March 2008 arXiv papers — page 37

Richard J. Mathar

Sums over inverse s-th powers of semiprimes and k-almost primes are transformed into sums over products of powers of ordinary prime zeta functions. Multinomial coefficients known from the cycle decomposition of permutation groups play the role of expansion coefficients. Founded on a known convergence acceleration for the ordinary prime zeta functions, the su

Richard Bardoux, Thierry Guillet, B. Gil, P. Lefebvre

We report micro-photoluminescence studies of single GaN/AlN quantum dots grown along the (0001) crystal axis by molecular beam epitaxy on Si(111) substrates. The emission lines exhibit a linear polarization along the growth plane, but with varying magnitudes of the polarization degree and with principal polarization axes that do not necessarily correspond to

Bernhard H. Haak, Birgit Jacob, Sandra Pott, Jonathan R. Partington

This article studies Volterra evolution equations from the point of view of control theory, in the case that the generator of the underlying semigroup has a Riesz basis of eigenvectors. Conditions for admissibility of the system's control operator are given in terms of the Carleson embedding properties of certain discrete measures. Moreover, exact and nu

M. Bahr, S. Gieseke, M. A. Gigg, D. Grellscheid

In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of important hard scattering processes are available, together with an interface via the Les Houches Accord to specialized matrix element generators for additional process

M. Cramer, A. Serafini, J. Eisert

The Lieb-Robinson theorem states that locality is approximately preserved in the dynamics of quantum lattice systems. Whenever one has finite-dimensional constituents, observables evolving in time under a local Hamiltonian will essentially grow linearly in their support, up to exponentially suppressed corrections. In this work, we formulate Lieb-Robinson bou

Kazuhide Ichikawa, Toyokazu Sekiguchi, Tomo Takahashi

We discuss how much we can probe the effective number of neutrino species N_nu with cosmic microwave background alone. Using the data of WMAP, ACBAR, CBI and BOOMERANG experiments, we obtain a constraint on the effective number of neutrino species as 0.96< N_nu <7.94 at 95% C.L. for a power-law LCDM flat universe model. The limit is improved to be 1.39 < N_n

Sergey V. Petoukhov

The Kronecker family of the genetic matrices is investigated, which is based on the genetic matrix [C T; A G], where C, T, A, G are the letters of the genetic alphabet. The matrix [C T; A G] in the second Kronecker power is the (4*4)-matrix of 16 duplets. The matrix [C T; A G] in the third Kronecker power is the (8*8)-matrix of 64 triplets. It is significant

Karol Kolodziej, Szymon Szczypinski

The top quark Yukawa coupling to the intermediate mass Higgs boson can be determined in the reaction e+e- -> t anti-t H that, after taking into account decays, will be detected at the International Linear Collider through reactions with 8 particles in the final state. Such 2 -> 8 reactions receive contributions from tens thousands of Feynman diagrams, alread

A. V. Bondarenko, A. A. Zavgorodniy, D. A. Lotnik, M. A. Obolenskii

We present the results of an experimental study of vortex dynamics in non-twinned $YBa_2Cu_3O_{6,87}$ crystal. It is found that critical currents $J_c$ and $J_{c,dyn}$, which correspond to the pinning force in the thermal creep and flux flow mode, respectively, non-monotonically vary with the magnetic field. However, the minimum in the $J_{c,dyn}(H)$ depende

Marc Hoffmann, Nathalie Krell

We explore statistical inference in self-similar conservative fragmentation chains when only approximate observations of the sizes of the fragments below a given threshold are available. This framework, introduced by Bertoin and Martinez [Adv. Appl. Probab. 37 (2005) 553--570], is motivated by mineral crushing in the mining industry. The underlying object th

Erik Van der Straeten, Jan Naudts

We study the three-dimensional persistent random walk with drift. Then we develop a thermodynamic model that is based on this random walk without assuming the Boltzmann-Gibbs form for the equilibrium distribution. The simplicity of the model allows us to perform all calculations in closed form. We show that, despite its simplicity, the model can be used to d

T. Pask, D. Barna, A. Dax, R. S. Hayano

We report the initial results from a systematic study of the hyperfine (HF) structure of antiprotonic helium (n,l) = (37,~35) carried out at the Antiproton Decelerator (AD) at CERN. We performed a laser-microwave-laser resonance spectroscopy using a continuous wave (cw) pulse-amplified laser system and microwave cavity to measure the HF transition frequencie

D. N. Sauer, P. A. Mazzali, S. Blondin, M. Stehle

The spectral properties of type Ia supernovae in the ultraviolet (UV) are investigated using the early-time spectra of SN 2001ep and SN 2001eh obtained using the Hubble Space Telescope (HST). A series of spectral models is computed with a Monte Carlo spectral synthesis code, and the dependence of the UV flux on the elemental abundances and the density gradie

Kimmo Kainulainen, Daniel Sunhede

We consider stability properties of spherically symmetric spacetimes of stars in metric f(R) gravity. We stress that these not only depend on the particular model, but also on the specific physical configuration. Typically configurations giving the desired $γ_{\rm PPN} \approx 1$ are strongly constrained, while those corresponding to $γ_{\rm PPN} \approx 1/2

Igor Leite Freire, Antonio Carlos Gilli Martins

We show that for any semilinear partial differential equation of order m, the infinitesimals of the independent variables depend only on the independent variables and, if m>1 and the equation is also linear in its derivatives of order m-1 of the dependent variable, then the infinitesimal of the dependent variable is at most linear on the dependent variable.

Joao Magueijo

If the speed of sound were vastly larger in the early Universe a near scale-invariant spectrum of density fluctuations could have been produced even if the Universe did not submit to conventional solutions to the horizon problem. We examine how the mechanism works, presenting full mathematical solutions and their heuristics. We then discuss several concrete

Mihyun Kang, Oleg Pikhurko, Alexander Ravsky, Mathias Schacht

Given a planar graph $G$, we consider drawings of $G$ in the plane where edges are represented by straight line segments (which possibly intersect). Such a drawing is specified by an injective embedding $π$ of the vertex set of $G$ into the plane. We prove that a wheel graph $W_n$ admits a drawing $π$ such that, if one wants to eliminate edge crossings by sh

X. W. C. Faber

The Bogomolov Conjecture is a finiteness statement about algebraic points of small height on a smooth complete curve defined over a global field. We verify an effective form of the Bogomolov Conjecture for all curves of genus at most 4 defined over a function field of characteristic zero. We recover the known result for genus 2 curves and in many cases impro

Audrey Cottet, Benoit Doucot, Wolfgang Belzig

We have calculated the finite-frequency current noise of a superconductor-ferromagnet quantum point contact (SF QPC). This signal is qualitatively affected by the spin-dependence of interfacial phase shifts (SDIPS) acquired by electrons upon reflection on the QPC. For a weakly transparent QPC, noise steps appear at frequencies or voltages determined directly

J. Goold, Th. Busch

We determine the exact many-body properties of a bosonic Tonks-Girardeau gas confined in a harmonic potential with a tunable $δ$-function barrier at the trap center. This is done by calculating the reduced single particle density matrix, the pair-distribution function, and momentum distribution of the gas as a function of barrier strength and particle number

F. Ren, B. Zheng, P. Chen

A dynamic herding model with interactions of trading volumes is introduced. At time $t$, an agent trades with a probability, which depends on the ratio of the total trading volume at time $t-1$ to its own trading volume at its last trade. The price return is determined by the volume imbalance and number of trades. The model successfully reproduces the power-

V. M. Vassilev, P. A. Djondjorov, I. M. Mladenov

Within the framework of the well-known curvature models, a fluid lipid bilayer membrane is regarded as a surface embedded in the three-dimensional Euclidean space whose equilibrium shapes are described in terms of its mean and Gaussian curvatures by the so-called membrane shape equation. In the present paper, all solutions to this equation determining cylind

El Hassan Saidi

Using the harmonic superspace method and the duality between real and complex representations of hypermultiplets, we compute the explicit scalar field expression of the quaternionic metric $G_{mn}$ of the moduli space SO(1,1)x[SO(4,k)/(SO(4)xSO(k))] of 6D N=2 supergravity with generic k Maxwell supermultiplets. The obtained metric includes the particular cas

Changhyun Ahn

We construct the type IIA nonsupersymmetric meta-stable brane configurations corresponding to the various N=1 supersymmetric gauge theories. The D6-branes are both displaced and rotated where these deformations are described as the mass term and quartic term for the fundamental flavors respectively. The multiplicity of the NS5-branes occurs in the superpoten

Jong-Phil Lee

A new type of scalar potential inspired by unparticles is proposed for the electroweak symmetry breaking. The interaction between the standard model fields and unparticle sector is described by the non-integral power of fields that originates from the nontrivial scaling dimension of the unparticle operator. We find that unlike the usual integral-power potent

Zhao-Long Wang, Wei Huang, Mu-Lin Yan

In this paper, we study the non-commutative Chern-Simons description of the hierarchy of quantum Hall states. Our method is based on the framework suggested by Susskind in hep-th/0101029. By using the area preserving diffeomorphism gauge symmetry of quasiparticle fluid, we show that non-commutative Chern-Simons description of the hierarchy construction of qu

H. X. Yang, Y. Zhang, C. Ma, H. F. Tian

Electronic ferroelectricity from charge ordering (CO) is currently a significant issue that has been extensively investigated in the charge/spin frustrated LuFe2O4 system. Chemical substitution and structural layer intercalation have been considered as potentially effective approaches in our recent study, and we herein report on the structural and multi-ferr

G. J. Gounaris, J. Layssac, F. M. Renard

We analyze the quark-gluon induced process $u g\to \tilde d\tchi_i^+$, including the one loop electroweak (EW) effects in the minimal supersymmetric model (MSSM). This process is determined by four helicity amplitudes, three of which are violating helicity conservation, and another one which respects it and is logarithmically enhanced at high energy. Combini

Elemer E. Rosinger

Two concepts of being Archimedean are defined for arbitrary categories.

Pedro T. Monteiro, Delphine Ropers, Radu Mateescu, Ana T. Freitas

Models of the dynamics of cellular interaction networks have become increasingly larger in recent years. Formal verification based on model checking provides a powerful technology to keep up with this increase in scale and complexity. The application of model-checking approaches is hampered, however, by the difficulty for non-expert users to formulate approp

Jun O. S. Yin, S. J. van Enk

Whereas single- and two-photon wave packets are usually treated as pure states, in practice they will be mixed. We study how entanglement created with mixed photon wave packets is degraded. We find in particular that the entanglement of a delocalized single-photon state of the electro-magnetic field is determined simply by its purity. We also discuss entangl

E. Shintani, S. Aoki, Y. Kuramashi

We have calculated the neutron electric dipole moment (NEDM) in the presence of the CP violating $θ$ term in lattice QCD with 2-flavor dynamical clover quarks, using the external electric field method. Accumulating a large number of statistics by the averages over 16 different source points and over forward and backward nucleon propagators, we have obtained

Hajime Ishimori, Tatsuo Kobayashi, Hiroshi Ohki, Yuji Omura

We study the supersymmetric model with $D_4 \times Z_2$ lepton flavor symmetry. We evaluate soft supersymmetry breaking terms, i.e. soft slepton masses and A-terms, which are predicted in the $D_4$ flavor model. We consider constraints due to experiments of flavor changing neutral current processes.

M. I. Petrov, Yu. S. Gokhfeld, D. A. Balaev, S. I. Popkov

The intragrain pinning in high-$T_c$ superconductor compounds Y$_{1-x}$RE$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-δ}$ with low concentration of RE (La, Ce, Pr) was investigated. Magnetic and transport measurements reveal that the pinning is maximal for the concentration of heterovalent RE such that the average distance between the impurity ions in the plane of rare-earth

Cenke Xu

We study the instabilities caused by four fermion interactions on algebraic spin liquids. Renormalization group (RG) is used for three types of previously proposed spin liquids on the square lattice: the staggered flux state of SU(2) spin system, the $π-$flux state of SU(4) spin system, and the $π-$flux state of SU(2) spin system. The low energy field theori

CLEO Collaboration, G. Bonvicini

Using 281/pb of data collected with the CLEO-c detector at the psi(3770) resonance, we have studied Cabibbo-suppressed decays of D mesons to final states with two kaons. We present results for the absolute branching fractions of the modes D^0 --> K^+ K^-, D^0 --> K^0_S K^0_S, and D^+ --> K^+ K^0_S. We measure B(D^0 --> K^+ K^-) = (4.08 +- 0.08 +- 0.09) x 10^

Yaling Yin, Yong Xia, Jianping Yin

We propose a promising scheme to decelerate a cw filtering out molecular beam using a red-detuned quasi-cw semi-Gaussian laser beam. By using Monte-Carlo simulation method, we demonstrate this optical Stark deceleration scheme, and study its decelerated dynamic process for a cw ND3 molecular beam as well as the dependence of the deceleration effect on the bo

M. Kliger, J. M. Francos

Evanescent random fields arise as a component of the 2-D Wold decomposition of homogenous random fields. Besides their theoretical importance, evanescent random fields have a number of practical applications, such as in modeling the observed signal in the space time adaptive processing (STAP) of airborne radar data. In this paper we derive an expression for

Keiichi Kimura, Akira Takamura, Tadashi Yoshikawa

We introduce a new index I_{Delta m_{31}^2} to find where is the better setup of the baseline length and energy to avoid as well as possible the uncertainty from the correlation between Delta m_{31}^2 and cos(delta) in nu_mu --> nu_mu long baseline experiments.

Zhongzhi Zhang, Shuigeng Zhou, Zhan Su, Tao Zou

In this paper, we define a stochastic Sierpinski gasket, on the basis of which we construct a network called random Sierpinski network (RSN). We investigate analytically or numerically the statistical characteristics of RSN. The obtained results reveal that the properties of RSN is particularly rich, it is simultaneously scale-free, small-world, uncorrelated

Maximilien Gadouleau, Zhiyuan Yan

Constant-dimension codes have recently received attention due to their significance to error control in noncoherent random network coding. In this paper, we show that constant-rank codes are closely related to constant-dimension codes and we study the properties of constant-rank codes. We first introduce a relation between vectors in $\mathrm{GF}(q^m)^n$ and

C. -J. Cheng, S. H. Lim, S. Fujino, W. R. McKenzie

We investigate the microstructural evolution in a ferroelectric to antiferroelectric phase transition at the morphotropic phase boundary in the Bi(1-x)SmxFeO3 system. Continuous Sm3+ substitution on the A-site induces short-range anti-parallel cation displacements as verified by the appearance of localized 1/4(110) weak spots in selected area electron diffra

Miodrag C. Iovanov

&#34;Co-Frobenius&#34; coalgebras were introduced as dualizations of Frobenius algebras. Recently, it was shown in \cite{I} that they admit left-right symmetric characterizations analogue to those of Frobenius algebras: a coalgebra $C$ is co-Frobenius if and only if it is isomorphic to its rational dual. We consider the more general quasi-co-Frobenius (QcF)

Guillermo A. Blanc, Paulina Lira, L. Felipe Barrientos, Paula Aguirre

We present K-band imaging of two ~30'x30' fields covered by the MUSYC Wide NIR Survey. The 1030 and 1255 fields were imaged with ISPI on the 4m Blanco telescope at CTIO to a 5 sigma point-source limiting depth of K~20 (Vega). Combining this data with the MUSYC Optical UBVRIz imaging, we created multi-band K-selected source catalogs for both fields. These cat

M. Pletyukhov, U. Zuelicke

We present a theoretical study of spin-3/2 hole transport through mesoscopic rings, based on the spherical Luttinger model. The quasi-one-dimensional ring is created in a symmetric two-dimensional quantum well by a singular-oscillator potential for the radial in-plane coordinate. The quantum-interference contribution to the two-terminal ring conductance exhi

The BaBar Collaboration, B. Aubert

The &#34;τ\to 3πην&#34; decay with the &#34;η\to γγ&#34; mode is studied using 384 fb^-1 of data collected by the BaBar detector. The branching fraction is measured to be (1.60+/-0.05+/-0.11)x10^-4. It is found that &#34;τ\to f1 πνto 3πην&#34; is the dominant decay mode with a branching fraction of (1.11+/-0.06+/-0.05)x10^-4. The first error on the branching

M. Amenomori

We have already reported the first result on the all-particle spectrum around the knee region based on data from 2000 November to 2001 October observed by the Tibet-III air-shower array. In this paper, we present an updated result using data set collected in the period from 2000 November through 2004 October in a wide range over 3 decades between $10^{14}$ e

Valerie R Coffman, James P. Sethna, Gerd Heber, Mu Liu

Are the cohesive laws of interfaces sufficient for modelling fracture in polycrystals using the cohesive zone model? We examine this question by comparing a fully atomistic simulation of a silicon polycrystal to a finite element simulation with a similar overall geometry. The cohesive laws used in the finite element simulation are measured atomistically. We

Sean Sather-Wagstaff, Tirdad Sharif, Diana White

We investigate the properties of categories of G_C-flat R-modules where C is a semidualizing module over a commutative noetherian ring R. We prove that the category of all G_C-flat R-modules is part of a weak AB-context, in the terminology of Hashimoto. In particular, this allows us to deduce the existence of certain Auslander-Buchweitz approximations for R-

V. Smolcic, E. Schinnerer, M. Scodeggio, P. Franzetti

We explore the properties of the submillijansky radio population at 20 cm by applying a newly developed optical color-based method to separate star forming (SF) from AGN galaxies at intermediate redshifts (z<1.3). Although optical rest-frame colors are used, our separation method is shown to be efficient, and not biased against dusty starburst galaxies. This

Walter A. Harrison

The electronic structure is found to be understandable in terms of free-atom term values and universal interorbital coupling parameters, since self-consistent tight-binding calculations indicate that Coulomb shifts of the d-state energies are small. Special-point averages over the bands are seen to be equivalent to treatment of local octahedral clusters. The

O. W. Greenberg

I review the main features of the color charge degree of freedom in particle physics, sketch the paradox in the early quark model that led to color, give a personal perspective on the discovery of color and describe the introduction of the gauge theory of color.

R. S. Bunch, S. K. Donaldson

We give some detailed numerical information about extremal metrics on four different toric surfaces. These are sample of many other cases which can be treated using a computer programme outlined in the paper.

R. Chatterjee, N. C. Panoiu, K. Liu, Z. Dios

We report the observation of imaging beyond the diffraction limit due to bound surface states in negative refraction photonic crystals. We achieve an effective negative index figure-of-merit [-Re(n)/Im(n)] of at least 380, ~125x improvement over recent efforts in the near-infrared, with a 0.4 THz bandwidth. Supported by numerical and theoretical analyses, th

Xufen Wu, Benoit Famaey, Gianfranco Gentile, Hagai Perets

We compute the Milky Way potential in different cold dark matter (CDM) based models, and compare these with the modified Newtonian dynamics (MOND) framework. We calculate the axis ratio of the potential in various models, and find that isopotentials are less spherical in MOND than in CDM potentials. As an application of these models, we predict the escape ve

Mladen Georgiev

We stress on the similarities between vibronic symmetry-breaking, due to the mixing of electronic states by phonons and leading to vibronic polarons along a helix, and the conceivable helical form of light propagation possibly arising from a symmetry breaking, due to the mixing of fermion states by photons.

T. Mori, E. J. Nicol, S. Shiizuka, K. Kuniyasu

New THz data on the optical conductivity of Pb are presented as well as a detailed Eliashberg analysis with particular emphasis on phonon-assisted processes not included in a BCS approach. Consideration of the optical self-energy instead of the conductivity itself helps highlight the differences with BCS predictions. Predicted coherence peaks are observed in

Daniela Dragoman

A phase space treatment of special relativity of quantum systems is developed. In this approach a quantum particle remains localized if subject to inertial transformations, the localization occurring in a finite phase space area. Unlike non-relativistic transformations, relativistic transformations generally distort the phase space distribution function, bei

V. S. Luchko, A. P. Petravchuk

We prove that a Lie nilpotent one-sided ideal of an associative ring $R$ is contained in a Lie solvable two-sided ideal of $R$. An estimation of derived length of such Lie solvable ideal is obtained depending on the class of Lie nilpotency of the Lie nilpotent one-sided ideal of $R.$ One-sided Lie nilpotent ideals contained in ideals generated by commutators

Hua Xu, Su Li, C. J. Lobb, Steven M. Anlage

We study dynamic fluctuation effects of $YBa_2Cu_3O_{7-δ}$ thin films in zero field around $T_c$ by doing frequency-dependent microwave conductivity measurements at different powers. The length scales probed in the experiments are varied systematically allowing us to analyze data which are not affected by the finite thickness of the films, and to observe sin

O. Argüello-Miranda, G. Sáenz-Arce

The topographic structure of Giemsa banded (G-banded) early metaphase human chromosomes adsorbed on glass was analyzed by atomic force microscope using amplitude modulation mode [AM-AFM]. Longitudinal height measurements for early metaphasic human chromosomes showed a central ridge that was further characterized by transversal height measurements. The hetero

Adilson E. Motter, Natali Gulbahce, Eivind Almaas, Albert-Laszlo Barabasi

An important goal of medical research is to develop methods to recover the loss of cellular function due to mutations and other defects. Many approaches based on gene therapy aim to repair the defective gene or to insert genes with compensatory function. Here, we propose an alternative, network-based strategy that aims to restore biological function by forci

Oleg I. Morozov

We derive two non-equivalent coverings for the r-th mdKP equation from Maurer--Cartan forms of its symmetry pseudo-group. Also we find Bäcklund transformations between the covering equations.

Alexey Pak, Andrzej Czarnecki

Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu are evaluated to the second order in the coupling constant, O(alpha_s^2), and to several orders in the expansion in quark masses, m_c/m_b. Corrections are calculated for the total decay rate as well as for the first two moments of the lepton energy and the hadron system energy distrib

Moises Venouziou, Gregory C. Verchota

R. M. Brown&#39;s theorem on mixed Dirichlet and Neumann boundary conditions is extended in two ways for the special case of polyhedral domains. A (1) more general partition of the boundary into Dirichlet and Neumann sets is used on (2) manifold boundaries that are not locally given as the graphs of functions. Examples are constructed to illustrate necessity

Michael Hahsler, Christian Buchta, Kurt Hornik

Mining association rules is a popular and well researched method for discovering interesting relations between variables in large databases. A practical problem is that at medium to low support values often a large number of frequent itemsets and an even larger number of association rules are found in a database. A widely used approach is to gradually increa

Alex E. Bernardini

We study the tunneling zone solutions of a one-dimensional electrostatic potential for the relativistic (Dirac to Klein-Gordon) wave equation when the incoming wave packet exhibits the possibility of being almost totally transmitted through the barrier. The transmission probabilities, the phase times and the dwell times for the proposed relativistic dynamics

Kirill Melnikov

We compute the next-to-next-to-leading order (NNLO) QCD corrections to b \to c l \bar ν_l decay rate at a fully differential level. Arbitrary cuts on kinematic variables of the decay products can be imposed. Our computation can be used to study the NNLO QCD corrections to the total decay rate as well as to the lepton energy, hadronic invariant mass and hadro

L. Gizon, M. Rempel

We present independent observations of the solar-cycle variation of flows near the solar surface and at a depth of about 60 Mm, in the latitude range $\pm45^\circ$. We show that the time-varying components of the meridional flow at these two depths have opposite sign, while the time-varying components of the zonal flow are in phase. This is in agreement with

V. V. Bel&#39;kov, S. D. Ganichev

Magneto-gyrotropic photogalvanic effects in quantum wells are reviewed. We discuss experimental data, results of phenomenological analysis and microscopic models of these effects. The current flow is driven by spin-dependent scattering in low-dimensional structures gyrotropic media resulted in asymmetry of photoexcitation and relaxation processes. Several ap

R. Spatschek, E. A. Brener, D. Pilipenko

We discuss steady state crack growth in the spirit of a free boundary problem. It turns out that mode I and mode III situations are very different from each other: In particular, mode III exhibits a pronounced transition towards unstable crack growth at higher driving forces, and the behavior close to the Griffith point is determined entirely through crack s

M. Gebran, R. Monier, O. Richard

Abundances of 18 chemical elements have been derived for 27 A/Am and 16 F stars members of the Pleiades and Coma Berenices open clusters. We have specifically computed, with the Montréal code, a series of evolutionary models for two A stars members of these two clusters. None of the models reproduces entirely the overall shape of the abundances patterns. The

W. A. Al-Saidi, C. J. Umrigar

Diffusion Monte Carlo (DMC) calculations are performed on the monocyclic and bicyclic forms of m-benzyne, which are the equilibrium structures at the CCSD(T) and CCSD levels of coupled cluster theory. We employed multi-configuration self-consistent field trial wave functions which are constructed from a carefully selected 8-electrons-in-8-orbitals complete a

A. B. Harris, M. Kenzelmann, Amnon Aharony, O. Entin-Wohlman

Starting from the irreducible representations of the group of the wave vector we construct the spin wave functions consistent with inversion symmetry, neglected in the usual representation analysis. We obtain the relation between the basis functions of different members of the star of the wave vector. We introduce order parameters and determine their transfo

Antonio N. Bernal, Miguel Sánchez, Francisco José Soler Gil

In a recent article, M. Tegmark poses the hypothesis that our known universe is a ``baggage free&#39;&#39; mathematical structure among many other possible ones, which also correspond to other physical universes --Mathematical Universe Hypothesis, MUH. Naturally, questions arise, such as how to obtain the physical properties of our world from the mathematica

Igor Bejenari, Valeriu Kantser

The asymptotic solution of the Schrodinger equation with non-separable variables is obtained for a particle confined to an infinite elliptic cylinder potential well under applied uniform longitudinal magnetic field. Using standard-problem method, dimension quantized eigenvalues have been calculated when the magnetic length is large enough in comparison with

P. F. Griffin, E. Riis, A. S. Arnold

We propose and numerically investigate a scalable ring trap for cold atoms that surmounts problems of roughness of the potential and end--effects of trap wires. A stable trapping potential is formed about an electrically isolated, conducting loop in an ac magnetic field by time averaging the superposition of the external and induced magnetic fields. We inves

Jure Leskovec, Eric Horvitz

We present a study of anonymized data capturing a month of high-level communication activities within the whole of the Microsoft Messenger instant-messaging system. We examine characteristics and patterns that emerge from the collective dynamics of large numbers of people, rather than the actions and characteristics of individuals. The dataset contains summa

Marcelino Agundez, Jose Cernicharo, Javier R. Goicoechea

We present time dependent chemical models for a dense and warm O-rich gas exposed to a strong far ultraviolet field aiming at exploring the formation of simple organic molecules in the inner regions of protoplanetary disks around T Tauri stars. An up-to-date chemical network is used to compute the evolution of molecular abundances. Reactions of H2 with small

David Krejcirik

We consider the Laplacian in a domain squeezed between two parallel curves in the plane, subject to Dirichlet boundary conditions on one of the curves and Neumann boundary conditions on the other. We derive two-term asymptotics for eigenvalues in the limit when the distance between the curves tends to zero. The asymptotics are uniform and local in the sense

Mark W. Paris

The dynamical coupled channel approach is applied to study the $ω$--meson production induced by pions and photons scattering from the proton. The parameters of the model are fixed in a two-channel (\on,\pn) calculation for the non-resonant and resonant contributions to the $T$ matrix by fitting the available unpolarized differential cross section data. The p

Murray Peshkin

It is tempting to try to explain the reported time-modulated decay rate in the GSI experiment by arguing that the matrix element for decay at any time results in an interference between two slightly different momentum values in the parent ion beam. I show here that a unitarity theorem of quantum mechanics rules out a wide class of such explanations.

J. Ricardo de Sousa, N. S. Branco

The phase diagram of the spin-1 Ising model in the presence of a biaxial crystal-field anisotropy is studied within the framework of a variational approach, based on the Bogolyubov inequality for the free energy. We have investigated the effects of a transverse crystal-field $D_{y}$ on the phase diagram in the $T-D_{x}$ plane. Results obtained by using effec

H. Kösters

We consider the asymptotic behaviour of the second-order correlation function of the characteristic polynomial of a real symmetric random matrix. Our main result is that the existing result for a random matrix from the Gaussian Orthogonal Ensemble essentially continues to hold for a general real symmetric Wigner matrix.

Lucia Scardia

A homogenization result is given for a material having brittle inclusions arranged in a periodic structure. According to the relation between the softness parameter and the size of the microstructure, three different limit models are deduced via Gamma-convergence. In particular, damage is obtained as limit of periodically distributed microfractures.

Lucia Scardia

We study the problem of the rigorous derivation of one-dimensional models for a thin curved beam starting from three-dimensional nonlinear elasticity. We describe the limiting models obtained for different scalings of the energy. In particular, we prove that the limit functional corresponding to higher scalings coincides with the one derived by dimension red

F. Götze, H. Kösters

We consider the asymptotics of the second-order correlation function of the characteristic polynomial of a random matrix. We show that the known result for a random matrix from the Gaussian Unitary Ensemble essentially continues to hold for a general Hermitian Wigner matrix. Our proofs rely on an explicit formula for the exponential generating function of th

Lucia Scardia

The problem of the rigorous derivation of one-dimensional models for nonlinearly elastic curved beams is studied in a variational setting. Considering different scalings of the three-dimensional energy and passing to the limit as the diameter of the beam goes to zero, a nonlinear model for strings and a bending-torsion theory for rods are deduced.

J. C. Barba, F. Finkel, A. Gonzalez-Lopez, M. A. Rodriguez

We compute the partition function of the su(m) Polychronakos-Frahm spin chain of BC_N type by means of the freezing trick. We use this partition function to study several statistical properties of the spectrum, which turn out to be analogous to those of other spin chains of Haldane-Shastry type. In particular, we find that when the number of particles is suf

Jose P. Palao, Ronnie Kosloff, Christiane P. Koch

Optimal control theory is developed for the task of obtaining a primary objective in a subspace of the Hilbert space while avoiding other subspaces of the Hilbert space. The primary objective can be a state-to-state transition or a unitary transformation. A new optimization functional is introduced which leads to monotonic convergence of the algorithm. This

J. Teschner

We discuss the problem to develop a mathematical theory of a certain class of nonrational conformal field theories (CFT) which contain the unitary CFT. A variant of the concept of a modular functor is proposed that appears to be suitable for such CFT.

N. S. Branco, J. Ricardo de Sousa, Angsula Ghosh

Using a real-space renormalization-group approximation, we study the anisotropic quantum Heisenberg model on hierarchical lattices, with interactions following aperiodic sequences. Three different sequences are considered, with relevant and irrelevant fluctuations, according to the Luck-Harris criterion. The phase diagram is discussed as a function of the an

Thibault Damour, Piotr Jaranowski, Gerhard Schäfer

Using a recent, novel Hamiltonian formulation of the gravitational interaction of spinning binaries, we extend the Effective One Body (EOB) description of the dynamics of two spinning black holes to next-to-leading order (NLO) in the spin-orbit interaction. The spin-dependent EOB Hamiltonian is constructed from four main ingredients: (i) a transformation bet

E. Shchukin, W. Vogel

Multipartite Bell-type inequalities are derived for general systems. They involve up to eight observables with arbitrary spectra on each site. These inequalities are closely related to the algebras of quaternions and octonions.

Maurice de Gosson, Franz Luef

We extend Hardy&#39;s uncertainty principle for a square integrable function and its Fourier transform to the multidimensional case using a symplectic diagonalization. We use this extension to show that Hardy&#39;s uncertainty principle is equivalent to a statement on the Wigner distribution of the function. We give a geometric interpretation of our results

Miroslav Dobšíček

In this thesis, attention is paid to small experimental testbed applications with respect to the quantum phase estimation algorithm, the core approach for finding energy eigenvalues. An iterative scheme for quantum phase estimation (IPEA) is derived from the Kitaev phase estimation, a study of robustness of the IPEA utilized as a few-qubit testbed applicatio

Darrin Speegle

The Feichtinger Conjecture, if true, would have as a corollary that for each set $E\subset \T$ and $Λ\subset \Z$, there is a partition $Λ_1,...,Λ_N$ of $\Z$ such that for each $1\le i \le N$, $\{\exp(2πi xλ): λ\in Λ_i\}$ is a Riesz sequence. In this paper, sufficient conditions on sets $E\subset \T$ and $Λ\subset \R$ are given so that $\{\exp(2πi xλ) 1_E: λ\

Brian P. Tighe, Adrianne R. T. van Eerd, Thijs J. H. Vlugt

A long-standing issue in the area of granular media is the tail of the force distribution, in particular whether this is exponential, Gaussian, or even some other form. Here we resolve the issue for the case of the force network ensemble in two dimensions. We demonstrate that conservation of the total area of a reciprocal tiling, a direct consequence of loca

Min Song

In this paper, we consider the perturbed renewal risk process. Systems of integro-differential equations for the Gerber-Shiu functions at ruin caused by a claim and oscillation are established, respectively. The explicit Laplase transforms of Gerber-Shiu functions are obtained, while the closed form expressions for the Gerber-Shiu functions are derived when

A. A. Coley, W. C. Lim, G. Leon

We use the 1+3 frame formalism to write down the evolution equations for spherically symmetric models as a well-posed system of first order PDEs in two variables, suitable for numerical and qualitative analysis.