November 2008 arXiv papers — page 10

J. Dukelsky, J. Okolowicz, M. Ploszajczak

The formation of a higher-order singularity by the coalescence of two exceptional points is studied in the anti-hermitian limit of the complex-extended 3-level Richardson-Gaudin model.

W. J. de Wit, M. G. Hoare, T. Fujiyoshi, R. D. Oudmaijer

Massive young stellar objects (MYSO) are surrounded by massive dusty envelopes. Our aim is to establish their density structure on scales of ~1000 AU, i.e. a factor 10 increase in angular resolution compared to similar studies performed in the (sub)mm. We have obtained diffraction-limited (0.6") 24.5 micron images of 14 well-known massive star formation

A. F. Steklain, P. S. Letelier

A pseudo-Newtonian Hill problem based on a potential proposed by Artemova et al. [Astroph. J. 461 (1996) 565] is presented. This potential reproduces some of the general relativistic effects due to the spin angular momentum of the bodies, like the dragging of inertial frames. Poincare maps, Lyapunov exponents and fractal escape techniques are employed to stu

R. H. Colman, C. Ritter, A. S. Wills

The search for the resonating valence bond (RVB) state continues to underpin many areas of condensed matter research. The RVB is made from the dimerisation of spins on different sites into fluctuating singlets, and was proposed by Anderson to be the reference state from which the transition to BCS superconductivity occurs. Little is known about the state exp

R. Staubert, D. Klochkov, K. Postnov, N. Shakura

We present evidence for the existence of two ~35 day clocks in the Her X-1/HZ Her binary system. ~35 day modulations are observed 1) in the Turn-On cycles with two on- and two off-states, and 2) in the changing shape of the pulse profiles which re-appears regularly. The two ways of counting the 35 day cycles are generally in synchronization. This synchroniza

Thomas J. Maccarone, Robert P. Fender, Christian Knigge, A. K. Tzioumis

In light of the recent suggestion that the nearby eclipsing binary star system V Puppis has a dark companion on a long orbit, we present the results of radio and X-ray observations of it. We find an upper limit on its radio flux of about 300 $μ$Jy and a detection of it in the X-rays with a luminosity of about 3$\times10^{31}$ erg/sec, a value much lower than

C. Li, G. Lefkidis, W. Hübner

NiO is a good candidate for ultrafast magnetic switching because of its large spin density, antiferromagnetic order, and clearly separated intragap states. In order to detect and monitor the switching dynamics, we develop a systematic approach to study optical second harmonic generation (SHG) in NiO, both at the (001) surface and in the bulk. In our calculat

Marcella Longhetti, Paolo Saracco

The aim of the present paper is to quantify the dependence of the estimates of luminosities and stellar mass of early-type galaxies on the different models and model parameters which can be used to analyze the observational data. The paper is organized in two parts. The first one analyzes the dependence of the M/L ratios and of the k-corrections in different

Ali Sydney, Caterina Scoglio, Phillip Schumm, Robert Kooij

Just as a herd of animals relies on its robust social structure to survive in the wild, similarly robustness is a crucial characteristic for the survival of a complex network under attack. The capacity to measure robustness in complex networks defines the resolve of a network to maintain functionality in the advent of classical component failures and at the

Sachie Kimura, Aldo Bonasera

We discuss the alpha-muon sticking coefficient in the muon-catalysed d-t fusion in the framework of the Constrained Molecular Dynamics model. Especially the influence of muonic chaotic dynamics on the sticking coefficient is brought into focus. The chaotic motion of the muon affects not only the fusion cross section but also the muon-alpha sticking coefficie

T. Tatsumi, K. Sato

Taking into account the anomalous self-energy for quarks due to the dynamic screening effect for the transverse gluon propagator, we study the temperature dependence of the magnetic susceptibility in detail. It is shown that there does not exist the $T\ln T$ term in the susceptibility, different from the specific heat, but an anomalous $T^2\ln T$ term arises

Julie Gavard, J Silvio Gutkind

Increase in vascular permeability occurs under many physiological conditions and is central in diverse human pathologies. Thrombin is a pro-coagulant serine protease, which causes the local loss of endothelial barrier integrity thereby enabling the rapid extravasation of plasma proteins and the local formation of fibrin-containing clots. Available informatio

Dimitrios A. Gouliermis, Richard de Grijs, Yu Xin

We propose a new method for the characterization of stellar stratification in stellar systems. The method uses the mean-square radius (also called the Spitzer radius) of the system as a diagnostic tool. An estimate of the observable counterpart of this radius for stars of different magnitude ranges is used as the effective radius of each stellar species in a

J. Szczepkowski, R. Gartman, M. Witkowski, L. Tracewski

We describe the method allowing quantitative interpretation of absorptive images of mixtures of BEC and thermal atoms which reduces possible systematic errors associated with evaluation of the contribution of each fraction. By using known temperature dependence of the BEC fraction, the analysis allows precise calibration of the fitting results. The developed

Vo Tam Van, Hajime Matsui, Seiichi Mita

Generalized quasi-cyclic (GQC) codes form a wide and useful class of linear codes that includes thoroughly quasi-cyclic codes, finite geometry (FG) low density parity check (LDPC) codes, and Hermitian codes. Although it is known that the systematic encoding of GQC codes is equivalent to the division algorithm in the theory of Grobner basis of modules, there

A. A. Saharian

We investigate the Wightman function, the vacuum expectation values of the field squared and the energy-momentum tensor for a massive scalar field with general curvature coupling parameter subject to Robin boundary conditions on two codimension one parallel branes located on $(D+1)$-dimensional background spacetime $AdS_{D_{1}+1}\times Σ$ with a warped inter

Bike Xie, Mihaela van der Schaar, Richard D. Wesel

This paper proposes an analytical framework for peer-to-peer (P2P) networks and introduces schemes for building P2P networks to approach the minimum weighted average download time (WADT). In the considered P2P framework, the server, which has the information of all the download bandwidths and upload bandwidths of the peers, minimizes the weighted average dow

Arnaud Bodin, Pierre Dèbes, Salah Najib

We address some questions concerning indecomposable polynomials and their spectrum. How does the spectrum behave via reduction or specialization, or via a more general ring morphism? Are the indecomposability properties equivalent over a field and over its algebraic closure? How many polynomials are decomposable over a finite field?

Fuquan Fang, Yuguang Zhang, Zhenlei Zhang

The main result of this paper shows that, if $g(t)$ is a complete non-singular solution of the normalized Ricci flow on a noncompact 4-manifold $M$ of finite volume, then the Euler characteristic number $χ(M)\geq0$. Moreover, $χ(M)\neq 0$, there exist a sequence times $t_k\to\infty$, a double sequence of points $\{p_{k,l}\}_{l=1}^{N}$ and domains $\{U_{k,l}\

N. S. Witte

We derive the Christoffel-Geronimus-Uvarov transformations of a system of bi-orthogonal polynomials and associated functions on the unit circle, that is to say the modification of the system corresponding to a rational modification of the weight function. In the specialisation of the weight function to the regular semi-classical case with an arbitrary number

Ben Dundee, Stuart Raby, Akin Wingerter

In a recent paper, by working in the orbifold GUT limit of the Heterotic string, we showed how one could accommodate gauge coupling unification in the "mini-landscape" models of Lebedev et al. Furthermore, it was shown how one of the solutions was consistent with the decoupling of other exotics with F=0. In this short addendum, we show that this solu

Julie Gavard, J Silvio Gutkind

Endothelial barrier function requires the adhesive activity of VE-cadherin and claudin-5, which are key components of adherens and tight endothelial junctions, respectively. Emerging evidence suggests that VE-cadherin controls claudin-5 expression by preventing the nuclear accumulation of FoxO1 and -catenin, which repress the claudin-5 promoter. This indicat

Elizabete Rodrigues Ferreira, Philippe Boulanger, Michel Destrade

In the context of the finite elasticity theory, we consider a model for compressible solids called 'compressible neo-Hookean material'. We show how finite-amplitude inhomogeneous plane wave solutions and finite-amplitude unattenuated solutions can combine to form a finite-amplitude Love wave. We take a layer of finite thickness overlying a solid half

Ciprian Coman, Michel Destrade

The bifurcation of an incompressible neo-Hookean thick block with a ratio of thickness to length {eta}, subject to pure bending, is considered. The two incremental equilibrium equations corresponding to a nonlinear pre-buckling state of strain are reduced to a fourth-order linear eigenproblem that displays a multiple turning point. It is found that for 0 < {

T. Futamase, P. A. Hogan, Y. Itoh

We present the details of a model in general relativity of a small charged black hole moving in an external gravitational and electromagnetic field. The importance of our model lies in the fact that we can derive the equations of motion of the black hole from the Einstein-Maxwell vacuum field equations without encountering infinities. The key assumptions whi

O. Adriani

An important experiment for cosmic ray physics is going to be conducted with the colliding proton beams of the CERN LHC. The equivalent energy of the 14 TeV center of mass energy of the colliding proton beams in the LHC is 1017eV in the laboratory frame. Two small electromagnetic calorimeters have been installed at zero degree collision angle +/-140m from th

Timur V. Tscherbul, Gerrit C. Groenenboom, Roman V. Krems, Alex Dalgarno

We use accurate quantum mechanical calculations to analyze the effects of parallel electric and magnetic fields on collision dynamics of OH(2Pi) molecules. It is demonstrated that spin relaxation in 3He-OH collisions at temperatures below 0.01 K can be effectively suppressed by moderate electric fields of order 10 kV/cm. We show that electric fields can be u

Jingsong He, Xiaodong Li

By using gauge transformations, we manage to obtain new solutions of (2+1)-dimensional Kadomtsev-Petviashvili(KP), Kaup-Kuperschmidt(KK) and Sawada-Kotera(SK) equations from non-zero seeds. For each of the preceding equations, a Galilean type transformation between these solutions $u_2$ and the previously known solutions $u_2^{\prime}$ generated from zero se

Massimiliano Esposito, Michael Galperin

A simple scheme capable of treating transport in molecular junctions in the language of many-body states is presented. An ansatz in Liouville space similar to generalized Kadanoff-Baym approximation is introduced in order to reduce exact equation-of-motion for Hubbard operator to quantum master equation (QME)-like expression. A dressing with effective Liouvi

K. A. Ten, V. M. Aulchenko, L. A. Lukjanchikov, E. R. Pruuel

This paper describes the experimental studies of the formation of nano-diamonds during detonation of TNT/RDX 50/50 mixture with small-angle x-ray scattering (SAXS) method at a synchrotron radiation beam on VEPP-3 accelerator. A new experimental method with introduction of nano-diamonds into the explosive has been applied. Inclusion of the diamonds obtained a

Gaku Motoyama, Nobuyuki Yokoyama, Akihiko Sumiyama, Yasukage Oda

We carried out simultaneous measurements of electrical resistivity and thermal expansion of the heavy-fermion compound URu2Si2 under pressure using a single crystal. We observed a phase transition anomaly between hidden (HO) and antiferromagnetic (AFM) ordered states at TM in the temperature dependence of both measurements. For the electrical resistivity, th

D. Sheng, A. Perez Galvan, L. A. Orozco

We present lifetime measurements of the $5D_{3/2}$ and $5D_{5/2}$ states of rubidium using the time correlated single photon counting method. We perform the experiment in a magneto-optical trap of $^{87}$Rb atoms using a two-step excitation with the trap laser at 780 nm as the first step. We record the 761.9 nm fluorescence from the decay of the $5D_{3/2}$ s

T. Y. Xia, Y. Zhang

We present an analytical calculation of the spectra of CMB anisotropies and polarizations generated by relic gravitational waves (RGWs). As a substantial extension to the previous studies, three new ingredients are included in this work. Firstly, the analytic $C_l^{TT}$ and $C_l^{TE}$ are given; especially the latter can be useful to extract signal of RGWs f

Krishnam Raju Jampani, Anna Lubiw

In this paper we introduce the &#39;simultaneous membership problem&#39;, defined for any graph class C characterized in terms of representations, e.g. any class of intersection graphs. Two graphs G_1 and G_2, sharing some vertices X (and the corresponding induced edges), are said to be &#39;simultaneous members&#39; of graph class C, if there exist represen

Garcia de Andrade

Previously Chicone, Latushkin and Montgomery-Smith [\textbf{Comm. Math. Phys. \textbf{173},(1995)}] have investigated the spectrum of the dynamo operator for an ideally conducting fluid. More recently, Tang and Boozer [{\textbf{Phys. Plasmas (2000)}}], have investigated the anisotropies in magnetic field dynamo evolution, from finite-time, Lyapunov exponents

J. P. Lansberg

We discuss the various mechanisms potentially at work in hadroproduction of heavy quarkonia in the light of computations of higher-order QCD corrections both in the Colour-Singlet (CS) and Colour-Octet (CO) channels and the inclusion of the contribution arising from the s-channel cut in the CS channel. We also discuss new observables meant to better discrimi

W. J. Tango, J. Davis, A. P. Jacob, A. Mendez

The binary star delta Sco (HD143275) underwent remarkable brightening in the visible in 2000, and continues to be irregularly variable. The system was observed with the Sydney University Stellar Interferometer (SUSI) in 1999, 2000, 2001, 2006 and 2007. The 1999 observations were consistent with predictions based on the previously published orbital elements.

C. M. Varma

The conventional interpretation of the recent magneto-oscillation experiments in underdoped Cuprates, requires that there be a state of altered translational symmetry in the pseudogap state which is not supported by structural and Angle Resolved Photoemission Spectroscopy (ARPES) experiments. I show here that the observed oscillations may be reconciled with

Ken-ichi Sasaki, Yuji Shimomura, Yositake Takane, Katsunori Wakabayashi

We demonstrate that a tight-binding Hamiltonian with nearest- and next-nearest-neighbor hopping integrals can be decomposed into bulk and boundary parts in a general lattice system. The Hamiltonian decomposition reveals that next nearest-neighbor hopping causes sizable changes in the energy spectrum of surface states even if the correction to the energy spec

Gueorgui Todorov, Chenyang Xu

We prove the effectiveness of the log Iitaka fibration in Kodaira codimension two for varieties of dimension$\le 4$. In particular, we finish the proof of effective log Iitaka fibration in dimension two. Also, we show that for the log Iitaka fibration, if the fiber is of dimension two, the denominator of the moduli part is bounded.

Luis Alvarez-Gaume, Cesar Gomez, Agustin Sabio Vera, Alireza Tavanfar

We study the formation of marginally trapped surfaces in the head-on collision of two shock waves both in anti-de Sitter and Minkowski space-time in various dimensions as a function of the spread of the energy density in transverse space. For D=4 and D=5 it is shown that there exists a critical value of this spread above which no solution to the trapped surf

Tomasz Maszczyk

A resolution of the intersection of a finite number of subgroups of an abelian group by means of their sums is constructed, provided the lattice generated by these subgroups is distributive. This is used for detecting singularities of modules over Dedekind rings. A generalized Chinese remainder theorem is derived as a consequence of the above resolution. The

S. A. Baily, Y. Kohama, H. Hiramatsu, B. Maiorov

The temperature and angular dependence of the upper critical field (Hc2) is reported for cobalt-doped SrFe2As2 epitaxial films between Tc and 0.5 K in pulsed magnetic fields up to 50 T. For H parallel c, Hc2 is close to a linear function of temperature, while in the perpendicular direction there is significant downward curvature that results in an Hc2 ratio

B. Prasanna Venkatesh, M. Trupke, E. A. Hinds, D. H. J. O'Dell

Cold atoms in an optical lattice execute Bloch-Zener oscillations when they are accelerated. We have performed a theoretical investigation into the case when the optical lattice is the intra-cavity field of a driven Fabry-Perot resonator. When the atoms oscillate inside the resonator, we find that their back-action modulates the phase and intensity of the li

N. A. Leefer, A. Cingöz, D. Budker, S. J. Ferrell

Radio-frequency electric-dipole transitions between nearly degenerate, opposite parity levels of atomic dysprosium (Dy) were monitored over an eight-month period to search for a variation in the fine-structure constant, $\alpha$. The data provide a rate of fractional temporal variation of $\alpha$ of $(-2.4\pm2.3)\times10^{-15}$ yr$^{-1}$ or a value of $(-7.

Daniel J. Fenn, Mason A. Porter, Mark McDonald, Stacy Williams

We study the cluster dynamics of multichannel (multivariate) time series by representing their correlations as time-dependent networks and investigating the evolution of network communities. We employ a node-centric approach that allows us to track the effects of the community evolution on the functional roles of individual nodes without having to track enti

Anosh Joseph

We introduce particle phenomenology on the noncommutative spacetime called the Groenewold-Moyal plane. The length scale of spcetime noncommutativity is constrained from the CPT violation measurements in $K^{0}-\bar{K}^{0}$ system and $g-2$ difference of $μ^+ - μ^-$. The $K^{0}-\bar{K}^{0}$ system provides an upper bound on the length scale of spacetime nonco

Clifford Henry Taubes

This is the first of five papers that construct an isomorphism between the embedded contact homology and Seiberg-Witten Floer cohomology of a compact 3-manifold with a given contact 1-form. This paper describes what is involved in the construction.

Sami-Matias Niemi, Mauri Valtonen

Several authors have found a statistically significant excess of galaxies with higher redshifts relative to the group centre, so-called discordant redshifts, in particular in groups where the brightest galaxy, identified in apparent magnitudes, is a spiral. Our aim is to explain the observed redshift excess. We use a semi-analytical galaxy catalogue construc

Gilad Gour, Barry C. Sanders, Peter S. Turner

We show that appropriate superpositions of motional states are a reference frame resource that enables breaking of time -reversal superselection so that two parties lacking knowledge about the other&#39;s direction of time can still communicate. We identify the time-reversal reference frame resource states and determine the corresponding frameness monotone,

Hugo Gimbert, Florian Horn

We prove that optimal strategies exist in every perfect-information stochastic game with finitely many states and actions and a tail winning condition.

G. H. A. Roelofs, P. J. Groot, D. Steeghs, A. Rau

We describe a spectroscopic survey designed to uncover an estimated ~40 AM CVn stars hiding in the photometric database of the Sloan Digital Sky Survey (SDSS). We have constructed a relatively small sample of about 1500 candidates based on a colour selection, which should contain the majority of all AM CVn binaries while remaining small enough that spectrosc

Ramin A. Skibba, Steven P. Bamford, Robert C. Nichol, Chris J. Lintott

We analyze the environmental dependence of galaxy morphology and colour with two-point clustering statistics, using data from the Galaxy Zoo, the largest sample of visually classified morphologies yet compiled, extracted from the Sloan Digital Sky Survey. We present two-point correlation functions of spiral and early-type galaxies, and we quantify the correl

Stephan Ritter, Ferdinand Brennecke, Kristian Baumann, Tobias Donner

A Bose-Einstein condensate is dispersively coupled to a single mode of an ultra-high finesse optical cavity. The system is governed by strong interactions between the atomic motion and the light field even at the level of single quanta. While coherently pumping the cavity mode the condensate is subject to the cavity optical lattice potential whose depth depe

Robert T. Thompson, José P. S. Lemos

Calculation of the vacuum polarization, $<ϕ^2(x)>$, and expectation value of the stress tensor, $<T_{μν}(x)>$, has seen a recent resurgence, notably for black hole spacetimes. To date, most calculations of this type have been done only in four dimensions. Extending these calculations to $d$ dimensions includes $d$-dimensional renormalization. Typically, the

Kenneth J. Günter, Marc Cheneau, Tarik Yefsah, Steffen P. Rath

We propose a scheme to generate an Abelian gauge field in an atomic gas using two crossed laser beams. If the internal atomic state follows adiabatically the eigenstates of the atom-laser interaction, Berry&#39;s phase gives rise to a vector potential that can nucleate vortices in a Bose gas. The present scheme operates even for a large detuning with respect

Yang Kang, Abel Klein

We study the time evolution of a density matrix in a quantum mechanical system described by an ergodic magnetic Schrödinger operator with singular magnetic and electric potentials, the electric field being introduced adiabatically. We construct a unitary propagator that solves weakly the corresponding time-dependent Schrödinger equation, and solve a Liouvill

Ilias Cholis, Gregory Dobler, Douglas P. Finkbeiner, Lisa Goodenough

Multiple lines of evidence indicate an anomalous injection of high-energy e+- in the Galactic halo. The recent $e^+$ fraction spectrum from the Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics (PAMELA) shows a sharp rise up to 100 GeV. The Fermi Gamma-ray Space Telescope has found a significant hardening of the e+e- cosmic ray spectrum

Jose A. Gonzalez, Ulrich Sperhake, Bernd Bruegmann

We present the first numerical simulations of an initially non-spinning black-hole binary with mass ratio as large as 10:1 in full general relativity. The binary completes approximately 3 orbits prior to merger and radiates about 0.415% of the total energy and 12.48% of the initial angular momentum in the form of gravitational waves. The single black hole re

Teresia Mansson, Konstantinos Zoubos

We study the symmetries of the N=1 exactly marginal deformations of N=4 Super Yang-Mills theory. For generic values of the parameters, these deformations are known to break the SU(3) part of the R-symmetry group down to a discrete subgroup. However, a closer look from the perspective of quantum groups reveals that the Lagrangian is in fact invariant under a

A. V. Ershov

This paper has been withdrawn by the author.

Pavel Fileviez Perez, Hiren H. Patel, Michael. J. Ramsey-Musolf, Kai Wang

We investigate the predictions of a simple extension of the Standard Model where the Higgs sector is composed of one $SU(2)_L$ doublet and one real triplet. We discuss the general features of the model, including its vacuum structure, theoretical and phenomenological constraints, and expectations for Higgs collider studies. The model predicts the existence o

K. Cho, B. E. Smith, W. A. Coniglio, L. E. Winter

We report upper critical field measurements in the metal-free-all-organic superconductor $β&#39;&#39;$-(ET)$_{2}$SF$_{5}$CH$_{2}$CF$_{2}$SO$_{3}$ obtained from measuring the in-plane penetration depth using the tunnel diode oscillator technique. For magnetic field applied parallel to the conducting planes the low temperature upper critical fields are found t

Qing Chu

We prove the norm convergence of multiple ergodic averages along cubes for several commuting transformations, and derive corresponding combinatorial results. The method we use relies primarily on the &#34;magic extension&#34; established recently by B. ~Host.

Alikram N. Aliev, Dilek K. Ciftci

We show that the general solution of Chong, Cvetic, Lu and Pope for nonextremal rotating charged black holes in five-dimensional minimal gauged supergravity, or equivalently in the Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant and with the Chern-Simons coefficient $ ν=1 $, admits a simple description in a Kerr-Schild type framewo

Diego Catalano Ferraioli, Alexandre Vinogradov

Some new results on geometry of classical parabolic Monge-Ampère equations (PMA) are presented. PMAs are either \emph{integrable}, or \emph{nonintegrable} according to integrability of its characteristic distribution. All integrable PMAs are locally equivalent to the equation $u_{xx}=0$. We study nonintegrable PMAs by associating with each of them a 1-dimens

Ferenc Szöllősi

Constructions of Hadamard matrices from smaller blocks is a well-known technique in the theory of real Hadamard matrices: tensoring Hadamard matrices and the classical arrays of Williamson, Ito are all procedures involving smaller order building blocks. We apply a new block-construction for order 6 to obtain a previously unknown 2-dimensional family of compl

Wei Chen, A. V. Andreev, G. F. Bertsch

We study the conductance of an interconnect between two graphene leads formed by a single-atom carbon chain. Its dependence on the chemical potential and the number of atoms in the chain is qualitatively different from that in the case of normal metal leads. Electron transport proceeds via narrow resonant states in the wire. The latter arise due to strong re

Valentin Gutev, Narcisse Roland Loufouma Makala

We demonstrate that the classical Michael selection theorem for l.s.c. mappings with a collectionwise normal domain can be reduced only to compact-valued mappings modulo Dowker's extension theorem for such spaces. The idea used to achieve this reduction is also applied to get a simple direct proof of that selection theorem of Michael's. Some other possible a

C. C. Cheung, Stephen E. Healey, Hermine Landt, Gijs Verdoes Kleijn

We report optical spectroscopic observations of X-shaped radio sources with the Hobby-Eberly Telescope and Multiple-Mirror Telescope, focused on the sample of candidates from the FIRST survey presented in Paper I (Cheung 2007). A total of 27 redshifts were successfully obtained, 21 of which are new, including that of a newly identified candidate source of th

Daniel Baumann, Mark G. Jackson, Peter Adshead, Alexandre Amblard

We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high ener

C. J. M. Daumont, D. Mannix, Sriram Venkatesan, D. Rubi

TbMnO$_{3}$ films have been grown under compressive strain on (001)-oriented SrTiO$_{3}$ crystals. They have an orthorhombic structure and display the (001) orientation. With increasing thickness, the structure evolves from a more symmetric (tetragonal) to a less symmetric (bulk-like orthorhombic) structure, while keeping constant the in-plane compression th

Alan Cooney, Simon DeDeo, Dimitrios Psaltis

Major observational efforts in the coming decade are designed to probe the equation of state of dark energy. Measuring a deviation of the equation-of-state parameter w from -1 would indicate a dark energy that cannot be represented solely by a cosmological constant. While it is commonly assumed that any implied modification to the LambdaCDM model amounts to

S. R. Saha, N. P. Butch, K. Kirshenbaum, J. Paglione

Single crystals of SrFe2As2 grown using a self-flux solution method were characterized via x-ray, transport and magnetization studies, revealing a superconducting phase below T_c = 21 K characterized by a full electrical resistivity transition and partial diamagnetic screening. The reversible destruction and reinstatement of this phase by heat treatment and

J. A. Aguilar-Saavedra

We simplify the general form of the fermion-fermion-gauge boson interactions generated by dimension-six gauge-invariant effective operators by using the equations of motion to remove redundant operators. It is found that the most general vertex for off-shell fermions fi, fj and an off-shell boson V=W,Z,gamma,g only involves gamma^mu and sigma^{mu nu} q_nu te

Anders Johansen, Andrew Youdin, Hubert Klahr

We study the behavior of magnetorotational turbulence in shearing box simulations with a radial and azimuthal extent up to ten scale heights. Maxwell and Reynolds stresses are found to increase by more than a factor two when increasing the box size beyond two scale heights in the radial direction. Further increase of the box size has little or no effect on t

David Seery, Martin S. Sloth, Filippo Vernizzi

We compute the connected four-point correlation function of the primordial curvature perturbation generated during inflation with standard kinetic terms, where the correlation is established via exchange of a graviton between two pairs of scalar fluctuations. Any such correlation yields a contribution to the scalar trispectrum of the order of the tensor to s

Antonio Alfonso-Faus

It is shown that the usual choice of units obtained by taking G = c = Planck constant = 1, giving the Planck units of mass, length and time, introduces an artificial contradiction between cosmology and particle physics: the lambda problem that we associate with Planck constant. We note that the choice of Planck constant = 1 does not correspond to the scale o

G. Romero, J. J. Garcia-Ripoll, E. Solano

Quantum optical photodetection has occupied a central role in understanding radiation-matter interactions. It has also contributed to the development of atomic physics and quantum optics, including applications to metrology, spectroscopy, and quantum information processing. The quantum microwave regime, originally explored using cavities and atoms, is seeing

Nathan Smith, Mohan Ganeshalingam, Ryan Chornock, Alexei V. Filippenko

We present visual-wavelength photometry and spectroscopy of supernova SN2008S. Based on the low peak luminosity for a SN of M_R = -13.9 mag, photometric and spectral evolution unlike that of low-luminosity SNe, a late-time decline rate slower than 56Co decay, and slow outflow speeds of 600-1000 km/s, we conclude that SN2008S is not a true core-collapse SN an

Gerhart Seidl

We present a supersymmetric SU(5) GUT model with a discrete non-Abelian flavor symmetry that is broken by Wilson lines. The model is formulated in 4+3 dimensions compactified on a manifold S^3/Z_n. Symmetry breaking by Wilson lines is topological and allows to realize the necessary flavor symmetry breaking without a vacuum alignment mechanism. The model pred

Cao Wang, Shuai Jiang, Qian Tao, Zhi Ren

We report the realization of superconductivity by an isovalent doping with phosphorus in LaFeAsO. X-ray diffraction shows that, with the partial substitution of P for As, the Fe$_2$As$_2$ layers are squeezed while the La$_2$O$_2$ layers are stretched along the c-axis. Electrical resistance and magnetization measurements show emergence of bulk superconductivi

Antonio Enea Romano

We show how inhomogeneous cosmological models can naturally explain the large angle correlation we observe in the CMB (cosmological microwave background) radiation without invoking any inflationary stage, but simply considering the effects of inhomogeneities on the propagation of photons from the last scattering surface.

Lorenzo Iorio

We investigate qualitatively and quantitatively the impact of the general relativistic gravito-electromagnetic forces on hyperbolic orbits around a massive spinning body. The gravito-magnetic field, which is the cause of the well known Lense-Thirring precessions of elliptic orbits, is generated by the spin S of the central body. It deflects and displaces the

I. Boisse, C. Moutou, A. Vidal-Madjar, F. Bouchy

Extra-solar planet search programs require high-precision velocity measurements. They need to study how to disentangle radial-velocity variations due to Doppler motion from the noise induced by stellar activity. We monitored the active K2V star HD 189733 and its transiting planetary companion that has a 2.2-day orbital period. We used the high-resolution spe

Weiqun Zhang, Andrew MacFadyen, Peng Wang

Magnetic field strengths inferred for relativistic outflows including gamma-ray bursts (GRB) and active galactic nuclei (AGN) are larger than naively expected by orders of magnitude. We present three-dimensional relativistic magnetohydrodynamics (MHD) simulations demonstrating amplification and saturation of magnetic field by a macroscopic turbulent dynamo t

Gianfranco Bertone, Marco Cirelli, Alessandro Strumia, Marco Taoso

PAMELA and ATIC recently reported an excess in e+e- cosmic rays. We show that if it is due to Dark Matter annihilations, the associated gamma-ray flux and the synchrotron emission produced by e+e- in the galactic magnetic field violate HESS and radio observations of the galactic center and HESS observations of dwarf Spheroidals, unless the DM density profile

J. Dunkley, A. Amblard, C. Baccigalupi, M. Betoule

In this report we discuss the impact of polarized foregrounds on a future CMBPol satellite mission. We review our current knowledge of Galactic polarized emission at microwave frequencies, including synchrotron and thermal dust emission. We use existing data and our understanding of the physical behavior of the sources of foreground emission to generate sky

Miguel Couceiro, Jean-Luc Marichal

Two emergent properties in aggregation theory are investigated, namely horizontal maxitivity and comonotonic maxitivity (as well as their dual counterparts) which are commonly defined by means of certain functional equations. We completely describe the function classes axiomatized by each of these properties, up to weak versions of monotonicity in the cases

J. Schneider, A. Boccaletti, D. Mawet, P. Baudoz

The Super-Earth Explorer is an Off-Axis Space Telescope (SEE-COAST) designed for high contrast imaging. Its scientific objective is to make the physico-chemical characterization of exoplanets possibly down to 2 Earth radii >. For that purpose it will analyze the spectral and polarimetric properties of the parent starlight reflected by the planets, in the wav

H. E. S. S. Collaboration, :, F. Aharonian

The very large collection area of ground-based gamma-ray telescopes gives them a substantial advantage over balloon/satellite based instruments in the detection of very-high-energy (>600 GeV) cosmic-ray electrons. Here we present the electron spectrum derived from data taken with the H.E.S.S. system of imaging atmospheric Cherenkov telescopes. In this measur

G. Dirr, U. Helmke, I. Kurniawan, T. Schulte-Herbrueggen

In view of controlling finite dimensional open quantum systems, we provide a unified Lie-semigroup framework describing the structure of completely positive trace-preserving maps. It allows (i) to identify the Kossakowski-Lindblad generators as the Lie wedge of a subsemigroup, (ii) to link properties of Lie semigroups such as divisibility with Markov propert

Fred Cooper, John F. Dawson, Bogdan Mihaila

The transverse distribution of gluon and quark-antiquark pairs produced from a strong constant chromo-electric field depends on two gauge invariant quantities, $C_1=E^aE^a$ and $C_2=[d_{abc}E^aE^bE^c]^2$, as shown earlier in [G.C. Nayak and P. van Nieuwenhuizen, Phys. Rev. D 71, 125001 (2005)] for gluons and in [G.C. Nayak, Phys. Rev. D 72, 125010 (2005)] fo

H. Bartko, F. Martins, T. K. Fritz, R. Genzel

The central parsec around the super-massive black hole in the Galactic Center hosts more than 100 young and massive stars. Outside the central cusp (R~1&#34;) the majority of these O and Wolf-Rayet (WR) stars reside in a main clockwise system, plus a second, less prominent disk or streamer system at large angles with respect to the main system. Here we prese

Anamitra Mukherjee, Pinaki Majumdar

We study the effect of A site disorder on magnetic field induced melting of charge order (CO) in half doped manganites using a Monte-Carlo technique. Strong A-site disorder destroys CO even without an applied field. At moderate disorder, the zero field CO state survives but has several intriguing features in its field response. Our spatially resolved results

Giovanni Catino, Cheikh Birahim Ndiaye

We prove that some Riemannian manifolds with boundary under an explicit integral pinching are spherical space forms. Precisely, we show that 3-dimensional Riemannian manifolds with totally geodesic boundary, positive scalar curvature and an explicit integral pinching between the $L^2$-norm of their scalar curvature and the $L^2$-norm of their Ricci tensor ar

Ching-Wa Yip, Andrew Connolly, Daniel Vanden Berk, Ryan Scranton

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type 2 AGN to be composed mainly of stellar light and non-variable on the time-scales of months to years. In this work we pro

R. Mélin, F. S. Bergeret, A. Levy Yeyati

We implement self-consistent microscopic calculations in order to describe out-of-equilibrium non-local transport in normal metal-superconductor-normal metal hybrid structures in the presence of a magnetic field and for arbitrary interface transparencies. A four terminal setup simulating usual experimental situations is described by means of a tight-binding

J. Fynbo, D. Malesani

Long-duration gamma-ray bursts are the manifestations of massive stellar death. Due to the immense energy release they are detectable from most of the observable universe. In this way they allow us to study the deaths of single (or binary) massive stars possibly throughout the full timespan massive stars have existed in the Universe. GRBs provide a means to

Simon R. Blackburn, Tuvi Etzion, Keith M. Martin, Maura B. Paterson

A distinct difference configuration is a set of points in $\mathbb{Z}^2$ with the property that the vectors (\emph{difference vectors}) connecting any two of the points are all distinct. Many specific examples of these configurations have been previously studied: the class of distinct difference configurations includes both Costas arrays and sonar sequences,