April 2010 arXiv papers — page 5

Émilien Azema, Farhang Radjaï

We present a numerical analysis of the effect of particle elongation on the quasistatic behavior of sheared granular media by means of the Contact Dynamics method. The particle shapes are rounded-cap rectangles characterized by their elongation. The macroscopic and microstructural properties of several packings subjected to biaxial compression are analyzed a

Nicolas Creton, Virgil Optasanu, Sébastien Garruchet, Tony Montesin

The growth of a U3O7 oxide layer during the anionic oxidation of UO2 pellets induced very important mechanical stresses due to the crystallographic lattice parameters differences between UO2 and its oxide. These stresses, combined with the chemical processes of oxidation, can lead to the cracking of the system, called chemical fragmentation. We study the cry

Tang lin

In this paper, we study weighted local Hardy spaces $h^p_\wz(\rz)$ associated with local weights which include the classical Muckenhoupt weights. This setting includes the classical local Hardy space theory of Goldberg \cite{g}, and the weighted Hardy spaces of Bui \cite{bu}.

Jean-Michel Billiot, Franck Corset, Eric Fontenas

In the present study, we establish the existence of nontrivial site percolation threshold in the Relative Neighborhood Graph (RNG) for Poisson stationary point process with unit intensity in the plane.

Quentin Bodart, Sébastien Merlet, Nicola Malossi, Franck Pereira Dos Santos

We demonstrate a scheme for realizing a compact cold atom gravimeter. The use of a hollow pyramidal configuration allows to achieve all functions: trapping, interferometer and detection with a unique laser beam leading to a drastic reduction in complexity and volume. In particular, we demonstrate a relative sensitivity to acceleration of gravity (g) of 1.7 x

N. B. Kopnin, Y. M. Galperin, V. M. Vinokur

Coherent charge transfer through a ballistic gated SINIS junction is mediated by the resonant tunneling via the Andreev states. Extra charge accommodated on the Andreev levels partially compensates the charge induced by the gate voltage preserving the electron wavelength and maintaining the resonance conditions in a broad range of gate voltages. As a result,

Gustavo Dotti, Julio Oliva, Ricardo Troncoso

The classification of certain class of static solutions for the Einstein-Gauss-Bonnet theory in vacuum is performed in $d\geq5$ dimensions. The class of metrics under consideration is such that the spacelike section is a warped product of the real line and an arbitrary base manifold. It is shown that for a generic value of the Gauss-Bonnet coupling, the base

Guillaume Chèze

The extended Lüroth's Theorem says that if the transcendence degree of $\KK(\mathsf{f}_1,\dots,\mathsf{f}_m)/\KK$ is 1 then there exists $f \in \KK(\underline{X})$ such that $\KK(\mathsf{f}_1,\dots,\mathsf{f}_m)$ is equal to $\KK(f)$. In this paper we show how to compute $f$ with a probabilistic algorithm. We also describe a probabilistic and a determini

Remi Baron, Philippe Boucaud, Jaume Carbonell, Albert Deuzeman

We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at two values of the lattice spacing a~0.078 fm and a~0.086 fm with lattice sizes ranging from L~1.9 f

O. V. Ershova, I. V. Lebedeva, Yu. E. Lozovik, A. M. Popov

Multi-scale simulations of nanotube-based nanoelectromechanical systems (NEMS) controlled by a nonuniform electric field are performed by an example of a gigahertz oscillator. Using molecular dynamics simulations, we obtain the friction coefficients and characteristics of the thermal noise associated with the relative motion of the nanotube walls. These resu

Gurjav Ganbold

We estimate the QCD effective charge $α_s$ in the low-energy region by exploiting the conventional meson spectrum within a relativistic quantum-field model based on analytic confinement. The ladder Bethe-Salpeter equation is solved for the masses of two-quark bound states. We found a new, independent and specific infrared-finite behavior of QCD coupling belo

Matthias Scheid, Dario Bercioux, Klaus Richter

The concept of ratchets, driven asymmetric periodic structures giving rise to directed particle flow, has recently been generalized to a quantum ratchet mechanism for spin currents mediated through spin-orbit interaction. Here we consider such systems in the coherent mesoscopic regime and generalize the proposal of a minimal spin ratchet model based on a non

Rytis Jursenas, Gintaras Merkelis

In the present paper by using Mathematica system a symbolic programming method for generation of the expressions of the expansion terms of atomic stationary perturbation theory (PT) is presented. For this purpose, the package named as NCoperators was developed. In producing the PT terms, this package accommodates the features of the Rayleigh-Schrödinger pert

Jean-Yves Baudais, Fahad Syed Muhammad, Jean-François Hélard

Bit error rate (BER) minimization and SNR-gap maximization, two robustness optimization problems, are solved, under average power and bit-rate constraints, according to the waterfilling policy. Under peak-power constraint the solutions differ and this paper gives bit-loading solutions of both robustness optimization problems over independent parallel channel

Matthias Hamann, Fabian Hundertmark

We classify the connected-homogeneous digraphs with more than one end. We further show that if their underlying undirected graph is not connected-homogeneous, they are highly-arc-transitive.

Yves Coudene, Barbara Schapira

We give examples of rank one compact surfaces on which there exist recurrent geodesics that cannot be shadowed by periodic geodesics. We build rank one compact surfaces such that ergodic measures on the unit tangent bundle of the surface are not dense in the set of probability measures invariant by the geodesic flow. Finally, we give examples of complete ran

Holger S. P. Mueller

Astronomical observations toward Sagittarius B2(M) as well as other sources with APEX have recently suggested that the rest frequency of the J = 1 - 0 transitions of 13CH+ is too low by about 80 MHz. Improved rest frequencies of isotopologs of methylidynium should be derived to support analyses of spectral recording obtained with the ongoing Herschel mission

Vincent Colin, Emmanuel Ferrand, Petya Pushkar

We show that there is no positive loop inside the component of a fiber in the space of Legendrian embeddings in the contact manifold $ST^*M$, provided that the universal cover of $M$ is $\RM^n$. We consider some related results in the space of one-jets of functions on a compact manifold. We give an application to the positive isotopies in homogeneous neighbo

Anton Bondarenko

In this paper the approach to solving several combinatorial optimization problems using the local search and the genetic algorithm techniques is proposed. Initially this approach was developed in purpose to overcome some difficulties inhibiting the application of above mentioned techniques to the problems of the Questionnaire Theory. But when the algorithms

Rytis Jursenas, Gintaras Merkelis

General formulas of the two-electron operator representing either atomic or effective interactions are given in a coupled tensorial form in relativistic approximation. The alternatives of using uncoupled, coupled and antisymmetric two-electron wave functions in constructing coupled tensorial form of the operator are studied. The second quantization technique

Joakim Edsjo, Annika H. G. Peter

Recently, several papers have appeared that examine the process of capturing dark-matter particles from the Galactic halo to orbits bound to the Solar System. The authors of these papers predict large enhancements to the local dark-matter density via gravitational three-body interactions with planets. However, these conclusions are wrong; these papers do not

Pierre Lescanne, Perrinel Matthieu

Escalation is a typical feature of infinite games. Therefore tools conceived for studying infinite mathematical structures, namely those deriving from coinduction are essential. Here we use coinduction, or backward coinduction (to show its connection with the same concept for finite games) to study carefully and formally the infinite games especially those c

Swan Dubois, Toshimitsu Masuzawa, Sébastien Tixeuil

A self-stabilizing protocol provides by definition a tolerance to transient failures. Recently, a new class of self-stabilizing protocols appears. These protocols provides also a tolerance to a given number of permanent failures. In this article, we are interested in self-stabilizing protocols that deal with Byzantines failures. We prove that, for some probl

Augustin Fruchard, Reinhard Schäfke

We develop the theory of a new type of asymptotic expansions for functions of two variables the coefficients of which contain functions of one of the variables as well as functions of the quotient of these two variables. These combined asymptotic expansions (DAC) are particularly well suited for the description of solutions of singularly perturbed ordinary d

D. Heyner, D. Schmitt, J. Wicht, K. -H. Glassmeier

Various possibilities are currently under discussion to explain the observed weakness of the intrinsic magnetic field of planet Mercury. One of the possible dynamo scenarios is a dynamo with feedback from the magnetosphere. Due to its weak magnetic field Mercury exhibits a small magnetosphere whose subsolar magnetopause distance is only about 1.7 Hermean rad

Angel R. Lopez-Sanchez, Cesar Esteban

We have performed a comprehensive multiwavelength analysis of a sample of 20 starburst galaxies that show a substantial population of very young massive stars, most of them classified as Wolf-Rayet (WR) galaxies. We have analysed optical/NIR colours, physical and chemical properties of the ionized gas, stellar, gas and dust content, star-formation rate and i

R. M. Vogt

We show that a map between fibrant objects in a closed model category is a weak equivalence if and only if it has the right homotopy extension lifting property with respect to all cofibrations. The dual statement holds for maps between cofibrant objects.

G. Rotundo, M. Ausloos

Among topics of opinion formation it is of interest to observe the characteristics of networks with a priori distinct communities. As an illustration, we report on the citation network(s) unfolded in the recent decades through web available works belonging to selected members of the Neocreationist and Intelligent Design Proponents (IDP) and the Darwinian Evo

Richard J. Allison, Simon P. Goodwin, Richard J. Parker, Simon F. Portegies Zwart

Observations and theory both suggest that star clusters form sub-virial (cool) with highly sub-structured distributions. We perform a large ensemble of N-body simulations of moderate-sized (N=1000) cool, fractal clusters to investigate their early dynamical evolution. We find that cool, clumpy clusters dynamically mass segregate on a short timescale, that Tr

P. J. van Zwol, G. Palasantzas

In order to explore repulsive Casimir/van der Waals forces between solid materials with liquid as the intervening medium, we analyze dielectric data for a wide range of materials as for example PTFE, polystyrene, silica and more than twenty liquids. Although significant variation in the dielectric data from different sources exist, we provide a scheme based

A. Fix, V. L. Kashevarov, A. Lee, M. Ostrick

Photoproduction of pi0-eta on protons in the energy range from threshold to 1.4 GeV is discussed. The data for representative angular distributions recently obtained at MAMI C are analyzed using an isobar model. The isobars considered are Delta(1232) and S11(1535) for pi0-p and eta-p states, respectively. In accordance with the results of earlier works the m

Lucio Bedulli, Anna Gori, Fabio Podestà

We prove that any invariant hypercomplex structure on a homogeneous space $M = G/L$ where $G$ is a compact Lie group is obtained via the Joyce's construction, provided that there exists a hyper-Hermitian naturally reductive invariant metric on $M$.

S. Jukna, G. Schnitger

We consider boolean circuits computing n-operators f:{0,1}^n --> {0,1}^n. As gates we allow arbitrary boolean functions; neither fanin nor fanout of gates is restricted. An operator is linear if it computes n linear forms, that is, computes a matrix-vector product y=Ax over GF(2). We prove the existence of n-operators requiring about n^2 wires in any circuit

S. Caenepeel

We associate two linear categories with two objects to a module over the subalgebra of coinvariants of a Hopf-Galois extension, and prove that they are isomorphic. The structure Theorem for cleft extensions, and the Militaru \cStefan lifting Theorem can be obtained using these isomorphisms.

Thomas Henning, Harald Mutschke

Nanometer- and micrometer-sized solid particles play an important role in the evolutionary cycle of stars and interstellar matter. The optical properties of cosmic grains determine the interaction of the radiation field with the solids, thereby regulating the temperature structure and spectral appearance of dusty regions. Radiation pressure on dust grains an

Lucie Baudouin, Julien Salomon, Gabriel Turinici

The goal of this paper is to provide an analysis of the "toolkit" method used in the numerical approximation of the time-dependent Schrödinger equation. The "toolkit" method is based on precomputation of elementary propagators and was seen to be very efficient in the optimal control framework. Our analysis shows that this method provides bett

Philippe Ghendrih, Maxime Hauray, Anne Nouri

A finite Larmor radius approximation is derived from the classical Vlasov equation, in the limit of large (and uniform) external magnetic field. We also provide an heuristic derivation of the electroneutrality equation in the finite Larmor radius setting. Existence and uniqueness of a solution is proven in the stationary frame for solutions depending only on

G. Palla, L. Lovasz, T. Vicsek

We introduce a new approach to constructing networks with realistic features. Our method, in spite of its conceptual simplicity (it has only two parameters) is capable of generating a wide variety of network types with prescribed statistical properties, e.g., with degree- or clustering coefficient distributions of various, very different forms. In turn, thes

Philippe Jouan

It is first shown that a smooth controllable system on a compact manifold is finite time controllable. The technique of proof is close to the one of Sussmann's orbit theorem, and no rank condition is required. This technique is also used to give a new and elementary proof of the equivalence between controllability for essentially bounded inputs and for p

Azzouz Zinoun, Dominique Kazmierowski, Ahmed Intissar

The Landau operator on the quaternionic field is defined as the partial Fourier transform of the sub-Laplacian on the quaternionic Heisenberg group. This operator is viewed as the Hamiltonian of two harmonic oscillators on the two dimensional complex space with a uniform magnetic field.

Robert Oates, Julie Greensmith, Uwe Aickelin, Jonathan M. Garibaldi

The dendritic cell algorithm is an immune-inspired technique for processing time-dependant data. Here we propose it as a possible solution for a robotic classification problem. The dendritic cell algorithm is implemented on a real robot and an investigation is performed into the effects of varying the migration threshold median for the cell population. The a

Dae-Woong Lee

Let $[ρ_{i_k},[ρ_{i_{k-1}},...,[ρ_{i_{1}}, ρ_{i_2}] ...]]$ be an iterated commutator of self-maps $ρ_{i_j} : Σ{\Bbb H}P^\infty \to Σ{\Bbb H}P^\infty, j = 1,2, ..., k$ on the suspension of the infinite quaternionic projective space. In this paper, it is shown that the image of the homomorphism induced by the adjoint of this commutator is both primitive and de

Mathieu Cunche, Valentin Savin, Vincent Roca

In this paper, we show that Quasi-Cyclic LDPC codes can efficiently accommodate the hybrid iterative/ML decoding over the binary erasure channel. We demonstrate that the quasi-cyclic structure of the parity-check matrix can be advantageously used in order to significantly reduce the complexity of the ML decoding. This is achieved by a simple row/column permu

Grazziela P. Figueredo, Uwe Aickelin, Amanda Whitbrook

The study of immune system aging, i.e. immunosenescence, is a relatively new research topic. It deals with understanding the processes of immunodegradation that indicate signs of functionality loss possibly leading to death. Even though it is not possible to prevent immunosenescence, there is great benefit in comprehending its causes, which may help to rever

Valentin Savin

We propose a new code design that aims to distribute an LDPC code over a relay channel. It is based on a split-and-extend approach, which allows the relay to split the set of bits connected to some parity-check of the LDPC code into two or several subsets. Subsequently, the sums of bits within each subset are used in a repeat-accumulate manner in order to ge

Ricardo Caroca, Nelson Merino, Patricio Salgado

By means of a generalization of the S-expansion method we construct a procedure to obtain expanded higher-order Lie algebras. It is shown that the direct product between an Abelian semigroup S and a higher-order Lie algebra ($\mathcal{G},[,...,])$ is also a higher-order Lie algebra. From this S-expanded Lie algebra are obtained resonant submultialgebras and

Asghar Rahimi, Peter Balazs

Multipliers have been recently introduced as operators for Bessel sequences and frames in Hilbert spaces. These operators are defined by a fixed multiplication pattern (the symbol) which is inserted between the analysis and synthesis operators. In this paper, we will generalize the concept of Bessel multipliers for p-Bessel and p-Riesz sequences in Banach sp

Enore Guadagnini, Francesco Mancarella

We consider the link invariants defined by the quantum Chern-Simons field theory with compact gauge group U(1) in a closed oriented 3-manifold M. The relation of the abelian link invariants with the homology group of the complement of the links is discussed. We prove that, when M is a homology sphere or when a link -in a generic manifold M- is homologically

Xiaohua Wu, Fei Wu

Following the work of Niu and Griffiths, in \emph{Phys.Rev.A 58, 4377(1998)}, we shall investigate the problem, how to design the optimal quantum cloning machines (QCMs) for qubit system, with the help of Bloch-sphere representation. In stead of the quality factor there, the Fiuráusek's optimal condition, where the optimal cloning machine should maximize

Gábor Balló, Katalin M. Hangos

A convex optimization based method is proposed for quantum process tomography, in the case of known channel model structure, but unknown channel parameters. The main idea is to select an affine parametrization of the Choi matrix as a set of optimization variables, and formulate a semidefinite programming problem with a least squares objective function. Possi

Loic Foissy, Jeremie Unterberger

We construct an explicit Hopf algebra isomorphism from the algebra of heap-ordered trees to that of quasi-symmetric functions, generated by formal permutations, which is a lift of the natural projection of the Connes-Kreimer algebra of decorated rooted trees onto the shuffle algebra. This isomorphism gives a universal way of lifting measure-indexed character

A. A. Aligia, T. Kroll

We describe a simple scheme to construct a low-energy effective Hamiltonian H_eff for highly correlated systems containing non-metals like O, P or As (O in what follows) and a transition-metal (M) as the active part in the electronic structure, eliminating the O degrees of freedom from a starting Hamiltonian that contains all M d orbitals and all non-metal p

R. Hambach, C. Giorgetti, N. Hiraoka, Y. Q. Cai

The electron energy-loss function of graphite is studied for momentum transfers q beyond the first Brillouin zone. We find that near Bragg reflections the spectra can change drastically for very small variations in q. The effect is investigated by means of first principle calculations in the random phase approximation and confirmed by inelastic x-ray scatter

D. Yu. Tsvetkov, P. Balanutsa, E. S. Gorbovskoy, D. A. Kuvshinov

CCD BVRI photometry is presented for type Ia supernova 2008gy. The light curves match the template curves for fast-declining SN Ia, but the colors appear redder than average, and the SN may also be slightly subluminous. SN 2008gy is found to be located far outside the boundaries of three nearest galaxies, each of them has nearly equal probability to be the h

C. Y. Ryu, C. H. Hyun, S. W. Hong

We investigate the properties of an antikaon in medium, regarding itas a MIT bag. We first construct the MIT bag model for a kaon with$σ^*$ and $ϕ$ in order to describe the interaction of$s$-quarks in hyperonic matter in the framework of the modifiedquark-meson coupling model. The coupling constant $g'^{B_K}_σ$in the density-dependent bag constant $B(σ)$

Natalia Silberstein, Tuvi Etzion

In this paper we consider the existence of nontrivial perfect codes in the Johnson graph J(n,w). We present combinatorial and number theory techniques to provide necessary conditions for existence of such codes and reduce the range of parameters in which 1-perfect and 2-perfect codes may exist.

Daniil Ryabko

The problem of clustering is considered, for the case when each data point is a sample generated by a stationary ergodic process. We propose a very natural asymptotic notion of consistency, and show that simple consistent algorithms exist, under most general non-parametric assumptions. The notion of consistency is as follows: two samples should be put into t

Hena Das, Nicola A. Spaldin, Umesh V. Waghmare, T. Saha-Dasgupta

Using first-principles density functional calculations, we study the interplay of ferroelectricity and polar discontinuities in a range of 1-1 oxide superlattices, built out of ferroelectric and paraelectric components. Studies have been carried out for a varied choice of chemical composition of the components. We find that, when polar interfaces are present

Neri Merhav

We derive a simple general parametric representation of the rate-distortion function of a memoryless source, where both the rate and the distortion are given by integrals whose integrands include the minimum mean square error (MMSE) of the distortion $Δ=d(X,Y)$ based on the source symbol $X$, with respect to a certain joint distribution of these two random v

Hakan Ciftci

In this short note, we have defined a new "nested square root" function which generates usual Pi number for $x=2$. We have given some useful identities and asymptotic formulas of the Pi-function.

Raul E. Curto, Sang Hoon Lee, Jasang Yoon

We study the Subnormal Completion Problem (SCP) for 2-variable weighted shifts. We use tools and techniques from the theory of truncated moment problems to give a general strategy to solve SCP. We then show that when all quadratic moments are known (equivalently, when the initial segment of weights consists of five independent data points), the natural neces

Ilya Safro, Boris Temkin

We present a fast multiscale approach for the network minimum logarithmic arrangement problem. This type of arrangement plays an important role in a network compression and fast node/link access operations. The algorithm is of linear complexity and exhibits good scalability which makes it practical and attractive for using on large-scale instances. Its effec

Radoslav Kirov, Ramin Naimi

In 1990, Kostochka and Sidorenko proposed studying the smallest number of list-colorings of a graph $G$ among all assignments of lists of a given size $n$ to its vertices. We say a graph $G$ is $n$-monophilic if this number is minimized when identical $n$-color lists are assigned to all vertices of $G$. Kostochka and Sidorenko observed that all chordal graph

J. Teyssier, E. Giannini, V. Guritanu, R. Viennois

We report the discovery of a new spin glass ground state in the transition metal monosilicides with the B20 crystallographic structure. Magnetic, transport, neutron and muon investigation of the solid solution Mn$_{1-x}$Co$_{x}$Si have revealed a new dome in the phase diagram with evidence of antiferromagnetic interactions. For Mn rich compounds, a sharp dec

Jaewon Kim, Jonghyun Park

In this paper, the required amount of feedback overhead for multiple-input multiple-output (MIMO) beamforming over time-varying channels is presented in terms of the entropy of the feedback messages. In the case that each transmit antenna has its own power amplifier which has individual power limit, it has been known that only phase steering information is n

Lucio Marassi

Several independent cosmological tests have shown evidences that the energy density of the Universe is dominated by a dark energy component, which cause the present accelerated expansion. The large scale structure formation can be used to probe dark energy models, and the mass function of dark matter haloes is one of the best statistical tools to perform thi

Deepak K. Singh, T. Yang, Mark T. Tuominen

Arrays of nanoscopic magnetic asymmetric rings, 150 nm in outer diameter, are fabricated using the techniques of electron-beam lithography, angular deposition and ion-beam etching. Magnetic measurements for cobalt asymmetric rings at room temperature verifies previous reports of vortex magnetic state formation of a desired circulation direction for the appli

Staša Milojević

The goal of the study is to determine the underlying processes leading to the observed collaborator distribution in modern scientific fields, with special attention to non-power law behavior. Nanoscience is used as a case study of a modern interdisciplinary field, and its coauthorship network for 2000-04 period is constructed from NanoBank database. We find

Zhi-Qing Zhang

In this paper, we calculate the branching ratios and CP-violating asymmetries for \bar B^0_s \to f_0(980)K, f_0(1500)K within Perturbative QCD approach based on k_T factorization. If the mixing angle $θ$ falls into the range of 25^\circ<θ<40^\circ, the branching ratio of \bar B^0_s\to f_0(980)K is 2.0\times 10^{-6}<{\cal B}(\bar B^0_s\to f_0(980)K)<2.6\times

Takuma Matsumoto, Reizaburo Kitai

We have derived the temporal power spectra of the horizontal velocity of the solar photosphere. The data sets for 14 quiet regions observed with the Gband filter of Hinode/SOT are analyzed to measure the temporal fluctuation of the horizontal velocity by using the local correlation tracking (LCT) method. Among the high resolution (~0.2&#34;) and seeing-free

C. Weeks, M. Franz

Electrons hopping on the sites of a two-dimensional Lieb lattice and three-dimensional edge centered cubic (perovskite) lattice are shown to form topologically non-trivial insulating phases when spin-orbit coupling is introduced. These simple models on lattices with cubic symmetry show a Dirac-like structure in the excitation spectrum but with the unusual fe

Sheng Chen, Maohai Huang

We analyze large scale mapping observations of the molecular lines in the 12CO (J=2-1), 12CO (J=3-2), 13CO (J=2-1), and 13CO (J=3-2) transition emissions toward the Cepheus B molecular cloud with the KOSMA 3m-telescope. The integrated intensity map of the 12CO (J=2-1) transition has shown a structure with a compact core and a compact ridge extended in the no

Andrey Sokolov, Andrew Melatos, Tien Kieu

We analyze a simple asset transfer model in which the transfer amount is a fixed fraction $f$ of the giver&#39;s wealth. The model is analyzed in a new way by Laplace transforming the master equation, solving it analytically and numerically for the steady-state distribution, and exploring the solutions for various values of $f\in(0,1)$. The Laplace transform

Gordon V. Cormack, Mark D. Smucker, Charles L. A. Clarke

The TREC 2009 web ad hoc and relevance feedback tasks used a new document collection, the ClueWeb09 dataset, which was crawled from the general Web in early 2009. This dataset contains 1 billion web pages, a substantial fraction of which are spam --- pages designed to deceive search engines so as to deliver an unwanted payload. We examine the effect of spam

Ali E. Pusane, Roxana Smarandache, Pascal O. Vontobel, Daniel J. Costello

Low-density parity-check (LDPC) convolutional codes are capable of achieving excellent performance with low encoding and decoding complexity. In this paper we discuss several graph-cover-based methods for deriving families of time-invariant and time-varying LDPC convolutional codes from LDPC block codes and show how earlier proposed LDPC convolutional code c

Dmitry Savransky, N. Jeremy Kasdin

We present a vector formulation of an interferometric observation of a star, including the effects of the barycentric motion of the observatory, the proper motions of the star, and the reflex motions of the star due to orbiting planets. We use this model to empirically determine the magnitude and form of the signal due to a single Earth-mass planet orbiting

T. C. Liu, M. A. Huang, Guey-Lin Lin

We discuss the reconstruction of neutrino flavor neutrino at a distant source in the very high en- ergy regime. This reconstruction procedure is relevant to the confirmation of detecting cosmogenic neutrinos, for example. To facilitate such a reconstruction, it is imperative to achieve effective flavor discriminations in terrestrial neutrino telescopes. We n

D. Kalok, A. Bilusic, T. I. Baturina, V. M. Vinokur

We investigate experimentally the electric transport at the insulating side of the superconductor to insulator transition in thin TiN-films. At temperatures T > 50 mK we observe an Arrhenius-type conductance, with an activation energy depending logarithmically on the sample size. At high bias the current voltage (I-V) characteristics display a large current

Hajime Kawahara, Yuka Fujii

Scattered lights from terrestrial exoplanets provide valuable information about the planetary surface. Applying the surface reconstruction method proposed by Fujii et al. (2010) to both diurnal and annual variations of the scattered light, we develop a reconstruction method of land distribution with both longitudinal and latitudinal resolutions. We find that

Alexandre d&#39;Aspremont, Noureddine El Karoui

We study a weaker formulation of the nullspace property which guarantees recovery of sparse signals from linear measurements by l_1 minimization. We require this condition to hold only with high probability, given a distribution on the nullspace of the coding matrix A. Under some assumptions on the distribution of the reconstruction error, we show that testi

Jorge G. Cardoso

A review of some facts concerning classical spacetime geometry is presented together with a description of the most elementary aspects of the two-component spinor formalisms of Infeld and van der Waerden. Special attention is concentrated upon the gauge characterization of the basic geometric objects borne by the formalisms. It is pointed out that spin-affin

F. J. Burnell, Steven H. Simon

Levin and Wen [Phys. Rev. B 71, 045110 (2005)] have recently given a lattice Hamiltonian description of doubled Chern-Simons theories. We relate the partition function of these theories to an expectation of Wilson loops that form a link in 2+1 dimensional spacetime known in the mathematical literature as Chain-Mail. This geometric construction gives physical

Gianluca Calcagni, Giuseppe Nardelli

We propose a nonlocal scalar-tensor model of gravity with pseudodifferential operators inspired by the effective action of p-adic string and string field theory on flat spacetime. An infinite number of derivatives act both on the metric and scalar field sector. The system is localized via the diffusion equation approach and its cosmology is studied. We find

Thomas B. Schrøder, Nicoletta Gnan, Ulf R. Pedersen, Nicholas P. Bailey

This series of papers is devoted to identifying and explaining the properties of strongly correlating liquids, i.e., liquids with more than 90% correlation between their virial W and potential energy U fluctuations in the NVT ensemble. Paper IV [N. Gnan et al., J. Chem. Phys. v131, 234504 (2009)] showed that strongly correlating liquids have &#34;isomorphs&#

N. P. Hathi, R. E. Ryan, S. H. Cohen, H. Yan

We combine new high sensitivity ultraviolet (UV) imaging from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) with existing deep HST/Advanced Camera for Surveys (ACS) optical images from the Great Observatories Origins Deep Survey (GOODS) program to identify UV-dropouts, which are Lyman break galaxy (LBG) candidates at z~1-3. These new HST

Nathan Berkovits, Luca Mazzucato

In the pure spinor formalism for the superstring, the b antighost is necessary for multiloop amplitude computations and is a composite operator constructed to satisfy {Q,b}=T where Q is the BRST operator and T is the holomorphic stress-tensor. In superstring backgrounds with only NS-NS fields turned on, or in flat space, one needs to introduce &#34;non-minim

Bobby Samir Acharya, Konstantin Bobkov, Piyush Kumar

We give an explicit realization of the &#34;String Axiverse&#34; discussed in Arvanitaki et. al \cite{Arvanitaki:2009fg} by extending our previous results on moduli stabilization in $M$ theory to include axions. We extend the analysis of \cite{Arvanitaki:2009fg} to allow for high scale inflation that leads to a moduli dominated pre-BBN Universe. We demonstra

P. Lunkenheimer, S. Kastner, M. K öhler, A. Loidl

We present the temperature dependence of alpha-relaxation times of 13 glass formers determined from broadband dielectric spectroscopy, also including data from aging measurements. The data sets partly cover relaxation-time ranges of up to 16 decades enabling a critical test of the validity of model predictions. For this purpose, the data are provided for ele

Vlad Gheorghiu, Li Yu, Scott M. Cohen

We investigate the conditions under which a set $\SC$ of pure bipartite quantum states on a $D\times D$ system can be locally cloned deterministically by separable operations, when at least one of the states is full Schmidt rank. We allow for the possibility of cloning using a resource state that is less than maximally entangled. Our results include that: (i

Chee Sheng Fong, M. C. Gonzalez-Garcia, Enrico Nardi, J. Racker

We revisit flavour effects in soft leptogenesis relaxing the assumption of universality for the soft supersymmetry breaking terms. We find that with respect to the case in which the heavy sneutrinos decay with equal rates and equal CP asymmetries for all lepton flavours, hierarchical flavour configurations can enhance the efficiency by more than two orders o

Jacob Linder, Asle Sudbø

Motivated by a recent experiment evidencing triplet superconductivity in a ferromagnetic Josephson junction with a Cu$_2$MnAl-Heusler barrier, we construct a theoretical model accounting for this observation. The key ingredients in our model which generate the triplet supercurrent are \textit{spin-active zones}, characterised by an effective canted interface

Paul Buterus, Friedrich Götze, Thomas Hille, Gregory Margulis

The number of lattice points in $d$-dimensional hyperbolic or elliptic shells $\{m : a<Q[m]<b\}$, which are restricted to rescaled and growing domains $r\;\Omega$, is approximated by the volume. An effective error bound of order $o(r^{d-2})$ for this approximation is proved based on Diophantine approximation properties of the quadratic form $Q$. These result

Hidetoshi Awata, Yasuhiko Yamada

We discuss an analog of the AGT relation in five dimensions. We define a q-deformation of the beta-ensemble which satisfies q-W constraint. We also show a relation with the Nekrasov partition function of 5D SU(N) gauge theory with N_f=2N.

N. Madhusudhan, S. Seager

We present a detailed analysis of the dayside atmosphere of the hot-Neptune GJ~436b, based on recent Spitzer observations. We report statistical constraints on the thermal and chemical properties of the planetary atmosphere, study correlations between the various molecular species, and discuss scenarios of equilibrium and non-equilibrium chemistry in GJ 436b

David Ben-Zvi, David Nadler

We introduce loop spaces (in the sense of derived algebraic geometry) into the representation theory of reductive groups. In particular, we apply the theory developed in our previous paper arXiv:1002.3636 to flag varieties, and obtain new insights into fundamental categories in representation theory. First, we show that one can recover finite Hecke categorie

Andrea Gabrielli, Michael Joyce, Bruno Marcos

&#34;Quasi-stationary&#34; states are approximately time-independent out of equilibrium states which have been observed in a variety of systems of particles interacting by long-range interactions. We investigate here the conditions of their occurrence for a generic pair interaction V(r \rightarrow \infty) \sim 1/r^a with a > 0, in d>1 dimensions. We generali

Juha Javanainen, Otim Odong, Jerome C. Sanders

We investigate theoretically the stationary states of two bosons in a one-dimensional optical lattice within the Bose-Hubbard model. Starting from a finite lattice with periodic boundary conditions, we effect a partial separation of the center-of-mass and relative motions of the two-atom lattice dimer in the lattice momentum representation, and carefully ana

Oleg A. Starykh, Hosho Katsura, Leon Balents

We report a thorough theoretical study of the low temperature phase diagram of Cs_2CuCl_4, a spatially anisotropic spin S=1/2 triangular lattice antiferromagnet, in a magnetic field. Our results, obtained in a quasi-one-dimensional limit in which the system is regarded as a set of weakly coupled Heisenberg chains, are in excellent agreement with experiment.

Michele Redi, Ben Gripaios

We study the idea of the Higgs as a pseudo-Goldstone boson within the framework of partial supersymmetry in Randall-Sundrum scenarios and their CFT duals. The Higgs and third generation of the MSSM are composites arising from a strongly coupled supersymmetric CFT with global symmetry SO(5) spontaneously broken to SO(4), whilst the light generations and gauge

Rathin Adhikari, Amitava Raychaudhuri

We present general conditions on Dirac and Majorana mass terms under which a type-I seesaw mechanism can lead to three exactly massless neutrinos at the tree level. We depict several examples where the conditions are satisfied and relate some of them to an underlying U(1) symmetry. We show that higher order corrections may generate the small observed masses