June 2006 arXiv papers — page 13

Boudewijn F. Roukema, Stanislaw Bajtlik

In a multiply connected space, the two twins of the special relativity twin paradox move with constant relative speed and meet a second time without acceleration. The twins' situations appear to be symmetrical despite the need for one to be younger due to time dilation. Here, the suggestion that the apparent symmetry is broken by homotopy classes of the

J. E. Cieza Montalvo, Nelson V. Cortez, J. Sa Borges, Mauro D. Tonasse

Using a peculiar version of the SU(3)L x U(1)N electroweak model, we investigate the production of doubly charged Higgs boson at the Large Hadron Collider. Our results include branching ratio calculations for the doubly charged Higgs and for one of the neutral scalar bosons of the model.

Hong Mao, Nicholas Petropoulos, Song Shu, Wei-Qin Zhao

The effect of finite isospin chemical potential to the effective masses of the mesons at finite temperature is investigated in the framework of the O(4) linear sigma model with explicit chiral symmetry breaking. We present a mechanism to include the isospin chemical potential in the model. By using the Cornwall-Jackiw-Tomboulis method of composite operators,

Hartmut Pecher

Local well-posedness for the Dirac - Klein - Gordon equations is proven in one space dimension, where the Dirac part belongs to H^{-{1/4}+ε} and the Klein - Gordon part to H^{{1/4}-ε} for 0 < ε< 1/4, and global well-posedness, if the Dirac part belongs to the charge class L^2 and the Klein - Gordon part to H^k with 0 < k < 1/2 . The proof uses a null structu

Winfried Zimdahl, Diego Pavon

We demonstrate that a transition from decelerated to accelerated cosmic expansion arises as a pure interaction phenomenon if pressureless dark matter is coupled to holographic dark energy whose infrared cutoff scale is set by the Hubble length. In a spatially flat universe the ratio of the energy densities of both components remains constant through this tra

Michal Dobrski

In this paper we introduce a method for finding a time independent Hamiltonian of a given dynamical system by canonoid transformation. We also find a condition that the system should satisfy to have an equivalent time independent formulation. We study the example of damped oscillator and give the new time independent Hamiltonian for it, which has the propert

D. V. Uvarov

Recently we have considered supertwistor reformulation of the D=4 N=1,2 superstring action that comprises Newman-Penrose dyad components and is classically equivalent to the Green-Schwarz one. It was shown that in the covariant kappa-symmetry gauge the supertwistor representation of the string action simplifies. Here we analyze its Hamiltonian formulation, c

Chong-Sun Chu, George Georgiou, Valentin V. Khoze

Motivated by the recent work of Hofman and Maldacena we construct a classical string solution on the beta-deformed AdS_5 \times \tilde{S}^5 background. This string solution is identified with a magnon state of the integrable spin chain description of the N=1 supersymmetric beta-deformed gauge theory. The string solution carries two angular momenta, an infini

Md. Manirul Ali, A. S. Majumdar, Dipankar Home, Alok Kumar Pan

The quantum analogue of Galileo&#39;s leaning tower experiment is revisited using wave packets evolving under the gravitational potential. We first calculate the position detection probabilities for particles projected upwards against gravity around the classical turning point and also around the point of initial projection, which exhibit mass dependence at

Hong Mao, Ru-Keng Su, Wei-Qin Zhao

The improved quark mass density-dependent model (IQMDD) based on soliton bag model is studied at finite temperature. Appling the finite temperature field theory, the effective potential of the IQMDD model and the bag constant $B(T)$ have been calculated at different temperatures. It is shown that there is a critical temperature $T_{C}\simeq 110 \mathrm{MeV}$

Jerome P. Gauntlett, Oisin A. P. Mac Conamhna, Toni Mateos, Daniel Waldram

For every positively curved Kahler-Einstein manifold in four dimensions we construct an infinite family of supersymmetric solutions of type IIB supergravity. The solutions are warped products of AdS_3 with a compact seven-dimensional manifold and have non-vanishing five-form flux. Via the AdS/CFT correspondence, the solutions are dual to two-dimensional conf

V. P. Konchakovski, M. I. Gorenstein, E. L. Bratkovskaya, H. Stocker

Event-by-event fluctuations of the net baryon number and electric charge in nucleus-nucleus collisions are studied in Pb+Pb at SPS energies within the HSD transport model. We reveal an important role of the fluctuations in the number of target nucleon participants. They strongly influence all measured fluctuations even in the samples of events with rather ri

Niklas Beisert

We propose a phase factor of the worldsheet S-matrix for strings on AdS_5 x S^5 apparently solving Janik&#39;s crossing relation.

A. Balaguera-Antolinez, D. F. Mota, M. Nowakowski

The cosmological constant $Λ$ modifies certain properties of large astrophysical rotating configurations with ellipsoidal geometries, provided the objects are not too compact. Assuming an equilibrium configuration and so using the tensor virial equation with $Λ$ we explore several equilibrium properties of homogeneous rotating ellipsoids. One shows that the

Thomas P. Branson, Doojin Hong

We give explicit formulas for conformally invariant operators with leading term an $m$-th power of Laplacian on the product of spheres with the natural pseudo-Riemannian product metric for all $m$.

A. C. Maggs

We introduce a multiscale Monte Carlo algorithm to simulate dense simple fluids. The probability of an update follows a power law distribution in its length scale. The collective motion of clusters of particles requires generalization of the Metropolis update rule to impose detailed balance. We apply the method to the simulation of a Lennard-Jones fluid and

I. O. Cherednikov, U. D&#39;Alesio, N. I. Kochelev, F. Murgia

We study the Sivers function for valence u and d quarks in the proton within the instanton model for QCD vacuum, adopting the MIT bag model wave functions for quarks. Within approaches based on perturbative one-gluon final state interactions a non-zero value of the Sivers function is related to the presence of both S and P wave components in quark wave funct

Konstantin Glaum, Axel Pelster, Hagen Kleinert, Tilman Pfau

We calculate perturbatively the effect of a dipolar interaction upon the Bose-Einstein condensation temperature. This dipolar shift depends on the angle between the symmetry axes of the trap and the aligned atomic dipole moments, and is extremal for parallel or orthogonal orientations, respectively. The difference of both critical temperatures exhibits most

Dariusz Chruscinski, Andrzej Kossakowski

We construct a class of multipartite states possessing rotational SO(3) symmetry -- these are states of K spin-j_A particles and K spin-j_B particles. The construction of symmetric states follows our two recent papers devoted to unitary and orthogonal multipartite symmetry. We study basic properties of multipartite SO(3) symmetric states: separability criter

R. Chistov

We report the first observation of two charmed strange baryons that decay into $\Lambda_c^+ K^-\pi^+$. The broader of the two states is measured to have a mass of $2978.5\pm 2.1\pm 2.0$ MeV/$c^2$ and a width of $43.5\pm 7.5\pm 7.0$ MeV/$c^2$. The mass and width of the narrow state are measured to be $3076.7\pm 0.9\pm 0.5$ MeV/$c^2$ and $6.2\pm 1.2\pm 0.8$ Me

Pavlos M. Vranas

I demonstrate that the chiral properties of Domain Wall Fermions (DWF) in the large to intermediate lattice spacing regime of QCD, 1 to 2 GeV, are significantly improved by adding to the action two standard Wilson fermions with supercritical mass equal to the negative DWF five dimensional mass. Using quenched DWF simulations I show that the eigenvalue spectr

Kazushi Ueda, Masahito Yamazaki

We discuss the relation between dimer models and coamoebas associated with lattice parallelograms. We also discuss homological mirror symmetry for the product of two projective lines, emphasizing the role of a non-isoradial dimer model.

Ying Zhang

We present an elementary inductive proof which Euler could have obtained, for the corresponding result as the title indicates, had he refined a bit his proof for Fermat&#39;s assertion on representing primes as two squares.

Chi Zhang, Mingsheng Ying

We discuss the problem of designing unambiguous programmable discriminators for any $n$ unknown quantum states in an $m$-dimensional Hilbert space. The discriminator is a fixed measurement which has two kinds of input registers: the program registers and the data register. The program registers consist of the $n$ states, while the data register is prepared a

Joseph Fitzsimons, Li Xiao, Simon C. Benjamin, Jonathan A. Jones

Any technology for quantum information processing (QIP) must embody within it quantum bits (qubits) and maintain control of their key quantum properties of superposition and entanglement. Typical QIP schemes envisage an array of physical systems, such as electrons or nuclei, with each system representing a given qubit. For adequate control, systems must be d

R. de la Madrid

The Bohm-Gadella theory, sometimes referred to as the Time Asymmetric Quantum Theory of Scattering and Decay, is based on the Hardy axiom. The Hardy axiom asserts that the solutions of the Lippmann-Schwinger equation are functionals over spaces of Hardy functions. The preparation-registration arrow of time provides the physical justification for the Hardy ax

Heinz-Peter Breuer

Employing a recently proposed separability criterion we develop analytical lower bounds for the concurrence and for the entanglement of formation of bipartite quantum systems. The separability criterion is based on a nondecomposable positive map which operates on state spaces with even dimension N >= 4, and leads to a class of nondecomposable optimal entangl

A. Raczynski, J. Zaremba, S. Zielinska-Kaniasty

Storing and release of a quantum light pulse in a medium of atoms in the tripod configuration are studied. Two complementary sets of control fields are defined, which lead to independent and complete photon release at two stages. The system constitutes a new kind of a flexible beam splitter in which the input and output ports concern photons of the same dire

L. Derkacz, L. Jakobczyk

We consider a pair of three-level atoms interacting with the vacuum. The process of disentanglement due to spontaneous emission and the role of quantum interference between principal transitions in this process, are analysed. We show that the presence of interference can slow down disentanglement. In the limit of maximal interference, some part of initial en

S. Eh. Shirmovsky

Description of time evolution of the relativistic unstable electromagnetic system consisting of Fermi-Dirac particle interacting with electromagnetic field, in the framework of the Liouville space extension of quantum mechanics is done. The work was carried out on the basis of Prigogine&#39;s unified formulation of quantum and kinetic dynamics. The eigenvalu

Maria A. Avino-Diaz, Oscar Moreno

We describe here the new concept of $ε$-Homomorphisms of Probabilistic Regulatory Gene Networks(PRN). The $ε$-homomorphisms are special mappings between two probabilistic networks, that consider the algebraic action of the iteration of functions and the probabilistic dynamic of the two networks. It is proved here that the class of PRN, together with the homo

A. Bhattacharyay, A. Trovato, F. Seno

We formulate a simple solvation potential based on a coarsed-grain representation of amino acids with two spheres modeling the $C_α$ atom and an effective side-chain centroid. The potential relies on a new method for estimating the buried area of residues, based on counting the effective number of burying neighbours in a suitable way. This latter quantity sh

Sergio Godoy Penteado, Claudio S. Meneses, Anderson de Oliveira Lobo, Airton Abrahao Martin

The biochemical changes on normal and degenerated tissues of rotator cuff supraspinatus tendons were probed by FT-Raman spectroscopy. The Raman spectra showed differences on the spectral regions of cysteine, amino acids, nucleic acids, carbohydrates, and lipids. These spectral differences were assigned to pathological biochemical alterations due to the degen

Santiago Schnell, Santo Fortunato, Sourav Roy

In protein-protein interaction networks certain topological properties appear to be recurrent: networks maps are considered scale-free. It is possible that this topology is reflected in the protein structure. In this paper we investigate the role of protein disorder in the network topology. We find that the disorder of a protein (or of its neighbors) is inde

Miguel Levy, Rong Li

Inter-modal coupling in photonic bandgap optical channels in magnetic films is used to leverage the transverse-electric (TE) to transverse-magnetic (TM) mode conversion due to the Faraday Effect. The underlying mechanism is traced to the dependence of the grating coupling-constant on the modal refractive index and the mode profile of the propagating beam, a

Masato Ida, Nobuyuki Oshima

The Gaussian-filtered Navier-Stokes equations are examined theoretically and a generalized theory of their numerical stability is proposed. Using the exact expansion series of subfilter-scale stresses or integration by parts, the terms describing the interaction between the mean and fluctuation portions in a statistically steady state are theoretically rewri

W. Meissl, M. C. Simon, J. R. Crespo Lopez-Urrutia, H. Tawara

A novel technique to identify small fluxes of mixed highly charged ion beams extracted from an Electron Beam Ion Trap (EBIT) is presented and practically demonstrated. The method exploits projectile charge state dependent potential emission of electrons as induced by ion impact on a metal surface to separate ions with identical or very similar mass-to-charge

ATF2 Group

The two major goals for this facility, called ATF2, are : (A) Achievement of a 37 nm beam size, and (B) control of beam position down to 2 nm level. The scientific justification for the ATF2 project and its technical design have been described in Volume 1 of the ATF2 Proposal. We present here Volume 2 of the ATF2 Proposal, in which we present specifics of th

Avner Peleg, Jerome V. Moloney

We study propagation of two lowest order Gaussian laser beams with different wavelengths in weak atmospheric turbulence. Using the Rytov approximation and assuming a slow detector we calculate the longitudinal and radial components of the scintillation index for a typical free space laser communication setup. We find the optimal configuration of the two lase

I. Brida, F. M. Nunes, B. A. Brown

11Li is studied within a three-body model 9Li+n+n where the core is allowed to be deformed and/or excite. In particular, we include reorientation couplings and couplings between the two bound states of 9Li. Contrary to the other examples studied within this model, we find that core excitation does not affect the structure of 11Li significantly. Reorientation

Patrick Achenbach

For the first time, lead fluoride is used as a fast and compact material in electromagnetic calorimetry. Excellent optical and mechanical properties of the pure Cherenkov crystals are necessary for the A4 collaboration to perform a measurement of the nucleon&#39;s strange form factors. Visible scattering and absorption centers as well as surface damages have

F. Gungor, O. Aykanat

We compute the Lie symmetry algebra of the generalized Davey-Stewartson (GDS) equations and show that under certain conditions imposed on parameters in the system it is infinite-dimensional and isomorphic to that of the standard integrable Davey-Stewartson equations which is known to have a very specific Kac-Moody-Virasoro loop algebra structure. We discuss

Adrian Ioana

We consider II$_1$ factors of the form $M=\bar{\bigotimes}_{G}N\rtimes G$, where either i) $N$ is a non-hyperfinite II$_1$ factor and $G$ is an ICC amenable group or ii) $N$ is a weakly rigid II$_1$ factor and $G$ is ICC group and where $G$ acts on $\bar{\bigotimes}_{G}N$ by Bernoulli shifts. We prove that isomorphism of two such factors implies cocycle conj

Ernesto Lupercio, Bernardo Uribe, Miguel A. Xicoténcatl

By using the loop orbifold of the symmetric product, we give a formula for the Poincaré polynomial of the free loop space of the Borel construction of the symmetric product. We also show that the Chas-Sullivan product structure in the homology of the free loop space of the Borel construction of the symmetric product induces a ring structure in the homology o

Walter Ferrer Santos, Mariana Haim

In a biFrobenius algebra H, in particular in the case that H is a finite dimensional Hopf algebra, the antipode S can be decomposed as S= cf where c and f are the Frobenius and coFrobenius isomorphisms. We use this decomposition to present an easy proof of Radford&#39;s formula for the fourth composition power of S. Then, in the case that the map S is the co

D. B. McReynolds

This thesis investigates cusp cross-sections of arithmetic real, complex, and quaternionic hyperbolic $n$--orbifolds. We give a smooth classification of these submanifolds and analyze their induced geometry. One of the primary tools is a new subgroup separability result for general arithmetic lattices.

Irina Nenciu

We find a finite CMV matrix whose eigenvalues coincide with the Dirichlet data of a circular periodic problem. As a consequence, we obtain circular analogues of the classical trace formulae for periodic Jacobi matrices.

Olivia Gutu, Jesus A. Jaramillo

For a large class of metric spaces with nice local structure, which includes Banach-Finsler manifolds and geodesic spaces of curvature bounded above, we give sufficient conditions for a local homeomorphism to be a covering projection. We first obtain a general condition in terms of a path continuation property. As a consequence, we deduce several conditions

A. V. Kitaev

We consider a linear $2\times2$ matrix ODE with two coalescing regular singularities. This coalescence is restricted with an isomonodromy condition with respect to the distance between the merging singularities in a way consistent with the ODE. In particular, a zero-distance limit for the ODE exists. The monodromy group of the limiting ODE is calculated in t

Julia Weber

For discrete groups G, we introduce equivariant Nielsen invariants. They are equivariant analogs of the Nielsen number and give lower bounds for the number of fixed point orbits in the G-homotopy class of an equivariant endomorphism f:X->X. Under mild hypotheses, these lower bounds are sharp. We use the equivariant Nielsen invariants to show that a G-equivar

Julia Weber

We define equivariant homology theories using bordism of stratifolds with a G-action, where G is a discrete group. Stratifolds are a generalization of smooth manifolds which were introduced by Kreck. He defines homology theories using bordism of suitable stratifolds. We develop the equivariant generalization of these ideas.

Julia Weber

We geometrically construct a homology theory that generalizes the Euler characteristic mod 2 to objects in the unoriented cobordism ring N_*(X) of a topological space X. This homology theory Eh_* has coefficients Z/2 in every nonnegative dimension. There exists a natural transformation N_*(X)->Eh_*(X) that for X=pt assigns to each smooth manifold its Euler c

David R. Bickel

The main question concerns another recent advance in sequential Monte Carlo, the use of a mixture transition kernel that automatically adapts to the target distribution (Douc et al. 2006). Is there a class of static inference problems for which the backward-kernel approach is better suited, or is it too early to predict which method may have better performan

P. Mathonet, F. Radoux

In this paper, we analyse the question of existence of a natural and projectively equivariant symbol calculus, using the theory of projective Cartan connections. We establish a close relationship between the existence of such a natural symbol calculus and the existence of an \sl(m+1,\R)-equivariant calculus over \R^{m} in the sense of [15,1]. Moreover we sho

P. Mathonet, F. Radoux

The existence of a natural and projectively equivariant quantization in the sense of Lecomte [20] was proved recently by M. Bordemann [4], using the framework of Thomas-Whitehead connections. We give a new proof of existence using the notion of Cartan projective connections and we obtain an explicit formula in terms of these connections. Our method yields th

Dmitry Tamarkin

We introduce a homotopy 2-category structure on the category of 2-categories.

Michael Cwikel, Svante Janson

If (A_0,A_1) and (B_0,B_1) are Banach couples and a linear operator T from A_0 + A_1 to B_0 + B_1 maps A_0 compactly into B_0 and maps A_1 boundedly into B_1, does T necessarily also map [A_0,A_1]_s compactly into [B_0,B_1]_s for s in (0,1)? After 42 years this question is still not answered, not even in the case where T is also compact from A_1 to B_1. But

Zhiliang Ying, Cun-Hui Zhang

Yuan Shih Chow was born in Hubei province in China, on September 1, 1924. The eldest child of a local militia and political leader, he grew up in war and turmoil. His hometown was on the front line during most of the Japanese invasion and occupation of China. When he was 16, Y. S. Chow journeyed, mostly on foot, to Chongqing (Chung-King), the wartime Chinese

Fabian Radoux

In [3], the authors showed the existence and the uniqueness of a sl(m+1,\R)-equivariant quantization in the non-critical situations. The curved generalization of the sl(m+1,\R)-equivariant quantization is the natural and projectively equivariant quantization. In [1] and [7], the existence of such a quantization was proved in two different ways. In this paper

Andrei Caldararu

We argue that the existence of genus one fibrations with multisections of high degree on certain Calabi-Yau threefolds implies the existence of pairs of such varieties that are not birational, but are derived equivalent. It also (likely) implies the existence of non-birational counterexamples to the Torelli problem for Calabi-Yau threefolds.

Thorsten Holm, Wolfgang Willems

Recently, a new conjecture on the degrees of the irreducible Brauer characters of a finite group was presented by the second author. In this paper we propose a &#39;local&#39; version of this conjecture for blocks B of finite groups, giving a lower bound for the maximal degree of an irreducible Brauer character belonging to B in terms of the dimension of B a

Lewis Bowen

This paper is being withdrawn because an error was discovered in lemma 4.3. Although the rest of the paper appears to be correct, this error invalidates the proof of theorem 3.1 and theorem 3.3.

Diego Chialva, Thibault Damour

We study the gravitational emission, in Superstring Theory, from fundamental strings exhibiting cusps. The classical computation of the gravitational radiation signal from cuspy strings features strong bursts in the special null directions associated to the cusps. We perform a quantum computation of the gravitational radiation signal from a cuspy string, as

Govind S. Krishnaswami

Large-N multi-matrix loop equations are formulated as quadratic difference equations in concatenation of gluon correlations. Though non-linear, they involve highest rank correlations linearly. They are underdetermined in many cases. Additional linear equations for gluon correlations, associated to symmetries of action and measure are found. Loop equations ar

Aninda Sinha, Nemani V. Suryanarayana

We investigate the inclusion of 10-dimensional string loop corrections to the entropy function of two-charge extremal small black holes of the heterotic string theory compactified on S^1 x T^5 and show that the entropy is given by \pi\sqrt{a q_1 q_2+b q_1} where q_1 and q_2 are the charges with q_1 >> q_2 >> 1 and a and b are constants. Incorporating certain

Oren Bergman, Gilad Lifschytz

We analyze the possible configurations of D-branes breaking on other D-branes. We describe these configurations in the context of a brane-antibrane effective theory in two ways. First as a tachyon configuration representing a non-trivial bundle over the sphere surrounding the end of the brane a la Polchinski, and second in terms of tachyon solitons using hom

A. V. Smirnov, V. A. Smirnov

We suggest a mathematical definition of the notion of master integrals and present a brief review of algorithmic methods to solve reduction problems for Feynman integrals based on integration by parts relations. In particular, we discuss a recently suggested reduction algorithm which uses Groebner bases. New results obtained with its help for a family of thr

R. S. Thorne, A. D. Martin, W. J. Stirling

We present the new preliminary MRST parton distributions at NLO and NNLO. The analysis includes some new data and there is an improvement in the theoretical treatment at NNLO. Essentially complete NNLO partons are presented for the first time, together with uncertainties.

R. Casalbuoni, M. Ciminale, R. Gatto, G. Nardulli

We study in the Ginzburg-Landau approximation, the Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase of QCD with three flavors and one plane wave, including terms of order O(1/mu). We show that the LOFF window is slightly enlarged, and actually splits into two different regions, one characterized by u-s and d-u pairings and the other with d-u pairs only.

Ilja Dorsner

We present phenomenological aspects of the simplest realistic SU(5) grand unified theory--the theory with the 5, 15, and 24 dimensional representations in the Higgs sector. We show that a successful gauge coupling unification sets experimentally accessible upper bound on the total proton decay lifetime. It also relates proton decay lifetime to scalar leptoqu

Sergey Alekhin, Kirill Melnikov, Frank Petriello

We discuss the influence of fixed target Drell-Yan data on the extraction of parton distribution functions at next-to-next-to-leading order (NNLO) in QCD. When used in a parton distribution fit, the Drell-Yan (DY) data constrain sea quark distributions at large values of Bjorken x. We find that not all available DY data are useful for improving the precision

Gabriele Benelli

We present several alternative techniques used by the BaBar Collaboration in order to measure the Unitarity Triangle angle gamma. We also present the results of two searches designed to improve the measurements of sin(2beta) using penguin B decay modes by reducing the hadronic corrections uncertainties.

Aharon Davidson, Ilya Gurwich

Following Dirac&#39;s brane variation prescription, the brane must not be deformed during the variation process, or else the linearity of the variation may be lost. Alternatively, the variation of the brane is done, in a special Dirac frame, by varying the bulk coordinate system itself. Imposing appropriate Dirac style boundary conditions on the constrained

Alexander Burinskii

On the basis of the Kerr spinning particle, we show that the mass renormalization is perfectly performed by gravity for an arbitrary distribution of source matter. A smooth regularization of the Kerr-Newman solution is considered, leading to a source in the form of a rotating bag filled by a false vacuum. It is shown that gravity controls the phase transitio

Mohammad A. Maddah-Ali, Amin Mobasher, Amir Kayvan Khandani

For a wide class of multi-user systems, a subset of capacity region which includes the corner points and the sum-capacity facet has a special structure known as polymatroid. Multiaccess channels with fixed input distributions and multiple-antenna broadcast channels are examples of such systems. Any interior point of the sum-capacity facet can be achieved by

Jeff M. Phillips, Ran Liu, Carlo Tomasi

We describe a variation of the iterative closest point (ICP) algorithm for aligning two point sets under a set of transformations. Our algorithm is superior to previous algorithms because (1) in determining the optimal alignment, it identifies and discards likely outliers in a statistically robust manner, and (2) it is guaranteed to converge to a locally opt

Lea Cyrus

This paper describes an interdisciplinary approach which brings together the fields of corpus linguistics and translation studies. It presents ongoing work on the creation of a corpus resource in which translation shifts are explicitly annotated. Translation shifts denote departures from formal correspondence between source and target text, i.e. deviations t

Jean Krivine

A verification method for distributed systems based on decoupling forward and backward behaviour is proposed. This method uses an event structure based algorithm that, given a CCS process, constructs its causal compression relative to a choice of observable actions. Verifying the original process equipped with distributed backtracking on non-observable actio

Wim Martens, Frank Neven, Marc Gyssens

Typechecking consists of statically verifying whether the output of an XML transformation always conforms to an output type for documents satisfying a given input type. In this general setting, both the input and output schema as well as the transformation are part of the input for the problem. However, scenarios where the input or output schema can be consi

Vladimir Vovk

Prediction is a complex notion, and different predictors (such as people, computer programs, and probabilistic theories) can pursue very different goals. In this paper I will review some popular kinds of prediction and argue that the theory of competitive on-line learning can benefit from the kinds of prediction that are now foreign to it.

Ralf Laemmel

The textbook by Doets and van Eijck puts the Haskell programming language systematically to work for presenting a major piece of logic and mathematics. The reader is taken through chapters on basic logic, proof recipes, sets and lists, relations and functions, recursion and co-recursion, the number systems, polynomials and power series, ending with Cantor&#3

Binquan Luan, Mark O. Robbins

Atomistic simulations are used to test the equations of continuum contact mechanics in nanometer scale contacts. Nominally spherical tips, made by bending crystals or cutting crystalline or amorphous solids, are pressed into a flat, elastic substrate. The normal displacement, contact radius, stress distribution, friction and lateral stiffness are examined as

Christof Teuscher

Nanoscale electronics and novel fabrication technologies bear unique opportunities for self-assembling multi-billion component systems in a largely random manner, which would likely lower fabrication costs significantly compared to a definite ad hoc assembly. It has been shown that communication networks with the small-world property have major advantages in

Devis Bellucci, Massimo Rontani, Guido Goldoni, Elisa Molinari

We investigate the stability of few-electron quantum phases in vertically coupled quantum dots under a magnetic field of arbitrary strength and direction. The orbital and spin stability diagrams of realistic devices containing up to five electrons, from strong to weak inter-dot coupling, is determined. Correlation effects and realistic sample geometries are

R. L. C. Vink, H. H. Wensink

We demonstrate that the law of the rectilinear coexistence diameter in two-dimensional (2D) mixtures of non-spherical colloids and non-adsorbing polymers is violated. Upon approach of the critical point, the diameter shows logarithmic singular behavior governed by a term t ln(t), with t the relative distance from the critical point. No sign of a term t^2b co

Salvatore Torquato

A fascinating inverse problem that has been receiving considerable attention is the construction of realizations of random two-phase heterogeneous media with a target two-point correlation function. However, not every hypothetical two-point correlation function corresponds to a realizable two-phase medium. Here we collect all of the known necessary condition

A. Agliolo Gallitto, G. Bonsignore, G. Giunchi, M. Li Vigni

We report experimental results of second-harmonic (SH) response at microwave frequency in several ceramic MgB2 samples, prepared by different methods. The SH signal has been investigated as a function of the temperature and DC magnetic field. The investigation has been carried out at low magnetic fields, where nonlinear processes arising from motion of Abrik

M. T. Escote, V. B. Barbeta, R. F. Jardim, J. Campo

Polycrystalline Nd$_{1-x}$Eu$_{x}$NiO$_3$ ($0 \leq x \leq 0.5$) compounds were synthesized in order to investigate the character of the metal-insulator (MI) phase transition in this series. Samples were prepared through the sol-gel route and subjected to heat treatments at $\sim$1000 $^\circ$C under oxygen pressures as high as 80 bar. X-ray Diffraction (XRD)

Yatendra S. Jain

Macro-orbital representation of a particle (detailed account given in cond-mat/0603784) has been used to develop the microscopic theory of a system of interacting bosons. It concludes that: (i) below certain temperature (say, $T_λ$), particles assume a state of (q, -q) bound pairs, (ii) the $λ-$transition is a consequence of inter-particle quantum correlatio

N. D. Zhigadlo, J. Karpinski

Ca2-xNaxCuO2Cl2 is a structural analogue to the La2-xSrxCuO4 superconductor. By substituting Na+ for Ca2+ mobile holes are introduced into the CuO2 planes. A series of experiments shows that the Na content x depends not only on the pressure during synthesis but also on the synthesis temperature and time. Ca2-xNaxCuO2Cl2 crystals (x=0.10 and Tc,on=13.5 K) up

Prasenjit Sen

We have studied Peierls instability in an atomically thin wire of sodium atoms using first-principles density-functional methods. A Na wire has a stable uniform linear structure over a range of inter-atomic distances. At smaller inter-atomic distances it develops a zigzag distortion. At larger inter-atomic distances, just before breaking, a Na wire undergoes

G. M. Minkov, A. V. Germanenko, O. E. Rut, A. A. Sherstobitov

Temperature and magnetic field dependences of the conductivity in heavily doped, strongly disordered two-dimensional quantum well structures GaAs/In$_x$Ga$_{1-x}$As/GaAs are investigated within wide conductivity and temperature ranges. Role of the interference in the electron transport is studied in the regimes when the phase breaking length $L_ϕ$ crosses ov

P. Y. Song, J. F. Wang, C. P. Chen, H. Deng

Unusually large low field magetoresistance (LFMR), ~ 10 %, at 300 K has been observed with the sample of mono-dispersed Fe3O4 magnetite nanospheres, ~ 200 nm, compactly cold-pressed and sintered at 800 C. A detailed analysis on the transport and magnetic measurements indicates that the electron conduction is dominated by the spin-dependent scattering or tunn

Kaicheng Zhang, Li-li Ding, Cheng-gang Zhuang, Li-ping Chen

We have successfully deposited thick MgB2 film on the (0001) crystalline surface of sapphire by the method of hybrid physical-chemical vapor deposition (HPCVD). The film thickness is about 1.3 micron. It has a dense and interlaced structure. The film surface, shown by SEM, is stacked with MgB2 microcrystals. Transport measurements by the 4-probe technique ha

Mariusz P. Dabrowski

Following the observational evidence for cosmic acceleration which may exclude a possibility for the universe to recollapse to a second singularity, we review alternative scenarios of its future evolution. Although the de Sitter asymptotic state is still an option, some other asymptotic states which allow new types of singularities such as Big-Rip (due to a

Jason X. Prochaska, John M. O&#39;Meara, Stephane Herbert-Fort, Scott Burles

We present abundance measurements for two super Lyman Limit systems (SLLS; quasar absorption line systems with 10^19 cm^-2 < N_HI < 10^20.3 cm^-2) selected from a set of metal-strong absorbers in the Sloan Digital Sky Survey quasar database. After applying estimate corrections for photoionization effects, we derive gas-phase metallicities of [M/H]=+0.7 +/- 0

Joshua D. Simon, Francisco Prada, Jose M. Vilchez, Leo Blitz

We show that there are strong local correlations between metallicity, surface brightness, and dynamical mass-to-light ratio within M33, analogous to the fundamental line of dwarf galaxies identified by Prada & Burkert (2002). Using near-infrared imaging from 2MASS, the published rotation curve of M33, and literature measurements of the metallicities of HII r

Enwei Liang, Bing Zhang, Bin-Bin Zhang, Z. G. Dai

It is long speculated that long duration gamma-ray bursts (GRBs) originate froma relativistic jet emerging from a collapsing massive star progenitor. Although associations of core-collapsing supernovae with long GRB afterglows have been identified in a number of systems, including the latest X-ray flash (XRF) 060218/SN 2006aj connection detected by Swift, di

T. Bergmann, R. Engel, D. Heck, N. N. Kalmykov

An efficient scheme for one-dimensional extensive air shower simulation and its implementation in the program CONEX are presented. Explicit Monte Carlo simulation of the high-energy part of hadronic and electromagnetic cascades in the atmosphere is combined with a numeric solution of cascade equations for smaller energy sub-showers to obtain accurate shower

M. Werner, G. Fazio, G. Rieke, T. Roellig

This article provides a brief overview of the Spitzer Space Telescope and discusses its initial scientific results on galactic and solar system science.