March 2008 arXiv papers — page 18

J. Delahaye, T. Grenet, F. Gay

We perform electrical field effect measurements at 4 K on insulating granular aluminium thin films. When the samples size is reduced below 100 micrometers, reproducible and stable conductance fluctuations are seen as a function of the gate voltage. Our results suggest that these fluctuations reflect the incomplete self-averaging of largely distributed micros

Florian Huc, Ignasi Sau Valls, Janez Zerovnik

The packet routing problem plays an essential role in communication networks. It involves how to transfer data from some origins to some destinations within a reasonable amount of time. In the $(\ell,k)$-routing problem, each node can send at most $\ell$ packets and receive at most $k$ packets. Permutation routing is the particular case $\ell=k=1$. In the $r

Jérôme Renault

We consider dynamic programming problems with a large time horizon, and give sufficient conditions for the existence of the uniform value. As a consequence, we obtain an existence result when the state space is precompact, payoffs are uniformly continuous and the transition correspondence is non expansive. In the same spirit, we give an existence result for

J. P. Bergfield, C. A. Stafford

We develop a theoretical approach to quantum transport through single conjugated organic molecules that accurately accounts for all molecular excited and ground states via a semi-empirical many-body molecular Hamiltonian. We then calculate the linear and non-linear transport properties of a benzenedithiol molecule covalently bonded to two gold electrodes at

Neil Donaldson, Chuu-Lian Terng

E. Cartan proved that conformally flat hypersurfaces in S^{n+1} for n>3 have at most two distinct principal curvatures and locally envelop a one-parameter family of (n-1)-spheres. We prove that the Gauss-Codazzi equation for conformally flat hypersurfaces in S^4 is a soliton equation, and use a dressing action from soliton theory to construct geometric Ribau

Tsuyoshi Kobayashi, Yo'av Rieck

We prove (Theorem~1.5) that there exists a constant $Λ> 0$ so that if $M$ is a $(μ,d)$-generic complete hyperbolic 3-manifold of volume $\vol[M] < \infty$ and $Σ\subset M$ is a Heegaard surface of genus $g(Σ) > Λ\vol[M]$, then $d(Σ) \leq 2$, where $d(Σ)$ denotes the distance of $Σ$ as defined by Hempel. The key for the proof of the main result is Theorem~1.8

J. I. Read, G. Lake, O. Agertz, Victor P. Debattista

In a LCDM cosmology, the Milky Way accretes satellites into the stellar disc. We use cosmological simulations to assess the frequency of near disc plane and higher inclination accretion events, and collisionless simulations of satellite mergers to quantify the final state of the accreted material and the effect on the thin disc. On average, a Milky Way-sized

Suyoung Choi, Mikiya Masuda, Dong Youp Suh

A quasitoric manifold (resp. a small cover) is a $2n$-dimensional (resp. an $n$-dimensional) smooth closed manifold with an effective locally standard action of $(S^1)^n$ (resp. $(\mathbb Z_2)^n$) whose orbit space is combinatorially an $n$-dimensional simple convex polytope $P$. In this paper we study them when $P$ is a product of simplices. A generalized B

D. L. Zhou

In a system of $n$ quantum particles, the correlations are classified into a series of irreducible $k$-particle correlations ($2\le k\le n$), where the irreducible $k$-particle correlation is the correlation appearing in the states of $k$ particles but not existing in the states of $k-1$ particles. A measure of the degree of irreducible $k$-particle correlat

Apoorva Khare

In this note, we find a sharp bound for the minimal number (or in general, indexing set) of subspaces of a fixed (finite) codimension needed to cover any vector space V over any field. If V is a finite set, this is related to the problem of partitioning V into subspaces.

Andrei Alexandru, Ivan Horvath, Keh-Fei Liu

It was recently proposed by the second author to consider lattice formulations of QCD in which complete actions, including the gauge part, are built explicitly from a given Dirac operator D. In a simple example of such theory, the gauge action is proportional to the trace of Ginsparg-Wilson operator D chosen to define the quark dynamics. This construction re

Kiyoshi Kamimura, Daisuke Shiseki

We discuss a rigid string model proposed by Casalbuoni and Longhi. Constraints for the massive states are solved to find the physical states and the mass spectrum. We also find its supersymmetric extension with the kappa symmetry. The supersymmetry transformations are found starting from on-shell transformations using the Dirac bracket.

Nathalie Deruelle, Misao Sasaki, Yuuiti Sendouda

In gravity theories derived from a f(R) Lagrangian, matter is usually supposed to be minimally coupled to the metric, which hence defines a ``Jordan frame.&#39;&#39; However, since the field equations are fourth order, gravity possesses an extra degree of freedom on top of the standard graviton, as is manifest from its equivalent description in the conformal

I. I. Mazin, D. J. Singh, M. D. Johannes, M. H. Du

We argue that the newly discovered superconductivity in a nearly magnetic, Fe-based layered compound is unconventional and mediated by antiferromagnetic spin fluctuations, though different from the usual superexchange and specific to this compound. This resulting state is an example of extended s-wave pairing with a sign reversal of the order parameter betwe

T. S. Konar, S. Paul

In this paper we tried a different approach to work out the integrals of e^(x^n) and e^(-x^n). Integration by parts shows a nice pattern which can be reduced to a form of series. We have shown both the indefinite and definite integrals of the functions mentioned along with some essential properties e.g. conditions of convergence of the series. Further more,

Francesco Calabró, Antonio Corbo Esposito

This work is devoted to the study of integration with respect to binomial measures. We develop interpolatory quadrature rules and study their properties. Local error estimates for these rules are derived in a general framework.

Koji Mukai

The short interval between successive outbursts of RS Oph strongly suggests that it has a high mass white dwarf accreting at a high rate. This, in turn, suggests the possibility of prominent X-ray emission from RS Oph in quiescence. However, archival quiescent X-ray observations of RS Oph show it to be a modest soft X-ray source but not a strong 2-10 keV X-r

Y. Aoki, M. C. Keiderling, H. Kojima

We describe the first observations on the time-dependent dissipation when the drive level of a torsional oscillator containing solid He-4 is abruptly changed. The relaxation of dissipation in solid He-4 shows rich dynamical behavior including exponential and logarithmic time-dependent decays, hysteresis, and memory effects.

F. S. S. Rosa, D. A. R. Dalvit, P. W. Milonni

Based on a generalization of the Lifshiftz theory we calculate Casimir forces involving magnetodielectric and possibly anisotropic metamaterials, focusing on the possibility of repulsive forces. It is found that Casimir repulsion decreases with magnetic dissipation, and even a small Drude background in metallic-based metamaterials acts to make attractive a C

Mikhail Gorchtein

I consider rare CP-violating decay modes $η(η&#39;)\toππ$ and note that an interaction that leads to such decays would necessarily induce a nucleon electric dipole moment (EDM). The experimental limits for the corresponding branching ratios are quite soft. I relate these decay branching ratios to the value of the induced nucleon EDM and translate the experim

Julien Toulouse, C. J. Umrigar

We pursue the development and application of the recently-introduced linear optimization method for determining the optimal linear and nonlinear parameters of Jastrow-Slater wave functions in a variational Monte Carlo framework. In this approach, the optimal parameters are found iteratively by diagonalizing the Hamiltonian matrix in the space spanned by the

Gabriel Cardona, Merce Llabres, Francesc Rossello, Gabriel Valiente

The presence of reticulate evolutionary events in phylogenies turn phylogenetic trees into phylogenetic networks. These events imply in particular that there may exist multiple evolutionary paths from a non-extant species to an extant one, and this multiplicity makes the comparison of phylogenetic networks much more difficult than the comparison of phylogene

Dastgeer Shaikh, P. K. Shukla

Electron plasmas confined by an external magnetic field exhibit variations in a two-dimensional plane orthogonal to the confining magnetic field. A nonlinear fluid simulation code to investigate the properties of 2-D electron plasma wave turbulence in a nonuniform magnetoplasma has been developed. It is found that the presence of the density gradient convect

Cheng Yeaw Ku, David B. Wales

We consider the Cayley graph on the symmetric group Sn generated by derangements. It is well known that the eigenvalues of this grpah are indexed by partitions of n. We investigate how these eigenvalues are determined by the shape of their corresponding partitions. In particular, we show that the sign of an eigenvalue is the parity of the number of cells bel

Ron Larham

A recent paper proposing a model of the limiting speed of the domino effect is discussed with reference to its need and the need of models in general for validation against experimental data. It is shown that the proposed model diverges significantly from experimentally derived speed estimates over a significant range of domino spacing using data from the ex

T. O. B. Schmidt, R. Neuhäuser, N. Vogt, A. Seifahrt

Neuhaeuser & Comeron (1998, 1999) presented direct imaging evidence, as well as first spectra, of several young stellar and sub-stellar M6- to M8-type objects in the Cha I dark cloud. One of these objects is Cha Halpha 2, classified as brown dwarf candidate in several publications and suggested as possible binary in Neuhaeuser et al. (2002). We have searched

Vanessa Dury, S. De Rijcke, Victor P. Debattista, H. Dejonghe

Lopsidedness is common in spiral galaxies. Often, there is no obvious external cause, such as an interaction with a nearby galaxy, for such features. Alternatively, the lopsidedness may have an internal cause, such as a dynamical instability. In order to explore this idea, we have developed a computer code that searches for self-consistent perturbations in r

F. J. Beron-Vera, M. G. Brown, M. J. Olascoaga, I. I. Rypina

The connection between transport barriers and potential vorticity (PV) barriers in PV-conserving flows is investigated with a focus on zonal jets in planetary atmospheres. A perturbed PV-staircase model is used to illustrate important concepts. This flow consists of a sequence of narrow eastward and broad westward zonal jets with a staircase PV structure; th

Paola Focardi, Valentina Zitelli, Silvia Marinoni

Galaxy pairs are ideal sites in which to investigate the role of interaction on nuclear activity. For this reason we have undertaken a spectroscopic survey of a large homogeneous sample of galaxy pairs (UZC-BGP) and we present the results of the nuclear spectral classification of 48 pairs (more than half of the whole sample). The fraction of emission line ga

K. Ueshima, K. Abe, T. Iida, M. Ikeda

The intensity of scintillation light emission from liquid xenon at room temperature was measured. The scintillation light yield at 1 deg. was measured to be 0.64 +/- 0.02 (stat.) +/- 0.06 (sys.) of that at -100 deg. Using the reported light yield at -100 deg. (46 photons/keV), the measured light yield at 1 deg. corresponds to 29 photons/keV. This result show

Hideo Mabuchi

A simple algebraic procedure is described for deriving Maxwell-Bloch-type equations from single-atom cavity quantum electrodynamics (cavity QED) master equations via orthogonal projection onto a manifold of semiclassical states. In particular the usual Maxwell-Bloch Equations are obtained--up to a state-dependent correction factor of order unity--straightfor

A. De Luca, R. P. Mignani, S. Zaggia, G. Beccari

1E 161348-5055 (1E 1613) is a point-like, soft X-ray source originally identified as a radio-quiet, isolated neutron star, shining at the center of the 2000 yr old supernova remnant RCW103. 1E 1613 features a puzzling 6.67 hour periodicity as well as a dramatic variability over a time scale of few years. Such a temporal behavior, coupled to the young age and

Caroline Thomas, Sylvain Picaud, Olivier Mousis, Vincent Ballenegger

In this paper, we use a statistical thermodynamic approach to quantify the efficiency with which clathrates on the surface of Titan trap noble gases. We consider different values of the Ar, Kr, Xe, CH4, C2H6 and N2 abundances in the gas phase that may be representative of Titan&#39;s early atmosphere. We discuss the effect of the various parameters that are

Dong Sun, Zong-Kwei Wu, Charles Divin, Xuebin Li

We investigate the ultrafast relaxation dynamics of hot Dirac fermionic quasiparticles in multilayer epitaxial graphene using ultrafast optical differential transmission spectroscopy. We observe DT spectra which are well described by interband transitions with no electron-hole interaction. Following the initial thermalization and emission of high-energy phon

B. Andrei Bernevig, F. D. M. Haldane

We compute the physical properties of non-Abelian Fractional Quantum Hall (FQH) states described by Jack polynomials at general filling $ν=\frac{k}{r}$. For $r=2$, these states are identical to the $Z_k$ Read-Rezayi parafermions, whereas for $r>2$ they represent new FQH states. The $r=k+1$ states, multiplied by a Vandermonde determinant, are a non-Abelian al

Y. -T. Cui, J. C. Sankey, C. Wang, K. V. Thadani

The torque generated by the transfer of spin angular momentum from a spin-polarized current to a nanoscale ferromagnet can switch the orientation of the nanomagnet much more efficiently than a current-generated magnetic field, and is therefore in development for use in next-generation magnetic random access memory (MRAM). Up to now, only DC currents and squa

Tor Helleseth, Henk D. L. Hollmann, Alexander Kholosha, Zeying Wang

We study ternary monomial functions of the form $f(x)=\Tr_n(ax^d)$, where $x\in \Ff_{3^n}$ and $\Tr_n: \Ff_{3^n}\to \Ff_3$ is the absolute trace function. Using a lemma of Hou \cite{hou}, Stickelberger&#39;s theorem on Gauss sums, and certain ternary weight inequalities, we show that certain ternary monomial functions arising from \cite{hk1} are weakly regul

Eric V. Linder, Georg Robbers

The presence of dark energy at high redshift influences both the cosmic sound horizon and the distance to last scattering of the cosmic microwave background. We demonstrate that through the degeneracy in their ratio, early dark energy can lie hidden in the CMB temperature and polarization spectra, leading to an unrecognized shift in the sound horizon. If the

E. Ben-Naim, P. L. Krapivsky

We investigate a reversible polymerization process in which individual polymers aggregate and fragment at a rate proportional to their molecular weight. We find a nonequilibrium phase transition despite the fact that the dynamics are perfectly reversible. When the strength of the fragmentation process exceeds a critical threshold, the system reaches a thermo

M. Sewilo, E. Churchwell, S. Kurtz, W. M. Goss

High resolution (0.15&#34;) Very Large Array observations of 7 mm continuum and H53a line emission toward the hypercompact H II region G28.20-0.04N reveal the presence of large-scale ordered motions. We find a velocity gradient of 1000 km/s/pc along the minor axis of the continuum source. Lower resolution (1.0&#34;-2.3&#34;) radio recombination line observat

K. V. Thadani, G. Finocchio, Z. -P. Li, O. Ozatay

We measure the microwave signals produced by spin-torque-driven magnetization dynamics in patterned magnetic multilayer devices at room temperature, as a function of the angle of a magnetic field applied in the sample plane. We find strong variations in the frequency linewidth of the signals, with a decrease by more than a factor of 20 as the field is rotate

Thomas Oikonomou

The present work investigates the Lesche stability (experimental robustness), the thermodynamic stability, the Legendre structure of thermodynamics, and derives the Maximum Entropy distribution of the one--parametric ``nonextensive Gaussian&#39;&#39; entropy. We show that this entropy definition fulfills both stability conditions for all values of its parame

CLEO Collaboration, K. M. Ecklund

Using a data sample of 24.5 million psi(2S) the reactions psi(2S)->gamma chi_cJ, chi_cJ->gamma gamma have been studied for the first time to determine the two-photon widths of the chi_cJ states of charmonium in their decay into two photons. The measured quantities are B(psi(2S)->gamma chi_c0)xB(chi_c0->gamma gamma)=(2.22+-0.32+-0.10)x10^-5, and B(psi(2S)->ga

Rahul Roy

It is shown that superfluids in two and three dimensions which have time reversal invariant ground states have phases which are distinguished by a topological invariant. Further, it is shown that the B-phase of $^3$ He is a superfluid in the non-trivial topological class. Superfluids in the non-trivial topological class are shown to have gapless edge states

Sergei V. Ketov, Olaf Lechtenfeld

Certain supersymmetric sigma models in 2+1 dimensions feature multi-soliton solutions, with and without scattering. We subject these systems to a non-anticommutative deformation by replacing the Grassmann algebra of the odd superspace coordinates with a Clifford algebra. Static CP^1 and scattering U(2) solitons are constructed and carry an additional spin-1/

M. M. Romanova, M. Long, A. K. Kulkarni, R. Kurosawa

We discuss a number of topics relevant to disk-magnetosphere interaction and how numerical simulations illuminate them. The topics include: (1) disk-magnetosphere interaction and the problem of disk-locking; (2) the wind problem; (3) structure of the magnetospheric flow, hot spots at the star&#39;s surface, and the inner disk region; (4) modeling of spectra

S. G. Djorgovski, M. Volonteri, V. Springel, V. Bromm

The relationship between galaxies and supermassive black holes (SMBH) found in their cores plays a key role in the formation and evolution of both of these major constituents of the universe, as well as the evolution of the intergalactic medium. Neither can be fully understood on their own, and studies of galaxy and SMBH co-formation and co-evolution are now

Rui Zhang, Toan T. Nguyen

Budding from the plasma membrane of the host cell is an indispensable step in the life cycle of the Human Immunodeficiency Virus (HIV), which belongs to a large family of enveloped RNA viruses, retroviruses. Unlike regular enveloped viruses, retrovirus budding happens {\em concurrently} with the self-assembly of retrovirus protein subunits (Gags) into spheri

Jaime Sanudo, Ricardo Lopez-Ruiz

The Fisher-Shannon information and a statistical measure of complexity are calculated in the position and momentum spaces for the wave functions of the H-atom. For each level of energy, it is found that these two indicators take their minimum values on the orbitals that correspond to the classical (circular) orbits in the Bohr atomic model, just those with t

Adriana Pálffy, Zoltán Harman, Christophor Kozhuharov, Carsten Brandau

The resonance strength of the two-step process of nuclear excitation by electron capture followed by $γ$ decay of the nucleus can be significantly increased in highly charged ions if the resonant capture proceeds via an excited electronic state with subsequent fast x-ray emission. For fully ionized $^{238}_{92}\mathrm{U}$ and $^{232}_{90}\mathrm{Th}$, the {x

J. -P. Nikkarila, M. Koskinen, S. M. Reimann, M. Manninen

We study the spectral and magnetic properties of one-dimensional lattices filled with 2 to 4 fermions (with spin 1/2) per lattice site. We use a generalized Hubbard model that takes account all interactions on a lattice site, and solve the many-particle problem by exact diagonalization. We find an intriguing magnetic phase diagram which includes ferromagneti

T. Rothenberger, S. Oez, E. Tahirovic, C. Schommer

The recognition, involvement, and description of main actors influences the story line of the whole text. This is of higher importance as the text per se represents a flow of words and expressions that once it is read it is lost. In this respect, the understanding of a text and moreover on how the actor exactly behaves is not only a major concern: as human b

E. Guadagnini

The low energy scattering of gravitons from a composite extended system, which is made of classical massive bodies, is considered; by using the Feynman rules of effective quantum gravity, the corresponding cross-section is computed to lowest order in powers of the gravitational coupling constant. For the gravitons scattering from a rotating planet or a star,

Michael J. Barber, Margarida Faria, Ludwig Streit, Oleg Strogan

Bipartite networks are a useful tool for representing and investigating interaction networks. We consider methods for identifying communities in bipartite networks. Intuitive notions of network community groups are made explicit using Newman's modularity measure. A specialized version of the modularity, adapted to be appropriate for bipartite networks, is pr

T. Proslier, J. F. Zasadzinski, L. Cooley, C. Antoine

Tunneling spectroscopy was performed on Nb pieces prepared by the same processes used to etch and clean superconducting radio frequency (SRF) cavities. Air exposed, electropolished Nb exhibited a surface superconducting gap delta=1.55 meV, characteristic of clean, bulk Nb. However the tunneling density of states (DOS) was broadened significantly. The Nb piec

Karen K. Y. Lee, Yehuda Avniel, Steven G. Johnson

We derive a sufficient condition for the existence of index-guided modes in a very general class of dielectric waveguides, including photonic-crystal fibers (arbitrary periodic claddings, such as ``holey fibers&#39;&#39;), anisotropic materials, and waveguides with periodicity along the propagation direction. This condition provides a rigorous guarantee of c

Harald Krueger, Douglas P. Hamilton, Richard Moissl, Eberhard Gruen

During its late orbital mission at Jupiter the Galileo spacecraft made two passages through the giant planet&#39;s gossamer ring system. The impact-ionization dust detector on board successfully recorded dust impacts during both ring passages and provided the first in-situ measurements from a dusty planetary ring. In all, a few thousand dust impacts were cou

Stephane Haussler, Marcus Bleicher, Horst Stoecker

Within the framework of the dynamical recombination approach implemented in the partonic/hadronic quark Molecular Dynamics (qMD) model, we investigate numerous QGP signals constructed from the correlations and fluctuations of conserved charges, namely charged particle ratio fluctuations, charge transfer fluctuations as well as various ratios of susceptibilit

Leonid I. Klushin, Alexander M. Skvortsov, Hsiao-Ping Hsu, Kurt Binder

We present a scaling theory and Monte Carlo (MC) simulation results for a flexible polymer chain slowly dragged by one end into a nanotube. We also describe the situation when the completely confined chain is released and gradually leaves the tube. MC simulations were performed for a self-avoiding lattice model with a biased chain growth algorithm, the prune

HESS Collaboration, F. Aharonian

HESS J1745-303 is an extended, unidentified VHE (very high energy) gamma-ray source discovered using HESS in the Galactic Plane Survey. Since no obvious counterpart has previously been found in longer-wavelength data, the processes that power the VHE emission are not well understood. Combining the latest VHE data with recent XMM-Newton observations and a var

Sebastian Busch, Torben Haugaard Jensen, Yuriy Chushkin, Andrei Fluerasu

X-ray photon correlation spectroscopy was used to measure the diffusive dynamics of colloidal particles in a shear flow. The results presented here show how the intensity autocorrelation functions measure both the diffusive dynamics of the particles and their flow-induced, convective motion. However, in the limit of low flow/shear rates, it is possible to ob

Noga Alon, Yossi Azar, Shai Gutner

We study the admission control problem in general networks. Communication requests arrive over time, and the online algorithm accepts or rejects each request while maintaining the capacity limitations of the network. The admission control problem has been usually analyzed as a benefit problem, where the goal is to devise an online algorithm that accepts the

Jorick S. Vink, Janet E. Drew, Danny Steeghs, Nick J. Wright

We report on the discovery of over 50 strong Halpha emitting objects towards the large OB association Cyg OB2 and the HII region DR 15 on its southern periphery. This was achieved using the INT Photometric Halpha Survey of the Northern Galactic Plane (IPHAS), combined with follow-up spectroscopy using the MMT multi-object spectrometer HectoSpec. We present o

The BABAR Collaboration, B. Aubert

We present measurements of the decays B+ -> X(3872) K+ and B0 -> X(3872) K0 with X(3872) -> Jpsi pi+ pi-. The data sample used, collected with the BABAR detector at the PEP-II e+e- asymmetric-energy storage ring, corresponds to 455 x 10^6 BBbar pairs. Branching fraction measurements of BF(B+ -> X(3872) K+) x BF(X(3872) -> Jpsi pi+ pi-) = (8.4 +/- 1.5 +/- 0.7

F. Patisson, B. Dussoubs, D. Ablitzer

One of the major issues with multiparticle reactors is to handle their multiscale aspect. For modeling, it usually comes to coupling a reactor model (describing the phenomena at the macroscopic scale) with a so-called grain model (simulating the behavior of a single grain or a particle). An interesting approach proposed by H.Y. Sohn (1978) is to use the law

Shaouly Bar-Shalom, Gad Eilam, Tao Han, Amarjit Soni

We consider a new interaction between a heavy Majorana neutrino (N) and a charged Higgs boson (H+) and show that it can have drastic implications on lepton number violating (LNV) signal of same-sign dileptons at the LHC. The LNV signal of heavy Majorana neutrinos previously considered at the LHC, pp -> l+ N -> l+ l+ W-, may be overwhelmed by pp -> l+ N -> l+

Omer Egecioglu

We show that the determinant of a Hankel matrix of odd dimension n whose entries are the enumerators of the Jacobi symbols which depend on the row and the column indices vanishes iff n is composite. If the dimension is a prime p, then the determinant evaluates to a polynomial of degree p-1 which is the product of a power of p and the generating polynomial of

Nicholas W. Watkins, Daniel Credgington, Raul Sanchez, Sandra C. Chapman

Levy flights and fractional Brownian motion (fBm) have become exemplars of the heavy tailed jumps and long-ranged memory seen in space physics and elsewhere. Natural time series frequently combine both effects, and Linear Fractional Stable Motion (LFSM) is a model process of this type, combining alpha-stable jumps with a memory kernel. In contrast complex ph

M. T. Glossop, N. Khoshkhou, K. Ingersent

We report nonperturbative results for the interacting quantum-critical behavior in a Bose-Fermi Kondo model describing a spin-1/2 coupled both to a fermionic band with a pseudogap density of states and to a dissipative bosonic bath. The model serves as a paradigm for studying the interplay between Kondo physics and low-energy dissipative modes in strongly co

D. Wagner, O. Devisme, F. Patisson, D. Ablitzer

To reduce the emission of greenhouse gases by the steel industry, particularly for ironmaking, the production of DRI (Direct Reduced Iron) using hydrogen as the reducing gas instead of carbon monoxide is being considered. In this context, the reduction of pure hematite by hydrogen was studied at the laboratory scale, varying the experimental conditions and o

Yinfang Shen, Weian Zheng

We transfer the celebrating Monge-Kontorovich problem in a bounded domain of Euclidean plane into a Dirichlet boundary problem associated to a quasi-linear elliptic equation with $0-$order term missing in its diffusion coefficients: \begin{eqnarray*} A(x, F&#39;_x)F&#39;&#39;_{xx}+B(y, F&#39;_y)F&#39;&#39;_{yy}&=&C(x, y, F&#39;_x, F&#39;_y) \end{eqnarray*} w

Alain Aspect, Denis Boiron, Christoph Westbrook

Atom optics, a field which takes much inspiration from traditional optics, has advanced to the point that some of the fundamental experiments of quantum optics, involving photon correlations, have found atomic analogs. We discuss some recent experiments on atom bunching and anti-bunching as well as some prospects for extending them to the field of many body

Mari Kobayashi, Xavier Mestre

We consider a two-hop wireless network where a transmitter communicates with a receiver via $M$ relays with an amplify-and-forward (AF) protocol. Recent works have shown that sophisticated linear processing such as beamforming and distributed space-time coding (DSTC) at relays enables to improve the AF performance. However, the relative utility of these stra

P. Zasche, A. Liakos, M. Wolf, P. Niarchos

Six semi-detached Algol-type binaries lacking a period analysis were chosen to test for a presence of a third body. The O-C diagrams of these binaries were analyzed with the least-squares method by using all available times of minima. Also fourteen new minima, obtained from our observations, were included in the present research. The light-time effect was ad

Yang Sun, Gui-Lu Long, Falih Al-Khudair, Javid A. Sheikh

Recent experimental advances have made it possible to study excited structure in superheavy nuclei. The observed states have often been interpreted as quasi-particle excitations. We show that in superheavy nuclei collective vibrations systematically appear as low-energy excitation modes. By using the microscopic Triaxial Projected Shell Model, we make a deta

Timothy J. Hollowood, S. Prem Kumar, Asad Naqvi, Philip Wild

We study the N = 4 theory at weak coupling, on a three sphere in the grand canonical ensemble with R symmetry chemical potentials. We focus attention on near critical values for the chemical potentials, above which the classical theory has no ground state. By computing a one loop effective potential for the light degrees of freedom in this regime, we show th

C. J. Evans, I. Hunter, S. J. Smartt, D. J. Lennon

The VLT-FLAMES Survey of Massive Stars was an ESO Large Programme to understand rotational mixing and stellar mass-loss in different metallicity environments, in order to better constrain massive star evolution. We gathered high-quality spectra of over 800 stars in the Galaxy and in the Magellanic Clouds. A sample of this size is unprecedented, enabled by th

Yoh Takei, Eric D. Miller, Joel N. Bregman, Shunsuke Kimura

About half of the baryons in the local Universe are thought to reside in the so-called warm-hot intergalactic medium (WHIM) at temperatures of 0.1-10 million K. Thermal soft excess emission in the spectrum of some cluster outskirts that contains OVII and/or OVIII emission lines is regarded as evidence of the WHIM, although the origin of the lines is controve

N. M. R. Peres, T. Stauber, A. H. Castro Neto

We study the infrared conductivity of graphene at finite chemical potential and temperature taking into account the effect of phonons and disorder due to charged impurities and unitary scatterers. The screening of the long-range Coulomb potential is treated using the random phase approximation coupled to the coherent potential approximation. The effect of th

Haruhiko Kuroe, Kouhei Kusakabe, Akira Oosawa, Tomoyuki Sekine

We report the observation of the $A_{\rm g}$-symmetric one-magnon Raman peak in the magnon Bose-Einstein condensation phase of TlCuCl$_{3}$. Its Raman shift traces the one-magnon energy at the magnetic $Γ$ point, and its intensity is proportional to the squared transverse magnetization. The appearance of the one-magnon Raman scattering originates from the ex

Stavros Komineas, Nikos Papanicolaou

We show that transmutation of linear momentum into position may occur in a system of three magnetic vortices thanks to a direct link between topology and dynamics in a ferromagnet. This happens via exchange between the linear momentum of a vortex-antivortex pair and the position of a single vortex during a semi-elastic scattering process. Vortex polarity swi

Arzu Boysal, Michele Vergne

We give an elementary algebraic proof of Paradan&#39;s wall crossing formulae for partition functions. We also express such jumps in volume and partition functions by one dimensional residue formulae. Subsequently we reprove the relation between them as given by the application of a generalized Khovanskii-Pukhlikov differential operator.

Peter Talkner, P. Sekhar Burada, Peter Hänggi

Various aspects of the statistics of work performed by an external classical force on a quantum mechanical system are elucidated for a driven harmonic oscillator. In this special case two parameters are introduced that are sufficient to completely characterize the force protocol. Explicit results for the characteristic function of work and the respective pro

Valentino Lacquaniti, Giovanni Montani

We analyze some unphysical features of the geodesic approach to matter coupling in a compactified Kaluza-Klein scenario, like the q/m puzzle and the huge massive modes. We propose a new approach, based on Papapetrou multipole expansion, that provides a new equation for the motion of a test particle. We show how this equation provides right couplings and does

Evgeny Korotyaev, Anton Kutsenko

We consider the Schrödinger operator on nanoribbons (tight-binding models) in an external electric potentials $V$. The corresponding electric field is perpendicular to the axis of the nanoribbon. If V=0, then the spectrum of the Schrödinger operator consists of two spectral bands and the flat band (i.e., the eigenvalue with infinite multiplicity) between the

Ludwig Geske, I. B. Misirlioglu, Ionela Vrejoiu, Marin Alexe

Heterostructures consisting of PbZr0.2Ti0.8O3 and PbZr0.4Ti0.6O3 films grown on a SrTiO3 (100) substrate with a SrRuO3 bottom electrode were prepared by pulsed laser deposition. Using the additional interface provided by the ferroelectric bilayer structure and changing the sequence of the layers, the dislocation content and domain patterns were varied. The r

Eduardo H. M. Brietzke

We consider an identity relating Fibonacci numbers to Pascal&#39;s triangle discovered by G. E. Andrews. Several authors provided proofs of this identity, most of them rather involved or else relying on sophisticated number theoretical arguments. We present a new proof, quite simple and based on a Riordan array argument. The main point of the proof is the co

Eleni Vardoulaki, Steve Rawlings, Chris Simpson, David G. Bonfield

We study the 37 brightest radio sources in the Subaru/XMM-Newton Deep Field (SXDF). We have spectroscopic redshifts for 24 of 37 objects and photometric redshifts for the remainder, yielding a median redshift z_med for the whole sample of z_med ~= 1.1 and a median radio luminosity close to the `FRI/FRII&#39; luminosity divide. Using mid-IR (Spitzer MIPS 24 u

J. Benhelm, G. Kirchmair, C. F. Roos, R. Blatt

Today ion traps are among the most promising physical systems for constructing a quantum device harnessing the computing power inherent in the laws of quantum physics. The standard circuit model of quantum computing requires a universal set of quantum logic gates for the implementation of arbitrary quantum operations. As in classical models of computation, q

Jens Jonasson

Linear first order systems of partial differential equations of the form $\nabla f = M\nabla g,$ where $M$ is a constant matrix, are studied on vector spaces over the fields of real and complex numbers, respectively. The Cauchy--Riemann equations belong to this class. We introduce a bilinear $*$-multiplication on the solution space, which plays the role of a

J. B. Conrey, N. C. Snaith

We present a new approach to obtaining the lower order terms for $n$-correlation of the zeros of the Riemann zeta function. Our approach is based on the `ratios conjecture&#39; of Conrey, Farmer, and Zirnbauer. Assuming the ratios conjecture we prove a formula which explicitly gives all of the lower order terms in any order correlation. Our method works equa

L. Tiemann, W. Dietsche, M. Hauser, K. von Klitzing

We have investigated the tunneling properties of an electron double quantum well system where the lowest Landau level of each quantum well is half filled. This system is expected to be a Bose condensate of excitons. Our four-terminal dc measurements reveal a nearly vanishing interlayer voltage and the existence of critical tunneling currents which depend on

Y. Hikita, L. Fitting Kourkoutis, T. Susaki, D. A. Muller

We observed a strong modulation in the current-voltage characteristics of SrRuO$_3$/Nb:SrTiO$_3$ Schottky junctions by Mn substitution in SrRuO$_3$, which induces a metal-insulator transition in bulk. The temperature dependence of the junction ideality factor indicates an increased spatial inhomogeneity of the interface potential with substitution. Furthermo

A. Gusdorf, S. Cabrit, D. R. Flower, G. Pineau des Forets

We study the production of SiO in the gas phase of molecular outflows, through the sputtering of Si--bearing material in refractory grain cores, which are taken to be olivine; we calculate also the rotational line spectrum of the SiO. The sputtering is driven by neutral particle impact on charged grains, in steady--state C-type shock waves, at the speed of a

Gaspar Galaz, Paulo Cortes, Leonardo Bronfman, Monica Rubio

Using the APEX sub-millimeter telescope we have investigated the 12CO(3-2) emission in five face-on nearby barred spiral galaxies, where three of them are high surface brightness galaxies (HSBs) lying at the Freeman limit, and two are low surface brightness galaxies (LSBs). We have positive detections for two of three HSB spirals and non-detections for the L

Neri Merhav

We demonstrate that there is an intimate relationship between the magnetic properties of Derrida&#39;s random energy model (REM) of spin glasses and the problem of joint source--channel coding in Information Theory. In particular, typical patterns of erroneously decoded messages in the coding problem have ``magnetization&#39;&#39; properties that are analogo

Claudiu Genes, David Vitali, Paolo Tombesi

Laser cooling of a mechanical mode of a resonator by the radiation pressure of a detuned optical cavity mode has been recently demonstrated by various groups in different experimental configurations. Here we consider the effect of a second mechanical mode with a close, but different resonance frequency. We show that the nearby mechanical resonance is simulta

Tomoaki Hamasaki, Tomoyuki Ide, Haruhiko Kuroe, Tomoyuki Sekine

Investigation of the magnetism of Cu$_3$Mo$_2$O$_9$ single crystal, which has antiferromagnetic (AF) linear chains interacting with AF dimers, reveals an AF second-order phase transition at $T_{\rm N} = 7.9$ K. Although weak ferromagnetic-like behavior appears at lower temperatures in low magnetic fields, complete remanent magnetization cannot be detected do

J. Bellazzini, C. Bonanno, G. Siciliano

We study the existence of vortices of the Klein-Gordon-Maxwell equations in the two dimensional case. In particular we find sufficient conditions for the existence of vortices in the magneto-static case, i.e when the electric potential $ϕ=0$. This result, due to the lack of suitable embedding theorems for the vector potential $\A$ is achieved with the help o

S. Dumitru, A. Boer

Both classical and respectively quantum observables can be modeled as somewhat similar examples of random variables. In such a model the associated measurements preserve the values spectrum of an observable but change the corresponding probabilistic weights (probability density or respectively the wave function). Such a model ensures theoretical estimations