April 2009 arXiv papers — page 8

Panagiota K. Karahaliou, Alexandros G. Vanakaras, Demetri J. Photinos

The possible symmetries of the biaxial nematic phase are examined against the implications of the presently available experimental results. Contrary to the widespread notion that biaxial nematics have orthorhombic symmetry, our study shows that a monoclinic ($C_{2h}$) symmetry is more likely to be the case for the recently observed phase biaxiality in thermo

Joseph Marsano, Natalia Saulina, Sakura Schafer-Nameki

We construct a family of elliptically fibered Calabi-Yau four-folds Y_4 for F-theory compactifications that realize SU(5) GUTs in the low-energy limit. The three-fold base X_3 of these fibrations is almost Fano and satisfies the topological criteria required to ensure that the U(1)_Y gauge boson remains massless, while allowing a decoupling of GUT and Planck

Juergen Herzog, Takayuki Hibi, Hidefumi Ohsugi

We give criteria for graded ideals to have the property that all their powers are componentwise linear. Typical examples to which our criteria can be applied include the vertex cover ideals of certain finite graphs.

Alain Gellé, Julien Varignon, Marie-Bernadette Lepetit

We propose a new ab initio method designed for the accurate calculation of effective exchange integrals between atoms with numerous open-shells. This method applies to ferromagnetic as well as antiferromagnetic exchange, direct or ligand-mediated exchange. Test calculations on high spin transition metal oxides such as KNiF3, Ba2CoS3 or YMnO3 exhibit a very g

Yves Cornulier

We study the Cantor-Bendixson rank of metabelian and virtually metabelian groups in the space of marked groups, and in particular, we exhibit a sequence (G_n) of 2-generated, finitely presented, virtually metabelian groups of Cantor-Bendixson rank omega^n.

A. Mironov, A. Morozov, S. Natanzon

We define cut-and-join operator in Hurwitz theory for merging of two branching points of arbitrary type. These operators have two alternative descriptions:(i) they have the GL characters as eigenfunctions and the symmetric-group characters as eigenvalues; (ii) they can be represented as differential operators of the $W$-type (in particular, acting on the tim

C. L. Reichardt, O. Zahn, P. A. R. Ade, K. Basu

We present measurements of the angular power spectrum of millimeter wave anisotropies with the APEX-SZ instrument. APEX-SZ has mapped 0.8 square degrees of sky at a frequency of 150 GHz with an angular resolution of 1&#39;. These new measurements significantly improve the constraints on anisotropy power at 150 GHz over the range of angular multipoles 3000 <

Guido Berlin, Gilles Brassard, Felix Bussieres, Nicolas Godbout

Coin flipping is a cryptographic primitive in which two distrustful parties wish to generate a random bit in order to choose between two alternatives. This task is impossible to realize when it relies solely on the asynchronous exchange of classical bits: one dishonest player has complete control over the final outcome. It is only when coin flipping is suppl

Alexander A. Gaifullin

In this paper we construct and study a new 15-vertex triangulation $X$ of the complex projective plane $\CP^2$. The automorphism group of $X$ is isomorphic to $S_4\times S_3$. We prove that the triangulation $X$ is the minimal by the number of vertices triangulation of $\CP^2$ admitting a chess colouring of four-dimensional simplices. We provide explicit par

Dorje C. Brody

Using a sheaf-theoretic extension of conventional principal bundle theory, the Dirac monopole is formulated as a spherically symmetric model free of singularities outside the origin such that the charge may assume arbitrary real values. For integral charges, the construction effectively coincides with the usual model. Spin structures and Dirac operators are

Igor B. Mekhov, Helmut Ritsch

Cavity enhanced light scattering off an ultracold gas in an optical lattice constitutes a quantum measurement with a controllable form of the measurement back-action. Time-resolved counting of scattered photons alters the state of the atoms without particle loss implementing a quantum nondemolition (QND) measurement. The conditional dynamics is given by the

Peter Adshead, Richard Easther, Eugene A. Lim

We describe an efficient scheme for evaluating higher order contributions to primordial cosmological perturbations using the &#34;in-in&#34; formalism, which is the basis of modern calculations of non-Gaussian and higher order contributions to the primordial spectrum. We show that diagrams with two or more vertices require careful handling. We present an imp

Michał Krych, Zbigniew Idziaszek

We consider controlled collisions between two ultracold atoms guided by external harmonic potentials. We derive analytical solutions of the Schroedinger equation for this system, and investigate the properties of eigenergies and eigenstates for different trap geometries as a function of a trap separation and of the scattering length. When varying the trap se

Christian Liedtke, Stavros Argyrios Papadakis

We describe elementary transformations between minimal models of rational surfaces in terms of unprojections. These do not fit into the framework of Kustin-Miller unprojections as introduced by Papadakis and Reid, since we have to leave the world of projectively Gorenstein varieties. Also, our unprojections do not depend on the choice of the unprojection loc

Pierre-Ugo Tournoux, Emmanuel Lochin, Jerome Lacan, Amine Bouabdallah

This paper introduces a robust point-to-point transmission scheme: Tetrys, that relies on a novel on-the-fly erasure coding concept which reduces the delay for recovering lost data at the receiver side. In current erasure coding schemes, the packets that are not rebuilt at the receiver side are either lost or delayed by at least one RTT before transmission t

M. Abdel-Aty, M. Everitt

We explore the role played by the intrinsic decoherence in superconducting charge qubits in the presence of a microwave field applied as a magnetic flux. We study how the delayed creation of entanglement, which is opposite to the sudden death of entanglement, can be induced. We compute the time evolution of the population inversion, total correlation and ent

Shahar Dobzinski, Shaddin Dughmi

In many settings the power of truthful mechanisms is severely bounded. In this paper we use randomization to overcome this problem. In particular, we construct an FPTAS for multi-unit auctions that is truthful in expectation, whereas there is evidence that no polynomial-time truthful deterministic mechanism provides an approximation ratio better than 2. We a

Pham Hoang Hiep

We study Hölder continuity of solutions to the Monge-Ampère equations on compact Kähler manifolds. In [DNS] the authors have shown that the measure $ω_u^n$ is moderate if $u$ is Hölder continuous. We prove a theorem which is a partial converse to this result.

Eimear O&#39;Callaghan, Ruth Gregory, Alkistis Pourtsidou

We consider the asymmetric branes model of modified gravity, which can produce late time acceleration of the universe and compare the cosmology of this model to the standard $Λ$CDM model and to the DGP braneworld model. We show how the asymmetric cosmology at relevant physical scales can be regarded as a one-parameter extension of the DGP model, and investig

Rong-Gen Cai, Yan Liu, Ya-Wen Sun

We consider z=4 Horava-Lifshitz gravity in both 3+1 and 4+1 dimensions. We find black hole solutions in the IR region for a kind of z=4 Horava-Lifshitz gravity which is inherited from the new massive gravity in three dimensions and an analog of the new massive gravity in four dimensions through the quantum inheritance principle. We analyze thermodynamic prop

Thomas Mueller, Frank Grave

The Catalogue of Spacetimes is a collection of four-dimensional Lorentzian spacetimes in the context of the General Theory of Relativity (GR). The aim of the catalogue is to give a quick reference for students who need some basic facts of the most well-known spacetimes in GR.

Hongbo Cheng

The Casimir effect of a piston for massless scalar fields which satisfy Dirichlet boundary conditions in the context of five-dimensional Randall-Sundrum models is studied. In these scenarios we derive and calculate the expression for the Casimir force on the piston. We also discuss the Casimir force in the limit that one outer plate is moved to the remote pl

R. Ramirez, N. Sadovskaia

We construct a polynomial planar vector field of degree two with one invariant algebraic curves of large degree. We exhibit an explicit quadratic vector fields which invariant curves of degree nine, twelve, fifteen and eighteen degree.

Xian Gao

We investigate primordial perturbations and non-gaussianities in the Ho\v{r}ava-Lifshitz theory of gravitation. In the UV limit, the scalar perturbation in the Ho\v{r}ava theory is naturally scale-invariant, ignoring the details of the expansion of the Universe. One may thus relax the exponential inflation and the slow-roll conditions for the inflaton field.

Brian A. Munson, Ismar Volic

Manifold calculus of functors, due to M. Weiss, studies contravariant functors from the poset of open subsets of a smooth manifold to topological spaces. We introduce &#34;multivariable&#34; manifold calculus of functors which is a generalization of this theory to functors whose domain is a product of categories of open sets. We construct multivariable Taylo

G. Kaniadakis

In ordinary statistical mechanics the Boltzmann-Shannon entropy is related to the Maxwell-Bolzmann distribution $p_i$ by means of a twofold link. The first link is differential and is offered by the Jaynes Maximum Entropy Principle. The second link is algebraic and imposes that both the entropy and the distribution must be expressed in terms of the same func

Romain Dujardin

In this paper we give the first examples of positive closed currents in $\mathbb{C}^2$ with continuous potentials, vanishing self-intersection, and which are not laminar. More precisely, they are supported on sets &#34;without analytic structure&#34;. The result is mostly interesting when the potential has regularity close to $C^2$, because laminarity is exp

Babiker Hassanain, John March-Russell, J. G. Rosa

In string realizations of the Randall-Sundrum scenario, the higher-spin Regge excitations of Standard Model states localized near the IR brane are warped down to close to the TeV scale. We argue that, as a consequence of the localization properties of Randall-Sundrum models of flavour, the lightest such resonance is the spin-3/2 excitation of the right-hande

Nicolas Bonnel, Pierre-François Marteau, Gildas G. Ménier

We present and study in this paper a simple algorithm that produces so called growing Parallel Random Apollonian Networks (P-RAN) in any dimension d. Analytical derivations show that these networks still exhibit small-word and scale-free characteristics. To characterize further the structure of P-RAN, we introduce new parameters that we refer to as the paral

Romain Abraham, Jean-François Delmas

We present a construction of a Lévy continuum random tree (CRT) associated with a super-critical continuous state branching process using the so-called exploration process and a Girsanov&#39;s theorem. We also extend the pruning procedure to this super-critical case. Let $ψ$ be a critical branching mechanism. We set $ψ_θ(\cdot)=ψ(\cdot+θ)-ψ(θ)$. Let $Θ=(θ_\i

Andras Vukics

C++QED is a framework for simulating open quantum dynamics in general. Historically, it has in the first place been developed for problems in moving-particle cavity QED, but since then has been applied in other fields as well. It is known to be able to simulate full Master equation up to several thousand, and quantum trajectories up to several hundred thousa

Bruno Goncalves, Guilherme de Berredo-Peixoto, Ilya L. Shapiro

The well-known formula $det(A\cdot B)=\det A \cdot \det B$ can be easily proved for finite dimensional matrices but it may be incorrect for the functional determinants of differential operators, including the ones which are relevant for Quantum Field Theory applications. Considerable work has been done to prove that this equality can be violated, but in all

Jakob Bork, Jens Onsgaard, Lars Diekhöner

We have studied the growth of Ag on bilayer high Co nanoislands on Cu(111) using Scanning Tunneling Microscopy. Noble metal capping of magnetic nanostructures is known to influence the magnetism and knowledge of the growth is therefore important. We find that Ag preferentially nucleates on the Co nanoislands initially leaving the free Cu sites clean. Further

Su-Peng Kou

In this paper, the degenerate ground states of Z2 topological order on a plane with holes (the so-called surface codes) are used as the protected code subspace to build a topological quantum computer by tuning their quantum tunneling effect. Using a designer Hamiltonian - the Kitaev toric-code model as an example, we study quantum tunneling effects of the su

Armin Rainer

We prove that the roots of a definable $C^\infty$ curve of monic hyperbolic polynomials admit a definable $C^\infty$ parameterization, where `definable&#39; refers to any fixed o-minimal structure on $(\mathbb R,+,\cdot)$. Moreover, we provide sufficient conditions, in terms of the differentiability of the coefficients and the order of contact of the roots,

Samir Garzon, Richard A. Webb, Mark Covington, Shehzaad Kaka

In large magnetoresistance devices spin torque-induced changes in resistance can produce GHz current and voltage oscillations which can affect magnetization reversal. In addition, capacitive shunting in large resistance devices can further reduce the current, adversely affecting spin torque switching. Here, we simultaneously solve the Landau-Lifshitz-Gilbert

D. A. García-Hernández, F. Bunzel, D. Engels, J. V. Perea-Calderón

We present AKARI/IRC and Spitzer/IRS observations of a selected sample of galactic IRAS sources considered to be heavily obscured AGB/post-AGB stars based on their characteristic IRAS colours. All of them are completely invisible in the optical range but extremely bright in the infrared. Based on AKARI and Spitzer spectroscopy and using DUSTY we are able to

Piotr Garbaczewski, Vladimir Stephanovich

We analyze confining mechanisms for Lévy flights. When they evolve in suitable external potentials their variance may exist and show signatures of a superdiffusive transport. Two classes of stochastic jump - type processes are considered: those driven by Langevin equation with Lévy noise and those, named by us topological Lévy processes (occurring in systems

Jeong-woo Cho, Yuming Jiang

This paper discovers fundamental principles of the backoff process that governs the performance of IEEE 802.11. A simplistic principle founded upon regular variation theory is that the backoff time has a truncated Pareto-type tail distribution with an exponent of $(\log γ)/\log m$ ($m$ is the multiplicative factor and $γ$ is the collision probability). This

Adam Rudzinski, Mariusz Puchalski, Krzysztof Pachucki

The magnetic shielding $σ$ of $^3$He is studied. The complete relativistic corrections of order $O(α^2)$, leading QED corrections of order $O(α^3 \lnα)$, and finite nuclear mass effects of order $O(m/m_{\rm N})$ are calculated with high numerical precision. The resulting theoretical predictions for $σ= 59.967~43(10)\cdot 10^{-6}$ are the most accurate to dat

Philippe Corboz, Glen Evenbly, Frank Verstraete, Guifre Vidal

We propose and test an algorithm to simulate a lattice system of interacting fermions in two spatial dimensions. The approach is an extension of the entanglement renormalization technique [Phys. Rev. Lett. 99, 220405 (2007)] and the related multi-scale entanglement renormalization ansatz. Benchmark calculations for free and interacting fermions on a lattice

Chun-peng Chang, Hsiang-nan Li

We discuss the applicability of the $k_T$ factorization theorem to low-$p_T$ hadron production in hadron-hadron collision in a simple toy model, which involves only scalar particles and gluons. It has been shown that the $k_T$ factorization for high-$p_T$ hadron hadroproduction is broken by soft gluons in the Glauber region, which are exchanged among a trans

M. Zeppenfeld, M. Motsch, P. W. H. Pinkse, G. Rempe

We present an opto-electrical cooling scheme for polar molecules based on a Sisyphus-type cooling cycle in suitably tailored electric trapping fields. Dissipation is provided by spontaneous vibrational decay in a closed level scheme found in symmetric-top rotors comprising six low-field-seeking rovibrational states. A generic trap design is presented. Suitab

Joana Cirici

We study the varieties of invariant totally geodesic submanifolds of isometries of the spherical, Euclidean and hyperbolic spaces in each finite dimension. We show that the dimensions of the connected components of these varieties determine the orbit type (or the z-class) of the isometry. For this purpose, we introduce the Segre symbol of an isometry, a disc

F. Bunzel, D. A. García-Hernández, D. Engels, J. V. Perea-Calderón

We present AKARI/IRC observations of a sample of six extremely red IRAS sources, of which three are variable OH/IR stars and the rest are early post-AGB stars. The OH/IR stars show a red continuum with the expected strong 10 micron silicate absorption feature, while the post-AGB stars show an even redder continuum accompanied with a comparably weak silicate

Zakhar Kabluchko

Let $\{X_{i,j}:(i,j)\in\mathbb N^2\}$ be a two-dimensional array of independent copies of a random variable $X$, and let $\{N_n\}_{n\in\mathbb N}$ be a sequence of natural numbers such that $\lim_{n\to\infty}e^{-cn}N_n=1$ for some $c>0$. Our main object of interest is the sum of independent random products $$Z_n=\sum_{i=1}^{N_n} \prod_{j=1}^{n}e^{X_{i,j}}.$$

Alexander Weiss

In a recent paper, Alfonsi, Fruth and Schied (AFS) propose a simple order book based model for the impact of large orders on stock prices. They use this model to derive optimal strategies for the execution of large orders. We apply these strategies to an agent-based stochastic order book model that was recently proposed by Bovier, Černý and Hryniv, but alrea

S. S. Manna

We considered a stochastic version of the Bak-Sneppen model (SBSM) of ecological evolution where the the number $M$ of sites mutated in a mutation event is restricted to only two. Here the mutation zone consists of only one site and this site is randomly selected from the neighboring sites at every mutation event in an annealed fashion. The critical behavior

M. B. Sheftel, D. Yazici

In the recent paper by one of the authors (MBS) and A. A. Malykh on the classification of second-order PDEs with four independent variables that possess partner symmetries (J. Phys. A: Math. Theor. Vol. 42 (2009) 395202 (20pp)), mixed heavenly equation and Husain equation appear as closely related canonical equations admitting partner symmetries. Here for th

Ugo Dal Lago, Simone Martini

We prove that orthogonal constructor term rewrite systems and lambda-calculus with weak (i.e., no reduction is allowed under the scope of a lambda-abstraction) call-by-value reduction can simulate each other with a linear overhead. In particular, weak call-by-value beta-reduction can be simulated by an orthogonal constructor term rewrite system in the same n

Guido Berlin, Gilles Brassard, Felix Bussieres, Nicolas Godbout

Coin flipping is a cryptographic primitive in which two spatially separated players, who in principle do not trust each other, wish to establish a common random bit. If we limit ourselves to classical communication, this task requires either assumptions on the computational power of the players or it requires them to send messages to each other with sufficie

Mikolaj Bojanczyk

We consider a temporal logic EF+F^-1 for unranked, unordered finite trees. The logic has two operators: EFϕ, which says &#34;in some proper descendant ϕholds&#34;, and F^-1ϕ, which says &#34;in some proper ancestor ϕholds&#34;. We present an algorithm for deciding if a regular language of unranked finite trees can be expressed in EF+F^-1. The algorithm uses

Yun-Song Piao

Recently, Hořava has proposed a renormalizable theory of gravity with critical exponent z=3 in the UV. This proposal might imply the scale invariant primordial perturbation can be generated in any expansion of early universe with a\sim t^n and n>1/3, which, in this note, will be validated by solving the motion equation of perturbation mode on super sound hor

G. E. Volovik

Recently Horava proposed a model for gravity which is described by the Einstein action in the infrared, but lacks the Lorentz invariance in the high-energy region where it experiences the anisotropic scaling. We test this proposal using two condensed matter examples of emergent gravity: acoustic gravity and gravity emerging in the fermionic systems with Ferm

J. X. Lu, Shan-Shan Xu

We extend the amplitude calculations of \cite{Lu:2009yx} to exhaust the remaining cases for which one set of D$_p$ branes carrying a flux (electric or magnetic) is placed parallel at separation to the other set carrying also a flux but with the two fluxes sharing at most one common field-strength index. We then find that the basic structure of amplitudes rem

M. Kugler, T. Andlauer, T. Korn, A. Wagner

We have investigated spin and carrier dynamics of resident holes in high-mobility two-dimensional hole systems in GaAs/Al$_{0.3}$Ga$_{0.7}$As single quantum wells at temperatures down to 400 mK. Time-resolved Faraday and Kerr rotation, as well as time-resolved photoluminescence spectroscopy are utilized in our study. We observe long-lived hole spin dynamics

A. M. Kamenetskii

Combinatorial formulas expressing cyclic rook polynomials and cyclic permanents of rectangular matrices in terms of expansions along rows are presented

Isabella Ianni, David Ruiz

In this paper the following version of the Schrodinger-Poisson-Slater problem is studied: $$ - Δu + (u^2 \star \frac{1}{|4πx|}) u=μ|u|^{p-1}u, $$ where $u: \R^3 \to \R$ and $μ>0$. The case $p <2$ being already studied, we consider here $p \geq 2$. For $p>2$ we study both the existence of ground and bound states. It turns out that $p=2$ is critical in a certa

Fabio Ferrari Ruffino

We discuss the relations between the Atiyah-Hirzebruch spectral sequence and the Gysin map for a multiplicative cohomology theory, on spaces having the homotopy type of a finite CW-complex. In particular, let us fix such a multiplicative cohomology theory h* and let us consider a smooth manifold X of dimension n and a compact submanifold Y of dimension p, sa

M. Bartolozzi, C. Mellen

In the present work we address the problem of evaluating the historical performance of a trading strategy or a certain portfolio of assets. Common indicators such as the Sharpe ratio and the risk adjusted return have significant drawbacks. In particular, they are global indices, that is they do not preserve any &#39;local&#39; information about the performan

Laura Portinari, Paolo Salucci

The colour and metallicity gradients observed in spiral galaxies suggest that the mass-to-light ratio (M*/L) of the stellar disc is a function of radius. This is indeed predicted by chemo-photometric models of galactic discs. We investigate the distribution of luminous and dark matter in spiral galaxies, taking into account the radial dependence of the stell

Denis Potapov, Fedor Sukochev

This paper resolves a number of conjectures in the perturbation theory of linear operators. Namely, we prove that every Lipschitz function is operator Lipschitz in the Schatten-von Neumann ideals $S^α$, $1 < α< \infty$. The negative result for $S^α$, $α= 1, \infty$ was earlier established by Yu. Farforovskaya in 1972.

Mustafa Sarisaman

We study the pseudoduality transformation on the symmetric space sigma models. We switch the Lie group valued pseudoduality equations to Lie algebra valued ones, which leads to an infinite number of pseudoduality equations. We obtain an infinite number of conserved currents on the tangent bundle of the pseudodual manifold. We show that there can be mixing of

Yong Yao

The theory part of this paper is sketched as follows. Based on column stochastic average matrix $T_n$ selected as a basic substitution matrix, the method of advanced successive difference substitution is established. Then, a set of necessary and sufficient conditions for deciding positive semi-definite form on $\R^n_+$ is derived from this method. And furthe

J. C. Pandey, A. K. Srivastava

We report the observations of X-ray oscillations during the flare in a cool active star XI Boo for the first time. XI Boo was observed by EPIC/MOS of the XMM-Newton satellite. The X-ray light curve is investigated with wavelet and periodogram analyses. Both analyses clearly show oscillations of the period of 1019 s. We interpret these oscillations as a funda

George Field, Eric Blackman, Eric Keto

We further develop the model of molecular cloud fragmentation introduced in Field, Blackman and Keto (2007; FBK). We show that external pressure acting on fragments establishes a scale-dependent critical mass. Fragments with masses less than the critical value are confined largely by pressure, while those with masses greater than or equal to the critical val

C. J. Horowitz, D. K. Berry

Using molecular dynamics simulations, we determine the structure of neutron star crust made of rapid proton capture nucleosynthesis material. We find a regular body centered cubic lattice, even with the large number of impurities that are present. Low charge $Z$ impurities tend to occupy interstitial positions, while high $Z$ impurities tend to occupy substi

Pavel V. Shevchenko, Grigory Temnov

Typically, operational risk losses are reported above a threshold. Fitting data reported above a constant threshold is a well known and studied problem. However, in practice, the losses are scaled for business and other factors before the fitting and thus the threshold is varying across the scaled data sample. A reporting level may also change when a bank ch

Gareth W. Peters, Pavel V. Shevchenko, Mario V. Wüthrich

In this paper, we model dependence between operational risks by allowing risk profiles to evolve stochastically in time and to be dependent. This allows for a flexible correlation structure where the dependence between frequencies of different risk categories and between severities of different risk categories as well as within risk categories can be modeled

Daniel J. Price, Matthew R. Bate

We investigate the effects of magnetic fields and radiative protostellar feedback on the star formation process using self-gravitating radiation magnetohydrodynamical calculations. We present results from a series of calculations of the collapse of 50 solar mass molecular clouds with various magnetic field strengths and with and without radiative transfer. W

Abdusalom Karimov, Farrukh Mukhamedov

In the present paper, we study bundle convergence in $JW$- algebra and prove certain ergodic theorems with respect to such convergence. Moreover, conditional expectations of reversible $JW$-algebras are considered. Using such expectations, the convergence of supermartingales in such is established.

B. Militzer

The high temperature many-body density matrix is fundamental to path integral computation. The pair approximation, where the interaction part is written as a product of pair density matrices, is commonly used and is accurate to order tau squared, where tau is the step size in the imaginary time. Here we present a method for systems with Coulomb interactions

LAT Collaboration, A. A. Abdo

This is the first report of Fermi Gamma-ray Space Telescope observations of the quasar 3C 454.3, which has been undergoing pronounced long-term outbursts since 2000. The data from the Large Area Telescope (LAT), covering 2008 July 7 - October 6, indicate strong, highly variable gamma-ray emission with an average flux of ~3 x 10^{-6} photons cm^{-2} s^{-1}, f

O. Schuetz, G. Meeus, M. F. Sterzik, E. Peeters

We present new mid-infrared spectra for a sample of 15 targets (1 FU Orionis object, 4 Herbig Ae stars, 5 T Tauri stars and 5 Vega type stars), obtained with the TIMMI2 camera at La Silla Observatory (ESO). Three targets are members of the beta Pic moving group (HD 155555, HD 181296 and HD 319139). PAH bands are observed towards the T Tauri star HD 34700 and

Glennys R. Farrar, Ingyin Zaw, Andreas A. Berlind

We investigate several aspects of the correlations reported by the Pierre Auger Observatory between the highest energy cosmic rays (UHECRs) and galaxies in the Veron-Cetty Veron (VCV) catalog of AGNs. First, we quantify the extent of the inhomogeneity and impurity of the VCV catalog. Second, we determine how the correlation between the highest energy Auger U

O. Zeitouni, S. Zelditch

We prove an LDP for the empirical measure of complex zeros of a Gaussian random complex polynomial of degree N of one variable as N tends to infinity. The Gaussian measure is induced by an inner product defined by a smooth weight (Hermitian metric) $h$ and a Bernstein-Markov measure $ν$. The speed is N^2 and the the unique minimizer of the rate function $I$

Henri Anciaux

We prove that the only self-similar surfaces of Euclidean 3-space which are foliated by circles are the self-similar surfaces of revolution discovered by S. Angenent and that the only ruled, self-similar surfaces are the cylinders over planar self-similar curves.

James Charbonneau

We argue that topological vector currents may be the source of many phenomena in neutron stars: kicks, jets, toroidal fields and magnetic helicity. Topological vector currents exist because of the P-symmetry violation of the weak interaction. Kicks and helicity are both objects that transform as pseudovectors and thus require P-symmetry violation to manifest

Shuguang Wang

We study geometry on real gerbes in the spirit of Cheeger-Simons theory. The concepts of adaptations and holonomy forms are introduced for flat connections on real gerbes. Their relations to complex gerbes with connections are presented, as well as results in loop and map spaces.

Johan H. Knapen, Philip A. James

(Shortened) We consider the massive star formation properties, radial profiles, and atomic gas masses of those galaxies in our H alpha Galaxy Survey, a representative sample of the local Universe of 327 disk galaxies, that have close companion galaxies, in comparison with a matched control sample of galaxies without companions. We find that the presence of a

M. Ya. Amusia

It is demonstrated that non-locality and non-linearity of Hartree-Fock equations dramatically affect the properties of their solutions that essentially differ from solutions of Schr?dinger equation with a local potential. Namely, it acquires extra zeroes, has different coordinate asymptotic, violates so-called gauge-invariance, has different scattering phase

Alessio Serafini, Alex Retzker, Martin B. Plenio

We investigate the generation of squeezing and entanglement for the motional degrees of freedom of ions in linear traps, confined by time-varying and oscillating potentials, comprised of an DC and an AC component. We show that high degrees of squeezing and entanglement can be obtained by controlling either the DC or the AC trapping component (or both), and b

B. Barbiellini, A. Koizumi, P. E. Mijnarends, W. Al-Sawai

We have studied the [100]-[110] anisotropy of the Compton profile in the bilayer manganite. Quantitative agreement is found between theory and experiment with respect to the anisotropy in the two metallic phases (i.e. the low temperature ferromagnetic and the colossal magnetoresistant phase under a magnetic field of 7 T). Robust signatures of the metal-insul

C. P. McNally, J. Wadsley, H. M. P. Couchman

We demonstrate a significant difference in the angular momentum transport properties of galactic disks between regions in which the interstellar medium is single phase or two phase. Our study is motivated by observations of HI in extended galactic disks which indicate velocity dispersions of nonthermal origin, suggesting that turbulence in the gas may be con

Christopher J. Conselice, Jessica Arnold

We present an analysis of the structures, sizes, star formation rates, and local environmental properties of galaxies at z~4-6, utilising deep Hubble Space Telescope imaging of the Hubble Ultra Deep Field. The galaxies we study are selected with the Lyman-break drop-out technique, using galaxies which are B-,V-, and i-drops, which effectively selects UV brig

Konstadinos Sfetsos, Konstadinos Siampos

We prove that, general $\s$-models related by Poisson-Lie T-duality are quantum equivalent under one-loop renormalization group flow. We reveal general properties of the flows, we study the associated generalized coset models and provide explicit examples.

C. N. A. Willmer, G. H. Rieke, Emeric Le Floc&#39;h, J. L. Hinz

We combine new Spitzer Space Telescope observations in the mid- and far-infrared with SCUBA 850 micron observations to improve the measurement of dust temperatures, masses and luminosities for 11 galaxies of the SCUBA Local Universe Galaxy Survey (SLUGS). By fitting dust models we measure typical dust masses of 10E7.9 M_sol and dust luminosities of ~ 10E10 L

L Neves, G Lima, J Aguirre, F A Torres-Ruiz

We have implemented an optical quantum eraser with the aim of studying this phenomenon in the context of state discrimination. An interfering single photon is entangled with another one serving as a which-path marker. As a consequence, the visibility of the interference as well as the which-path information are constrained by the overlap (measured by the inn

Yen-Liang Chou, Michel Pleimling

We discuss a parameter free scaling relation that yields a complete data collapse for large classes of nonequilibrium growth processes. We illustrate the power of this new scaling relation through various growth models, as for example the competitive growth model RD/RDSR (random deposition/random deposition with surface diffusion) and the RSOS (restricted so

T. M. McQueen, T. Klimczuk, A. J. Williams, Q. Huang

Superconductivity in LaNiPO is disrupted by small (~5%) amounts of non-stoichiometry on the lanthanum site, even though the electronic contribution to the heat capacity increases with increasing non-stoichiometry. All samples also exhibit specific heat anomalies consistent with the presence of ferromagnetic spin fluctuations (Tsf ~ 14 K). Comparison of layer

P. A. Sturrock

The histogram formed from published capture-rate measurements for the GALLEX solar neutrino experiment is bimodal, showing two distinct peaks. On the other hand, the histogram formed from published measurements derived from the similar GNO experiment is unimodal, showing only one peak. However, the two experiments differ in run durations: GALLEX runs are eit

P. M. Gehring, H. Hiraka, C. Stock, S. -H. Lee

We have used neutron scattering techniques to characterize the diffuse scattering and lattice dynamics in single crystals of the relaxor PMN from 10K to 900K. We observed two distinct types of diffuse scattering. The first is weak, relatively temperature independent, persists to at least 900 K, and forms bow-tie-shaped patterns in reciprocal space centered o

Mark S. Veillette, Murad S. Taqqu

Let $\{D(s), s \geq 0\}$ be a non-decreasing Lévy process. The first-hitting time process $\{E(t) t \geq 0\}$ (which is sometimes referred to as an inverse subordinator) defined by $E(t) = \inf \{s: D(s) > t \}$ is a process which has arisen in many applications. Of particular interest is the mean first-hitting time $U(t)=\mathbb{E}E(t)$. This function chara

Vladislav B. Tadić

The convergence rate of stochastic gradient search is analyzed in this paper. Using arguments based on differential geometry and Lojasiewicz inequalities, tight bounds on the convergence rate of general stochastic gradient algorithms are derived. As opposed to the existing results, the results presented in this paper allow the objective function to have mult

Sebastian Perez, Katherine M. Blundell

A succession of near-IR spectroscopic observations, taken nightly throughout an entire cycle of SS433&#39;s orbit, reveal (i) the persistent signature of SS433&#39;s accretion disc, having a rotation speed of ~500 km/s, (ii) the presence of the circumbinary disc recently discovered at optical wavelengths by Blundell, Bowler and Schmidtobreick (2008) and (iii

Helge Krueger

I study the Lyapunov exponent and the integrated density of states for general Jacobi operators. The main result is that questions about these, can be reduced to questions about ergodic Jacobi operators. Then, I apply this to $a(n) = 1$ and $b(n) = f(n^ρ\pmod{1})$ for $ρ> 0$ not an integer, and to obtain a probabilistic version of the Denisov--Rakhmanov--Rem

Mark Agranovsky, Linh V. Nguyen

The transform under study is defined by integration of functions over spheres centered on a sphere. Such transform is of interest due to its applications in analysis and (thermoacoustic) tomography. The range of this transform has been described recently. Besides natural smoothness and support conditions, two type of conditions were involved: orthogonality c

Andrei Faraon, Jelena Vuckovic

We demonstrate a method to locally control the temperature of photonic crystal devices via micron-scale electrical heaters. The method is used to control the resonant frequency of InAs quantum dots strongly coupled to GaAs photonic crystal resonators. This technique enables independent control of large ensembles of photonic devices located on the same chip a

Olga V. Aryasova, Mykola I. Portenko

We formulate a martingale problem that describes a diffusion process in a multidimensional Euclidean space with a membrane located on a given smooth surface and having the properties of skewing and delaying. The theorem on the existence of no more than one solution to the problem is proved.

H. B. Nielsen

This article is about my memories from the discovery that the Veneziano model describes in fact interacting strings. I came to the understanding of that the dual or Veneziano model is really a model of strings independently of L. Susskind and Y. Nambu. A characteristic feature of my approach was that I used thinking of very high order &#34;fishnet&#34; or pl