October 2006 arXiv papers — page 40

Francesco Cianfrani, Irene Milillo, Giovanni Montani

We outline that, in a Kaluza-Klein framework, not only the electro-magnetic field can be geometrized, but also the dynamics of a charged spinning particle can be inferred from the motion in a 5-dimensional space-time. This result is achieved by the dimensional splitting of Papapetrou equations and by proper identifications of 4-dimensional quantities.

L. V. Fil'kov, V. L. Kashevarov

Recent experimental pion polarizability data are reviewed and analyzed. Data on the radiative π^+ meson photoproduction on the proton at MAMI has been used to determine the difference of the electric and magnetic dipole polarizabilities of the charged pion. Fits of the experimental data to the total cross sections of the processes γγ->π^0π^0 and γγ->π^\pmπ^\

M. Jarvinen

The transverse single-spin asymmetry A_N observed in high energy proton-proton collisions p^\uparrow p \to pi X has been found to increase with the momentum fraction x_F of the pion up to the largest measured x_F \sim 0.8, where A_N \simeq 40%. We consider the possibility that the asymmetry is due to a non-perturbatively generated spin-flip coupling in soft

P. Bonifacio, P. Molaro, T. Sivarani, R. Cayrel

Aims. This study aims to determine the level and constancy of the Spite plateau as definitively as possible from homogeneous high-quality VLT-UVES spectra of 19 of the most metal-poor dwarf stars known. Methods. Our high-resolution (R ~ 43000), high S/N spectra are analysed with OSMARCS 1D LTE model atmospheres and turbospectrum synthetic spectra to determin

Camille Laurent-Gengoux

We use the techniques of integration of Poisson manifolds into symplectic Lie groupoids to build symplectic resolutions (= desingularizations) of the closure of a symplectic leaf. More generally, we show how Lie groupoids can be used to lift singularities, in particular when one imposes a compatibility condition with an additional structure given by a multi-

Miquel Montero

American options are financial instruments that can be exercised at any time before expiration. In this paper we study the problem of pricing this kind of derivatives within a framework in which some of the properties --volatility and dividend policy-- of the underlaying stock can change at a random instant of time, but in such a way that we can forecast the

Zhengfeng Ji, Guoming Wang, Runyao Duan, Yuan Feng

The efficiency of parameter estimation of quantum channels is studied in this paper. We introduce the concept of programmable parameters to the theory of estimation. It is found that programmable parameters obey the standard quantum limit strictly; hence no speedup is possible in its estimation. We also construct a class of non-unitary quantum channels whose

Charles Hill

There are many cases where the interaction between two qubits is not precisely known, but single qubit operations are available. In this paper we show how, regardless of an incomplete knowledge of the strength or form of the interaction between two qubits, it is often possible to construct a CNOT gate which has arbitrarily high fidelity. In particular, we sh

Julia E. Bergner

We modify a previous result, which showed that certain diagrams of spaces are essentially simplicial monoids, to construct diagrams of spaces which model simplicial groups. Furthermore, we show that these diagrams can be generalized to models for Segal groupoids. We then modify Segal's model for simplicial abelian monoids in such a way that it becomes a

L. P. Colatto, A. L. A. Penna, W. C. Santos

The study of topological defects occurring in vector and tensor fields is an intriguing subject and little explored in the literature. In this article, we analyze the topological defects arising from the spontaneous violation of Lorentz symmetry for a vector matter field with Chern-Simons term in a Minkowski spacetime in $(1+2)D$. As a consequence, the resul

N. Matagne, Fl. Stancu

So far, the masses of excited states of mixed orbital symmetry and in particular those of nonstrange $[{\bf 70},1^-]$ baryons derived in the $1/N_c$ expansion were based on the separation of a system of $N_c$ quarks into a symmetric core and an excited quark. Here we avoid this separation and show that an advantage of this new approach is to substantially re

Anne-Claire Dupuis

Thin films of V2O3 have been grown on Au(111) and W(110). It is possible to prepare two different surface terminations: the first one is vanadium terminated whereas the second one exhibits additional oxygen atoms, forming vanadyl groups with the surface vanadium atoms. The electronic structure was studied for both terminations by photoelectron spectroscopy.

Tim Dokchitser, Vladimir Dokchitser

Let A be an abelian variety over a number field K. An identity between the L-functions L(A/K_i,s) for extensions K_i of K induces a conjectural relation between the Birch-Swinnerton-Dyer quotients. We prove these relations modulo finiteness of Sha, and give an analogous statement for Selmer groups. Based on this, we develop a method for determining the parit

Antonio Frasca, Patrick Guillout, Rubens Freire-Ferrero, Ettore Marilli

The cross-correlation between the ROSAT all-sky survey (~150000 sources) and the Tycho mission (~1000000 stars) catalogs has selected about 14000 stellar X-ray sources (RasTyc sample, Guillout et al. 1999). About 200-300 stars have been spectroscopically observed at high resolution both in the Halpha and LiI lambda-6708 regions with Elodie and Aurelie spectr

Sylvain Condamin, Olivier Bénichou, Michel Moreau

In this paper we present a computation of the mean first-passage times both for a random walk in a discrete bounded lattice, between a starting site and a target site, and for a Brownian motion in a bounded domain, where the target is a sphere. In both cases, we also discuss the case of two targets, including splitting probabilities, and conditional mean fir

Benoit Collins, Piotr Sniady

We study the asymptotics of representations of a fixed compact Lie group. We prove that the limit behavior of a sequence of such representations can be described in terms of certain random matrices; in particular operations on representations (for example: tensor product, restriction to a subgroup) correspond to some natural operations on random matrices (re

Sergey Gubin

The ATSP polytope can be expressed by asymmetric polynomial size linear program.

M. Goethe, T. Aspelmeier

This paper has been withdrawn because we have since found an analytic theory (arXiv:0712.3586) which shows that the dominant contribution to the free energy fluctuations comes from the region t\approxτ. This regime was unfortunately undetectable from our available numerical data.

M. Longhetti, P. Saracco, P. Severgnini, R. Della Ceca

We present the morphological analysis based on HST-NIC2 (0.075 arcsec/pixel) images in the F160W filter of a sample of 9 massive field (> 10^{11} M_\odot) galaxies spectroscopically classified as early-types at 1.2<z<1.7. Our analysis shows that all of them are bulge dominated systems. In particular, 6 of them are well fitted by a de Vaucouleurs profile (n=4

Giacomo Mauro D&#39;Ariano, Paolo Perinotti

We consider the general measurement scenario in which the ensemble average of an operator is determined via suitable data-processing of the outcomes of a quantum measurement described by a POVM. We determine the optimal processing that minimizes the statistical error of the estimation.

Weonjong Lee

We review recent progress in calculating kaon spectrum, pseudoscalar meson decay constants, $B_K$, $ε&#39;/ε$, $K\to ππ$ matrix elements, kaon semileptonic form factors, and moments of kaon distribution amplitudes on the lattice. We also address the issue of how best to improve the staggered fermion formulation for the action and operators.

Gian Paolo Beretta

A seldom recognized fundamental difficulty undermines the concept of individual ``state&#39;&#39; in the present formulations of quantum statistical mechanics (and in its quantum information theory interpretation as well). The difficulty is an unavoidable consequence of an almost forgotten corollary proved by E. Schroedinger in 1936 and perused by J.L. Park,

Jongjeong Kim, Taegil Bae, Weonjong Lee, Stephen R. Sharpe

We present preliminary results for $B_K$ calculated using improved staggered fermions with a mixed action (HYP-smeared staggered valence quarks and AsqTad staggered sea quarks). We investigate the effect of non-degenerate quarks on $B_K$ and attempt to estimate the ${\cal O}(a^2)$ effect due to non-Goldstone pions in loops. We fit the data to continuum parti

Robert Osburn, Carsten Schneider

Let p be an odd prime. In 1984, Greene introduced the notion of hypergeometric functions over finite fields. Special values of these functions have been of interest as they are related to the number of F_p points on algebraic varieties and to Fourier coefficients of modular forms. In this paper, we explicitly determine these functions modulo higher powers of

Taegil Bae, Jongjeong Kim, Weonjong Lee, Stephen R. Sharpe

We present results for the pion multiplet spectrum calculated using both unimproved staggered fermions and improved HYP-smeared staggered fermions. In the case of unimproved staggered fermions, we observe (consistent with previous work) that ${\cal O}(a^2)$ taste symmetry breaking effects are large and comparable to the $\approx {\cal O}(p^2)$ contributions

Maciej Dunajski, Simon West

We review the subject of four dimensional anti-self-dual conformal structures with signature (+ + - -). Both local and global questions are discussed. Most of the material is well known in the literature and we present it in a way which underlines the connection with integrable systems. Some of the results - e.g. the Lax pair characterisation of the scalar-f

K. S. Cheng, V. V. Usov

It is shown that nuggets of strange quark matter may be extracted from the surface of pulsars and accelerated by strong electric fields to high energies if pulsars are strange stars with the crusts, comprised of nuggets embedded in a uniform electron background. Such high energy nuggets called usually strangelets give an observable contribution into galactic

K. Mattila, M. Juvela, K. Lehtinen

Bright emission nebulae, or HII regions, around hot stars are readily seen in H-alpha light. However, the all-pervasive faint H-alpha emission has only recently been detected and mapped over the whole sky. Mostly the H-alpha emission observed along a line of sight is produced by ionised gas in situ. There are, however, cases where all or most of the H-alpha

Antonio Padilla

In this paper we provide a short review of the main results developed in hep-th/0604086. We focus on linearised vacuum perturbations about the self-accelerating branch of solutions in the DGP model. These are shown to contain a ghost in the spectrum for any value of the brane tension. We also comment on hep-th/0607099, where some counter arguments have been

H. Sadeghi, S. Bayegan, Harald W. Griesshammer

The cross section for the thermal neutron capture by the deuteron is calculated with pionless Effective Field Theory(EFT). No new Three-Nucleon forces are needed up to next-to-next-to-leading order in order to achieve cut-off independent results, besides those fixed by the triton binding energy and Nd scattering length in the triton channel. The cross-sectio

Hans-Joerg Fahr, Mark Siewert

There is a longstanding mystery connected with the radiotracking of distant interplanetary spaceprobes like ULYSSES, Galileo and especially the two NASA probes PIONEER 10 and 11. Comparing radiosignals outgoing from the earth to the probe and ingoing again from the probes do show anomalous frequency shifts which up to now have been explained as caused by ano

Sang-Hoon Kim

With the integral representation of Bose functions, the Bose-Einstein condensation of non-interacting bosons in a three-dimensional harmonic trap was studied. The relation between the particle number and its phase transition temperature was clarified. Some next-order terms in the thermodynamic expansions were obtained. We plotted the chemical potential, the

Carlo Magagna

For a positive integer $N$, we define the N-rank of a non singular integer $d\times d$ matrix $A$ to be the maximum integer $r$ such that there exists a minor of order $r$ whose determinant is not divisible by $N$. Given a positive integer $r$, we study the growth of the minumum integer $k$, such that $A^k-I$ has N-rank at most $r$, as a function of $N$. We

M. Kozlov, E. Levin, V. Khachatryan, J. Miller

In this paper we discuss the processes of diffractive production in the framework of the BFKL Pomeron calculus in zero transverse dimension. Considering the diffractive production of a bunch of particles with not very large masses, namely, $\ln\Lb M^2/m^2 \Rb \ll \frac{1}{\bas} \ln\Lb \frac{N^2_c}{\bas^2}\Rb$, we found explicit formulae for calculation of th

BES Collaboration, M. Ablikim

Using 14M $ψ(2S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $ψ(2S)\toπ^+π^-J/ψ, J/ψ\to μ^+μ^-$. The $π^+π^-$ mass spectrum, distinctly different from phase space, suggests $σ$ production in this process. Two different theoretical schemes are used in the global fit to the data. The results are consistent

Michael Potthoff, Matthias Balzer

Based on a functional-integral formalism, a generalization of the self-energy-functional theory (SFT) is proposed which is applicable to systems of interacting electrons with disorder. Similar to the pure case without disorder, a variational principle is set up which gives the physical (disorder) self-energy as a stationary point of the (averaged) grand pote

László Tóth

The integer $d$ is called an exponential divisor of $n=\prod_{i=1}^r p_i^{a_i}>1$ if $d=\prod_{i=1}^r p_i^{c_i}$, where $c_i \mid a_i$ for every $1\le i \le r$. The integers $n=\prod_{i=1}^r p_i^{a_i}, m=\prod_{i=1}^r p_i^{b_i}>1$ having the same prime factors are called exponentially coprime if $(a_i,b_i)=1$ for every $1\le i\le r$. In the paper we investig

Vishwas S. Purohit, Manish Shinde, Shirshendu Dey, Renu Pasricha

Deposits of one-dimensional nanostructures of zinc with diameters of 90-120 nm have been obtained by means of sputtering in an Electron Cyclotron Resonance (ECR) plasma reactor. The sputtering has been made effective by using a negatively biased cylindrical target in a hollow cathode geometry. The nanocrystalline films deposited on the glass substrate were s

Andrea Banfi

A short overview of recent developments on resummations in QCD is presented.

Vesselin Petkov

Should physicists deal with the question of the reality of Minkowski space (or any relativistic spacetime)? It is argued that they should since this is a question about the dimensionality of the world at the macroscopic level and it is physics that should answer it.

Tomoo Matsumura

Let X be a compact almost complex manifold with an action of a finite group G. We compute the algebra of G^n coinvariants of the stringy cohomology (math.AG/0104207) of X^n with an action of a wreath product of G. We show that it is isomorphic to the algebra A{S_n} defined by Lehn and Sorger (math.AG/0012166) where we set A to be the orbifold cohomology of [

Eylee Jung, D. K. Park

The emission spectra for the spin-1 photon fields are computed when the spacetime is a $(4+n)$-dimensional Schwarzschild phase. For the case of the bulk emission we compute the spectra for the vector mode and scalar mode separately. Although the emissivities for the scalar mode is larger than those for the vector mode when $n$ is small, the emissivities for

Scott Corry, Florian Pop

We prove a pro-$p$ Hom-form of the birational anabelian conjecture for function fields over sub-$p$-adic fields. Our starting point is the Theorem of Mochizuki in the case of transcendence degree 1.

I. Giannakis, Defu Hou, Jia-rong Li, Hai-cang Ren

We study the Anderson Localization effect on the shear viscosity in a system with random medium by Kubo formula. We show that this effect can reduce the shear viscosity nonperturbatively. Then we discuss its possible implementation in heavy-ion collisions, where the created heavy bound states or other collective modes may play the role of the random scattere

T. Yamazaki

We calculate $\Delta I = 3/2$ kaon decay matrix elements using domain wall fermions and the DBW2 gauge action at one coarse lattice spacing corresponding to $a^{-1} = 1.3$ GeV. We employ the Lellouch and L\"uscher formula and its extention for non-zero total momentum to extract the infinite volume, center-of-mass frame decay amplitudes. The decay amplitudes

Ivan Booth, Stephen Fairhurst

We study the geometry and dynamics of both isolated and dynamical trapping horizons by considering the allowed variations of their foliating two-surfaces. This provides a common framework that may be used to consider both their possible evolutions and their deformations as well as derive the well-known flux laws. Using this framework, we unify much of what i

The Belle Collaboration

A high statistics study of the reaction $γγ\to π^+π^-π^0$ has been performed with the Belle detector using a data sample of 26 fb$^{-1}$ collected at $\sqrt{s}=10.58\GeVcsq$. A spin-parity analysis shows dominance of the $J^P=2^+$ helicity 2 wave for three-pion invariant masses from 1 to 3 \GeVcsq. The invariant mass distribution exhibits $a_2(1320)$, $a_2(1

A. S. Villar, M. Martinelli, C. Fabre, P. Nussenzveig

We calculate the quantum correlations existing among the three output fields (pump, signal, and idler) of a triply resonant non-degenerate Optical Parametric Oscillator operating above threshold. By applying the standard criteria [P. van Loock and A. Furusawa, Phys. Rev. A 67, 052315 (2003)], we show that strong tripartite continuous-variable entanglement is

T. Schulte-Herbrueggen, A. Spoerl

Generalising in the sense of Hahn&#39;s spin echo, we completely characterise those unitary propagators of effective multi-qubit interactions that can be inverted solely by {\em local} unitary operations on $n$ qubits (spins-$\tfrac{1}{2}$). The subset of $U\in \mathbf{SU}(2^n)$ satisfying $U^{-1}=K_1 U K_2$ with pairs of local unitaries $K_1, K_2\in\mathbf{

E. Brion, L. H. Pedersen, K. Molmer

This paper deals with different ways to extract the effective two-dimensional lower level dynamics of a lambda system excited by off-resonant laser beams. We present a commonly used procedure for elimination of the upper level, and we show that it may lead to ambiguous results. To overcome this problem and better understand the applicability conditions of th

Tony J. G. Apollaro, Francesco Plastina

We discuss the effect of a single diagonal defect on both the static and dynamical properties of entanglement in a spin chain. We show that entanglement localizes at the defect and discuss its localization length, arguing that this can be used as a mean to store entanglement. We also show that the impurity site can behave as an entanglement mirror and charac

S N Sandhya

Absorption profile of a four-level ladder atomic system interacting with three driving fields is studied perturbatively and analytical results are presented. Numerical results where the driving field strengths are treated upto all orders are presented. The absorption features is studied in two regimes, i) the weak middle transition coupling, i.e. $Ω_2 << Ω_{

D. V. Brazhnikov, A. V. Taichenachev, A. M. Tumaikin, V. I. Yudin

The parameters of nonlinear absorption magneto-optical resonances in the Hanle configuration have been studied as functions of the ellipticity of a traveling light wave. It has been found that these parameters (amplitude, width, and amplitude-to-width ratio) depend strongly on the polarization of the light wave. In particular, the resonance amplitude can inc

Joonwoo Bae, Antonio Acin

We provide a general formalism to characterize the cryptographic properties of quantum channels in the realistic scenario where the two honest parties employ prepare and measure protocols and the known two-way communication reconciliation techniques. We obtain a necessary and sufficient condition to distill a secret key using this type of schemes for Pauli q

Boleslaw Kacewicz

We establish essentially optimal bounds on the complexity of initial-value problems in the randomized and quantum settings. For this purpose we define a sequence of new algorithms whose error/cost properties improve from step to step. These algorithms yield new upper complexity bounds, which differ from known lower bounds by only an arbitrarily small positiv

Naoto Morikawa

This paper proposes a new mathematical approach to characterize native protein structures based on the discrete differential geometry of tetrahedron tiles. In the approach, local structure of proteins is classified into finite types according to shape. And one would obtain a number sequence representation of protein structures automatically. As a result, it

K. A. Milton

Julian Schwinger&#39;s influence on twentieth century science is profound and pervasive. Of course, he is most famous for his renormalization theory of quantum electrodynamics, for which he shared the Nobel Prize with Richard Feynman and Sin-itiro Tomonaga. But although this triumph was undoubtedly his most heroic work, his legacy lives on chiefly through su

Z. Yin, Tao Tang

To investigate the finite time singularity in three-dimensional (3D) Euler flows, the simplified model of 3D axisymmetric incompressible fluids (i.e., two-dimensional Boussinesq approximation equations) is studied numerically. The system describes a cap-like hot zone of fluid rising from the bottom, while the edges of the cap lag behind, forming eye-like vor

Aaron Clauset, Cristopher Moore, M. E. J. Newman

One property of networks that has received comparatively little attention is hierarchy, i.e., the property of having vertices that cluster together in groups, which then join to form groups of groups, and so forth, up through all levels of organization in the network. Here, we give a precise definition of hierarchical structure, give a generic model for gene

Akinbo Ojo

Assuming that the universe is a system obedient to known thermodynamic laws and equations, here we explore whether it is a possibility for the universe to exist and evolve without any cosmic structure or force necessarily emerging within it. From symmetry considerations and the invariance of Boltzmann&#39;s constant during the experiment, we infer that it is

Bernhard Rothenstein, Stefan Popescu

We begin with a scenario that involves point-like observers starting at t=0 from the origin O of an inertial reference frame. They move with all possible proper accelerations in the positive direction of the OX axis. Equipped with light sources the accelerating observers get involved in experiments like Doppler Effect, radar detection and radar echo. We deri

Tatiana Latychevskaia, Hans-Werner Fink

While the invention of holography by Dennis Gabor truly constitutes an ingenious concept, it has ever since been troubled by the so called twin image problem limiting the information that can be obtained from a holographic record. Due to symmetry reasons there are always two images appearing in the reconstruction process. Thus, the reconstructed object is ob

V. M. Suslov, M. A. Braun, I. Filikhin, B. Vlahovic

A new computational method for solving the configuration-space Faddeev equations for the breakup scattering problem has been applied to nd scattering both below and above the two-body threshold.

M. J. Vicente Vacas

Some recent developments in chiral dynamics of hadrons and hadrons in a medium are presented. Unitary schemes based on chiral Lagrangians describe some hadronic states as being dynamically generated resonances. We discuss how standard quantum many body techniques can be used to calculate the properties of these dynamically generated and other hadrons in the

A. K. Chaudhuri

Using the QGP motivated threshold model, where all the $J/ψ$&#39;s are suppressed above a threshold density, we have analyzed the preliminary PHENIX data on the centrality dependence of nuclear modification factor for $J/ψ$&#39;s in Cu+Cu and in Au+Au collisions, at RHIC energy, $\sqrt{s}_{NN}$=200 GeV. Centrality dependence of $J/ψ$ suppression in Au+Au col

D. N. Poenaru, R. A. Gherghescu, N. Carjan

A new version of the semiempirical formula based on fission approach of alpha decay is derived, by using the optimum values of the fitting parameters determined for even-even nuclei, combined with hindrance factors for even-odd, odd-even, and odd-odd nuclides. The deviations from experimental data for two regions of nuclear chart (493 alpha emitters with Z=5

J. Toivanen

A method to accelerate the matrix-vector products of j-scheme nuclear Shell-Model Configuration Interaction (SMCI) calculations is presented. The method takes advantage of the matrix product form of the j-scheme proton-neutron Hamiltonian matrix. It is shown that the method can speed up unrestricted large-scale pf-shell calculations by up to two orders of ma

Doron Gazit, Nir Barnea, Sonia Bacca, Winfried Leidemann

Three well known photonuclear sum rules (SR), i.e. the Thomas-Reiche-Kuhn, the bremsstrahlungs and the polarizability SR are calculated for 4He with the realistic nucleon-nucleon potential Argonne V18 and the three-nucleon force Urbana IX. The relation between these sum rules and the corresponding energy weighted integrals of the cross section is discussed.

Arkadiusz Syta, Grzegorz Litak

We adopt the &#39;0-1&#39; test for chaos using Brownian motion chains to identify the dynamics of the Ricker&#39;s population model. In the &#39;0-1&#39; test &#39;0&#39; is related to regular motion while &#39;1&#39; is associated with chaotic motion. The identified regular and chaotic types of solutions have been confirmed by means of recurrence plots.

Grzegorz Litak, Arkadiusz Syta, Marek Borowiec

We examine the Melnikov criterion for transition to chaos in case of a single degree of freedom nonlinear oscillator with the Ueda well potential and an external periodic excitation term. Using effective Hamiltonian we have examined homoclinic orbits and cross-sections of stable and unstable manifolds which gave the condition of transition to chaos through a

Sergey Nazarenko, Miguel Onorato

We study turbulence and Bose-Einstein condensation (BEC) within the two-dimensional Gross-Pitaevski (GP) model. In the present work, we compute decaying GP turbulence in order to establish whether BEC can occur without forcing and if there is an intensity threshold for this process. We use the wavenumber-frequency plots which allow us to clearly separate the

R. O. Popovych, C. Sophocleous, O. O. Vaneeva

A model &#34;remarkable&#34; fin equation is singled out from a class of nonlinear (1+1)-dimensional fin equations. For this equation a number of exact solutions are constructed by means of using both classical Lie algorithm and different modern techniques (functional separation of variables, generalized conditional symmetries, hidden symmetries etc).

M. Gubinelli

The stack of iterated integrals of a path is embedded in a larger algebraic structure where iterated integrals are indexed by decorated rooted trees and where an extended Chen&#39;s multiplicative property involves the Dürr-Connes-Kreimer coproduct on rooted trees. This turns out to be the natural setting for a non-geometric theory of rough paths.

Vladimir Derkach, Seppo Hassi, Mark Malamud, Henk de Snoo

The Kre\uın-Naimark formula provides a parametrization of all selfadjoint exit space extensions of a, not necessarily densely defined, symmetric operator, in terms of maximal dissipative (in $\dC_+$) holomorphic linear relations on the parameter space (the so-called Nevanlinna families). The new notion of a boundary relation makes it possible to interpret th

Oliver Nash

This thesis was motivated by a desire to understand the natural geometry of hyperbolic monopole moduli spaces. We take two approaches. Firstly we develop the twistor theory of singular hyperbolic monopoles and use it to study the geometry of their charge 1 moduli spaces. After this we introduce a new way to study the moduli spaces of both Euclidean and hyper

Valentin Ferenczi, Alain Louveau, Christian Rosendal

It is proved that the relation of isomorphism between separable Banach spaces is a complete analytic equivalence relation, i.e., that any analytic equivalence relation Borel reduces to it. Thus, separable Banach spaces up to isomorphism provide complete invariants for a great number of mathematical structures up to their corresponding notion of isomorphism.

J. A. Vera

In this paper the non-canonical Hamiltonian dynamics of a gyrostat in the three body problem will be examined. By means of geometric-mechanics methods some relative equilibria of the dynamics of a gyrostat in Newtonian interaction with two rigid bodies will be studied. Taking advantage of the results obtained in previous papers, working on the reduced proble

Daniel B. Grunberg, Pieter Moree

We study the integer sequence v_n of numbers of lines in hypersurfaces of degree 2n-3 of P^n, n>1. We prove a number of congruence properties of these numbers of several different types. Furthermore, the asymptotics of the v_n are described (in an appendix by Don Zagier). An attempt is made at a similar analysis of two other enumerative sequences: the number

Fan Ding, Hansjörg Geiges

It has been shown by V. Colin that every tight contact 3-manifold can be written as a connected sum of prime manifolds. Here we prove that the summands in this decomposition are unique up to order and contactomorphism.

Bartlomiej Dyda, Tadeusz Kulczycki

We study the semigroup of the symmetric $α$-stable process in bounded domains in $\R^2$. We obtain a variational formula for the spectral gap, i.e. the difference between two first eigenvalues of the generator of this semigroup. This variational formula allows us to obtain lower bound estimates of the spectral gap for convex planar domains which are symmetri

Vadim Kostrykin, Konstantin A. Makarov, Anna Skripka

We introduce a relative index for a pair of dissipative operators in a von Neumann algebra of finite type and prove an analog of the Birman-Schwinger principle in this setting. As an application of this result, revisiting the Birman-Krein formula in the abstract scattering theory, we represent the de la Harpe-Skandalis determinant of the characteristic funct

Elemer E Rosinger

The essentials of a new method in solving very large classes of nonlinear systems of PDEs, possibly associated with initial and/or boundary value problems, are presented. The PDEs can be defined by continuous, not necessarily smooth expressions, and the solutions obtained cab be assimilated with usual measurable functions, or even with Hausdorff continuous o

Hjalmar Rosengren

We give a new proof of Milne&#39;s formulas for the number of representations of an integer as a sum of 4m^2 and 4m(m+1) squares. The proof is based on explicit evaluation of pfaffians with elliptic function entries, and relates Milne&#39;s formulas to Schur Q-polynomials and to correlation functions for continuous dual Hahn polynomials. We also state a new

Enric Nart, Christophe Ritzenthaler

We exhibit the isogeny classes of supersingular abelian threefolds over F_{2^n} containing the Jacobian of a genus 3 curve. In particular, we prove that for even n>6 there always exist a maximal and a minimal curve over F_{2^n}. All the curves can be obtained explicitly.

László Tóth

The integers $n=\prod_{i=1}^r p_i^{a_i}$ and $m=\prod_{i=1}^r p_i^{b_i}$ having the same prime factors are called exponentially coprime if $(a_i,b_i)=1$ for every $1\le i\le r$. We estimate the number of pairs of exponentially coprime integers $n,m\le x$ having the prime factors $p_1,...,p_r$ and show that the asymptotic density of pairs of exponentially cop

A. Ardizzoni, C. Menini, D. Stefan

We show that, under some mild conditions, a bialgebra in an abelian and coabelian braided monoidal category has a weak projection onto a formally smooth (as a coalgebra) sub-bialgebra with antipode; see Theorem 1.12. In the second part of the paper we prove that bialgebras with weak projections are cross product bialgebras; see Theorem 2.12. In the particula

Serge Cohen, Gennady Samorodnitsky

We describe a new class of self-similar symmetric $α$-stable processes with stationary increments arising as a large time scale limit in a situation where many users are earning random rewards or incurring random costs. The resulting models are different from the ones studied earlier both in their memory properties and smoothness of the sample paths.

Victor F. Araman, Peter W. Glynn

Consider a random walk $S=(S_n:n\geq 0)$ that is ``perturbed&#39;&#39; by a stationary sequence $(ξ_n:n\geq 0)$ to produce the process $(S_n+ξ_n:n\geq0)$. This paper is concerned with computing the distribution of the all-time maximum $M_{\infty}=\max \{S_k+ξ_k:k\geq0\}$ of perturbed random walk with a negative drift. Such a maximum arises in several differe

Peter Buergisser, Felipe Cucker, Martin Lotz

We prove a general theorem providing smoothed analysis estimates for conic condition numbers of problems of numerical analysis. Our probability estimates depend only on geometric invariants of the corresponding sets of ill-posed inputs. Several applications to linear and polynomial equation solving show that the estimates obtained in this way are easy to der

Ionut Ciocan-Fontanine, Bumsig Kim, Claude Sabbah

We propose an approach via Frobenius manifolds to the study (began in math.AG/0407254) of the relation between rational Gromov-Witten invariants of nonabelian quotients X//G and those of the corresponding ``abelianized&#39;&#39; quotients X//T, for T a maximal torus in G. The ensuing conjecture expresses the Gromov-Witten potential of X//G in terms of the po

Olaf M. Schnürer

This paper concerns regular connections on trivial algebraic G-principal fiber bundles over the infinitesimal punctured disc, where G is a connected reductive linear algebraic group over an algebraically closed field of characteristic zero. We show that the pull-back of every regular connection to an appropriate covering of the infinitesimal punctured disc i

Julia E. Bergner

In this paper we give a summary of the comparisons between different definitions of so-called (\infty,1)-categories, which are considered to be models for \infty-categories whose n-morphisms are all invertible for n>1. They are also, from the viewpoint of homotopy theory, models for the homotopy theory of homotopy theories. The four different structures, all

Dev P. Sinha

We develop a canonical pairing between trees and graphs, which passes to their quotients by Jacobi identities. This pairing is an effective and simple tool for understanding the Lie and Poisson operads, providing canonical duals. In the course of showing that this pairing is perfect we reprove some standard facts about the modules Lie(n), establishing standa

Don N. Page

Evidence for fine-tuning of physical parameters suitable for life can perhaps be explained by almost any combination of providence, coincidence or multiverse. A multiverse usually includes parts unobservable to us, but if the theory for it includes suitable measures for observations, what is observable can be explained in terms of the theory even if it conta

Luigi Del Debbio, Gian Mario Manca, Haralambos Panagopoulos, Apostolos Skouroupathis

We study the theta dependence of the spectrum of four-dimensional SU(N) gauge theories, where theta is the coefficient of the topological term in the Lagrangian, for N>=3 and in the large-N limit. We compute the O(theta^2) terms of the expansions around theta=0 of the string tension and the lowest glueball mass, respectively sigma(theta) = sigma (1 + s_2 the

Ali H. Chamseddine

A generalized theory unifying gravity with electromagnetism was proposed by Einstein in 1945. He considered a Hermitian metric on a real space-time. In this work we review Einstein&#39;s idea and generalize it further to consider gravity in a complex Hermitian space-time.

Victor O. Rivelles

Applying a master action technique we obtain the dual of the noncommutative Maxwell-Chern-Simons theory. The equivalence between the Maxwell-Chern-Simons theory and the self-dual model in commutative space-time does not survive in the non-commutative setting. We also point out an ambiguity in the Seiberg-Witten map.

Christoph A. Stephan

In recent publications Alain Connes [1] and John Barrett [2] proposed to change the KO-dimension of the internal space of the standard model in its noncommutative representation [3] from zero to six. This apparently minor modification allowed to resolve the fermion doubling problem [4], and the introduction of Majorana mass terms for the right-handed neutrin

B. Piette, W. J. Zakrzewski

We analyse the scattering of a two-dimensional soliton on a potential well. We show that this soliton can pass through the well, bounce back or become trapped and we study the dependence of the critical velocity on the width and the depth of the well. We also present a model based on a pseudo-geodesic approximation to the full system which shows that the vib

Giuseppe Vitiello

In this report I review some aspects of the algebraic structure of QFT related with the doubling of the degrees of freedom of the system under study. I show how such a doubling is related to the characterizing feature of QFT consisting in the existence of infinitely many unitarily inequivalent representations of the canonical (anti-)commutation relations and