June 2007 arXiv papers — page 27

L. L. Salcedo

The heat kernel in curved space-time is computed to fourth order in a strict expansion in the number of covariant derivatives. The computation is made for arbitrary non abelian gauge and scalar fields and for the Riemann connection in the coordinate sector. The expressions obtained hold for arbitrary tensor representations of the matter field. Complete resul

S. Farkas, Z. Zimboras

We study the von Neumann entropy asymptotics of pure translation-invariant quasi-free states of d-dimensional fermionic systems. It is shown that the entropic area law is violated by all these states: apart from the trivial cases, the entropy of a cubic subsystem with edge length L cannot grow slower than L^{d-1}ln L. As for the upper bound of the entropy as

Ali Mostafazadeh

The quantum measurement axiom dictates that physical observables and in particular the Hamiltonian must be diagonalizable and have a real spectrum. For a time-independent Hamiltonian (with a discrete spectrum) these conditions ensure the existence of a positive-definite inner product that renders the Hamiltonian self-adjoint. Unlike for a time-independent Ha

Takahiro Mori, Hikaru Kawamura

Spatiotemporal correlations of the two-dimensional spring-block (Burridge-Knopoff) model of earthquakes are extensively studied by means of numerical computer simulations. The model is found to exhibit either ``subcritical'' or ``supercritical'' behavior, depending on the values of the model parameters. Transition between these regimes is eit

Aharon Levy

Exclusive rho0 electroproduction at HERA has been studied with the ZEUS detector, using 120 pb{-1} integrated luminosity, in the kinematic range of photon virtuality of 2 < Q2 < 160 GeV2, and gamma* p center-of-mass energy of 32 < W < 180 GeV. The results include the Q2 and W dependence of the gamma* p --> rho0 p cross section and the distribution of the squ

Jesper Pedersen, Christian Flindt, Niels Asger Mortensen, Antti-Pekka Jauho

We calculate the exchange coupling for a double dot system using a novel, numerically exact yet efficient technique, based on finite-element methods. Specifically, we evaluate the exchange coupling both for a quasi-one and a two-dimensional system, also including an applied magnetic field. Our numerical results provide a stringent test for standard approxima

P. R. Young, G. Del Zanna, H. E. Mason, K. P. Dere

Quiet Sun and active region spectra from the Hinode/EIS instrument are presented, and the strongest lines from different temperature regions discussed. A list of emission lines recommended to be included in EIS observation studies is presented based on analysis of blending and diagnostic potential using the CHIANTI atomic database. In addition we identify th

P. R. Young, G. Del Zanna, H. E. Mason, G. A. Doschek

Two types of active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at log T=5.4-5.8, allowing the temperature increase along the footpoints to be clearly seen. A density diagnostic of Mg VI

K. Morawetz M. Männel, M. Schreiber, P. Lipavský

The pole of the two-particle T-matrix including the influence of the surrounding medium is analyzed for an interacting Bose gas. The phase diagram of the Bose -Einstein condensation (BEC) depending on the temperature, density, scattering length, and momentum is derived from this pole. The critical momentum for the occurrence of superfluidity is obtained in t

Zakhar Kabluchko

Let $\{X_i,i=1,2,...\}$ be i.i.d. standard gaussian variables. Let $S_n=X_1+...+X_n$ be the sequence of partial sums and $$ L_n=\max_{0\leq i<j\leq n}\frac{S_j-S_i}{\sqrt{j-i}}. $$ We show that the distribution of $L_n$, appropriately normalized, converges as $n\to\infty$ to the Gumbel distribution. In some sense, the the random variable $L_n$, being the max

Mauro Antezza, Lev P. Pitaevskii, Sandro Stringari, Vitaly B. Svetovoy

We study the Casimir-Lifshitz interaction out of thermal equilibrium, with particular attention devoted to the surface-surface and surface-atom configurations. A systematic investigation of the contributions to the force coming from the propagating and evanescent components of the electromagnetic radiation is performed. The large distance behaviors of such i

Dumitru Astefanesei, Hossein Yavartanoo

We investigate the symmetries of the near horizon geometry of extremal stationary black holes in four dimensional Einstein gravity coupled to abelian gauge fields and neutral scalars. Careful consideration of the equations of motion and the boundary conditions at the horizon imply that the near horizon geometry has $SO(2,1)\times U(1)$ isometry. This complem

Amand Faessler, Thomas Gutsche, Valery E. Lyubovitskij, Igor T. Obukhovsky

We study the p(e,e&#39; pi+)n reaction in the framework of an effective Lagrangian approach including nucleon, pi and rho meson degrees of freedom and show the importance of the rho-meson t-pole contribution to sigmaT, the transverse part of cross section. We test two different field representations of the rho meson, vector and tensor, and find that the tens

Yuval Grossman, Yosef Nir, Jesse Thaler, Tomer Volansky

If the LHC experiments discover new particles that couple to the Standard Model fermions, then measurements by ATLAS and CMS can contribute to our understanding of the flavor puzzles. We demonstrate this statement by investigating a scenario where extra SU(2)-singlet down-type quarks are within the LHC reach. By measuring masses, production cross sections an

Christopher Tuffley

Given a knot K we may construct a group G_n(K) from the fundamental group of K by adjoining an nth root of the meridian that commutes with the corresponding longitude. These &#34;generalised knot groups&#34; were introduced independently by Wada and Kelly, and contain the fundamental group as a subgroup. The square knot SK and the granny knot GK are a well k

Wei Xue, Bin Chen, Yi Wang

We study the noncommutative inflation with a time-dependent noncommutativity between space and time. From the numerical analysis of power law inflation, there are clues that the CMB spectrum indicates a nonconstant noncommutative inflation. Then we extend our treatment to the inflation models with more general noncommutativity and find that the scalar pertur

Mikko Mottonen, Ville Pietila, Sami M. M. Virtanen

The formation of vortices by topological phase engineering has been realized experimentally to create the first two- and four-quantum vortices in dilute atomic Bose-Einstein condensates [A. E. Leanhardt et al., Phys. Rev. Lett. 89, 190403 (2002)]. We consider a similar system, but in addition to the Ioffe-Pritchard magnetic trap we employ an additional hexap

Soichiro Katayama, Hideo Kubo

The aim of this article is to present an elementary proof of a global existence result for nonlinear wave equations satifying the null condition in an exterior domain. The novelty of our proof is to avoid completely the scaling operator which would make the argument complicated in the mixed problem, by using a new weighted pointwise estimates of a tangential

Gustavo Dotti, Julio Oliva, Ricardo Troncoso

An exhaustive classification of certain class of static solutions for the five-dimensional Einstein-Gauss-Bonnet theory in vacuum is presented. The class of metrics under consideration is such that the spacelike section is a warped product of the real line with a nontrivial base manifold. It is shown that for generic values of the coupling constants the base

Robert Foot, Archil Kobakhidze, Kristian. L. McDonald, Raymond. R. Volkas

Scale invariance may be a classical symmetry which is broken radiatively. This provides a simple way to stabilize the scale of electroweak symmetry breaking against radiative corrections. The simplest phenomenologically successful model of this type involves the addition of one real scalar field to the standard model. In this minimal model the electroweak Hi

A. A. Arellano-Baeza, R. V. Garcia, M. Trejo-Soto

Over the last decades strong efforts have been made to apply new spaceborn technologies to the study and possible forecast of strong earthquakes. In this study we use ASTER/TERRA multispectral satellite images for detection and analysis of changes in the system of lineaments previous to a strong earthquake. A lineament is a straight or a somewhat curved feat

F. H. Jafarpour, P. Khaki

We introduce an exactly-solvable family of one-dimensional driven-diffusive systems defined on a discrete lattice. We find the quadratic algebra of this family which has an infinite-dimensional representation. We discuss the phase diagram of the system in a couple of special cases.

Yutaka Yoshikawa, Kazuyuki Nakayama, Yoshio Torii, Takahiro Kuga

We demonstrate superradiant conversion between a two-mode collective atomic state and a single-mode light field in an elongated cloud of Bose-condensed atoms. Two off-resonant write beams induce superradiant Raman scattering, producing two independent coherence gratings with a different wave vector in the cloud. By applying phase-matched read beams after a c

Francesco Buscemi

It is shown that, if the loss of entanglement along a quantum channel is sufficiently small, then approximate quantum error correction is possible, thereby generalizing what happens for coherent information. Explicit bounds are obtained for the entanglement of formation and the distillable entanglement, and their validity naturally extends to other bipartite

J. M. Pruneda, D. Sanchez-Portal, A. Arnau, J. I. Juaristi

Using time-dependent density-functional theory we calculate from first principles the rate of energy transfer from a moving proton or antiproton to the electrons of an insulating material, LiF. The behavior of the electronic stopping power versus projectile velocity displays an effective threshold velocity of ~0.2 a.u. for the proton, consistent with recent

H. King, J. M. Matthews, J. F. Rowe, C. Cameron

Using MOST (Microvariability and Oscillations of STars) satellite guide star photometry, we have discovered a metallic A star showing hybrid p- and g-mode pulsations. HD 114839 was observed nearly continuously for 10 days in March, 2005. We identify frequencies in three groups: the first centered near 2 cycles/day, in the gamma Dor pulsation range, and two o

Vladimir Mashkevich

The aim of these notes is to elucidate some aspects of quantum field theory in curved spacetime, especially those relating to the notion of particles. A selection of issues relevant to wave-particle duality is given. The case of a generic curved spacetime is outlined. A Hamiltonian formulation of quantum field theory in curved spacetime is elaborated for a p

Dimitris M. Christodoulou, Ioannis Contopoulos, Demosthenes Kazanas

We describe the results of numerical &#34;2.5--dimensional&#34; MHD simulations of an initially unmagnetized disk model orbiting a central point--mass and responding to the continual generation of poloidal magnetic field due to a secular source that emulates the Poynting--Robertson (PR) drag on electrons in the vicinity of a luminous stellar or compact accre

A. G. de Wijn, B. De Pontieu, R. J. Rutten

We study the dynamical interaction of the solar chromosphere with the transition region in mossy and non-mossy active-region plage. We carefully align image sequences taken with the Transition Region And Coronal Explorer (TRACE) in the ultraviolet passbands around 1550, 1600, and 1700 A and the extreme ultraviolet passbands at 171 and 195 A. We compute Fouri

A. G. de Wijn, B. De Pontieu

Aim: To study the interaction of the solar chromosphere with the transition region, in particular active-region jets in the transition region and their relation to chromospheric fibrils. Methods: We carefully align image sequences taken simultaneously in C IV with the Transition Region and Coronal Explorer and in H-alpha with the Swedish 1-m Solar Telescope.

Anne Broadbent, Alain Tapp

We present six multiparty protocols with information-theoretic security that tolerate an arbitrary number of corrupt participants. All protocols assume pairwise authentic private channels and a broadcast channel (in a single case, we require a simultaneous broadcast channel). We give protocols for veto, vote, anonymous bit transmission, collision detection,

A. G. de Wijn, R. J. Rutten, E. M. W. P. Haverkamp, P. Sütterlin

We use G-band and Ca II H image sequences from the Dutch Open Telescope (DOT) to study magnetic elements that appear as bright points in internetwork parts of the quiet solar photosphere and chromosphere. We find that many of these bright points appear recurrently with varying intensity and horizontal motion within longer-lived magnetic patches. We develop a

Ilya Nemenman, G. Sean Escola, William S. Hlavacek, Pat J. Unkefer

We investigate the ability of algorithms developed for reverse engineering of transcriptional regulatory networks to reconstruct metabolic networks from high-throughput metabolite profiling data. For this, we generate synthetic metabolic profiles for benchmarking purposes based on a well-established model for red blood cell metabolism. A variety of data sets

L. Binette, S. Haro-Corzo, Y. Krongold, A. C. Andersen

A prominent continuum steepening is observed in quasar energy distributions near 1100A. We review possible interpretations for the physical origin of this so-called far-UV break.

Joanne Mason, Fausto Cattaneo, Stanislav Boldyrev

We report the results of an extensive set of direct numerical simulations of forced, incompressible, magnetohydrodynamic turbulence with a strong guide field. The aim is to resolve the controversy regarding the power law exponent (α, say) of the field perpendicular energy spectrum E(k_\perp) \propto k_\perp ^ α. The two main theoretical predictions, α=-3/2 a

V. G. Gueorguiev, P. D. Kunz, J. E. Escher, F. S. Dietrich

We study the spin-parity distribution P(J$^π$,E) of $^{156}$Gd excited states above the neutron separation energy that are expected to be populated via the neutron pickup reaction $^{157}$Gd($^{3}$He,$^{4}$He)$^{156}$Gd. In general, modeling of the spin-parity distribution is important for the applicability of the surrogate reaction technique as a method of

J. M. Deutsch

In a variety of situations, isolated polymer molecules are found in a vacuum and here we examine their properties. Angular momentum conservation is shown to significantly alter the average size of a chain and its conservation is only broken slowly by thermal radiation. The time autocorrelation for monomer position oscillates with a characteristic time propor

N. Shah, C. J. Bolech

We have made a detailed proposal for a two-channel quantum dot setup. The energy scales in the problem are such that we are able to make connection with the two-channel Anderson model, which, in spite of being well-known in the context of heavy-Fermion systems remained theoretically elusive until recently and lacked a mesoscopic realization. Verification of

W. E. Harris, G. L. H. Harris, A. C. Layden, P. B. Stetson

We have used the ACS camera on HST to obtain (V,I) photometry for 57,000 red-giant stars in the halo of the Leo elliptical NGC 3377. We use this sample of stars to derive the metallicity distribution function (MDF) for its halo field stars, and comment on its chemical evolution history compared with both larger and smaller E galaxies. Our ACS/WFC field spans

Razvan Tudor Radulescu

As I compress on the canvas of a few pages here major results of my research on the retinoblastoma tumor suppressor protein (RB) spreading over the past 15 years, an exciting picture emerges on this unique host molecule which surpasses in its complexity even that of the most capable viral proteins known to date. Accordingly, RB has the potential to bind not

W. E. Harris, G. L. H. Harris, A. C. Layden, E. H. Wehner

We have used the ACS camera on HST to obtain (V,I) photometry for 5300 red-giant stars in the halo of the dominant Leo-group member NGC 3379, a galaxy usually regarded as a classic normal giant elliptical. We use this sample of stars to derive the metallicity distribution function (MDF) for its outer-halo field stars 33 kpc from the galaxy center. The MDF is

Gavin E. Crooks

In this note, we will discuss how to compactly express and prove the Jarzynski identity for an open quantum system with dissipative dynamics. We will avoid explicitly measuring the work directly, which is tantamount to continuously monitoring the system, and instead measure the heat flow from the environment. We represent the measurement of heat flow with He

Razvan Tudor Radulescu, Kai Kehe

Fifteen years ago, a structural analysis of the hormone insulin and the retinoblastoma tumor suppressor protein (RB) revealed that they may physically interact with one another. Subsequently, an RB peptide corresponding to the proposed RB binding site for insulin was found to recognize full-length insulin in vitro. As part of efforts aimed at developing this

A. G. de Wijn, R. J. Rutten, T. D. Tarbell

We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from the Transition Region and Coronal Explorer (TRACE) mission which were taken with strict cadence regularity. The latter

J. E. Medvedeva, E. N. Teasley, M. D. Hoffman

First-principles electronic band structure investigations of five compounds of the CaO-Al2O3 family, 3CaO.Al2O3, 12CaO.7Al2O3, CaO.Al2O3, CaO.2Al2O3 and CaO.6Al2O3, as well as CaO and alpha-, theta- and kappa-Al2O3 are performed. We find that the conduction band in the complex oxides is formed from the oxygen antibonding p-states and, although the band gap i

Ulrich Husemann

The large data samples of thousands of top events collected at the Tevatron experiments CDF and D0 allow for a variety of measurements to analyze the properties of the top quark. Guided by the question &#34;Is the top quark observed at the Tevatron really the top quark of the standard model,&#39;&#39; we present Tevatron analyses studying the top production

N. Grau

The first Pb+Pb collisions at the Large Hadron Collider (LHC) at sqrts_NN = 5.52 TeV are imminent. Heavy ion collisions at the LHC provide an extended energy lever arm to the existing measurements made at RHIC and SPS, especially in hard (large-Q^2) processes. In this contribution an overview of the ATLAS detector is given and the current physics focus of He

G. A. Alekseev, V. A. Belinski

An asymptotically flat static solution of Einstein-Maxwell equations which describes the field of two non-extreme Reissner - Nordström sources in equilibrium is presented. It is expressed in terms of physical parameters of the sources (their masses, charges and separating distance). Very simple analytical forms were found for the solution as well as for the

Keisuke Izumi, Kazuya Koyama, Oriol Pujolas, Takahiro Tanaka

We revisit the issue of the stability in the Dvali-Gabadadze-Porrati model, by considering the nucleation of bubbles of the conventional branch within the self-accelerating branch. We construct an instanton describing this process in the thin wall approximation. On one side of the bubble wall, the bulk consists of the exterior of the brane while on the other

Anna Maria Cherubini, Giorgio Metafune, Francesco Paparella

We study a simple model of a bouncing ball that takes explicitely into account the elastic deformability of the body and the energy dissipation due to internal friction. We show that this model is not subject to the problem of inelastic collapse, that is, it does not allow an infinite number of impacts in a finite time. We compute asymptotic expressions for

Katherine Vieira, Dana I. Casetti-Dinescu, Rene A. Mendez, R. Michael Rich

A proper motion study of a field of 20&#39; x 20&#39; inside Plaut&#39;s low extinction window (l,b)=(0 deg,-8 deg), has been completed. Relative proper motions and photographic BV photometry have been derived for ~21,000 stars reaching to V~20.5 mag, based on the astrometric reduction of 43 photographic plates, spanning over 21 years of epoch difference. Pr

Dragomir Z. Djokovic

We construct two difference families on each of the cyclic groups of order 109, 145 and 247, and use them to construct skew-Hadamard matrices of orders 436, 580 and 988. Such difference families and matrices are constructed here for the first time. The matrices are constructed by using the Goethals-Seidel array.

Bhavtosh Bansal, M. Hayne, M. Geller, D. Bimberg

Photoluminescence spectra measured on a type-II GaSb/GaAs quantum dot ensemble at high excitation power indicate a Mott transition from the low density state comprising of spatially-indirect excitons to a high density electron-plasma state. Under the influence of a very high magnetic field, the electron-plasma that is formed at high excitation powers is `fro

Antonio Cordoba, Diego Cordoba, Marco A. Fontelos

We study a 1D transport equation with nonlocal velocity and show the formation of singularities in finite time for a generic family of initial data. By adding a diffusion term the finite time singularity is prevented and the solutions exist globally in time.

Andrzej Madrecki

An elementary analytic proof of the famous Riemann hypothesis is given. The main &#34;accent&#34; of the proof is a both using of the 2-dimensional double real and complex Laplace integral representations of the Green function $\mid z \mid^{-2}$.

T. P. Idiart, W. J. Maciel, R. D. D. Costa

We investigate the chemical evolution of the Small Magellanic Cloud (SMC) based on abundance data of planetary nebulae (PNe). The main goal is to investigate the time evolution of the oxygen abundance in this galaxy by deriving an age-metallicity relation. Such a relation is of fundamental importance as an observational constraint of chemical evolution model

Elias P. Gyftopoulos

The information-theoretic arguments presented in a recent publication on &#34;Quantum discord and Maxwell&#39;s demons&#34; are discussed, and found not to address the problem specified by Maxwell. Two interrelated and definitive exorcisms of the demon, one purely thermodynamic, and the other quantum-thermodynamic are briefly discussed. For each of the two e

Adam J. Burgasser

SDSS J080531.84+481233.0 is a peculiar L-type dwarf that exhibits unusually blue near-infrared and mid-infrared colors and divergent optical (L4) and near-infrared (L9.5) spectral classifications. These peculiar spectral traits have been variously attributed to condensate cloud effects or subsolar metallicity. Here I present an improved near-infrared spectru

Lado Samushia, Gang Chen, Bharat Ratra

Galaxy cluster gas mass fraction versus redshift data and Hubble parameter versus redshift data are used to jointly constrain dark energy models. These constraints favor the Einstein cosmological constant limit of dark energy but do not strongly rule out slowly-evolving dark energy.

Robert A. Wittenmyer, Michael Endl, William D. Cochran, Harold F. Levison

Long time coverage and high radial velocity precision have allowed for the discovery of additional objects in known planetary systems. Many of the extrasolar planets detected have highly eccentric orbits, which raises the question of how likely those systems are to host additional planets. We investigate six systems which contain a very eccentric (e>0.6) pla

Joseph D. Masters

We show that every finitely-generated free subgroup of a right-angled, co-compact Kleinian reflection group is contained in a surface subgroup.

A. S. Umar, V. E. Oberacker

We present a new approach for calculating the nuclear equation of state and compressibility for finite nuclei using the density-constrained Hartree-Fock method.

E. Dalla Bonta&#39;, L. Ferrarese, E. M. Corsini, J. Miralda-Escude

Two brightest cluster galaxies (BCGs), namely Abell 1836-BCG and Abell 3565-BCG, were observed with the Advanced Camera for Surveys (ACS) and the Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space Telescope. By modeling the available photometric and kinematic data, it resulted that the mass of Abell 1836-BCG and Abell 3565-BCG are M_bh=4.8

Jorge Caravantes

In this note we study Fano threefolds with noncyclic torsion in the divisor class group. Since they can all be obtained as quotients of Fano threefolds, we get also all examples that can be obtained as quotients of low codimension Fanos in the weighted projective space.

Stephen G. Naculich, Benjamin H. Ripman

We analyze the level-rank duality of untwisted and epsilon-twisted D-branes of the so(N)_K WZW model. Untwisted D-branes of so(N)_K are characterized by integrable tensor and spinor representations of so(N)_K. Level-rank duality maps untwisted so(N)_K D-branes corresponding to (equivalence classes of) tensor representations onto those of so(K)_N. The epsilon

Boaz Tsaban

Contents: 1. Editor&#39;s note; 2. Personal impressions from the SPM07 meeting; 3. Research announcements; 3.1. Coloring ordinals by reals; 3.2. Long Borel Hierarchies; 3.3. Rothberger&#39;s property in finite powers; 3.4. Special subsets of the reals and tree forcing notions; 3.5. All automorphisms of the Calkin algebra are inner; 3.6. Continuous selections

Edgar Delgado-Eckert

The aim of this paper is to unveil an unexpected relationship between the normal form of a polynomial with respect to a polynomial ideal and the more geometric concept of orthogonality. We present a new way to calculate the normal form of a polynomial with respect to a polynomial ideal I in the ring of multivariate polynomials over a field K, provided the fi

J. M. Taylor, T. Calarco

Atomic systems in regular lattices are intriguing systems for implementing ideas in quantum simulation and information processing. Focusing on laser cooled ions forming Wigner crystals in Penning traps, we find a robust and simple approach to engineering non-trivial 2-body interactions sufficient for universal quantum computation. We then consider extensions

S. Fratini, A. F. Morpurgo, S. Ciuchi

Recent experiments have demonstrated that the performances of organic FETs strongly depend on the dielectric properties of the gate insulator. In particular, it has been shown that the temperature dependence of the mobility evolves from a metallic-like to an insulating behavior upon increasing the dielectric constant of the gate material. This phenomenon can

Nikolaos Tombros, Csaba Jozsa, Mihaita Popinciuc, Harry T. Jonkman

The specific band structure of graphene, with its unique valley structure and Dirac neutrality point separating hole states from electron states has led to the observation of new electronic transport phenomena such as anomalously quantized Hall effects, absence of weak localization and the existence of a minimum conductivity. In addition to dissipative trans

T. Ruchon, C. P. Hauri, K. Varju, E. Gustafsson

We examine how the generation and propagation of high-order harmonics in a partly ionized gas medium affect their strength and synchronization. The temporal properties of the resulting attosecond pulses generated in long gas targets can be significantly influenced by macroscopic effects, in particular by the intensity in the medium and the degree of ionizati

A. Castillo-Morales, J. Jimenez-Vicente, E. Mediavilla, E. Battaner

We analyse new integral field spectroscopy of the inner region (central 2.5 kpc) of the spiral galaxy NGC 4321 to study the peculiar kinematics of this region. Fourier analysis of the velocity residuals obtained by subtracting an axisymmetric rotation model from the $\rm Hα$ velocity field, indicates that the distortions are {\em global} features generated b

Alessandro Capetti, David J. Axon, Marco Chiaberge, William B. Sparks

We obtained optical imaging polarimetry with the ACS/HRC aboard the HST of the 9 closest radio-galaxies in the 3C catalogue with an FR I morphology. The nuclear sources seen in direct HST images in these galaxies are found to be highly polarized with levels in the range ~2-11 % with a median value of 7 %. We discuss the different mechanisms that produce pola

Xuehan Cheng, Wu Jing

In this short note we prove that every Jordan derivation of triangular algebras is a derivation.

Jonathan J. Crofts

An algorithm for detecting unstable periodic orbits in chaotic systems [Phys. Rev. E, 60 (1999), pp. 6172-6175] which combines the set of stabilising transformations proposed by Schmelcher and Diakonos [Phys. Rev. Lett., 78 (1997), pp. 4733-4736] with a modified semi-implicit Euler iterative scheme and seeding with periodic orbits of neighbouring periods, ha

T. M. Bania, Dana S. Balser, Robert T. Rood, T. L. Wilson

The cosmic abundance of the 3-He isotope has important implications for many fields of astrophysics. We are using the 8.665 GHz hyperfine transition of 3-He+ to determine the 3-He/H abundance in Milky Way HII regions and planetary nebulae. This is one in a series of papers in which we discuss issues involved in deriving accurate 3-He/H abundance ratios from

Elias P. Gyftopoulos, Michael R. von Spakovsky

A process has been proposed to increase the efficiency of an ideal Otto cycle via a quantum heat engine that has no cooler reservoir. We show that such a process is not feasible.

N. Arcozzi, R. Rochberg, E. Sawyer

We give a simple proof of the characterization of the Carleson measures for the weighted analytic Besov spaces. Such characterization provides some information on the radial variation of an analytic Besov function.

Florent Brenguier, Nikolai M. Shapiro, Michel Campillo, Valerie Ferrazzini

During inter-eruption periods, magma pressurization yields subtle changes of the elastic properties of volcanic edifices. We use the reproducibility properties of the ambient seismic noise recorded on the Piton de la Fournaise volcano to measure relative seismic velocity variations of less than 0.1 % with a temporal resolution of one day. Our results show th

Petr Marek, Radim Filip

A basic feasible probabilistic purification of unknown noisy coherent states, outgoing from different state preparations with unknown mean number of thermal photons, is proposed. The scheme is based only on a linear-optical network with an avalanche photo-diode or heterodyne (homodyne) detection used to post-select a successful processing. The suggested prob

Vassili N. Kolokoltsov

Functional limit theorem for continuous-time random walks (CTRW) are found in general case of dependent waiting times and jump sizes that are also position dependent. The limiting anomalous diffusion is described in terms of fractional dynamics. Probabilistic interpretation of generalized fractional evolution is given in terms of the random time change (subo

Michele Bezzi, Robin Groenevelt

Measuring and modeling human behavior is a very complex task. In this paper we present our initial thoughts on modeling and automatic recognition of some human activities in an office. We argue that to successfully model human activities, we need to consider both individual behavior and group dynamics. To demonstrate these theoretical approaches, we introduc

Nicolas Sangouard, Christoph Simon, Jiri Minar, Hugo Zbinden

We present an efficient architecture for quantum repeaters based on single-photon sources in combination with quantum memories for photons. Errors inherent to previous repeater protocols using photon-pair sources are eliminated, leading to a significant gain in efficiency. We establish the requirements on the single-photon sources and on the photon detectors

Ralph Engel

The Pierre Auger Observatory allows the measurement of both longitudinal profiles and lateral particle distributions of high-energy showers. The former trace the overall shower development, mainly of the electromagnetic component close to the core where the latter reflect the particle densities in the tail of the shower far away from the core and are sensiti

Lucian A. Constantin, J. M. Pitarke

We propose a simple dynamic exchange-correlation kernel of the uniform electron gas. We model the reduction of the electron-electron interaction due to short-range exchange-correlation effects by introducing a frequency-dependent error-function effective interaction. By imposing the fulfillment of the compresibility and the third-frequency-moment sum rules,

Michael Joswig, Bernd Sturmfels, Josephine Yu

The notion of convexity in tropical geometry is closely related to notions of convexity in the theory of affine buildings. We explore this relationship from a combinatorial and computational perspective. Our results include a convex hull algorithm for the Bruhat--Tits building of SL$_d(K)$ and techniques for computing with apartments and membranes. While the

Philip Hardee, Yosuke Mizuno, Ken-Ichi Nishikawa

A new general relativistic magnetohydrodynamics (GRMHD) code ``RAISHIN&#39;&#39; used to simulate jet generation by rotating and non-rotating black holes with a geometrically thin Keplarian accretion disk finds that the jet develops a spine-sheath structure in the rotating black hole case. Spine-sheath structure and strong magnetic fields significantly modif

Matias Graña, Jorge A. Guccione, Juan J. Guccione

We show how to define the tensor product of two braided Hopf algebras.

Ali Mohammad-Djafari

In a non supervised Bayesian estimation approach for inverse problems in imaging systems, one tries to estimate jointly the unknown image pixels $\fb$ and the hyperparameters $\thetab$. This is, in general, done through the joint posterior law $p(\fb,\thetab|\gb)$. The expression of this joint law is often very complex and its exploration through sampling an

E. Quemerais, R. Lallement, D. Koutroumpa, P. Lamy

We present a method to derive outflow velocities in the solar corona using different data sets including solar wind mass flux coming from the SWAN/SOHO instrument, electron density values from LASCO-C2 and interplanetary solar wind velocities derived from ground-based Interplanetary Scintillation Observations (IPS). In a first step, we combine the LASCO elec

Edouard J. Bernard, Antonio Aparicio, Carme Gallart, Carmen P. Padilla-Torres

We present resolved-star VI photometry of the Local Group dwarf irregular galaxy IC1613 reaching I~23.5, obtained with the wide-field camera at the 2.5m Isaac Newton Telescope. A fit to the stellar density distribution shows an exponential profile of scale length 2.9&#39; +/- 0.1 and gives a central surface brightness mu_V,0 = 22.7 +/- 0.6. The significant n

G. Q. Liang, W. D. Mao, H. Zou, B. C. Chen

We theoretically demonstrate the formation of different kinds of two-dimensional split-ring arrays in both triangular and square lattices by one-step holographic interference. The slit width of the split-ring can be adjusted by proper polarization configurations. The dimension of the rings can be adjusted easily by using different wavelengths for interferenc

T. D. Morton, P. Slane, K. J. Borkowski, S. P. Reynolds

We present Spitzer Space Telescope and Chandra X-ray Observatory observations of the composite Galactic supernova remnant Kes 75 (G29.7-0.3). We use the detected flux at 24 microns and hot gas parameters from fitting spectra from new, deep X-ray observations to constrain models of dust emission, obtaining a dust-to-gas mass ratio M_dust/M_gas ~0.001. We find

Paul Vojta

In 1962-63, M. Nagata showed that an abstract variety could be embedded into a complete variety. Later, P. Deligne translated Nagata&#39;s proof into the language of schemes, but did not publish his notes. This paper, which is to appear as an appendix in a forthcoming book, gives an elaboration of Deligne&#39;s notes. It also contains some complementary resu

Hiroshi Fujisaki, Kiyoshi Yagi, Kimihiko Hirao, John E. Straub

Vibrational energy transfer of the amide I mode of N-methylacetamide (NMA) is studied theoretically using the vibrational configuration interaction method. A quartic force field of NMA is constructed at the B3LYP/6-31G+(d) level of theory and its accuarcy is checked by comparing the resulting anharmonic frequencies with available theoretical and experimental

Cristian Pisano

Perturbative NLO and NNLO QCD evolutions of parton distributions are studied, in particular in the (very) small-x region, where they are in very good agreement with all recent precision measurements of F_2^p(x,Q^2). These predictions turn out to be also rather insensitive to the specific choice of the factorization scheme (MS or DIS). A characteristic featur

Victor Katsnelson, Bernd Kirstein

A theory of matrix-valued functions from the matricial Smirnov class ${\goth N}_n^+({\Bbb D})$ is systematically developed. In particular, the maximum principle of V.I.Smirnov, inner-outer factorization, the Smirnov-Beurling characterization of outer functions and an analogue of Frostman&#39;s theorem are presented for matrix-valued functions from the Smirno

B. Vicente, C. Abad, F. Garzon

We present an original method of digitizing and astrometrically reducing &#34;Carte du Ciel&#34; plate material using an inexpensive flatbed scanner, to demonstrate that for this material there is an alternative to more specialized measuring machines that are very few in number and thus not readily available. The sample of plates chosen to develop this metho

L. Fatibene, M. Francaviglia, C. Rovelli

We shall here discuss a new spacetime gauge-covariant Lagrangian formulation of General Relativity by means of the Barbero-Immirzi SU(2)-connection on spacetime. To the best of our knowledge the Lagrangian based on SU(2) spacetime fields seems to appear here for the first time.

E. Yazgan, J. Damgov, N. Akchurin, V. Genchev

We present the potential for discovering the Standard Model Higgs boson produced by the vector-boson fusion mechanism. We considered the decay of Higgs bosons into the W+W- final state, with both W-bosons subsequently decaying leptonically. The main background is ttbar with one or more jets produced. This study is based on a full simulation of the CMS detect