_5 \times S^5$ using the AdS/CFT correspondence at finite temperature. The finite temperature gauge theory effective action, at weak {\it and} strong coupling, can be expressed entirely in terms of constant Polyakov lines which are $SU (N)$ matrices. In showi

S. T. Surzhikov

Time-accurate simulation of gas dynamic structures resulting in viscous, heat conducting and radiating gas flows through localized heat release areas is performed. Cases of intensive heat release in to air at atmospheric pressure are investigated, whereby the gas is heated up to temperatures 3000-20000 K, so that local differences of density reach tens and h

Paul Balmer, Giordano Favi

We discuss gluing of objects and gluing of morphisms in tensor triangulated categories. We illustrate the results by producing, among other things, a Mayer-Vietoris exact sequence involving Picard groups.

Eckart Viehweg

Let M be the moduli scheme of canonically polarized manifolds with Hilbert polynomial h. We construct for a given finite set I of natural numbers m>1 with h(m)>0 a projective compactification M' of the reduced scheme underlying M such that the ample invertible sheaf L corresponding to the determinant of the direct image of the m-th power of the relative

E. Athanassoula, Rachael Lynn Beaton

The inclination of M31 is too close to edge-on for a bar component to be easily recognised and is not sufficiently edge-on for a boxy/peanut bulge to protrude clearly out of the equatorial plane. Nevertheless, a sufficient number of clues allow us to argue that this galaxy is barred. We use fully self-consistent N-body simulations of barred galaxies and comp

M. Campisi, G. B. Bagci

We show that Tsallis ensemble of power-law distributions provides a mechanical model of nonextensive equilibrium thermodynamics for small interacting Hamiltonian systems, i.e., using Boltzmann's original nomenclature, we prove that it is an exact orthode. This means that the heat differential admits the inverse average kinetic energy as an integrating fa

Armen Sedrakian, Herbert Müther, Artur Polls

The thermodynamic functions of a Fermi gas with spin population imbalance are studied in the temperature-asymmetry plane in the BCS limit. The low temperature domain is characterized by anomalous enhancement of the entropy and the specific heat above their values in the unpaired state, decrease of the gap and eventual unpairing phase transition as the temper

Shin'ichi Nojiri, Sergei D. Odintsov, M. Sami

In this paper we investigate the cosmological effects of modified gravity with string curvature corrections added to Einstein-Hilbert action in the presence of a dynamically evolving scalar field coupled to Riemann invariants. The scenario exhibits several features of cosmological interest for late universe. It is shown that higher order stringy corrections

Jorge Berger

Many analyses based on the time-dependent Ginzburg--Landau model are not consistent with statistical mechanics, because thermal fluctuations are not taken correctly into account. We use the fluctuation-dissipation theorem in order to establish the appropriate size of the Langevin terms, and thus ensure the required consistency. Fluctuations of the electromag

Hans-Christian Graf von Bothmer, Oliver Labs, Josef Schicho, Christiaan van de Woestijne

Over a field of characteristic zero, it is clear that a polynomial of the form (X-a)^d has a non-trivial common factor with each of its d-1 first derivatives. The converse has been conjectured by Casas-Alvero. Up to now there have only been some computational verifications for small degrees d. In this paper the conjecture is proved in the case where the degr

Peter Schneider, Martin Kilbinger

Aims. One of the main probes for systematic errors in the cosmic shear signal are the division of the shear field into E- and B-mode shear, where gravitational lensing only produces the former. As shown in a recent note, all currently used E-/B-mode separation methods for the shear correlation functions xi_pm require them to be measured to arbitrarily small

Heinz-Peter Breuer

We develop a strong and computationally simple entanglement criterion. The criterion is based on an elementary positive map Phi which operates on state spaces with even dimension N >= 4. It is shown that Phi detects many entangled states with positive partial transposition (PPT) and that it leads to a class of optimal entanglement witnesses. This implies tha

Bhag C. Chauhan, Marco Picariello, Joao Pulido, Emilio Torrente-Lujan

The complementarity between the quark and lepton mixing matrices is shown to provide a robust prediction for the neutrino mixing angle $θ_{13}^{PMNS}$. We obtain this prediction by first showing that the matrix $V_M$, product of the CKM and PMNS mixing matrices, may have a zero (1,3) entry which is favored by experimental data. Hence models with bimaximal or

G. Bijani, N. Hamedani Radja, F. Mohammad-Rafiee, M. R. Ejtehadi

Effect of bending anisotropy on a planar DNA loop, using energy minimization and neglecting entropic effects, is studied. We show that the anisotropy results in polygonal shape of the loop and increasing the anisotropy makes the edges sharper. Calculating the energy of such a loop lets us to find effective persistence length as the geometrical mean of hard a

A. Bhagwat, R. Wyss, W. Satula, J. Meng

The spin-orbit (SO) interaction, emerging naturally from the Relativistic Mean Field (RMF) theory is examined critically in the light of the recently measured excitation energy differences between the terminating states built on two different configurations for nuclei belonging to the lower pf shell. The calculations are carried out using the cranked RMF fra

Toshiaki Tanaka

In our previous work, we proposed a mathematical framework for PT-symmetric quantum theory, and in particular constructed a Krein space in which PT-symmetric operators would naturally act. In this work, we explore and discuss various general consequences and aspects of the theory defined in the Krein space, not only spectral property and PT symmetry breaking

Arthur Bartels, David Rosenthal

It is proved that the assembly maps in algebraic K- and L-theory with respect to the family of finite subgroups is injective for groups with finite asymptotic dimension that admit a finite model for the classifying space for proper actions. The result also applies to certain groups that admit only a finite dimensional model for this space. In particular, it

S. A. Moiseev

A new protocol of the optical quantum memory based on the resonant interactions of the multi atomic system with a cavity light mode is proposed. The quantum memory is realized using a controllable inversion of the inhomogeneous broadening of the resonant atomic transition and impact interaction (on request) of additional short 2 - laser pulse resonant to an

Xavier Calmet

In this paper we describe how to implement symmetries on a canonical noncommutative spacetime. We focus on noncommutative Lorentz transformations. We then discuss the structure of the light cone on a canonical noncommutative spacetime and show that field theories formulated on these spaces do not violate mircocausality.

Javier Lopez Pena, Florin Panaite, Freddy Van Oystaeyen

We introduce the concept of pseudotwistor (with particular cases called twistor and braided twistor) for an algebra $(A, μ, u)$ in a monoidal category, as a morphism $T:A\otimes A\to A\otimes A$ satisfying a list of axioms ensuring that $(A, μ\circ T, u)$ is also an algebra in the category. This concept provides a unifying framework for various deformed (or

Tim Schmiedl, Udo Seifert

For chemical reaction networks described by a master equation, we define energy and entropy on a stochastic trajectory and develop a consistent nonequilibrium thermodynamic description along a single stochastic trajectory of reaction events. A first-law like energy balance relates internal energy, applied (chemical) work and dissipated heat for every single

Takaaki Nomura, Joe Sato, Takashi Shimomura

Electron capture processes are important in the search for new physics. In this context, a high capture rate is desired. We investigate the possibility of enhancing the electron capture rate by irradiating laser beam to ''atom''. The possibility of such enhancement can be understood as a consequence of an enhancement of the electron wave func

Sivaramakrishnan Sivasubramanian

We give a Cayley type formula to count the number of spanning trees in the complete r-uniform hypergraph for all r >= 3. Similar to the bijection between spanning trees in complete graphs and Parking functions, we derive a bijection from spanning trees of the complete (r+1)-uniform hypergraph which arise from a fixed r-perfect matching and r-Parking function

Marek Zukowski

This is an essay-review on a recently re-issued book of John Bell "Speakable and Unspeakable in Quantum Mechanics". The discussion concentrates around the Bell Theorem, its assumptions, consequences and frequent overinterpretations.

K G Arun

Laser Interferometer Space Antenna (LISA) will routinely observe coalescences of supermassive black hole (BH) binaries up to very high redshifts. LISA can measure mass parameters of such coalescences to a relative accuracy of $10^{-4}-10^{-6}$, for sources at a distance of 3 Gpc. The problem of parameter estimation of massive nonspinning binary black holes u

Takao Suyama

We construct a class of CFT's which describe space-dependent closed string tachyon backgrounds, as the IR limit of GLSM's in which the FI-parameter is promoted to a superfield. Whole process of tachyon condensation is described by a single CFT. We apply this construction to several examples, in which target space is deformed drastically, and the dila

Hideki Maeda, Naresh Dadhich

We obtain a new exact black-hole solution in Einstein-Gauss-Bonnet gravity with a cosmological constant which bears a specific relation to the Gauss-Bonnet coupling constant. The spacetime is a product of the usual 4-dimensional manifold with a $(n-4)$-dimensional space of constant negative curvature, i.e., its topology is locally ${\ma M}^n \approx {\ma M}^

Hideki Ishihara, Masashi Kimura, Ken Matsuno, Shinya Tomizawa

We construct the Kaluza-Klein multi-black hole solutions on the Gibbons-Hawking multi-instanton space in the five-dimensional Einstein-Maxwell theory. We study geometric properties of the multi-black hole solutions. In particular, unlike the Gibbons-Hawking multi-instanton solutions, each nut-charge is able to take a different value due to the existence of b

S. Whitlock, B. V. Hall, T. Roach, R. Anderson

We report on the origin of fragmentation of ultracold atoms observed on a permanent magnetic film atom chip. A novel technique is used to characterize small spatial variations of the magnetic field near the film surface using radio frequency spectroscopy of the trapped atoms. Direct observations indicate the fragmentation is due to a corrugation of the magne

J. S. Lazendic, D. Dewey, N. S. Schulz, C. R. Canizares

We present high-resolution X-ray spectra from the young supernova remnant Cas A using a 70-ks observation taken by the Chandra High Energy Transmission Grating Spectrometer (HETGS). Line emission, dominated by Si and S ions, is used for high-resolution spectral analysis of many bright, narrow regions of Cas A to examine their kinematics and plasma state. The