May 2008 arXiv papers — page 35

Jerome Le Ny, Munther Dahleh, Eric Feron

We extend a relaxation technique due to Bertsimas and Nino-Mora for the restless bandit problem to the case where arbitrary costs penalize switching between the bandits. We also construct a one-step lookahead policy using the solution of the relaxation. Computational experiments and a bound for approximate dynamic programming provide some empirical support f

T. Csorgo, M. I. Nagy, M. Csanad

A new class of simple and exact solutions of relativistic hydrodynamics is presented, and the consequences are explored in data analysis. The effects of longitudinal work and acceleration are taken into account in an advanced estimate of the initial energy density and the life-time of the reaction.

Dragos Ghioca, Thomas J. Tucker

We prove a dynamical version of the Mordell-Lang conjecture for subvarieties of quasiprojective varieties X, endowed with the action of a morphism f:X --> X. We use an analytic method based on the technique of Skolem, Mahler, and Lech, along with results of Herman and Yoccoz from nonarchimedean dynamics.

S. V. Syzranov, Yu. Makhlin

We show that geometric phases may be generated in a quantum system subject to noise by adiabatic manipulations of the fluctuating fields, e.g., by variation of the system-environment coupling. For a two-state quantum system we express this phase in terms of the geometry of the path, traversed by the slowly varying direction and amplitude of the fluctuations.

J. L. Racusin, S. V. Karpov, M. Sokolowski, J. Granot

Long duration gamma-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of a massive star. Over the last forty years, our understanding of the GRB phenomenon has progressed dramatically; nevertheless, fortuitous circumstances occasio

Su-Ion Ih, Thomas J. Tucker

Let K be a number field with algebraic closure K-bar, let S be a finite set of places of K containing the archimedean places, and let f be a Chebyshev polynomial. We prove that if a in K-bar is not preperiodic, then there are only finitely many preperiodic points b in K-bar which are S-integral with respect to a.

Iosif Polterovich

We prove an analogue of Pleijel's nodal domain theorem for piecewise analytic planar domains with Neumann boundary conditions. This confirms a conjecture made by Pleijel in 1956. The proof is a combination of Pleijel's original approach and an estimate due to Toth and Zelditch for the number of boundary zeros of Neumann eigenfunctions.

David M. Berns, Mark S. Rudner, Sergio O. Valenzuela, Karl K. Berggren

The energy-level structure of a quantum system plays a fundamental role in determining its behavior and manifests itself in a discrete absorption and emission spectrum. Conventionally, spectra are probed via frequency spectroscopy whereby the frequency νof a harmonic driving field is varied to fulfill the conditions ΔE = h ν, where the driving field is reson

Wen-Yu Wen

We study the holographically dual description of superconductor in (2+1)-dimensions in the presence of inhomogeneous magnetic field and observe that there exists type I and type II superconductor. A new feature of type changing is observed for type I superconductor near critical temperature.

Helmut Prodinger

We prove a continued fraction expansion for a certain $q$-tangent function that was conjectured by the present writer, then proved by Fulmek, now in a completely elementary way.

Paolo Lipparini

We extend to singular cardinals the model-theoretical relation $λ\stackrelκ{\Rightarrow} μ$ introduced in P. Lipparini, The compactness spectrum of abstract logics, large cardinals and combinatorial principles, Boll. Unione Matematica Italiana ser. VII, {\bf 4-B} 875--903 (1990). We extend some results obtained in Part II, finding equivalent conditions invol

Carlos E Roman-Velazquez, Bo E Sernelius

We present a series of calculations of van der Waals (vdW) forces that show non-additive behavior. The results reveal effects of geometrical dependences of the dispersion forces, that are in strong contradictions to the results from additivity approaches like the Lennard-Jones (LJ) pairwise interaction and the proximity force approximation (PFA). For the sim

Orfeu Bertolami, Carla Carvalho, Joao Laia

We show that a four-dimensional equation of state for a cosmological constant term arises from a perfect fluid in the bulk in the context of a gravity model where the scalar curvature is non-minimally coupled to the perfect fluid Lagrangian density. The four-dimensional theory is fully determined from the induced equations on the brane, subject to the bounda

Peter Horsch, Andrzej M. Oles', Louis Felix Feiner, Giniyat Khaliullin

We introduce a microscopic model which unravels the physical mechanisms responsible for the observed phase diagram of the $R$VO$_3$ perovskites. It reveals a nontrivial interplay between superexchange, the orbital-lattice coupling due to the GdFeO$_3$-like rotations of the VO$_6$ octahedra, and orthorhombic lattice distortions. We find that the lattice strai

Arnaud Beauville

We show that the algebraic group SL(2) acts on any polarized abelian variety A through correspondences. As a consequence we recover the action of SL(2) on the Chow group CH(A) (with rational coefficients), and this gives rise to Lefschetz type properties for algebraic cycles on A .

Shmuel Nussinov

The Froissart bound limmits the asymptotic s->infinity behavior of crossections by (π/t_0) ln ^2 (s/{(s_0)} where t_0 is the lightest exchanged particle, or more generally the nearest ssingularity, in the t channel. We suggest that in comparing this bound with data at energies less than those of LHC, gluebaall masses raather than the small pion mass should b

P. D. Andreev

The paper is the last in the cycle devoted to the solution of Alexandrov's problem for non-positively curved spaces. Here we study non-positively curved spaces in the sense of Busemann. We prove that if $X$ is geodesically complete connected at infinity proper Busemann space, then it has the following characterization of isometries. For any bijection $f:

Xuepeng Chen, Ralf Launhardt, Tyler L. Bourke, Thomas Henning

We present interferometric observations with resolution of ~3 arcsecs of the isolated, low-mass protostellar double cores CG30 and BHR71 in the N2$H+(1-0) line and at 3mm dust continuum, using the Australian Telescope Compact Array (ATCA). The results are complemented by infrared data from the Spitzer Space Telescope. In CG30, the 3mm dust continuum images r

V. Blavatska, C. von Ferber, Yu. Holovatch

We analyse scaling laws that govern macromolecules of different topology: polymer chains, homogeneous and miktoarm star polymers in a good solvent possibly constrained by a porous medium. The latter is modelled by long-range-correlated disorder with a pair correlation function g(r) that decays with a power law g(r) r^{-a} at large distances r. We show that t

S. V. Ludkovsky

This article is devoted to the investigation of wrap groups of connected fiber bundles over the fields of real $\bf R$, complex $\bf C$ numbers, the quaternion skew field $\bf H$ and the octonion algebra $\bf O$. Cohomologies of wrap groups and their structure are investigated. Sheaves of wrap groups are constructed and studied. Moreover, twisted cohomologie

Alexander N. Dranishnikov, Mikhail G. Katz, Yuli B. Rudyak

We prove that manifolds of Lusternik-Schnirelmann category 2 necessarily have free fundamental group. We thus settle a 1992 conjecture of Gomez-Larranaga and Gonzalez-Acuna, by generalizing their result in dimension 3, to all higher dimensions. We also obtain some general results on the relations between the fundamental group of a closed manifold M, the dime

Yoshio Tanigawa, Wenguang Zhai

Let $Δ(x)$ and $E(x)$ be error terms of the sum of divisor function and the mean square of the Riemann zeta function, respectively. In this paper their fourth power moments for short intervals of Jutila's type are considered. We get an asymptotic formula for $U$ in some range.

Wenguang Zhai

Let $Δ(x)$ be the error term of the Dirichlet divisor problem. An asymptotic formula with the error term $O(T^{53/28+ε})$ is established for the integral $\int_1^TΔ^4(x)dx.$ Similar results are also established for some other well-known error terms in the analytic number theory .

V. Mainieri, K. I. Kellermann, E. B. Fomalont, N. Miller

We present the optical and infrared identifications of the 266 radio sources detected at 20 cm with the Very Large Array in the Chandra Deep Field South (Kellermann et al. 2008). Using deep i-band Advanced Camera for Surveys, R-band Wide Field Imager, K-band SOFI/NTT, K-band ISAAC/VLT and Spitzer imaging data, we are able to find reliable counterparts for 25

A. Adare

A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at sqrt(s_NN) = 62.4 and 200 GeV, and Cu+Cu collisions sqrt(s_NN) = 22.5, 62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sig

Haim Suchowski, Dan Oron, Ady Arie, Yaron Silberberg

We present a geometrical representation of sum frequency generation process in the undepleted pump approximation. The analogy of such dynamics with the known optical Bloch equations is discussed. We use this analogy to present a novel technique for the achievement of both high efficiency and large bandwidth in a sum frequency conversion processes using adiab

Michio Otsuki, Hisao Hayakawa

The long-time behaviors of the time correlation function $C_η(t)$ of the shear stress for three-dimensional sheared fluids are investigated theoretically. It is found that there are the cross-overs in $C_η(t)$ from $t^{-3/2}$ to $t^{-2}$ for sheared fluids of elastic particles without any thermostat, and from $t^{-3/2}$ to $t^{-5/2}$ for isothermal sheared f

A. Banerjee, Kranti Kumar, P. Chaddah

We show that Pr${_{0.5}}$Ca$_{0.5}$MnO${_3}$ with 2.5% Al substitution and La${_{0.5}}$Ca$_{0.5}$MnO${_3}$ (LCMO) exhibit qualitatively similar and visibly anomalous M-H curves at low temperature. Magnetic field causes a broad first-order but irreversible antiferromagnetic (AF)-insulating (I) to ferromagnetic (FM)-metallic (M) transition in both and gives ri

Adam H. Sobel, Eric D. Maloney, Gilles Bellon, Dargan M. Frierson

The authors argue for the hypothesis that interactive feedbacks involving surface enthalpy fluxes are important to the dynamics of tropical intraseasonal variability. These include cloud-radiative feedbacks as well as surface turbulent flux feedbacks; the former effectively act to transport enthalpy from the ocean to the atmosphere, as do the latter. Evidenc

Marco Battaglia, Nicole Kelley, Benjamin Hooberman

This paper reports the results of a study of the e+e- -> H0A0 process at 1 TeV performed on fully simulated and reconstructed events. The estimated accuracies on the heavy Higgs boson masses, widths and decay branching fractions are discussed in relation to the study of Supersymmetric Dark Matter.

Marco Battaglia, Dario Bisello, Gino Bolla, Daniela Bortoletto

We present results of a study of charged particle track and vertex reconstruction with a beam telescope made of four layers of 50 micron-thin CMOS monolithic pixel sensors using the 120 GeV protons at the FNAL Meson Test Beam Facility. We compare our results to the performance requirements of a future e+e- linear collider in terms of particle track extrapola

B. Marcos

We present the problematic of controlling the discreteness effects in cosmological N-body simulations. We describe a perturbative treatment which gives an approximation describing the evolution under self-gravity of a lattice perturbed from its equilibrium, which allows to trace the evolution of the fully discrete distribution until the time when particles a

Michael Joyce

In cosmology numerical simulations of structure formation are now of central importance, as they are the sole instrument for providing detailed predictions of current cosmological models for a whole class of important constraining observations. These simulations are essentially molecular dynamics simulations of N (>> 1), now up to of order several billion) p

Dominic J. D. Hughes

Linking diagrams with path composition are ubiquitous, for example: Temperley-Lieb and Brauer monoids, Kelly-Laplaza graphs for compact closed categories, and Girard's multiplicative proof nets. We construct the category Link=Span(iRel), where iRel is the category of injective relations (reversed partial functions) and show that the aforementioned linkin

H. Hu, A. Strybulevych, J. H. Page, S. E. Skipetrov

After exactly half a century of Anderson localization, the subject is more alive than ever. Direct observation of Anderson localization of electrons was always hampered by interactions and finite temperatures. Yet, many theoretical breakthroughs were made, highlighted by finite-size scaling, the self-consistent theory and the numerical solution of the Anders

W. Coleman, A. Bernstein, S. Dazeley, R. Svoboda

The possibility of neutron and neutrino detection using water Cerenkov detectors doped with gadolinium holds the promise of constructing very large high-efficiency detectors with wide-ranging application in basic science and national security. This study addressed a major concern regarding the feasibility of such detectors: the transparency of the doped wate

Julia K. Becker, Peter L. Biermann

A correlation between the highest energy Cosmic Rays (above ~ EeV) and the distribution of active galactic nuclei (AGN) gives rise to a prediction of neutrino production in the same sources. In this paper, we present a detailed AGN model, predicting neutrino production near the foot of the jet, where the photon fields from the disk and synchrotron radiation

Jaykov Foukzon

In this paper paraconsistent first-order logic LP^{#}_{\omega} with restricted modus ponens rule and infinite hierarchy levels of contradiction is proposed. Corresponding paraconsistent set theory KSth^{#}_{\omega} is discussed.Axiomatical system HST^{#}_{\omega} as paraconsistent generalization of Hrbacek set theory HST is considered.

Alfonso Artigue, Joaquin Brum, Rafael Potrie

Let $f\colon M\to M$ be an expansive homeomorphism with dense topologically hyperbolic periodic points, $M$ a compact manifold. Then there is a local product structure in an open and dense subset of $M$. Moreover, if some topologically hyperbolic periodic point has codimension one, then this local product structure is uniform. In particular, we conclude that

Zhiwei Yun

We describe several general methods for calculating weights of mixed tilting sheaves. We introduce a notion called "non-cancellation property" which implies a strong uniqueness of mixed tilting sheaves and enables one to calculate their weights effectively. When we have a certain Radon transform, we prove a geometric analogue of Ringel duality which

Wm. G. Hoover, Carol G. Hoover, Janka Petravic

Homogeneous shear flows (with constant strainrate du/dy) are generated with the Doll's and Sllod algorithms and compared to corresponding inhomogeneous boundary-driven flows. We use one-, two-, and three-dimensional smooth-particle weight functions for computing instantaneous spatial averages. The nonlinear stress differences are small, but significant,

Alcides Buss, Ralf Meyer

We define and study square-integrable coactions of locally compact quantum groups on Hilbert modules, generalising previous work for group actions. As special cases, we consider square-integrable Hilbert space corepresentations and integrable coactions on C*-algebras. Our main result is an equivariant generalisation of Kasparov's Stabilisation Theorem.

Z. C. Tu

The maximum power of Feynman's ratchet as a heat engine and the corresponding efficiency ($η_\ast$) are investigated by optimizing both the internal parameter and the external load. When a perfect ratchet device (no heat exchange between the ratchet and the paw via kinetic energy) works between two thermal baths at temperatures $T_1> T_2$, its efficiency

B. Monson, Egon Schulte

The paper studies modular reduction techniques for abstract regular and chiral polytopes, with two purposes in mind: first, to survey the literature about modular reduction in polytopes; and second, to apply modular reduction, with moduli given by primes in Z[t] (with t=\tau the golden ratio), to construct new regular 4-polytopes of hyperbolic types {3,5,3}

François Sausset, Gilles Tarjus, Pascal Viot

We investigate the influence of space curvature, and of the associated "frustration", on the dynamics of a model glassformer: a monatomic liquid on the hyperbolic plane. We find that the system's fragility, i.e. the sensitivity of the relaxation time to temperature changes, increases as one decreases the frustration. As a result, curving space pr

Manuel Bodirsky, Jan Kara

We introduce a new tractable temporal constraint language, which strictly contains the Ord-Horn language of Buerkert and Nebel and the class of AND/OR precedence constraints. The algorithm we present for this language decides whether a given set of constraints is consistent in time that is quadratic in the input size. We also prove that (unlike Ord-Horn) thi

Yasusada Nambu

We investigate quantum entanglement of a scalar field in the inflationary universe. By introducing a bipartite system using a lattice model of scalar field, we apply the separability criterion based on the partial transpose operation and numerically calculate the bipartite entanglement between separate spatial regions. We find that the initial entangled stat

E. P. Kontar, E. Dickson, J. Kasparova

The Ramaty High Energy Solar Spectroscopic Imager (RHESSI) X-ray data base (February 2002 -- May 2006) has been searched to find solar flares with weak thermal components and flat photon spectra. Using a regularised inversion technique, we determine the mean electron flux distribution from count spectra of a selection of events with flat photon spectra in th

Guillaume Burel

In deduction modulo, a theory is not represented by a set of axioms but by a congruence on propositions modulo which the inference rules of standard deductive systems---such as for instance natural deduction---are applied. Therefore, the reasoning that is intrinsic of the theory does not appear in the length of proofs. In general, the congruence is defined t

Robert W. Spekkens, D. H. Buzacott, A. J. Keehn, Ben Toner

In a noncontextual hidden variable model of quantum theory, hidden variables determine the outcomes of every measurement in a manner that is independent of how the measurement is implemented. Using a generalization of this notion to arbitrary operational theories and to preparation procedures, we demonstrate that a particular two-party information-processing

Tetsuya Ito

The relationships between braid ordering and the geometry of its closure is studied. We prove that if an essential closed surface $F$ in the complements of closed braid has relatively small genus with respect to the Dehornoy floor of the braid, $F$ is circular-foliated in a sense of Birman-Menasco's Braid foliation theory. As an application of the result

Ulrich Bunke, Markus Spitzweck, Thomas Schick

The initial motivation of this work was to give a topological interpretation of two-periodic twisted de-Rham cohomology which is generalizable to arbitrary coefficients. To this end we develop a sheaf theory in the context of locally compact topological stacks with emphasis on the construction of the sheaf theory operations in unbounded derived categories, e

Patricia Bouyer, Kim G. Larsen, Nicolas Markey

We consider the model of priced (a.k.a. weighted) timed automata, an extension of timed automata with cost information on both locations and transitions, and we study various model-checking problems for that model based on extensions of classical temporal logics with cost constraints on modalities. We prove that, under the assumption that the model has only

D. D. Bhaktavatsala Rao, P. K. Panigrahi, Chiranjib Mitra

We investigate the effect of common bath decoherence on the qubits of Alice in the usual teleportation protocol. The system bath interaction is studied under the central spin model, where the qubits are coupled to the bath spins through isotropic Heisenberg interaction. We have given a more generalized representation of the protocol in terms of density matri

Jussi M. Kumpula, Mikko Kivela, Kimmo Kaski, Jari Saramaki

In complex network research clique percolation, introduced by Palla et al., is a deterministic community detection method, which allows for overlapping communities and is purely based on local topological properties of a network. Here we present a sequential clique percolation algorithm (SCP) to do fast community detection in weighted and unweighted networks

Anne M. Archibald, Victoria M. Kaspi, Margaret A. Livingstone, Maura A. McLaughlin

The rotation-powered pulsar PSR J1846-0258 in the supernova remnant Kes 75 was recently shown to have exhibited magnetar-like X-ray bursts in mid-2006. Radio emission has not yet been observed from this source, but other magnetar-like sources have exhibited transient radio emission following X-ray bursts. We report on a deep 1.9 GHz radio observation of PSR

Mike Stannett

According to the Church-Turing Thesis (CTT), effective formal behaviours can be simulated by Turing machines; this has naturally led to speculation that physical systems can also be simulated computationally. But is this wider claim true, or do behaviours exist which are strictly hypercomputational? Several idealised computational models are known which sugg

Wei Dai, Youjian, Liu, Brian C. Rider

This paper considers broadcast channels with L antennas at the base station and m single-antenna users, where L and m are typically of the same order. We assume that only partial channel state information is available at the base station through a finite rate feedback. Our key observation is that the optimal number of on-users (users turned on), say s, is a

L. Firlej, B. Kuchta, M. W. Roth, M. J. Connolly

We discuss Molecular Dynamics (MD) computer simulations of tetracosane (C24H50) monolayer physisorbed onto a graphite surface. The alkane molecules are simulated with explicit hydrogens, and the graphite substrate is represented as an all-atom struc-ture having six graphene layers. The tetracosane dynamics modeled in the fully ato-mistic manner agree well wi

D. A. Garanin, E. M. Chudnovsky

We find that dipolar interactions favor ferromagnetic ordering of elongated crystals of Mn12 Acetate below 0.8 K. Ordered crystals must possess domain walls. Motion of the wall corresponds to a moving front of Landau-Zener transitions between quantum spin levels. Structure and mobility of the wall are computed. The effect is robust with respect to inhomogene

Toshifumi Itakura

In this report, we examine the decoherence of a spin qubits system coupled to counted spin chain with a $1/r^2$ interaction by using influence functional. We also examine the time evolution of density matrix numerically when environment is Gaussian noise.

G. D. Anderson, T. Sugawa, M. K. Vamanamurthy, M. Vuorinen

We obtain new inequalities for certain hypergeometric functions. Using these inequalities, we deduce estimates for the hyperbolic metric and the induced distance function on a certain canonical hyperbolic plane domain.

Neven Barisic, Yuan Li, Xudong Zhao, Yong-Chan Cho

The compound HgBa$_2$CuO$_{4+Δ}$ (Hg1201) exhibits a simple tetragonal crystal structure and the highest superconducting transition temperature (T$_c$) among all single Cu-O layer cuprates, with T$_c$ = 97 K (onset) at optimal doping. Due to a lack of sizable single crystals, experimental work on this very attractive system has been significantly limited. Th

Olexei I. Motrunich, Ashvin Vishwanath

Using Monte Carlo simulations, we study a Higgs transition in several three-dimensional lattice realizations of the noncompact CP$^1$ model (NCCP$^1$), a gauge theory with two complex matter fields with SU(2) invariance. By comparing with a one-component theory, which is well understood and has continuous transition in the inverted XY universality class, we

Ari Jokimaki, Harley "Skip" Orr, David G. Russell

A catalog of 232 apparently interacting galaxy pairs of the M51 class is presented. Catalog members were identified from visual inspection of mult-band images in the IRSA archive. The major findings in the compilation of this catalog are (1) A surprisingly low number of the main galaxies in M51 systems are early type spirals and barred spirals. (2) Over 70%

K. Kohno, T. Tosaki, R. Miura, K. Muraoka

We present CO(3-2) emission observations toward the 3'x3' (or 20x20kpc at a distance of 23Mpc) region of the southern barred spiral galaxy NGC 986 using the Atacama Submillimeter Telescope Experiment (ASTE). This effort is a part of our on-going extragalactic CO(3-2) imaging project ADIoS (ASTE Dense gas Imaging of Spiral galaxies). Our CO(3-2) image

Lagogiannis George, Lorentzos Nikos, Sioutas Spyros, Theodoridis Evaggelos

The paper is concerned with the time efficient processing of spatiotemporal predicates, i.e. spatial predicates associated with an exact temporal constraint. A set of such predicates forms a buffer query or a Spatio-temporal Pattern (STP) Query with time. In the more general case of an STP query, the temporal dimension is introduced via the relative order of

Sylvain Chaty

A new type of high-energy binary system has been revealed by the INTEGRAL satellite. These sources are being unveiled by means of multi-wavelength optical, near- and mid-infrared observations. Among these sources, two distinct classes are appearing: the first one is constituted of intrinsically obscured high-energy sources, of which IGR J16318-4848 seems to

Osvaldo Simeone, Oren Somekh, H. Vincent Poor, Shlomo Shamai

A scenario in which a single source communicates with a single destination via a distributed MIMO transceiver is considered. The source operates each of the transmit antennas via finite-capacity links, and likewise the destination is connected to the receiving antennas through capacity-constrained channels. Targeting a nomadic communication scenario, in whic

Li-Li Yu, Wei-Ning Zhang, Cheuk-Yin Wong

In the late stage of the evolution of a pion system in high-energy heavy-ion collisions when pions undergo multiple scatterings, the quantum transport of the interfering pair of identical pions plays an important role in determining the characteristics of the Hanbury-Brown-Twiss (HBT) interference. We study the quantum transport of the interfering pair using

Wen-an Yong

An Onsager-like relation is proposed as a new criterion for constructing and analysing the lattice Boltzmann (LB) method. For LB models obeying the relation, we analyse their linearized stability, establish their diffusive limit, and find new constraints for those with free parameters. The new relation seems of fundamental importance for the LB method.

Takeshi Hirama, Koji Hukushima

On-line learning of a hierarchical learning model is studied by a method from statistical mechanics. In our model a student of a simple perceptron learns from not a true teacher directly, but ensemble teachers who learn from the true teacher with a perceptron learning rule. Since the true teacher and the ensemble teachers are expressed as non-monotonic perce

Anton Bovier, Anton Klimovsky

We study Derrida's generalized random energy model in the presence of uniform external field. We compute the fluctuations of the ground state and of the partition function in the thermodynamic limit for all admissible values of parameters. We find that the fluctuations are described by a hierarchical structure which is obtained by a certain coarse-graini

S. S. Abdullaev, T. Van Rompuy, K. H. Finken, M. Lehnen

An analytical model previously developed to study the structure of the magnetic field for the TEXTOR-DED [S.S. Abdullaev et al. Phys. Plasmas, 6, 153 (1999)] is applied to the similar study of the Ergodic Divertor of Tore Supra tokamak [Ph. Ghendrih, Plasma Phys. Control. Fusion, 38, 1653 (1996)]. The coil configuration of ED Tore Supra consists of six modul

Luca F. Tocchio, Federico Becca, Alberto Parola, Sandro Sorella

We introduce an efficient way to improve the accuracy of projected wave functions, widely used to study the two-dimensional Hubbard model. Taking the clue from the backflow contribution, whose relevance has been emphasized for various interacting systems on the continuum, we consider many-body correlations to construct a suitable approximation for the ground

A. G. Grozin

Recent results and methods of three-loop calculations in HQET are reviewed.

Joerg Baumgartl, Julian Dietrich, Jure Dobnikar, Clemens Bechinger

Digital video-microscopy measurements are reported of both elastic bandstructures and overdamped phonon decay times in two-dimensional colloidal crystals. Both quantities together allow to determine the friction coefficients along various high symmetry directions in q-space. These coefficients contain valuable information on the hydrodynamic forces acting be

Philip J. Marshall, David W. Hogg, Leonidas A. Moustakas, Christopher D. Fassnacht

Lens modeling is the key to successful and meaningful automated strong galaxy-scale gravitational lens detection. We have implemented a lens-modeling "robot" that treats every bright red galaxy (BRG) in a large imaging survey as a potential gravitational lens system. Using a simple model optimized for "typical" galaxy-scale lenses, we generat

Elemer E Rosinger

Semigroups generated by topological operations such as closure, interior or boundary are considered. It is noted that some of these semigroups are in general finite and noncommutative. The problem is formulated whether they are always finite.

Tatsuro Ito, Paul Terwilliger

Let $K$ denote a field and let $V$ denote a vector space over $K$ with finite positive dimension. We consider a pair of linear transformations $A:V \to V$ and $A^*:V \to V$ that satisfy the following conditions: (i) each of $A,A^*$ is diagonalizable; (ii) there exists an ordering $\{V_i\}{i=0}^d$ of the eigenspaces of $A$ such that $A^* V_i \subseteq V_{i-1}

Supratik Mukhopadhyay, Nayana Majumdar

The previously reported neBEM solver has been used to solve electrostatic problems having three-dimensional edges and corners in the physical domain. Both rectangular and triangular elements have been used to discretize the geometries under study. In order to maintain very high level of precision, a library of C functions yielding exact values of potential a

Michael Yu. Kuchiev

Expressions for electric and magnetic charges of dyons, which become massless in the strong-coupling limit of the supersymmetric N=2 gauge theory with an arbitrary gauge group are presented. Transitions into different vacua of the N =1 gauge theory, when the N=2 supersymmetry is broken explicitly to the N =1 case, are discussed. The existence of a minimal se

James P. Gleeson

The motion of overdamped particles in a one-dimensional spatially-periodic potential is considered. The potential is also randomly-fluctuating in time, due to multiplicative colored noise terms, and has a deterministic tilt. Numerical aimulations show two distinct parameter regimes, corresponding to free-running near-deterministic particles, and particles wh

Jan van Neerven, Mark Veraar, Lutz Weis

A detailed theory of stochastic integration in UMD Banach spaces has been developed recently by the authors. The present paper is aimed at giving various sufficient conditions for stochastic integrability.

Kashif Ali, Edy Tri Baskoro, Ioan Tomescu

For given graphs $G$ and $H,$ the \emph{Ramsey number} $R(G,H)$ is the least natural number $n$ such that for every graph $F$ of order $n$ the following condition holds: either $F$ contains $G$ or the complement of $F$ contains $H.$ In this paper, we determine the Ramsey number of paths versus generalized Jahangir graphs. We also derive the Ramsey number $R(

Bijay Kumar Sharma

Phobos is a moon of mars below the synchronous orbit. Because of tidal interaction it is losing its altitude and is launched on a shrinking spiral path of total destruction. Based on planetary-satellite dynamics its rate of loss of altitude is calculated to be twenty meters per century and its doomsday is predicted to be at eleven mega years from now.

Juergen Ott, Tony Wong, Jorge L. Pineda, Annie Hughes

With the ATNF Mopra telescope we are performing a survey in the 12CO(1-0) line to map the molecular gas in the Large Magellanic Cloud (LMC). For some regions we also obtained interferometric maps of the high density gas tracers HCO+ and HCN with the Australia Telescope Compact Array (ATCA). Here we discuss the properties of the elongated molecular complex th

Vincent Moncrief, James Isenberg

We prove that if a stationary, real analytic, asymptotically flat vacuum black hole spacetime of dimension $n\geq 4$ contains a non-degenerate horizon with compact cross sections that are transverse to the stationarity generating Killing vector field then, for each connected component of the black hole's horizon, there is a Killing field which is tangent

Youichi Yanase

The Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) state near the antiferromagnetic quantum critical point (AFQCP) is investigated by analyzing the two dimensional Hubbard model on the basis of the fluctuation exchange (FLEX) approximation. The phase diagram against the magnetic field and temperature is compared with that obtained in the BCS theory. We discuss the i

Aaron J. Roy, Myron Bander

The propagation of charged particles and gauge fields in a compact extra dimension contributes to $g-2$ of the charged particles. In addition, a magnetic flux threading this extra dimension generates an electric dipole moment for these particles. We present constraints on the compactification size and on the possible magnetic flux imposed by the comparison o

Avy Soffer

I show that $H^1$ solutions of the nonlinear Schroedinger equation which are incoming converge to a soliton, in the radial case.

Y. M. Lipkin, E. M. Leibowitz

Photometric observations of V4633 Sgr (Nova Sagittarii 1998) during 1998-2005 reveal the presence of a stable photometric periodicity at P1=180.8 min which is probably the orbital period of the underlying binary system. A second period was present in the light curve of the object for six years. Shortly after the nova eruption it was measured as P2=185.6 min.

Calin Chindris

These are notes on the construction of the GIT-fans for quivers without oriented cycles. We follow closely the steps outlined by N. Ressayre in "The GIT-Equivalence for G-Line Bundles" (Geometriae Dedicata, Volume 81, Numbers 1-3, 2000). A simple construction of the GIT-fan for normal, affine G-varities has been recently given by Ivan V. Arzhantsev a

Calin Chindris

We study the set of all m-tuples $(λ(1),...,λ(m))$ of possible types of finite abelian p-groups $M_{λ(1)}, ..., M_{λ(m)}$ for which there exists a long exact sequence $M_{λ(1)} \to ... \to M_{λ(m)}$. When m=3, we recover Fulton's results on the possible eigenvalues of majorized Hermitian matrices.

Z. Z. Zhang, Kai Chang, K. S. Chan

We investigate theoretically resonant tunneling through double-bended graphene nanoribbon structures, i.e., armchair-edged graphene nanoribbons (AGNRs) in between two semi-infinite zigzag graphene nanoribbon (ZGNR) leads. Our numerical results demonstrate that the resonant tunneling can be tuned dramatically by the Fermi energy and the length and/or widths o

Oren Somekh, Osvalso Simeone, Benjamin M. Zaidel, H. Vincent Poor

The open problem of calculating the limiting spectrum (or its Shannon transform) of increasingly large random Hermitian finite-band matrices is described. In general, these matrices include a finite number of non-zero diagonals around their main diagonal regardless of their size. Two different communication setups which may be modeled using such matrices are

Philip G. Judge, Rebecca Centeno

We examine the hypothesis that ``cool loops'' dominate emission from solar transition region plasma below temperatures of $2\times10^5$K. We compare published VAULT images of H L$α$, a lower transition region line, with near-contemporaneous magnetograms from Kitt Peak, obtained during the second flight (VAULT-2) on 14 June 2002. The measured surface

Gilad Lerman, Jonathan Tyler Whitehouse

We show that high-dimensional analogues of the sine function (more precisely, the d-dimensional polar sine and the d-th root of the d-dimensional hypersine) satisfy a simplex-type inequality in a real pre-Hilbert space H. Adopting the language of Deza and Rosenberg, we say that these d-dimensional sine functions are d-semimetrics. We also establish geometric

Sean M. Dougherty

Space-VLBI observations of stellar sources represent a challenge since there are few sources with sufficiently high brightness temperature for detection on space-ground baselines. X-ray binaries (XRB) are among the few types of stellar radio sources that can be detected. Observations of the unusual X-ray and gamma-ray binary system LS I 61 303 obtained with

John G. Baker, William D. Boggs, Joan Centrella, Bernard J. Kelly

We present a detailed descriptive analysis of the gravitational radiation from black-hole binary mergers of nonspinning black holes, based on numerical simulations of systems varying from equal-mass to a 6:1 mass ratio. Our primary goal is to present relatively complete information about the waveforms, including all the leading multipolar components, to inte