June 2007 arXiv papers — page 23

Estia Eichten, Kenneth Lane

The Tevatron experiments CDF and DO are close to making definitive statements about the technicolor discovery mode rho_T -> W pi_T for M(rho_T) <~ 230 GeV and M(pi_T) <~ 125 GeV. We propose new incisive tests for this mode and searches for others that may be feasible at the Tevatron and certainly are at the LHC. The other searches include two long discussed,

K. Yuasa, P. Facchi, H. Nakazato, I. Ohba

Lateral effects are analyzed in the antibunching of a beam of free non-interacting fermions. The emission of particles from a source is dynamically described in a 3D full quantum field-theoretical framework. The size of the source and the detectors, as well as the temperature of the source are taken into account and the behavior of the visibility is scrutini

Erhan Bayraktar, Hao Xing

We approximate the price of the American put for jump diffusions by a sequence of functions, which are computed iteratively. This sequence converges to the price function uniformly and exponentially fast. Each element of the approximating sequence solves an optimal stopping problem for geometric Brownian motion, and can be numerically computed using the clas

A. Martinez Torres, K. P. Khemchandani, E. Oset

We report four $Σ$&#39;s and three $Λ$&#39;s, in the 1500 - 1800 MeV region, as two meson - one baryon S-wave $(1/2)^+$ resonances. We solve Faddeev equations in the coupled channel approach. The invariant mass of one of the meson-baryon pairs and that of the three particles have been varied and peaks in the squared three body $T$-matrix have been found very

Ophir Flomenbom, Robert J. Silbey

Single molecule data made of on and off events are ubiquitous. Famous examples include enzyme turnover, probed via fluorescence, and opening and closing of ion-channel, probed via the flux of ions. The data reflects the dynamics in the underlying multi-substate on-off kinetic scheme (KS) of the process, but the determination of the underlying KS is difficult

V. Belokurov, N. W. Evans, A. Moiseev, L. J. King

We report the discovery of an almost complete Einstein ring of diameter 10&#34; in Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5). Spectroscopic data from the 6m telescope of the Special Astrophysical Observatory reveals that the deflecting galaxy has a line-of-sight velocity dispersion in excess of 400 km/s and a redshift of 0.444, whilst the source i

R. Bruce, A. Drees, W. Fischer, S. Gilardoni

We report the first observations of beam losses due to bound-free pair production at the interaction point of a heavy-ion collider. This process is expected to be a major luminosity limit for the Large Hadron Collider (LHC) when it operates with 208Pb82+ ions because the localized energy deposition by the lost ions may quench superconducting magnet coils. Me

CLEO Collaboration, D. Cronin-Hennessy

We present measurements of decay matrix elements for hadronic transitions of the form Upsilon(nS) -> pi pi Upsilon(mS) where (n, m) = (3, 1), (2, 1), and (3, 2). We reconstruct charged and neutral pion modes with the final state Upsilon decaying to either mu+mu- or e+e-. Dalitz plot distributions for the twelve decay modes are fit individually as well as joi

Maciej Misiorny, Józef Barnas

Magnetic switching of a single-molecule magnet (SMM) due to spin-polarized current is investigated theoretically. The charge transfer between the electrodes takes place via the lowest unoccupied molecular orbital (LUMO) of the SMM. Generally, the double occupancy of the LUMO level, and a finite on-site Coulomb repulsion, is taken into account. Owing to the e

Lahcen Assoud, René Messina, Hartmut Löwen

The phase diagram of binary mixtures of particles interacting via a pair potential of parallel dipoles is computed at zero temperature as a function of composition and the ratio of their magnetic susceptibilities. Using lattice sums, a rich variety of different stable crystalline structures is identified including $A_mB_n$ structures. [$A$ $(B)$ particles co

Gregory Gabadadze, Rachel A. Rosen

We consider Bose-Einstein condensation of massive electrically charged scalars in a uniform background of charged fermions. We focus on the case when the scalar condensate screens the background charge, while the net charge of the system resides on its boundary surface. A distinctive signature of this substance is that the photon acquires a Lorentz-violating

Martin Lüscher

The spontaneous breaking of chiral symmetry in QCD is known to be linked to a non-zero density of eigenvalues of the massless Dirac operator near the origin. Numerical studies of two-flavour QCD now suggest that the low quark modes are locally coherent to a certain extent. As a consequence, the modes can be simultaneously deflated, using local projectors, wi

Sang Pyo Kim, Hyun Kyu Lee

In scalar QED we study the Schwinger pair production from an initial ensemble of charged bosons when an electric field is turned on for a finite period together with or without a constant magnetic field. The scalar QED Hamiltonian depends on time through the electric field, which causes the initial ensemble of bosons to evolve out of equilibrium. Using the L

Kari Enqvist, Niko Jokela, Esko Keski-Vakkuri, Lotta Mether

We investigate decaying D-branes as the origin of the thermal string gas of string gas cosmology. We consider initial configurations of low-dimensional branes and argue that they can time evolve to thermal string gas. We find that there is a range in the weak string coupling and fast brane decay time regimes, where the initial configuration could drive the e

Anna A. Dushistova, Nikolai G. Moshchevitin

Let $ x = [0;a_1,a_2,...]$ be the decomposition of the irrational number $x \in [0,1]$ into regular continued fraction. Then for the derivative of the Minkowski function $?(x)$ we prove that $?&#39;(x) = +\infty$ provided $ \limsup_{t\to \infty}\frac{a_1+...+a_t}{t} <κ_1 =\frac{2\log λ_1}{\log 2} = 1.388^+$, and $?&#39;(x) = 0$ provided $ \liminf_{t\to \inft

Philippe Grandclement, Jérôme Novak

Equations arising in General Relativity are usually too complicated to be solved analytically and one has to rely on numerical methods to solve sets of coupled partial differential equations. Among the possible choices, this paper focuses on a class called spectral methods where, typically, the various functions are expanded onto sets of orthogonal polynomia

Alexander Yu. Vlasov

In this work are considered some questions of Monte-Carlo modeling on nontrivial bundles. As a basic example is used problem of generation of straight lines in 3D space, related with modeling of interaction of a solid body with a flux of particles and with some other tasks. Space of lines used in given model is example of nontrivial fiber bundle, that is equ

M. Gilowski, Ch. Schubert, M. Zaiser, W. Herr

We present and investigate different external cavity diode laser (ECDL) configurations for the manipulation of neutrals atoms, wavelength-stabilized by a narrow-band high transmission interference filter. A novel diode laser, providing high output power of more than 1 W, with a linewidth of less than 200 kHz, based on a self-seeded tapered amplifier chip has

Weronika Jas, Stanislaw Mrowczynski

Evolution of anisotropy in momentum and coordinate space of the parton system produced in relativistic heavy-ion collisions is discussed within the free-streaming approximation. The momentum distribution evolves from the prolate shape - elongated along the beam - to the oblate one - squeezed along the beam. At the same time the eccentricity in the coordinate

A. Setyadi

For $n \geq 2$ and a local field $K$, let $Δ_n$ denote the affine building naturally associated to the symplectic group ${\rm Sp}_n(K)$. We compute the spectral radius of the subgraph $Y_n$ of $Δ_n$ induced by the special vertices in $Δ_n$, from which it follows that $Y_n$ is an analogue of a family of expanders and is non-amenable.

Z. Lozanov--Crvenkovic, D. Perisic, M. Taskovic

It was shown recently that the space isomorphic with an Gelfand Shilov space is well adapted for the use in quantum field theory with a fundamental length. It is our believe that all Gelfand Shilov spaces, especially those with quasianalytic test function spaces, are good domains for the quantum field theory. The theory requires technical results from the th

A. Zazunov, N. Didier, F. W. J. Hekking

The effect of quantum fluctuations on the current-voltage characteristics of Josephson junctions and superconducting nanowires is studied in the underdamped limit. Quantum fluctuations induce transitions between a Coulomb--blockade and a supercurrent branch, and can significantly modify the shape of current-voltage characteristics in the case of a highly res

S. Hofferberth, I. Lesanovsky, B. Fischer, T. Schumm

Low-dimensional systems are beautiful examples of many-body quantum physics. For one-dimensional systems the Luttinger liquid approach provides insight into universal properties. Much is known of the equilibrium state, both in the weakly and strongly interacting regime. However, it remains a challenge to probe the dynamics by which this equilibrium state is

Pere Pascual Gainza, Llorenc Rubio i Pons

In this note we apply Guillen-Navarro descent theorem, \cite{GN02}, to define a descent variant of the algebraic $K$-theory of varieties over a field of characteristic zero, $\mathcal{KD}(X)$, which coincides with $\mathcal{K}(X)$ for smooth varieties. After a result of Haesemeyer, this new theory is equivalent to the homotopy algebraic $K$-theory introduced

Rainer Heise, Harald G Svendsen

We study the fermionic sector of a probe D8-brane in the supergravity background made of D4-branes compactified on a circle with supersymmetry broken explicitly by the boundary conditions. At low energies the dual field theory is effectively four-dimensional and has proved surprisingly successful in recovering qualitative and quantitative properties of QCD.

Vishnu Jejjala, Michael Kavic, Djordje Minic

We review our recent proposal for a background independent formulation of a holographic theory of quantum gravity. The present review incorporates the necessary background material on geometry of canonical quantum theory, holography and spacetime thermodynamics, Matrix theory, as well as our specific proposal for a dynamical theory of geometric quantum mecha

Emmanuel Wagner

This paper has been withdrawn by the author due to an error in the proof of Theorem 1.

S. H. Naqib

The effect of Zn substitution on the superconducting transition temperature, Tc, was investigated for the sintered Y1-xCaxBa2(Cu1-yZny)3O7-delta compounds over a wide range of hole concentration per CuO2 plane, p. Ca substitution enabled us to study the deeply overdoped region. p was changed by changing the oxygen deficiency (delta). A strongly p-dependent r

S. Portolan, O. Di Stefano, S. Savasta, F. Rossi

We present a systematic theory of Coulomb-induced correlation effects in the nonlinear optical processes within the strong-coupling regime. In this paper we shall set a dynamics controlled truncation scheme \cite{Axt Stahl} microscopic treatment of nonlinear parametric processes in SMCs including the electromagnetic field quantization. It represents the star

Markus Diefenthaler

Azimuthal single-spin asymmetries (SSA) in semi-inclusive electroproduction of pi-mesons and charged K-mesons in deep-inelastic scattering of positrons and electrons on a transversely polarised hydrogen target were observed. Significant SSA amplitudes for both the Collins and the Sivers mechanism are presented for the full data set recorded with transverse t

Marti Lahoz

The purpose of this article is to show that the Castelnuovo theory for abelian varieties, developed by G. Pareschi and M. Popa, can be infinitesimalized. More precisely, we prove that an irreducible principally polarized abelian variety has a finite scheme in extremal position, in the sense of Castelnuovo theory for abelian varieties, if, and only if, it is

J. M. Kumpula, J. Saramaki, K. Kaski, J. Kertesz

Detecting community structure in real-world networks is a challenging problem. Recently, it has been shown that the resolution of methods based on optimizing a modularity measure or a corresponding energy is limited; communities with sizes below some threshold remain unresolved. One possibility to go around this problem is to vary the threshold by using a tu

Huaxin Lin

Let $X$ be a compact metric space and let $Λ$ be a $\Z^k$ ($k\ge 1$) action on $X.$ We give a solution to a version of Voiculescu&#39;s problem of AF-embedding: The crossed product $C(X)\rtimes_Λ\Z^k$ can be embedded into a unital simple AF-algebra if and only if $X$ admits a strictly positive $Λ$-invariant Borel probability measure. Let $C$ be a unital AH-a

Mikhail Zaidenberg

This survey addresses pluri-periodic harmonic functions on lattices with values in a positive characteristic field. We mention, as a motivation, the game "Lights Out" following the work of Sutner, Goldwasser-Klostermeyer-Ware, Barua-Ramakrishnan-Sarkar, Hunzikel-Machiavello-Park e.a.; see also 2 previous author's preprints for a more detailed account. Our ap

Simon J. Devitt, Andrew D. Greentree, Radu Ionicioiu, Jeremy L. O&#39;Brien

Photonic entanglement has a wide range of applications in quantum computation and communication. Here we introduce a new device: the &#34;photonic module&#34;, which allows for the rapid, deterministic preparation of a large class of entangled photon states. The module is an application independent, &#34;plug and play&#34; device, with sufficient flexibility

Masato Okado, Anne Schilling

Using the methods of Kang et al. and recent results on the characters of Kirillov-Reshetikhin modules by Nakajima and Hernandez, the existence of Kirillov-Reshetikhin crystals B^{r,s} is established for all nonexceptional affine types. We also prove that the crystals B^{r,s} of type B_n^{(1)}, D_n^{(1)}, and A_{2n-1}^{(2)} are isomorphic to recently construc

K. Takubo, T. Mizokawa, J. -Y. Son, Y. Nambu

We have studied the electronic structure of the Ni triangular lattice in NiGa$_2$S$_4$ using photoemission spectroscopy and subsequent model calculations. The cluster-model analysis of the Ni 2$p$ core-level spectrum shows that the S 3$p$ to Ni 3$d$ charge-transfer energy is $\sim$ -1 eV and the ground state is dominated by the $d^9L$ configuration ($L$ is a

Qing-Guo Huang

We conjecture that the inflation models with trans-Planckian excursions in the field space should be in the swampland. We check this conjecture in a few examples and investigate the constraints on the spectral index for the slow-roll inflation model in string landscape where the variation of inflaton during the period of inflation is less than the Planck sca

Jérôme Dubois, Vu Huynh, Yoshikazu Yamaguchi

This paper gives an explicit formula for the SL_2(C)-non-abelian Reidemeister torsion as defined in [Dub06] in the case of twist knots. For hyperbolic twist knots, we also prove that the non-abelian Reidemeister torsion at the holonomy representation can be expressed as a rational function evaluated at the cusp shape of the knot.

Wen Zhao

We discuss the evolution of holographic hessence model, which satisfies the holographic principle and can naturally realizes the equation of state crossing -1. By discussing the evolution of the models in the $w w&#39;$ plane, we find that, if $c\geq1$, $w_{he}\geq-1$ and $\dot{V}<0$ keep for all time, which are quintessence-like. However, if $c<-1$, which m

Wick Haxton, Cecilia Lunardini

Semi-leptonic electroweak interactions in nuclei - such as βdecay, μcapture, charged- and neutral-current neutrino reactions, and electron scattering - are described by a set of multipole operators carrying definite parity and angular momentum, obtained by projection from the underlying nuclear charge and three-current operators. If these nuclear operators a

Javier Trujillo Bueno, Nataliya Shchukina

One of the greatest challenges in solar and stellar physics in coming years will be to observe the Second Solar Spectrum with a spatial resolution significantly better than 1 arcsec. This type of scattering polarization observations would probably allow us to discover hitherto unknown aspects of the Sun&#39;s hidden magnetism. Here we report on some theoreti

N. Wex, M. Kramer

In this paper we develop a consistent, phenomenological methodology to measure preferred-frame effects (PFEs) in binary pulsars that exhibit a high rate of periastron advance. We show that in these systems the existence of a preferred frame for gravity leads to an observable characteristic `signature&#39; in the timing data, which uniquely identifies this ef

Boris Shoikhet

Let $α$ be a polynomial Poisson bivector on a finite-dimensional vector space $V$ over $\mathbb{C}$. Then Kontsevich [K97] gives a formula for a quantization $f\star g$ of the algebra $S(V)^*$. We give a construction of an algebra with the PBW property defined from $α$ by generators and relations. Namely, we define an algebra as the quotient of the free tens

Joanna I. Sułkowska, Piotr Sułkowski, Piotr Szymczak, Marek Cieplak

We perform theoretical studies of stretching of 20 proteins with knots within a coarse grained model. The knot&#39;s ends are found to jump to well defined sequential locations that are associated with sharp turns whereas in homopolymers they diffuse around and eventually slide off. The waiting times of the jumps are increasingly stochastic as the temperatur

Rodolfo H. Barbá, Julia I. Arias

Aims: We search for direct evidence of ongoing star formation by accretion in the Lagoon Nebula (M8), using optical wide-field narrow-band imaging obtained at La Silla Observatory. Methods: We examine [SII] and Halpha images for line-emission features that could be interpreted as signatures of outflow activity of the exciting sources. Results: We discover fi

A. F. Boden, G. Torres, A. I. Sargent, R. L. Akeson

We report on interferometric and radial-velocity observations of the double-lined 51-d period binary (A) component of the quadruple pre-main sequence (PMS) system V773 Tau. With these observations we have estimated preliminary visual and physical orbits of the V773 Tau A subsystem. Among other parameters, our orbit model includes an inclination of 66.0 $\pm$

M. A. Castellanos-Beltran, K. W. Lehnert

We create a Josephson parametric amplifier from a transmission line resonator whose inner conductor is made from a series SQUID array. By changing the magnetic flux through the SQUID loops, we are able to adjust the circuit&#39;s resonance frequency and, consenquently, the center of the amplified band, between 4 and 7.8 GHz. We observe that the amplifier has

A. Lesfari

The classical definition of Prym varieties deals with the unramified covers of curves. The aim of the present paper is to give explicit algebraic descriptions of the Prym varieties associated to ramified double covers of algebraic curves. We make a careful study of the connection with the concept of algebraic completely integrable systems and we apply the me

I. Nasser, M. S. Abdelmonem, H. Bahlouli, A. D. Alhaidari

This is the first in a series of articles in which we study the rotating Morse potential model for diatomic molecules in the tridiagonal J-matrix representation. Here, we compute the bound states energy spectrum by diagonalizing the finite dimensional Hamiltonian matrix of H2, LiH, HCl and CO molecules for arbitrary angular momentum. The calculation was perf

William Ott

We prove that spiral sinks (stable foci of vector fields) can be transformed into strange attractors exhibiting sustained, observable chaos if subjected to periodic pulsatile forcing. We show that this phenomenon occurs in the context of periodically-kicked degenerate supercritical Hopf bifurcations. The results and their proofs make use of a new multi-param

Peng Gao

We study a weighted version of Carleman&#39;s inequality via Carleman&#39;s original approach. As an application of our result, we prove a conjecture of Bennett.

Hsiao-Wen Chen, J. X. Prochaska, Joshua S. Bloom

Recent observations suggest that global properties of the host galaxies for long-duration gamma-ray bursts (GRBs) are particularly well-suited for creating the massive star progenitors of these GRBs. Motivated by the hypothesis that massive young star clusters located in metal-poor, low-metallicity galaxies are a natural birthsite for GRB progenitors, we pre

Karin M. Sandstrom, J. E. G. Peek, Geoffrey C. Bower, Alberto D. Bolatto

We determine the parallax and proper motion of the flaring, non-thermal radio star GMR A, a member of the Orion Nebula Cluster, using Very Long Baseline Array observations. Based on the parallax, we measure a distance of 389 +24/-21 parsecs to the source. Our measurement places the Orion Nebula Cluster considerably closer than the canonical distance of 480 +

D0 Collaboration, V. Abazov

We report a measurement of the Lambda_b lifetime using a sample corresponding to 1.3 fb$^{-1}$ of data collected by the D0 experiment in 2002--2006 during Run II of the Fermilab Tevatron collider. The Lambda_b baryon is reconstructed via the decay Lambda_b -> mu nu Lambda_c X. Using $4437 \pm 329$ signal candidates, we measure the Lambda_b lifetime to be $τ(

Gilles Brassard, Anne Broadbent, Joseph Fitzsimons, Sebastien Gambs

We present the first protocol for the anonymous transmission of a quantum state that is information-theoretically secure against an active adversary, without any assumption on the number of corrupt participants. The anonymity of the sender and receiver is perfectly preserved, and the privacy of the quantum state is protected except with exponentially small p

Jesús A. De Loera, Raymond Hemmecke, Matthias Köppe, Robert Weismantel

We show the existence of a fully polynomial-time approximation scheme (FPTAS) for the problem of maximizing a non-negative polynomial over mixed-integer sets in convex polytopes, when the number of variables is fixed. Moreover, using a weaker notion of approximation, we show the existence of a fully polynomial-time approximation scheme for the problem of max

G. Piacente, G. Q. Hai

Electron relaxation, induced by acoustic phonons, is studied for coupled quantum rings in the presence of external fields, both electric and magnetic. We address the problem of a single electron in vertically coupled GaAs quantum rings. Electron-phonon interaction is accounted for both deformation potential and piezoelectric field coupling mechanisms. Depend

Karim Mounirh

By generalizing the method used by Tignol and Amitsur in [TA85], we determine necessary and sufficient conditions for an arbitrary tame central division algebra D over a Henselian valued field E to have Kummer subfields [Corollary 2.11 and Corollary 2.12]. We prove also that if D is a tame semiramified division algebra of prime power degree p^n over E such t

W. P. Tan, J. L. Fisker, J. Goerres, M. Couder

The breakout reaction $^{15}$O($α,γ$)$^{19}$Ne, which regulates the flow between the hot CNO cycle and the rp-process, is critical for the explanation of the burst amplitude and periodicity of X-ray bursters. We report on the first successful measurement of the critical $α$-decay branching ratios of relevant states in $^{19}$Ne populated via $^{19}$F($^3$He,

We-Fu Chang, John N. Ng, Jackson M. S. Wu

We consider the phenomenological consequences of a hidden Higgs sector extending the Standard Model (SM), in which the matter content are uncharged under the SM gauge groups. We consider a simple case where the hidden sector is gauged under a U(1) with one Higgs singlet. The only couplings between SM and the hidden sector are through mixings between the neut

Bernard J. Rauscher, Ori Fox, Pierre Ferruit

We describe how the James Webb Space Telescope (JWST) Near-Infrared Spectrograph&#39;s (NIRSpec&#39;s) detectors will be read out, and present a model of how noise scales with the number of multiple non-destructive reads sampling-up-the-ramp. We believe that this noise model, which is validated using real and simulated test data, is applicable to most astron

J. Krticka, Z. Mikulasek, J. Zverko, J. Ziznovsky

We simulate light curves of the helium strong chemically peculiar star HD 37776 assuming that the observed periodic light variations originate as a result of inhomogeneous horizontal distribution of chemical elements on the surface of a rotating star. We show that chemical peculiarity influences the monochromatic radiative flux, mainly due to bound-free proc

L. Federici, M. Bellazzini, S. Galleti, F. Fusi Pecci

We present a study of the density profile of the remote M31 globular cluster B514, obtained from HST/ACS observations. Coupling the analysis of the distribution of the integrated light with star counts we can reliably follow the profile of the cluster out to r~35&#34;, corresponding to ~130pc. The profile is well fitted, out to ~15 core radii, by a King Mode

W. A. Horowitz, M. Gyulassy

Heavy quark jet quenching in nuclear collisions at LHC is predicted and compared using the classical gravity AdS/CFT correspondence and Standard Model perturbative QCD. The momentum independence and inverse quark mass dependence of the drag coefficient in AdS/CFT differs substantially from the characteristic log(pT/M)/pT variation of the drag in QCD. We prop

Johan Alwall, Pavel Demin, Simon de Visscher, Rikkert Frederix

We present the latest developments of the MadGraph/MadEvent Monte Carlo event generator and several applications to hadron collider physics. In the current version events at the parton, hadron and detector level can be generated directly from a web interface, for arbitrary processes in the Standard Model and in several physics scenarios beyond it (HEFT, MSSM

V. A. Benderskii, L. A. Falkovsky, E. I. Kats

We investigate time evolution of prepared vibrational state (system) coupled to a reservoir with dense spectrum of its vibrational states. We assume that the reservoir has an equidistant spectrum, and the system - reservoir coupling matrix elements are independent of the reservoir states. The analytical solution manifests three regimes of the evolution for t

Marco Picariello, Bhag C. Chauhan, Joao Pulido, Emilio Torrente-Lujan

The complementarity between the quark and lepton mixing matrices is shown to provide robust predictions. We obtain these predictions by first showing that the matrix V_M, product of the quark (CKM) and lepton (PMNS) mixing matrices, may have a zero (1,3) entry which is favored by experimental data. We obtain that any theoretical model with a vanishing (1,3)

Matthew Headrick, Toby Wiseman

The second del Pezzo surface is known by work of Tian-Zhu and Wang-Zhu to admit a unique Kaehler-Ricci soliton. Applying a method described in hep-th/0703057, we use Ricci flow to numerically compute that soliton metric. We numerically compute the value of its Perelman entropy (or Gaussian density).

Shuai Chen, Yu-Ao Chen, Bo Zhao, Zhen-Sheng Yuan

We demonstrate a novel way to efficiently and very robust create an entanglement between an atomic and a photonic qubit. A single laser beam is used to excite one atomic ensemble and two different spatial modes of scattered Raman fields are collected to generate the atom-photon entanglement. With the help of build-in quantum memory, the entanglement still ex

Jonathan Irwin, Suzanne Aigrain, Simon Hodgkin, Keivan G. Stassun

We report the discovery of a low-mass (0.26 +/- 0.02, 0.15 +/- 0.01 Msol) pre-main-sequence eclipsing binary with a 5.3 day orbital period. JW 380 was detected as part of a high-cadence time-resolved photometric survey (the Monitor project) using the 2.5m Isaac Newton Telescope and Wide Field Camera for a survey of a single field in the Orion Nebula Cluster

Shrawan Kumar, John R. Stembridge

We show that any bijection between two root systems that preserves angles (but not necessarily lengths) gives rise to inequalities relating tensor product multiplicities for the corresponding complex semisimple Lie groups (or Lie algebras). We explain the inequalities in two ways: combinatorially, using Littelmann&#39;s Path Model, and geometrically, using i

E. E. Rigby, I. A. Snellen, P. N. Best

With the goal of identifying high redshift radio galaxies with FRI classification, here are presented high resolution, wide-field radio observations, near infra-red and optical imaging and multi-object spectroscopy of two fields of the Leiden-Berkeley Deep Survey. These fields, Hercules.1 and Lynx.2, contain a complete sample of 81 radio sources with S(1.4 G

A. G. Ramm

A method is proposed to create materials with a desired refraction coefficient, possibly negative one. The method consists of embedding into a given material small particles. Given $n_0(x)$, the refraction coefficient of the original material in a bounded domain $D \subset \R^3$, and a desired refraction coefficient $n(x)$, one calculates the number $N(x)$ o

Micah B. Milinovich, Nathan Ng

Assuming the Riemann Hypothesis, we establish lower bounds for moments of the derivative of the Riemann zeta-function averaged over the non-trivial zeros of $ζ(s)$. Our proof is based upon a recent method of Rudnick and Soundararajan that provides analogous bounds for moments of $L$-functions at the central point, averaged over families.

Massimo Giulietti, Gabor Korchmaros

In his investigation on large $K$-automorphism groups of an algebraic curve, Stichtenoth obtained an upper bound on the order of the first ramification group of an algebraic curve $\cX$ defined over an algebraically closed field of characteristic $p$. Stichtenoth&#39;s bound has raised the problem of classifying all $\K$-automorphism groups $G$ of $\cX$ with

E. G. L. R. Vaz, Irene Brito

The elasticity difference tensor, used in [1] to describe elasticity properties of a continuous medium filling a space-time, is here analysed from the point of view of the space-time connection. Principal directions associated with this tensor are compared with eigendirections of the material metric. Examples concerning spherically symmetric and axially symm

Carlos Kozameh, E. T. Newman, Gilberto Silva-Ortigoza

We describe here what appears to be a new structure that is hidden in all asymptotically vanishing Maxwell fields possessing a non-vanishing total charge. Though we are dealing with real Maxwell fields on real Minkowski space nevertheless, directly from the asymptotic field one can extract a complex analytic world-line defined in complex Minkowski space that

J. M. Espinar, J. A. Galvez, P. Mira

Our first objective in this paper is to give a natural formulation of the Christoffel problem for hypersurfaces in $H^{n+1}$, by means of the hyperbolic Gauss map and the notion of hyperbolic curvature radii for hypersurfaces. Our second objective is to provide an explicit equivalence of this Christoffel problem with the famous problem of prescribing scalar

E. Macias-Virgos, E. Sanmartin-Carbon

Let (M,F) be a foliated manifold. We study the relationship between the basic cohomology Hb(M,F) of the foliation and the De Rham cohomology H(DF) of the space of leaves M/F as a quotient diffeological space. We prove that for an arbitrary foliation there is a morphism from H(DF) to Hb(M,F). It is an isomorphism when F is a Q-foliation.

Fabrizio Buscemi, Paolo Bordone, Andrea Bertoni

We study theoretically the entanglement created in a scattering between an electron, incoming from a source lead, and another electron bound in the ground state of a quantum dot, connected to two leads. We analyze the role played by the different kinds of resonances in the transmission spectra and by the number of scattering channels, into the amount of quan

Nicolas Gresset, Loic Brunel, Joseph Boutros

The space-time bit-interleaved coded modulation (ST-BICM) is an efficient technique to obtain high diversity and coding gain on a block-fading MIMO channel. Its maximum-likelihood (ML) performance is computed under ideal interleaving conditions, which enables a global optimization taking into account channel coding. Thanks to a diversity upperbound derived f

Hans G. Kaper, Shouhong Wang, Masoud Yari

This article is concerned with the stability and long-time dynamics of structures arising from a structureless state. The paradigm is suggested by developmental biology, where morphogenesis is thought to result from a competition between chemical reactions and spatial diffusion. A system of two reaction-diffusion equations for the concentrations of two morph

B. Ranguelov, J. J. Metois, P. Muller

Using recently proposed improvements of Reflection Electron Microsopy (REM) we study in perfectly controlled thermodynamics conditions spiral shapes and spirals on Si(111) surface. It is shown that the new method named low distortion reflection electron microscopy (LODREM) is a powerful instrument, resolving in much more details (compared with REM) growth or

Eugenia Cheng, Nick Gurski

We continue the project begun in ``The periodic table of $n$-categories for low dimensions I&#39;&#39; by examining degenerate tricategories and comparing them with the structures predicted by the Periodic table. For triply degenerate tricategories we exhibit a triequivalence with the partially discrete tricategory of commutative monoids. For the doubly dege

Pauli Virtanen, Tero T. Heikkilä

Attaching a superconductor in good contact with a normal metal makes rise to a proximity effect where the superconducting correlations leak into the normal metal. An additional contact close to the first one makes it possible to carry a supercurrent through the metal. Forcing this supercurrent flow along with an additional quasiparticle current from one or m

J. J. Metois, P. Muller

Experimental determination of absolute surface energies remains a challenge. We propose a simple method based on two independent measurements on 3D and 2D equilibrium shapes completed by the analysis of the thermal fluctuation of an isolated step. Using then basic equations (Wulff&#39; theorem, Gibbs-Thomson equation, thermodynamics fluctuation of an isolate

R. Messina, M. A. Jivulescu, A. Messina, A. Napoli

A new generalization of Dawson&#39;s integral function based on the link between a Riccati nonlinear differential equation and a second-order ordinary differential equation is reported. The MacLaurin expansion of this generalized function is built up and to this end an explicit formula for a generic cofactor of a triangular matrix is deduced.

J. J. Metois, A. Saul, P. Muller

While measurements of the polar dependence of the surface free energy are easily available, measurements of the whole polar dependence of the surface stress of a crystal do not exist. In this paper is presented a new procedure that allows, for the first time, the experimental determination of the surface stress polar dependence of a crystal. For this purpose

B. Stelzer, G. Micela

2MASS J11011926-7732383 AB (hereafter 2M1101AB), located in the Cha I star forming region, is a rare wide-separation brown dwarf binary. XMM-Newton and Chandra observations of 2M1101AB have allowed us to examine the influence of physical parameters (mass, bolometric luminosity and effective temperature) on X-ray emission from a coeval pair of substellar obje

Bernard Silvestre-Brac, Vincent Mathieu

In their textbook, Suzuki and Varga [Y. Suzuki and K. Varga, {\em Stochastic Variational Approach to Quantum-Mechanical Few-Body Problems} (Springer, Berlin, 1998)] present the stochastic variational method in a very exhaustive way. In this framework, the so-called correlated gaussian bases are often employed. General formulae for the matrix elements of vari

David E. Hogg, Morton S. Roberts, Martha P. Haynes, Ronald J. Maddalena

In order to investigate the contribution of diffuse components to their total HI emission, we have obtained high precision HI line flux densities with the 100m Green Bank Telescope for a sample of 100 isolated spiral and irregular galaxies which we have previously observed with the 43m telescope. A comparison of the observed HI line fluxes obtained with the

Bau-Sen Du

Let f(x) be a continuous function from a compact real interval into itself with a periodic orbit of minimal period m, where m is not an integral power of 2. Then, by Sharkovsky&#39;s theorem, for every positive integer n with m \prec n in the Sharkovsky&#39;s ordering defined below, a lower bound on the number of periodic orbits of f(x) with minimal period n

Rafael Dias Vilela, Tamás Tél, Alessandro P. S. de Moura, Celso Grebogi

Aerosols under chaotic advection often approach a strange attractor. They move chaotically on this fractal set but, in the presence of gravity, they have a net vertical motion downwards. In practical situations, observational data may be available only at a given level, for example at the ground level. We uncover two fractal signatures of chaotic advection o

M. A. Jivulescu, A. Messina, A. Napoli, F. Petruccione

The exact solution of a Cauchy problem related to a linear second-order difference equation with constant noncommutative coefficients is reported.

Jean-Yves Marion, Romain Pechoux

A sup-interpretation is a tool which provides an upper bound on the size of a value computed by some symbol of a program. Sup-interpretations have shown their interest to deal with the complexity of first order functional programs. For instance, they allow to characterize all the functions bitwise computable in Alogtime. This paper is an attempt to adapt the

Jia Yuan

In this paper we study the magneto-micropolar fluid equations in $\R^3$, prove the existence of the strong solution with initial data in $H^s(\R^3)$ for $s> {3/2}$, and set up its blow-up criterion. The tool we mainly use is Littlewood-Paley decomposition, by which we obtain a Beale-Kato-Majda type blow-up criterion for smooth solution $(u,ω,b)$ which relies

Stephan Falke, Eberhard Tiemann, Christian Lisdat

Asymptotic levels of the A $^1Σ_u^+$ state of the two isotopomers $^{39}{\rm K}_2$ and $^{39}{\rm K}^{41}{\rm K}$ up to the dissociation limit are investigated with a Doppler-free high resolution laser-spectroscopic experiment in a molecular beam. The observed level structure can be reproduced correctly only if a mass dependent correction term is introduced

N. A. Matveeva, A. V. Taichenachev, A. M. Tumaikin, V. I. Yudin

The semiclassical theory of laser cooling is applied for the analysis of cooling of unbound atoms with the values of the ground and exited state angular moments 1/2 in a one-dimensional nondissipative optical lattice. We show that in the low-saturation limit with respect to the pumping field a qualitative interpretation of the cooling mechanisms can be made

A. Sollima, G. Beccari, F. R. Ferraro, F. Fusi Pecci

We used deep observations collected with ACS@HST to derive the fraction of binary systems in a sample of thirteen low-density Galactic globular clusters. By analysing the color distribution of Main Sequence stars we derived the minimum fraction of binary systems required to reproduce the observed color-magnitude diagram morphologies. We found that all the an