October 2010 arXiv papers — page 40

A. S. de Castro

A simple formalism for exploring quantum scattering and possible bound states in an arbitrary symmetric and localized potential in a unified way is presented. The symmetric square barrier and well potentials are used for illustrating the method.

M. V. Chizhov, V. A. Bednyakov, J. A. Budagov

With this note we would like to draw attention to a possible novel signal of new physics in dijet data at the hadron colliders. Usually it is accepted that all exotic models predict that these two jets populate the central (pseudo)rapidity region where y_{1,2} ~ 0. Contrary, the excited bosons do not contribute into this region, but produce an excess of dije

D. Semikoz

In these three lectures I discuss the present status of high-energy astroparticle physics including Ultra-High-Energy Cosmic Rays (UHECR), high-energy gamma rays, and neutrinos. The first lecture is devoted to ultra-high-energy cosmic rays. After a brief introduction to UHECR I discuss the acceleration of charged particles to highest energies in the astrophy

Fengping Jin, Hans De Raedt, Shengjun Yuan, Mikhail I. Katsnelson

We study the time evolution of the reduced density matrix of a system of spin-1/2 particles interacting with an environment of spin-1/2 particles. The initial state of the composite system is taken to be a product state of a pure state of the system and a pure state of the environment. The latter pure state is prepared such that it represents the environment

Oliver Muelken, Maximilian Bauer

We study the coherent dynamics of excitations on vibrating chains. By applying an external field and matching the field strength with the oscillation frequency of the chain it is possible to obtain an (average) transport of an initial Gaussian wave packet. We distinguish between a uniform oscillation of all nodes of the chain and the chain being in its lowes

Daniel Sebastian, Eike W. Guenther

Up to now, planet search programs have concentrated on main sequence stars later than spectral type F5. However, identifying planets of early type stars would be interesting. For example, the mass loss of planets orbiting early and late type stars is different because of the differences of the EUV and X-ray radiation of the host stars. As an initial step, we

R. K. Mandal

A four dimensional description for the trigonal phase is presented. It has been demonstrated that it is possible to model one dimensional quasiperiodic structure with trigonal symmetry apart from recovering the Miller-Bravais scheme for the description of hexagonal phases. A similar discussion on the two classes of decagonal phases having 10/m and 105 symmet

J. M. F. Bassalo, P. T. S. Alencar, D. G. da Silva, A. B. Nassar

In this paper we study the quantum wave packet and the Feynman-de Broglie-Bohm propagator of the linearized Schuch-Chung-Hartmann equation along a classical trajetory.

Daniel Krefl, Johannes Walcher

We have recently shown that the global behavior of the partition function of N=2 gauge theory in the general Omega-background is captured by special geometry in the guise of the (extended) holomorphic anomaly equation. We here analyze the fate of our results under the shift of the mass parameters of the gauge theory. The preferred value of the shift, noted p

Raj Kumar Pan, Sitabhra Sinha

Are there general principles governing the process by which certain products or ideas become popular relative to other (often qualitatively similar) competitors? To investigate this question in detail, we have focused on the popularity of movies as measured by their box-office income. We observe that the log-normal distribution describes well the tail (corre

R. Fiore, V. R. Zoller

The overall hardness scale of the ultra-high energy neutrino-nucleon interactions is usually estimated as $Q^2\sim m_W^2$. The effect of non-conservation of weak currents pushes this scale up to the top quark mass squared and changes dynamics of the scattering process. The Double Leading Log Approximation provides simple and numerically accurate formula for

Ali Goker, Zhiyong Zhu, Udo Schwingenschlogl

The time-dependent non-crossing approximation is utilized to determine the effects of the crystal planes of gold contacts on time dependent current through a quantum dot suddenly shifted into the Kondo regime via a gate voltage. For an asymmetrically coupled system, instantaneous conductance exhibits complex fluctuations. We identify the frequencies particip

J. M. Brader, M. Krüger

Using a dynamical density functional theory we analyze the density profile of a colloidal liquid near a wall under shear flow. Due to the symmetries of the system considered, the naive application of dynamical density functional theory does not lead to a shear induced modification of the equilibrium density profile, which would be expected on physical ground

Younes Ezzahri, Karl Joulain, Ali Shakouri

A recently developed Shastry's formalism for energy transport is used to analyze the temporal and spatial behaviors of the energy and heat transport in metals under delta function excitation at the surface. Comparison with Cattaneo's model is performed. Both models show the transition between nonthermal (ballistic) and thermal (ballistic-diffusive) r

Irina Rychkova, Valentin Rychkov, Kyryl Kazymyrenko, Simone Borlenghi

This paper is the documentation for a numerical code for quantum transport called KNIT. The KNIT library implements a generalization of the well known recursive Green function technique for a large class of multi-terminal mesoscopic systems with arbitrary geometries, topology and dimension. The systems are described by tight-biding Hamiltonians (with arbitra

R. Rodriguez-Guzman, P. Sarriguren, L. M. Robledo

The systematics of one-quasiparticle configurations in neutron-rich Sr, Zr, and Mo odd isotopes is studied within the Hartree-Fock-Bogoliubov plus Equal Filling Approximation method preserving both axial and time reversal symmetries. Calculations based on the Gogny energy density functional with both the standard D1S parametrization and the new D1M incarnati

I. R. Shein, A. N. Enyashin, A. L. Ivanovskii

The atomic models of nanotubes for layered FeSe, LiFeAs, SrFe2As2, and LnFeAsO - the parent phases of so-called 11, 111, 122, and 1111 groups of newly discovered family of iron-based high temperature superconductors are proposed. On example of SrFe2As2 the electronic properties of predicted nanotubes are examined and discussed in comparison with those for th

Ana Charpentier, Caroline Fontaine, Teddy Furon, Ingemar Cox

Tardos codes are currently the state-of-the-art in the design of practical collusion-resistant fingerprinting codes. Tardos codes rely on a secret vector drawn from a publicly known probability distribution in order to generate each Buyer's fingerprint. For security purposes, this secret vector must not be revealed to the Buyers. To prevent an untrustwor

Michele Campisi, David Zueco, Peter Talkner

The exactly solvable model of a one dimensional isotropic XY spin chain is employed to study the thermodynamics of open systems. For this purpose the chain is subdivided into two parts, one part is considered as the system while the rest as the environment or bath. The equilibrium properties of the system display several anomalous aspects such as negative en

Xavier Dumusque, Stephane Udry, Christophe Lovis, Nuno C. Santos

The radial velocity signature of stellar noise is small, around the meter-per-second, but already too much for the detection of Earth mass planets in habitable zones. In this paper, we address the important role played by observational strategies in averaging out the radial velocity signature of stellar noise. We also derive the planetary mass detection limi

Dainis Zeps

We consider combinatorial maps with fixed combinatorial knot numbered with augmenting numeration called normalized knot. We show that knot's normalization doesn't affect combinatorial map what concerns its generality. Knot's normalization leads to more concise numeration of corners in maps, e.g., odd or even corners allow easy to follow distingui

E. Peinado

The study of an extension of the standard model based on the flavor symmetry A4 is presented. Neutrino Majorana mass terms arise from dimension five operator and charged lepton masses from renormalizable Yukawa couplings. We introduce three Higgs doublets that belong to one triplet irreducible representation of A4. We study the most general A4-invariant scal

Kamran Mohseni

The divergence theorem of Gauss plays a central role in the derivation of the governing differential equations in fluid dynamics, electrodynamics, gravitational fields, and optics. One is often interested in an evolution equation for the large scale quantities without resolving the details of the small scales. As a result, there has been a significant effort

Keyvan Piroird, Baptiste Darbois Texier, Christophe Clanet, David Quéré

We present a fluid dynamics video showing the behavior of drops of liquid oxygen, at room temperature. Due to their low boiling point, these drops levitate on a cushion of their own vapour. This property gives them a high mobility, as known more generally in such Leidenfrost situations. But liquid oxygen is also paramagnetic, and thus likely to be manipulate

O. Coussy, Jean-Michel Pereira

Constitutive equations of unsaturated soils are often derived in a thermodynamically consistent framework through the use a unique 'effective' interstitial pressure. This later is naturally chosen as the space averaged interstitial pressure. However, experimental observations have revealed that two stress state variables were needed to describe the s

Jean-Michel Pereira, Olivier Coussy, Eduardo E. Alonso, Jean Vaunat

In unsaturated soil mechanics, the quest for an effective stress playing the same role as Terzaghi's effective stress does for saturated soils has introduced a long standing debate, dating back to the 1960s. Several contributions have been proposed since the early work of Bishop. It is well recognized to date that a single constitutive stress is not suff

Chiara Camere

Let X be a holomorphic symplectic fourfold such that b_2=23 and i a symplectic involution of X . The fixed locus F of i is a smooth symplectic submanifold of X; we show that F contains at least 12 isolated points and 1 smooth surface. We conjecture that F is made of 28 isolated fixed points and 1 K3 surface and we provide evidences for the conjecture in some

Stefko Miklavic, Paul Terwilliger

Let $D$ denote a positive integer and let $Q_D$ denote the graph of the $D$-dimensional hypercube. Let $X$ denote the vertex set of $Q_D$ and let $A \in \MX$ denote the adjacency matrix of $Q_D$. A matrix $B \in \MX$ is called $A$-{\em like} whenever both (i) $BA = AB$; (ii) for all $x,y \in X$ that are not equal or adjacent, the $(x,y)$-entry of $B$ is zero

Avi Gozolchiani, Kazuko Yamasaki, Shlomo Havlin

We construct and analyze a climate network which represents the interdependent structure of the climate in different geographical zones and find that the network responds in a unique way to El-Niño events. Analyzing the dynamics of the climate network shows that when El-Niño events begin, the El-Niño basin partially loses its influence on its surroundings. A

Andrea Asperti, Claudio Sacerdoti Coen, Enrico Tassi

We introduce a new technique for constructing a finite state deterministic automaton from a regular expression, based on the idea of marking a suitable set of positions inside the expression, intuitively representing the possible points reached after the processing of an initial prefix of the input string. Pointed regular expressions join the elegance and th

A. Lapi, A. Cavaliere

We investigate the dynamical basis of the classic empirical models (specifically, Sersic-Einasto and generalized NFW) that are widely used to describe the distributions of collisionless matter in galaxies. We submit that such a basis is provided by our α-profiles, shown to constitute solutions of the Jeans dynamical equilibrium with physical boundary conditi

Toshiro Hiranouchi, Seiji Hirayama

We study the Chow group of $0$-cycles on the product of elliptic curves over a $p$-adic field. For this abelian variety, it is decided that the structure of the image of the Albanese kernel by the cycle class map.

Olivier Coussy, Jean-Michel Pereira, Jean Vaunat

A thermodynamically consistent extension of the constitutive equations of saturated soils to unsaturated conditions is often worked out through the use a unique 'effective' interstitial pressure, accounting equivalently for the pressures of the saturating fluids acting separately on the internal solid walls of the pore network. The natural candidate

Marie Ferbus-Zanda, Serge Grigorieff

We show that lambda calculus is a computation model which can step by step simulate any sequential deterministic algorithm for any computable function over integers or words or any datatype. More formally, given an algorithm above a family of computable functions (taken as primitive tools, i.e., kind of oracle functions for the algorithm), for every constant

Marie Ferbus-Zanda

We survey diverse approaches to the notion of information: from Shannon entropy to Kolmogorov complexity. Two of the main applications of Kolmogorov complexity are presented: randomness and classification. The survey is divided in two parts published in a same volume. Part II is dedicated to the relation between logic and information system, within the scope

Jean-Philippe Petit, Serge Samper

The aim of this paper is to show through a simple assembly a method of tolerancing analysis (coherent with GPS) developed at LMécA and based on the model of clearance and deviation domains. Tolerancing is an important step in the product design because on it will depend the functionality of the mechanism its assemblibility but also its cost: manufacturing co

Ricardo Gabriel Elias, Alberto Verga

Switching of magnetic vortex cores involves a topological transition characterized by the presence of a magnetization singularity, a point where the magnetization vanishes (Bloch point). We analytically derive the shape of the Bloch point that is an extremum of the free energy with exchange, dipole and the Landau terms for the determination of the local valu

Simon Heybrock

In analogy to Neuberger's double-pass algorithm for the Conjugate Gradient inversion with multi-shifts we introduce a double-pass variant for BiCGstab(ell). One possible application is the overlap operator of QCD at non-zero chemical potential, where the kernel of the sign function is non-Hermitian. The sign function can be replaced by a partial fraction

Ionut Chiose, Matei Toma

The Kähler rank of compact complex surfaces was introduced by Harvey and Lawson in their 1983 paper on Kähler manifolds as a measure of ``kälerianity''. Here we give a partial classification of compact complex surfaces of Kähler rank 1. These are either elliptic surfaces, or Hopf surfaces, or they admit a holomorphic foliation of a very special type.

E. G. Malkovich

We construct in an explicit algebraic form a family of complete noncompact Ricci-flat metrics which generalize Calabi metrics in real dimension $4(n+1)$ and with holonomy $SU(2(n+1))$.

Asaf Shimshovitz, David J. Tannor

We propose a new method for solving quantum mechanical problems, which combines the flexibility of Gaussian basis set methods with the numerical accuracy of the Fourier method. The method is based on the incorporation of periodic boundary conditions into the von Neumann basis of phase space Gaussians [F. Dimler et al., New J. Phys. 11, 105052 (2009)]. In thi

J. M. Brader, M. Siebenbuerger, M. Ballauff, K. Reinheimer

Using a combination of theory, experiment and simulation we investigate the nonlinear response of dense colloidal suspensions to large amplitude oscillatory shear flow. The time-dependent stress response is calculated using a recently developed schematic mode-coupling-type theory describing colloidal suspensions under externally applied flow. For finite stra

M. A. Braun, A. Tarasov

It is shown by numerical calculations that the convoluted forward pomeron propagator in the external field created by a solution of the Balitski-Kovchegov equation in the nuclear matter vanishes at high rapidities. This may open a possibility to apply the perturbative approach for the calculation of pomeron loops.

Hideyuki Saio

Stability of radial and nonradial oscillations of massive supergiants is discussed. The kappa-mechanism and strange-mode instability exciteoscillations having various periods in wide ranges of the upper part of the HR diagram. In addition, in very luminous ($\log L/L_\odot \gtrsim 5.9$) models, monotonously unstable modes exist, which probably indicates the

Akio K. Inoue, K. Kousai, I. Iwata, Y. Matsuda

(Abridged) Deep NB359 imaging with Subaru by Iwata et al. have detected surprisingly strong Lyman continuum (LyC; ~900A in the rest-frame) from some LAEs at z=3.1. However, the redshifts might be misidentified due to a narrow wavelength coverage in previous spectroscopy. We here present new deep spectroscopy covering the observed 4,000-7,000A with VLT/VIMOS

Pablo Castellanos, Simon Casassus, Clive Dickinson, Matias Vidal

An anomalous radio continuum component at cm-wavelengths has been observed in various sources, including dark clouds. This continuum component represents a new property of the ISM. In this work we focus on one particular dark cloud, the bright reflection nebula M 78. The main goal of this work is to invetigate cm-wave continuum emission in a prominent molecu

Ural Bekbaev

In this paper the main results in arXiv:0901.3179v3, related to the matrix representation of polynomial maps, are restated in traditional way of linear algebra assuming that variable vectors are presented as column vectors. Some new results related to that subject are also included. Here one can find the behavior of the matrices of polynomial maps with respe

Pradipta Ghosh

$μν$SSM is an $R$-parity violating non-minimal supersymmetric model which uses right chiral neutrino superfields to solve the $μ$-problem. The $R$-parity violation together with a TeV scale seesaw mechanism using right handed neutrinos are instrumental for the light neutrino mass generation in $μν$SSM. We show that it is possible to accommodate three flavour

Nikolai Dokuchaev

This short note suggests a heuristic method for detecting the dependence of random time series that can be used in the case when this dependence is relatively weak and such that the traditional methods are not effective. The method requires to compare some special functionals on the sample characteristic functions with the same functionals computed for the b

David Jewitt, Harold Weaver, Jessica Agarwal, Max Mutchler

Most main-belt asteroids are primitive rock and metal bodies in orbit about the Sun between Mars and Jupiter. Disruption, through high velocity collisions or rotational spin-up, is believed to be the primary mechanism for the production and destruction of small asteroids and a contributor to dust in the Sun's Zodiacal cloud, while analogous collisions ar

Radu Cazan, Cyrus K. Aidun

Twisted tapes are used to induce swirling flow and improve mixing. The flow induced by a 180 degree twisted tape with length (pitch) 60 mm and diameter 25.4 mm in a circular pipe was investigated using Laser Doppler Velocimetry (LDV) measurements. Tangential velocity profiles downstream of the twisted tape swirler were measured at multiple locations along th

Qingfeng Li, Zhuxia Li

A mean-field potential version of the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model is used to investigate the production of strange baryons, especially the $Λ$s and $\overlineΛ$s, from heavy ion collisions at SPS energies. It is found that, with the consideration of both formed and pre-formed hadron potentials in UrQMD, the transverse mass and

Rajneesh Bhardwaj, Jon P. Longtin, Daniel Attinger

The objective of this work is to investigate the coupling of fluid dynamics, heat transfer and mass transfer during the impact and evaporation of droplets on a heated solid substrate. A laser-based thermoreflectance method is used to measure the temperature at the solid-liquid interface, with a time and space resolution of 100 μs and 20 μm, respectively. Iso

Kazunori Tanaka, Takumi Araki, Katsurou Hanzawa

In heavy-fermion compounds, the crossover from the localized to itinerant heavy-fermion state is observed with lowering temperature, frequently accompanied by magnetism. Ordering vectors of magnetism often vary with applying pressure or with substituting atoms. In Ce(Pd$_{1-x}$M$_x$)$_2$Al$_3$ with $\mathrm{M}=\mathrm{Ag,Cu}$, the $(0,0,1/2)$-antiferromagnet

Rajneesh Bhardwaj, Xiaohua Fang, Ponisseril Somasundaran, Daniel Attinger

The shape of deposits obtained from drying drops containing colloidal particles matters for technologies such as inkjet printing, microelectronics and bioassay manufacturing. In this work, the formation of deposits during the drying of nanoliter drops containing colloidal particles is investigated experimentally with microscopy and profilometry, and theoreti

E. Ben-Naim

We study how the order of N independent random walks in one dimension evolves with time. Our focus is statistical properties of the inversion number m, defined as the number of pairs that are out of sort with respect to the initial configuration. In the steady-state, the distribution of the inversion number is Gaussian with the average <m>~N^2/4 and the stan

Bian Qian, Kenneth S. Breuer

The complex behavior of drop deposition on a hydrophobic surface is considered by looking at a model problem in which the evolution of a constant-volume liquid bridge is studied as the bridge is stretched. The bridge is pinned with a fixed diameter at the upper contact point, but the contact line at the lower attachment point is free to move on a smooth subs

Rajneesh Bhardwaj, Xiaohua Fang, Daniel Attinger

An efficient way to precisely pattern particles on solid surfaces is to dispense and evaporate colloidal drops, as for bioassays. The dried deposits often exhibit complex structures exemplified by the coffee ring pattern, where most particles have accumulated at the periphery of the deposit. In this work, the formation of deposits during the drying of nanoli

Rajneesh Bhardwaj, Jon P. Longtin, Daniel Attinger

This work investigates the impingement of a liquid microdroplet onto a glass substrate at different temperatures. A finite-element model is applied to simulate the transient fluid dynamics and heat transfer during the process. Results for impingement under both isothermal and non-isothermal conditions are presented for four liquids: isopropanol, water, diele

Rajneesh Bhardwaj, Daniel Attinger

The objective of this work is to develop and validate a numerical model to study wetting during the impact of millimeter-size drops on a flat, smooth, solid substrate under isothermal or non-isothermal conditions. A finite-element modeling is used to simulate the transient fluid dynamics and heat transfer, considering Laplace forces on the liquid-gas boundar

Ilya Toytman, Alexander Silbergleit, Dmitri Simanovski, Daniel Palanker

Transparent biological tissues can be precisely dissected with ultrafast lasers using optical breakdown in the tight focal zone. Typically, tissues are cut by sequential application of pulses, each of which produces a single cavitation bubble. We investigate the hydrodynamic interactions between simultaneous cavitation bubbles originating from multiple laser

Qi-Lin Yang

We prove that if $B$ is a $k$-positive holomorphic line bundle on a compact hyperkähler manifold $M,$ then $H^p (M,Ω^q\otimes B)=0$ for $p>n+[\frac{k}{2}]$ and any nonnegative integer $q.$ In a special case $k=0$ and $q=0$ we recover a vanishing theorem of Verbitsky&#39;s with a little stronger assumption.

M. Sharif, H. Rizwana Kausar

In this paper, we solve the field equations in metric f(R) gravity for Bianchi type VI_0 spacetime and discuss evolution of the expanding universe. We find two types of non-vacuum solutions by taking isotropic and anisotropic fluids as the source of matter and dark energy. The physical behavior of these solutions is analyzed and compared in the future evolut

Umberto Rivieccio

The aim of this work is to develop a study from the perspective of Abstract Algebraic Logic of some bilattice-based logical systems introduced in the nineties by Ofer Arieli and Arnon Avron. The motivation for such an investigation has two main roots. On the one hand there is an interest in bilattices as an elegant formalism that gave rise in the last two de

Salim El Rouayheb, Kannan Ramchandran

We introduce a new class of exact Minimum-Bandwidth Regenerating (MBR) codes for distributed storage systems, characterized by a low-complexity uncoded repair process that can tolerate multiple node failures. These codes consist of the concatenation of two components: an outer MDS code followed by an inner repetition code. We refer to the inner code as a Fra

Primoz Potocnik, Pablo Spiga, Gabriel Verret

It has long been known that there exist finite connected tetravalent arc-transitive graphs with arbitrarily large vertex-stabilisers. However, beside a well known family of exceptional graphs, related to the lexicographic product of a cycle with an edgeless graph on two vertices, only a few such infinite families of graphs are known. In this paper, we presen

Joris Vankerschaver, Hiroaki Yoshimura, Melvin Leok, Jerrold E. Marsden

We consider the concept of Stokes-Dirac structures in boundary control theory proposed by van der Schaft and Maschke. We introduce Poisson reduction in this context and show how Stokes-Dirac structures can be derived through symmetry reduction from a canonical Dirac structure on the unreduced phase space. In this way, we recover not only the standard structu

Primoz Potocnik, Pablo Spiga, Gabriel Verret

The main result of this paper is that, if $Γ$ is a connected 4-valent $G$-arc-transitive graph and $v$ is a vertex of $Γ$, then either $Γ$ is one of a well understood infinite family of graphs, or $|G_v|\leq 2^43^6$ or $2|G_v|\log_2(|G_v|/2)\leq |\VΓ|$ and that this last bound is tight. As a corollary, we get a similar result for $3$-valent vertex-transitive

Panayotis Spathis, Subhajit Biswas, Stefano Roddaro, Lucia Sorba

We report the fabrication and characterization of superconducting quantum interference devices (SQUIDs) based on InAs nanowires and vanadium superconducting electrodes. These mesoscopic devices are found to be extremely robust against thermal cycling and to operate up to temperatures of $\sim2.5$~K with reduced power dissipation. We show that our geometry al

Xingjie Helen Li, Mitchell Luskin

The accurate and efficient computation of the deformation of crystalline solids requires the coupling of atomistic models near lattice defects such as cracks and dislocations with coarse-grained models away from the defects. Quasicontinuum methods utilize a strain energy density derived from the Cauchy-Born rule for the coarse-grained model. Several quasicon

Donald Goldfarb, Shiqian Ma, Katya Scheinberg

We present in this paper first-order alternating linearization algorithms based on an alternating direction augmented Lagrangian approach for minimizing the sum of two convex functions. Our basic methods require at most $O(1/ε)$ iterations to obtain an $ε$-optimal solution, while our accelerated (i.e., fast) versions of them require at most $O(1/\sqrtε)$ ite

Mehrdad Mirbabayi

The possibility of the formation of a condensate of charged spin-0 nuclei inside white dwarf cores, studied in arXiv:0806.3692 and arXiv:0904.4267, is pursued further. It has been shown, for cores composed mainly of one element (Helium or Carbon), that after condensation phonons become massive and the specific heat drops by about two orders of magnitude. In

Bill Mance

In \cite{SchmidtGames}, W. Schmidt proved that the set of non-normal numbers in base $b$ is a {\it winning set}. We generalize this result by proving that many sets of non-normal numbers with respect to the Cantor series expansion are winning sets. As an immediate consequence, these sets will be shown to have full Hausdorff dimension.

Neal Dalal, Yoram Lithwick, Michael Kuhlen

A longstanding puzzle of fundamental importance in modern cosmology has been the origin of the nearly universal density profiles of dark matter halos found in N-body simulations -- the so-called NFW profile. We show how this behavior may be understood, simply, by applying adiabatic contraction to peaks of Gaussian random fields. We argue that dynamical frict

Jacek Wendykier, Adam Lipowski, Antonio Luis Ferreira

In the present paper we study a lattice model of two species competing for the same resources. Monte Carlo simulations for d=1, 2, and 3 show that when resources are easily available both species coexist. However, when the supply of resources is on an intermediate level, the species with slower metabolism becomes extinct. On the other hand, when resources ar

Bill Mance

Fix a sequence of integers $Q=\{q_n\}_{n=1}^\infty$ such that $q_n$ is greater than or equal to 2 for all $n$. In this paper, we improve upon results by J. Galambos and F. Schweiger showing that almost every (in the sense of Lebesgue measure) real number in $[0,1)$ is $Q$-normal with respect to the $Q$-Cantor series expansion for sequences $Q$ that satisfy a

Tomas Andrade, Donald Marolf, Cedric Deffayet

It has been argued that holography in gravitational theories is related to the existence of a particularly useful Gauss Law that allows energy to be measured at the boundary. The present work investigates the extent to which such Gauss Laws follow from diffeomorphism invariance. We study parametrized field theories, which are a class of diffeomorphism-invari

G. Cresci, F. Mannucci, R. Maiolino, A. Marconi

It has recently been suggested that galaxies in the early Universe can grow through the accretion of cold gas, and that this may have been the main driver of star formation and stellar mass growth. Because the cold gas is essentially primordial, it has a very low abundance of elements heavier than helium (metallicity). As it is funneled to the centre of a ga

Yarema A. Prykarpatsky, Nikolai N. Bogolubov, Anatoliy K. Prykarpatsky, Valeriy H. Samoylenko

A gradient-holonomic approach for the Lax type integrability analysis of differentialdiscrete dynamical systems is devised. The asymptotical solutions to the related Lax equation are studied, the related gradient identity is stated. The integrability of a discrete nonlinear Schredinger type dynamical system is treated in detail.

V. R. Supradeepa, Andrew M. Weiner

We introduce a new cascaded four-wave mixing technique which scales up the bandwidth of frequency combs generated by phase modulation of a continuous wave laser while simultaneously enhancing the spectral flatness. As a result we demonstrate a 10 GHz frequency comb with over 100 lines in a 10-dB bandwidth in which a record 75 lines are within a flatness of 1

Steven Rayan

Co-Higgs bundles are Higgs bundles in the sense of Simpson, but with Higgs fields that take values in the tangent bundle instead of the cotangent bundle. Given a vector bundle on P^1, we find necessary and sufficient conditions on its Grothendieck splitting for it to admit a stable Higgs field. We characterize the rank-2, odd-degree moduli space as a univers

Creighton K. Thomas, Helmut G. Katzgraber

Computing the ground state of Ising spin-glass models with p-spin interactions is, in general, an NP-hard problem. In this work we show that unlike in the case of the standard Ising spin glass with two-spin interactions, computing ground states with p=3 is an NP-hard problem even in two space dimensions. Furthermore, we present generic exact and heuristic al

S. Spatzek, A. Greilich, Sophia E. Economou, A. Schwan

Coherent interactions between spins in quantum dots are a key requirement for quantum gates. We have performed pump-probe experiments in which pulsed lasers emitting at different photon energies manipulate two distinct subsets of electron spins within an inhomogeneous InGaAs quantum dot ensemble. The spin dynamics are monitored through their precession about

Peter Hinow, Vahid Rezania, Manu Lopus, Mary Ann Jordan

We propose a stochastic model that accounts for the growth, catastrophe and rescue processes of steady state microtubules assembled from MAP-free tubulin. Both experimentally and theoretically we study the perturbation of microtubule dynamic instability by S-methyl-D-DM1, a synthetic derivative of the microtubule-targeted agent maytansine and a potential ant

Anders W. Sandvik, Valeri N. Kotov, Oleg P. Sushkov

We consider the quantum phase transition between a Neel antiferromagnet and a valence-bond solid (VBS) in a two-dimensional system of S=1/2 spins. Assuming that the excitations of the critical ground state are linearly dispersing deconfined spinons obeying Bose statistics, we derive expressions for the specific heat and the magnetic susceptibility at low tem

Graeme Kemkes, Cristiane M. Sato, Nicholas Wormald

We determine an asymptotic formula for the number of labelled 2-connected (simple) graphs on $n$ vertices and $m$ edges, provided that $m-n\to\infty$ and $m=O(n\log n)$ as $n\to\infty$. This is the entire range of $m$ not covered by previous results. The proof involves determining properties of the core and kernel of random graphs with minimum degree at leas

Serguei A. Mokhov

We present a machine learning approach to static code analysis and fingerprinting for weaknesses related to security, software engineering, and others using the open-source MARF framework and the MARFCAT application based on it for the NIST&#39;s SATE2010 static analysis tool exposition workshop found at http://samate.nist.gov/SATE2010Workshop.html

V. Dobrovolskas, A. Kučinskas, H. -G. Ludwig, E. Caffau

In this work we have used 3D hydrodynamical (CO5BOLD) and 1D hydrostatic (LHD) stellar atmosphere models to study the importance of convection and horizontal temperature inhomogeneities in stellar abundance work related to late-type giants. We have found that for a number of key elements, such as Na, Mg, Si, Ca, Ti, Fe, Ni, Zn, Ba, Eu, differences in abundan

Hui Li, Martin Olbermann, Donald Stanley

Let the circle act effectively in a Hamiltonian fashion on a compact symplectic manifold $(M, ω)$. Assume that the fixed point set $M^{S^1}$ has exactly two components, $X$ and $Y$, and that $\dim(X) + \dim(Y) +2 = \dim(M)$. We first show that $X$, $Y$ and $M$ are simply connected. Then we show that, up to $S^1$-equivariant diffeomorphism, there are finitely

Erwin Suazo, Sergei K. Suslov

We construct one soliton solutions for the nonlinear Schroedinger equation with variable quadratic Hamiltonians in a unified form by taking advantage of a complete (super) integrability of generalized harmonic oscillators. The soliton wave evolution in external fields with variable quadratic potentials is totally determined by the linear problem, like motion

Adi Zolotov, David W. Hogg, Beth Willman

We develop a technique to investigate the possibility that some of the recently discovered ultra-faint dwarf satellites of the Milky Way might be cusp caustics rather than gravitationally self-bound systems. Such cusps can form when a stream of stars folds, creating a region where the projected 2-D surface density is enhanced. In this work, we construct a Po

James Colliander, Soonsik Kwon, Tadahiro Oh

We study growth of higher Sobolev norms of solutions to the one-dimensional periodic nonlinear Schrodinger equation (NLS). By a combination of the normal form reduction and the upside-down I-method, we establish \|u(t)\|_{H^s} \lesssim (1+|t|)^{α(s-1)+} with α= 1 for a general power nonlinearity. In the quintic case, we obtain the above estimate with α= 1/2

Vivienne Wild, Paul C. Hewett

The Sloan Digital Sky Survey (SDSS) automated spectroscopic reduction pipeline provides >1.5 million intermediate resolution, R~2000, moderate signal-to-noise ratio (SNR), SNR~15, astronomical spectra of unprecedented homogeneity that cover the wavelength range 3800-9200AA. However, there remain significant systematic residuals in many spectra due to the sub

Linda C. Watson, Eva Schinnerer, Paul Martini, Torsten Boeker

We study the neutral hydrogen properties of a sample of 20 bulgeless disk galaxies (Sd - Sdm Hubble types), an interesting class that can be used to constrain galaxy formation and evolution, especially the role of mergers versus internal processes. Our sample is composed of nearby (within 32 Mpc), moderately inclined galaxies that bracket the circular veloci

C. -C. Chen, R. Applegate, B. Moritz, T. P. Devereaux

Imaging the magnetic fields around a non-magnetic impurity can provide a clear benchmark for quantifying the degree of magnetic frustration. Focusing on the strongly frustrated $J_1$-$J_2$ model and the spatially anisotropic $J_{1a}$-$J_{1b}$-$J_2$ model, very distinct low energy behaviors reflect different levels of magnetic frustration. In the $J_1$-$J_2$

Tamara Bogdanovic, Tanja Bode, Roland Haas, Pablo Laguna

What are the properties of accretion flows in the vicinity of coalescing supermassive black holes (SBHs)? The answer to this question has direct implications for the feasibility of coincident detections of electromagnetic (EM) and gravitational wave (GW) signals from coalescences. Such detections are considered to be the next observational grand challenge th

Paul M. Hohler

The heavy-quark QCD sum rules are applied to a model of charmonium based upon the gauge/gravity duality. We find that there is strong agreement between the moments of the polarization function calculated from the holographic model and the experimental data suggesting that the model is consistent with the heavy-quark QCD sum rules at zero temperature.

David R. Rodriguez, M. S. Bessell, B. Zuckerman, Joel H. Kastner

We describe a new method to identify young, late-type stars within ~150 pc of the Earth that employs visual or near-infrared data and the GALEX GR4/5 database. For spectral types later than K5, we demonstrate that the ratio of GALEX near-ultraviolet (NUV) to visual and near-IR emission is larger for stars with ages between 10 and 100 Myr than for older, main

V. V. Gvaramadze, J. Pflamm-Altenburg, P. Kroupa

Using archival Spitzer Space Telescope data, we identified for the first time a dozen runaway OB stars in the Small Magellanic Cloud (SMC) through the detection of their bow shocks. The geometry of detected bow shocks allows us to infer the direction of motion of the associated stars and to determine their possible parent clusters and associations. One of th

Hao Pan, Zhi-Wei Sun

In this paper we prove three conjectures on congruences involving central binomial coefficients or Lucas sequences. Let $p$ be an odd prime and let $a$ be a positive integer. We show that if $p\equiv 1\pmod{4}$ or $a>1$ then $$ \sum_{k=0}^{\lfloor\frac34p^a\rfloor}\binom{-1/2}k\equiv\left(\frac{2}{p^a}\right)\pmod{p^2}, $$ where $(-)$ denotes the Jacobi symb