November 2007 arXiv papers — page 15

Je-an Gu

An oscillating scalar field as a quintessence model for dark energy is proposed. The case of a power-law potential is particularly intriguing and is the focus of the present article. In this model the equation of state w_{OQ} of dark energy is a constant determined simply by the power n in the potential through w_{OQ} = (n-2)/(n+2). Accordingly, when 0 < n <

Floris van der Tak

This review discusses recent results on the astrochemistry of (mostly high-mass) star-forming regions. After an introduction on the use of chemistry in astrophysics and some basic concepts of astrochemistry, specific results are presented. Highlighted areas are the use of chemistry in the search for massive circumstellar disks, the interaction of molecular c

E. A. Kuraev, V. V. Bytev, S. Bakmaev, E. N. Antonov

In frames of effective Regge action the vertices describing conversion of two reggeized gluons to one two and three ordinary gluons was constructed. The self-consistency: Bose symmetry and gauge invariance properties checks was shown to be fulfilled. The simplest one with creation of a single gluon was intensively verified in programs of experimental and the

P. Cerejeiras, N. Vieira

In this paper we will study the existence of fundamental solutions for the explicit and implicit backward time dependent Schodinger equation, via discrete Fourier transform and its symbol for the Laplace operator. In both cases we will prove that the discrete fundamental solutions obtained converges to the continuous fundamental solution in the $l_1-$norm se

Bilha Nissenson

The formulation of quantum theory does not comply with the notion of objective existence of elementary particles. Objective existence independent of observation implies the distinguishability of elementary particles. In other words: If elementary particles have an objective existence independent of observations, then they are distinguishable. Or if elementar

G. Patanchon, P. A. R. Ade, J. J. Bock, E. L. Chapin

We describe a map-making method which we have developed for the Balloon-borne Large Aperture Submillimeter Telescope (BLAST) experiment, but which should have general application to data from other submillimeter arrays. Our method uses a Maximum Likelihood based approach, with several approximations, which allows images to be constructed using large amounts

U. Håkanson, M. Agio, S. Kühn, L. Rogobete

We present experiments in which the interaction of a single gold nanoparticle with glass substrates or with another gold particle can be tuned by in-situ control of their separations using scanning probe technology. We record the plasmon resonances of the coupled systems as a function of the polarization of the incident field and the particle position. The d

L. Lamata, J. Leon, D. Perez-Garcia, D. Salgado

We study the possibility for a global unitary applied on an arbitrary number of qubits to be decomposed in a sequential unitary procedure, where an ancillary system is allowed to interact only once with each qubit. We prove that sequential unitary decompositions are in general impossible for genuine entangling operations, even with an infinite-dimensional an

H. C. Spruit

Possible origins of the magnetic fields of neutron stars include inheritance from the main sequence progenitor and dynamo action at some stage of evolution of progenitor. Inheritance is not sufficient to explain the fields of magnetars. Energetic considerations point to differential rotation in the final stages of core collapse process as the most likely sou

S. Brener, H. Hafermann, A. N. Rubtsov, M. I. Katsnelson

In this paper, we show how the two-particle Green function (2PGF) can be obtained within the framework of the Dual Fermion approach. This facilitates the calculation of the susceptibility in strongly correlated systems where long-ranged non-local correlations cannot be neglected. We formulate the Bethe-Salpeter equations for the full vertex in the particle-p

P. O. Kazinski

A notion of stochastic deformation is introduced and the corresponding algebraic deformation procedure is developed. This procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). This method is demonstrated on diverse relativistic and nonrelativisti

Sławomir Dinew, Zhou Zhang

We generalize and strenghten Kołodziej&#39;s stability theorem. In particular we give sharp stability exponent and treat the case with more singular right hand side of the Monge-Ampère equation.

Teppei Okumura, Takahiko Matsubara, Daniel J. Eisenstein, Issha Kayo

We study the large-scale anisotropic two-point correlation function using 46,760 luminous red galaxies at redshifts 0.16 -- 0.47 from the Sloan Digital Sky Survey. We measure the correlation function as a function of separations parallel and perpendicular to the line-of-sight in order to take account of anisotropy of the large-scale structure in redshift spa

K. B. Alkalaev

The Lagrangian frame-like formulation of free higher spin symmetric bosonic AdS(d) fields is given within a manifestly sp(2) invariant framework. It is designed to deal with infinite multiplets of fields appearing as gauge connections of the higher spin algebras.

Liliana Arrachea, Carlos Naón, Mariano Salvay

We investigate the behavior of the four-terminal resistance $R_{4pt}$ in a quantum wire described by a Luttinger liquid in two relevant situations: (i) in the presence of a single impurity within the wire and (ii) under the effect of asymmetries introduced by dirty voltage probes. In the first case, interactions leave a signature in a power law behavior of $

M. Kachelriess, E. Parizot, D. V. Semikoz

We discuss the GZK horizon of protons and present a method to constrain the injection spectrum of ultrahigh energy cosmic rays (UHECRs) from supposedly identified extragalactic sources. This method can be applied even when only one or two events per source are observed and is based on the analysis of the probability for a given source to populate different e

Santos Bravo Yuste, Andrés Santos, Mariano López de Haro

The depletion force and depletion potential between two in principle unequal &#34;big&#34; hard spheres embedded in a multicomponent mixture of &#34;small&#34; hard spheres are computed using the Rational Function Approximation method for the structural properties of hard-sphere mixtures [S. B. Yuste, A. Santos, and M. López de Haro, J. Chem. Phys. {\bf 108}

M. Chiapparini, M. E. Bracco, A. Delfino, M. Malheiro

By using a parametrization of the non-linear Walecka model which takes into account the binding energy of different hyperons, we present a study of particle production yields measured in central Au-Au collision at RHIC. Two sets of different hyperon-meson coupling constants are employed in obtaining the hadron production and chemical freeze-out parameters. T

Achilleas Lazarides, Bert Van Schaeybroeck

We present a theoretical study of the collective excitations of a trapped imbalanced fermion gas at unitarity, when the system consists of a superfluid core and a normal outer shell. We formulate the relevant boundary conditions and treat the normal shell both hydrodynamically and collisionlessly. For an isotropic trap, we calculate the mode frequencies as a

David W. McKee, Jerome K. Busenitz, Igor Ostrovskiy

We report on the construction and performance of a calibration source for KamLAND using the reaction C-13(alpha,n)O-16 with Po-210 as the alpha progenitor. The source provides a direct measurement of this background reaction in our detector, high energy calibration points for the detector energy scale, and data on quenching of the neutron visible energy in K

A. C. Clark, J. D. Maynard, M. H. W. Chan

We have studied the thermal history of the resonant frequency of a torsional oscillator containing solid 4He. We find that the magnitude of the frequency shift that occurs below 100 mK is multivalued in the low temperature limit, with the exact value depending on how the state is prepared. This result can be qualitatively explained in terms of the motion and

Piotr Trocha, Józef Barnaś

Spin-dependent electronic transport through a quantum dot side-coupled to two quantum dots and attached to ferromagnetic leads with collinear (parallel and antiparallel) magnetizations is analyzed theoretically. The intra-dot Coulomb correlations are taken into account, whereas the inter-dot ones are neglected. Transport characteristics, i.e. conductance and

Gerardo Adesso, Giulio Chiribella

We provide a quantum benchmark for teleportation and storage of single-mode squeezed states with zero displacement and a completely unknown degree of squeezing along a given direction. For pure squeezed input states, a fidelity higher than 81.5% has to be attained in order to outperform any classical strategy based on an estimation of the unknown squeezing a

Chiaki Hikage, Peter Coles, Margherita Grossi, Lauro Moscardini

We study the effect of primordial non-Gaussianity on the development of large-scale cosmic structure using high-resolution N-body simulations. In particular, we focus on the topological properties of the &#34;cosmic web&#34;, quantitatively characterized by the Minkowski Functionals, for models with quadratic non-linearities with different values of the usua

M. Kreuzer, C. Mayrhofer, R. C. Rashkov

Recently Maldacena and Swanson suggested a new limit of string theory on the $AdS_5\times S^5$ background, the so called near flat space limit. The resulting reduced theory interpolates between the pp-wave limit and giant magnon type string solutions. It was shown that the reduced model possess many features of the original theory. On the other hand, theorie

Songbai Chen, Bin Wang, Ru-Keng Su, W. -Y Pauchy Hwang

We study the absorption probability and Hawking radiation of the scalar field in the rotating black holes on codimension-2 branes. We find that finite brane tension modifies the standard results in Hawking radiation if compared with the case when brane tension is completely negligible. We observe that the rotation of the black hole brings richer physics. Non

Giovanni Ossola, Costas G. Papadopoulos, Roberto Pittau

We present a program that implements the OPP reduction method to extract the coefficients of the one-loop scalar integrals from a user defined (sub)-amplitude or Feynman Diagram, as well as the rational terms coming from the 4-dimensional part of the numerator. The rational pieces coming from the epsilon-dimensional part of the numerator are treated as an ex

Uwe Aickelin, Edmund Burke, Jingpeng Li

This paper proposes a new memetic evolutionary algorithm to achieve explicit learning in rule-based nurse rostering, which involves applying a set of heuristic rules for each nurse&#39;s assignment. The main framework of the algorithm is an estimation of distribution algorithm, in which an ant-miner methodology improves the individual solutions produced in e

A. Bueno, J. Lozano, A. J. Melgarejo, F. J. Munoz

There is growing interest in the use of noble liquid detectors to study particle properties and search for new phenomena. In particular, they are extremely suitable for performing direct searches for dark matter. In this kind of experiments, the light produced after an interaction within the sensitive volume is usually read-out by photomultipliers. The need

G. Heinrich, T. Huber, D. Maitre

In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N. Working in dimensional regularisation, we express one of the integrals in a closed form which is exact to all orders in

A. A. Lopatin, A. N. Zubkov

This paper is a survey on invariants of representations of quivers and their generalizations. We present the description of generating systems for invariants and relations between generators.

Jean-Marc Bouclet

We prove local in time Strichartz estimates without loss for the restriction of the solution of the Schroedinger equation, outside a large compact set, on a class of asymptotically hyperbolic manifolds.

Kenta Kiuchi, Hisa-aki Shinkai

We present our numerical comparisons between the BSSN formulation widely used in numerical relativity today and its adjusted versions using constraints. We performed three testbeds: gauge-wave, linear wave, and Gowdy-wave tests, proposed by the Mexico workshop on the formulation problem of the Einstein equations. We tried three kinds of adjustments, which we

Alejandra Kandus, Christos G. Tsagas

We generalise the relativistic expression of Ohm&#39;s law by studying a multi-fluid system of charged species using the 1+3 covariant formulation of general relativistic electrodynamics. This is done by providing a fully relativistic, fully nonlinear propagation equation for the spatial component of the electric 4-current. Our analysis proceeds along the li

Mark E. Perel&#39;man, Vitali A. Tatartchenko

Crystallization and vapor condensation are considered as processes of sequential entering of single atoms/molecules into condensate. The latent heat can be carry away by radiation of characteristic frequencies generated in the course of transition. The estimated dependences of latent (radiated) energy of boiling on temperature confirm and prove the well-know

C. Bambi, A. Drago

The formation of a strange or hybrid star from a neutron star progenitor is believed to occur when the central stellar density exceeds a critical value. If the transition from hadron to quark matter is of first order, the event has to release a huge amount of energy in a very short time and we would be able to observe the phenomenon even if it is at cosmolog

Piotr Stefanski

We propose a spin polarizer device composed of a quantum dot connected to the spin polarized leads. The spin control of the current flowing through the device is entirely due to the Coulomb interactions present inside the dot. We show that the initial polarization present in the source lead can be reverted or suppressed just by manipulating the gate voltage

Franck Laloë, William J. Mullin

We discuss the properties of two Bose-Einstein condensates in different spin states, represented quantum mechanically by a double Fock state. Individual measurements of the spins of the particles are performed in transverse directions (perpendicular to the spin quantization axis), giving access to the relative phase of the two macroscopically occupied states

A. D. Christianson, M. D. Lumsden, M. Angst, Z. Yamani

We present single-crystal neutron diffraction measurements on multiferroic LuFe2O4 showing phase transitions at 240 and 175 K. Magnetic reflections are observed below each transition indicating that the magnetic interactions in LuFe2O4 are 3-dimensional (3D) in character. The magnetic structure is refined as a ferrimagnetic spin configuration below the 240 K

C. Jaudet, D. Vignolles, A. Audouard, J. Levallois

The de Haas-van Alphen effect was observed in the underdoped cuprate YBa$_2$Cu$_3$O$_{6.5}$ via a torque technique in pulsed magnetic fields up to 59 T. Above an irreversibility field of $\sim$30 T, the magnetization exhibits clear quantum oscillations with a single frequency of 540 T and a cyclotron mass of 1.76 times the free electron mass, in excellent ag

Roman Romanov

We give an example of an operator with different weak and strong absolutely continuous subspaces, and a counterexample to the duality problem for the spectral components. Both examples are optimal in the scale of compact operators.

Charles Torossian

This article is a survey about applications of bi-quantization theory in Lie theory. We focus on a conjecture of M. Duflo. Most of the applications are coming from our article with Alberto Cattaneo and some extensions are relating discussions with my student. The end of the article is completely new. We prove that the conjecture E=1 implies the Kashiwara-Ver

C. Adam, N. Grandi, J. Sanchez-Guillen, A. Wereszczynski

K fields, that is, fields with a non-standard kinetic term, allow for soliton solutions with compact support, i.e., compactons. Compactons in 1+1 dimensions may give rise to topological defects of the domain wall type and with finite thickness in higher dimensions. Here we demonstrate that, for an appropriately chosen kinetic term, propagation of linear pert

Marcos Moshinsky, Emerson Sadurni, Adolfo del Campo

A direct procedure for determining the propagator associated with a quantum mechanical problem was given by the Path Integration Procedure of Feynman. The Green function, which is the Fourier Transform with respect to the time variable of the propagator, can be derived later. In our approach, with the help of a Laplace transform, a direct way to get the ener

Pierre Jop, Sergio Ciliberto, Artem Petrosyan

We study experimentally the fluctuations of the injected and dissipated energy in a system of a colloidal particle trapped in a double well potential periodically modulated by an external perturbation. The work done by the external force and the dissipated energy are measured close to the stochastic resonance where the injected power is maximum. We show that

Nakia Carlevaro, Orchidea Maria Lecian, Giovanni Montani

Torsion represents the most natural extension of General Relativity and it attracted interest over the years in view of its link with fundamental properties of particle motion. The bulk of the approaches concerning the torsion dynamics focus their attention on their geometrical nature and they are naturally led to formulate a non-propagating theory. Here we

Viada Evelina

Let C be an algebraic curve in a power of an elliptic curve, both defined over the algebraic numbers. We show that the set of algebraic points of C which satisfy certain conditions is a finite set. This result has implications with the Pink-Zilber Conjeture and the Mordel-Lang plus Bogomolov Theorem for curves.

Viada Evelina

Let V be an algebraic variety embedded in a power of an elliptic curve, both defined over the algebraic numbers. We show that the set of algebraic points of V which are of bounded height and which satisfy certain algebraic conditions are a non-dense subset of V. This result has implications in the context of the Pink-Zilber Conjecture and Mordel-Lang plus Bo

Katsushi Ito, Horatiu Nastase, Koh Iwasaki

We extend the AdS/CFT prescription of Alday and Maldacena to finite temperature $T$, defining the amplitude for gluon scattering in ${\cal N}=4$ Super Yang-Mills at strong coupling from string theory. It is defined by a lightlike &#39;&#39;Wilson loop&#39;&#39; living at the horizon of the T-dual to the black hole in AdS space. Unlike the zero temperature ca

Ji-Haeng Huh, Jihn E. Kim, Jong-Chul Park, Seong Chan Park

We present a possible explanation of the recently observed 511 keV $γ$-ray anomaly with a new ``millicharged&#39;&#39; fermion. The new fermion is light (${\cal O}({\rm MeV})$) but has never been observed by any collider experiments mainly because of its tiny electromagnetic charge $εe$. We show that constraints from its relic density in the Universe and col

J. Gasser, V. E. Lyubovitskij, A. Rusetsky

We review the theory of hadronic atoms in QCD + QED, based on a non-relativistic effective Lagrangian framework. We first provide an introduction to the theory, and then describe several applications: meson-meson, meson-nucleon atoms and meson-deuteron compounds. Finally, we compare the quantum field theory framework used here with the traditional approach,

Eylee Jung, Mi-Ra Hwang, DaeKil Park, Jin-Woo Son

We conjecture that criterion for perfect quantum teleportation is that the Groverian entanglement of the entanglement resource is $1/\sqrt{2}$. In order to examine the validity of our conjecture we analyze the quantum teleportation and superdense coding with $|Φ> = (1/\sqrt{2}) (|00q_1> + |11q_2>)$, where $|q_1>$ and $|q_2>$ are arbitrary normalized single q

R. Mohanta, A. K. Giri

We investigate the effect of unparticles in the pure $ b \to d $ penguin processes $ B^0 \to K^0 \bar K^0$ and $B^{+,0} \to ϕπ^{+,0} $. Since these processes receive dominant contributions due to the {\it top} quark in the loop, direct and mixing-induced CP asymmetry parameters in these processes are expected to be vanishingly small in the standard model. We

R. Asgari, M. M. Vazifeh, M. R. Ramezanali, E. Davoudi

We calculate the ground-state energy of Dirac electrons in graphene in the presence of disorder. We take randomly distributed charged impurities at a fixed distance from the graphene sheet and surface fluctuations (ripples) as the main scattering mechanisms. Mode-coupling approach to scattering rate and random-phase approximation for ground-state energy inco

Chun-Hsu Su, Andrew D. Greentree, Lloyd C. L. Hollenberg

We analyze a nitrogen-vacancy (NV^-) colour centre based single photon source based on cavity Purcell enhancement of the zero phonon line and suppression of other transitions. Optimal performance conditions of the cavity-centre system are analyzed using Master equation and quantum trajectory methods. By coupling the centre strongly to a high-finesse optical

X. Q. Yan, C. Lin, Z. M. Sheng, Z. Y. Guo

The acceleration of ions in the interaction of circular polarized laser pulses with overdense plasmas is investigated. For circular polarization laser pulses, the quasi-equilibrium for electrons is established due to the light pressure and the electrostatic field built up at the interacting front of the laser pulse. The ions located within the skin-depth of

J. G. Sumner, M. A. Charleston, L. S. Jermiin, P. D. Jarvis

We explore model based techniques of phylogenetic tree inference exercising Markov invariants. Markov invariants are group invariant polynomials and are distinct from what is known in the literature as phylogenetic invariants, although we establish a commonality in some special cases. We show that the simplest Markov invariant forms the foundation of the Log

Liu Wen-jie, Chen Han-wu, Li Zhi-qiang, Liu Zhi-hao

Two protocols of quantum direct communication with authentication [Phys. Rev. A 73, 042305(2006)] were recently indicated to be insecure against the authenticator Trent&#39;s attacks [Phys. Rev. A 75, 026301(2007)]. We present two efficient protocols by using four Pauli operations, which are secure against inner Trent&#39;s attacks as well as outer Eve&#39;s

Vladimir Nikiforov

Answering some questions of Gutman, we show that, except for four specific trees, every connected graph G of order n, with no cycle of order 4 and with maximum degree at most 3, has energy greater that its order. Here, the energy of a graph is the sum of the moduli of its eigenvalues. We give more general theorems and state two conjectures.

Leonid Gurvits

Let $p$ be a homogeneous polynomial of degree $n$ in $n$ variables, $p(z_1,...,z_n) = p(Z)$, $Z \in C^{n}$. We call such a polynomial $p$ {\bf H-Stable} if $p(z_1,...,z_n) \neq 0$ provided the real parts $Re(z_i) > 0, 1 \leq i \leq n$. This notion from {\it Control Theory} is closely related to the notion of {\it Hyperbolicity} used intensively in the {\it P

Sergei I. Ipatov, Alexander S. Kutyrev, Greg J. Madsen, John C. Mather

The simulated Doppler shifts of the solar Mg I Fraunhofer line produced by scattering on the solar light by asteroidal, cometary, and trans-Neptunian dust particles are compared with the shifts obtained by Wisconsin H-Alpha Mapper (WHAM) spectrometer. The simulated spectra are based on the results of integrations of the orbital evolution of particles. The de

Sergei Chmutov

We generalize the natural duality of graphs embedded into a surface to a duality with respect to a subset of edges. The dual graph might be embedded into a different surface. We prove a relation between the signed Bollobas-Riordan polynomials of dual graphs. This relation unifies various recent results expressing the Jones polynomial of links as specializati

Leonhard Euler

E158 in the Enestrom index. Translation of the Latin original &#34;Observationes analyticae variae de combinationibus&#34; (1741). This paper introduces the problem of partitions, or partitio numerorum (the partition of integers). In the first part of the paper Euler looks at infinite symmetric functions. He defines three types of series: the first denoted w

Mikko Stenlund

We study a Hamiltonian describing a pendulum coupled with several anisochronous oscillators, devising an asymptotic expansion for the splitting (matrix) associated with a homoclinic point. This expansion consists of contributions that are manifestly exponentially small in the limit of vanishing hyperbolicity, by a shift-of-contour argument. Hence, we infer a

Gabriela Barenboim, Joseph Lykken

Scalar-tensor gravity is the simplest and best understood modification of general relativity, consisting of a real scalar field coupled directly to the Ricci scalar curvature. Models of this type have self-accelerating solutions. In an example inspired by string dilaton couplings, scalar-tensor gravity coupled to ordinary matter exhibits a de Sitter type exp

Daqing Wan

These are the notes from the summer school in Göttingen sponsored by NATO Advanced Study Institute on Higher-Dimensional Geometry over Finite Fields that took place in 2007. The aim was to give a short introduction on zeta functions over finite fields, focusing on moment zeta functions and zeta functions of affine toric hypersurfaces.

Nassiredin M. Mojarad, Vahid Sandoghdar, Mario Agio

We study the modification of the far-field cross sections and the near-field enhancement for gold and silver nanospheres illuminated by a tightly focused beam. Using a multipole-expansion approach we obtain an analytical solution to the scattering problem and provide insight on the effects of focusing on the optical response. Large differences with respect t

Jean-Louis Loday, Todor Popov

We consider the parastatistics algebra with both parabosonic and parafermionic operators and show that the states in the universal parastatistics Fock space are in bijection with the Super Semistandard Young Tableaux (SSYT). Using deformation of the parastatistics algebra we get a monoid structure on SSYT which is a super version of the plactic monoid.

Jose Gomez-Torrecillas, Joost Vercruysse

We develop a Galois (descent) theory for comonads within the framework of bicategories. We give generalizations of Beck&#39;s theorem and the Joyal-Tierney theorem. Many examples are provided, including classical descent theory, Hopf-Galois theory over Hopf algebras and Hopf algebroids, Galois theory for corings and group-corings, and Morita-Takeuchi theory

Daniel C. Guariento, J. E. Horvath, P. S. Custódio, J. A. de Freitas Pacheco

In this work we extend previous work on the evolution of a Primordial Black Hole (PBH) to address the presence of a dark energy component with a super-negative equation of state as a background, investigating the competition between the radiation accretion, the Hawking evaporation and the phantom accretion, the latter two causing a decrease on black hole mas

Bryna Kra, Bernard Host

A key tool in recent advances in understanding arithmetic progressions and other patterns in subsets of the integers is certain norms or seminorms. One example is the norms on $\Z/N\Z$ introduced by Gowers in his proof of Szemerédi&#39;s Theorem, used to detect uniformity of subsets of the integers. Another example is the seminorms on bounded functions in a

Nathaniel Johnston, David W. Kribs, Vern I. Paulsen

The diamond and completely bounded norms for linear maps play an increasingly important role in quantum information science, providing fundamental stabilized distance measures for differences of quantum operations. Based on the theory of completely bounded maps, we formulate an algorithm to compute the norm of an arbitrary linear map. We present an implement

M. G. Vergniory, J. M. Pitarke, P. M. Echenique

We report many-body calculations of the self-energy and lifetime of Shockley and image states on the (100) and (111) surfaces of Cu that go beyond the $GW$ approximation of many-body theory. The self-energy is computed in the framework of the GWΓapproximation by including short-range exchange-correlation (XC) effects both in the screened interaction W (beyon

Debasish Chatterjee, Daniel Liberzon

This article is concerned with stability analysis and stabilization of randomly switched nonlinear systems. These systems may be regarded as piecewise deterministic stochastic systems: the discrete switches are triggered by a stochastic process which is independent of the state of the system, and between two consecutive switching instants the dynamics are de

Holger Ahlers, Andreas Engel

Building on a variant of the Jarzynski equation we propose a new method to numerically determine the prior-predictive value in a Bayesian inference problem. The method generalizes thermodynamic integration and is not hampered by equilibration problems. We demonstrate its operation by applying it to two simple examples and elucidate its performance. In the ca

Ted Hurley

A general method for constructing convolutional codes from units in Laurent series over matrix rings is presented. Using group ring as matrix rings, this forms a basis for in-depth exploration of convolutional codes from group ring encoding, wherein the ring in the group ring is itself a group ring. The method is used to algebraically construct series of con

Gabriel Cardona, Francesc Rossello, Gabriel Valiente

Phylogenetic networks are a generalization of phylogenetic trees that allow for the representation of evolutionary events acting at the population level, like recombination between genes, hybridization between lineages, and lateral gene transfer. While most phylogenetics tools implement a wide range of algorithms on phylogenetic trees, there exist only a few

Yu. A. Simonov

Mechanism of di-pion transitions $nS\to n&#39;Sππ(n=3,2; n&#39;=2,1)$ in bottomonium and charmonium is studied with the use of the chiral string-breaking Lagrangian allowing for the emission of any number of $π(K,η),$ and not containing fitting parameters. The transition amplitude contains two terms, $M=a-b$, where first term (a) refers to subsequent one-pio

B. Bako, I. Groma, G. Gyorgyi, G. T. Zimanyi

The dynamics of dislocations is reported to exhibit glassy properties. We study numerically various versions of 2d edge dislocation systems in the absence of externally applied stress. Two types of glassy behavior are identified: (i) dislocations gliding along randomly placed, but fixed, axes exhibit relaxation to their spatially disordered stable state; (ii

J. A. Gracey

We summarize recent results for the Gribov-Zwanziger Lagrangian which includes the effect of restricting the path integral to the first Gribov region. These include the two loop MSbar and one loop MOM gap equations for the Gribov mass.

A. C. D. van Enter, W. M. Ruszel

We study the Gibbsian character of time-evolved planar rotor systems on Z^d, d at least 2, in the transient regime, evolving with stochastic dynamics and starting with an initial Gibbs measure. We model the system by interacting Brownian diffusions, moving on circles. We prove that for small times and arbitrary initial Gibbs measures ν, or for long times and

Trueman MacHenry, Kieh Wong

We give a representation of the classical theory of multiplicative arithmetic functions (MF)in the ring of symmetric polynomials. The basis of the ring of symmetric polynomials that we use is the isobaric basis, a basis especially sensitive to the combinatorics of partitions of the integers. The representing elements are recursive sequences of Schur polynomi

M. Cavallini, F. Biscarini, P. Nozar, V. Dediu

The surface spin polarization in the epitaxial films of a prototype manganite, La0.7Sr0.3MnO3, has been investigated by Scanning Tunneling Spectroscopy with ferromagnetic SP tips at room temperature. The manganite surface splits into ferromagnetic (FM) and paramagnetic(PM) regions characterized by metallic and insulating like behavior respectively. Spin pola

Karthik Bharath, Swarnamala Sirsi, A R Usha Devi

The quantum analogue of the classical characteristic function for a spin 1/2 assembly is considered and the probability mass function of the random vector associated with the assembly is derived. It is seen that the positive regions of Wigner and Margenau-Hill quasi distributions for the three components of spin, correspond to a trivariate probability mass f

A. Brandenburg, P. J. Käpylä, D. Mitra, D. Moss

The motivation for considering distributed large scale dynamos in the solar context is reviewed in connection with the magnetic helicity constraint. Preliminary accounts of 3-dimensional direct numerical simulations (in spherical shell segments) and simulations of 2-dimensional mean field models (in spherical shells) are presented. Interesting similarities a

M. A. Sumour, A. H. El-Astal, M. A. Radwan, M. M. Shabat

In this paper we study urban segregation of two different communities A and B, poor and rich, distributed randomly on finite samples, to check cheap and expensive residences. For this purpose we avoid the complications of the Schelling model which are not necessary and instead we use the Ising model on 500 x 500 square lattice, which give similar results, wi

D. G. Naugle, B. I. Belevtsev, K. D. D. Rathnayaka, S. -I. Lee

The metamagnetic transitions in single-crystal ErNi$_2$B$_2$C have been studied at 1.9 K with a Quantum Design torque magnetometer. The critical fields of the transitions depend crucially on the angle between applied field and the easy axis [100]. Torque measurements have been made while changing angular direction of the magnetic field (parallel to basal tet

L. Tolos, B. Friman, A. Schwenk

We calculate the neutron matter equation of state at finite temperature based on low-momentum two- and three-nucleon interactions. The free energy is obtained from a loop expansion around the Hartree-Fock energy, including contributions from normal and anomalous diagrams. We focus on densities below saturation density with temperatures T <= 10 MeV and compar

I. I. Antokhin, G. Rauw, J. -M. Vreux, K. A. van der Hucht

X-ray properties of the stellar population in the Carina OB1 association are examined with special emphasis on early-type stars. Their spectral characteristics provide some clues to understanding the nature of X-ray formation mechanisms in the winds of single and binary early-type stars. A timing and spectral analysis of five observations with XMM-Newton is

David Gerard-Varet

We consider the Navier-Stokes equation in a domain with irregular boundaries. The irregularity is modeled by a spatially homogeneous random process, with typical size $\eps \ll 1$. In a parent paper, we derived a homogenized boundary condition of Navier type as $\eps \to 0$. We show here that for a large class of boundaries, this Navier condition provides a

Julius Borcea, Boris Shapiro, Michael Shapiro

Given a $(k+1)$-tuple $A, B_1,...,B_k$ of $(m\times n)$-matrices with $m\le n$ we call the set of all $k$-tuples of complex numbers $\{\la_1,...,\la_k\}$ such that the linear combination $A+\la_1B_1+\la_2B_2+...+\la_kB_k$ has rank smaller than $m$ the {\it eigenvalue locus} of the latter pencil. Motivated primarily by applications to multi-parameter generali

Mauro G. Rickes, Miriani G. Pastoriza, Charles Bonatto

The stellar population, metallicity distribution and ionized gas in the elliptical galaxies NGC 6868 and NGC 5903 are investigated in this paper by means of long-slit spectroscopy and stellar population synthesis. Lick indices in both galaxies present a negative gradient indicating an overabundance of Fe, Mg, Na and TiO in the central parts with respect to t

Eric Laporte, Christian Leclère, Maria Carmelita P. Dias

We discuss the characteristics and behaviour of two parallel classes of verbs in two Romance languages, French and Portuguese. Examples of these verbs are Port. abater [gado] and Fr. abattre [bétail], both meaning &#34;slaughter [cattle]&#34;. In both languages, the definition of the class of verbs includes several features: - They have only one essential co

Nelson Pinto-Neto, Bernardo M. O. Fraga

Cosmological models with two interacting fluids, each satisfying the strong energy condition, are studied in the framework of classical General Relativity. If the interactions are phenomenologically described by a power law in the scale factor, the two initial interacting fluids can be equivalently substituted by two non interacting effective fluids, where o

S. -J. Paardekooper, G. Mellema

We study the interaction of a low-mass planet with a protoplanetary disk with a realistic treatment of the energy balance by doing radiation-hydrodynamical simulations. We look at accretion and migration rates and compare them to isothermal studies. We used a three-dimensional version of the hydrodynamical method RODEO, together with radiative transport in t

Heping He, Thomas A. Severini

Approximations to the modified signed likelihood ratio statistic are asymptotically standard normal with error of order $n^{-1}$, where $n$ is the sample size. Proofs of this fact generally require that the sufficient statistic of the model be written as $(\hatθ,a)$, where $\hatθ$ is the maximum likelihood estimator of the parameter $θ$ of the model and $a$

Erik I. Broman

The ordinary contact process is used to model the spread of a disease in a population. In this model, each infected individual waits an exponentially distributed time with parameter 1 before becoming healthy. In this paper, we introduce and study the contact process in a randomly evolving environment. Here we associate to every individual an independent two-

Luzi Bergamin, Rene Meyer

Using the recently found first order formulation of two-dimensional dilaton gravity with boundary, we perform a Hamiltonian analysis and subsequent path integral quantization. The importance of the boundary terms to obtain the correct quantum result are outlined and the quantum triviality of the theory is shown to hold with this modification as well. We comp

Chunjing Xu, Jianzhuang Liu, Xiaoou Tang

Recent spectral clustering methods are a propular and powerful technique for data clustering. These methods need to solve the eigenproblem whose computational complexity is $O(n^3)$, where $n$ is the number of data samples. In this paper, a non-eigenproblem based clustering method is proposed to deal with the clustering problem. Its performance is comparable

N. C. Hambly, R. S. Collins, N. J. G. Cross, R. G. Mann

We describe the WFCAM Science Archive (WSA), which is the primary point of access for users of data from the wide-field infrared camera WFCAM on the United Kingdom Infrared Telescope (UKIRT), especially science catalogue products from the UKIRT Infrared Deep Sky Survey (UKIDSS). We describe the database design with emphasis on those aspects of the system tha