April 2007 arXiv papers — page 11

Bei Jia

We discuss in this paper two ways of defining the concept of "effective field theory": effective field theory defined by low energy effectiveness and effective field theory defined by 4D effectiveness out of higher dimensions. We argue that these two views are actually equivalent, that effective field theories at low energy can in fact be regarded as

Zhen-Qiang Yin, Zheng-Fu Han, Wei Chen, Fang-Xing Xu

Decoy State Quantum Key Distribution (QKD), being capable of beating PNS attack and uncon- ditionally secure, have become an attractive one recently. But, in many QKD systems, disturbances of transmission channel make quantum bit error rate (QBER) increase which limits both security distance and key bit rate of real-life decoy state QKD systems. We demonstra

Thomas Fiedler

We construct a 2-variable link polynomial, called $W_L$, for classical links by considering simultaneously the Kauffman state models for the Alexander and for the Jones polynomials. We conjecture that this polynomial is the product of two 1-variable polynomials, one of which is the Alexander polynomial. We refine $W_L$ to an ordered set of 3-variable polynom

Kazuhiro Yamamoto, David Parkinson, Takashi Hamana, Robert C. Nichol

We consider the extent to which future imaging surveys of galaxies can distinguish between dark energy and modified gravity models for the origin of the cosmic acceleration. Dynamical dark energy models may have similar expansion rates as models of modified gravity, yet predict different growth of structure histories. We parameterize the cosmic expansion by

Andrei Teleman

We describe the positive cone and the pseudo-effective cone of a non-Kählerian surface. We use these results for two types of applications: - Describe the set $σ(X)$ of possible total Ricci scalars associated with Gauduchon metrics of fixed volume 1 on a fixed non-Kähhlerian surface, and decide whether the assignment $X\mapstoσ(X)$ is a deformation invariant

E. Yu. Lerner

Let $x$ be a cyclic sequence of $n$ elements of the finite field $\mathbb{F}_q$ (the first element immediately follows the $n$-th one). Let us define the operation $Δ$ as the transition from $x$ to the sequence of differences of the neighbouring elements from $x$. The aim of this work is to give graphs of the dynamic system $Δ$ for $q=2$, $n\le 300$ and $q=3

Ki-Young Choi, Jinn-Ouk Gong

We study the evolution of the universe which contains a multiple number of non-relativistic scalar fields decaying into both radiation and pressureless matter. We present a powerful analytic formalism to calculate the matter and radiation curvature perturbations, and find that our analytic estimates agree with full numerical results within an error of less t

V. L. Kulinskii

Using the canonical transformation of the order parameter which restores the Ising symmetry of the Hamiltonian we derive the expression for the Tolman length as a sum of two terms. One of them is the term generated by the fluctuations of the order parameter the other one is due to the entropy. The leading singular behavior of the Tolman length near the criti

Giacomo Dossena

In a 1967 paper, Zeeman proposed a new topology for Minkowski spacetime, physically motivated but much more complicated than the standard one. Here a detailed study is given of some properties of the Zeeman topology which had not been considered at the time. The general setting refers to Minkowski spacetime of any dimension k+1. In the special case k=1, a fu

Frederic Brechenmacher

What did "algebra" mean before the development of the algebraic theories of the 20th century ? This paper stresses the identities taken by the algebraic practices developped during the century long discussion around the equation around the equation of secular inequalities (1766- 1874). In 1874, a strong controversy on the theory of bilinear and quadr

Frederic Brechenmacher

During the whole of 1874, Camille Jordan and Leopold Kronecker quar- relled vigorously over the organisation of the theory of bilinear forms. That theory promised a "general" and "homogeneous" treatment of numerous questions arising in various 19th-century theoretical contexts, and it hinged on two theorems, stated independently by Jordan and

Shinobu Hosono, Yukiko Konishi

We solve Bershadsky-Cecotti-Ooguri-Vafa (BCOV) holomorphic anomaly equation to determine the higher genus Gromov-Witten invariants ($g \leq 5$) of the derived equivalent Calabi-Yau threefolds, which are of the appropriate codimensions in the Grassmannian Gr(2,7) and the Pfaffian Pf(7).

Julia Kempe, Hirotada Kobayashi, Keiji Matsumoto, Ben Toner

We establish the first hardness results for the problem of computing the value of one-round games played by a verifier and a team of provers who can share quantum entanglement. In particular, we show that it is NP-hard to approximate within an inverse polynomial the value of a one-round game with (i) quantum verifier and two entangled provers or (ii) classic

David Eppstein, Jean-Claude Falmagne, Hasan Uzun

Current techniques for generating a knowledge space, such as QUERY, guarantees that the resulting structure is closed under union, but not that it satisfies wellgradedness, which is one of the defining conditions for a learning space. We give necessary and sufficient conditions on the base of a union-closed set family that ensures that the family is well-gra

Allan Sly

Counter to the general notion that the regular tree is the worst case for decay of correlation between sets and nodes, we produce an example of a multi-spin interacting system which has uniqueness on the $d$-regular tree but does not have uniqueness on some infinite $d$-regular graphs.

Monika Sharma, Sunil Dogra, Neeraj Gupta

The energy and system size dependence of pseudorapidity ($η$) and multiplicity distributions of photons are measured in the region -2.3 $\leq$ $η$ $\leq$ -3.7 for Cu + Cu collisions at $\sqrt{s_{NN}}$ = 200 and 62.4 GeV. Photon multiplicity measurements at forward rapidity have been carried out using a Photon Multiplicity Detector (PMD) in the STAR experimen

H-S. Kim, S. Kim, J. Y. Bak, M. Garcia

We compare the CO 2-1 observations against previously taken CO 4-3 observations and analyze the spatial distribution of young stellar objects (YSO's) within the cloud using the Spitzer IRAC observations of the 30 Doradus complex. Both peaks of CO 2-1 and 4-3 emitting clouds coincide with the densest region of the filaments where multiple shells are colli

Toshifumi Jittoh, Kazunori Kohri, Masafumi Koike, Joe Sato

Modification of standard big-bang nucleosynthesis is considered in the minimal supersymmetric standard model to resolve the excessive theoretical prediction of the abundance of primordial lithium 7. We focus on the stau as a next-lightest superparticle, which is long lived due to its small mass difference with the lightest superparticle. It provides a number

Antal A. Járai, Russell Lyons

We study Abelian sandpiles on graphs of the form $G \times I$, where $G$ is an arbitrary finite connected graph, and $I \subset \Z$ is a finite interval. We show that for any fixed $G$ with at least two vertices, the stationary measures $μ_I = μ_{G \times I}$ have two extremal weak limit points as $I \uparrow \Z$. The extremal limits are the only ergodic mea

S. Kim, C. Park

We have analyzed the HI aperture synthesis image of the Large Magellanic Cloud (LMC), using an objective and quantitative measure of topology to understand the HI distribution hosting a number of holes and clumps of various sizes in the medium. The HI distribution shows different topology at four different chosen scales. At the smallest scales explored (19-2

I. Kuljanishvili, C. Kayis, J. F. Harrison, C. Piermarocchi

Semiconductor devices continue to press into the nanoscale regime, and new applications have emerged for which the quantum properties of dopant atoms act as the functional part of the device, underscoring the necessity to probe the quantum structure of small numbers of dopant atoms in semiconductors[1-3]. Although dopant properties are well-understood with r

Chenjie Wang, Guang-Can Guo, Lixin He

The ground state structural, electronic and magnetic properties of multiferroic TbMn$_2$O$_5$ are investigated via first-principles calculations. We show that the ferroelectricity in TbMn$_2$O$_5$ is driven by the non-centrosymmetric magnetic ordering, without invoking the spin-orbit coupling and non-collinear spins. The {\it intrinsic} electric polarization

David P. Blecher, Kay Kirkpatrick, Matthew Neal, Wend Werner

This is a companion to recent papers of the authors; here we construct the `noncommutative Shilov boundary' of a (possibly nonunital) selfadjoint ordered space of Hilbert space operators. The morphisms in the universal property of the boundary preserve order. As an application, we consider `maximal' and `minimal' unitizations of such ordered oper

Olympia Hadjiliadis, H. Vincent Poor

This work examines the problem of sequential detection of a change in the drift of a Brownian motion in the case of two-sided alternatives. Applications to real life situations in which two-sided changes can occur are discussed. Traditionally, 2-CUSUM stopping rules have been used for this problem due to their asymptotically optimal character as the mean tim

N. E. Kassim, T. J. W. Lazio, W. C. Erickson, R. A. Perley

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and resolution (~25 arcsec) for low-frequency observations. We review the hardware, the calibration and imaging strategies, compar

Ilia A. Solov'yov, Alexander V. Yakubovich, Andrey V. Solov'yov, Walter Greiner

In the present paper we present results of calculations obtained with the use of the theoretical method described in our preceding paper [1] and perform detail analysis of alpha helix-random coil transition in alanine polypeptides of different length. We have calculated the potential energy surfaces of polypeptides with respect to their twisting degrees of f

Alberto Buzzoni

The connection between AGB evolution of stellar populations and infrared vs. ultraviolet properties of the parent galaxies is reviewed relying on the updated lookout provided by population-synthesis theory. In particular, planetary-nebula events and hot horizontal-branch evolution are assessed in a unitary view to outline a plain general picture of galaxy sp

Andrei Gruzinov

A spherically symmetrical ultra-relativistic blast wave is not an attractor of a generic asymmetric explosion. Spherical symmetry is reached only by the time the blast wave slows down to non-relativistic velocities, when the Sedov-Taylor-von Neumann attractor solution sets in. We show however, that a directed relativistic explosion, with the explosion moment

Alexander V. Yakubovich, Ilia A. Solov'yov, Andrey V. Solov'yov, Walter Greiner

In this paper we suggest a theoretical method based on the statistical mechanics for treating the alpha-helix-random coil transition in alanine polypeptides. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes essential thermodyn

Eric F. Bell, Xian Zhong Zheng, Casey Papovich, Andrea Borch

Recent observations have demonstrated a significant growth in the integrated stellar mass of the red sequence since z=1, dominated by a steadily increasing number of galaxies with stellar masses M* < 10^11 M_sun. In this paper, we use the COMBO-17 photometric redshift survey in conjunction with deep Spitzer 24 micron data to explore the relationship between

M. Kunz, N. Aghanim, A. Riazuelo, O. Forni

We explore the main physical processes which potentially affect the topological signal in the Cosmic Microwave Background (CMB) for a range of toroidal universes. We consider specifically reionisation, the integrated Sachs-Wolfe (ISW) effect, the size of the causal horizon, topological defects and primordial gravitational waves. We use three estimators: the

Karoline Wiesner, James P. Crutchfield

We analyze how measured quantum dynamical systems store and process information, introducing sofic quantum dynamical systems. Using recently introduced information-theoretic measures for quantum processes, we quantify their information storage and processing in terms of entropy rate and excess entropy, giving closed-form expressions where possible. To illust

Florin Moldoveanu

General relativity allows solutions exhibiting closed timelike curves. Time travel generates paradoxes and quantum mechanics generalizations were proposed to solve those paradoxes. The implications of self-consistent interactions on acausal region of space-time are investigated. If the correspondence principle is true, then all generalizations of quantum mec

R. Kothes, S. M. Dougherty

The goal of this study is to determine a distance to Westerlund 1 independent of the characteristics of the stellar population and to study its neutral environment, using observations of atomic hydrogen. The HI observations are taken from the Southern Galactic Plane Survey to study HI absorption in the direction of the HII region created by the members of We

Rob P. Olling

We propose a MIDEX-class space mission with the goal to find and characterize roughly 10,000 transiting planets. When transits occur, a much more detailed characterization of the planet is possible and so a large data base of transiting planets will provide planets with a large range in periods and radii for follow-up studies. Our survey will be all-sky and

K. I. Mazzitello, C. M. Arizmendi, H. G. E. Hentschel

In most vertebrate species, the body axis is generated by the formation of repeated transient structures called somites. This spatial periodicity in somitogenesis has been related to the temporally sustained oscillations in certain mRNAs and their associated gene products in the cells forming the presomatic mesoderm. The mechanism underlying these oscillatio

S. Goldstein, W. Struyve

In Bohmian mechanics the distribution $|ψ|^2$ is regarded as the equilibrium distribution. We consider its uniqueness, finding that it is the unique equivariant distribution that is also a local functional of the wave function $ψ$.

Brant C. Jones

We provide a non-recursive description for the bounded admissible sets of masks used by Deodhar&#39;s algorithm to calculate the Kazhdan--Lusztig polynomials $P_{x,w}(q)$ of type $A$, in the case when $w$ is hexagon avoiding and maximally clustered. This yields a combinatorial description of the Kazhdan--Lusztig basis elements of the Hecke algebra associated

Mark. A. Lindeman, Kathleen A. Barger, Donald E. Brandl, S. Gwynne Crowder

Impedance measurements provide a useful probe of the physics of bolometers and calorimeters. We describe a method for measuring the complex impedance of these devices. In previous work, stray impedances and readout electronics of the measurement apparatus have resulted in artifacts in the impedance data. The new technique allows experimenters to find an inde

E. Jimenez-Bailon, N. Loiseau, M. Guainazzi, G. Matt

We report on XMM-Newton observations of three nearby galaxy pairs, AM0707-273, AM1211-465, and AM2040-674. All six galaxies were previously classified as HII galaxies based on optical and IR spectroscopic analysis. All galaxies were detected with XMM-Newton and each member was isolated and analyzed independently. The X-ray spectra reveal strong evidence of A

S. B. Athar, CLEO Collaboration

We report on a search for the radiative decay of Upsilon(1S) to the pseudoscalar mesons eta and etaprime in 21.2 +/- 0.2 times 10^6 Upsilon(1S) decays collected with the CLEO III detector at the Cornell Electron Storage Ring (CESR). The eta meson was reconstructed in the three modes eta to gamma-gamma, eta to pi+pi-pi0 and eta to 3pi0. The etaprime meson was

D. Klochkov, R. Staubert, S. Tsygankov, A. Lutovinov

First results of observations of the low mass X-ray binary Her X-1/HZ Her performed by the INTEGRAL satellite in July-August 2005 are presented. A significant part of one 35 day main-on state was covered. The cyclotron line in the X-ray spectrum is well observed and its position and shape, as well as its variability with time and phase of the 1.24 s pulsatio

Evgeny Smirnov

The classical Ehresmann-Bruhat order describes the possible degenerations of a pair of flags in a finite-dimensional vector space V; or, equivalently, the closure of an orbit of the group GL(V) acting on the direct product of two full flag varieties. We obtain a similar result for triples consisting of two subspaces and a partial flag in V; this is equivalen

Klaus Hornberger

A general method is discussed to obtain Markovian master equations which describe the interaction with the environment in a microscopic and non-perturbative fashion. It is based on combining time-dependent scattering theory with the concept of continuous quantum measurements. The applications to the case of a Brownian point particle and to the case of a comp

Rob P. Olling

The astrometric signature imposed by a planet on its primary increases substantially towards longer periods (proportinal to P^2/3), so that long-period planets can be more easily detected, in principle. For example, a one Solar-mass (M_Sun) star would be pulled by roughly 1 mas by a one Jupiter-mass (M_J) planet with a period of one-hundred years at a distan

Milan Janjić

Sequences whose terms are equal to the number of functions with specified properties are considered. Properties are based on the notion of derangements in a more general sense. Several sequences which generalize the standard notion of derangements are thus obtained. These sequences generate a number of integer sequences from the well-known Sloane&#39;s encyc

Benjamin R. Safdi, Harvey Segur

It is known that an explosive instability can occur when nonlinear waves propagate in certain media that admit 3-wave mixing. The purpose of this paper is to show that explosive instabilities can occur even in media that admit no 3-wave mixing. Instead, the instability is caused by 4-wave mixing: four resonantly interacting wavetrains gain energy from a back

Michael J. Hartmann, Fernando G. S. L. Brandao, Martin B. Plenio

We show that atoms trapped in micro-cavities that interact via exchange of virtual photons can model an anisotropic Heisenberg spin-1/2 chain in an external magnetic field. All parameters of the effective Hamiltonian can individually be tuned via external lasers. Since the occupation of excited atomic levels and photonic states are strongly suppressed, the e

Maurice Kleman, Jacques Friedel

Disclinations, first observed in mesomorphic phases, are relevant to a number of ill-ordered condensed matter media, with continuous symmetries or frustrated order. They also appear in polycrystals at the edges of grain boundaries. They are of limited interest in solid single crystals, where, owing to their large elastic stresses, they mostly appear in close

Peter A. Parker, Patrick Mitran, Daniel W. Bliss, Vahid Tarokh

Cooperative diversity systems are wireless communication systems designed to exploit cooperation among users to mitigate the effects of multipath fading. In fairly general conditions, it has been shown that these systems can achieve the diversity order of an equivalent MISO channel and, if the node geometry permits, virtually the same outage probability can

R. M. Sambruna, J. N. Reeves, V. Braito

We present the results of the analysis of an archival 15 ks XMM-Newton observation of the nearby (z=0.057) radio-loud source 3C445, optically classified as a Broad-Line Radio Galaxy. While the RGS data are of insufficient quality to allow a meaningful analysis, the EPIC data show a remarkable X-ray spectrum. The 2-10 keV continuum is described by a heavily a

Jalil Ouazzani, Yves Garrabos

A new algorithm has been developed to compute low Mach Numbers supercritical fluid flows. The algorithm is applied using a finite volume method based on the SIMPLER algorithm. Its main advantages are to decrease significantly the CPU time, and the possibility for supercritical fluid flow modelisation to use other discretisation methods (such as spectral meth

M. B. N. Kouwenhoven, M. Bureau, S. Kim, P. T. de Zeeuw

As part of an effort to enlarge the number of well-studied Magellanic-type galaxies, we obtained broadband optical imaging and neutral hydrogen radio synthesis observations of the dwarf irregular galaxy ESO 364-G 029. The optical morphology characteristically shows a bar-like main body with a one-sided spiral arm, an approximately exponential light distribut

Ryan N. Gutenkunst, Fergal P. Casey, Joshua J. Waterfall, Christopher R. Myers

Successful predictions are among the most compelling validations of any model. Extracting falsifiable predictions from nonlinear multiparameter models is complicated by the fact that such models are commonly sloppy, possessing sensitivities to different parameter combinations that range over many decades. Here we discuss how sloppiness affects the sorts of d

A. Enciso, F. Finkel, A. Gonzalez-Lopez, M. A. Rodriguez

In this paper we study a novel spin chain with nearest-neighbors interactions depending on the sites coordinates, which in some sense is intermediate between the Heisenberg chain and the spin chains of Haldane-Shastry type. We show that when the number of spins is sufficiently large both the density of sites and the strength of the interaction between consec

F. C. Carvalho, J. S. Alcaniz, J. A. S. Lima, R. Silva

A new inflationary scenario whose exponential potential $V(Φ)$ has a quadratic dependence on the field $Φ$ in addition to the standard linear term is confronted with the tree-year observations of the Wilkinson-Microwave Anisotropy Probe and the Sloan Digital Sky Survey data. The number of e-folds ($N$), the ratio of tensor-to-scalar perturbations ($r$), the

E. A. Popova, D. V. Volkov, A. N. Vasiliev, A. A. Demidov

We have studied the thermodynamic properties of single-crystalline TbFe3(BO3)4. Magnetization measurements have been carried out as a function of magnetic field (up to 50 T) and temperature up to 350K with the magnetic field both parallel and perpendicular to the trigonal c-axis of the crystal. The specific heat has been measured in the temperature range 2-3

Alain Corfdir

We consider the stability of a porous medium submitted to a steady-state flow with free-boundary. Assuming some hypotheses, it is possible to implement the kinematic method by using an approximate pressure field bounding the true pressure field from below. We are interested in finding such approximate pressure fields and in proving that they bound the true p

C. Wigger, W. Hajdas, A. Zehnder, K. Hurley

The Ge spectrometer of the RHESSI satellite is sensitive to Gamma Ray Bursts (GRBs) from about 40 keV up to 17 MeV, thus ideally complementing the Swift/BAT instrument whose sensitivity decreases above 150 keV. We present preliminary results of spectral fits of RHESSI GRB data. After describing our method, the RHESSI results are discussed and compared with S

Stefano Berti, Cristobal Lopez, Davide Vergni, Angelo Vulpiani

An autocatalytic reacting system with particles interacting at a finite distance is studied. We investigate the effects of the discrete-particle character of the model on properties like reaction rate, quenching phenomenon and front propagation, focusing on differences with respect to the continuous case. We introduce a renormalized reaction rate depending b

Ender Tekin, Aylin Yener

We consider two-way wire-tap channels, where two users are communicating with each other in the presence of an eavesdropper, who has access to the communications through a multiple-access channel. We find achievable rates for two different scenarios, the Gaussian two-way wire-tap channel, (GTW-WT), and the binary additive two-way wire-tap channel, (BATW-WT).

Arlo U. Landolt

UBVRI photoelectric observations have been made of 109 stars around the sky, centered more or less at -50 degrees declination. The majority of the stars fall in the magnitude range 10.4 < V < 15.5 and in the color index range -0.33 < (B - V) < +1.66. These new broadband photometric standard stars average 16.4 measurements each from data taken on 116 differen

Satoshi Miyashita, Kenji Yonemitsu

Combined effects of electron correlations and lattice distortions are investigated on the charge ordering in θ-(BEDT-TTF)2RbZn(SCN)4 theoretically in a two-dimensional 3/4-filled extended Hubbard model with electron-lattice couplings. It is known that this material undergoes a phase transition from a high-symmetry metallic state to a low-symmetry insulating

Arlo U. Landolt, Alan K. Uomoto

Photoelectric data on the Johnson-Kron-Cousins UBVRI broadband photometric system are provided for a set of stars which have been used as spectrophotometric standard stars at the Hubble Space Telescope.

M. B. Voloshin

The $D {\bar D}^*$ scattering amplitude and the production of the final states $π^+ π^- J/ψ$ and $π^+ π^- π^0 J/ψ$ near the $D^0 {\bar D}^{*0}$ threshold are discussed following the recent suggestion that the observed peaks X(3872) and X(3875) in the decays $B \to X K$ are due to a virtual state $X$ in the $D^0 {\bar D}^{*0}$ channel. The strong interaction

Daniel Burgarth, Vittorio Giovannetti

We demonstrate a scheme for controlling a large quantum system by acting on a small subsystem only. The local control is mediated to the larger system by some fixed coupling Hamiltonian. The scheme allows to transfer arbitrary and unknown quantum states from a memory on the large system (``upload access&#39;&#39;) as well as the inverse (``download access&#3

K. B. W. McQuinn, Charles E. Woodward, S. P. Willner, E. F. Polomski

We analyze five epochs of Spitzer Space Telescope/Infrared Array Camera (IRAC) observations of the nearby spiral galaxy M33. Each epoch covered nearly a square degree at 3.6, 4.5, and 8.0 microns. The point source catalog from the full dataset contains 37,650 stars. The stars have luminosities characteristic of the asymptotic giant branch and can be separate

David Ehrenreich, Arnaud Cassan

Light and cold extrasolar planets such as OGLE 2005-BLG-390Lb, a 5.5 Earth-mass planet detected via microlensing, could be frequent in the Galaxy according to some preliminary results from microlensing experiments. These planets can be frozen rocky- or ocean-planets, situated beyond the snow line and, therefore, beyond the habitable zone of their system. The

Marc Wagner

The pseudoparticle approach is a numerical technique to compute path integrals without discretizing spacetime. The basic idea is to integrate over those field configurations, which can be represented by a sum of a fixed number of localized building blocks (pseudoparticles). In a couple of previous papers we have successfully applied the pseudoparticle approa

Mark Pankov

Let $H$ be a separable complex Hilbert space. Denote by ${\mathcal G}_{\infty}(H)$ the Grassmannian consisting of closed linear subspaces with infinite dimension and codimension. This Grassmannian is partially ordered by the inclusion relation. We show that every continuous order preserving bijective transformation of ${\mathcal G}_{\infty}(H)$ is induced by

Gerrit L. Verschuur

Interstellar neutral hydrogen (HI) emission spectra manifest several families of linewidths whose numerical values (34, 13 & 6 km/s) appear to be related to the critical ionization velocities (CIVs) of the most abundant interstellar atomic species. Extended new analysis of HI emission profiles shows that the 34 km/s wide component, probably corresponding to

Oliver Henkel

In this paper non-group permutation modulated sequences for the Gaussian channel are considered. Without the restriction to group codes rather than subsets of group codes, arbitrary rates are achievable. The code construction utilizes the known optimal group constellations to ensure at least the same performance but exploit the Gray code ordering structure o

Bing Wang

Along a Ricci flow solution on a closed manifold, we show that if Ricci curvature is uniformly bounded from below, then a scalar curvature integral bound is enough to extend flow. Moreover, this integral bound condition is optimal in some sense.

I. Abt, A. Caldwell, K. Kröninger, J. Liu

Experiments built to search for neutrinoless double beta-decay are limited in their sensitivity not only by the exposure but also by the amount of background encountered. Radioactive isotopes in the surrounding of the detectors which emit gamma-radiation are expected to be a significant source of background in the GERmanium Detector Array, GERDA. Methods to

T. Verdugo, J. A. de Diego, M. Limousin

We present the first strong lensing study of the mass distribution in the cluster MS 2053-04 based on HST archive data. This massive, X-ray luminous cluster has a redshift z=0.583, and it is composed of two structures that are gravitationally bound to each other. The cluster has one multiply imaged system constituted by a double gravitational arc. We have pe

C. Andreeva, A. Atvars, M. Auzinsh, K. Bluss

Experimental and theoretical studies are presented related to the ground-state magneto-optical resonance prepared in Cesium vapour confined in an Extremely Thin Cell (ETC, with thickness equal to the wavelength of the irradiating light). It is shown that the utilization of the ETC allows one to examine the formation of a magneto-optical resonance on the indi

V. Quilis, A. C. González-García, D. Sáez, J. A. Font

We discuss the emission of gravitational radiation produced in encounters of dark matter galactic halos. To this aim we perform a number of numerical simulations of typical galaxy mergers, computing the associated gravitational radiation waveforms as well as the energy released in the processes. Our simulations yield dimensionless gravitational wave amplitud

I. Jimenez-Serra, J. Martin-Pintado, A. Rodriguez-Franco, C. Chandler

We present VLA and PdBI subarcsecond images (0.15&#34;-0.6&#34;) of the radiocontinuum emission at 7 mm and of the SO2 J=19_{2,18}-18_{3,15} and J=27_{8,20}-28_{7,21} lines toward the Cepheus A HW2 region. The SO2 images reveal the presence of a hot core internally heated by an intermediate mass protostar, and a circumstellar rotating disk around the HW2 rad

Yasser Roudi, Peter E. Latham

A fundamental problem in neuroscience is understanding how working memory -- the ability to store information at intermediate timescales, like 10s of seconds -- is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite al

Yuri A. Rylov

The space-time geometry is considered to be a physical geometry, i.e. a geometry described completely by the world function. All geometrical concepts and geometric objects are taken from the proper Euclidean geometry. They are expressed via the Euclidean world function σ_E and declared to be concepts and objects of any physical geometry, provided the Euclide

Vladimir V. Vershinin

Inverse braid monoid describes a structure on braids where the number of strings is not fixed. So, some strings of initial $n$ may be deleted. In the paper we show that many properties and objects based on braid groups may be extended to the inverse braid monoids. Namely we prove an inclusion into a monoid of partial monomorphisms of a free group. This gives

Kathrin A. Hochmuth, Manfred Lindner, Georg G. Raffelt

In scintillator detectors, the forward displacement of the neutron in the reaction $\barν_e+p\to e^++n$ provides neutrino directional information as demonstrated by the CHOOZ reactor experiment with 2,500 events. The near detector of the forthcoming Double Chooz experiment will collect $1.6\times10^5$ events per year, enough to determine the average neutrino

Andrea Banfi, Gavin P. Salam, Giulia Zanderighi

Heavy-quark jets are important in many of today&#39;s collider studies and searches, yet predictions for them are subject to much larger uncertainties than for light jets. This is because of strong enhancements in higher orders from large logarithms, ln(p_t/m_Q). We propose a new definition of heavy-quark jets, which is free of final-state logarithms to all

O. C. Winter, R. de la Reza, R. C. Domingos, L. A. G. Boldrin

The photospheres of stars hosting planets have larger metallicity than stars lacking planets. In the present work we study the possibility of an earlier metal enrichment of the photospheres by means of impacting planetesimals during the first 20-30Myr. Here we explore this contamination process by simulating the interactions of an inward migrating planet wit

A. Grünrock, S. Herr

The Cauchy problem for the derivative nonlinear Schrödinger equation with periodic boundary condition is considered. Local well-posedness for periodic initial data u_0 in the space ^H^s_r, defined by the norms ||u_0||_{^H^s_r}=||<xi>^s ^u_0||_{l^r&#39;} is shown in the parameter range s>= 1/2, 2>r>4/3. The proof is based on an adaptation of the gauge transfo

D. Froebrich, G. C. Murphy, M. D. Smith, J. Walsh

We present a 127deg x 63deg extinction map of the Anticenter of the Galaxy, based on <J-H> and <H-K> colour excess maps from 2MASS. This 8001 square degree map with a resolution of 4 arcminutes is provided as online material. The colour excess ratio <J-H> / <H-K> is used to determine the power law index of the reddening law (β) for individual regions contain

A. M. Jayannavar, Mamata Sahoo

We study Langevin dynamics of a driven charged particle in the presence as well as in the absence of magnetic field. We discuss the validity of various work fluctuation theorems using different model potentials and external drives. We also show that one can generate an orbital magnetic moment in a nonequilibrium state which is absent in equilibrium.

Jun Lu, De-An Pan, Lijie Qiao

This letter presents principles and applications of a virtual multi-channel lock-in amplifier that is a simple but effective method to recover small ac signal from noise with high presison. The fundamentals of this method are based on calculation of cross-correlation function. Via this method, we successfully built up a magnetoelectric measurement system whi

Fani Petalidou

We study the geometric quantization process for twisted Poisson manifolds. First, we introduce the notion of Lichnerowicz-twisted Poisson cohomology for twisted Poisson manifolds and we use it in order to characterize their prequantization bundles and to establish their prequantization condition. Next, we introduce a polarization and we discuss the quantizat

Gabor Ivanyos

An important subcase of the hidden subgroup problem is equivalent to the shift problem over abelian groups. An efficient solution to the latter problem would serve as a building block of quantum hidden subgroup algorithms over solvable groups. The main idea of a promising approach to the shift problem is reduction to solving systems of certain random disequa

Mariana M. Odashima, K. Capelle

Density-functional theory requires ever better exchange-correlation (xc) functionals for the ever more precise description of many-body effects on electronic structure. Universal constraints on the xc energy are important ingredients in the construction of improved functionals. Here we investigate one such universal property of xc functionals: the Lieb-Oxfor

Hong-Jian Feng, Fa-Min Liu

First principles calculations were performed to study the ground state electronic properties of BaFeO3 (BFO) within the density functional theory (DFT). Adopting generalized gradient approximation (GGA) exchange and correlation functional and Vosko-Wilk-Nusair correlation energy functional interpolation, we have systematically conducted the band structure, d

Gianni Dal Maso, Antonio DeSimone, Maria Giovanna Mora, Massimiliano Morini

We study a relaxed formulation of the quasistatic evolution problem in the context of small strain associative elastoplasticity with softening. The relaxation takes place in spaces of generalized Young measures. The notion of solution is characterized by the following properties: global stability at each time and energy balance on each time interval. An exam

Michele Pestalozzi

In this contribution I will attempt to show that the study of galactic 6.7 and 12.2GHz methanol masers themselves, as opposed to the use of methanol masers as signposts, can yield important conclusions contributing to the understanding of high-mass star formation. Due to their exclusive association with star formation, methanol masers are the best tools to d

Geoffrey Grimmett, Tobias Osborne, Petra Scudo

We study the asymptotic scaling of the entanglement of a block of spins for the ground state of the one-dimensional quantum Ising model with transverse field. When the field is sufficiently strong, the entanglement grows at most logarithmically in the number of spins. The proof utilises a transformation to a model of classical probability called the continuu

J. M. Aguiar-Hualde, G. Chiappe, E. Louis, E. V. Anda

The Kondo effect observed in recent STM experiments on transport through CoPc and TBrPP-Co molecules adsorbed on Au(111) and Cu(111) surfaces, respectively, is discussed within the framework of a simple model (Phys. Rev. Lett. {\bf 97}, 076806 (2006)). It is shown that, in the Kondo regime and by varying the adequate model parameters, it is possible to produ

Zin Arai

We prove John Hubbard&#39;s conjecture on the topological complexity of the hyperbolic horseshoe locus of the complex Hénon map. Indeed, we show that there exist several non-trivial loops in the locus which generate infinitely many mutually different monodromies. Our main tool is a rigorous computational algorithm for verifying the uniform hyperbolicity of c

Kostya Trachenko, Vadim Brazhkin

We discuss two main universal dynamic crossovers in a liquid that correspond to relaxation times of 1 ps and $10^{-7}-10^{-6}$ s. We introduce the concept of liquid elasticity length $d_{el}$. At room temperature, $d_{el}$ is several Åin water and increases to 0.01 mm in honey and 1 mm in tar. We show that on temperature decrease, $d_{el}$ crosses the fundam

Pablo San-Jose, Gerd Schön, Alexander Shnirman, Gergely Zarand

We investigate relaxation and dephasing of an electron spin confined in a semiconductor quantum dot and subject to spin-orbit coupling. Even in vanishing magnetic field, B = 0, slow noise coupling to the electron&#39;s orbital degree of freedom leads to dephasing of the spin due to a random, in general non-Abelian Berry phase acquired by the spin. For illust

E. G. Batyev

A state of an excitonic insulator with the electric current is studied. Initially, in the metallic phase, the electrons and holes are assumed to be moving in the opposite directions, so as the electric current exists. This state is supported by an external condition (the specimen is in an electric circuit with the current). When the temperature decreases, th