April 2006 arXiv papers — page 15

Rodrigo de Miguel, Ori Shental, Ralf R. Muller, Ido Kanter

Rodrigo de Miguel et al 2007 J. Phys. A: Math. Theor. 40 5241-5260: A noisy vector channel operating under a strict complexity constraint at the receiver is introduced. According to this constraint, detected bits, obtained by performing hard decisions directly on the channel's matched filter output, must be the same as the transmitted binary inputs. An a

Oleg Lunin

We study solutions of Type IIB supergravity, which describe the geometries dual to supersymmetric Wilson lines in N=4 super-Yang-Mills. We show that the solutions are uniquely specified by one function which satisfies a Laplace equation in two dimensions. We show that if this function obeys a certain Dirichlet boundary condition, the corresponding geometry i

J. Uffink, M. Seevinck

We strengthen the bound on the correlations of two spin-1/2 particles (qubits) in separable (non-entangled) states for locally orthogonal spin directions by much tighter bounds than the well-known Bell inequality. This provides a sharper criterion for the experimental distinction between entangled and separable states, and even one which is a necessary and s

Muthiah Annamalai, Hemant Kumar, Leela Velusamy

This paper discusses the problems faced with interoperability between two programming languages, with respect to GNU Octave, and GTK API written in C, to provide the GTK API on Octave.Octave-GTK is the fusion of two different API's: one exported by GNU Octave [scientific computing tool] and the other GTK [GUI toolkit]; this enables one to use GTK primiti

Sarah Mason

We exhibit a weight-preserving bijection between semi-standard Young tableaux and semi-skyline augmented fillings to provide a combinatorial proof that the Schur functions decompose into nonsymmetric functions indexed by compositions. The insertion procedure involved in the proof leads to an analogue of the Robinson-Schensted-Knuth Algorithm for semi-skyline

Ivan Saika-Voivod, Louis Poon, Richard K. Bowles

The free energy of a 600-atom Lennard-Jones cluster is calculated as a function of surface and bulk crystallinity in order to study the structural transformations that occur in the core of medium sized clusters. Within the order parameter range studied, we find the existence of two free energy minima at temperatures near freezing. One minimum, at low values

John Cardy

We use Coulomb gas methods to propose an explicit form for the scaling limit of the partition function of the critical O(n) model on an annulus, with free boundary conditions, as a function of its modulus. This correctly takes into account the magnetic charge asymmetry and the decoupling of the null states. It agrees with an earlier conjecture based on Bethe

Thomas DeGrand, Stefan Schaefer

We present a set of related Hybrid Monte Carlo methods to simulate an arbitrary number of dynamical overlap fermions. Each fermion is represented by a chiral pseudo-fermion field. The new algorithm reduces critical slowing down in the chiral limit and for sectors of nontrivial topology.

G. Barro Calvo, A. L. Maroto

We confront the predictions of different quintessence models with recent measurements of the luminosity distance from two sets of supernovae type Ia. In particular, we consider the 157 SNe Ia in the Gold dataset with z<1.7, and the more recent data containing 71 supernovae obtained by the Supernova Legacy Survey (SNLS) with z<1. We numerically solve the evol

F. Finelli, G. Marozzi, G. P. Vacca, G. Venturi

The evolution of gauge invariant second-order scalar perturbations in a general single field inflationary scenario are presented. Different second order gauge invariant expressions for the curvature are considered. We evaluate perturbatively one of these second order curvature fluctuations and a second order gauge invariant scalar field fluctuation during th

E. Puddu, A. Andreoni, I. P. Degiovanni, M. Bondani

We present the first experimental demonstration of ghost imaging realized with intense beams generated by a parametric downconversion interaction seeded with pseudo-thermal light. As expected, the real image of the object is reconstructed satisfying the thin-lens equation. We show that the experimental visibility of the reconstructed image is in accordance w

Laura Fontanelli, Paolo Lorenzoni, Marco Pedroni

We introduce a bi-Hamiltonian hierarchy on the loop-algebra of sl(2) endowed with a suitable Poisson pair. It gives rise to the usual CH hierarchy by means of a bi-Hamiltonian reduction, and its first nontrivial flow provides a 3-component extension of the CH equation.

Ilya Kuprov

This study explores, both theoretically and experimentally, the photochemically induced dynamic nuclear polarization (photo-CIDNP) of 19F nuclei, the associated spin relaxation, cross-relaxation and cross-correlation effects, as well as potential applications of 19F CIDNP to protein structure and folding problems. Keywords: CIDNP, relaxation, fluorine, NMR,

C. Farrell, A. H. Hoang

We determine the next-to-leading logarithmic (NLL) QCD corrections to the cross section sigma(e+e- to t bar t H) for center-of-mass energies up to 500 GeV. The dynamics is dominated by nonrelativistic effects, and the summation of terms singular in the relative t bar t velocity is mandatory to all orders in the strong coupling constant alpha_s using an effec

Silvio Franz, Giorgio Parisi

We study the behavior of one dimensional Kac spin glasses as function of the interaction range. We verify by Montecarlo numerical simulations the crossover from local mean field behavior to global paramagnetism. We investigate the behavior of correlations and find that in the low temperature phase correlations grow at a faster rate then the interaction range

F. Fuchs, J. Furthmüller, F. Bechstedt, M. Shishkin

We present a comparative full-potential study of generalized Kohn-Sham schemes (gKS) with explicit focus on their suitability as starting point for the solution of the quasiparticle equation. We compare $G_0W_0$ quasiparticle band structures calculated upon LDA, sX, HSE03, PBE0, and HF functionals for exchange and correlation (XC) for Si, InN and ZnO. Furthe

J. Fernandez-Rossier, R. Aguado

We study a single electron transistor (SET) based upon a II-VI semiconductor quantum dot doped with a single Mn ion. We present evidence that this system behaves like a quantum nanomagnet whose total spin and magnetic anisotropy depend dramatically both on the number of carriers and their orbital nature. Thereby, the magnetic properties of the nanomagnet can

Lars Fromme, Stephan J. Huber

In non-supersymmetric models of electroweak baryogenesis the top quark plays a crucial role. Its CP-violating source term can be calculated in the WKB approximation. We point out how to resolve certain discrepancies between computations starting from the Dirac equation and the Schwinger--Keldysh formalism. We also improve on the transport equations, keeping

K. Janzen, V. Meden, K. Schoenhammer

We investigate how the conductance G through a clean interacting quantum wire is affected by the presence of contacts and noninteracting leads. The contacts are defined by a vanishing two-particle interaction to the left and a finite repulsive interaction to the right or vice versa. No additional single-particle scattering terms (impurities) are added. We fi

Joost Vercruysse

We show the close connection between appearingly different Galois theories for comodules introduced recently in [J. Gómez-Torrecillas and J. Vercruysse, Comatrix corings and Galois Comodules over firm rings, arXiv:math.RA/0509106.] and [R. Wisbauer, On Galois comodules (2004), to appear in Comm. Algebra.]. Furthermore we study equivalences between categories

D. Djukanovic, J. Gegelia, S. Scherer

Using the examples of pion-nucleon scattering and the nucleon mass we analyze the convergence of perturbative series in the framework of baryon chiral perturbation theory. For both cases we sum up sets of an infinite number of diagrams by solving equations exactly and compare the solutions with the perturbative contributions.

James S. Graber

We investigate the possibility of using binary IMBH inspirals to perform the Ryan test of general relativity in a theoretically robust manner using data from early in the detectable part of the inspiral. We find this to be feasible and compute the masses of the most favourable systems.

D. Panigrahi, Y. Z. Zhang, S. Chatterjee

Homogeneous cosmological solutions are obtained in five dimensional space time assuming equations of state $ p = kρ$ and $ p_{5}= γρ$ where p is the isotropic 3 - pressure and $p_{5}$, that for the fifth dimension. Using different values for the constants k and $γ$ many known solutions are rediscovered. Further the current acceleration of the universe has le

Junjie Cao, Gad Eilam, Ken-ichi Hikasa, Jin Min Yang

We examine experimental constraints on scharm-stop flavor mixing in the minimal supersymmetric standard model, which arise from the experimental bounds on squark and Higgs boson masses, the precision measurements of W-boson mass and the effective weak mixing angle, as well as the experimental data on B_s-\bar B_s mixing and b -> s gamma. We find that the com

S. Rai Choudhury, A. S. Cornell, Naveen Gaur, Ashok Goyal

Though the predictions of the Standard Model (SM) are in excellent agreement with experiments there are still several theoretical problems, such as fine-tuning and the hierarchy problem. These problems are associated with the Higgs sector of the SM, where it is widely believed that some {\it ``new physics&#34;} will take over at the TeV scale. One beyond the

Alexander Mitov, Sven-Olaf Moch

We report on the analytic calculation of the second-order QCD corrections to semi-inclusive hadron production in electron-positron annihilation. The calculation of the single-particle inclusive cross-section in time-like kinematics is performed in Mellin N-space and uses an algorithmic evaluation of inclusive phase-space integrals, based on the unitarity cut

B. Nikolic, B. Sazdovic

It is known that the presence of antisymmetric background field $B_{μν}$ leads to noncommutativity of Dp-brane manifold. Addition of the linear dilaton field in the form $Φ(x)=Φ_0+a_μx^μ$, causes the appearance of the commutative Dp-brane coordinate $x=a_μx^μ$. In the present article we show that for some particular choices of the background fields, $a^2\equ

Harry Buhrman, Richard Cleve, Monique Laurent, Noah Linden

We show that quantum circuits cannot be made fault-tolerant against a depolarizing noise level of approximately 45%, thereby improving on a previous bound of 50% (due to Razborov). Our precise quantum circuit model enables perfect gates from the Clifford group (CNOT, Hadamard, S, X, Y, Z) and arbitrary additional one-qubit gates that are subject to that much

R. Gutierrez, S. Mohapatra, H. Cohen, D. Porath

We investigate quantum transport characteristics of a ladder model, which effectively mimics the topology of a double-stranded DNA molecule. We consider the interaction of tunneling charges with a selected internal vibrational degree of freedom and discuss its influence on the structure of the current-voltage characteristics. Further, molecule-electrode cont

T. Burns, F. E. Close

Flux tube model predictions for hybrid meson decays are beginning to be confronted by Lattice QCD. We compare the two approaches for the $S$-wave decay of the exotic $1^{-+}$, and find excellent agreement. Results suggest that in Strong QCD, \qq~ creation occurs with S=1.

Pieter Kok

Optical noon states (|N,0> + |0,N>) are an important resource for Heisenberg-limited metrology and quantum lithography. The only known methods for creating noon states with arbitrary $N$ via linear optics and projective measurments seem to have a limited range of application due to imperfect phase control. Here, we show that bootstrapping techniques can be u

B. Kaviraj, S. K. Ghatak

Systematic measurements of stress impedance (SI) and magneto-impedance (MI) have been carried out using Co-rich amorphous ribbons of nominal composition Co71-xFexCr7Si8B14 (x = 0, 2) at various excitation frequencies and bias fields and at room temperature. The impedance, Z, for both the samples was found to be very sensitive functions of applied tensile str

Michal Marvan, Alexandre M. Vinogradov, Valery A. Yumaguzhin

In this paper basic differential invariants of generic hyperbolic Monge--Amp\`ere equations with respect to contact transformations are constructed and the equivalence problem for these equations is solved.

G. Quznetsov

In this paper I cite p.p. 100-117 of book G. Quznetsov, Probabilistic Treatment of Gauge Theories, in series Contemporary Fundamental Physics,ed. V. Dvoeglazov, Nova Sci. Publ., NY (2007). There I research a bound between neutrino and it&#39;s lepton.

E. O. Vasiliev, Yu. A. Shchekinov

We investigate thermal regime of the baryons behind shock waves arising in the process of virialization of dark matter halos. We find a fraction of the shocked gas cooled by radiation of HD molecules down to the temperature of the cosmic microwave background (CMB): this fraction increases sharply from about $f_{\rm c}\sim 10^{-3}$ for dark halos of $M=5\time

Giorgio Giacomelli

After some recollections of the early bubble chamber times, a brief overview of the golden age of the field is made, including its legacy and the use of bubble chamber events for the popularization of science.

Carlos D&#39;Andrea, Hoon Hong, Teresa Krick, Agnes Szanto

In 1853 Sylvester stated and proved an elegant formula that expresses the polynomial subresultants in terms of the roots of the input polynomials. Sylvester&#39;s formula was also recently proved by Lascoux and Pragacz by using multi-Schur functions and divided differences. In this paper, we provide an elementary proof that uses only basic properties of matr

U. Langenegger, M. Spira, A. Starodumov, P. Trueb

Strategies for Higgs boson searches require the knowledge of the total production cross section and the transverse momentum spectrum. The large transverse momentum spectrum of the Higgs boson produced in gluon fusion can be quite different in the Standard Model and the Minimal Supersymmetric Standard Model. In this paper we present a comparison of the Higgs

Stefano Montaldo, Irene I. Onnis

In this article we consider surfaces in the product space $\h^2\times \r$ of the hyperbolic plane $\h^2$ with the real line. The main results are: a description of some geometric properties of minimal graphs; new examples of complete minimal graphs; the classification of umbilical surfaces.

A. Chervov, D. Talalaev

The spectral curve is the key ingredient in the modern theory of classical integrable systems. We develop a construction of the ``quantum spectral curve&#39;&#39; and argue that it takes the analogous structural and unifying role on the quantum level also. In the simplest, but essential case the ``quantum spectral curve&#39;&#39; is given by the formula &#34

Dominic Verity

This paper develops the foundations of a simplicial theory of weak omega-categories, which builds upon the insights originally expounded by Ross Street in his 1987 paper on oriented simplices. The resulting theory of weak complicial sets provides a common generalisation of the theories of (strict) omega-categories, Kan complexes and Joyal&#39;s quasi-categor

Yongzhi Cao, Mingsheng Ying, Guoqing Chen

Fuzzy automata, whose input alphabet is a set of numbers or symbols, are a formal model of computing with values. Motivated by Zadeh&#39;s paradigm of computing with words rather than numbers, Ying proposed a kind of fuzzy automata, whose input alphabet consists of all fuzzy subsets of a set of symbols, as a formal model of computing with all words. In this

P. K. Pathak, G. S. Agarwal

We discuss quantum random walk of two photons using linear optical elements. We analyze the quantum random walk using photons in a variety of quantum states including entangled states. We find that for photons initially in separable Fock states, the final state is entangled. For polarization entangled photons produced by type II downconverter, we calculate t

A. Kay

We present a Hamiltonian that can be used for amplifying the signal from a quantum state, enabling the measurement of a macroscopic observable to determine the state of a single spin. We prove a general mapping between this Hamiltonian and an exchange Hamiltonian for arbitrary coupling strengths and local magnetic fields. This facilitates the use of existing

C. A. Bertulani

I investigate the elastic electron scattering off nuclei far from the stability line. The effects of the neutron and proton skins and halos on the differential cross sections are explored. Examples are given for the charge distribution in Sn isotopes and its relation to the neutron skin. The neutron halo in $^{11}$Li and the proton halo in $^{8}$B are also i

Donald Marolf, Leonardo Patiño

We compute the energy of 2+1 Minkowski space from a covariant action principle. Using Ashtekar and Varadarajan&#39;s characterization of 2+1 asymptotic flatness, we first show that the 2+1 Einstein-Hilbert action with Gibbons-Hawking boundary term is both finite on-shell (apart from past and future boundary terms) and stationary about solutions under arbitra

Mireille Aymar, Olivier Dulieu, Fernand Spiegelman

In this work we investigate the possibility to create cold Fr$\_2$, RbFr, and CsFr molecules through photoassociation of cold atoms. Potential curves, permanent and transition dipole moments for the Francium dimer and for the RbFr and RbCs molecules are determined for the first time. The Francium atom is modelled as a one valence electron moving in the field

Hans-Thomas Elze

We introduce functional degrees of freedom by a new gauge principle related to the phase of the wave functional. Thereby, quantum mechanical systems are seen as dissipatively embedded part of a nonlinear classical structure producing universal correlations. There are a fundamental length and an entropy/area parameter, besides standard couplings. For states t

P. Rabl, D. DeMille, J. M. Doyle, M. D. Lukin

We investigate a hybrid quantum circuit where ensembles of cold polar molecules serve as long-lived quantum memories and optical interfaces for solid state quantum processors. The quantum memory realized by collective spin states (ensemble qubit) is coupled to a high-Q stripline cavity via microwave Raman processes. We show that for convenient trap-surface d

A. Koulakov, A. Gelperin, D. Rinberg

We present a model for olfactory coding based on spatial representation of glomerular responses. In this model distinct odorants activate specific subsets of glomeruli, dependent upon the odorant&#39;s chemical identity and concentration. The glomerular response specificities are understood statistically, based on experimentally measured distributions of det

Edison Liang

We review recent PIC simulation results which show that double-sided irradiation of a thin over- dense plasma slab by ultra-intense laser pulses from both sides can lead to sustained comoving acceleration of surface electrons to energies much higher than the conventional ponderomotive limit. The acceleration stops only when the electrons drift transversely o

Sai Ravela, Virat Chatdarong

An algorithm to estimate motion from satellite imagery is presented. Dense displacement fields are computed from time-separated images of of significant convective activity using a Bayesian formulation of the motion estimation problem. Ordinarily this motion estimation problem is ill-posed; there are far too many degrees of freedom than necessary to represen

Yaroslav V. Kartashov, Lluis Torner

We discover multipole-mode solitons supported by the surface between two distinct periodic lattices imprinted in Kerr-type nonlinear media. Such solitons are possible because the refractive index modulation at both sides of the interface glues together their out-of-phase individual constituents. Remarkably, we find that the new type of solitons may feature h

A. Lakhtakia

On interrogation by a plane wave, the back-scattering efficiency of a nihility sphere is identically zero, and its extinction and forward-scattering efficiencies are higher than those of a perfectly conducting sphere.

Pascal Pernot

Using measured instrumental response functions for data deconvolution is a known source of uncertainty. This problem is revisited here with Bayesian data analysis an Monte Carlo simulations. Noise correlation induced by the convolution operator is identified as a major source of uncertainty which has been neglected in previous treatments of this problem. App

K. Nelissen, B. Partoens, I. Schweigert, F. M. Peeters

A binary system of classical charged particles interacting through a dipole repulsive potential and confined in a two-dimensional hardwall trap is studied by Brownian dynamics simulations. We found that the presence of small particles \emph{stabilizes} the angular order of the system as a consequence of radial fluctuations of the small particles. There is an

Soren Wichmann, Dietrich Stauffer, F. Welington S. Lima, Christian Schulze

This paper presents the results of the application of a bit-string model of languages (Schulze and Stauffer 2005) to problems of taxonomic patterns. The questions addressed include the following: (1) Which parameters are minimally ne eded for the development of a taxonomic dynamics leading to the type of distribution of language family sizes currently attest

N. Jachowicz, G. C. McLaughlin

Only weakly interacting, neutrinos are the principal messengers reaching us from the center of a supernova. Terrestrial neutrino telescopes, such as SNO and SuperKamiokande, can provide precious information about the processes in the core of a collapsing and exploding star. But the information about the supernova that a neutrino detector can supply, is restr

B. K. Agrawal, Shashi K. Dhiman, Raj Kumar

We parameterize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resultin

Zhiyong Xu, Yaroslav V. Kartashov, Lluis Torner

We introduce vector soliton complexes in nonlocal Kerr-type nonlinear media. We discover that under proper conditions the combination of nonlocality and vectorial coupling has a remarkable stabilizing action on multi-humped solitons. In particular, we find that stable bound states featuring several field oscillations in each soliton component do exist. This

R. Radha, C. Senthil Kumar, M. Lakshmanan, X. Y. Tang

In this paper, we investigate the (2+1) dimensional long wave-short wave resonance interaction (LSRI) equation and show that it possess the Painlevé property. We then solve the LSRI equation using Painlevé truncation approach through which we are able to construct solution in terms of three arbitrary functions. Utilizing the arbitrary functions present in th

Zhiyong Xu, Yaroslav V. Kartashov, Lluis Torner

We address the impact of asymmetric nonlocal diffusion nonlinearity on the properties of gap solitons supported by photorefractive crystal with an imprinted optical lattice. We reveal how the asymmetric nonlocal response alters the domains of existence and the stability of solitons originating from different gaps. We find that in such media gap solitons ceas

Anthony M. Bloch, Arieh Iserles, Jerrold E. Marsden, Tudor S. Ratiu

This paper shows that the left-invariant geodesic flow on the symplectic group relative to the Frobenius metric is an integrable system that is not contained in the Mishchenko-Fomenko class of rigid body metrics. This system may be expressed as a flow on symmetric matrices and is bi-Hamiltonian. This analysis is extended to cover flows on symmetric matrices

Peter Petrov

We present a solution for Nash problem for stable toric varieties. We also introduce Nash problem for pairs and prove it for toric pairs.

Johann Cigler

Modifying an idea of E. Brietzke we give simple proofs for the recurrence relations of some sequences of binomial sums which have previously been obtained by other more complicated methods.

David Nadler

We give a geometric construction of tilting perverse sheaves using stratified Morse theory, torus actions, and nearby cycles.

Bjoern Grohmann

In this article an upper bound for the first consecutive zeros of the Fermat quotient is given in terms of the zeros of a Mirimanoff polynomial. This bound is obtained by investigating a relation between these polynomials and the factor system of Gauss sums of a certain number field.

Francesco Caravenna, Giambattista Giacomin, Lorenzo Zambotti

The aim of this paper is twofold: - To give an elementary and self-contained proof of an explicit formula for the free energy for a general class of polymer chains interacting with an environment through periodic potentials. This generalizes a result in [Bolthausen and Giacomin, AAP 2005] in which the formula is derived by using the Donsker-Varadhan Large De

Michael Stoll

The main result of this note is that there are at most seven rational points (including the one at infinity) on the curve C_A with the affine equation y^2 = x^5 + A (where A is a tenth power free integer) when the Mordell-Weil rank of the Jacobian of C_A is one. This bound is attained for A = 18^2.

Ling Lei

This work is concerned with the identification problem for what we call the perturbation term or error term in a parabolic partial differential equation, through its approximate periodic solutions. The observation is made over a subregion of the physical domain. The existence and uniqueness problem of the approximate periodic solutions is studied in the firs

Predrag Rajkovic, Marko D. Petkovic, Paul Barry

We discuss the properties of the Hankel transformation of a sequence whose elements are the sums of consecutive generalized Catalan numbers and find their values in the closed form.

J. Fernandez de Bobadilla, I. Luengo, A. Melle-Hernandez, A. Nemethi

Let $C$ be an irreducible projective plane curve in the complex projective space ${\mathbb{P}}^2$. The classification of such curves, up to the action of the automorphism group $PGL(3,{\mathbb{C}})$ on ${\mathbb{P}}^2$, is a very difficult open problem with many interesting connections. The main goal is to determine, for a given $d$, whether there exists a p

J. Fernandez de Bobadilla, I. Luengo, A. Melle-Hernandez, A. Nemethi

It is a very old and interesting open problem to characterize those collections of embedded topological types of local plane curve singularities which may appear as singularities of a projective plane curve C of degree d. The goal of the present article is to give a complete (topological) classification of those cases when C is rational and it has a unique s

Antonio Cañete

In this work we classify the stable regions (second order minima of perimeter under an area constraint) in tori of revolution with piecewise continuous decreasing Gauss curvature from the longest parallel and with a horizontal symmetry. Some applications to isoperimetric problems are also given.

Yuzo Maruyama, Akimichi Takemura

We give a sufficient condition for admissibility of generalized Bayes estimators of the location vector of spherically symmetric distribution under squared error loss. Compared to the known results for the multivariate normal case, our sufficient condition is very tight and is close to being a necessary condition. In particular we establish the admissibility

Dominic Verity

This paper continues the development of a simplicial theory of weak omega-categories, by studying categories which are enriched in weak complicial sets. These complicial Gray-categories generalise both the Kan complex enriched categories of homotopy theory and the Gray-categories of weak 3-category theory. We derive a simplicial nerve construction, which is

Everett W. Howe

Let C be a supersingular genus-2 curve over an algebraically closed field of characteristic 3. We show that if C is not isomorphic to the curve y^2 = x^5 + 1 then up to isomorphism there are exactly 20 degree-3 maps phi from C to the elliptic curve E with j-invariant 0. We study the coarse moduli space of triples (C,E,phi), paying particular attention to que

Mohammad T. Dibaei, Alireza Nazari

Assume that $R = \bigoplus_{i\in \mathbb{N}_{0}} R_{i}$ is a homogeneous graded Noetherian ring, and that $M$ is a $ \mathbb{Z}$--graded $R$--module, where $ \mathbb{N}_{0}$ (resp. $ \mathbb{Z}$) denote the set all non--negative integers (resp. integers). The set of all homogeneous attached prime ideals of the top non--vanishing local cohomology module of a

S. Caenepeel, E. De Groot, J. Vercruysse

We propose a class of infinite comatrix corings, and describe them as colimits of systems of usual comatrix corings. The infinite comatrix corings of El Kaoutit and Gómez Torrecillas are special cases of our construction, which in turn can be considered as a special case of the comatrix corings introduced recently by Gómez Torrecillas an the third author.

Louis J. Billera, Samuel K. Hsiao, J. Scott Provan

We construct CW spheres from the lattices that arise as the closed sets of a convex closure, the meet-distributive lattices. These spheres are nearly polytopal, in the sense that their barycentric subdivisions are simplicial polytopes. The complete information on the numbers of faces and chains of faces in these spheres can be obtained from the defining latt

Joost Vercruysse

We unify and generalize different notions of local units and local projectivity. We investigate the connection between these properties by constructing elementary algebras from locally projective modules. Dual versions of these constructions are discussed, leading to corings with local comultiplications, corings with local counits and rings with local multip

Simon Scott

For a smooth family F of admissible elliptic pseudodifferential operators with differential form coefficients associated to a geometric fibration of manifolds M--> B we show that there is a natural zeta-form z(F,s) and zeta-determinant- form det(F) in the de-Rham algebra of smooth differential forms, generalizing the classical single operator spectral zeta f

Nobuhiro Honda

We consider self-dual metrics on 3CP^2 of positive scalar curvature admitting a non-trivial Killing field, but which is not conformally isometric to LeBrun&#39;s metrics. Firstly, we determine defining equations of the twistor spaces of such self-dual metrics. Next we prove that conversely, the complex threefolds defined by the equations always become twisto

Shouchuan Zhang, Yao-Zhong Zhang

The relation between crossed product and $H$-Galois extension in braided tensor category ${\cal C}$ with equivalisers and coequivalisers is established. That is, it is shown that if there exist an equivaliser and a coequivaliser for any two morphisms in ${\cal C}$, then $A = B #_σH$ is a crossed product algebra if and only if the extension $A/B$ is Galois, t

S. Majid

This is a self-contained introduction to quantum Riemannian geometry based on quantum groups as frame groups, and its proposed role in quantum gravity. Much of the article is about the generalisation of classical Riemannian geometry that arises naturally as the classical limit; a theory with nonsymmetric metric and a skew version of metric compatibilty. Mean

Tamerlan Saidov, Alexander Zhuk

We investigate $D$-dimensional gravitational model with curvature-quadratic and curvature-quartic correction terms: $R+R^2+R^4$. It is assumed that the corresponding higher dimensional spacetime manifold undergos a spontaneous compactification to a manifold with warped product structure. Special attention is paid to the stability of the extra-dimensional fac

S. Majid

We provide a self-contained introduction to the quantum group approach to noncommutative geometry as the next-to-classical effective geometry that might be expected from any successful quantum gravity theory. We focus particularly on a thorough account of the bicrossproduct model noncommutative spacetimes of the form [t,x_i]=i λx_i and the correct formulatio

Pavel Kovtun, A. Zee

We show that the observed pattern for neutrino mixing arises naturally if neutrinos are composites of more elementary constituents carrying an SU(2) quantum number we call lepospin.

M. E. Bracco, A. Cerqueira, M. Chiapparini, A. Lozea

We calculate the strong form factors and coupling constants of $ D^* D_s K$ and $D_s^* D K$ vertices using the QCD sum rules technique. In each case we have considered two different cases for the off-shell particle in the vertex: the ligthest meson and one of the heavy mesons. The method gives the same coupling constant for each vertex. When the results for

Gerhard Ecker

After a brief historical review of the emergence of QCD as the quantum field theory of strong interactions, the basic notions of colour and gauge invariance are introduced leading to the QCD Lagrangian. The second lecture is devoted to perturbative QCD, from tree-level processes to higher-order corrections in renormalized perturbation theory, including jet p

Vishnu M. Bannur

We discuss a new single parameter quasi-particle model and study the thermodynamics of (2+1)-flavor quark gluon plasma (QGP). Our model with a single parameter explains remarkably well the lattice simulation results of Fodor et. al. Phys. Lett. B568, 73 (2003).

O. I. Piskounova

The predictions were done for asymmetry between production spectra of Lambda^0 and antiLambda^0 at the energy of LHC experiments. The value of A(s) should be situated in the band between two curves that are calculated in Quark-Gluon String Model with two possible values of intercept alpha_{SJ}(0)=0,5 and 0,9. Both curves describe the asymmetries measured at

Jiunn-Wei Chen, Donal O&#39;Connell, Ruth S. Van de Water, Andre Walker-Loud

We calculate isospin 2 pion-pion scattering in chiral perturbation theory for a partially quenched, mixed action theory with Ginsparg-Wilson valence quarks and staggered sea quarks. We point out that for some scattering channels, the power-law volume dependence of two pion states in nonunitary theories such as partially quenched or mixed action QCD is identi

G. Davatz, A. S. Giolo-Nicollerat, M. Zanetti

The top quark and its properties within and beyond the Standard Model will be extensively studied at the incoming Large Hadron Collider. Nonetheless the top quark will play the role of the main background for most of the Higgs and new physics searches. In this paper the top as a background to H=>WW=>2l2nu Higgs discovery channel will be studied. The current

D0 Collaboration, V. Abazov

We present the results of a search for the production of an excited state of the muon, mu*, in proton antiproton collisions at sqrt s = 1.96 TeV. The data have been collected with the D0 experiment at the Fermilab Tevatron Collider and correspond to an integrated luminosity of approximately 380 pb^-1. We search for mu* in the process p pbar -> mu* mu, with t

The DELPHI Collaboration, J. Abdallah

Double-tagged interactions of photons with virtualities Q^2 between 10 GeV^2 and 200 GeV^2 are studied with the data collected by DELPHI at LEPII from 1998 to 2000, corresponding to an integrated luminosity of 550 pb^{-1}. The gam* gam* -> mu+mu- data agree with QED predictions. The cross-section of the reaction gam* gam* -> hadrons is measured and compared

The DELPHI Collaboration, J. Abdallah

Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predic

Paulo da Costa Moreira

It is proposed a formalism of quantification of the electric charges in the Kaluza Klein theory of five dimensions and a explanation of the cause of the variation of the electromagnetic fine-structure constant in cosmological times.There is a formalism that eliminates the problem that impeached the KK theory to complete the unification of the electromagnetic

Jun Chen, Toby Berger

We introduce a distributed source coding scheme called successive Wyner-Ziv coding. We show that any point in the rate region of the quadratic Gaussian CEO problem can be achieved via the successive Wyner-Ziv coding. The concept of successive refinement in the single source coding is generalized to the distributed source coding scenario, which we refer to as

Loreto Bravo, Leopoldo Bertossi

For several reasons a database may not satisfy a given set of integrity constraints(ICs), but most likely most of the information in it is still consistent with those ICs; and could be retrieved when queries are answered. Consistent answers to queries wrt a set of ICs have been characterized as answers that can be obtained from every possible minimally repai