January 2009 arXiv papers — page 7

Stefan Gunther, Karsten Kruse

Mechanical oscillations are important for many cellular processes, e.g. the beating of cilia and flagella or the sensation of sound by hair cells. These dynamic states originate from spontaneous oscillations of molecular motors. A particularly clear example of such oscillations has been observed in muscle fibers under non-physiological conditions. In that ca

R. Lutz, S. Schuh, R. Silvotti, R. Kruspe

Pulsating subdwarf B (sdB) stars oscillate in short-period p-modes or long-period g-modes. HS0702+6043 (DW Lyn) is one of a few objects to show characteristics of both types and is hence classified as hybrid pulsator. It is one of our targets in the EXOTIME program to search for planetary companions around extreme horizontal branch objects. In addition to th

Jonghyun Go, Muhammad A. Alam

Over the last decade, many experiments have demonstrated that nanobiosensors based on Nanotubes and Nanowires are significantly more sensitive compared to their planar counterparts. Yet, there has been persistent gap between reports of analyte detection at ~femto-Molar concentration and theory suggesting the impossibility of sub-pM detection at the correspon

Alyssa Gilbert, Paul Wiegert

The Canada-France-Hawaii Telescope Legacy Survey, specifically the Very Wide segment of data, is used to search for possible main-belt comets. In the first data set, 952 separate objects with asteroidal orbits within the main-belt are examined using a three-level technique. First, the full-width-half-maximum of each object is compared to stars of similar mag

M. A. Jafarizadeh, K. Aghayar, A. Heshmati

A generic algorithm is developed to reduce the problem of obtaining linear and nonlinear entanglement witnesses of a given quantum system, to convex optimization problem. This approach is completely general and can be applied for the entanglement detection of any N-partite quantum system. For this purpose, a map from convex space of separable density matrice

Bent Orsted, Joseph A. Wolf

Let $G_0$ be a connected, simply connected real simple Lie group. Suppose that $G_0$ has a compact Cartan subgroup $T_0$, so it has discrete series representations. Relative to $T_0$ there is a distinguished positive root system $Δ^+$ for which there is a unique noncompact simple root $ν$, the "Borel -- de Siebenthal system". There is a lot of fascin

Dmitry Bolotov, Alexander Dranishnikov

We prove the Gromov conjecture on the macroscopic dimension of the universal covering of a closed spin manifold with a positive scalar curvature under the following assumptions on the fundamental group: 1. The Strong Novikov Conjecture holds for $π$. 2. The natural map $per:ko_n(Bπ)\to KO_n(Bπ)$ is injective.

D. Ardouin, A. Belletoile, C. Berat, D. Breton

The new setup of the CODALEMA experiment installed at the Radio Observatory in Nancay, France, is described. It includes broadband active dipole antennas and an extended and upgraded particle detector array. The latter gives access to the air shower energy, allowing us to compute the efficiency of the radio array as a function of energy. We also observe a la

Thierry C. Petit Lobão, Pedro G. S. Cardoso, Suani T. R. Pinho, Ernesto P. Borges

Nonextensive statistical mechanics has been a source of investigation in mathematical structures such as deformed algebraic structures. In this work, we present some consequences of $q$-operations on the construction of $q$-numbers for all numerical sets. Based on such a construction, we present a new product that distributes over the $q$-sum. Finally, we pr

The DELPHI Collaboration, J. Abdallah

The production of two high-p_T jets in the interactions of quasi-real photons in e+e- collisions at sqrt{s_ee} from 189 GeV to 209 GeV is studied with data corresponding to an integrated e+e- luminosity of 550 pb^{-1}. The jets reconstructed by the k_T cluster algorithm are defined within the pseudo-rapidity range -1 < eta < 1 and with jet transverse momentu

S. Gepraegs, F. D. Czeschka, M. Opel, S. T. B. Goennenwein

The double perovskite Sr2CrReO6 is an interesting material for spintronics, showing ferrimagnetism up to 635 K with a predicted high spin polarization of about 86%. We fabricated Sr2CrReO6 epitaxial films by pulsed laser deposition on (001)-oriented SrTiO3 substrates. Phase-pure films with optimum crystallographic and magnetic properties were obtained by gro

Andreas Brett, Andreas Leicher

Ethemba provides a framework and demonstrator for TPM applications.

R. Kissmann, J. Kleimann, H. Fichtner, R. Grauer

In this paper we show results of numerical simulations for the turbulence in the interstellar medium. These results were obtained using a Riemann solver-free numerical scheme for high-Mach number hyperbolic equations. Here we especially concentrate on the physical properties of the ISM. That is, we do not present turbulence simulations trimmed to be applicab

Amaël Broustet, Gianluca Pacienza

It is well known that a smooth projective Fano variety is rationally connected. Recently Zhang (and later Hacon and McKernan as a special case of their work on the Shokurov RC-conjecture) proved that the same conclusion holds for a klt pair $(X,\D)$ such that $-(K_X+\D)$ is big and nef. We prove here a natural generalization of the above result by dropping t

Y. Gomez, D. Tafoya, G. Anglada, L. F. Miranda

K 3-35 is a planetary nebula (PN) where H2O maser emission has been detected, suggesting that it departed from the proto-PNe phase only some decades ago. Interferometric VLA observations of the OH 18 cm transitions in K~3-35 are presented.OH maser emission is detected in all four ground state lines (1612, 1665, 1667, and 1720 MHz). All the masers appear blue

Augusto C. Ponce, Jean Van Schaftingen

For every $2 < p < 3$, we show that $u \in W^{1,p}(B^3; S^2)$ can be strongly approximated by maps in $C^\infty(\Bar{B}^3; S^2)$ if, and only if, the distributional Jacobian of $u$ vanishes identically. This result was originally proved by Bethuel-Coron-Demengel-Helein, but we present a different strategy which is motivated by the $W^{2,p}$-case.

Luigi Mancini

We discuss whether the Gaussian is a reasonable approximation of the velocity distribution of stellar systems that are not spherically distributed. By using a non-Gaussian velocity distribution to describe the sources in the Large Magellanic Cloud (LMC), we reinvestigate the expected microlensing parameters of a lens population isotropically distributed eith

Georges Meynet, Sylvia Ekstrom, Cyril Georgy, Cristina Chiappini

Massive stars are &#34;cosmic engines&#34; (cf the title of the IAU Symposium 250). They drive the photometric and chemical evolution of galaxies, inject energy and momentum through stellar winds and supernova explosions, they modify in this way the physical state of the interstellar gas and have an impact on star formation. The evolution of massive stars de

The DELPHI Collaboration, J. Abdallah

Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) in dimuon events at LEP1 were studied in two photon kinematic ranges: 0.2 < E_gamma <= 1 GeV and transverse momentum with respect to the parent muon p_T < 40 MeV/c, and 1 < E_gamma <= 10 GeV and p_T < 80 MeV/c . A good agreement of the observed photon rate with predictions from Q

O. S. Barisic, P. Prelovsek, A. Metavitsiadis, X. Zotos

The effect of a single static impurity on the many-body states and on the spin and thermal transport in the one-dimensional anisotropic Heisenberg chain at finite temperatures is studied. Whereas the pure Heisenberg model reveals Poisson level statistics and dissipationless transport due to integrability, we show using the numerical approach that a single im

DELPHI Collaboration, J. Abdallah

Single photons detected by the DELPHI experiment at LEP2 in the years 1997-2000 are reanalysed to investigate the existence of a single extra dimension in a modified ADD scenario with slightly warped large extra dimensions. The data collected at centre-of-mass energies between 180 and 209 GeV for an integrated luminosity of ~650 pb^{-1} agree with the predic

Fabio Antonini, Roberto Capuzzo-Dolcetta, David Merritt

Self-consistent solutions for triaxial mass models are highly non-unique. In general, some of these solutions might be dynamically unstable, making them inappropriate as descriptions of steady-state galaxies. Here we demonstrate for the first time the existence in triaxial galaxy models of an instability similar to the radial-orbit instability of spherical m

D. W. Higinbotham

The nuclear physics experiments at the Thomas Jefferson National Accelerator Facility often require longitudinally polarized electrons to be simultaneously delivered to three experimental halls. The degree of longitudinal polarization to each hall varies as function of the accelerator settings, making it challenging in certain situations to deliver a high de

David Blázquez-Sanz

Weil algebra morphism induce natural transformations between Weil bundles. In some well known cases, a natural transformation is endowed with a canonical structure of affine bundle. We show that this structure arises only when the Weil algebra morphism is surjective and its kernel has null square. Moreover, in some cases, this structure of affine bundle is p

S. N. Coppersmith, P. U. P. A. Gilbert, R. A. Metzler

Nacre, commonly known as mother-of-pearl, is a remarkable biomineral that in red abalone consists of layers of 400-nm thick aragonite crystalline tablets confined by organic matrix sheets, with the $(001)$ crystal axes of the aragonite tablets oriented to within $\pm$ 12 degrees from the normal to the layer planes. Recent experiments demonstrate that this or

Sorin Dumitrescu

We classify complex compact parallelizable manifolds which admit flat torsion free holomorphic affine connections. We exhibit complex compact manifolds admitting holomorphic affine connections, but no flat torsion free holomorphic affine connections.

David Blázquez-Sanz, Juan José Morales-Ruiz

In this paper we develop a differential Galois theory for algebraic Lie-Vessiot systems in algebraic homogeneous spaces. Lie-Vessiot systems are non autonomous vector fields that are linear combinations with time-dependent coefficients of fundamental vector fields of an algebraic Lie group action. Those systems are the building blocks for differential equati

David Blázquez-Sanz, Juan José Morales-Ruiz

This paper is dedicated to the differential Galois theory in the complex analytic context for Lie-Vessiot systems. Those are the natural generaliza- tion of linear systems, and the more general class of differential equations adimitting superposition laws, as recently stated in [5]. A Lie-Vessiot sys- tem is automatically translated into a equation in a Lie

A. V. Dodonov, S. S. Mizrahi

Recently Parigi et al. [Science 317, 1890 (2007)] implemented experimentally the photon subtraction and addition processes from/to a light field in a conditional way, when the required operations were produced successfully only upon the positive outcome of a separate measurement. It was verified that for a low intensity beam (quantum regime) the bosonic anni

J. Piekarewicz

Understanding the equation of state (EOS) of cold nuclear matter, namely, the relation between the pressure and energy density, is a central goal of nuclear physics that cuts across a variety of disciplines. Indeed, the limits of nuclear existence, the collision of heavy ions, the structure of neutron stars, and the dynamics of core-collapse supernova, all d

M. Gooch, B. Lv, J. H. Tapp, Z. Tang

The effect of hydrostatic pressure on the superconductivity in LiFeAs is investigated up to 1.8 GPa. The superconducting transition temperature, T_c, decreases linearly with pressure at a rate of 1.5 K/GPa. The negative pressure coefficient of T_c and the high ambient pressure T_c indicate that LiFeAs is the high-pressure analogue of the isoelectronic SrFe_2

Andrew Adamatzky

Plasmodium of \emph{Physarum polycephalum} is a single huge (visible by naked eye) cell with myriad of nuclei. The plasmodium is a promising substrate for non-classical, nature-inspired, computing devices. It is capable for approximation of shortest path, computation of planar proximity graphs and plane tessellations, primitive memory and decision-making. Th

S. L. Casewell, P. D. Dobbie, R. Napiwotzki, M. R. Burleigh

We present the results of a high resolution optical spectroscopic study of nine white dwarf candidate members of Praesepe undertaken with the VLT and UVES. We find, contrary to a number of previous studies, that WD0836+201 (LB390, EG59) and WD0837+199 (LB393, EG61) are magnetic and non-magnetic white dwarfs respectively. Subsequently, we determine the radial

Peter Constantin, Gregory Seregin

We provide a proof of global regularity of solutions of coupled Navier-Stokes equations and Fokker-Planck equations, in two spatial dimensions, in the absence of boundaries. The proof yields a priori estimates for the growth of spatial gradients.

DELPHI Collaboration, J. Abdallah

Measurements are presented of R_b, the ratio of the b bbar cross-section to the q qbar cross-section in e+e- collisions, and the forward-backward asymmetry A^b_FB at twelve energy points in the range sqrt(s) = 130-207 GeV. These results are found to be consistent with the Standard Model expectations. The measurements are used to set limits on new physics sce

Jochen Bröcker

Logistic models are studied as a tool to convert output from numerical weather forecasting systems (deterministic and ensemble) into probability forecasts for binary events. A logistic model obtains by putting the logarithmic odds ratio equal to a linear combination of the inputs. As any statistical model, logistic models will suffer from over-fitting if the

P. Di Vecchia, A. Liccardo, R. Marotta, F. Pezzella

We use both a string and a field theoretical approach in order to determine respectively the Kaehler metrics of untwisted and twisted open strings attached to magnetized D9 branes in toroidal compactifications.

J. A. Ballin, P. D. Dauncey, A. -M. Magnan, M. Noy

Progress is reported on the development and testing of Monolithic Active Pixel Sensors (MAPS) for a Si-W ECAL for the ILC. Using laser and source setups, a first version of the sensor has been characterised through measurements of the absolute gain calibration, noise and pedestal. The pixel-to-pixel gain spread is 10%. Charge diffusion has been measured and

Jean-Christophe Breton, Ivan Nourdin, Giovanni Peccati

In this short note, we show how to use concentration inequalities in order to build exact confidence intervals for the Hurst parameter associated with a one-dimensional fractional Brownian motion

Theodoros Diakonidis

A complete analytical reduction of general one-loop Feynman integrals with five legs for tensors up to rank R=3 and six legs for tensors up to rank 4 is reviewed. An elegant formalism with extensive use of signed minors was developed for the cancellation of leading inverse Gram determinants.The resulting compact formulae allow both for a study of analytical

Balázs Dóra, Ferenc Simon

The temperature dependence of the electron spin life-time, T_1 and the g-factor are anomalous in alkali fullerides (K,Rb)_3C_60, which cannot be explained by the canonical Elliott-Yafet theory. These materials are archetypes of strongly correlated and narrow band metals. We introduce the concept of &#34;complex electron spin resonance frequency shift&#34; to

Lukas Jahnke, Jan W. Kantelhardt, Richard Berkovits

We numerically show that very small magnetic flux can significantly shift the metal-insulator transition point in a disordered electronic system. The shift we observe for the 3d Anderson model obeys a power law as predicted by Larkin and Khmel&#39;nitskii (1981). We compute the exponent and find good agreement with the prediction. However, the power law hold

Elena Dubrova, Maxim Teslenko

This paper addresses the problem of finding cycles in the state transition graphs of synchronous Boolean networks. Synchronous Boolean networks are a class of deterministic finite state machines which are used for the modeling of gene regulatory networks. Their state transition graph cycles, called attractors, represent cell types of the organism being model

C. P. Kwong

The mathematical model proposed by George Soros for his theory of reflexivity is analyzed under the framework of discrete dynamical systems. We show the importance of the notion of fixed points for explaining the behavior of a reflexive system governed by its cognitive and manipulative functions. The interrelationship between these two functions induces fixe

Barbara Ercolano, Cathie J. Clarke, Thomas P. Robitaille

We re-examine the recent suggestion of a high fraction of transition discs (i.e. those with a cleared inner hole) in M stars, motivated by the fact that we expect that, for M stars, even discs without inner holes should exhibit very weak excess shortward of around 10um. Our analysis of spectral energy distribution models suggest that this indeed means that M

Alexander V. Gnedin

Theory of Kingman&#39;s partition structures has two culminating points: the general paintbox representation, relating finite partitions to hypothetical infinite populations via a natural sampling procedure, known as Kingman&#39;s paintbox; a central example of the theory - the Ewens-Pitman two-parameter family of partitions. In these notes we further develo

Eduardo Guendelman, Alexander Kaganovich, Emil Nissimov, Svetlana Pacheva

We first briefly present a consistent world-volume Lagrangian description of lightlike p-branes (LL-branes) in two equivalent forms - a Polyakov-type and a dual to it Nambu-Goto-type formulations. The most important characteristic features of LL-brane dynamics are: (i) the brane tension appears as a non-trivial additional dynamical degree of freedom; (ii) co

A. Karmakar, S. Majumdar, S. Patnaik, S. Giri

Bulk dc resistivity and dielectric constant measurements with temperature and frequency have been performed in LaMn_{1-x}Fe_xO_3 (0 <= x <= 1.0) as a result of Fe substitution both for the as-synthesized and oxygen annealed samples. Temperature dependence of real part of dielectric constant at different frequencies show a frequency and temperature independen

Attila Szallas, Anuradha Jagannathan, Stefan Wessel

We examine a novel type of disorder in quantum antiferromagnets. Our model consists of localized spins with antiferromagnetic exchanges on a bipartite quasiperiodic structure, which is geometrically disordered in such a way that no frustration is introduced. In the limit of zero disorder, the structure is the perfect Penrose rhombus tiling. This tiling is pr

O. Shekhovtsova, G. Venanzoni, G. Pancheri

FASTERD is a Monte Carlo event generator to study the final state radiation both in the $e^+e^-\toπ^+π^-γ$ and $e^+e^-\toπ^0π^0γ$ processes in the energy region of the $ϕ$-factory DA$Φ$NE. Differential spectra that include both initial and final state radiation and the interference between them are produced. Three different mechanisms for the $ππγ$ final sta

Franz Kreupl, Rainer Bruchhaus, Petra Majewski, Jan B. Philipp

We propose carbon as new resistive memory material for non-volatile memories and compare three allotropes of carbon, namely carbon nanotubes, graphene-like conductive carbon and insulating carbon for their possible application as resistance-change material in high density non-volatile memories. Repetitive high-speed switching and the potential for multi-leve

Ashok Razdan

Energy positions of pure magnetic transitions in Mossbauer Spectroscopy are calculated using non-extensive approach. It is observed that these new calculated energy positions so obtained, may have strong overlap with those energy positions obtained from combined effect of magnetic and quadrupole interactions using standard statistical physics.

Atsushi Miyake, Alain Villaume, Yoshinori Haga, Georg Knebel

The itinerant quasi-ferromagnetic metal MnSi has been studied by detailed thermal expansion measurements under pressures and magnetic fields. A sudden decrease of the volume at the critical pressure Pc ~1.6 GPa has been observed and is in good agreement with the pressure variation of the volume fraction of the spiral magnetic ordering. This confirms that the

Sebastien Fromang, Richard P. Nelson

The aim of this paper is to study the vertical profile of small dust particles in protoplanetary discs in which angular momentum transport is due to MHD turbulence driven by the magnetorotational instability. We consider particle sizes that range from approximately 1 micron up to a few millimeters.We use a grid--based MHD code to perform global two-fluid sim

Vojtech Zadnik

Lie contact structures generalize the classical Lie sphere geometry of oriented hyperspheres in the standard sphere. They can be equivalently described as parabolic geometries corresponding to the contact grading of orthogonal real Lie algebra. It follows the underlying geometric structure can be interpreted in several equivalent ways. In particular, we show

C. Bonati, G. Cossu, A. D&#39;Alessandro, M. D&#39;Elia

The Higgs SU(2) model with fixed Higgs length is usually believed to have two different phases at high gauge coupling (β), separated by a line of first order transitions but not distinuguished by any typical symmetry associated with a local order parameter, as first proved by Fradkin and Shenker. We show that in regions of the parameter space where it is usu

Danilo Puggioni, Alessio Filippetti, Vincenzo Fiorentini

We study the Fermi surface of metallic, non-magnetic \textit{ortho}-II YBa$_2$Cu$_3$O$_{6.5}$ using three different density-functional-based band-structure techniques (GGA, GGA+U, PSIC). The calculated Fermi surface exhibits no pockets in GGA+U and PSIC, a minor one in GGA. Upon shifting the Fermi level in the vicinity of the calculated value, we instead obs

J. M. G. Calcines, L. Vandembroucq

Based on a Whitehead-type characterization of the sectional category we develop the notion of weak sectional category. This is a new lower bound of the sectional category, which is inspired by the notion of weak category in the sense of Berstein-Hilton. We establish several properties and inequalities, including the fact that the weak sectional category is a

Xavier Brokmann, Lisa Marshall, Moungi Bawendi

We show that the single emitter linewidth underlying a broadened ensemble emission spectrum can be extracted from correlations among the stochastic intensity fluctuations in the ensemble spectrum. Spectral correlations can be observed at high temporal and spectral resolutions with a cross-correlated pair of avalanche photodiodes placed at the outputs of a sc

V. Giovannetti, S. Montangero, M. Rizzi, R. Fazio

Homogeneous Multi-scale Entanglement Renormalization Ansazt (MERA) state have been recently introduced to describe quantum critical systems. Here we present an extensive analysis of the properties of such states by clarifying the definition of their transfer super-operator whose structure is studied within a informational theoretical approach. Explicit expre

M. Grigorescu

Elements of a restricted variational approach to the nuclear mean-field dynamics, providing the microscopic structure of the low energy collective modes, are summarized. The results are illustrated for the isovector states produced by the proton-neutron interactions in deformed and superfluid nuclei.

Kamalesh Kumar Sharma

The channel capacity theorem for additive white Gaussian noise channel (AWGN), widely known as the Shannon-Hartley Law, expresses the information capacity of a channel bandlimited in the conventional Fourier domain in terms of the signal-to-noise ratio in it. In this letter generalized versions of the Shannon-Hartley Law using the linear canonical transform

B. Miszalski, A. Acker, A. F. J. Moffat, Q. A. Parker

Binarity has been hypothesised to play an important, if not ubiquitous, role in the formation of planetary nebulae (PNe). Yet there remains a severe paucity of known binary central stars required to test the binary hypothesis and to place strong constraints on the physics of the common-envelope (CE) phase of binary stellar evolution. Large photometric survey

C. Richardt, G. Anton, K. Graf, J. Hoessl

This article focuses on techniques for position reconstruction of acoustic point sources with the AMADEUS setup consisting of 36 acoustic sensors in the Mediterranean Sea. The direction reconstruction of an acoustic point source utilizes the information of the 6 small-volume hydrophone clusters of AMADEUS individually. Source position reconstruction is then

Katsunori Kubo

To understand effects of orbital degeneracy on magnetism, in particular effects of Hund&#39;s rule coupling, we study the two-orbital Hubbard model on a square lattice by a variational Monte Carlo method. As a variational wave function, we consider a Gutzwiller projected wave function for a staggered spin and/or orbital ordered state. We find a ferromagnetic

Peter Baxendale, Georgi Dimitroff

We study some finite time transport properties of isotropic Brownian flows. Under a certain nondegeneracy condition on the potential spectral measure, we prove that uniform shrinking or expansion of balls under the flow over some bounded time interval can happen with positive probability. We also provide a control theorem for isotropic Brownian flows with dr

Nasser Metwally

The sensitivity of entanglement to the thermal and squeezed reservoirs&#39; parameters is investigated regarding entanglement decay and what is called sudden-death of entanglement, ESD, for a system of two qubit pairs. The dynamics of information is investigated by means of the information disturbance and exchange information. We show that for squeezed reser

K. Bernot, J. Luzon, A. Caneschi, D. Gatteschi

We investigate theoretically and experimentally the static magnetic properties of single crystals of the molecular-based Single-Chain Magnet (SCM) of formula [Dy(hfac)$_{3}$NIT(C$_{6}$H$_{4}$OPh)]$_{\infty}$ comprising alternating Dy$^{3+}$ and organic radicals. A peculiar inversion between maxima and minima in the angular dependence of the magnetic molar su

Adem Kilicman, Zabidin Salleh

In this paper we introduce and study the notion of pairwise weakly Lindelof bitopological spaces and obtain some results. Further, we also study the pairwise weakly Lindelof subspaces and subsets, investigate some of their properties and show that a pairwise weakly Lindelof property is not a hereditary property.

Peter Horan, John Carminati

Prime-based ordering which is proved to be admissible, is the encoding of indeterminates in power-products with prime numbers and ordering them by using the natural number order. Using Eiffel, four versions of Buchberger&#39;s improved algorithm for obtaining Groebner Bases have been developed: two total degree versions, representing power products as string

Akihiro Suzuki, Toshikazu Shigeyama

We present results of a 2D3V kinetic Vlasov simulation of the Weibel instability. The kinetic Vlasov simulation allows us to investigate the velocity distribution of dilute plasmas, in which the effect of collisions between particles is negligible, and has the advantage that the accuracy of the calculated velocity distribution does not depend on the density

E. Colberg, A. M. de Jesus, K. Kinneberg, G. Silva Neto

In 1968, Simons introduced the concept of index for hypersurfaces immersed into the Euclidean sphere S^{n+1}. Intuitively, the index measures the number of independent directions in which a given hypersurface fails to minimize area. The earliest results regarding the index focused on the case of minimal hypersurfaces. Many such results established lower boun

R. L. Dewar, J. C. -C. Yap

In this paper we calculate and visualize the dynamics of an ensemble of electrons trapping in an electrostatic wave of slowly increasing amplitude, illustrating that, despite disordering of particles in angle during the trapping transition as they pass close to X-points, there is still an adiabatic invariant for the great majority of particles that allows th

Hai-Yang Cheng, Jim Smith

We give an overview of the experimental measurements and the theoretical understanding of the branching fractions and CP-violating asymmetries of charmless B-meson decays. Most experimetal results are from the BABAR and Belle experiments during the past decade. The global features of these experimental results are typically well described by the QCD-motivate

Andrew W. Howard, John A. Johnson, Geoffrey W. Marcy, Debra A. Fischer

We report the discovery of the first low-mass planet to emerge from the NASA-UC Eta-Earth Program, a super-Earth orbiting the K0 dwarf HD 7924. Keplerian modeling of precise Doppler radial velocities reveals a planet with minimum mass M_P sin i = 9.26 M_Earth in a P = 5.398 d orbit. Based on Keck-HIRES measurements from 2001 to 2008, the planet is robustly d

Mark Holmes

We study a random walk that has a drift $\fracβ{d}$ to the right when located at a previously unvisited vertex and a drift $\fracμ{d}$ to the left otherwise. We prove that in high dimensions, for every $μ$, the drift to the right is a strictly increasing and continuous function of $β$, and that there is precisely one value $β_0(μ,d)$ for which the resulting

Iain M Johnstone, Arthur Yu Lu

Principal components analysis (PCA) is a classical method for the reduction of dimensionality of data in the form of n observations (or cases) of a vector with p variables. For a simple model of factor analysis type, it is proved that ordinary PCA can produce a consistent (for n large) estimate of the principal factor if and only if p(n) is asymptotically of

Z. Pluhar, H. A. Weidenmueller

We investigate the spectral fluctuation properties of constrained ensembles of random matrices (defined by the condition that a number N(Q) of matrix elements vanish identically; that condition is imposed in unitarily invariant form) in the limit of large matrix dimension. We show that as long as N(Q) is smaller than a critical value (at which the quadratic

Yen-Chen Lee, Hsiu-Hau Lin

We study the electronic correlation effects in armchair graphene nanoribbons that have been recently proposed to be the building blocks of spin qubits. The armchair edges give rise to peculiar quantum interferences and lead to quenched kinetic energy of the itinerant carriers at appropriate doping level. This is a beautiful one-dimensional analogy of the Lan

S. Yeo, J. E. Bunder, Hsiu-Hau Lin, Myung-Hwa Jung

The effects of magnetic doping on a EuB_6 single crystal were investigated based on magnetic and transport measurements. A modest 5% Sm substitution for Eu changes the magnetic and transport properties dramatically and gives rise to concurrent antiferromagnetic and metal-insulator transitions (MIT) from ferromagnetic MIT for EuB6. Magnetic doping simultaneou

David Damanik, Anton Gorodetski

We consider the spectrum of the Fibonacci Hamiltonian for small values of the coupling constant. It is known that this set is a Cantor set of zero Lebesgue measure. Here we study the limit, as the value of the coupling constant approaches zero, of its thickness and its Hausdorff dimension. We announce the following results and explain some key ideas that go

R. D. D. Costa, W. J. Maciel, A. V. Escudero

Recent work has produced a wealth of data concerning the chemical evolution of the galactic bulge, both for stars and nebulae. Present theoretical models generally adopt a limited range of such constraints, frequently using a single chemical element (usually iron), which is not enough to describe it unambiguously. In this work, we take into account constrain

Peter Collings

We investigate the representation of the symmetric group afforded by the action on its conjugacy class of fixed point free involutions, over an algebraically closed field of finite characteristic p. We discuss the general form of the set of involutions fixed by an arbitrary vertex of an irreducible component of the module afforded by the action, and show how

N. S. Hoang, A. G. Ramm

A review of the authors&#39;s results is given. Several methods are discussed for solving nonlinear equations $F(u)=f$, where $F$ is a monotone operator in a Hilbert space, and noisy data are given in place of the exact data. A discrepancy principle for solving the equation is formulated and justified. Various versions of the Dynamical Systems Method (DSM) f

Jordi Guardia

We give a closed formula for recovering a non-hyperelliptic genus three curve from its period matrix, and derive some identities between Jacobian Nullwerte in dimension three.

Melissa J. Spannuth, Jerome A. Neufeld, J. S. Wettlaufer, M. Grae Worster

We study the axisymmetric propagation of a viscous gravity current over a deep porous medium into which it also drains. A model for the propagation and drainage of the current is developed and solved numerically in the case of constant input from a point source. In this case, a steady state is possible in which drainage balances the input, and we present ana

M. Cristina Caputo, Alexis Vasseur

This paper is devoted to the study of the regularity of solutions to some systems of reaction--diffusion equations, with reaction terms having a subquadratic growth. We show the global boundedness and regularity of solutions, without smallness assumptions, in any dimension $N$. The proof is based on blow-up techniques. The natural entropy of the system plays

Ulrich W. Heinz

Relativistic hydrodynamics for ideal and viscous fluids is discussed as a tool to describe relativistic heavy-ion collisions and to extract transport properties of the quark-gluon plasma from experimentally measured hadron momentum spectra.

Christine Ruhland, Eric F. Bell, Boris Haeussler, Edward N. Taylor

We present first measurements of the evolution of the scatter of the cosmic average early-type galaxy color-magnitude relation (CMR) from z=1 to the present day, finding that it is consistent with models in which galaxies are constantly being added to the red sequence through truncation of star formation in blue cloud galaxies. We used a sample of over 700 r

I. Misgeld, M. Hilker, S. Mieske

We present a photometric study of the early-type dwarf galaxy population of the Centaurus cluster, aiming at investigating the galaxy luminosity function (LF) and galaxy scaling relations down to the regime of galaxies with M_V~-10 mag. On deep VLT/FORS1 V- and I-band images of the central part of the cluster, we identify cluster dwarf-galaxy candidates usin

N. S. Hoang, A. G. Ramm

A version of the Dynamical Systems Method (DSM) for solving ill-conditioned linear algebraic systems is studied in this paper. An {\it a priori} and {\it a posteriori} stopping rules are justified. An algorithm for computing the solution using a spectral decomposition of the left-hand side matrix is proposed. Numerical results show that when a spectral decom

Irina Kitiashvili, Laetitia Jacoutot, Alexander Kosovichev, Alan Wray

We have developed 3D, compressible, non-linear radiative MHD simulations to study the influence of the magnetic field of various strength and geometry on the turbulent convective cells and on the excitation mechanisms of the acoustic oscillations. The results reveal substantial changes of the granulation structure with increased magnetic field, and a frequen

Peter Koroteev, Maxim Libanov

We investigate five-dimensional braneworld setups with broken Lorentz invariance continuing the developments of our previous paper (arXiv:0712.1136), where a family of static self-tuning braneworld solutions was found. We show that several known braneworld models can be embedded into this family. Then we give a qualitative analysis of spectra of field fluctu

Andrew Pomerance, Edward Ott, Michelle Girvan, Wolfgang Losert

Boolean networks have been proposed as potentially useful models for genetic control. An important aspect of these networks is the stability of their dynamics in response to small perturbations. Previous approaches to stability have assumed uncorrelated random network structure. Real gene networks typically have nontrivial topology significantly different fr

Jean-Louis Colliot-Thélène, Boris Kunyavskiĭ, Vladimir L. Popov, Zinovy Reichstein

Let $k$ be a field of characteristic zero, let $G$ be a connected reductive algebraic group over $k$ and let $\mathfrak{g}$ be its Lie algebra. Let $k(G)$, respectively, $k(\mathfrak{g})$, be the field of $k$-rational functions on $G$, respectively, $\mathfrak{g}$. The conjugation action of $G$ on itself induces the adjoint action of $G$ on $\mathfrak{g}$. W

Mansoor Ur Rehman, Qaisar Shafi, Joshua R. Wickman

We study the effects of including one-loop radiative corrections in a non-supersymmetric hybrid inflationary model. These corrections can arise from Yukawa couplings between the inflaton and right-handed neutrinos, and induce a maximum in the potential which admits hilltop-type solutions in addition to the standard hybrid solutions. We obtain a red-tilted sp

Michael C. Cooper, Jeffrey A. Newman, Renbin Yan

Using data drawn from the Sloan Digital Sky Survey (SDSS) and the SDSS-II Supernova Survey, we study the local environments of confirmed type Ia supernovae (SNe Ia) in the nearby Universe. At 0.05 < z < 0.15, we find that SN Ia events in blue, star-forming galaxies occur preferentially in regions of lower galaxy density relative to galaxies of like stellar m

QUaD collaboration, R. B. Friedman, P. Ade, J. Bock

We present measurements of the cosmic microwave background (CMB) radiation temperature anisotropy in the multipole range 2000<ell<3000 from the QUaD telescope&#39;s second and third observing seasons. After masking the brightest point sources our results are consistent with the primary LCDM expectation alone. We estimate the contribution of residual (un-mask

Qimiao Si, Elihu Abrahams, Jianhui Dai, Jian-Xin Zhu

One of the central questions about the iron pnictides concerns the extent to which their electrons are strongly correlated. Here we address this issue through the phenomenology of the charge transport and dynamics, single-electron excitation spectrum, and magnetic ordering and dynamics. We outline the evidence that the parent compounds, while metallic, have

B. S. Mason, L. C. Weintraub, J. L. Sievers, J. R. Bond

The 100-m Robert C. Byrd Green Bank Telescope (GBT) and the Owens Valley Radio Observatory (OVRO) 40-m radio telescope have been used to conduct a survey of 3165 known extragalactic radio sources over 143 square degrees of the sky. Target sources were selected from the NRAO VLA Sky Survey in fields observed by the Cosmic Background Imager (CBI); most are ext