March 2009 arXiv papers — page 47

Aushra Abouzeid, Bard Ermentrout

The phase-resetting curve (PRC) describes the response of a neural oscillator to small perturbations in membrane potential. Its usefulness for predicting the dynamics of weakly coupled deterministic networks has been well characterized. However, the inputs to real neurons may often be more accurately described as barrages of synaptic noise. Effective connect

Ko Sanders

We prove that the singularity structure of all n-point distributions of a state of a generalised real free scalar field in curved spacetime can be estimated if the two-point distribution is of Hadamard form. In particular this applies to the real free scalar field and the result has applications in perturbative quantum field theory, showing that the class of

J. Dobaczewski, W. Satula, B. G. Carlsson, J. Engel

We describe the new version (v2.38j) of the code HFODD which solves the nuclear Skyrme-Hartree-Fock or Skyrme-Hartree-Fock-Bogolyubov problem by using the Cartesian deformed harmonic-oscillator basis. In the new version, we have implemented: (i) projection on good angular momentum (for the Hartree-Fock states), (ii) calculation of the GCM kernels, (iii) calc

Emil Schwab

Categories of partial functions have become increasingly important principally because of their applications in theoretical computer science. In this note we prove that the category of partial bijections between sets as an inverse-Baer*-category with closed projections and in which the idempotent split is an exact category. Finally the Noether isomorphism th

F. Gafarov, N. Khusnutdinov, F. Galimyanov

It is currently accepted that cortical maps are dynamic constructions that are altered in response to external input. Experience-dependent structural changes in cortical microcurcuts lead to changes of activity, i.e. to changes in information encoded. Specific patterns of external stimulation can lead to creation of new synaptic connections between neurons.

Zaki Leghtas, Mazyar Mirrahimi, Pierre Rouchon

An observer-based Hamiltonian identification algorithm for quantum systems has been proposed recently by Bonnabel et al. The later paper provided a method to estimate the dipole moment matrix of a quantum system requiring the measurement of the populations on all states, which could be experimentally difficult to achieve. We propose here an extension to a 3-

T. A. Carroll, M. Kopf, K. G. Strassmeier, I. Ilyin

Zeeman-Doppler Imaging (ZDI) is a powerful inversion method to reconstruct stellar magnetic surface fields. The reconstruction process is usually solved by translating the inverse problem into a regularized least-square or optimization problem. In this contribution we will emphasize that ZDI is an inherent non-linear problem and the corresponding regularized

Youri Davydov, Shuyan Liu

Let $X$ be a random vector in $\rd$ with a regularly varying tail. We consider two transformations $\|X\|f(\frac{X}{\|X\|})$, $f: \sd\to\sd$, and $Xf(\frac{X}{\|X\|})$, $f: \sd\to \mathbb{R}_+$. Some sufficient conditions for preserving the property of regularity of the tail for this kind of transformations are given.

Feng Qi, Bai-Ni Guo

In this paper, some monotonicity and concavity results of several functions involving the psi and polygamma functions are proved, and then some known inequalities are extended and generalized.

Saquib Razak, Vinay Kolar, Nael B. Abu-Ghazaleh, Khaled A. Harras

In a Multi-hop Wireless Networks (MHWN), packets are routed between source and destination using a chain of intermediate nodes; chains are a fundamental communication structure in MHWNs whose behavior must be understood to enable building effective protocols. The behavior of chains is determined by a number of complex and interdependent processes that arise

Markus Kunze

We study continuity and equicontinuity of semigroups on norming dual pairs with respect to topologies defined in terms of the duality. In particular, we address the question whether continuity of a semigroup already implies (local/quasi) equicontinuity. We apply our results to transition semigroups and show that, under suitable hypothesis on $E$, every trans

MD Taylor

We give derivations of some basic results for the Bernstein approximation in $n$ variables that are useful in investigating copulas. It is shown that Bernstein approximations of copulas are again copulas. We exhibit a stochastic interpretation for the Bernstein approximation of a copula.

Ute Lisenfeld, Frederic Bournaud, Elias Brinks, Pierre-Alain Duc

Tidal Dwarf Galaxies (TDGs), produced from material expelled in galactic interactions, are well--suited to test the laws of star formation (SF) due to their simple structure, high metallicity -- making CO a reliable tracer of the molecular gas content -- and recent SF. Here, we study the conditions for the onset of SF and for the rate at which SF proceeds on

Ma Luo, Chengguang Bao, Zhibing Li

Dressed states of spinor Bose-Einstein condensates of spin-1 atoms coupling with optical cavity modes with far off resonance frequency are investigated. The exact solution of time evolution of population of spin component is derived, and the numerical result shows that the evolution is different from spin mixing without the coupling. Due to the coupling with

Xue-xiang Xu, Li-yun Hu, Hong-yi Fan

It is known that exp[i\lamda(Q_1P_1-i/2)] is a unitary single-mode squeezing operator, where Q_1,P_1 are the coordinate and momentum operators, respectively. In this paper we employ Dirac's coordinate representation to prove that the exponential operator S_{n}=Exp[i\lamda sum_{i=1}^{n}](Q_{i}P_{i+1}+Q_{i+1}P_{i}))], (Q_{n+1}=Q_1P_{n+1}=P_1), is a n-mode

Francesco Bonechi, Pavel Mnev, Maxim Zabzine

We describe a canonical reduction of AKSZ-BV theories to the cohomology of the source manifold. We get a finite dimensional BV theory that describes the contribution of the zero modes to the full QFT. Integration can be defined and correlators can be computed. As an illustration of the general construction we consider two dimensional Poisson sigma model and

J. Schlappa, C. F. Chang, E. Schierle, A. Tanaka

We studied the stripe phase of La1.8Sr0.2NiO4 using neutron diffraction, resonant soft x-ray diffraction (RSXD) at the Ni L2,3 edges, and resonant x-ray diffraction (RXD) at the Ni K threshold. Differences in the q-space resolution of the different techniques have to be taken into account for a proper evaluation of diffraction intensities associated with the

Fengzhong Wang, Shwu-Jane Shieh, Shlomo Havlin, H. Eugene Stanley

We investigate the two components of the total daily return (close-to-close), the overnight return (close-to-open) and the daytime return (open-to-close), as well as the corresponding volatilities of the 2215 NYSE stocks from 1988 to 2007. The tail distribution of the volatility, the long-term memory in the sequence, and the cross-correlation between differe

Jurgen Schaffner-Bielich, Irina Sagert, Matthias Hempel, Giuseppe Pagliara

The possible role of a first order QCD phase transition at nonvanishing quark chemical potential and temperature for cold neutron stars and for supernovae is delineated. For cold neutron stars, we use the NJL model with nonvanishing color superconducting pairing gaps, which describes the phase transition to the 2SC and the CFL quark matter phases at high bar

Markus Lazar

In this letter we discuss the Higgs mechanism in the linear and static translational gauge theory of dislocations. We investigate the role of the Nambu-Goldstone field and the Proca field in the dislocation gauge theory. In addition, we give the constitutive relations for (homogeneous) anisotropic, hemitropic and isotropic materials and also stress function

Martin W. Sorensen Anders S. Sorensen

We present a three-dimensional theory of stimulated Raman scattering (SRS) or superradiance. In particular we address how the spatial and temporal properties of the generated SRS beam, or Stokes beam, of radiation depends on the spatial properties of the gain medium. Maxwell equations for the Stokes field operators and of the atomic operators are solved anal

Wenjian Yu, Dirk Helbing

Game theory has been one of the most successful quantitative concepts to describe social interactions, their strategical aspects, and outcomes. Among the payoff matrix quantifying the result of a social interaction, the interaction conditions have been varied, such as the number of repeated interactions, the number of interaction partners, the possibility to

Giampiero Palatucci, Yannick Sire

We study the $Γ$-convergence of the following functional ($p>2$) $$ F_ε(u):=ε^{p-2}\int_Ω|Du|^p d(x,\partial Ω)^{a}dx+\frac{1}{ε^{\frac{p-2}{p-1}}}\int_ΩW(u) d(x,\partial Ω)^{-\frac{a}{p-1}}dx+\frac{1}{\sqrtε}\int_{\partialΩ}V(Tu)d\mathcal{H}^2, $$ where $Ω$ is an open bounded set of $\mathbb{R}^3$ and $W$ and $V$ are two non-negative continuous functions va

Efstratios Manousakis

When localized spins on different d orbitals prefer different types of antiferromagnetic ordering, the Hund's rule coupling creates frustration. Using spin-wave theory we study the case of two such orbitals on a square lattice coupled through Hund's rule, such that the first one couples antiferromagnetically (AF) more strongly to its nearest neighbor

V. A. Galaktionov

The fourth-order quasilinear reaction-diffusion equation with a p-Laplacian operator is shown to admit three types of blow-up. Self-similar patterns are first constructed for the regional blow-up case, where the rescaled problem admits a variational setting. Next, these were extended via a branching approach to non-variational problems.

M. A. Morales, E. Schwegler, D. M. Ceperley, C. Pierleoni

The properties of hydrogen-helium mixtures at Mbar pressures and intermediate temperatures (4000 to 10000 K) are calculated with first-principles molecular dynamics simulations. We determine the equation of state as a function of density, temperature, and composition and, using thermodynamic integration, we estimate the Gibbs free energy of mixing, thereby d

Predrag Jovanović, Luka Č. Popović

In this chapter we discuss the X-ray radiation from relativistic accretion disks around supermassive black holes, supposed to exist in the centers of Active Galactic Nuclei (AGN). Our focus is on the X-ray radiation, especially in the Fe K$α$ line which originates in the innermost parts of an accretion disk. Moreover, here we discuss some effects which can d

G. Thalhammer, G. Barontini, J. Catani, F. Rabatti

The route toward a Bose-Einstein condensate of dipolar molecules requires the ability to efficiently associate dimers of different chemical species and transfer them to the stable rovibrational ground state. Here, we report on recent spectroscopic measurements of two weakly bound molecular levels and newly observed narrow d-wave Feshbach resonances. The data

Henning Gast

This thesis deals with detector concepts aiming at a precise measurement of the cosmic-ray positron fraction extending to an as yet unreached range of energy. The indirect search for dark matter is the main motivation for this endeavour.

Ikuko Hamamoto, Ben R. Mottelson

The observed almost complete dominance of prolate over oblate deformations in the ground states of deformed even-even nuclei is related to the splitting of high $\ell$ "surface" orbits in the Nilsson diagram: on the oblate side the occurrence of numerous strongly avoided crossings which reduce the fanning out of the low $Λ$ orbits, while on the prola

Khee-Gan Lee, Kinwah Wu, Steven V. Fuerst, Graziella Branduardi-Raymont

We have calculated the relativistic reflection component of the X-ray spectra of accretion disks in active galactic nuclei (AGN). Our calculations have shown that the spectra can be significantly modified by the motion of the accretion flow and the gravity and rotation of the central black hole. The absorption edges in the spectra suffer severe energy shifts

T. Sedivcova-Uhlikova, Hewa Y. Abdullah, Nicola Manini

We introduce an accurate and efficient algebraic technique for the computation of the vibrational spectra of triatomic molecules, of both linear and bent equilibrium geometry. The full three-dimensional potential energy surface (PES), which can be based on entirely {\it ab initio} data, is parameterized as a product Morse-cosine expansion, expressed in bond-

Richard Buscall

Strong particulate gels are widely believed to behave poroelastically in compression, e.g. in sedimentation, even though they consolidate irreversibly because of the stickiness of the particles. Particulate gels are usually adhesive as well as cohesive and so wall effects are to be expected in general [Michaels & Bolger (1962)]. These are rarely manifest on

Azeem Mir, Farida Tahir Kamaluddin Ahmed

We study the decay rate of process B->K l+ l- (l=e,mu) and some of its other related observables, like forward backward asymmetry (A_{FB}), polarization asymmetry (PA) and CP-asymmetry (A_{CP}) in R-parity violating (R_{p}) Minimal Supersymmetric Standard Model (MSSM). The analysis shows that R_{p}Yukawa coupling products contribute significantly to the bran

J. Fink, S. Thirupathaiah, R. Ovsyannikov, H. A. Duerr

We report high resolution angle-resolved photoemission spectroscopy (ARPES) studies of the electronic structure of BaFe$_2$As$_2$, which is one of the parent compounds of the Fe-pnictide superconductors. ARPES measurements have been performed at 20 K and 300 K, corresponding to the orthorhombic antiferromagnetic phase and the tetragonal paramagnetic phase, r

J. Robrade, J. H. M. M. Schmitt

The A7 star Altair is one of the hottest magnetically active stars. Its proximity to the Sun allows a detailed investigation of a corona in X-rays for a star with a shallow convection zone. We used a deep XMM-Newton observation of Altair and analyzed X-ray light curves, spectra, and emission lines, investigated the temporal behavior and properties of the X-r

H. Ibrahim, M. Jazar, R. Monneau

We study a coupled system of two parabolic equations in one space dimension. This system is singular because of the presence of one term with the inverse of the gradient of the solution. Our system describes an approximate model of the dynamics of dislocation densities in a bounded channel submitted to an exterior applied stress. The system of equations is w

G. V. Dedkov, A. A. Kyasov

We review the fluctuation electromagnetic theory of attraction, friction and heating of neutral nonmagnetic nanoparticles moving with constant velocity in close vicinity to the solid surface. The theory is based on an exact solution of the relativistic problem of the fluctuation electromagnetic interaction in configuration sphere -plane in the dipole approxi

Leonard Mada

To asses the advantages of a computerized surveillance system to detect Healthcare-Associated Infections (HAI). All HAI reported to the Timis County branch of the Romanian National Health Insurance and the Public Health Authority during the year 2007 were collected and assessed for validity

Georgiana Petruta Fintineanu

The present study aims to emphasize the way in which the TELNET protocol for directing the mobile terminals is used and works. The paper is structured in three parts: the first two parts are a theoretic presentation of the TELNET protocol, respectively of the mobile terminals. The third part contains an application of the way in which a mobile terminal can b

Hongbo Lv, Shunhua Zhang

Let $A$ be a finite dimensional hereditary algebra over an algebraically closed field $k$, $A^{(m)}$ be the $m$-replicated algebra of $A$ and $\mathscr{C}_{m}(A)$ be the $m$-cluster category of $ A$. We investigate properties of complements to a faithful almost complete tilting $A^{(m)}$-module and prove that the $m$-cluster mutation in $\mathscr{C}_{m}(A)$

Lluis Torner, Yaroslav V. Kartashov

We address the concept of three-dimensional light bullet formation in structures where nonlinearity and dispersion are contributed by different materials, including metamaterials, which are used at their best to create suitable conditions where bullets can form. The particular geometry considered here consists of alternating rings made of highly dispersive b

Gyula Fodor, Péter Forgács, Zalán Horváth, Márk Mezei

The radiation loss of small-amplitude radially symmetric oscillons (long-living, spatially localized, time-dependent solutions) in two- and three-dimensional scalar field theories is computed analytically in the small-amplitude expansion. The amplitude of the radiation is beyond all orders in perturbation theory and it is determined using matched asymptotic

V. V. Gotsulenko, L. A. Gaponova, P. I. Kogut

For movements of the viscous continuous flow in generalized Couette cell the dynamic system describing the central limiting variety is received.

C. Clack, I. Ballai

The nonlinear theory of driven magnetohydrodynamics (MHD) waves in strongly anisotropic and dispersive plasmas, developed for slow resonance by Clack and Ballai [Phys. Plasmas, 15, 2310 (2008)] and Alfvén resonance by Clack \emph{et al.} [A&A,494, 317 (2009)], is used to study the weakly nonlinear interaction of fast magnetoacoustic (FMA) waves in a one-dime

Thomas Reiter

In the very near future the first data from LHC will be available. The searches for the Higgs boson and for new physics will require precise predictions both for the signal and the background processes. Tree level calculations typically suffer from large renormalization scale uncertainties. I present an efficient implementation of an algorithm for the automa

Zhi-Hui Wang, Bing-Shen Wang, Zhao-Bin Su

For an electron spin in coupling with an interacting spin chain via hyperfine-type interaction, we investigate the dynamical evolutions of the pairwise entanglement of the spin chain and a correlation function joined the electron spin with a pair of chain spins in correspondence to the electron spin coherence evolution. Both quantities manifest a periodic an

A. Rossani, A. M. Scarfone

The linear Boltzmann equation for elastic and/or inelastic scattering is applied to derive the distribution function of a spatially homogeneous system of charged particles spreading in a host medium of two-level atoms and subjected to external electric and/or magnetic fields. We construct a Fokker-Planck approximation to the kinetic equations and derive the

Bernhelm Booss-Bavnbek

We recall major findings of a systematic investigation of the mathematization of the individual sciences, conducted by the author in Bielefeld some 35 years ago under the direction of Klaus Krickeberg, and confront them with recent developments in physics, medicine, economics, and spectral geometry.

Isaac A. García, Maite Grau

The relation between limit cycles of planar differential systems and the inverse integrating factor was first shown in an article of Giacomini, Llibre and Viano appeared in 1996. From that moment on, many research articles are devoted to the study of the properties of the inverse integrating factor and its relation with limit cycles and their bifurcations. T

Francesco Toppan, Piet W. Verbeek

In this paper we address the problem of constructing a class of representations of Clifford algebras that can be named "alphabetic (re)presentations". The Clifford algebras generators are expressed as m-letter words written with a 3-character or a 4-character alphabet. We formulate the problem of the alphabetic presentations, deriving the main properties and

Nathann Cohen, Fedor V. Fomin, Gregory Gutin, Eun Jung Kim

An out-tree $T$ is an oriented tree with only one vertex of in-degree zero. A vertex $x$ of $T$ is internal if its out-degree is positive. We design randomized and deterministic algorithms for deciding whether an input digraph contains a given out-tree with $k$ vertices. The algorithms are of runtime $O^*(5.704^k)$ and $O^*(5.704^{k(1+o(1))})$, respectively.

Vladimir I. Man'ko, Alexandr A. Sergeevich

The known Peres-Horodecki criterion and scaling criterion of separability are considered on examples of three-mode and four-mode Gaussian states of electromagnetic field. It is shown that the principal minors of the photon quadrature dispersion matrix are sensitive to the change of scaling parameters. An empirical observation has shown that the bigger the mo

Nicola M. Pugno

In this paper we solve the multiple peeling problem by applying a fracture mechanics approach to a complex system of films, adhering to the substrate and having a common hinge, where the pulling force is applied. The simplest V-shaped system, consisting of two identical peeling tapes is considered as a case study (to be solved coupling six nonlinear equation

J. L. Karr, P Manoj, N Ohashi

High mass star formation and the evolution of HII regions have a substantial impact on the morphology and star formation history of molecular clouds. The HII region Gum 48d, located in the Centaurus Arm at a distance of 3.5 kpc, is an old, well evolved HII region whose ionizing stars have moved off the main sequence. As such, it represents a phase in the evo

David S. Dean, Ajay Gopinathan

While techniques to compute thermal fluctuation induced, or pseudo-Casimir, forces in equilibrium systems are well established, the same is not true for non-equilibrium cases. We present a general formalism that allows us to unambiguously compute non-equilibrium fluctuation induced forces by specifying the energy of interaction of the fluctuating fields with

M. Gavilan, M. Molla, A. I. Diaz

We have developed a grid of chemical evolution models applied to dwarf isolated galaxies, using \cite{gav05} yields. The input data enclose different star formation efficiencies, galaxy mass and collapse time values. The result is a wide collection of solutions that vary from objects with low metallicity and great amount of gas, to those with little gas and

David Kyed

We prove a Kunneth formula computing the Connes-Shlyakhtenko L^2-Betti numbers of the algebraic tensor product of two tracial *-algebras in terms of the L^2-Betti numbers of the two original algebras. As an application, we construct examples of non-finite, non-cocommutative, compact quantum groups with a non-vanishing first L^2-Betti number.

Benjamin M. Friedrich, Frank Jülicher

Chemotaxis along helical paths towards a target releasing a chemoattractant is found in sperm cells and many microorganisms. We discuss the stochastic differential geometry of the noisy helical swimming path of a chiral swimmer. A chiral swimmer equipped with a simple feedback system can navigate in a concentration gradient of chemoattractant. We derive an e

Dirk Helbing, Martin Treiber, Arne Kesting, Martin Schönhof

Starting from the instability diagram of a traffic flow model, we derive conditions for the occurrence of congested traffic states, their appearance, their spreading in space and time, and the related increase in travel times. We discuss the terminology of traffic phases and give empirical evidence for the existence of a phase diagram of traffic states. In c

Dirk Helbing

A local agglomeration of cooperators can support the survival or spreading of cooperation, even when cooperation is predicted to die out according to the replicator equation, which is often used in evolutionary game theory to study the spreading and disappearance of strategies. In this paper, it is shown that success-driven motion can trigger such local aggl

Simone Taioli, Stefano Simonucci, Lucia Calliari, Massimiliano Filippi

A mixed quantum mechanical and Monte Carlo method for calculating Auger spectra from nanoclusters is presented. The approach, based on a cluster method, consists of two steps. Ab initio quantum mechanical calculations are first performed to obtain accurate energy and probability distributions of the generated Auger electrons. In a second step, using the calc

Dirk Helbing, Amin Mazloumian

The efficiency of traffic flows in urban areas is known to crucially depend on signal operation. Here, elements of signal control are discussed, based on the minimization of overall travel times or vehicle queues. Interestingly, we find different operation regimes, some of which involve a "slower-is-faster effect", where a delayed switching reduces t

S. Sykora, K. W. Becker

Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors, leading to an unprecedented high transition temperature $T_c$, is still lacking. Starting from the $t$-$J$ model, we present a microscopic approach to the physical properties of the superconducting phase

Xiangwei Chu, Zhongzhi Zhang, Jihong Guan, Shuigeng Zhou

In this paper, we investigate the epidemic spreading for SIR model in weighted scale-free networks with nonlinear infectivity, where the transmission rate in our analytical model is weighted. Concretely, we introduce the infectivity exponent $α$ and the weight exponent $β$ into the analytical SIR model, then examine the combination effects of $α$ and $β$ on

Morbidelli Alessandro, Harold F. Levison, William Bottke, Luke Dones

By examining the absolute magnitude (H) distributions (hereafter HD) of the cold and hot populations in the Kuiper belt and of the Trojans of Jupiter, we find evidence that the Trojans have been captured from the outer part of the primordial trans-Neptunian planetesimal disk. We develop a sketch model of the HDs in the inner and outer parts of the disk that

Yasuhiko Shinno, Hiroshi Yoneyama

Two-color finite density QCD is free from the sign problem, and it is thus regarded as a good model to check the validity of the analytic continuation method. We study the method in terms of the corresponding chiral random matrix model. It is found that at temperatures slightly higher than the pseudo critical temperature, the ratio type of extrapolated funct

S. Sykora, K. W. Becker

Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors is still lacking. An additional puzzle is the unknown connection between the superconducting gap and the so-called pseudogap which is a central property of the most unusual normal state. Angle-resolved pho

Fatima Aboud, Didier Robert

In this paper we consider generalized eigenvalue problems for a family of operators with a quadratic dependence on a complex parameter. Our model is $L(λ)=-\triangle +(P(x)-λ)^2$ in $L^2(\R^d)$ where $P$ is a positive elliptic polynomial in $\R^d$ of degree $m\geq 2$. It is known that for $d$ even, or $d=1$, or $d=3$ and $m\geq 6$, there exist $λ\in\C$ and $

Freddy Munoz, Benoit Baudry

Dynamically Adaptive Systems (DAS) are systems that modify their behavior and structure in response to changes in their surrounding environment. Critical mission systems increasingly incorporate adaptation and response to the environment; examples include disaster relief and space exploration systems. These systems can be decomposed in two parts: the adaptat

Anatoli Iouditski, Arkadii S. Nemirovski

We consider the problem of recovering of continuous multi-dimensional functions from the noisy observations over the regular grid. Our focus is at the adaptive estimation in the case when the function can be well recovered using a linear filter, which can depend on the unknown function itself. In the companion paper "Nonparametric Denoising of Signals wi

Lucas Vienne

Let X be a non-empty finite set, E be a finite dimensional euclidean vector space and G a finite subgroup of O(E), the orthognal group of E. Suppose GG={U_i | i in X} is a finite set of linear lines in E and an orbit of G on which its operation is twice transitive. Then GG is an equiangular set of lines, which means that we can find a real number "c"

Ying Jiao

We apply the zero bias transformation to deduce a recursive asymptotic expansion formula for expectation of functions of sum of independent random variables in terms of normal expectations and we discuss the remainder term estimations.

Ying Jiao, Huyen Pham

We consider a financial market with a stock exposed to a counterparty risk inducing a drop in the price, and which can still be traded after this default time. We use a default-density modeling approach, and address in this incomplete market context the expected utility maximization from terminal wealth. We show how this problem can be suitably decomposed in

Samuel Walsh

This paper considers two-dimensional stably stratified steady periodic gravity water waves with surface profiles monotonic between crests and troughs. We provide sufficient conditions under which such waves are necessarily symmetric. This is done by first exploiting some elliptic structure in the governing equations to show that, in certain size regimes, a m

George W. Patrick, Raymond J. Spiteri, William Zhang, Charles Cuell

In the formalism of constrained mechanics, such as that which underlies the SHAKE and RATTLE methods of molecular dynamics, we present an algorithm to convert any one-step integration method to a variational integrator of the same order. The one-step method is arbitrary, and the conversion can be automated, resulting in a powerful and flexible approach to th

James Aguirre, Alexandre Amblard, Amjad Ashoorioon, Carlo Baccigalupi

How did the universe evolve? The fine angular scale (l>1000) temperature and polarization anisotropies in the CMB are a Rosetta stone for understanding the evolution of the universe. Through detailed measurements one may address everything from the physics of the birth of the universe to the history of star formation and the process by which galaxies formed.

The BES Collaboration, M. Ablikim

Using a data sample with a total integrated luminosity of 10.0 pb$^{-1}$ collected at center-of-mass energies of 2.6, 3.07 and 3.65 GeV with BESII, cross sections for $e^+e^-$ annihilation into hadronic final states ($R$ values) are measured with statistical errors that are smaller than 1%, and systematic errors that are about 3.5%. The running strong intera

Boris Kayser

We explain the relationship between Majorana neutrinos, which are their own antiparticles, and Majorana neutrino masses. We point out that Majorana masses would make the neutrinos very distinctive particles, and explain why many theorists strongly suspect that neutrinos do have Majorana masses. The promising approach to confirming this suspicion is to seek n

Sergey Kitaev, Jeffrey Remmel

Motivated by study of Mahonian statistics, in 2000, Babson and Steingrimsson introduced the notion of a "generalized permutation pattern" (GP) which generalizes the concept of "classical" permutation pattern introduced by Knuth in 1969. The invention of GPs led to a large number of publications related to properties of these patterns in permu

Balazs Szegedy

Ergodic theory, Higher order Fourier analysis and the hyper graph regularity method are three possible approaches to Szemerédi type theorems in abelian groups. In this paper we develop an algebraic theory that creates a connection between these approaches. Our main method is to take the ultra product of abelian groups and to develop a precise algebraic theor

Paolo Ventura, Francesca D'Antona

Context: We present the physical and chemical properties of intermediate-mass stars models of low metallicity, evolved along the thermal pulse phase. Aims: The target of this work is to extend to low metallicities, Z=1,2 and 6 x 10^{-4}, the models previously computed for chemistries typical of Globular Clusters of an intermediate metallicity (Z=0.001), and

Baocheng Zhang, Qing-yu Cai, Li You, M S Zhan

Using standard statistical method, we discover the existence of correlations among Hawking radiations (of tunneled particles) from a black hole. The information carried by such correlations is quantified by mutual information between sequential emissions. Through a careful counting of the entropy taken out by the emitted particles, we show that the black hol

L. A. Bokut, Yuqun Chen, Guangliang Zhang

In this paper, we study the concept of associative $n$-conformal algebra over a field of characteristic 0 and establish Composition-Diamond lemma for a free associative $n$-conformal algebra. As an application, we construct Gröbner-Shirshov bases for Lie $n$-conformal algebras presented by generators and defining relations.

Pai-Yi Hsiao, Zhuo-Han Tsai, Jia-Hong Huang, Ge-Ping Yu

We investigate the hetero-epitaxial growth of thin film deposited on a (001) substrate via molecular dynamics simulations, using six fcc transition metals as our modeling systems. By studying the radial distribution function in the film layers, we demonstrate the importance of the sign of lattice mismatch on the layer structure. For positive lattice mismatch

M. A. Cordiner T. J. Millar

A new chemical model is presented for the carbon-rich circumstellar envelope of the AGB star IRC+10216. The model includes shells of matter with densities that are enhanced relative to the surrounding circumstellar medium. The chemical model uses an updated reaction network including reactions from the RATE06 database and a more detailed anion chemistry. In

David Doty, Matthew J. Patitz

We introduce a domain-specific language (DSL) for creating sets of tile types for simulations of the abstract Tile Assembly Model. The language defines objects known as tile templates, which represent related groups of tiles, and a small number of basic operations on tile templates that help to eliminate the error-prone drudgery of enumerating such tile type

Feng Qi, Bai-Ni Guo

In the note, the functions $\abs{ψ^{(i)}(e^x)}$ for $i\in\mathbb{N}$ are proved to be sub-additive on $(\lnθ_i,\infty)$ and super-additive on $(-\infty,\lnθ_i)$, where $θ_i\in(0,1)$ is the unique root of equation $2\abs{ψ^{(i)}(θ)}=\abs{ψ^{(i)}(θ^2)}$.

María Montero-Castaño, Robeson M. Herrnstein, Paul T. P. Ho

We present the first large-scale mosaic performed with the Submillimeter Array (SMA) in the Galactic center. We have produced a 25-pointing mosaic, covering a ~2' x 2' area around Sgr A*. We have detected emission from two high-density molecular tracers, HCN(4-3) and CS(7-6), the latter never before reported in this region. The data have an angular r

Jose E. Juknevich, Dmitry Melnikov, Matthew J. Strassler

It is possible that the standard model is coupled, through new massive charged or colored particles, to a hidden sector whose low energy dynamics is controlled by a pure Yang-Mills theory, with no light matter. Such a sector would have numerous metastable "hidden glueballs" built from the hidden gluons. These states would decay to particles of the st

M R Setare, J Sadeghi, A R Amani

In this paper we study the tachyon cosmology in non-interacting and interacting cases in non-flat FRW universe. Then we reconstruct the potential and the dynamics of the tachyon field which describe tachyon cosmology.

Oscar F. Bandtlow, Cho-Ho Chu

Let $Ω$ be an open set in $\R^d$ $(d > 1)$ and $h(Ω)$ the Fréchet space of harmonic functions on $Ω$. Given a bounded linear operator $L :h(Ω)\to h(Ω)$, we show that its eigenvalues $λ_n$, arranged in decreasing order and counting multiplicities, satisfy $|λ_n|\leq K\exp(-cn^{1/(d-1)})$, where $K$ and $c$ are two explicitly computable positive constants.

Kenneth W. Desmond, Eric R. Weeks

Studies of random close packing of spheres have advanced our knowledge about the structure of systems such as liquids, glasses, emulsions, granular media, and amorphous solids. When these systems are confined their structural properties change. To understand these changes we study random close packing in finite-sized confined systems, in both two and three d

George W. Patrick, Charles Cuell

A complete error analysis of variational integrators is obtained, by blowing up the discrete variational principles, all of which have a singularity at zero time-step. Divisions by the time step lead to an order that is one less than observed in simulations, a deficit that is repaired with the help of a new past-future symmetry.

J. A. Gonzalez, F. S. Guzman

Using numerical methods we present the first full nonlinear study of phantom scalar field accreted into a black hole. We study different initial configurations and find that the accretion of the field into the black hole can reduce its area down to 50 percent within time scales of the order of few masses of the initial horizon. The analysis includes the case

YunPing Jiang, Yuan-Ling Ye

The Ruelle operator theorem has been studied extensively both in dynamical systems and iterated function systems. In this paper we study the Ruelle operator theorem for nonexpansive systems. Our theorems give some sufficient conditions for the Ruelle operator theorem to be held for a nonexpansive system.

Rishi Khatri, Benjamin D. Wandelt

Inhomogeneous recombination can give rise to perturbations in the electron number density which can be a factor of five larger than the perturbations in baryon density. We do a thorough analysis of the second order anisotropies generated in the cosmic microwave background (CMB) due to perturbations in the electron number density. We show that solving the sec

Mark Pankov

Results are well-known

Dimitrie Culcer, Lukasz Cywinski, Qiuzi Li, Xuedong Hu

There has been significant progress in the implementation and manipulation of singlet-triplet qubits in GaAs quantum dots. Given the considerably longer spin coherence times measured in Si, considerable interest has been generated recently in Si quantum dots. The physics of these systems is considerably more complex than the physics of GaAs quantum dots owin

Yin Lin

If lepton masses and mixings are explained by a flavour symmetry in seesaw model which leads to U_{e3}=0 at leading order, we find that, under reasonable assumptions, a future observation of low energy leptonic CP violation implies, barring accidental cancellations, a lepton asymmetry both in flavoured leptogenesis and in its one-flavour approximation. We ex