July 2009 arXiv papers — page 46

Sariel Har-Peled

We present a linear programming based algorithm for computing a spanning tree $T$ of a set $P$ of $n$ points in $\Re^d$, such that its crossing number is $O(\min(t \log n, n^{1-1/d}))$, where $t$ the minimum crossing number of any spanning tree of $P$. This is the first guaranteed approximation algorithm for this problem. We provide a similar approximation a

Julio Oliva, David Tempo, Ricardo Troncoso

A static spherically symmetric wormhole solution for conformal gravity in vacuum is found. The solution possesses a single integration constant which determines the size of the neck connecting two static homogeneous universes of constant spatial curvature. Time runs at different rates on each side of the neck, and depending on the value of the parameter, the

Hongwei Xiong, Shujuan Liu

We study the parity effect of the particle number in the interference fringes of a Bose-Einstein condensate released from a double-well potential. For a coherently splitting condensate in the double-well potential, with a decoupled two-mode Bose-Hubbard model, there is well-known phase diffusion because of interatomic interactions. After a specific holding t

A. A. Taskin, Yoichi Ando

We have studied transport and magnetic properties of Bi_{1-x}Sb_x, which is believed to be a topological insulator - a new state of matter where an insulating bulk supports an intrinsically metallic surface. In nominally insulating Bi_{0.91}Sb_{0.09} crystals, we observed strong quantum oscillations of the magnetization and the resistivity originating from a

Stefan Wolf

Let Q be a quiver. M. Reineke and A. Hubery investigated the connection between the composition monoid, as introduced by M. Reineke, and the generic composition algebra, as introduced by C. M. Ringel, specialised at q=0. In this thesis we continue their work. We show that if Q is a Dynkin quiver or an oriented cycle, then the composition algebra at q=0 is is

Joshua D. Simon, Avishay Gal-Yam, Orly Gnat, Robert M. Quimby

Recent observations have revealed that some Type Ia supernovae exhibit narrow, time-variable Na I D absorption features. The origin of the absorbing material is controversial, but it may suggest the presence of circumstellar gas in the progenitor system prior to the explosion, with significant implications for the nature of the supernova progenitors. We pres

C. J. Cotter

Diffeomorphic matching (only one of several names for this technique) is a technique for non-rigid registration of curves and surfaces in which the curve or surface is embedded in the flow of a time-series of vector fields. One seeks the flow between two topologically-equivalent curves or surfaces which minimises some metric defined on the vector fields, \em

Zdzisław Naniewicz, Piotr Puchała

A double-well energy expressed as a minimum of two quadratic functions, called phase energies, is studied with taking into account the minimization of the corresponding integral functional. Such integral, as being not sequentially weakly lower semicontinuous, does not admit classical minimizers. To derive the relaxation formula for the infimum, the minimizin

Gerald E. Marsh

Emergent behavior that appears at a given level of organization may be characterized as arising from an organizationally lower level in such a way that it transcends a mere increase in the behavioral degree of complexity. It is therefore to be distinguished from systems exhibiting chaotic behavior, for example, which are deterministic but unpredictable becau

Constantino A. Utreras Díaz, David Laroze

We consider a quantum $LC$ circuit under a constant magnetic flux $f$, and derive a discretized form of the Schrödinger equation, which is equivalent to introducing a {\em potential} $V(ϕ,f)$ in the pseudo-flux $ϕ$-representation, which is different from that found previously by Li and Chen \cite{LI-CHEN}. Firts, we discuss the physical assumptions leading t

Antonio Galves, Nancy L. Garcia, Clementine Prieur

We explicitly construct a coupling attaining Ornstein's $\bar{d}$-distance between ordered pairs of binary chains of infinite order. Our main tool is a representation of the transition probabilities of the coupled bivariate chain of infinite order as a countable mixture of Markov transition probabilities of increasing order. Under suitable conditions on

E. G. Cavalcanti, S. J. Jones, H. M. Wiseman, M. D. Reid

We formally link the concept of steering (a concept created by Schrodinger but only recently formalised by Wiseman, Jones and Doherty [Phys. Rev. Lett. 98, 140402 (2007)] and the criteria for demonstrations of Einstein-Podolsky-Rosen (EPR) paradox introduced by Reid [Phys. Rev. A, 40, 913 (1989)]. We develop a general theory of experimental EPR-steering crit

Jonathan Debove, Benjamin Fuks, Michael Klasen

We present a first precision analysis of the transverse-momentum spectrum of gaugino pairs produced at the Tevatron and the LHC with center-of-mass energies of 1.96 and 10 or 14 TeV, respectively. Our calculation is based on a universal resummation formalism at next-to-leading logarithmic accuracy, which is consistently matched to the perturbative prediction

Richard J. Mathar

The displacement of star images by atmospheric refraction observed by an Earth-bound telescope is dominated by a familiar term proportional to the product of the tangent of the zenith angle by the refractivity at the ground. The manuscript focuses on the torsion of the ray path through the atmosphere in a model of atmospheric layers above the ellipsoidal Ear

Mark Girolami, Ben Calderhead, Siu A. Chin

The paper proposes a Riemannian Manifold Hamiltonian Monte Carlo sampler to resolve the shortcomings of existing Monte Carlo algorithms when sampling from target densities that may be high dimensional and exhibit strong correlations. The method provides a fully automated adaptation mechanism that circumvents the costly pilot runs required to tune proposal de

J. E. Austermann, J. S. Dunlop, T. A. Perera, K. S. Scott

We present the first results from the largest deep extragalactic millimetre-wavelength survey undertaken to date. These results are derived from maps covering over 0.7 deg^2, made at 1.1mm, using the AzTEC continuum camera mounted on the James Clerk Maxwell Telescope. The maps were made in the two fields originally targeted at 0.85mm with SCUBA in the SHADES

Ole Host, Steen H. Hansen

The distribution of mass in the halos of galaxies and galaxy clusters has been probed observationally, theoretically, and in numerical simulations. Yet there is still confusion about which of several suggested parameterized models is the better representation, and whether these models are universal. We use the temperature and density profiles of the intraclu

Scott Pratt

At the onset of the RHIC era femtoscopic source sizes inferred from two-particle correlations at RHIC defied description with hydrodynamic models. This failure, which became known as the HBT puzzle, now appears to be solved. The source of the discrepancy appears to be a conspiracy of several factors, each of which contributed to making the evolution of RHIC

Rom Varshamov, Armen Bagdasaryan

In this paper we present a new mathematical conception based on a new method for ordering the integers. The method relies on the assumption that negative numbers are beyond infinity, which goes back to Wallis and Euler. We also present a new axiom system, the model of which is arithmetics. We define regular method for summation of infinite series which allow

I. V. Danilkin, Yu. A. Simonov

The mechanism of channel coupling via decay products is used to study energy shifts, level mixing as well as the possibility of new near-threshold resonances in $c\bar c, b\bar b$ systems. The Weinberg eigenvalue method is formulated in the multichannel problems, which allows to describe coupled-channel resonances and wave functions in a unitary way, and to

Sophia K. Domokos, Jeffrey A. Harvey, Nelia Mann

We consider the differential and total cross sections for proton-proton and proton-antiproton scattering in the Regge regime from the point of view of string dual models of QCD. We argue that the form factor which appears in the differential cross section is related to the matrix element of the stress tensor between proton states and give a procedure for com

Deokkeun An, Jennifer A. Johnson, Timothy C. Beers, Marc H. Pinsonneault

We determine photometric metal abundance estimates for individual main-sequence stars in the Virgo Overdensity (VOD), which covers almost 1000 deg^2 on the sky, based on a calibration of the metallicity sensitivity of stellar isochrones in the gri filter passbands using field stars with well-determined spectroscopic metal abundances. Despite the low precisio

Philip Goyal, Kevin H. Knuth, John Skilling

Complex numbers are an intrinsic part of the mathematical formalism of quantum theory, and are perhaps its most mysterious feature. In this paper, we show that the complex nature of the quantum formalism can be derived directly from the assumption that a pair of real numbers is associated with each sequence of measurement outcomes, with the probability of th

Jacob S. Levy, Alexander Gondarenko, Mark A. Foster, Amy C. Turner-Foster

Silicon photonics enables on-chip ultra-high bandwidth optical communications networks which is critical for the future of microelectronics1,2. By encoding information on-chip using multiple wavelength channels through the process of wavelength division multiplexing (WDM), communication bandwidths in excess of 1 Tbit s-1 are possible3. Already several optica

J. M. Marcaide, I. Marti-Vidal, M. A. Perez-Torres, A. Alberdi

We report on 1.6 GHz Very-Long-Baseline-Interferometry (VLBI) observations of supernova SN 1979C made on 18 November 2002. We derive a model-dependent supernova size. We also present a reanalysis of VLBI observations made by us on June 1999 and by other authors on February 2005. We conclude that, contrary to our earlier claim of strong deceleration in the ex

Matt Clay, Alexandra Pettet

We show that for k at least 3, given any matrix in GL(k,Z), there is a hyperbolic fully irreducible automorphism of the free group of rank k whose induced action on Z^k is the given matrix.

Aaron Sterling

In 2004, Klavins et al. introduced the use of graph grammars to describe -- and to program -- systems of self-assembly. We show that these graph grammars can be embedded in a graph rewriting characterization of distributed systems that was proposed by Degano and Montanari over twenty years ago. We apply this embedding to generalize Soloveichik and Winfree&#3

Eric Harper, Nikolai Saveliev

We define an integer valued invariant for two-component links in S^3 by counting projective SU(2) representations of the link group having non-trivial second Stiefel-Whitney class. We show that our invariant is, up to sign, the linking number of the link. Our construction generalizes that of X.-S. Lin who defined a similar invariant for knots in S^3; his inv

Adrian L. Melott, Brian C. Thomas, Gisela Dreschhoff, Carey K. Johnson

We find agreement between models of atmospheric chemistry changes from ionization for the 1908 Tunguska airburst event and nitrate enhancement in GISP2H and GISP2 ice cores, plus an unexplained ammonium spike. We then consider a candidate cometary impact at the Younger Dryas onset (YD). The large estimated NO_x production and O_3 depletion are beyond accurat

Makiko Nagashima, Ken Kiers, Alejandro Szynkman, David London

CP violation in supersymmetry can give rise to rate asymmetries in the decays of supersymmetric particles. In this work we compute the rate asymmetries for the three-body chargino decays \tilde\chi^\pm_2 \to \tilde\chi^\pm_1 HH, \tilde\chi^\pm_2 \to \tilde\chi^\pm_1 ZZ, \tilde\chi^\pm_2 \to \tilde\chi^\pm_1 W^+ W^- and \tilde\chi^\pm_2 \to tilde\chi^\pm_1 ZH

George Kamal Atia, Venkatesh Saligrama

The fundamental task of group testing is to recover a small distinguished subset of items from a large population while efficiently reducing the total number of tests (measurements). The key contribution of this paper is in adopting a new information-theoretic perspective on group testing problems. We formulate the group testing problem as a channel coding/d

G. Ramalho, K. Tsushima, Franz Gross

We compute the Omega- electromagnetic form factors and the decuplet baryon magnetic moments using a quark model application of the Covariant Spectator Theory. Our predictions for the Omega- electromagnetic form factors can be tested in the future by lattice QCD simulations at the physical strange quark mass.

Ignat V. Fialkovsky, Vladimir N. Markov, Yuriy M. Pis'mak

We study the field theoretical model of a scalar field in presence of spacial inhomogeneities in form of one and two finite width mirrors (material slabs). The interaction of the scalar field with the defect is described with position-dependent mass term. For the single layer system we develop a rigorous calculation method and derive explicitly the propagato

Xijia Miao

The multiple-quantum NMR spectroscopy has an extensive application in determination of the bio-macro-molecular structures and in the investigation of the properties of a variety of physical materials. In quantum computation the multiple-quantum transition processes have been used to construct the quantum circuits, quantum algorithms, and quantum simulations.

C. Ledoux, P. M. Vreeswijk, A. Smette, A. J. Fox

We aim to understand the nature of the absorbing neutral gas in the galaxies hosting high-redshift long-duration GRBs and to determine their physical conditions. We report the detection of a significant number of previously unidentified allowed transition lines of Fe+, involving the fine structure of the ground term and that of other excited levels, from the

Christoph Spengler, Marcus Huber, Beatrix C. Hiesmayr

We compare entanglement with quantum nonlocality employing a geometric structure of the state space of bipartite qudits. Central object is a regular simplex spanned by generalized Bell states. The Collins-Gisin-Linden-Massar-Popescu-Bell inequality is used to reveal states of this set that cannot be described by local-realistic theories. Optimal measurement

Filippo Radicchi, Santo Fortunato, Benjamin Markines, Alessandro Vespignani

Recently, the abundance of digital data enabled the implementation of graph based ranking algorithms that provide system level analysis for ranking publications and authors. Here we take advantage of the entire Physical Review publication archive (1893-2006) to construct authors' networks where weighted edges, as measured from opportunely normalized cita

Mikhail Belkin, Kaushik Sinha

In this paper we present a method for learning the parameters of a mixture of $k$ identical spherical Gaussians in $n$-dimensional space with an arbitrarily small separation between the components. Our algorithm is polynomial in all parameters other than $k$. The algorithm is based on an appropriate grid search over the space of parameters. The theoretical a

E. Cobanera, G. Ortiz, Z. Nussinov

We show how classical and quantum dualities, as well as duality relations that appear only in a sector of certain theories ("emergent dualities"), can be unveiled, and systematically established. Our method relies on the use of morphisms of the "bond algebra" of a quantum Hamiltonian. Dualities are characterized as unitary mappings implementi

Seung-Moon Hong, Eric C. Rowell

We develop a symbolic computational approach to classifying low-rank modular categories. We use this technique to classify pseudo-unitary modular categories of rank at most 5 that are non-self-dual, i.e. those for which some object is not isomorphic to its dual object.

Federico Piazza

We have recently proposed an "Ultra-Strong" version of the Equivalence Principle (EP) that is not satisfied by standard semiclassical gravity. In the theory that we are conjecturing, the vacuum expectation value of the (bare) energy momentum tensor is exactly the same as in flat space: quartically divergent with the cut-off and with no spacetime depe

The MAGIC Collaboration, H. Anderhub, L. A. Antonelli, P. Antoranz

Index entry listing the contributed papers of the MAGIC collaboration to the 31th International Cosmic Ray Conference (ICRC 2009), July 7-15 2009, Łódź, Poland. The individual papers are sorted by subject: Overview and Highlight Papers; MAGIC-II Status and Components; Software and Analysis Techniques; Technical Developments; Scientific Results. This HTML doc

William M. McGovern

We characterize the Sp_{2n} orbits in the flag variety for SL_{2n} with rationally smooth closure via a pattern avoidance criterion, also showing that the singular and rationally singular loci of such orbit closures coincide.

The D0 Collaboration, V. Abazov

A search for pair production of first-generation leptoquarks LQ is performed with data collected by the D0 experiment in p pbar collisions at sqrt(s)=1.96 TeV at the Fermilab Tevatron Collider. In a sample of data corresponding to ~1 fb-1, the search has been performed on the final states with two electrons and two jets or one electron, two jets and missing

D. S. Kosov

Based on the formalism of thermo field dynamics we propose a concept of nonequilibrium Fock space and nonequilibrium quasiparticles for quantum many-body system in nonequilibrium steady state. We develop a general theory as well as demonstrate the utility of the approach on the example of electron transport through the interacting region. The proposed approa

Floriana Giannuzzi, Massimo Mannarelli

We investigate the properties of charmonia in a thermal medium, showing that with increasing temperature the decay widths of these mesons behave in a non-trivial way. Our analysis is based on a potential model with interaction potential extracted from thermal lattice QCD calculations of the free-energy of a static quark-antiquark pair. We find that in the cr

Liping Fu, Martin Kilbinger

The decomposition of the cosmic shear field into E- and B-mode is an important diagnostic in weak gravitational lensing. However, commonly used techniques to perform this separation suffer from mode-mixing on very small or very large scales. We introduce a new E-/B-mode decomposition of the cosmic shear two-point correlation on a finite interval. This new st

G. Giacinti, X. Derkx, D. V. Semikoz

In this paper, we suggest a new way to identify single bright sources of Ultra High Energy Cosmic Rays (UHECR) on the sky, on top of background. We look for doublets of events at the highest energies, E > 6 x 10^19 eV, and identify low energy tails, which are deflected by the Galactic Magnetic Field (GMF). For the sources which are detected, we can recover t

Claudio Dappiaggi, Valter Moretti, Nicola Pinamonti

The discovery of the radiation properties of black holes prompted the search for a natural candidate quantum ground state for a massless scalar field theory on Schwarzschild spacetime, here considered in the Eddington-Finkelstein representation. Among the several available proposals in the literature, an important physical role is played by the so-called Unr

Peter Arnold

I report on some theoretical progress concerning the calculation of gluon bremsstrahlung for very high energy particles crossing a weakly-coupled quark-gluon plasma. (i) I advertise that two of the several formalisms used to study this problem, the BDMPS-Zakharov formalism and the AMY formalism (the latter used only for infinite, uniform media), can be made

P. Colin, D. Borla Tridon, D. Britzger, E. Lorenz

Recent measurements of the cosmic-ray electron (e-) and positron (e+) fluxes show apparent excesses compared to the spectra expected by standard cosmic-ray (CR) propagation models in our galaxy. These excesses may be related to particle acceleration in local astrophysical objects, or to dark matter annihilation/decay. The e+/e- ratio (measured up to ~100 GeV

Michael A. Ivanov

The average time delay of photons due to multiple interactions with gravitons of the background is computed in a frame of the model of low-energy quantum gravity by the author. The two variants of evaluation of the lifetime of a virtual photon are considered: 1$)$ on a basis of the uncertainties relation (it is a common place in physics of particles) and 2$)

Chao-Yang Pang, Wei Hu, Xia Li, Be-Qiong Hu

Ant Colony Optimization (ACO) has time complexity O(t*m*N*N), and its typical application is to solve Traveling Salesman Problem (TSP), where t, m, and N denotes the iteration number, number of ants, number of cities respectively. Cutting down running time is one of study focuses, and one way is to decrease parameter t and N, especially N. For this focus, th

Alice Sinatra, Yvan Castin, Emilia Witkowska

Temporal coherence is a fundamental property of macroscopic quantum systems, such as lasers in optics and Bose-Einstein condensates in atomic gases and it is a crucial issue for interferometry applications with light or matter waves. Whereas the laser is an "open" quantum system, ultracold atomic gases are weakly coupled to the environment and may be

C. G. Madonna

We give many examples in which there exist infinitely many divisorial conditions on the moduli space of polarized K3 surfaces $(S,H)$ of degree $H^2=2g-2$, $g \geq 3$, and Picard number $rk N(S)=ρ(S)=2$ such that for a general K3 surface $S$ satisfying these conditions the moduli space of sheaves $M_S(r,H,s)$ is birationally equivalent to the Hilbert scheme

R. Gaudoin, J. M. Pitarke

In a recent Letter we introduced Hellmann-Feynman operator sampling in diffusion Monte Carlo calculations. Here we derive, by evaluating the second derivative of the total energy, an efficient method for the calculation of the static density-response function of a many-electron system. Our analysis of the effect of the nodes suggests that correlation is desc

Jing-Rong Wang, Guo-Zhu Liu

We study the damping rate of massless Dirac fermions due to the U(1) gauge field in (2+1)-dimensional quantum electrodynamics. In the absence of a Maxwell term for the gauge field, the fermion damping rate $\mathrm{Im}Σ(ω,T)$ is found to diverge in both perturbative and self-consistent results. In the presence of a Maxwell term, there is still divergence in

M. Battaglieri, R. De Vita, A. P. Szczepaniak

The exclusive reaction $\gamma p \to p \pi^+ \pi^-$ was studied in the photon energy range 3.0 - 3.8 GeV and momentum transfer range $0.4<-t<1.0$ GeV$^2$. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. In this kinematic range the integrated luminosity was about 20 pb$^{-1}$. The reaction was isolated by dete

Vladislav B. Tadic

The asymptotic behavior of stochastic gradient algorithms is studied. Relying on results from differential geometry (Lojasiewicz gradient inequality), the single limit-point convergence of the algorithm iterates is demonstrated and relatively tight bounds on the convergence rate are derived. In sharp contrast to the existing asymptotic results, the new resul

R. Caimmi

Macrogases are defined as two-component, large-scale celestial objects where the subsystems interact only via gravitation. The macrogas equation of state is formulated and compared to the van der Waals equation of state for ordinary gases. By analogy, it is assumed that real macroisothermal curves in macrogases occur as real isothermal curves in ordinary gas

H. Morishita, L. S. Vlasenko, H. Tanaka, K. Semba

Electron paramagnetic resonance of ensembles of phosphorus donors in silicon has been detected electrically with externally applied magnetic fields lower than 200 G. Because the spin Hamiltonian was dominated by the contact hyperfine term rather than by the Zeeman terms at such low magnetic fields, superposition states $ α| \uparrow \downarrow >+β| \downarro

T. Y. Saito, R. Zanin, P. Bordas, V. Bosch-Ramon

Microquasars, X-ray binaries displaying relativistic jets driven by accretion onto a compact object, are some of the most efficient accelerators in the Galaxy. Theoretical models predict Very High Energy (VHE) emission at the base of the jet where particles are accelerated to multi-TeV energies. This emission could be detected by present IACTs. %Moreover, ga

Karsten Berger, Pratik Majumdar, Elina Lindfors, Fabrizio Tavecchio

The flat-spectrum radio-quasar 3C279 (z=0.536) is the most distant object detected at very high energy (VHE) gamma-rays. It is thus an important beacon for the study of the interaction of the VHE gamma-rays with the Extra-galactic Background Light (EBL). Previous observations by EGRET showed a highly variable flux that can differ up to a factor of 100. In th

K. Vida, K. Oláh, Zs. Kővári, H. Korhonen

We investigate the fast-rotating (P_orb=P_rot=0.465d), active dwarf binary V405 And (M0V+M5V) using photometric BV(RI)_C and optical spectroscopic data. The light variation is caused by the combined effect of spottedness and binarity with a small eclipse. We estimate the system parameters from the available light and radial velocity curves. Three flare event

Anouk Bergeron-Brlek, Christophe Hohlweg, Mike Zabrocki

Let V be a complex vector space with basis {x_1,x_2,...,x_n} and G be a finite subgroup of GL(V). The tensor algebra T(V) over the complex is isomorphic to the polynomials in the non-commutative variables x_1, x_2,..., x_n with complex coefficients. We want to give a combinatorial interpretation for the decomposition of T(V) into simple G-modules. In particu

E. Carmona, M. T. Costado, L. Font, J. Zapatero

Supernova Remnants (SNRs) are believed to be the acceleration sites of galactic cosmic rays. As such they are expected to produce Very High Energy (VHE) gamma-rays through hadronic and/or electromagnetic scenarios, hence they are natural targets for observations with ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs). Currently, VHE emission has b

Ian Tice

In this paper we study the time-dependent Ginzburg-Landau equations on a smooth, bounded domain $Ω\subset \Rn{2}$, subject to an electrical current applied on the boundary. The dynamics with an applied current are non-dissipative, but via the identification of a special structure in an interaction energy, we are able to derive a precise upper bound for the e

Moshe Marcus, Laurent Veron

We study the generalized boundary value problem for nonnegative solutions of $-Δu+g(u)=0$ in a bounded Lipschitz domain $\Gw$, when $g$ is continuous and nondecreasing. Using the harmonic measure of $\Gw$, we define a trace in the class of outer regular Borel measures. We amphasize the case where $g(u)=|u|^{q-1}u$, $q>1$. When $\Gw$ is (locally) a cone with

E. Carmona, J. A. Coarasa, M. Barcelo

MAGIC-I is currently the Imaging Cherenkov Telescope with the worldwide largest reflector currently in operation. The initially achieved low trigger threshold of 60 GeV has been further reduced by means of a novel trigger that allows the telescope to record gamma ray showers down to 25 GeV. The high trigger rate combined with the 2 GHz signal sampling rate r

Markus Garczarczyk, Markus Gaug, Angelo Antonelli, Denis Bastieri

MAGIC is currently the most suitable instrument to perform observations of the prompt an early afterglow emission from Gamma Ray Bursts (GRBs) at energies above 25 GeV. The instrument is designed to have the lowest possible energy threshold and fastest reaction time to GRB Coordinates Network (GCN) alerts. The MAGIC-I telescope started to follow-up GCN alert

Markus Gaug, Stefano Covino, Markus Garczarczyk, Angelo Antonelli

On January 2, the MAGIC-I Telescope observed GRB090102 (z=1.55) under particularly good observation conditions. Using the recently upgraded MAGIC-1 sum trigger system, upper limits down to below 50 GeV have been obtained. This is the first time that the new trigger system was fully exploited for a Gamma-ray Burst (GRB) observation and shows the capabilities

Joachim Schäfer, David Daems, Evgueni Karpov, Nicolas J. Cerf

We address the classical capacity of a quantum bosonic memory channel with additive noise, subject to an input energy constraint. The memory is modeled by correlated noise emerging from a Gauss-Markov process. Under reasonable assumptions, we show that the optimal modulation results from a &#34;quantum water-filling&#34; solution above a certain input energy

T. Birnstiel, C. P. Dullemond, F. Brauer

Context: Protoplanetary disks are observed to remain dust-rich for up to several million years. Theoretical modeling, on the other hand, raises several questions. Firstly, dust coagulation occurs so rapidly, that if the small dust grains are not replenished by collisional fragmentation of dust aggregates, most disks should be observed to be dust poor, which

T. Jogler, C. Delgado Mendez, M. T. Costado, W. Bednarek

Based on MAGIC observations from June and July 2007, we present upper limits to the E>140 GeV emission from the globular cluster M13. Those limits allow us to constrain the population of millisecond pulsars within M13 and to test models for acceleration of leptons inside their magnetospheres and/or surrounding. We conclude that in M13 either millisecond puls

Francisco M. Fernandez

We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first--order perturbation theory and by a more accurate variational approach. We show that it is greater than the one for the

Ivan Gatica Araus

In this article we develop the concepts of $σ$-relation and $σ$-function, following the same steps as in Set Theory. First we define the concept of ordered pair and then we build the Cartesian Product of $σ$-sets so that we can define the concepts of $σ$-relation and $σ$-function. Now, as in $σ$-Set Theory there exist the concepts of $σ$-antielement and $σ$-

Daniel Britzger, Emiliano Carmona, Pratik Majumdar, Oscar Blanch

The ground-based imaging atmospheric Cherenkov technique is currently the most powerful observation method for very high energy gamma rays. With its specially designed camera and readout system, the MAGIC Telescope is capable of observing also during nights with a comparatively high level of night-sky background light. This allows to extend the MAGIC duty cy

Frédéric Didier, Yann Laigle-Chapuy

We present one of the most efficient attacks against the combination generator. This attack is inherent to this system as its only assumption is that the filtering function has a good autocorrelation. This is usually the case if the system is designed to be resistant to other kinds of attacks. We use only classical tools, namely vectorial correlation, weight

Wei Chao, Zong-guo Si, Ya-juan Zheng, Shun Zhou

In the conventional type-(I+II) seesaw model, the effective mass matrix of three known light neutrinos is given by M_nu = M_L - M_D M^{-1}_R M^T_D in the leading-order approximation. We propose an intriguing scenario, in which the structural cancellation condition M_D M^{-1}_R M^T_D = 0 is guaranteed by the A_4 x Z_2 flavor symmetry. As a consequence, neutri

N. N. Kovaleva, Andrzej M. Oles, A. M. Balbashov, A. Maljuk

More discussion from the theory is suggested

Changhyun Ahn, Kyungsung Woo

We compute the spin-2 Kaluza-Klein modes around a warped product of AdS_4 and a seven-ellipsoid. This background with global G_2 symmetry is related to a U(N) x U(N) N=1 superconformal Chern-Simons matter theory with sixth order superpotential. The mass-squared in AdS_4 is quadratic in G_2 quantum number and KK excitation number. We determine the dimensions

V. A. Khoze, M. G. Ryskin, A. D. Martin

Central exclusive Higgs boson production, pp -> p+H+p, at the LHC can provide important complementary contribution to the comprehensive study of the Higgs sector in a remarkably clean topology. The bb(bar) Higgs decay mode is especially attractive, and for certain BSM scenarios may even become the discovery channel. Obvious requirements for the success of su

Pascal Chossat, Olivier Faugeras

We propose to use bifurcation theory and pattern formation as theoretical probes for various hypotheses about the neural organization of the brain. This allows us to make predictions about the kinds of patterns that should be observed in the activity of real brains through, e.g. optical imaging, and opens the door to the design of experiments to test these h

H. Wollny

Measuring single spin asymmetries in semi-inclusive deep-inelastic scattering (SIDIS) on a transversely polarized target gives a handle to investigate the transversity distribution and transverse momentum dependent distribution functions. In the years 2002, 2003 and 2004 COMPASS took data with a transversely polarized deuteron target and in the year 2007 wit

E. Leonardo, D. Bose, N. Mankuzhiyil, I. Oya

We present the results of the multiwavelength observation of the high frequency-peaked BL Lac object 1ES1426+428 carried in May-June 2008 with the KVA telescope for the optical band, the Swift and Suzaku satellites for the X-ray band and the MAGIC telescope for the very high energy band (E>100 GeV). The optical flux increased by 20% during the observation, w

Catherine Greenhill, Svante Janson, Andrzej Rucinski

Let G be a fixed connected multigraph with no loops. A random n-lift of G is obtained by replacing each vertex of G by a set of n vertices (where these sets are pairwise disjoint) and replacing each edge by a randomly chosen perfect matching between the n-sets corresponding to the endpoints of the edge. Let X_G be the number of perfect matchings in a random

Benjamin Dollet

The 2D flow of a foam confined in a Hele-Shaw cell through a contraction is investigated. Its rheological features are quantified using image analysis, with measurements of the elastic stress, rate of plasticity, and velocity. The behavior of the velocity strongly differs at the contraction entrance, where the flow is purely convergent, and at the contractio

V. A. Okorokov

The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on the all available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slopes is approximated by various analytic functions. The expanded &#34;standard&#34; logarithmic approximations

A. Moralejo, M. Gaug, E. Carmona, P. Colin

With the commissioning of the second MAGIC gamma-ray Cherenkov telescope situated close to MAGIC-I, the standard analysis package of the MAGIC collaboration, MARS, has been upgraded in order to perform the stereoscopic reconstruction of the detected atmospheric showers. MARS is a ROOT-based code written in C++, which includes all the necessary algorithms to

M. Blagojević, B. Cvetković

We introduce a natural set of asymptotic conditions in the spacelike stretched AdS sector of topologically massive gravity. The Poisson bracket algebra of the canonical generators is shown to have the form of the semi-direct sum of a $u(1)$ Kac-Moody and a Virasoro algebra, with central charges. Using the Sugawara construction, we prove that the asymptotic s

Peter Imkeller, Anthony Réveillac, Anja Richter

In this paper we consider a class of BSDEs with drivers of quadratic growth, on a stochastic basis generated by continuous local martingales. We first derive the Markov property of a forward--backward system (FBSDE) if the generating martingale is a strong Markov process. Then we establish the differentiability of a FBSDE with respect to the initial value of

R. Zanin, J. Cortina

The second MAGIC telescope, a clone of the first 17 m diameter MAGIC telescope, has entered the final commissioning phase and will soon start to take data, preferentially in the so-called stereo-mode. The control system for both telescopes is assigned to a number of autonomous functional units called subsystems. The control hardware and software components o

Y. Wiaux, G. Puy, Y. Boursier, P. Vandergheynst

We consider the probe of astrophysical signals through radio interferometers with small field of view and baselines with non-negligible and constant component in the pointing direction. In this context, the visibilities measured essentially identify with a noisy and incomplete Fourier coverage of the product of the planar signals with a linear chirp modulati

Thierry Petit, Emmanuel Poder

This research report presents an extension of Cumulative of Choco constraint solver, which is useful to encode over-constrained cumulative problems. This new global constraint uses sweep and task interval violation-based algorithms.

François Sausset, Cristina Toninelli, Giulio Biroli, Gilles Tarjus

We study bootstrap percolation (BP) on hyperbolic lattices obtained by regular tilings of the hyperbolic plane. Our work is motivated by the connection between the BP transition and the dynamical transition of kinetically constrained models, which are in turn relevant for the study of glass and jamming transitions. We show that for generic tilings there exis

S. A. Ali, C. Cafaro, S. Capozziello, Ch. Corda

We present a compact, self-contained review of the conventional gauge theoretical approach to gravitation based on the local Poincare group of symmetry transformations. The covariant field equations, Bianchi identities and conservation laws for angular momentum and energy-momentum are obtained.

Hong Huang

In this note we prove the backwards uniqueness of the mean curvature flow for (codimension one) hypersurfaces in a Euclidean space. More precisely, let $F_t, \widetilde{F}_t:M^n \rightarrow \mathbb{R}^{n+1}$ be two complete solutions of the mean curvature flow on $M^n \times [0,T]$ with bounded second fundamental forms. Suppose $F_T=\widetilde{F}_T$, then $F

Danny Bickson, Danny Dolev

We propose a new distributed algorithm for computing a truncated Newton method, where the main diagonal of the Hessian is computed using belief propagation. As a case study for this approach, we examine the sensor selection problem, a Boolean convex optimization problem. We form two distributed algorithms. The first algorithm is a distributed version of the

P. Carrasco, A. M. Cegarra, A. R. Garzón

This work contributes to clarifying several relationships between certain higher categorical structures and the homotopy type of their classifying spaces. Bicategories (in particular monoidal categories) have well understood simple geometric realizations, and we here deal with homotopy types represented by lax diagrams of bicategories, that is, lax functors

Fuminori Nakata

The LeBrun-Mason twistor correspondences for $S^1$-invariant self-dual Zollfrei metrics are explicitly established. We give explicit formulas for the general solutions of the wave equation and the monopole equation on the de Sitter three-space under the assumption for the tameness at infinity by using Radon-type integral transforms, and the above twistor cor