December 2008 arXiv papers — page 34

A. Georgakakis, D. L. Clements, G. Bendo, M. Rowan-Robinson

We use photometric data from Spitzer to explore the mid- and far-IR properties of 10 red QSOs (J-K>2, R-K>5) selected by combining the 2MASS in the NIR with the SDSS at optical wavelengths. Optical and/or near-infrared spectra are available for 8/10 sources. Modeling the SED from UV to far-IR shows that moderate dust reddening (A_V=1.3-3.2) can explain the r

Andreas S. Kronfeld

Recent measurements of the branching fraction for D_s -> l nu disagree with the Standard Model expectation, which relies on calculations of $f_{D_s}$ from lattice QCD. This paper uses recent preliminary measurements from CLEO and a new preliminary lattice-QCD result from this conference to update the significance of the discrepancy. The "f_{D_s} puzzle&#

Kishore N. Ananda, Sante Carloni, Peter K. S. Dunsby

We present for the first time the complete matter power spectrum for $R^n$ gravity which has been derived from the fourth order scalar perturbation equations. This leads to the discovery of a characteristic signature of fourth order gravity in the matter power spectrum, the details of which have not seen before in other studies in this area and therefore pro

Luck Darnière, Markus Junker

We study finitely generated free Heyting algebras from a topological and from a model theoretic point of view. We review Bellissima's representation of the finitely generated free Heyting algebra; we prove that it yields an embedding in the profinite completion, which is also the completion with respect to a naturally defined metric. We give an algebraic

Luck Darnière, Markus Junker

In this paper we introduce a notion of dimension and codimension for every element of a distributive bounded lattice $L$. These notions prove to have a good behavior when $L$ is a co-Heyting algebra. In this case the codimension gives rise to a pseudometric on $L$ which satisfies the ultrametric triangle inequality. We prove that the Hausdorff completion of

A. Cava, D. Bettoni, B. M. Poggianti, W. J. Couch

Aims. We present the results from a comprehensive spectroscopic survey of the WINGS (WIde-field Nearby Galaxy-cluster Survey) clusters, a program called WINGS-SPE. The WINGS-SPE sample consists of 48 clusters, 22 of which are in the southern sky and 26 in the north. The main goals of this spectroscopic survey are: (1) to study the dynamics and kinematics of

Stephan R. McCandliss

Concurrent observations of Lyman continuum (LyC) and Lyman-alpha (Lya) emission escaping from star-forming systems at low redshift are essential to understanding the physics of reionization at high redshift (z >~ 6). Some have suggested reionization is dominated by numerous small galaxies with LyC escape fractions f_e ~ 10%, while others suggest mini-quasars

John T. Griesmer

We unify and extend some previous results about cubic ergodic averages and sets of positive density in products of groups. This provides a joint generalization of earlier work of the author in the case of two commuting actions of an amenable group, and of Q. Chu's recent result on a a finite number of commuting transformations.

Jian Gao, B. W. Jiang, Aigen Li

Observationally, both the 3.4micron aliphatic hydrocarbon C--H stretching absorption feature and the 9.7micron amorphous silicate Si--O stretching absorption feature show considerable variations from the local diffuse interstellar medium (ISM) to Galactic center (GC): both the ratio of the visual extinction (A_V) to the 9.7micron Si--O optical depth (\tausil

B. W. Jiang, Ke Zhang, Aigen Li

The 21micron and 30micron bands are the strongest dust emission features detected in evolved low- and intermediate-mass C-rich stars (i.e. asymptotic giant branch [AGB] stars, proto-planetary nebulae [PPN], and planetary nebulae [PN]). While the 21micron feature is rare and exists only in the transient PPN phase, the 30micron feature is more common and seen

Jérôme Leroux

Arithmetic automata recognize infinite words of digits denoting decompositions of real and integer vectors. These automata are known expressive and efficient enough to represent the whole set of solutions of complex linear constraints combining both integral and real variables. In this paper, the closed convex hull of arithmetic automata is proved rational p

Chang Won Lee, Tyler L. Bourke, Philip C. Myers, Mike Dunham

This paper reports the discovery of a Very Low Luminosity Object (VeLLO) in the "starless" dense core L328, using the Spitzer Space Telescope and ground based observations from near-infrared to millimeter wavelengths. The Spitzer 8 micron image indicates that L328 consists of three subcores of which the smallest one may harbor a source, L328-IRS whil

Jérôme Leroux, Gregoire Sutre

Acceleration in symbolic verification consists in computing the exact effect of some control-flow loops in order to speed up the iterative fix-point computation of reachable states. Even if no termination guarantee is provided in theory, successful results were obtained in practice by different tools implementing this framework. In this paper, the accelerati

Mark Mahowald, Charles Rezk

We describe and compute the homotopy of spectra of topological modular forms of level 3. We give some computations related to the "building complex" associated to level 3 structures at the prime 2. Finally, we note the existence of a number of connective models of the spectrum TMF(Gamma_0(3)).

Theodore Choi, Ivan Shorubalko, Simon Gustavsson, Silke Schön

We report on correlated real-time detection of individual electrons in an InAs nanowire double quantum dot. Two self-aligned quantum point contacts in an underlying two-dimensional electron gas material serve as highly sensitive charge detectors for the double quantum dot. Tunnel processes of individual electrons and all tunnel rates are determined by simult

Dean Richardson

Photometry data were collected from the literature and analyzed for supernovae that are thought to have a gamma-ray burst association. There are several gamma-ray burst afterglow light curves that appear to have a supernova component. For these light curves, the supernova component was extracted and analyzed. A supernova light curve model was used to help de

W. A. Friedman, G. F. Bertsch

We explore the systematics of odd-even mass staggering with a view to identifying the physical mechanisms responsible. The BCS pairing and mean field contributions have A- and number parity dependencies which can help disentangle the different contributions. This motivates the two-term parametrization c_1 + c_2/A as a theoretically based alternative to the i

Anthony M. J. Davis, Eric Lauga

Laminar flow over a bubble mattress is expected to experience a significant reduction in friction since the individual surfaces of the bubbles are shear-free. However, if the bubbles are sufficiently curved, their protrusion into the fluid and along the flow direction can lead to an increase in friction as was recently demonstrated experimentally and computa

M. Prakash Pals

The multifaceted role of the density dependent nuclear symmetry energy in the nuclear astrophysics involving neutron stars is highlighted. Efforts toward a model independent determination of the dense matter equation state through a deconstruction of the neutron star structure equation utilizing the masses and radii of several individual neutron stars are de

D. A. Bahamon, A. L. C. Pereira, P. A. Schulz

We numerically investigate quantum rings in graphene and find that their electronic properties may be strongly influenced by the geometry, the edge symmetries and the structure of the corners. Energy spectra are calculated for different geometries (triangular, hexagonal and rhombus-shaped graphene rings) and edge terminations (zigzag, armchair, as well as th

Mark B. Wise, Vineer Bhansali

First passage models, where corporate assets undergo correlated random walks and a company defaults if its assets fall below a threshold provide an attractive framework for modeling the default process. Typical one year default correlations are small, i.e., of order a few percent, but nonetheless including correlations is very important, for managing portfol

Sheng Xi, Hongsheng Chen, Baile Zhang, Bae-Ian Wu

The method of coordinate transformation offers a way to realize perfect cloaks, but provides less ability to characterize the performance of a multilayered cloak in practice. Here, we propose an analytical model to predict the performance of a multilayered cylindrical cloak, based on which, the cloak in practice can be optimized to diminish the intrinsic sca

Kordian Lärz

In this paper we study weakly irreducible holonomy representations of the normal connection of a spacelike submanifold in a pseudo-Riemannian space from. We associate screen representations to weakly irreducible normal holonomy groups and classify the screen representations having the Borel-Lichnérowicz property. In particular, we derive a classification of

M. L. Glasser

This note presents selected values of definite integrals whose integrand contains a power of the Dedekind function having imaginary argument.

Dina Zhabinskaya, Jesse M. Kinder, E. J. Mele

We calculate the Casimir interaction between two short range scatterers embedded in a background of one dimensional massless Dirac fermions using a force operator approach. We obtain the force between two finite width square barriers, and take the limit of zero width and infinite potential strength to study the Casimir force mediated by the fermions. For the

P. Watson, H. Reinhardt

The Slavnov-Taylor identities of Coulomb gauge Yang-Mills theory are derived from the (standard, second order) functional formalism. It is shown how these identities form closed sets from which one can in principle fully determine the Green's functions involving the temporal component of the gauge field without approximation, given appropriate input.

Gladys León

We investigate the Hall effect in two different theoretical models of strongly correlated systems: a system made of weakly coupled Luttinger liquids, in the presence of umklapp scattering, and the 2D triangular lattice, with nearest-neighbor hopping and a local Hubbard interaction. In the first model we use a memory function approach to compute the Hall coef

Sanjoy Datta, Sudhakar Yarlagadda

We derive an effective d-dimensional Hamiltonian for a system of hard-core-bosons coupled to optical phonons in a lattice. Away from half-filling, we show that the presence of next-nearest-neighbor hopping in the effective Hamiltonian leads to a superfluid-to-supersolid transition at intermediate boson-phonon (b-p) couplings, while at strong-couplings the sy

Eric Feron, Fernando Alegre

The analysis and proper documentation of the properties of closed-loop control software presents many distinct aspects from the analysis of the same software running open-loop. Issues of physical system representations arise, and it is desired that such representations remain independent from the representations of the control program. For that purpose, a co

Earl Schulz

Exact analytical solutions are given for the three finite disks with surface density $Σ_n=σ_0 (1-R^2/α^2)^{n-1/2} \textrm{with} n=0, 1, 2$. Closed-form solutions in cylindrical co-ordinates are given using only elementary functions for the potential and for the gravitational field of each of the disks. The n=0 disk is the flattened homeoid for which $Σ_{hom}

Roberto Casalbuoni, Federico Elmetti, Joaquim Gomis, Kiyoshi Kamimura

We study some algebraic properties of the 'vector supersymmetry' (VSUSY) algebra, a graded extension of the four-dimensional Poincare' algebra with two odd generators, a vector and a scalar, and two central charges. The anticommutator between the two odd generators gives the four-momentum operator, from which the name vector supersymmetry. We construct the C

Rafael Ferraro, Franco Fiorini

Using the Teleparallel Equivalent of General Relativity formulated in Weitzenböck spacetime, we thoroughly explore a kind of Born-Infeld regular gravity leading to second order field equations for the vielbein components. We explicitly solve the equations of motion for two examples: the extended BTZ black hole, which results to exist even if the cosmological

Diego Sáez-Gómez

Scalar-tensor theories are studied in the context of cosmological evolution, where the expansion history of the Universe is reconstructed. It is considered quintessence/phantom models, where inflation and cosmic acceleration are reproduced. Also, the non-minimally coupling regime between the scalar field and the Ricci scalar is studied and cosmological solut

Slavcho Shtrakov, Klaus Denecke

The study of essential and strongly essential variables in functions defined on finite sets is a part of $k$-valued logic. We extend the main definitions from functions to terms. This allows us to apply concepts and results of Universal Algebra. On the basis of the concept of a separable set of variables in a term we introduce a new notion of complexity of t

Alfonso V. Ramallo, Jonathan P. Shock, Dimitrios Zoakos

We study the addition of flavor to the gravity dual of N=4 three-dimensional gauge theories obtained by wrapping $N_c$ D4-branes on a two-cycle of a non-compact Calabi-Yau two-fold. In this setup the flavor is introduced by adding another set of D4-branes that are extended along the non-compact directions of the Calabi-Yau which are normal to the cycle which

A. D'Ai, R. Iaria, T. Di Salvo, G. Matt

We present the preliminary results of a 50 ks long XMM-Newton observation of the bright Z-source GX 340+0. In this Letter we focus on the study of a broad asymmetric emission line in the Fe K alpha energy band, whose shape is clearly resolved and compatible with a relativistically smeared profile arising from reflection on a hot accretion disk extending clos

S. Das Gupta

The canonical thermodynamic model has been used frequently to describe the disassembly of hot nuclear matter consisting of neutrons and protons. Such matter is formed in intermediate energy heavy ion collisions. Here we extend the method to include, in addition to neutrons and protons, lambda particles. This allows us to include productions of hypernuclei in

Michal Svanda, Mirek Klvana, Michal Sobotka, Alexander G. Kosovichev

In the recent papers, we introduced a method utilised to measure the flow field. The method is based on the tracking of supergranular structures. We did not precisely know, whether its results represent the flow field in the photosphere or in some sub-photospheric layers. In this paper, in combination with helioseismic data, we are able to estimate the depth

Jose Beltran Jimenez, Antonio L. Maroto

We show that vector theories on cosmological scales are excellent candidates for dark energy. We consider two different examples, both are theories with no dimensional parameters nor potential terms, with natural initial conditions in the early universe and the same number of free parameters as LCDM. The first one exhibits scaling behaviour during radiation

Jianya Liu, Yonghui Wang

Let $K$ be an algebraic number field, and $π=\otimesπ_{v}$ an irreducible, automorphic, cuspidal representation of $\GL_{m}(\mathbb{A}_{K})$ with analytic conductor $C(π)$. The theorem on analytic strong multiplicity one established in this note states, essentially, that there exists a positive constant $c$ depending on $\varepsilon>0, m,$ and $K$ only, such

John T. Griesmer

We find limits of some multiple ergodic averages, generalizing a result of Bergelson to the setting of two commuting transformations and actions of amenable groups.

Florent Bouchy, Alain Finkel, Jérôme Leroux

We tackle the issue of representing infinite sets of real- valued vectors. This paper introduces an operator for combining integer and real sets. Using this operator, we decompose three well-known logics extending Presburger with reals. Our decomposition splits a logic into two parts : one integer, and one decimal (i.e. on the interval [0,1]). We also give a

Makoto Kishimoto, Sebastian F. Hoenig, Konrad R. W. Tristram, Gerd Weigelt

We present a quantitative and relatively model-independent way to assess the radial structure of nearby AGN tori. These putative tori have been studied with long-baseline infrared (IR) interferometry, but the spatial scales probed are different for different objects. They are at various distances and also have different physical sizes which apparently scale

K. Fukaya, Y. -G. OH, H. Ohta, K. Ono

The purpose of this paper is two-fold. First we explain the construction of the canonical model of filtered $A_\infty$-algebras given in the authors' book [FOOO]. The canonical model plays a crucial role in the study of Lagrangian Floer theory on toric manifolds in our recent papers, arXiv:0802.1703 and arXiv:0810.5654. Then using a variation of the argu

K. Zwintz, T. Kallinger, D. B. Guenther, M. Gruberbauer

We present precise photometry of the pulsating Herbig Ae star HD 142666 obtained in two consecutive years with the MOST (Microvariability & Oscilations of STars) satellite. Previously, only a single pulsation period was known for HD 142666. The MOST photometry reveals that HD 142666 is multi-periodic. However, the unique identification of pulsation frequenci

Robin W Tucker

Properties of a fundamental double-form of bi-degree $(p,p)$ for $p\ge 0$ are reviewed in order to establish a distributional framework for analysing equations of the form $$ΔΦ+ λ^2 Φ= {\cal S} $$ where $Δ$ is the Hodge-de Rham operator on $p-$forms $ Φ$ on ${\bf R}^3$. Particular attention is devoted to singular distributional solutions that arise when the

Marco Mackaay, Pedro Vaz

In this paper we compute the reduced HOMFLY-PT homologies of the Conway and the Kinoshita-Terasaka knots and show that they are isomorphic.

I. Mazilu, H. T. Williams

A two-temperature linear spin model is presented that allows an easily understandable introduction to non-equilibrium statistical physics. The model is one that includes the concepts that are typical of more realistic non-equilibrium models but that allows straightforward steady state solutions and, for small systems, development of the full time dependence

I. V. Pylyuk, M. P. Kozlovskii

The microscopic approach to calculating the free energy of a three-dimensional Ising-like system in a homogeneous external field is developed in the higher non-Gaussian approximation (the $ρ^6$ model) at temperatures above the critical value of $T_c$ ($T_c$ is the phase-transition temperature in the absence of an external field). The free energy of the syste

Grant Duncan McGregor

In this thesis we examine the method of counting $B\overline{B}$ events produced in the BaBar experiment. The original method was proposed in 2000, but improvements to track reconstruction and our understanding of the detector since that date make it appropriate to revisit the $B$ Counting method. We propose a new set of cuts designed to minimize the sensiti

Daniel Pena Arteaga, E. Khan, Peter Ring

The E1 strength is systematically analyzed in very neutron-rich Sn nuclei, beyond $^{132}$Sn until $^{166}$Sn, within the Relativistic Quasiparticle Random Phase Approximation. The great neutron excess favors the appearance of a deformed ground state for $^{142-162}$Sn. The evolution of the low-lying strength in deformed nuclei is determined by the interplay

Alain Finkel, Jérôme Leroux

Number Decision Diagrams (NDD) provide a natural finite symbolic representation for regular set of integer vectors encoded as strings of digit vectors (least or most significant digit first). The convex hull of the set of vectors represented by a NDD is proved to be an effectively computable convex polyhedron.

W. B. Vasantha Kandasamy, Florentin Smarandache

With the advent of computers, one needs algebraic structures that can simultaneously work with bulk data. One such algebraic structure, namely, n-linear algebras of type I are introduced in this book and its applications to n-Markov chains and n-Leontief models are given. These structures can be thought of as the generalization of bilinear algebras and bivec

Finn Macleod, James Gleeson

We obtain an index of the complexity of a random sequence by allowing the role of the measure in classical probability theory to be played by a function we call the generating mechanism. Typically, this generating mechanism will be a finite automata. We generate a set of biased sequences by applying a finite state automata with a specified number, $m$, of st

A. Nicolaidis

The unification of Quantum Mechanics and General Relativity remains the primary goal of Theoretical Physics, with string theory appearing as the only plausible unifying scheme. In the present work, in a search of the conceptual foundations of string theory, we analyze the relational logic developed by C. S. Peirce in the late nineteenth century. The Peircean

M. Gonzalez-Alonso, A. Pich, J. Prades

A sum rule analysis of the hadronic tau-decay data can be used to determine the low-energy constants L10(mu) and C87(mu). These constants are QCD chiral-order parameters, which appear at order p^4 and p^6, respectively, in the chiral perturbation theory expansion of the V-A correlator. At order p^4 we obtain L10(M_rho) = -(5.22\pm 0.06)10^-3. Including in th

Baybars Külebi, Stefan Jordan, Fabian Euchner, Heiko Hirsch

We have calculated optical spectra of hydrogen-rich (DA) white dwarfs with magnetic field strengths between 1 MG and 1000 MG for temperatures between 7000 K and 50000 K. Through a least-squares minimization scheme with an evolutionary algorithm, we have analyzed the spectra of 114 magnetic DAs from the SDSS (95 previously published plus 14 newly discovered w

A. Bessa, C. A. A. de Carvalho, E. S. Fraga

We present a unified formulation for quantum statistical physics based on the representation of the density matrix as a functional integral. We identify the stochastic variable of the effective statistical theory that we derive as a boundary configuration and a zero mode relevant to the discussion of infrared physics. We illustrate our formulation by computi

Gia Dvali, Cesar Gomez

We show that lowering of the gravitational cutoff relative to the Planck mass, imposed by black hole physics in theories with N species, has an independent justification from quantum information theory. First, this scale marks the limiting capacity of any information processor. Secondly, by taking into the account the limitations of the quantum information s

Henryk Czyz, Agnieszka Grzelinska, Agnieszka Wapienik

A review of the status of the Monte Carlo event generator PHOKHARA, developed for experiments using the radiative return method. The four-pion production in electron-positron annihilation and in tau-lepton decays and the narrow resonances studies are described.

Godofredo Iommi, Jan Kiwi

We characterize one-dimensional compact repellers having nonconcave Lyapunov spectra. For linear maps with two branches we give an explicit condition that characterizes non-concave Lyapunov spectra.

Alessandro Portaluri

Sturm theory for second order differential equations was generalized to systems and higher order equations with positive leading coefficient by several authors. Here we propose a Sturm oscillation theorem for indefinite systems of even order and with Dirichlet boundary conditions having strongly indefinite leading term.

Fabien Alet, Daniel Braun, Grégoire Misguich

In a recent Letter [Phys. Rev. Lett. 99, 170502 (2007); quant-ph/0703227], Chandran and coworkers study the entanglement properties of valence bond (VB) states. Their main result is that VB states do not contain (or only an insignificant amount of) two-site entanglement, whereas they possess multi-body entanglement. Two examples ("RVB gas and liquid"

Giovanna Tinetti, Jean-Philippe Beaulieu

We have entered the phase of extrasolar planets characterization, probing their atmospheres for molecules, constraining their horizontal and vertical temperature profiles and estimating the contribution of clouds and hazes. We report here a short review of the current situation using ground based and space based observations, and present the transmission spe

Alexandre Faribault, Pasquale Calabrese, Jean-Sebastien Caux

Understanding the non-equilibrium dynamics of extended quantum systems after the trigger of a sudden, global perturbation (quench) represents a daunting challenge, especially in the presence of interactions. The main difficulties stem from both the vanishing time scale of the quench event, which can thus create arbitrarily high energy modes, and its non-loca

Alexei D. Kiselev, Vladimir G. Chigrinov, Hoi-Sing Kwok

We study the kinetics of photoinduced ordering in the azo-dye SD1 photoaligning layers and present the results of modeling performed using two different phenomenological approaches. A phenomenological two state model is deduced from the master equation for an ensemble of two-level molecular systems. Using an alternative approach, we formulate the two-dimensi

Rodislav Driben, Boris A. Malomed

It is known that optical-lattice (OL) potentials can stabilize solitons and solitary vortices against the critical collapse, generated by the cubic attractive nonlinearity in the 2D geometry. We demonstrate OLs can also stabilize various species of fundamental and vortical solitons against the super-critical collapse, driven by the double-attractive cubic-qu

Christian Sommer, Laurens D. van Buuren, Michael Motsch, Sebastian Pohle

We describe the combination of buffer-gas cooling with electrostatic velocity filtering to produce a high-flux continuous guided beam of internally cold and slow polar molecules. In a previous paper (L.D. van Buuren et al., arXiv:0806.2523v1) we presented results on density and state purity for guided beams of ammonia and formaldehyde using an optimized set-

ANITA collaboration, P. Gorham, P. Allison, S. Barwick

We present a detailed report on the experimental details of the Antarctic Impulsive Transient Antenna (ANITA) long duration balloon payload, including the design philosophy and realization, physics simulations, performance of the instrument during its first Antarctic flight completed in January of 2007, and expectations for the limiting neutrino detection se

Gyula Fodor, Péter Forgács, Zalán Horváth, Márk Mezei

The radiation loss of small amplitude oscillons (very long-living, spatially localized, time dependent solutions) in one dimensional scalar field theories is computed in the small-amplitude expansion analytically using matched asymptotic series expansions and Borel summation. The amplitude of the radiation is beyond all orders in perturbation theory and the

Karin I. Oberg, Harold Linnartz, Ruud Visser, Ewine F. van Dishoeck

Gaseous H2O has been detected in several cold astrophysical environments, where the observed abundances cannot be explained by thermal desorption of H2O ice or by H2O gas phase formation. These observations hence suggest an efficient non-thermal ice desorption mechanism. Here, we present experimentally determined UV photodesorption yields of H2O and D2O ice

Matthew Alpert, Elie Feder, Heiko Harborth

We extend known results regarding the maximum rectilinear crossing number of the cycle graph (C_n) and the complete graph (K_n) to the class of general d-regular graphs R_{n,d}. We present the generalized star drawings of the d-regular graphs S_{n,d} of order n where n+d= 1 mod 2 and prove that they maximize the maximum rectilinear crossing numbers. A star-l

Wouter Gelade, Marcel Marquardt, Thomas Schwentick

The paper investigates the power of the dynamic complexity classes DynFO, DynQF and DynPROP over string languages. The latter two classes contain problems that can be maintained using quantifier-free first-order updates, with and without auxiliary functions, respectively. It is shown that the languages maintainable in DynPROP exactly are the regular language

F. G. Paauw, A. Fedorov, C. J. P. M. Harmans, J. E. Mooij

We experimentally demonstrate the in situ tunability of the minimum energy splitting (gap) of a superconducting flux qubit by means of an additional flux loop. Pulses applied via a local control line allow us to tune the gap over a range of several GHz on a nanosecond timescale. The strong flux sensitivity of the gap (up to 0.7 GHz/mPhi_0) opens up the possi

Stefan Berge, Werner Bernreuther

We propose a method for determining the CP nature of a neutral Higgs boson or spin-zero resonance $ϕ$ at the CERN Large Hadron Collider (LHC) in its $ϕ\toτ^{-}τ^{+}$ decay channel. The method can be applied to any 1-prong $τ$-decay mode, which comprise the majority of the $τ$-lepton decays. The proposed observables allow to discriminate between pure scalar a

Robert Kooij, Phillip Schumm, Caterina Scoglio

The robustness of a network is depending on the type of attack we are considering. In this paper we focus on the spread of viruses on networks. It is common practice to use the epidemic threshold as a measure for robustness. Because the epidemic threshold is inversely proportional to the largest eigenvalue of the adjacency matrix, it seems easy to compare th

Marik Barnabé Heider, Carla Cattadori, Oleg Chkvorets, Assunta Di Vacri

The GERmanium Detector Array, GERDA, will search for neutrinoless double beta decay in 76Ge at the National Gran Sasso Laboratory of the INFN. Bare high-purity germanium detectors enriched in 76Ge will be submerged in liquid argon serving simultaneously as a shield against external radioactivity and as a cooling medium. In GERDA Phase-I, reprocessed enriched

Mikhail V. Medvedev, Olga V. Zakutnyaya

Cosmic rays accelerated by a shock form a streaming distribution of outgoing particles in the foreshock region. If the ambient fields are negligible compared to the shock and cosmic ray energetics, a stronger magnetic field can be generated in the shock upstream via the streaming (Weibel-type) instability. Here we develop a self-similar model of the foreshoc

Barbara Betz, Jorge Noronha, Miklos Gyulassy, Giorgio Torrieri

We compare away-side hadron correlations with respect to tagged heavy quark jets computed within a weakly coupled pQCD and a strongly coupled AdS/CFT model. While both models feature similar far zone Mach and diffusion wakes, the far zone stress features are shown to be too weak to survive thermal broadening at hadron freeze-out. Observable away-side conical

Luca Chiantini, Ciro Ciliberto

We generalize Zak's theorems on tangencies and on linear normality as well as Zak's definition and classification of Severi varieties. In particular we find sharp lower bounds for the dimension of higher secant varieties of a given variety X under suitable regularity assumption on X, and we classify varieties for which the bound is attained.

Francisco D. Mazzitelli, Fernando C. Lombardo, Paula I. Villar

We present an overview of the validity of the Proximity Force Approximation (PFA) in the calculation of Casimir forces between perfect conductors for different geometries, with particular emphasis for the configuration of a cylinder in front of a plane. In all cases we compare the exact numerical results with those of PFA, and with asymptotic expansions that

Pavel Gabor, Peter A. Schuller, Bruno Chazelas, Michel Decaudin

The achromatic phase shifter (APS) is a component of the Bracewell nulling interferometer studied in preparation for future space missions (viz. Darwin/TPF-I) focusing on spectroscopic study of Earth-like exo-planets. Several possible designs of such an optical subsystem exist. Four approaches were selected for further study. Thales Alenia Space developed a

S. Osborne, K. Buckley, A. Amann, S. O'Brien

We study the injection locking bistability of a specially engineered two-color semiconductor Fabry-Perot laser. Oscillation in the uninjected primary mode leads to a bistability of single mode and two-color equilibria. With pulsed modulation of the injected power we demonstrate an all-optical memory element based on this bistability, where the uninjected pri

J. Blümlein, D. Robaschik, B. Geyer

The quantum field theoretic treatment of inclusive deep--inelastic diffractive scattering given in a previous paper \cite{BGR2006} is discussed in detail using an equivalent formulation with the aim to derive a representation suitable for data analysis. We consider the off-cone twist--2 light-cone operators to derive the target mass and finite $t$ correction

Guy Wallet

In some scientific fields, a scaling is able to modify the topology of an observed object. Our goal in the present work is to introduce a new formalism adapted to the mathematical representation of this kind of phenomenon. To this end, we introduce a new metric structure - the galactic spaces - which depends on an ordered field extension of R. Moreover, some

Artur Kwasniowski, Janusz Adamowski

The effect of external electric field on the exchange interaction has been studied by an exact diagonalization method for two electrons in laterally coupled quantum dots (QD's). We have performed a systematic study of several nanodevices that contain two gate-defined QD's with different shapes and sizes located between source and drain contacts. The

Stéphane Sacuto, Olivier Chesneau

The symbiotic system HM Sagittae consists of a Mira star and a secondary White Dwarf component. The dust content of the system was severely affected by the nova outburst in 1975, which is still ongoing. The capabilities of optical interferometry operating in the mid-IR allow us to investigate the current geometry of the dust envelope. We test our previous sp

Alessandro Giuffrida, Davide Valenti, Graziella Ziino, Bernardo Spagnolo

The present paper discusses the use of modified Lotka-Volterra equations in order to stochastically simulate the behaviour of Listeria monocytogenes and Lactic Acid Bacteria (LAB) during the fermentation period (168 h) of a typical Sicilian salami. For this purpose, the differential equation system is set considering T, pH and aw as stochastic variables. Eac

Pierre Le Doussal, Kay Jörg Wiese

Interfaces pinned by quenched disorder are often used to model jerky self-organized critical motion. We study static avalanches, or shocks, defined here as jumps between distinct global minima upon changing an external field. We show how the full statistics of these jumps is encoded in the functional-renormalization-group fixed-point functions. This allows u

J. -R. Cudell, O. V. Selyugin

It is very likely that hadronic scattering will enter a new regime at the LHC, as the black-disk limit is reached. This will lead to a severe change in the t dependence of the real part and of the slope of the elastic scattering amplitude, and in turn this may bias the measurement of the total cross section. We examine this issue, and suggest new strategies

A. B. Balakin, R. K. Muharlyamov

A three-parameter toy-model, which describes a non-minimal coupling of gravity field with electromagnetic field of a relativistic two-component electrically neutral plasma, is discussed. Resonance interactions between particles and transversal waves in plasma are shown to take place due to the curvature coupling effect.

Roy Maartens, Kevin Vandersloot

We examine the dynamical consequences of homogeneous cosmological magnetic fields in the framework of loop quantum cosmology. We show that a big-bounce occurs in a collapsing magnetized Bianchi I universe, thus extending the known cases of singularity-avoidance. Previous work has shown that perfect fluid Bianchi I universes in loop quantum cosmology avoid th

Carlo Giunti

The claims that the GSI time anomaly is due to the mixing of neutrinos in the final state of the observed electron-capture processes are refuted. With the help of an analogy with a double-slit experiment, it is shown that the standard method of calculation of the rate of an interaction process by adding the rates of production of all the allowed final states

F. Francica, S. Maniscalco, J. Piilo, F. Plastina

We provide an exact and complete characterization of the entanglement dynamics of two qubits coupled to a common structured reservoir at zero temperature. We derive the conditions to maximize reservoir-induced entanglement for an initially factorized state of the two-qubit system. In particular, when the two qubits are placed inside a lossy cavity, we show t

Nelly Point, Silvano Erlicher

A new description of the endochronic and the Mroz model is discussed. It is based on the definition of a suitable pseudo-potential and the use of the generalized normality assumption. The key-point of this formulation is the dependence of the pseudo-potentials on state variables.

Silvano Erlicher, Nelly Point

A simple way to define the flow rules of plasticity models is the assumption of generalized normality associated with a suitable pseudo-potential function. This approach, however, is not usually employed to formulate endochronic theory and non-linear kinematic (NLK) hardening rules as well as generalized plasticity models. In this paper, generalized normalit

Angel Ballesteros, Alberto Enciso, Francisco J. Herranz, Orlando Ragnisco

The N-dimensional Hamiltonian H formed by a curved kinetic term (depending on a function f), a central potential (depending on a function U), a Dirac monopole term, and N centrifugal terms is shown to be quasi-maximally superintegrable for any choice of the functions f and U. This result is proven by making use of the underlying sl(2,R)-coalgebra symmetry of

Elisabetta Semboloni, Ismael Tereno, Ludovic van Waerbeke, Catherine Heymans

The current methods available to estimate gravitational shear from astronomical images of galaxies introduce systematic errors which can affect the accuracy of weak lensing cosmological constraints. We study the impact of KSB shape measurement bias on the cosmological interpretation of tomographic two-point weak lensing shear statistics. We use a set of real

Matthew P. Peloso, Ilja Gerhardt, Caleb Ho, Antia Lamas-Linares

Many quantum key distribution (QKD) implementations using a free space transmission path are restricted to operation at night time in order to distinguish the signal photons used for a secure key establishment from background light. Here, we present a lean entanglement-based QKD system overcoming that imitation. By implementing spectral, spatial and temporal

Stephen Parke, Hisakazu Minakata, Hiroshi Nunokawa, Renata Zukanovich Funchal

We show how one could determine the neutrino mass hierarchy with Mossbauer neutrinos and also revisit the question of whether the hierarchy can be determined with reactor neutrinos.