June 2007 arXiv papers — page 45

S. W. Allen, D. A. Rapetti, R. W. Schmidt, H. Ebeling

We present constraints on the mean matter density, Omega_m, dark energy density, Omega_de, and the dark energy equation of state parameter, w, using Chandra measurements of the X-ray gas mass fraction (fgas) in 42 hot (kT>5keV), X-ray luminous, dynamically relaxed galaxy clusters spanning the redshift range 0.05<z<1.1. Using only the fgas data for the 6 lowe

Peter Mathe, Erich Novak

We study the integration of functions with respect to an unknown density. We compare the simple Monte Carlo method (which is almost optimal for a certain large class of inputs) and compare it with the Metropolis algorithm (based on a suitable ball walk). Using MCMC we prove (for certain classes of inputs) that adaptive methods are much better than nonadaptiv

T. A. Maier, A. Macridin, M. Jarrell, D. J. Scalapino

A dynamic cluster quantum Monte Carlo algorithm is used to study a spin susceptibility representation of the pairing interaction for the two-dimensional Hubbard model with an on-site Coulomb interaction equal to the bandwidth for various doping levels. We find that the pairing interaction is well approximated by ${3/2}\Ub(T)^2χ(K-K&#39;)$ with an effective t

Daniele Colosi

We study the quantum theory of a simple general relativistic quantum model of two coupled harmonic oscillators and compute the two-point function following a proposal first introduced in the context of loop quantum gravity.

Rita K. Mann, David Jewitt, Pedro Lacerda

We present the results of an optical lightcurve survey of 114 Jovian Trojan asteroids conducted to determine the fraction of contact binaries. Sparse-sampling was used to assess the photometric range of the asteroids and those showing the largest ranges were targeted for detailed follow-up observations. This survey led to the discovery of two Trojan asteroid

Stefano De Leo, Pietro Rotelli

We investigate the tunnelling zone V0 < E < V0+m for a one-dimensional potential within the Dirac equation. We find the appearance of superluminal transit times akin to the Hartman effect.

Stefano De Leo, Gisele C. Ducati

We compare the behavior of a wave packet in the presence of a complex and a pure quaternionic potential step. This analysis, done for a gaussian convolution function, sheds new light on the possibility to recognize quaternionic deviations from standard quantum mechanics.

Qiang Li, C. N. Georghiades

In this paper, we study the end-to-end distortion/delay tradeoff for a analogue source transmitted over a fading channel. The analogue source is quantized and stored in a buffer until it is transmitted. There are two extreme cases as far as buffer delay is concerned: no delay and infinite delay. We observe that there is a significant power gain by introducin

Yuval Peres, Wilhelm Schlag

Let ${n_k}$ be an increasing lacunary sequence, i.e., $n_{k+1}/n_k>1+r$ for some $r>0$. In 1987, P. Erdos asked for the chromatic number of a graph $G$ on the integers, where two integers $a,b$ are connected by an edge iff their difference $|a-b|$ is in the sequence ${n_k}$. Y. Katznelson found a connection to a Diophantine approximation problem (also due to

R. Campoamor-Stursberg

The problem of non-solvable contractions of Lie algebras is analyzed. By means of a stability theorem, the problem is shown to be deeply related to the embeddings among semisimple Lie algebras and the resulting branching rules for representations. With this procedure, we determine all deformations of indecomposable Lie algebras having a nontrivial Levi decom

T. A. Porter, W. B. Atwood, B. Baughman, R. P. Johnson

The diffuse extragalactic gamma-ray background (EGRB) has been derived by various groups from observations by the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Gamma Ray Observatory (CGRO). The derived EGRB consists of gamma rays that may come from astrophysical components, such as from unresolved extragalactic point sources (bla

Stephen R. Sharpe

I discuss the constraints on the lattice spacing, a, the quark masses, m, the box size, L, and particularly the residual mass, m_res, such that one can successfully calculate phenomenologically interesting quantities using Domain Wall fermions (DWF). The constraints on a, m, and L are largely common with other improved fermion discretizations, and I emphasiz

S. Raby, A. Wingerter

We investigate whether the hypercharge assignments in the Standard Model can be interpreted as a hint at Grand Unification in the context of heterotic string theory. To this end, we introduce a general method to calculate U(1)_Y for any heterotic orbifold and compare our findings to the cases where hypercharge arises from a GUT. Surprisingly, in the overwhel

Kenjiro K. Gomes, Abhay N. Pasupathy, Aakash Pushp, Shimpei Ono

Pairing of electrons in conventional superconductors occurs at the superconducting transition temperature Tc, creating an energy gap D in the electronic density of states (DOS). In the high-Tc superconductors, a partial gap in the DOS exists for a range of temperatures above Tc. A key question is whether the gap in the DOS above Tc is associated with pairing

Carl M. Bender, Philip D. Mannheim

Contrary to common belief, it is shown that theories whose field equations are higher than second order in derivatives need not be stricken with ghosts. In particular, the prototypical fourth-order derivative Pais-Uhlenbeck oscillator model is shown to be free of states of negative energy or negative norm. When correctly formulated (as a $\cP\cT$ symmetric t

Jean-François Delmas, Jean-Stéphane Dhersin, Arno Siri-Jegousse

We give the asymptotic distribution of the length of partial coalescent trees for Beta and related coalescents. This allows us to give the asymptotic distribution of the number of (neutral) mutations in the partial tree. This is a first step to study the asymptotic distribution of a natural estimator of DNA mutation rate for species with large families.

Leandro Aolita, Luiz Davidovich, Kihwan Kim, Hartmut Häffner

We consider interactions that generate a universal set of quantum gates on logical qubits encoded in a collective-dephasing-free subspace, and discuss their implementations with trapped ions. This allows for the removal of the by-far largest source of decoherence in current trapped-ion experiments, collective dephasing. In addition, an explicit parametrizati

Denis Feyel, Arnaud De La Pradelle, Gabriel Mokobodzki

In a preceding paper [E.J.ofProb.34,860-892,(2006)], we proved a sewing lemma which was a key result for the study of Holder continuous functions. In this paper we give a non-commutative version of this lemma with some applications.

Greg Piepmeyer, Mark E. Walker

In 1987 Roberts completed the proof of the New Intersection Theorem (NIT) by settling the mixed characteristic case using local Chern characters, as developed by Fulton and also by Roberts. His proof has been the only one recorded of the NIT in mixed characteristic. This paper gives a new proof of this theorem, one which mostly parallels Roberts&#39; origina

Gregory B. Cook, Bernard F. Whiting

We present a new method for computing the best approximation to a Killing vector on closed 2-surfaces that are topologically S^2. When solutions of Killing&#39;s equation do not exist, this method is shown to yield results superior to those produced by existing methods. In addition, this method appears to provide a new tool for studying the horizon geometry

Na Sai, Michael Zwolak, Giovanni Vignale, Massimiliano Di Ventra

We reply to the comment by Jung, Bokes, and Godby (arXiv:0706.0140) on our paper Phys. Rev. Lett. 94, 186810 (2005). We show that the results in their comment should not be taken as an indication that the viscosity corrections to the conductance of real nanoscale structures are small. A more accurate treatment of the density and current density distribution

Arne Schafer, Tim Salditt, Maikel C. Rheinstadter

We report an Atomic Force Microscopy (AFM) study on thick multi lamellar stacks of approx. 10 mum thickness (about 1500 stacked membranes) of DMPC (1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine) deposited on silicon wafers. These thick stacks could be stabilized for measurements under excess water or solution. From force curves we determine the compression

Erkko Lehtonen, Agnes Szendrei

For each clone C on a set A there is an associated equivalence relation, called C-equivalence, on the set of all operations on A, which relates two operations iff each one is a substitution instance of the other using operations from C. In this paper we prove that if C is a discriminator clone on a finite set, then there are only finitely many C-equivalence

Long J. Lu, Andrea Sboner, Yuanpeng J. Huang, Hao Xin Lu

Pathways are integral to systems biology. Their classical representation has proven useful but is inconsistent in the meaning assigned to each arrow (or edge) and inadvertently implies the isolation of one pathway from another. Conversely, modern high-throughput experiments give rise to standardized networks facilitating topological calculations. Combining t

Joachim Moortgat, Eric G. Blackman, Chuang Ren, Xianglong Kong

We present preliminary results of particle-in-cell simulations of collisionless magnetic reconnection for conditions that apply to magnetically dominated pair plasma jets such as those in gamma-ray bursts. We find similar behaviour to previous authors but with reduced reconnection efficiency. This results because we include the full electromagnetic field dyn

N. V. Krylov

We discuss the possibility to represent smooth nonnegative matrix-valued functions as finite linear combinations of fixed matrices with positive real-valued coefficients whose square roots are Lipschitz continuous. This issue is reduced to a similar problem for smooth functions with values in a polyhedron.

Zhongzu Wu, D. R. Jiang, Minfeng Gu, Yi Liu

We present EVN observations of seven BL Lac objects selected from the RGB sample. To investigate the intrinsic radiation property of BL Lac objects, we estimated the Doppler factor with the VLA or MERLIN core and the total 408 MHz luminosity for a sample of 170 BL Lac objects. The intrinsic (comoving) synchrotron peak frequency was then calculated by using t

Laura Lopez Honorez

The Inert Doublet Model is an extension of the Standard Model including one extra ``Inert scalar doublet&#39;&#39; and an exact $Z_2$ symmetry. The ``Inert scalar&#39;&#39; provides a new candidate for dark matter. We present a systematic analysis of the dark matter abundance assuming the standard freeze-out mechanism and investigate the potentialities for d

Xianghong Qi, John J. Portman

A coarse-grained variational model is used to investigate the polymer dynamics of barrier crossing for a diverse set of two-state folding proteins. The model gives reliable folding rate predictions provided excluded volume terms that induce minor structural cooperativity are included in the interaction potential. In general, the cooperative folding routes ha

Javier D. Fuhr, Blas Alascio, Michel Avignon

The recent observation of a insulator to metal transition (IMT) [I. Loa et al, PRL 87, 125501 (2001)] in pure LaMnO$_3$ at 32 GPa and room temperature, well above the Neel temperature (145 K) and below the Jahn-Teller transition temperature (780 K), opens the way to a study of the role of the orbital degrees of freedom on the electronic structure in a stoich

Jana Maříková

Let R be a sufficiently saturated o-minimal expansion of a real closed field, let O be the convex hull of the rationals in R, and let st: O^n \to \mathbb{R}^n be the standard part map. For X \subseteq R^n define st(X):=st(X \cap O^n). We let \mathbb{R}_{\ind} be the structure with underlying set \mathbb{R} and expanded by all sets of the form st(X), where X

Jose R. Salgueiro, Yuri S. Kivshar

We suggest an annular waveguide coupler for switching the angular momentum of light. We study linear and nonlinear coupling of both power and momentum of an optical vortex beam launched into one of the ring cores, and demonstrate that the switching takes place well below the collapse threshold. The switching is more effective for the inner-ring excitation si

Andrew N. Jordan, Bjoern Trauzettel, Guido Burkard

The theory of weak quantum measurements is developed for quantum dot spin qubits. Building on recent experiments, we propose a control cycle to prepare, manipulate, weakly measure, and perform quantum state tomography. This is accomplished using a combination of the physics of electron spin resonance, spin blockade, and Coulomb blockade, resulting in a charg

Carlos E. Yaguna

By numerically solving the appropriate Boltzmann equations, we study the production of sterile neutrinos in models with low reheating temperatures. We take into account the production in oscillations as well as in direct decays and compute the sterile neutrino primordial spectrum, the effective number of neutrino species, and the sterile neutrino contributio

H. Paredes Gutíerrez, S. T. Pérez-Merchancano, G. E. Marques

Theoretical research on electronic properties in mesoscopic condensed matter systems has focused primarily on the electron charge freedom degrees, while its corresponding spin freedom degrees have not yet received the same attention. Nevertheless nowadays there has been an increment in the number of electron spin-related experiments showing unique possibilit

Pascal Hébrard, Emmanuel Humbert

The energy in a square membrane $Ω$ subject to constant viscous damping on a subset $ω\subset Ω$ decays exponentially in time as soon as $ω$ satisfies a geometrical condition known as the &#34;Bardos-Lebeau-Rauch&#34; condition. The rate $τ(ω)$ of this decay satisfies $τ(ω)= 2 \min(-μ(ω), g(ω))$ (see Lebeau [Math. Phys. Stud. 19 (1996) 73-109]). Here $μ(ω)$

Danielle Rousse

The persistent pods of the tree, Acacia caven, that do not fall from the tree provide opportunities for the appearance of a diverse group of insects the following season. Such pods collected during the spring of 1999 in Chile were indehiscent with highly sclerified pod walls. In contrast, persistent pods collected in Uruguay after a wet winter and spring (20

Tullio Scopigno, Spyros Yannopoulos, Filippo Scarponi, Kostas Andrikopoulos

Developing a novel experimental technique, we applied photon correlation spectroscopy using infrared radiation in liquid Sulphur around $T_λ$, i.e. in the temperature range where an abrupt increase in viscosity by four orders of magnitude is observed upon heating within few degrees. This allowed us - overcoming photo-induced and absorption effects at visible

Michele Tumminello, Fabrizio Lillo, Rosario Nunzio Mantegna

We show that the Kullback-Leibler distance is a good measure of the statistical uncertainty of correlation matrices estimated by using a finite set of data. For correlation matrices of multivariate Gaussian variables we analytically determine the expected values of the Kullback-Leibler distance of a sample correlation matrix from a reference model and we sho

Emmanuel Humbert

We give geometrical conditions under which there exist extremal functions for the sharp $L^2$-Nash inequality.

Walid Hachem, Philippe Loubaton, Jamal Najim

Consider a $N\times n$ random matrix $Y_n=(Y_{ij}^{n})$ where the entries are given by $$ Y_{ij}^{n}=\frac{σ_{ij}(n)}{\sqrt{n}} X_{ij}^{n} $$ the $X_{ij}^{n}$ being centered, independent and identically distributed random variables with unit variance and $(σ_{ij}(n); 1\le i\le N, 1\le j\le n)$ being an array of numbers we shall refer to as a variance profile

Isabel Perez-Arjona, Victor J. Sanchez-Morcillo, Eugenio Roldan

We show theoretically that a broad area bidirectional laser with slightly different cavity losses for the two counterpropagating fields sustains cavity solitons (CSs). These structures are complementary, i.e., there is a bright (dark) CS in the field with more (less) losses. Interestingly, the CSs can be written/erased by injecting suitable pulses in any of

Xiao-Ming Wang, Bang-Rong Zhou

A general research on chiral symmetry restoring phase transitions at zero temperature and finite chemical potentials under electrical neutrality condition has been conducted in a Nambu-Jona-Lasinio model to describe two-flavor normal quark matter. Depending on that $m_0/Λ$, the ratio of dynamical quark mass in vacuum and the 3D momentum cutoff in the loop in

A. S. Alexandrov, V. V. Kabanov

Chemical potential oscillations mix individual-band frequencies of the de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) magneto-oscillations in canonical low-dimensional multi-band Fermi liquids. We predict a similar mixing in canonical single-band Fermi liquids, which Fermi-surfaces have two or more extremal cross-sections. Combination harmonics are an

Wolfgang Dür, Michael J. Bremner, Hans J. Briegel

We consider the simulation of interacting high-dimensional systems using pairwise interacting qubits. The main tool in this context is the generation of effective many-body interactions, and we examine a number of different protocols for obtaining them. These methods include the usage of higher-order processes (commutator method), unitary conjugation or grap

C. Vignat, A. Plastino

We show that there exists a very natural, superstatistics-linked extension of the central limit theorem (CLT) to deformed exponentials (also called q-Gaussians): This generalization favorably compares with the one provided by S. Umarov and C. Tsallis [arXiv:cond-mat/0703533], since the latter requires a special &#34;q-independence&#34; condition on the data.

Stefano Pigola, Marco Rigoli, Alberto G. Setti

We study the steady state solutions of a generalized logistic type equation on a complete Riemannian manifold. We provide sufficient conditions for existence, respectively non-existence of positive solutions, which depend on the relative size of the coefficients and their mutual interaction with the geometry of the manifold, which is mostly taken into accoun

Dharam Vir Lal, Satoki Matsushita, Jeremy Lim

For the submillimeter band observations, we have been routinely adopting the calibration cycle time of 20-30 minutes, which is the same as any typical centimeter and millimeter band observations. This cycle time, largely corrects only the instrumental phase fluctuations and there exists residual phase fluctuations, which are attributed to temporal and spatia

Dharam Vir Lal, Luis C. Ho

Quasars (of type I) are the luminous analogs of type I Seyfert galaxies. Within the framework of unified models of active galaxies, the population of quasars of type II recently discovered with the Sloan Digital Sky Survey are the luminous analogs of type II Seyfert galaxies. Since our knowledge and understanding of the radio properties of these type II quas

E. Brion, A. S. Mouritzen, K. Molmer

We suggest a novel way to use strong Rydberg dipole-dipole interactions in order to induce non-trivial conditional dynamics in individual-atom systems and mesoscopic ensembles. Contrary to previous works, we suggest to excite atoms into different Rydberg states, which results in a potentially richer dynamical behaviour. Specifically, we investigate systems o

Christian Daveau, Abdessatar Khelifi

We consider for the time-dependent Maxwell&#39;s equations the inverse problem of identifying locations and certain properties of small electromagnetic inhomogeneities in a homogeneous background medium from dynamic measurements of the tangential component of the magnetic field on the boundary (or a part of the boundary) of a domain.

N. Furutachi, M. kimura, A. Doté, Y. Kanada-En&#39;yo

Cluster structure of 16O,18O and 20O is investigated by the antisymmettrized molecular dynamics (AMD) plus generator coordinate method (GCM). We have found the K^π=0$_2^+$ and 0$_1^-$ rotational bands of 18O that have the prominent 14C+αcluster structure. Clustering systematics becomes richer in 20O. We suggest the K^π=0$_2^+$ band that is the mixture of the

N. P. Armitage, R. Crane, G. Sambandamurthy, A. Johansson

We review our recent measurements of the complex AC conductivity of thin InO_x films studied as a function of magnetic field through the nominal 2D superconductor-insulator transition. These measurements - the first of their type to probe nonzero frequency - reveals a significant finite frequency superfluid stiffness well into the insulating regime. Unlike c

H. Arp, D. Carosati

A quasar search in the region of the active galaxy NGC 1097 yielded 31 quasars in 1984. After completion of the 2dF survey in 2004 the number of catalogued quasars just within 1 degree of the galaxy increased to 142. About 38 $\pm$ 10 of these are in excess of average background values. The evidence in 1984 is confirmed here by an increasing density of quasa

S. Liberati

The search for a quantum theory of gravity has been one of the main aims of theoretical physics for many years by now. However the efforts in this direction have been often hampered by the lack of experimental/observational tests able to select among, or at least constrain, the numerous quantum gravity models proposed so far. This situation has changed in th

Christopher J Greenshields, Jason M Reese

Howard Brenner has recently proposed modifications to the Navier-Stokes equations that relate to a diffusion of fluid volume that would be significant for flows with high density gradients. In a previous paper (Greenshields & Reese, 2007), we found these modifications gave good predictions of the viscous structure of shock waves in argon in the range Mach 1.

J. Jung, P. Bokes, R. W. Godby

In a recent paper Sai {\it et al.} [1] identified a correction $R^{dyn}$ to the DC conductance of nanoscale junctions arising from dynamical exchange-correlation ($XC$) effects within time-dependent density functional theory. This quantity contributes to the total resistance through $R=R_{s}+R^{dyn}$ where $R_{s}$ is the resistance evaluated in the absence o

Daniel Schaerer

1) Introduction 2) PopIII stars and galaxies: a &#34;top-down&#34; theoretical approach 3) Lyman-alpha physics and astrophysics 4) Distant/primeval galaxies: observations and main results

David Sauzin

The present text is an introduction to Écalle&#39;s theory of resurgent functions and alien calculus, in connection with problems of exponentially small separatrix splitting. An outline of the resurgent treatment of Abel&#39;s equation for resonant dynamics in one complex variable is included. The emphasis is on examples of nonlinear difference equations, as

N. Garcia

We present a theory presenting new quantum oscillations in the magnetoresistance that are revealed as fine structures superimposed to the Schubnikov-de-Haas oscillations. They may be observed in experiments on graphene layers as fine structures that until now seem to have been overseen or considered to be noise. These oscillations appear also in the behaviou

P. O. Petrucci, G. Ponti, G. Matt, A. L. Longinotti

Mkr 841 is a bright Seyfert 1 galaxy known to harbor a strong soft excess and a variable K$α$ iron line. It has been observed during 3 different periods by XMM for a total cumulated exposure time of $\sim$108 ks. We present in this paper a broad band spectral analysis of the complete EPIC-pn data sets. We were able to test two different models for the soft e

B Collaboration

A detailed description of an original method used to measure the luminosity accumulated by the HERA-B experiment for a data sample taken during the 2002-2003 HERA running period is reported. We show that, with this method, a total luminosity measurement can be achieved with a typical precision, including overall systematic uncertainties, at a level of 5% or

Christian Fuchs

The quest for the nuclear equation of state (EoS) at high densities and/or extreme isospin is one of the longstanding problems of nuclear physics. Ab initio calculations for the nuclear many-body problem make predictions for the density and isospin dependence of the EoS far away from the saturation point of nuclear matter. On the other hand, in recent years

S. Ihnatsenka, I. V. Zozoulenko

We perform self-consistent quantum transport calculations in open quantum dots taking into account the effect of electron interaction. We demonstrative that in the regime of the ultralow temperatures $2πk_BT\lesssimΔ$ ($Δ$ being the mean level spacing), the electron interaction strongly affects the conductance oscillations and their statistics leading to a d

Piero Madau

These lectures summarize our basic understanding of the emergence of cosmic structures, the epoch of first light, the survival of early substructure in present-day galaxy halos.

Marc Perret

We establish some upper and lower bounds for the number of rational points of Prym varieties over finite fields.

Kurt Girstmair, Gerhard Kirchner

In his treatise on floating bodies Archimedes determines the equilibrium positions of a floating paraboloid segment, but only in the case when the basis of the segment is either completely outside of the fluid or completely submerged. Here we give a mathematical model for the remaining case, i.e., two simple conditions which describe the equilibria in closed

D. Fusco, B. Bassetti, P. Jona, M. Cosentino Lagomarsino

Transcription networks, and other directed networks can be characterized by some topological observables such as for example subgraph occurrence (network motifs). In order to perform such kind of analysis, it is necessary to be able to generate suitable randomized network ensembles. Typically, one considers null networks with the same degree sequences of the

Toby Johnson

It is common to use reciprocal best hits, also known as a boomerang criterion, for determining orthology between sequences. The best hits may be found by blast, or by other more recently developed algorithms. Previous work seems to have assumed that reciprocal best hits is a sufficient but not necessary condition for orthology. In this article, I explain why

Anirban Banerjee, Jürgen Jost

We present the spectrum of the (normalized) graph Laplacian as a systematic tool for the investigation of networks, and we describe basic properties of eigenvalues and eigenfunctions. Processes of graph formation like motif joining or duplication leave characteristic traces in the spectrum. This can suggest hypotheses about the evolution of a graph represent

Takeshi Waki, Koichi Arai, Masashi Takigawa, Yuta Saiga

We report results of 11B NMR and susceptibility measurements on the quasi 2D frustrated dimer spin system SrCu2(BO3)2 under high pressure. At 2.4 GPa and in a magnetic field of 7 T, NMR lines split with decreasing temperature in two steps. A gradual splitting below T=30 K breaking the four-fold symmetry of magnetic response is followed by a further sudden sp

Francois Couchot

Let $R$ be a valuation ring and let $Q$ be its total quotient ring. It is proved that any singly projective (respectively flat) module is finitely projective if and only if $Q$ is maximal (respectively artinian). It is shown that each singly projective module is a content module if and only if any non-unit of $R$ is a zero-divisor and that each singly projec

M. Elsen, H. Jaffres, R. Mattana, L. Thevenard

We present magnetic and tunnel transport properties of (Ga,Mn)As/(In,Ga)As/(Ga,Mn)As structure before and after adequate annealing procedure. The conjugate increase of magnetization and tunnel magnetoresistance obtained after annealing is shown to be associated to the increase of both exchange energy $Δ$$_{exch}$ and hole concentration by reduction of the Mn

M. Fairbairn, S. N. Gninenko, N. V. Krasnikov, V. A. Matveev

Astrophysical sources of energetic gamma rays provide the right conditions for maximal mixing between (pseudo)scalar (axion-like) particles and photons if their coupling is as strong as suggested by the PVLAS claim. This is independent of whether or not the axion interaction is standard at all energies or becomes supressed in the extreme conditions of the st

David Sanchez, Llorens Serra, Mahn-Soo Choi

We investigate the transport properties of ballistic quantum wires in the presence of Zeeman spin splittings and a spatially inhomogeneous Rashba interaction. The Zeeman interaction is extended along the wire and produces gaps in the energy spectrum which allow electron propagation only for spinors lying along a certain direction. For spins in the opposite d

J. Bonca, S. Maekawa, T. Tohyama

We develop an efficient numerical method for the description of a single-hole motion in the antiferromagnetic background. The method is free of finite-size effects and allows calculation of physical properties at an arbitrary wavevector. Methodical increase of the functional space leads to results that are valid in the thermodynamic limit. We found good agre

G. Di Domenico, H. Saudan, G. Bison, P. Knowles

We present an experimental study of the intrinsic magnetometric sensitivity of an optical/rf-frequency double resonance magnetometer in which linearly polarized laser light is used in the optical pumping and detection processes. We show that a semi-empirical model of the magnetometer can be used to describe the magnetic resonance spectra. Then, we present an

A. Di Mauro, B. Lund-Jensen, P. Martinengo, E. Nappi

The paper summarizes our latest progress in the development of newly introduced micro pattern gaseous detectors with resistive electrodes. These resistive electrodes protect the detector and the front-end electronics in case of occasional discharges and thus make the detectors very robust and reliable in operation. As an example, we describe in greater detai

L. Luthi, E. Pestelacci, M. Tomassini

We simulate the prisoner&#39;s dilemma and hawk-dove games on a real social acquaintance network. Using a discrete analogue of replicator dynamics, we show that surprisingly high levels of cooperation can be achieved, contrary to what happens in unstructured mixing populations. Moreover, we empirically show that cooperation in this network is stable with res

Xi-Han Li, Fu-Guo Deng, Hong-Yu Zhou

A general scheme for controlled teleportation of an arbitrary multi-qudit state with d-dimensional Greenberger-Horne-Zeilinger (GHZ) states is proposed. For an arbitrary m-qudit state, the sender Alice performs m generalized Bell-state projective measurements on her 2m qudits and the controllers need only take some single-particle measurements. The receiver

Ping Zhou, Xi-Han Li, Yu-Jie Liang, Fu-Guo Deng

We present a scheme for multiparty quantum secret sharing of a private key with pure entangled states and decoy photons. The boss, say Alice uses the decoy photons, which are randomly in one of the four nonorthogonal single-photon states, to prevent a potentially dishonest agent from eavesdropping freely. This scheme requires the parties of communication to

Markus Kasper, Daniel Apai, Markus Janson, Wolfgang Brandner

The paper presents results from a small survey of 22 young, nearby stars that was designed to detect substellar companions and ultimately giant extrasolar planets down to Jupiter masses. The targets are members of the Tucana and Beta Pictoris moving groups apart from the somewhat older star HIP 71395 that has a radial velocity trend suggesting a massive plan

Giorgio Parisi

In these lectures I will review some theoretical results that have been obtained for spin glasses. I will concentrate my attention on the formulation of the mean field approach and on its numerical and experimental verifications. I will present the various hypothesis at the basis of the theory and I will discuss their mathematical and physical status.

S. Recchi, Ch. Theis, P. Kroupa, G. Hensler

Context: Dwarf galaxies can arise from self-gravitating structures emerging from tidal tails. What fraction of the known dwarf galaxies in the Local Universe can have this origin is still a matter of debate. Aims: In our effort to understand the origin and evolution of tidal dwarf galaxies and their correspondence with local objects, the first step is to und

Y. J. Lei, L. M. Song, J. L. Qu, C. M. Zhang

The rms (root mean square) variability is the parameter for understanding the emission temporal properties of X-ray binaries (XRBs) and active galactic nuclei (AGN). The rms-flux relation with Rossi X-ray Timing Explorer (RXTE) data for the dips and nondip of black hole Cyg X-1 has been investigated in this paper. Our results show that there exist the linear

M. Batkova, I. Batko, K. Flachbart, K. Jurek

We present results of measurements of electrical, magnetic and thermal properties of EuB$_{5.99}$C$_{0.01}$. The observed anomalously large negative magnetoresistance as above, so below the Curie temperature of ferromagnetic ordering $T_C$ is attributed to fluctuations in carbon concentration. Below $T_C$ the carbon richer regions give rise to helimagnetic d

A. M. Swinbank, A. Edge, I. Smail, J. Stott

We analyse the first publicly released deep field of the UKIDSS Deep eXtragalactic Survey (DXS) to identify candidate galaxy over-densities at z~1 across ~1 sq. degree in the ELAIS-N1 field. Using I-K, J-K and K-3.6um colours we identify and spectroscopically follow-up five candidate structures with Gemini/GMOS and confirm they are all true over-densities wi

Nigel Hitchin

We define a sextic invariant J on the seven-dimensional space of degree three spherical harmonics and show that J is positive if and only if the nodal set of the spherical harmonic contains the vertices of exactly two regular icosahedra. The proof uses the geometry of the Clebsch diagonal cubic surface, Atiyah&#39;s classification of vector bundles on an ell

A. N. Antonov, M. V. Ivanov, M. B. Barbaro, J. A. Caballero

The superscaling analysis is extended to include quasielastic (QE) scattering via the weak neutral current of neutrinos and antineutrinos from nuclei. The scaling function obtained within the coherent density fluctuation model (used previously in calculations of QE inclusive electron and charge-changing (CC) neutrino scattering) is applied to neutral current

A. V. Novikov-Borodin

The hypothesis concerning the off-site continuum existence is investigated from the point of view of the mathematical theory of sets. The principles and methods of the mathematical description of the physical objects from different off-site continuums are introduced and discussed. There are also proposed the mathematical methods of the description of the off

Erwan Brugallé, Grigory Mikhalkin

In this note we compute some enumerative invariants of real and complex projective spaces by means of some enriched graphs called floor diagrams.

A. O. Sboychakov, Sergey Savel&#39;ev, A. L. Rakhmanov, K. I. Kugel

A two-band Hubbard model is used to describe the band structure and phase separation (PS) in multiband superconductors, especially in cuprates. We predict a large peak in the density of states at the Fermi level in the case of optimum doping, corresponding to the minimum energy difference between the centers of two hole bands. For strong interband hybridizat

David Branch, M. A. Troxel, David J. Jeffery, Kazuhito Hatano

A comparative study of spectra of 21 Type Ia supernovae (SNe Ia) obtained about one week before maximum light, and 8 spectra obtained 11 or more days before maximum, is presented. To a large extent the premaximum spectra exhibit the defining characteristics of the four groups defined in Paper II (core-normal, broad-line, cool, and shallow-silicon). Compariso

Yu. V. Bludov, V. A. Brazhnyi, V. V. Konotop

It is shown that inhomogeneous nonlinear interactions in a Bose-Einstein condensate loaded in an optical lattice can result in delocalizing transition in one dimension, what sharply contrasts to the known behavior of discrete and periodic systems with homogeneous nonlinearity. The transition can be originated either by decreasing the amplitude of the linear

J. H. Ho, Y. H. Lai, Y. H. Chiu, M. F. Lin

The Peierl&#39;s tight-binding model, with the band Hamiltonian matrix, is used to calculate the magnetoelectronic structure of a monolayergraphite. There are many flat Landau levels and some oscillatory Landau levels. The low Landau-level energies are characterized by a simple relation, not for others. State degeneracy is, respectively, fourfold degenerate

B. Cessac

We derive rigorous results describing the asymptotic dynamics of a discrete time model of spiking neurons introduced in \cite{BMS}. Using symbolic dynamic techniques we show how the dynamics of membrane potential has a one to one correspondence with sequences of spikes patterns (``raster plots&#39;&#39;). Moreover, though the dynamics is generically periodic

Hiroo Kenzaki, Macoto Kikuchi

Structural fluctuations in the thermal equilibrium of the kinesin motor domain are studied using a lattice protein model with Go interactions. By means of the multi-self-overlap ensemble (MSOE) Monte Carlo method and the principal component analysis (PCA), the free-energy landscape is obtained. It is shown that kinesins have two subdomains that exhibit parti

V. E. Adler, A. B. Shabat

We consider an hierarchy of integrable 1+2-dimensional equations related to Lie algebra of the vector fields on the line. The solutions in quadratures are constructed depending on $n$ arbitrary functions of one argument. The most interesting result is the simple equation for the generating function of the hierarchy which defines the dynamics for the negative

Peter McGregor, Michael Dopita, Ralph Sutherland, Tracy Beck

We present first results from the Near-infrared Integral Field Spectrograph (NIFS) located at Gemini North. For the active galaxies Cygnus A and Perseus A we observe rotationally-supported accretion disks and adduce the existence of massive central black holes and estimate their masses. In Cygnus A we also see remarkable high-excitation ionization cones domi

Yiping Dou, Nhu D Le, James V Zidek

This paper presents a dynamic linear model for modeling hourly ozone concentrations over the eastern United States. That model, which is developed within an Bayesian hierarchical framework, inherits the important feature of such models that its coefficients, treated as states of the process, can change with time. Thus the model includes a time--varying site