November 2008 arXiv papers — page 27

Andrew J. Duncan, Tom G. Mackay, Akhlesh Lakhtakia

The linear strong--property--fluctuation theory (SPFT) was developed in order to estimate the constitutive parameters of certain homogenized composite materials (HCMs) in the long--wavelength regime. The component materials of the HCM were generally orthorhombic $mm2$ piezoelectric materials, which were randomly distributed as oriented ellipsoidal particles.

Alexey Boyarsky, Oleg Ruchayskiy

In this talk we review existing cosmological and astrophysical bounds on light (with the mass in keV - MeV range) and super-weakly interacting dark matter candidates. A particular attention is paid to the sterile neutrino DM candidate.

Vincent Guirardel, Gilbert Levitt

Let T be a tree with an action of a finitely generated group G. Given a suitable equivalence relation on the set of edge stabilizers of T (such as commensurability, co-elementarity in a relatively hyperbolic group, or commutation in a commutative transitive group), we define a tree of cylinders T_c. This tree only depends on the deformation space of T; in pa

Jiri Hejbal

The alternative approach to QCD analysis of the photon structure function $F_2^γ$ is presented. It differs from the conventional one by the presence of the terms which in conventional approach appear in higher orders. We show that this difference concerns also the photonic parton distribution functions. In the alternative approach, the complete LO analysis o

J. V. Cunha

The kinematic approach to cosmological tests provides a direct evidence to the present accelerating stage of the universe which does not depend on the validity of general relativity, as well as on the matter-energy content of the Universe. In this context, we consider here a linear two-parameter expansion for the decelerating parameter, $q(z)=q_0+q_1z$, wher

N. S. Kiselev, U. K. Roessler, A. N. Bogdanov, O. Hellwig

In antiferromagnetically coupled multilayers with perpendicular anisotropy unusual multidomain textures can be stabilized due to a close competition between long-range demagnetization fields and short-range interlayer exchange coupling. In particular, the formation and evolution of specific topologically stable planar defects within the antiferromagnetic gro

S. N. Nahar, J. Oelgoetz, A. K. Pradhan

The unified method for total electron-ion recombination is extended to study the dielectronic satellite (DES) lines. These lines, formed from radiative decay of autoionizing states, are highly sensitive temperature diagnostics of astrophysical and laboratory plasma sources. The computation of the unified recombination rates is based on the relativistic Breit

Johann G. Danzl, Manfred J. Mark, Elmar Haller, Mattias Gustavsson

One possibility for the creation of ultracold, high-phase-space-density quantum gases of molecules in the rovibrational ground state relies on first associating weakly-bound molecules from quantum-degenerate atomic gases on a Feshbach resonance and then transfering the molecules via several steps of coherent two-photon stimulated Raman adiabatic passage (STI

T. I. Mikhailova, B. Erdemchimeg, G. Kaminski, A. G. Artyukh

Asymmetry of the velocity distributions of projectile like fragments produced in heavy-ion collisions is discussed. The calculations made in transport model approach (the solution of Vlasov kinetic equation with the collisions term) are compared with experimental data for the reactions $^{22}Ne$ ($40 A\cdot$MeV) + $^{9}$Be and $^{18}$O ($35 A\cdot$MeV) + $^9

B. Neichel, T. Fusco, J. -M. Conan

Several Wide Field of view Adaptive Optics (WFAO) concepts like Multi-Conjugate AO (MCAO), Multi-Object AO (MOAO) or Ground-Layer AO (GLAO) are currently studied for the next generation of Extremely Large Telescopes (ELTs). All these concepts will use atmospheric tomography to reconstruct the turbulent phase volume. In this paper, we explore different recons

J. C. Fabris, S. V. B. Goncalves, H. E. S. Velten, W. Zimdahl

We model the cosmic medium as the mixture of a generalized Chaplygin gas and a pressureless matter component. Within a neo-Newtonian approach we compute the matter power spectrum. The 2dFGRS data are used to discriminate between unified models of the dark sector and different models, for which there is separate dark matter, in addition to that accounted for

Takashi Hamazaki

In the general matter composition where the multiple scalar fields and the multiple perfect fluids coexist, in the leading order of the gradient expansion, we construct all of the solutions of the nonlinear evolutions of the locally homogeneous universe. From the momentum constraint, we derive the constraints which the solution constants of the locally homog

Ronan Quarez

First, we show that Sturm algorithm and Sylvester algorithm, which compute the number of real roots of a given univariate polynomial, lead to two dual tridiagonal determinantal representations of the polynomial. Next, we show that the number of real roots of a polynomial given by a tridiagonal determinantal representation is greater than the signature of thi

Syksy Rasanen

Observations are inconsistent with a homogeneous and isotropic universe with ordinary matter and gravity. The universe is far from exact homogeneity and isotropy at late times, and the effect of the non-linear structures has to be quantified before concluding that new physics is needed. We explain how structure formation can lead to accelerated expansion, an

Christoph Friedrich, Arno Schindlmayr, Stefan Bluegel

We derive formulas for the Coulomb matrix within the full-potential linearized augmented-plane-wave (FLAPW) method. The Coulomb matrix is a central ingredient in implementations of many-body perturbation theory, such as the Hartree-Fock and GW approximations for the electronic self-energy or the random-phase approximation for the dielectric function. It is r

Andreas Haungs

The ARENA08 conference, held in Rome in June 2008, gave an almost complete overview on applications of the new techniques radio and acoustic detection of electromagnetic showers generated by high-energy cosmic particles in air or in dielectric media. There are vast activities all over the world, and the progress is remarkable. This was displayed by more than

E. F. Moreno, F. A. Schaposnik

We exploit the relationship between the space components of the energy-momentum tensor and the supercurrent to discuss the connection between the BPS equations and the vanishing of the components of the stress tensor in various supersymmetric theories with solitons. Using the fact that certain combination of supercharges annihilate BPS states, we show that $

C. Marinoni, L. Guzzo, A. Cappi, O. Le Fevre

We study the evolution of the low-order moments of the galaxy overdensity distribution over the redshift interval 0.7<z<1.5. We find that the variance and the normalized skewness evolve over this redshift interval in a way that is remarkably consistent with predictions of first- and second-order perturbation theory. This finding confirms the standard gravita

Moritz Boeck, Manfred Hanke, Joern Wilms, Victoria Grinberg

In 2005 February we observed Cygnus X-1 over a period of 10 days quasi-continuously with the Rossi X-ray Timing Explorer and the Ryle telescope. We present the results of the spectral and timing analysis on a timescale of 90 min and show that the behavior of Cyg X-1 is similar to that found during our years long monitoring campaign. As a highlight we present

Tali Kaufman, Shachar Lovett

In this work we study the list-decoding size of Reed-Muller codes. Given a received word and a distance parameter, we are interested in bounding the size of the list of Reed-Muller codewords that are within that distance from the received word. Previous bounds of Gopalan, Klivans and Zuckerman \cite{GKZ08} on the list size of Reed-Muller codes apply only up

N. Cundy, M. Göckeler, R. Horsley, T. Kaltenbrunner

We discuss an action in which the fermion matrix has single level stout smearing for the hopping terms together with unsmeared links for the clover term. With the (tree level) Symanzik improved gluon action this constitutes the Stout Link Non-perturbative Clover or SLiNC action. To cancel O(a) terms the clover coefficient, csw, has to be tuned. We present he

CALICE Collaboration

A prototype Silicon-Tungsten electromagnetic calorimeter (ECAL) for an International Linear Collider (ILC) detector was installed and tested during summer and autumn 2006 at CERN. The detector had 6480 silicon pads of dimension 1x1 cm^2. Data were collected with electron beams in the energy range 6 to 45 GeV. The analysis described in this paper focuses on e

Mihnea Colţoiu

We give a short proof for the Hartogs&#39;s extension theorem on (n-1)-complete complex spaces.

N. Pompeo, R. Rogai, E. Silva, A. Augieri

In order to study the vortex pinning determined by artificially introduced pinning centers in the small-vortex displacement regime, we measured the microwave surface impedance at 47.7 GHz in the mixed state of YBa$_{2}$Cu$_{3}$O$_{7-δ}$ thin films, where sub-micrometric BaZrO$_3$ particles have been incorporated. As a function of the BaZrO$_3$ content, we ob

P. Belli, R. Bernabei, F. Cappella, R. Cerulli

Double beta processes in 64-Zn, 70-Zn, 180-W, and 186-W have been searched for with the help of large volume (0.1-0.7 kg) low background ZnWO4 crystal scintillators at the Gran Sasso National Laboratories of the INFN. Total time of measurements exceeds 10 thousands hours. New improved half-life limits on double electron capture and electron capture with posi

Manoj K. Singh, Ram S. Katiyar, W. Prellier, J. F. Scott

Low-temperature magnetic properties of epitaxial BiFeO3 thin films grown on (111)-SrTiO3 substrates have been studied. ZFC and FC magnetization curves show a large discrepency beginning at a characteristic temperature Tf that is dependent on the magnetic-field strengh. Tf(H) varies according to the well known de Aleimda-Thouless line (varies in Hexp(2/3)) su

Stefan Jordan

Gaia is a satellite mission of the ESA, aiming at absolute astrometric measurements of about one billion stars (all stars down to 20th magnitude, with unprecedented accuracy. Additionally, magnitudes and colors will be obtained for all these stars, while radial-velocities and spectral properties will be determined only for bright objects (V<17.5). At 15th ma

N. M. Agababyan, V. V. Ammosov, M. Atayan, N. Grigoryan

The total yields of the all well-established light mesonic resonances (up to the $ϕ$(1020) meson) are estimated in neutrinonuclear interactions at < E_nu > = 10 GeV, using the data obtained with SKAT bubble chamber. For some resonances, the yields in the forward and backward hemispheres in the hadronic c.m.s. are also extracted. From the comparison of the ob

Monica Pozzo, Dario Alfe`

The kinetics of hydrogen absorption by magnesium bulk is affected by two main activated processes: the dissociation of the H$_2$ molecule and the diffusion of atomic H into the bulk. In order to have fast absorption kinetics both activated processed need to have a low barrier. Here we report a systematic ab-initio density functional theory investigation of H

A. J. Liljeström, M. J. Korpi, P. J. Käpylä, A. Brandenburg

We present local numerical models of accretion disk turbulence driven by the magnetorotational instability with varying shear rate. The resulting turbulent stresses are compared with predictions of a closure model in which triple correlations are modelled in terms of quadratic correlations. This local model uses five nondimensional parameters to describe the

Xavier Caruso

Torsion semi-stable representations can be constructed and studied using Breuil modules. In this paper, we define the notion of pylonet and prove that some categories of Breuil modules naturally define pylonets. As a consequence, we are able to define full subcategories of Breuil&#39;s categories with very nice properties (in particular, they are abelian). I

Georges Meynet, Patrick Eggenberger, Nami Mowlavi, Andre Maeder

Starting from a few topical astrophysical questions which require the knowledge of the age of Pop I stars, we discuss the needed precision on the age in order to make progresses in these areas of research. Then we review the effects of various inputs of the stellar models on the age determination and try to identify those affecting the most the lifetimes of

Jens C. Zahnow, Rafael D. Vilela, Ulrike Feudel, Tamas Tel

Inertial particles advected in chaotic flows often accumulate in strange attractors. While moving in these fractal sets they usually approach each other and collide. Here we consider inertial particles aggregating upon collision. The new particles formed in this process are larger and follow the equation of motion with a new parameter. These particles can in

A. A. Shkalikov, O. A. Veliev

The paper deals with the Sturm-Liouville operator $$ Ly=-y^{\prime\prime}+q(x)y,\qquad x\in\lbrack0,1], $$ generated in the space $L_{2}=L_{2}[0,1]$ by periodic or antiperiodic boundary conditions. Several theorems on Riesz basis property of the root functions of the operator $L$ are proved. One of the main results is the following. \textsl{Let $q$ belong to

Fraser Lewis, David M. Russell, Rob P. Fender, Paul Roche

The Faulkes Telescope Project is an educational and research arm of the Las Cumbres Observatory Global Telescope Network (LCOGTN). It has two 2-metre robotic telescopes, located at Haleakala on Maui (FT North) and Siding Spring in Australia (FT South). It is planned for these telescopes to be complemented by a research network of eighteen 1-metre telescopes,

Enrique Villanova-Vidal, Thomas Palberg, Hans Joachim Schöpe, Hartmut Löwen

We report on a novel and flexible experiment to investigate the non-equilibrium melting behaviour of model crystals made from charged colloidal spheres. In a slit geometry polycrystalline material formed in a low salt region is driven by hydrostatic pressure up an evolving gradient in salt concentration and melts at large salt concentration. Depending on par

L. Coccato, O. Gerhard, M. Arnaboldi, P. Das

We present first results of a study of the halo kinematics for a sample of early type galaxies using planetary nebulae (PNe) as kinematical tracers. PNe allow to extend up to several effective radii (Re) the information from absorption line kinematics (confined to within 1 or 2 Re), providing valuable information and constraints for merger simulations and ga

Julian Rincon, A. A. Aligia, K. Hallberg

We calculate the conductance through rings with few sites $L$ described by the $t-J$ model, threaded by a magnetic flux $Φ$ and weakly coupled to conducting leads at two arbitrary sites. The model can describe a circular array of quantum dots with large charging energy $U$ in comparison with the nearest-neighbor hopping $t$. We determine analytically the par

Yuri A. Genenko

A mechanism of point defect migration triggered by local depolarization fields is shown to explain some still inexplicable features of aging in acceptor doped ferroelectrics. A drift-diffusion model of the coupled charged defect transport and electrostatic field relaxation within a two-dimensional domain configuration is treated numerically and analytically.

J. Vranjes, S. Poedts

Mecheri and Marsch concluded that drift currents caused by density gradients can serve as an energy source for a plasma instability, in particular for the excitation of ion-cyclotron waves in the solar corona. It is pointed out that these authors overlooked some fundamental properties of the drift motion in inhomogeneous plasmas. The calculation is repeated,

Alexander Kirillov, Jaimal Thind

Let g be a Lie algebra of type A,D,E with fixed Cartan subalgebra h, root system R and Weyl group W. We show that a choice of Coxeter element C gives a root basis for g. Moreover we show that this root basis gives a purely combinatorial construction of g, where root vectors correspond to vertices of a certain quiver $Gammahat$, and show that with respect to

Thomas Palberg, Holger Reiber, Tetyana Köller, Martin Medebach

In soft matter structure couples to flow and vice versa. Complementary to structural investigations, we here are interested in the determination of particle velocities of charged colloidal suspensions of different structure under flow. In a combined effort of theory and experiment we determine the Fourier transform of the super-heterodyne field auto-correlat

Linda I. Uruchurtu

The four-point correlation function of two 1/2 BPS primaries of conformal weight $Δ=2$ and two 1/2-BPS primaries of conformal weight $Δ=n$ is calculated in the large &#39;t Hooft, large $N$ limit. These operators are dual to Kaluza-Klein supergravity fields $s_k$ with masses $m^2=-4$ and $m^2=n(n-4)$. Given that the existing formalism for evaluating sums of

O. Petruk, G. Dubner, G. Castelletti, F. Bocchino

A number of important processes taking place around strong shocks in supernova remnants (SNRs) depend on the shock obliquity. The measured synchrotron flux is a function of the aspect angle between interstellar magnetic field (ISMF) and the line of sight. Thus a model of non-thermal emission from SNRs should account for the orientation of the ambient magneti

R. Landi, J. B. Stephen, N. Masetti, D. Grupe

The third INTEGRAL/IBIS survey has revealed several new hard X-ray sources, which are still unclassified. To identify these sources, we need to find their counterparts at other wavelengths and then study their nature. The capability of XRT on board Swift to localize the sources with a positional accuracy of few arcseconds allows the search for optical/UV, in

Maite Grau, Jordi Villadelprat

Pleshkan proved in 1969 that, up to a linear transformation and a constant rescaling of time, there are four isochrones in the family of cubic centers with homogeneous nonlinearities $\mathscr C_3.$ In this paper we prove that if we perturb any of these isochrones inside $\mathscr C_3,$ then at most two critical periods bifurcate from its period annulus. Mor

Paul Siddons, Nia C Bell, Yifei Cai, Charles S Adams

The ability to control the speed and polarisation of light pulses will allow for faster data flow in optical networks of the future. Optical delay and switching have been achieved using slow-light techniques in various media, including atomic vapour. Most of these vapour schemes utilise resonant narrowband techniques for optical switching, but suffer the dra

J. Farjas, P. Roura

A simple numerical model which calculates the kinetics of crystallization involving randomly distributed nucleation and isotropic growth is presented. The model can be applied to different thermal histories and no restrictions are imposed on the time and the temperature dependencies of the nucleation and growth rates. We also develop an algorithm which evalu

S. Bariši\&#39; c, O. S. Bariši\&#39; c

The Bechgaard salts and the high T$_c$ cuprates are described by two and three band models, respectively, with the lowest band (nearly) half filled. In organics the interactions are small, while in cuprates the repulsion $U_d$ on the Cu site is the largest energy. The Mott AF state is stable in undoped materials in both cases. In the metallic phase of cuprat

Christophe Eyral, Mutsuo Oka

The existence of Alexander-equivalent Zariski pairs dealing with irreducible curves of degree 6 was proved by A. Degtyarev. However, up to now, no explicit example of such a pair was available (only the existence was known). In this paper, we construct the first concrete example.

J. Farjas, P. Roura

The kinetics and microstructure of solid-phase crystallization under continuous heating conditions and random distribution of nuclei are analyzed. An Arrhenius temperature dependence is assumed for both nucleation and growth rates. Under these circumstances, the system has a scaling law such that the behavior of the scaled system is independent of the heatin

T. Sahihi, H. Eshraghi, A. Mahdipour-Shirayeh

A special version of multi--dimensional simple waves given in [G. Boillat, {\it J. Math. Phys.} {\bf 11}, 1482-3 (1970)] and [G.M. Webb, R. Ratkiewicz, M. Brio and G.P. Zank, {\it J. Plasma Phys.} {\bf 59}, 417-460 (1998)] is employed for fully relativistic fluid and plasma flows. Three essential modes: vortex, entropy and sound modes are derived where each

Yuri V. Andreyev, Alexander S. Dmitriev, Andrey V. Kletsov

Effect of multipath amplification is found in ultrawideband wireless communication systems with chaotic carrier, whereas information is transmitted with chaotic radio pulses. This effect is observed in multipath environment (residence, office, industrial or other indoor space). It exhibits itself through an increase of signal power at the receiver input with

D. K. Huynh, J. P. Keating, N. C. Snaith

It is believed that, in the limit as the conductor tends to infinity, correlations between the zeros of elliptic curve $L$-functions averaged within families follow the distribution laws of the eigenvalues of random matrices drawn from the orthogonal group. For test functions with restricted support, this is known to be the true for the one- and two-level de

S. Lowitzer, D. Ködderitzsch, H. Ebert, J. B. Staunton

Experimental measurements of the residual resistivity $ρ(x)$ of the binary alloy system Fe$_{1-x}$Cr$_x$ have shown an anomalous concentration dependence which deviates significantly from Nordheim&#39;s rule. In the low ($x < 10%$) Cr concentration regime the resistivity has been found to increase linearly with $x$ until $\approx$ 10% Cr where the resistivit

G. Lambiase, G. Papini, G. Scarpetta

We discuss a model in which a recently reported modulation in the decay of the hydrogenlike ions ${}^{140}$Pr$^{58 +}$ and ${}^{142}$Pm$^{60 +}$ arises from the coupling of rotation to the spin of electron and nuclei (Thomas precession). A similar model describes the electron modulation in muon $ g-2$ experiments correctly. Agreement with the GSI experimenta

V. Schwämmle, P. M. C. de Oliveira

Human history leaves fingerprints in human languages. Little is known over language evolution and its study is of great importance. Here, we construct a simple stochastic model and compare its results to statistical data of real languages. The model bases on the recent findings that language changes occur independently on the population size. We find agreeme

J Minár, J Braun, S Bornemann, H Ebert

The half-Heusler alloy NiMnSb is one of the local-moment ferromagnets with unique properties for future applications. Band structure calculations predict exclusively majority bands at the Fermi level, thus indicating {100%} spin polarization there. As one thinks about applications and the design of functional materials, the influence of chemical disorder in

Peter Jagers, Serik Sagitov

The simple Galton--Watson process describes populations where individuals live one season and are then replaced by a random number of children. It can also be viewed as a way of generating random trees, each vertex being an individual of the family tree. This viewpoint has led to new insights and a revival of classical theory. We show how a similar reinterpr

C. Franchini, R. Podloucky, F. Allegretti, F. Li

Using different experimental techniques combined with density functional based theoretical methods we have explored the formation of interface-stabilized manganese oxide structures grown on Pd(100) at (sub)monolayer coverage. Amongst the multitude of phases experimentally observed we focus our attention on four structures which can be classified into two dis

Xing Huang, Leonard Parker

In previous work on the quantum mechanics of an atom freely falling in a general curved background spacetime, the metric was taken to be sufficiently slowly varying on time scales relevant to atomic transitions that time derivatives of the metric in the vicinity of the atom could be neglected. However, when the time-dependence of the metric cannot be neglect

A. Jakovac

In the O(N) model for the large N expansion one needs resummation which makes the renormalization of the model difficult. In the paper it is discussed, how can one perform a consistent perturbation theory at zero as well as at finite temperature with the help of momentum dependent renormalization schemes.

S. Baruah, G. Audi, K. Blaum, M. Dworschak

High-precision mass measurements on neutron-rich zinc isotopes 71m,72-81Zn have been performed with the Penning trap mass spectrometer ISOLTRAP. For the first time the mass of 81Zn has been experimentally determined. This makes 80Zn the first of the few major waiting points along the path of the astrophysical rapid neutron capture process where neutron separ

C. -K. Yun, B. Kahng, D. Kim

In the reaction-diffusion process $A+B \to \varnothing$ on random scale-free (SF) networks with the degree exponent $γ$, the particle density decays with time in a power law with an exponent $α$ when initial densities of each species are the same. The exponent $α$ is $α> 1$ for $2 < γ< 3$ and $α=1$ for $γ\ge 3$. Here, we examine the reaction process on fract

A. Abdollahi, A. Rejali, A. Yousofzadeh

The concept of configuration was first introduced by Rosenblatt and Willis to give a condition for amenability of groups. We show that if $G_1$ and $G_2$ have the same configuration sets and $H_1$ is a normal subgroup of $G_1$ with abelian quotient, then there is a normal subgroup $H_2$ of $G_2$ such that $\frac{G_1}{H_1}\cong\frac{G_2}{H_2}.$ Also configura

Satya N. Majumdar, Massimo Vergassola

We present a simple Coulomb gas method to calculate analytically the probability of rare events where the maximum eigenvalue of a random matrix is much larger than its typical value. The large deviation function that characterizes this probability is computed explicitly for Wishart and Gaussian ensembles. The method is quite general and applies to other rela

Vu The Khoi

In this paper, we give a parameterization of the SU(2,1) representation space of the Brieskorn homology spheres using the trace coordinates. As applications, we give an example which shows that the orbifold Toledo invariant in \cite{krebs} does not distinguish the connected components of the PU(2,1) representation space.

NNPDF Collaboration, Juan Rojo, Richard D. Ball, Luigi Del Debbio

We present recent progress within the NNPDF parton analysis framework. After a brief review of the results from the DIS NNPDF analysis, NNPDF1.0, we discuss results from an updated analysis with independent parametrizations for the strange and anti-strange distributions, denoted by NNPDF1.1. We examine the phenomenological implications of this improved analy

N. Dupuis, K. Sengupta

We review the superfluid to Mott-insulator transition of cold atoms in optical lattices. The experimental signatures of the transition are discussed and the RPA theory of the Bose-Hubbard model briefly described. We point out that the critical behavior at the transition, as well as the prediction by the RPA theory of a gapped mode (besides the Bogoliubov sou

K. Kim, B. Kahng, D. Kim

Packet traffic in complex networks undergoes the jamming transition from free-flow to congested state as the number of packets in the system increases. Here we study such jamming transition when queues are operated by the priority queuing protocol and packets are guided by the dynamic routing protocol. We introduce a minimal model in which there are two type

L. Tiator, M. Vanderhaeghen

Using recent experimental data, we analyze the electromagnetic transition from the nucleon to the P11(1440) resonance. From the resulting empirical transition form factors, we map out the quark transverse charge densities which induce the N to P11(1440) transition. It is found that the transition from the proton to its first radially excited state is dominat

Mohammad Khorrami, Amir Aghamohammadi

A nonuniform extension of the Glauber model on a one-dimensional lattice with boundaries is investigated. Based on detailed balance, reaction rates are proposed for the system. The static behavior of the system is investigated. It is shown that there are cases where the system exhibits a static phase transition, which is a change of behavior of the static pr

F. Gaspari, I. M. Kupchak, A. I. Shkrebtii, J. M. Perz

As molecular dynamics is increasingly used to characterize non-crystalline materials, it is crucial to verify that the numerical model is accurate enough, consistent with experimental data and can be used to extract various characteristics of disordered systems. In most cases the only derived property used to test the &#34;realism&#34; of the models has been

Karim Lounici

We propose a generalized version of the Dantzig selector. We show that it satisfies sparsity oracle inequalities in prediction and estimation. We consider then the particular case of high-dimensional linear regression model selection with the Huber loss function. In this case we derive the sup-norm convergence rate and the sign concentration property of the

Fedja Orucevic, Jean Hare, Valérie Lefèvre-Seguin

We report on light emission from high-Q neodymium-implanted silica microtoroids. Following the description of the fabrication process of microtoroids, neodymium light emission is analysed. This emission is coupled to various cavity modes. Using evanescent wave coupling we achieve selective detection of Whispering Gallery Modes of a microtoroid.

A. Calogero, R. Pini

We investigate the notion of H-subdifferential and H-normal map of a function on the Heisenberg group, based on its sub-Riemannian structure. In particular, a characterization of the convexity of a function is given via the nonemptiness of the H-subdifferential at every point.

Stéphane Crépey, Anis Matoussi

It is now established that under quite general circumstances, including in models with jumps, the existence of a solution to a reflected BSDE is guaranteed under mild conditions, whereas the existence of a solution to a doubly reflected BSDE is essentially equivalent to the so-called Mokobodski condition. As for uniqueness of solutions, this holds under mild

Z. Q. Qu

Ways to give medium- and short-term predictions of solar flares are proposed according to the statistical analysis of events during solar cycle 23. On one hand, the time distribution of both C and M class flares shows two main periods of 13.2 and 26.4 months in this cycle by wavelet analysis. On the other hand, active regions of specific magnetic configurati

Sergei A. Trushkin, Nikolaj N. Bursov, Nikolaj A. Nizhelskij

We discuss flaring variability of radio emission of microquasars, measured in monitoring programs with the RATAN-600 radio telescope. We carried out a multi-frequency (1-30 GHz) daily monitoring of the radio flux variability of the microquasars SS433, GRS1915+105, and Cyg X-3 during the recent sets in 2005-2007. A lot of bright short-time flares were detecte

Hiroki Nakano, Akira Terai

We propose two methods of estimating a systematic error in extrapolation to the infinite-size limit in the study of measuring the Haldane gaps of the one-dimensional Heisenberg antiferromagnet with the integer spin up to S=5. The finite-size gaps obtained by numerical diagonalizations based on Lanczos algorithm are presented for sizes that have not previousl

Douglas A. Bennett, Luigi Longobardi, Vijay Patel, Wei Chen

We report measurements of coherence times of an rf SQUID qubit using pulsed microwaves and rapid flux pulses. The modified rf SQUID, described by an double-well potential, has independent, in situ, controls for the tilt and barrier height of the potential. The decay of coherent oscillations is dominated by the lifetime of the excited state and low frequency

Pokman Cheung

This is the Ph.D. dissertation of the author. The project has been motivated by the conjecture that the Hopkins-Miller tmf spectrum can be described in terms of `spaces&#39; of conformal field theories. In this dissertation, spaces of field theories are constructed as classifying spaces of categories whose objects are certain types of field theories. If such

Fumiko Yamada, Yasuyuki Ishii, Takao Suzuki, Teiichiro Matsuzaki

Magnetization measurements under a hydrostatic pressure of P = 1.4 GPa were performed on the coupled spin dimer system TlCuCl_3, which exhibits a pressure-induced quantum phase transition from a gapped singlet state to an antiferromagnetic state at P_c = 0.042 GPa. Antiferromagnetic ordering with ordered moments parallel to the ac plane was observed at T_N =

David Jewitt

Six hot topics in modern planetary astronomy are described: 1) lightcurves and densities of small bodies 2) colors of Kuiper belt objects and the distribution of the ultrared matter 3) spectroscopy and the crystallinity of ice in the outer Solar system 4) irregular satellites of the giant planets 5) the Main Belt Comets and 6) comets and meteor stream parent

Shoji Yokura

In 1981 W. Fulton and R. MacPherson introduced the notion of bivariant theory (BT), which is a sophisticated unification of covariant theories and contravariant theories. This is for the study of singular spaces. In 2001 M. Levine and F. Morel introduced the notion of algebraic cobordism, which is a universal oriented Borel-Moore functor with products (OBMF)

Antonio Pipino, Francesca Matteucci

The time-scales of chemical enrichment are fundamental to understand the evolution of abundances and abundance ratios in galaxies. In particular, the time-scales for the enrichment by SNe II and SNe Ia are crucial in interpreting the evolution of abundance ratios such as [alpha/Fe]. In fact, the alpha-elements are produced mainly by SNe II on time-scales of

C. Royon, G. Beuf, R. Peschanski, D. Salek

Using the &#34;Quality Factor&#34; (QF) method, we analyse the scaling properties of deep-inelastic processes at HERA and fixed target experiments for x<10^{-2}.

Emmanuel Allaud, Victor Devoue

In this paper we give a meaning to the nonlinear characteristic Cauchy problem for the Wave Equation in base form by replacing it by a family of non-characteristic problems in an appropriate algebra of generalized functions. We prove existence of a solution and we precise how it depends on the choice made. We also check that in the classical case (non-charac

Mark Yashar, Brandon Bozek, Augusta Abrahamse, Andreas Albrecht

We report on the results of a Markov Chain Monte Carlo (MCMC) analysis of an inverse power law (IPL) quintessence model using the Dark Energy Task Force (DETF) simulated data sets as a representation of future dark energy experiments. We generate simulated data sets for a Lambda-CDM background cosmology as well as a case where the dark energy is provided by

Martin Mevissen, Kosuke Yokoyama, Nobuki Takayama

We propose a general algorithm to enumerate all solutions of a zero-dimensional polynomial system with respect to a given cost function. The algorithm is developed and is used to study a polynomial system obtained by discretizing the steady cavity flow problem in two dimensions. The key technique on which our algorithm is based is to solve polynomial optimiz

Parsa Bakhtary

We establish a formula which decomposes the cohomologies of various sheaves on a simple normal crossings divisor (SNC) $D$ in terms of the simplicial cohomologies of the dual complex $Δ(D)$ with coefficients in a presheaf of vector spaces. This presheaf consists precisely of the corresponding cohomology data on the components of $D$ and on their intersection

A. M. Ghezelbash

We investigate the construction of five-dimensional supergravity solutions that don&#39;t have any tri-holomorphic U(1) isometries. We construct a class of solutions that in various limits of parameters reduces to many of previously constructed five-dimensional supergravity solutions based on both hyper-Kahler base spaces that can be put into a Gibbons-Hawki

Kjetil M. D Hals, Anh Kiet Nguyen, Arne Brataas

We consider current-induced domain wall motion and, the reciprocal process, moving domain wall-induced current. The associated Onsager coefficients are expressed in terms of scattering matrices. Uncommonly, in (Ga,Mn)As, the effective Gilbert damping coefficient $α_w$ and the effective out-of-plane spin transfer torque parameter $β_w$ are dominated by spin-o

Marcos Rigol, George G. Batrouni, Valery G. Rousseau, Richard T. Scalettar

We use quantum Monte Carlo simulations to obtain zero-temperature state diagrams for strongly correlated lattice bosons in one and two dimensions under the influence of a harmonic confining potential. Since harmonic traps generate a coexistence of superfluid and Mott insulating domains, we use local quantities such as the quantum fluctuations of the density

S. T. Scully, F. W. Stecker

There has been much interest in possible violations of Lorentz invariance, particularly motivated by quantum gravity theories. It has been suggested that a small amount of Lorentz invariance violation (LIV) could turn off photomeson interactions of ultrahigh energy cosmic rays (UHECRs) with photons of the cosmic background radiation and thereby eliminate the

Abraham Loeb

The cosmological background of ionizing radiation has been dominated by quasars once the Universe aged by ~2 billion years. At earlier times (redshifts z>3), the observed abundance of bright quasars declined sharply, implying that cosmic hydrogen was reionized by stars instead. Here, we explain the physical origin of the transition between the dominance of s

Josep C. Pàmies, Angelo Cacciuto, Daan Frenkel

We report the phase diagram of interpenetrating Hertzian spheres. The Hertz potential is purely repulsive, bounded at zero separation, and decreases monotonically as a power law with exponent 5/2, vanishing at the overlapping threshold. This simple functional describes the elastic interaction of weakly deformable bodies and, therefore, it is a reliable physi

Daniel Podolsky, Arun Paramekanti, Yong Baek Kim, T. Senthil

We study a bandwidth controlled Mott metal-insulator transition (MIT) between a Fermi liquid metal and a quantum spin-liquid insulator at half-filling in three dimensions (3D). Using a slave rotor approach, and incorporating gauge field fluctuations, we find a continuous MIT and discuss the finite temperature crossovers around this critical point. We show th

Chad Giusti

We construct a new type of geometric knot theory, plumbers&#39; knots, and solve the problems of distinguishing and enumerating such knots at a fixed level of complexity. (v2) Minor edits, added theorem 3.18. (v3) Substantial revisions, essentially completely rewritten in places.

Alberto Nicolis, Riccardo Rattazzi, Enrico Trincherini

In the DGP model, the ``self-accelerating&#39;&#39; solution is plagued by a ghost instability, which makes the solution untenable. This fact as well as all interesting departures from GR are fully captured by a four-dimensional effective Lagrangian, valid at distances smaller than the present Hubble scale. The 4D effective theory involves a relativistic sca