February 2010 arXiv papers — page 11

Saif Khan Mohammed, Emanuele Viterbo, Yi Hong, Ananthanarayanan Chockalingam

We consider Gaussian multiple-input multiple-output (MIMO) channels with discrete input alphabets. We propose a non-diagonal precoder based on the X-Codes in \cite{Xcodes_paper} to increase the mutual information. The MIMO channel is transformed into a set of parallel subchannels using Singular Value Decomposition (SVD) and X-Codes are then used to pair the

Robert Stelzer

Multivariate $\operatorname {COGARCH}(1,1)$ processes are introduced as a continuous-time models for multidimensional heteroskedastic observations. Our model is driven by a single multivariate Lévy process and the latent time-varying covariance matrix is directly specified as a stochastic process in the positive semidefinite matrices. After defining the $\op

Markku Nihtilä

In the design of quantum computing devices of the future the basic element is the qubit. It is a two-level quantum system which may describe population transfer from one steady-state to another controlled by a coherent laser field. A four-dimensional real-variable differential equation model is constructed from the complex-valued two-level model describing t

V. S. Rabinovich, S. Roch

Let $Γ$ be a finitely generated discrete exact group. We consider operators on $l^2(Γ)$ which are composed by operators of multiplication by a function in $l^\infty (Γ)$ and by the operators of left-shift by elements of $Γ$. These operators generate a $C^*$-subalgebra of $L(l^2(Γ))$ the elements of which we call band-dominated operators on $Γ$. We study the

Vicky Fasen

We consider a positive stationary generalized Ornstein--Uhlenbeck process \[V_t=\mathrm{e}^{-ξ_t}\biggl(\int_0^t\mathrm{e}^{ξ_{s-}}\ ,\mathrm{d}η_s+V_0\biggr)\qquadfor t\geq0,\] and the increments of the integrated generalized Ornstein--Uhlenbeck process $I_k=\int_{k-1}^k\sqrt{V_{t-}} \mathrm{d}L_t$, $k\in\mathbb{N}$, where $(ξ_t,η_t,L_t)_{t\geq0}$ is a thre

T. K. Jha, H. Mishra, V. Sreekanth

We consider a rotating neutron star with the presence of hyperons in its core, using an equation of state in an effective chiral model within the relativistic mean field approximation. We calculate the hyperonic bulk viscosity coefficient due to nonleptonic weak interactions. By estimating the damping timescales of the dissipative processes, we investigate i

Julien Langou

A QR factorization of a tall and skinny matrix with n columns can be represented as a reduction. The operation used along the reduction tree has in input two n-by-n upper triangular matrices and in output an n-by-n upper triangular matrix which is defined as the R factor of the two input matrices stacked the one on top of the other. This operation is binary,

Ganquan Xie, Jianhua Li, Lee Xie, Feng Xie

In this paper, we propose a novel GLWF double layer EM cloak in the broad frequency band. The GLWF double layer cloak consists of two sphere annular layers, two type cloak materials are proposed and installed in its each layer, respectively. The outer layer of the GL cloak has the invisible function in broad frequency band, while its inner layer has the full

Jun Ohkubo, Thomas Eggel

We propose a direct numerical method to calculate the statistics of the number of transitions in stochastic processes, without having to resort to Monte Carlo calculations. The method is based on a generating function method, and arbitrary moments of the probability distribution of the number of transitions are in principle calculated by solving numerically

Rohta Takahashi, Masaaki Takahashi

Aims. In order to understand the anisotropic properties of local radiation field in the curved spacetime around a rotating black hole, we investigate the appearance of a black hole seen by an observer located near the black hole. When the black hole is in front of a source of illumination the black hole cast shadow in the illumination. Accordingly, the appea

Fabrizio Massi, Elisa Di Carlo, Claudio Codella, Leonardo Testi

Context. The Vela Molecular Ridge hosts a number of young embedded star clusters in the same evolutionary stage. Aims. The main aim of the present work is testing whether the fraction of members with a circumstellar disk in a sample of clusters in the cloud D of the Vela Molecular Ridge, is consistent with relations derived for larger samples of star cluster

E. Agudelo, B. A. Rodriguez, K. M. Fonseca-Romero

We propose an experimental setup, feasible with present day technology, involving two highquality- factor cavities, one Ramsey zone and a two-level atom which interacts with them. The dynamics in the cavities is modeled by a dissipative dispersive Jaynes-Cummings model. Analytical expresions for the evolution superoperator in each part of the proposed setup

Anton Kapustin, Ketan Vyas

We introduce and study a new 3d Topological Field Theory which can be associated to any compact real manifold X. This TFT is analogous to the 2d A-model and reduces to it upon compactification on an interval with suitable boundary conditions. It plays a role in 3d mirror symmetry as well as in the physical approach to the geometric Langlands duality. A simil

Yang Liu, Karin A. Dahmen

We find that some equilibrium systems and their non-equilibrium counterparts actually show the same jerky response or avalanche behavior on many scales in response to slowly changing external conditions. In other words, their static and dynamic avalanches behave statistically the same. This suggests that their critical properties are much more generally appl

M. A. Maize, M. A. Antonacci

In this paper we derive an expression for the static electric polarizability of a particle bound by a finite potential well without the explicit use of the continuum states in our calculations. This will be accomplished by employing the elegant Dalgarno-Lewis perturbative technique.

Holger Mueller, Jian Jin, Radostin Danev, John Spence

We propose a Zernike phase contrast electron microscope that uses an intense laser focus to convert a phase image into a visible image. We present the relativistic quantum theory of the phase shift caused by the laser-electron-interaction, study resonant cavities for enhancing the laser intensity, and discuss applications in biology, soft materials science,

Beate West, Friederike Schmid

We study the stress distribution profiles and the height and thickness fluctuations of lipid membranes in the tilted gel state by Monte Carlo simulations of a generic coarse-grained model for lipid membranes, which reproduces many known properties of DPPC bilayers. The results are related to the corresponding properties of fluid membranes, and to theoretical

Hiroyuki Osaka, Tamotsu Teruya

Let $P \subset A$ be a inclusion of unital C*-algebras and $E\colon A \to P$ be a conditional expectation of index finite type. We introduce a Rokhlin property for $E$ and discuss about $\mathcal{D}$-absorbing proeprty, where $\mathcal{D}$ is a separable, unital, strongly self-absorbing C*-algebra. In this paper we consider permanent properties for strongly

Bo Wang, Zhengwei Liu, Yunkun Han, Zhenxin Lei

Type Ia supernovae (SNe Ia) play an important role in diverse areas of astrophysics, from the chemical evolution of galaxies to observational cosmology. However, the nature of the progenitors of SNe Ia is still unclear. In this paper, according to a detailed binary population synthesis study, we obtained SN Ia birthrates and delay times from different progen

David Collins

We describe a general framework for regarding oracle-assisted quantum algorithms as tools for discriminating between unitary transformations. We apply this to the Deutsch-Jozsa problem and derive all possible quantum algorithms which solve the problem with certainty using oracle unitaries in a particular form. We also use this to show that any quantum algori

Michael Carley

A method for moving least squares interpolation and differentiation is presented in the framework of orthogonal polynomials on discrete points. This yields a robust and efficient method which can avoid singularities and breakdowns in the moving least squares method caused by particular configurations of nodes in the system. The method is tested by applying i

Stanley P. Gudder

An anhomomorphic logic $\ascript ^*$ is the set of all possible realities for a quantum system. Our main goal is to find the "actual reality" $ϕ_a\in\ascript ^*$ for the system. Reality filters are employed to eliminate unwanted potential realities until only $ϕ_a$ remains. In this paper, we consider three reality filters that are constructed by mean

L. Borsten, D. Dahanayake, M. J. Duff, S. Ferrara

One would often like to know when two a priori distinct extremal black p-brane solutions are in fact U-duality related. In the classical supergravity limit the answer for a large class of theories has been known for some time. However, in the full quantum theory the U-duality group is broken to a discrete subgroup and the question of U-duality orbits in this

Varun K. A. S., Yekaterina A. Ivukina, Wei Deng, Timothy A. Kelf

This is a new nanoparticle bioconjugation reaction.

S. Molchanov, B. Vainberg

The Anderson Hamiltonian $H_0=-Δ+V(x,ω)$ is considered, where $V$ is a random potential of Bernoulli type. The operator $H_0$ is perturbed by a non-random, continuous potential $-w(x) \leq 0$, decaying at infinity. It will be shown that the borderline between finitely, and infinitely many negative eigenvalues of the perturbed operator, is achieved with a dec

Sofia Wechsler

A single-particle multi-branched wave-function is studied. Usual which-path tests show that if the detector placed on one branch clicks, the detectors on the other branches remain silent. By the collapse postulate, after this click, the state of the particle is reduced to a single branch, the branch on which the detector clicked. The present article challeng

Y. H. Ahn, Chuan-Hung Chen

A new scheme for Yukawa matrices is proposed for free of flavor changing neutral currents (FCNCs) at tree level in general two-Higgs-doublet model (THDM) without imposing symmetry. We find that the new type couplings of charged Higgs to fermions not only depend on the flavors, but also can be ascribed by new CP violating phases. Unlike conventional THDM, the

Panagiotis Cheilaris, Balázs Keszegh, Dömötör Pálvölgyi

We investigate the relationship between two kinds of vertex colorings of hypergraphs: unique-maximum colorings and conflict-free colorings. In a unique-maximum coloring, the colors are ordered, and in every hyperedge of the hypergraph the maximum color appears only once. In a conflict-free coloring, in every hyperedge of the hypergraph there is a color that

Rodolfo Gambini, Luis Pedro Garcia-Pintos, Jorge Pullin

We make a first attempt to axiomatically formulate the Montevideo interpretation of quantum mechanics. In this interpretation environmental decoherence is supplemented with loss of coherence due to the use of realistic clocks to measure time to solve the measurement problem. The resulting formulation is framed entirely in terms of quantum objects without hav

Yossi Cohen, Itamar Procaccia

Motivated by recent experiments, we present a study of the dynamics of cracks in thin sheets. While the equations of elasticity for thin plates are well known, there remains the question of path selection for a propagating crack. We invoke a generalization of the principle of local symmetry to provide a criterion for path selection and demonstrate qualitativ

N. P. Armitage, Riccardo Tediosi, F. Levy, E. Giannini

The application of pressure to elemental bismuth reduces its conduction-valence band overlap, and results in a semimetal-semiconductor (SMSC) transition around 25 kbar. This transition is nominally of the topological "Lifshitz" Fermi surface variety, but there are open questions about the role of interactions at low charge densities. Using a novel pr

P. Parisi, N. Masetti

Thanks to the INTEGRAL satellite the way of looking at the hard X-ray sky above 20 keV has changed substantially. Through the unique imaging and spectroscopy capabilities of the IBIS instrument that has formed the basis of the INTEGRAL surveys, this satellite has improved the knowledge on hard X-ray sources in terms of sensitivity and positional accuracy. Ma

Isabeau Prémont-Schwarz, Jeff Hnybida

We propose new Lieb-Robinson bounds (bounds on the speed of propagation of information in quantum systems) with an explicit dependence on the interaction strengths of the Hamiltonian. For systems with more than two interactions it is found that the Lieb-Robinson speed is not always algebraic in the interaction strengths. We consider Hamiltonians with any fin

Y. Dubi, R. R. Biswas, A. V. Balatsky

Phase fluctuations in finite thickness layered superconducting films are studied theoretically. The model consists of a set of layers, coupled to each other via a gradient-like term in the phase-only action. It is shown that the effective phase stiffness of the whole system is proportional to its thickness (i.e. the number of individual layers). This result

Emilio Romano-Diaz, Isaac Shlosman, Clayton Heller, Yehuda Hoffman

We compare the substructure evolution in pure dark matter (DM) halos with those in the presence of baryons (PDM and BDM). The prime halos have been analyzed by Romano-Diaz et al (2009). Models have been evolved from identical initial conditions using Constrained Realizations, including star formation and feedback. A comprehensive catalog of subhalos has been

Konstantin Klemm, M. Angeles Serrano, Victor M. Eguiluz, Maxi San Miguel

Identifying key players in collective dynamics remains a challenge in several research fields, from the efficient dissemination of ideas to drug target discovery in biomedical problems. The difficulty lies at several levels: how to single out the role of individual elements in such intermingled systems, or which is the best way to quantify their importance.

Rachel Bean, Matipon Tangmatitham

We present constraints on the cosmic growth history with recent cosmological data, allowing for deviations from Lambda CDM as might arise if cosmic acceleration is due to modifications to GR or inhomogeneous dark energy. We combine measures of the cosmic expansion history, from Type 1a supernovae, baryon acoustic oscillations and the CMB, with constraints on

Stéphane Ilic, Martin Kunz, Andrew R. Liddle, Joshua A. Frieman

Traditionally, inflationary models are analyzed in terms of parameters such as the scalar spectral index ns and the tensor to scalar ratio r, while dark energy models are studied in terms of the equation of state parameter w. Motivated by the fact that both deal with periods of accelerated expansion, we study the evolution of w during inflation, in order to

Seppo Mattila, Peter Lundqvist, Per Groeningsson, Peter Meikle

We present optical spectroscopic data of the inner circumstellar ring around SN 1987A from the Anglo-Australian Telescope (AAT) and the Very Large Telescope (VLT) between ~1400 and ~5000 days post-explosion. We also assembled the available optical and near-infrared line fluxes from the literature between ~300 and ~2000 days. These line light curves were fitt

Elisabetta Bissaldi

We present the analysis of two long Gamma-Ray Bursts, GRB 090323 and GRB 090328, which triggered the Fermi Gamma-Ray Burst Monitor (GBM) and generated an Autonomous Repoint Request to the Fermi Large Area Telescope. The GBM light curves show multi-peaked structures for both events. Here, we present time-integrated and time-resolved burst spectra fitted with

Aday R. Robaina, Eric F. Bell, Arjen van der Wel, Rachel S. Somerville

We explore the rate and impact of galaxy mergers on the massive galaxy population using the amplitude of the two-point correlation function on small scales for M > 5e10 M_sun galaxies from the COSMOS and COMBO-17 surveys. Using a pair fraction derived from the Sloan Digital Sky Survey as a low-redshift benchmark, the large survey area at intermediate redshif

Nirupam Roy, Jayaram N. Chengalur, Prasun Dutta, Somnath Bharadwaj

The angular power spectrum of HI 21 cm opacity fluctuations is a useful statistic for quantifying the observed opacity fluctuations as well as for comparing these with theoretical models. We present here the HI 21 cm opacity fluctuation power spectrum towards the supernova remnant Cas A from interferometric data with spacial resolution of 5" and spectral

Steven T. Flammia, David Gross, Stephen D. Bartlett, Rolando Somma

We describe an algorithm for quantum state tomography that converges in polynomial time to an estimate, together with a rigorous error bound on the fidelity between the estimate and the true state. The result suggests that state tomography on large quantum systems may be much more feasible than the exponential size of state space suggests. In many situations

J. Maziero, H. C. Guzman, L. C. Celeri, M. S. Sarandy

We investigate pairwise quantum correlation as measured by the quantum discord as well as its classical counterpart in the thermodynamic limit of anisotropic XY spin-1/2 chains in a transverse magnetic field for both zero and finite temperatures. Analytical expressions for both classical and quantum correlations are obtained for spin pairs at any distance. I

Tiago Fonseca, Philippe Nadeau

We are interested in the enumeration of Fully Packed Loop configurations on a grid with a given noncrossing matching. By the recently proved Razumov--Stroganov conjecture, these quantities also appear as groundstate components in the Completely Packed Loop model. When considering matchings with p nested arches, these numbers are known to be polynomials in p.

Olindo Zanotti, Luciano Rezzolla, Luca Del Zanna, Carlos Palenzuela

We investigate the dynamics of a circumbinary disc that responds to the loss of mass and to the recoil velocity of the black hole produced by the merger of a binary system of supermassive black holes. We perform the first two-dimensional general relativistic hydrodynamics simulations of \textit{extended} non-Keplerian discs and employ a new technique to cons

Tianjun Li, Dimitri V. Nanopoulos

In Grand Unified Theories (GUTs), the Standard Model (SM) gauge couplings need not be unified at the GUT scale due to the high-dimensional operators. Considering gravity mediated supersymmetry breaking, we study for the first time the generic gauge coupling relations at the GUT scale, and the general gaugino mass relations which are valid from the GUT scale

Víctor González-Aguilera, Alvaro Liendo

In this paper we give an effective criterion as to when a prime number p is the order of an automorphism of a smooth cubic hypersurface of P^{n+1}, for a fixed n > 1. We also provide a computational method to classify all such hypersurfaces that admit an automorphism of prime order p. In particular, we show that p<2^{n+1} and that any such hypersurface admit

M. Sampoorna, J. Trujillo Bueno

The linearly-polarized solar limb spectrum that is produced by scattering processes contains a wealth of information on the physical conditions and magnetic fields of the solar outer atmosphere, but the modeling of many of its strongest spectral lines requires solving an involved non-LTE radiative transfer problem accounting for partial redistribution (PRD)

Ashoke Sen

AdS_2/CFT_1 correspondence predicts that the logarithm of a Z_N twisted index over states carrying a fixed set of charges grows as 1/N times the entropy of the black hole carrying the same set of charges. In this paper we verify this explicitly by calculating the microscopic Z_N twisted index for a class of states in the CHL models. This demonstrates that bl

G. Bernardi, A. G. de Bruyn, G. Harker, M. A. Brentjens

In the coming years a new insight into galaxy formation and the thermal history of the Universe is expected to come from the detection of the highly redshifted cosmological 21 cm line. The cosmological 21 cm line signal is buried under Galactic and extragalactic foregrounds which are likely to be a few orders of magnitude brighter. Strategies and techniques

C. S. Lam

Identical interactions found in the three families of quarks and leptons suggest the presence of a horizontal symmetry. We discuss how such a symmetry can be tested by measuring the decay rates of Higgs into fermion pairs, and the Higgs production cross section. Depending on the details, there is a chance that the decay widths to the bottom-pair and the tau-

M. Gomes, V. G. Kupriyanov, A. J. da Silva

Using the Berezin-Marinov pseudoclassical formulation of spin particle we propose a classical model of spin noncommutativity. In the nonrelativistic case, the Poisson brackets between the coordinates are proportional to the spin angular momentum. The quantization of the model leads to the noncommutativity with mixed spacial and spin degrees of freedom. A mod

H. Azad, M. T. Mustafa

We show that any differential operator of the form $L(y)=\sum_{k=0}^{k=N} a_{k}(x) y^{(k)}$, where $a_k$ is a real polynomial of degree $\leq k$, has all real eigenvalues in the space of polynomials of degree at most n, for all n. The eigenvalues are given by the coefficient of $x^n$ in $L(x^{n})$. If these eigenvalues are distinct, then there is a unique mo

Marek Wolf

We have used the first 2600 nontrivial zeros gamma_l of the Riemann zeta function calculated with 1000 digits accuracy and developed them into the continued fractions. We calculated the geometrical means of the denominators of these continued fractions and for all cases we get values close to the Khinchin's constant, what suggests that gamma_l are irrational

G. Ramalho, M. T. Pena, Franz Gross

The electromagnetic form factors of the Delta baryon are evaluated within the framework of a covariant spectator quark model, where S and D-states are included in the $Δ$ wave function. We predict all the four Delta multipole form factors: the electric charge GE0, the magnetic dipole GM1, the electric quadrupole GE2 and the magnetic octupole GM3. We compare

Claudio Buzzi, Tiago de Carvalho, Paulo Ricardo da Silva

This paper is concerned with closed orbits of non-smooth vector fields on the plane. For a subclass of non-smooth vector fields we provide necessary and sufficient conditions for the existence of canard kind solutions. By means of a regularization we prove that the canard cycles are singular orbits of singular perturbation problems which are limit periodic s

A. P. Heinson

On March 4, 2009, the DZero and CDF collaborations at Fermilab&#39;s Tevatron Collider submitted papers to Physical Review Letters announcing observation of single top quark production. This review paper describes the successful searches carried out independently by the two collaborations, allowing the reader to see the similarities and differences that led

Daniel Victor Tausk

It has been claimed by Halmos in [Comment on the real line, Bull. Amer. Math. Soc., 50 (1944), 877-878] that if G is a Hausdorff locally compact topological abelian group and if the character group of G is torsion free then G is divisible. We prove that such claim is false, by presenting a family of counterexamples. While other counterexamples are known (see

N. S. Hoang

A version of the Dynamical Systems Method for solving ill-posed nonlinear equations with monotone and locally Hölder continuous operators is studied in this paper. A discrepancy principle is proposed and justified under natural and weak assumptions. The only smoothness assumption on $F$ is the local Hölder continuity of order $α>1/2$.

Anatoly Libgober, Mircea Mustata

To r ideals on a germ of smooth variety X one attaches a rational polytope in the r-dimensional Euclidean space (the LCT-polytope) that generalizes the notion of log canonical threshold in the case of one ideal. We study these polytopes, and prove a strong form of the Ascending Chain Condition in this setting: we show that if a sequence P_m of such LCT-polyt

Howard Baer

Supersymmetric grand unified theories based on the gauge group SO(10) are highly motivated. In the simplest models, one expects t-b-τYukawa coupling unification, in addition to gauge, matter and Higgs unification. Yukawa unification only occurs with very special GUT scale boundary conditions, leading to a spectra with ~10 TeV first and second generation scal

Michael I. Cohen, Curt Cutler, Michele Vallisneri

A network of observable, macroscopic cosmic (super-)strings may have formed in the early universe. If so, the cusps that generically develop on cosmic-string loops emit bursts of gravitational radiation that could be detectable by both ground- and space-based gravitational-wave interferometers. Here we report on two versions of a LISA-oriented string-burst s

Marek Karliner, Harry J. Lipkin

We discuss the implications of the suggested interpretation of the recently reported narrow pi N resonance (width \approx 25 MeV at 1680 MeV) as a pentaquark in the same multiplet as the Theta+. We consider a diquark-triquark pentaquark model involving a recoupling of the five quarks into a diquark-triquark system in non-standard color representations. We es

O. Oliveira, P. Bicudo

The interpretation of the Landau gauge lattice gluon propagator as a massive type bosonic propagator is investigated. Three different scenarios are discussed: i) an infrared constant gluon mass; ii) an ultraviolet constant gluon mass; iii) a momentum dependent mass. We find that the infrared data can be associated with a massive propagator up to momenta $\si

Maria Beltran, Dan Hooper, Edward W. Kolb, Zosia A. C. Krusberg

Assuming that dark matter is a weakly interacting massive particle (WIMP) species X produced in the early Universe as a cold thermal relic, we study the collider signal of pp or ppbar -> XXbar + jets and its distinguishability from standard-model background processes associated with jets and missing energy. We assume that the WIMP is the sole particle relate

Mar Jimenez-Sevilla, Luis Sanchez-Gonzalez

Let us consider a Banach space $X$ with the property that every real-valued Lipschitz function $f$ can be uniformly approximated by a Lipschitz, $C^1$-smooth function $g$ with $\Lip(g)\le C \Lip(f)$ (with $C$ depending only on the space $X$). This is the case for a Banach space $X$ bi-Lipschitz homeomorphic to a subset of $c_0(Γ)$, for some set $Γ$, such tha

Tamerlan Saidov, Alexander Zhuk

We study a gravitational model with curvature-squared $R^2$ and curvature-quartic $R^4$ nonlinearities. The effective scalar degree of freedom $ϕ$ (scalaron) has a multi-valued potential $U(ϕ)$ consisting of a number of branches. These branches are fitted with each other in the branching and monotonic points. In the case of four-dimensional space-time, we sh

Janos Balog, Arpad Hegedus

Using the linearized TBA equations recently obtained in [arXiv:1002.1711] we show analytically that the 5-loop anomalous dimension of the Konishi operator agrees with the result obtained previously from the generalized Luscher formulae. The proof is based on the relation between this linear system and the XXX model TBA equations.

Bijan Sahamie

We show a connection between a surgery exact sequence in knot Floer homology and the sequence derived in [18]. As a consequence of this relationship we see that the exact sequence in [18] also works with coherent orientations and admits refinements with respect to spinc-structures. As an application of this discussion, we prove that the ranks of the image an

P. -G. Reinhard, W. Nazarewicz

We address two questions pertaining to the uniqueness and usefulness of a new observable: (i) Considering the current theoretical knowledge, what novel information does new measurement bring in? (ii) How can new data reduce uncertainties of current theoretical models? We illustrate these points by studying the radius of the neutron distribution of a heavy nu

Chen Lizhu, Yunyun Chen, Wu Yuanfang

It is pointed out that finite-size effect is not negligible in locating critical point of QCD phase transition at current relativistic heavy ion collisions. Finite-size behavior near critical point, in particular, finite-size scaling and fixed-point behavior of the final observables can be served as a quantitative identification of critical point and the nea

Yann Jullian

This article introduces tree substitutions as a tool to give explicit geometric representations of the dynamical systems generated by a particular set of automorphisms of the free group.

R. Aloisio, D. Boncioli

The recent results of the Pierre Auger Observatory on the possible correlation of Ultra High Energy Cosmic Rays events and several nearby discrete sources could be the starting point of a new era with charged particles astronomy. In this paper we introduce a simple model to determine the effects of any local distribution of sources on the expected flux. We c

Vladimir Turaev

We introduce and study knotoids. Knotoids are represented by diagrams in a surface which differ from the usual knot diagrams in that the underlying curve is a segment rather than a circle. Knotoid diagrams are considered up to Reidemeister moves applied away from the endpoints of the underlying segment. We show that knotoids in $S^2$ generalize knots in $S^3

Anthony Leverrier, Philippe Grangier

In this paper, we consider continuous-variable quantum key distribution with a discrete modulation, either binary or quaternary. We establish the security of these protocols against the class of collective attacks that induce a linear quantum channel. In particular, all Gaussian attacks are taken into account, as well as linear attacks which add a non-Gaussi

Claire Amiot, Osamu Iyama, Idun Reiten, Gordana Todorov

Let $Q$ be an acyclic quiver and $Λ$ be the complete preprojective algebra of $Q$ over an algebraically closed field $k$. To any element $w$ in the Coxeter group of $Q$, Buan, Iyama, Reiten and Scott have introduced and studied in \cite{Bua2} a finite dimensional algebra $Λ_w=Λ/I_w$. In this paper we look at filtrations of $Λ_w$ associated to any reduced exp

Andreas Philipp

The investigation and classification of non-unique factorization phenomena have attracted some interest in recent literature. For finitely generated monoids, S.T. Chapman and P. Garcia-Sanchez, together with several co-authors, derived a method to calculate the catenary and tame degree from the monoid of relations, and they applied this method successfully i

Daniel Carando, Daniel Galicer

In the spirit of the work of Grothendieck, we introduce and study natural symmetric n-fold tensor norms. We prove that there are exactly six natural symmetric tensor norms for $n\ge 3$, a noteworthy difference with the 2-fold case in which there are four. We also describe the polynomial ideals associated to these natural symmetric tensor norms. Using a symme

Hung Bui, Brian Conrey, Matthew Young

We prove that more than 41% of the zeros of the zeta function are on the critical line.

Sergiy Zhuk

This paper describes a state estimation approach for non-causal time-varying linear descriptor equations with uncertain parameters. The uncertainty in the state equation and in the measurements is supposed to admit a set-membership description. The approach is based on the notion of the linear minimax estimation. Suboptimal minimax state estimation algorithm

A. Arcones, G. Martinez-Pinedo, L. F. Roberts, S. E. Woosley

The electron-to-nucleon ratio or electron fraction is a key parameter in many astrophysical studies. Its value is determined by weak-interaction rates that are based on theoretical calculations subject to several nuclear physics uncertainties. Consequently, it is important to have a model independent way of constraining the electron fraction value in differe

Claudio Bonati, Adriano Di Giacomo, Luca Lepori, Fabrizio Pucci

A direct connection is proved between the Non-Abelian Bianchi Identities(NABI), and the abelian Bianchi identities for the &#39;t Hooft tensor. As a consequence the existence of a non-zero magnetic current is related to the violation of the NABI&#39;s and is a gauge-invariant property. The construction allows to show that not all abelian projections can be u

Simone Casolo, Espen Flage-Larsen, Ole Martin Løvvik, George R. Darling

Adsorption of gaseous species, and in particular of hydrogen atoms, on graphene is an important process for the chemistry of this material. At the equilibrium geometry, the H atom is covalently bonded to a carbon that puckers out from the surface plane. Nevertheless the \emph{flat} graphene geometry becomes important when considering the full sticking dynami

Dennis Dreesen

Given the Hilbert space compression of two groups, we find bounds on the Hilbert space compression of their free product. We also investigate the Hilbert space compression of an HNN-extension of a group relative to a finite normal subgroup or a finite index subgroup.

Michael P. Tuite, Alexander Zuevsky

We describe the Szeg\"o kernel on a higher genus Riemann surface in terms of Szeg\"o kernel data coming from lower genus surfaces via two explicit sewing procedures where either two Riemann surfaces are sewn together or a handle is sewn to a Riemann surface. We consider in detail the examples of the Szeg\"o kernel on a genus two Riemann surface formed by eit

Nicole Kraemer, Masashi Sugiyama

The derivation of statistical properties for Partial Least Squares regression can be a challenging task. The reason is that the construction of latent components from the predictor variables also depends on the response variable. While this typically leads to good performance and interpretable models in practice, it makes the statistical analysis more involv

Laurent Berger

La correspondance de Langlands locale p-adique pour GL_2(Q_p) est une bijection entre certaines representations de dimension 2 de Gal(Q_p^bar/Q_p) et certaines representations de GL_2(Q_p). Cette bijection peut en fait etre construite en utilisant la theorie des (phi,Gamma)-modules et des resultats d&#39;analyse p-adique. On deduit alors des proprietes de ce

Nicolas C. Menicucci, Xian Ma, Timothy C. Ralph

We present a compact experimental design for producing an arbitrarily large optical continuous-variable cluster state using just one single-mode vacuum squeezer and one quantum nondemolition gate. Generating the cluster state and computing with it happen simultaneously: more entangled modes become available as previous modes are measured, thereby making fini

M. Lehn, Y. Namikawa, Ch. Sorger

We classify the nilpotent orbits in a simple Lie algebra for which the restriction of the adjoint quotient map to a Slodowy slice is the universal Poisson deformation of its central fibre. This generalises work of Brieskorn and Slodowy on subregular orbits. In particular, we find in this way new singular symplectic hypersurfaces of dimension 4 and 6.

Subir Sachdev

I begin with a proposed global phase diagram of the cuprate superconductors as a function of carrier concentration, magnetic field, and temperature, and highlight its connection to numerous recent experiments. The phase diagram is then used as a point of departure for a pedagogical review of various quantum phases and phase transitions of insulators, superco

Hirokazu Nishimura

The central object of synthetic differential geometry is microlinear spaces. In our previous paper [Microlinearity in Frolicher spaces -beyond the regnant philosophy of manifolds-, International Journal of Pure and Applied Mathematics, 60 (2010), 15-24] we have emancipated microlinearity from within well-adapted models to Frolicher spaces. Therein we have sh

Ali H. Chamseddine, Viatcheslav Mukhanov

A Higgs mechanism for gravity is presented, where four scalars with global Lorentz symmetry are employed. We show that in the broken symmetry phase a graviton absorbs all scalars and become massive spin 2 particle with five degrees of freedom. The resulting theory is unitary and free of ghosts.

S. Teber, C. Holmqvist, M. Fogelstrom

We study dc-transport and magnetization dynamics in a junction of arbitrary transparency consisting of two spin-singlet superconducting leads connected via a single classical spin precessing at the frequency $Ω$. The presence of the spin in the junction provides different transmission amplitudes for spin-up and spin-down quasiparticles as well as a time-depe

HaengJin Choe

Rough speaking, information theory deals with data transmitted over a channel such as the internet. Modern information theory is generally considered to have been founded in 1948 by Shannon in his seminal paper, &#34;A mathematical theory of communication.&#34; Shannon&#39;s formulation of information theory was an immediate success with communications engin

Nikolay Gromov, Vladimir Kazakov, Zengo Tsuboi

We solve the recently proposed T- and Y-systems (Hirota equation) for the exact spectrum of AdS/CFT in the strong coupling scaling limit for an arbitrary quasiclassical string state. The corresponding T-functions appear to be super-characters of the SU(2,2|4) group in unitary representations with a highest weight, with the classical AdS5xS5 superstring monod

C. Hanhart, Yu. S. Kalashnikova, A. V. Nefediev

We discuss on very general grounds possible lineshapes of composite particles with one unstable constituent. Expressions are derived in a coupled-channel formalism for constituents interacting in an S-wave with no assumption made on the width of one of them. We show how easy-to-use formulae, already existing in the literature, emerge for narrow constituents

G. Lanzafame

In the non viscous fluid dynamics, Smooth Particle Hydrodynamics (SPH), as a free Lagrangian &#34;shock capturing&#34; method adopts either an artificial viscosity contribution or an appropriate Riemann solver technique. An explicit or an implicit dissipation, introduced in such techniques, is necessary to solve the Euler equations to solve flow discontinuit

A. Arbey, F. Mahmoudi

With the start-up of the LHC, we can hope to find evidences for new physics beyond the Standard Model, and particle candidates for dark matter. Determining the parameters of the full underlying theory will be a long process requiring the combination of LHC and ILC data, flavor physics constraints, and cosmological observations. However, the Very Early Univer

Perrine Berger, Jerome Bourderionnet, Guilhem de Valicourt, Romain Brenot

We experimentally demonstrate enhanced slow and fast light by forced coherent population oscillations (CPOs) in a SOA. This approach is shown to rely on the interference between two different contributions. This opens the possibility to conceive a controllable RF phase shifter based on this set-up.