March 2006 arXiv papers — page 27

Raphael Bousso, Ben Freivogel, Matthew Lippert

We discuss aspects of the problem of assigning probabilities in eternal inflation. In particular, we investigate a recent suggestion that the lowest energy de Sitter vacuum in the landscape is effectively stable. The associated proposal for probabilities would relegate lower energy vacua to unlikely excursions of a high entropy system. We note that it would

Angelica de Oliveira-Costa, Max Tegmark

Most analysis of Cosmic Microwave Background spherical harmonic coefficients a_lm has focused on estimating the power spectrum C_l=<|a_lm|^2> rather than the coefficients themselves. We present a minimum-variance method for measuring a_lm given anisotropic noise, incomplete sky coverage and foreground contamination, and apply it to the WMAP data. Our method

V. Derr, D. Kinzebulatov

As follows from the Schwartz Impossibility Theorem, multiplication of two distributions is in general impossible. Nevertheless, often one needs to multiply a distribution by a discontinuous function, not by an arbitrary distribution. In the present paper we construct a space of distributions where the general operation of multiplication by a discontinuous fu

Ciamac C. Moallemi, Benjamin Van Roy

We establish the convergence of the min-sum message passing algorithm for minimization of a broad class of quadratic objective functions: those that admit a convex decomposition. Our results also apply to the equivalent problem of the convergence of Gaussian belief propagation.

M. Carena, A. Menon, R. Noriega-Papaqui, A. Szynkman

We study the implications of minimal flavor violating low energy supersymmetry scenarios for the search of new physics in the B and Higgs sectors at the Tevatron collider and the LHC. We show that the already stringent Tevatron bound on the decay rate B_s -> mu+ mu- sets strong constraints on the possibility of generating large corrections to the mass differ

J. Harnad, A. Yu. Orlov

We give a new method for the evaluation of a class of integrals of rational symmetric functions in N pairs of variables {x_a, y_a}_{a=1,... N} arising in coupled matrix models, valid for a broad class of two-variable measures. The result is expressed as the determinant of a matrix whose entries consist of the associated biorthogonal polynomials, their Hilber

B. McKinnon, K. Hicks

A search for the \thp in the reaction $γd \to pK^-K^+n$ was completed using the CLAS detector at Jefferson Lab. A study of the same reaction, published earlier, reported the observation of a narrow \thp resonance. The present experiment, with more than 30 times the integrated luminosity of our earlier measurement, does not show any evidence for a narrow pent

Erin De Pree, Marc Sher

If the lowest lying Kaluza-Klein states in Randall-Sundrum (RS1) models have masses in the 10-100 TeV range, direct production of these states at the LHC or ILC is impossible, and electroweak precision measurements may not be sufficiently sensitive. We address the possibility that high-precision measurements of top pair production at the ILC may provide the

D. E. Alvarez-Castillo, M. Kirchbach

The exact solutions of the Schrodinger equation with the hyperbolic Scarf potential reported in the literature so far rely upon Jacobi polynomials with imaginary arguments and parameters. We here show that upon a suitable factorization these solutions can be expressed alternatively by means of real orthogonal polynomials distinct but the classical ones as th

Thomas Appelquist, Yang Bai, Maurizio Piai

We explore a framework for the computation of quark mass ratios and CKM mixing angles based on an SU(3) family gauge symmetry. The four ratios md/mb, ms/mb, mu/mt, and mc/mt can be fit at one-loop in the family gauge interaction. The same is true of the quark mixing angles theta12 and theta23, although the result for theta13 is too small. The CP violating ph

Philip M. Davis, Michael J. Fromerth

An analysis of 2,765 articles published in four math journals from 1997 to 2005 indicate that articles deposited in the arXiv received 35% more citations on average than non-deposited articles (an advantage of about 1.1 citations per article), and that this difference was most pronounced for highly-cited articles. Open Access, Early View, and Quality Differe

Bert Schroer

This essay presents a critical evaluation of the concepts of string theory and its impact on particle physics. The point of departure is a historical review of four decades of string theory within the broader context of six decades of failed attempts at an autonomous S-matrix approach to particle theory. The central message, contained in sections 5 and 6, is

Jerrold Franklin

The absence of any tendency toward rotation in the Trouton-Noble experiment is given a simple explanation.

J. Gomez-Torrecillas

Starting from a comonad G on a category A, and a functor L : B -> A with a right adjoint R : A -> B, we will give a parametrization of the functors K from B to the category of all G-coalgebras that factorize throughout L in terms of homomorphisms of comonads from LR to G. Next, we will see under which conditions one of these functors K admits a right adjoint

Robson B. Rodrigues, Paulo A. Maia Neto, Astrid Lambrecht, Serge Reynaud

We argue that the appropriate variable to study a non trivial geometry dependence of the Casimir force is the lateral component of the Casimir force, which we evaluate between two corrugated metallic plates outside the validity of the Proximity Force Approximation (PFA). The metallic plates are described by the plasma model, with arbitrary values for the pla

Gad Naot

We determine the algebraic structure underlying the geometric complex associated to a link in Bar-Natan&#39;s geometric formalism of Khovanov&#39;s link homology theory (n=2). We find an isomorphism of complexes which reduces the complex to one in a simpler category. This reduction enables us to specify exactly the amount of information held within the geome

Vladimir Retakh, Shirlei Serconek, Robert Lee Wilson

This is a survey of recently published results. We introduce and study a wide class algebras associated to directed graphs and related to factorizations of noncommutative polynomials. In particular, we show that for many well-known graphs such algebras are Koszul and compute their Hilbert series.

O. Bertolami, V. Duvvuri

We discuss chaotic inflation in the context of a phenomenological modification of gravity inspired by the Chaplygin gas equation of state. We find that all observationalconstraints can be satisfied provided the Chaplygin scale is smaller than $6.9 \times 10^{-3} M$ and the inflaton mass is smaller than $4.7 \times 10^{-6} M$, respectively, where $M^2\equiv(8

Eric Cator, Piet Groeneboom

We show that, for a stationary version of Hammersley&#39;s process, with Poisson sources on the positive x-axis and Poisson sinks on the positive y-axis, the variance of the length of a longest weakly North--East path $L(t,t)$ from $(0,0)$ to $(t,t)$ is equal to $2\mathbb {E}(t-X(t))_+$, where $X(t)$ is the location of a second class particle at time $t$. Th

Giovanni Diana, Nicola Manini, Luca Salasnich

We study the free expansion of a dilute two-component Fermi gas with attractive interspecies interaction in the BCS-BEC crossover. We apply a time-dependent parameter-free density-functional theory by using two choices of the equation of state: an analytic formula based on Monte Carlo data and the mean-field equation of state resulting from the extended BCS

J. P. Cotter, B. Varcoe

A test of Lorentz invariance has been performed using an EIT resonance as a precision frequency discriminator within an Ives-Stilwell like apparatus. We analyse the experiment within the framework of the Standard Model Extension and have made the first direct measurment of the parameter $κ_{tr}<1.6\times10^{-5}$.

I. Masina, C. A. Savoy

Prompted by the recent better determination of the angles of the unitarity triangle, we re-appraise the problem of finding simple fermion mass textures, possibly linked to some symmetry principle and compatible with grand unification. In particular, the indication that the angle alpha is close to rectangle turns out to be the crucial ingredient leading us to

Gianmarco Capitanio, Andre Diatta

Mark all vertices on a curve evolving under a family of curves obtained by intersecting a smooth surface M with the 1-parameter family of planes parallel to the tangent plane to M at a point p. Those vertices trace out a set, called the vertex set of M through p. We take p to be an isolated umbilic point on M and describe the perestroikas of the vertex set u

D. Benedetti, R. Loll

We propose a novel way of investigating the universal properties of spin systems by coupling them to an ensemble of causal dynamically triangulated lattices, instead of studying them on a fixed regular or random lattice. Somewhat surprisingly, graph-counting methods to extract high- or low-temperature series expansions can be adapted to this case. For the tw

C. M. Raiteri, M. Villata, M. Kadler, T. P. Krichbaum

In this paper we analyse five observations of the BL Lac object AO 0235+16 performed with the Chandra and XMM-Newton satellites during the years 2000-2005. In the February 2002 observation the source is found in a bright state and presents a steep X-ray spectrum, while in all the other epochs it is faint and the spectrum is hard. The soft X-ray spectrum appe

Fulvio Baldovin, Enzo Orlandini

We introduce a Hamiltonian dynamics for the description of long-range interacting systems in contact with a thermal bath (i.e., in the canonical ensemble). The dynamics confirms statistical mechanics equilibrium predictions for the Hamiltonian Mean Field model and the equilibrium ensemble equivalence. We find that long-lasting quasi-stationary states persist

Abhas Mitra

Even when we consider Newtonian stars, i.e., stars with surface gravitational redshift, z<< 1, it is well known that, theoretically, it is possible to have stars, supported against self-gravity, almost entirely by radiation pressure. However, such Newtonian stars must necessarily be supermassive. We point out that this requirement for excessive large M, in N

Eugene H. Avrett, Robert L. Kurucz, Rudolf Loeser

Wilhelm et al. have recently called attention to the unidentified broad emission features near 117 nm in the solar spectrum. They discuss the observed properties of these features in detail but do not identify the source of this emission. We show that the broad autoionizing transitions of neutral sulfur are responsible for these emission features. Autoionizi

David Berenstein

This paper studies the compatibility of having a grand unification scheme for particle physics, while at the same time having a perturbative string theory description of such a scheme on a D-brane. This is studied in a model independent approach and finds a negative result. Some additional observations related to model building on branes are made.

Mauro Sellitto

A disordered spin model suitable for studying inverse freezing in fragile glass-forming systems is introduced. The model is a microscopic realization of the ``random-first order&#39;&#39; scenario in which the glass transition can be either continuous or discontinuous in thermodynamic sense. The phase diagram exhibits a first-order transition line between tw

T. Jungwirth, Jairo Sinova, J. Masek, J. Kucera

The body of research on (III,Mn)V diluted magnetic semiconductors initiated during the 1990&#39;s has concentrated on three major fronts: i) the microscopic origins and fundamental physics of the ferromagnetism that occurs in these systems, ii) the materials science of growth and defects and iii) the development of spintronic devices with new functionalities

Anastasia Doikou

The generalized open XXZ model at $q$ root of unity is considered. We review how associated models, such as the $q$ harmonic oscillator, and the lattice sine-Gordon and Liouville models are obtained. Explicit expressions of the local Hamiltonian of the spin ${1 \over 2}$ XXZ spin chain coupled to dynamical degrees of freedom at the one end of the chain are p

Olivier Renaudin

We construct a pseudo-localization of the 2-category of combinatorial Quillen model categories with respect to Quillen equivalences, and then verify that it embeds in a 2-category of Grothendieck derivators.

CDF Collaboration, A. Abulencia

We present a measurement of the B_c+ meson lifetime in the semileptonic decay mode Bc+ ->J/Psi e+ nu using the CDF II detector at the Fermilab Tevatron Collider. From a sample of about 360pb-1 p-pbar collisions at sqrt(s)=1.96TeV, we reconstruct J/Psi e+ pairs with invariant mass in the kinematically allowed range 4<M(J/Psi e)<6GeV/c^2. A fit to the decay-le

Joerg Schuermann, Mihai Tibar

We give explicit MacPherson cycles for the Chern-MacPherson class of a closed affine algebraic variety $X$ and for any constructible function $α$ with respect to a complex algebraic Whitney stratification of $X$. We define generalized degrees of the global polar varieties and of the MacPherson cycles and we prove a global index formula for the Euler characte

V. Josse, M. Sabuncu, N. J. Cerf, G. Leuchs

We propose and experimentally realize a new scheme for universal phase-insensitive optical amplification. The presented scheme relies only on linear optics and homodyne detection, thus circumventing the need for nonlinear interaction between a pump field and the signal field. The amplifier demonstrates near optimal quantum noise limited performance for a wid

M. Juvela, V. -M. Pelkonen, P. Padoan, K. Mattila

With current wide-field near-infrared (NIR) instruments the scattered light in the near-infrared can be mapped over large areas. Below A_V ~ 10 the surface brightness is directly proportional to the column density, and at slightly higher column densities the saturation of the intensity values can be corrected using the ratios of the intensity in different NI

Roy Maartens, Elisabetta Majerotto

The DGP brane-world model provides a simple alternative to the standard LCDM cosmology, with the same number of parameters. There is no dark energy - the late universe self-accelerates due to an infrared modification of gravity. We compute the joint constraints on the DGP model from supernovae, the cosmic microwave background shift parameter, and the baryon

Sergio Ferrara, Oscar Macia

We consider a formulation of local special geometry in terms of Darboux special coordinates $P^I=(p^i,q_i)$, $I=1,...,2n$. A general formula for the metric is obtained which is manifestly $\mathbf{Sp}(2n,\mathbb{R})$ covariant. Unlike the rigid case the metric is not given by the Hessian of the real function $S(P)$ which is the Legendre transform of the imag

Ken&#39;ichi Nomoto, Hideyuki Saio, Mariko Kato, Izumi Hachisu

We revisit the properties of white dwarfs accreting hydrogen-rich matter by constructing steady-state models, in which hydrogen shell burning consumes hydrogen at the same rate as the white dwarf accretes it. We obtain such steady-state models for various accretion rates and white dwarf masses. We confirm that these steady models are thermally stable only wh

Shinji Hirano

We found a simple and interesting generalization of the non-supersymmetric Janus solution in type IIB string theory. The Janus solution can be thought of as a thick AdS_d-sliced domain wall in AdS_{d+1} space. It turns out that the AdS_d-sliced domain wall can support its own AdS_{d-1}-sliced domain wall within it. Indeed this pattern persists further until

Jens Eisert, Tobias J. Osborne

We establish a general scaling law for the entanglement of a large class of ground states and dynamically evolving states of quantum spin chains: we show that the geometric entropy of a distinguished block saturates, and hence follows an entanglement-boundary law. These results apply to any ground state of a gapped model resulting from dynamics generated by

François Gay-Balmaz, Tudor S. Ratiu

This paper presents the theory of non-smooth Lie group actions on chains of Banach manifolds. The rigorous functional analytic spaces are given to deal with quotients of such actions. A hydrodynamical example is studied in detail.

Milan Krbalek

We derive the exact formula for thermal-equilibrium spacing distribution of one-dimensional particle gas with repulsive potential V(r)=r^(-a) (a>0) depending on the distance r between the neighboring particles. The calculated distribution (for a=1) is successfully compared with the highway-traffic clearance distributions, which provides a detailed view of ch

A. Cano, A. P. Levanyuk

We comment on zero- and low-temperature structural phase transitions, expecting that these comments might be relevant not only for this structural case. We first consider a textbook model whose classical version is the only model for which the Landau theory of phase transitions and the concept of ``soft mode&#39;&#39; introduced by Ginzburg are exact. Within

Stan Zachary, Sergey Foss

We study the distribution of the maximum $M$ of a random walk whose increments have a distribution with negative mean and belonging, for some $γ>0$, to a subclass of the class $\mathcal{S}_γ$--see, for example, Chover, Ney, and Wainger (1973). For this subclass we give a probabilistic derivation of the asymptotic tail distribution of $M$, and show that extre

Joop J. Gilijamse, Jochen Küpper, Steven Hoekstra, Nicolas Vanhaecke

We demonstrate feedback control optimization for the Stark deceleration and trapping of neutral polar molecules using evolutionary strategies. In a Stark-decelerator beamline pulsed electric fields are used to decelerate OH radicals and subsequently store them in an electrostatic trap. The efficiency of the deceleration and trapping process is determined by

Tsuguchika Tabaru

Single electrons from open heavy quarks and di-leptons from J/psi mesons have been studied systematically at RHIC/PHENIX using data from p + p, d + Au and Au + Au collisions at $\sqrt{s_{NN}}$ = 62.4 GeV, 130 GeV and 200 GeV. From the single electron study, the charm quark yield is found to scale with the number of binary collisions. This scaling has recentl

Asaf Pe&#39;er, Peter Mészáros, Martin J. Rees

Observations of early afterglow emission from gamma-ray bursts (GRB&#39;s) with the Swift satellite show steep decay of the X-ray light curve, F_ν(t) ~ t^{-α} with α~ 2.5 - 4 at ~300-500 s after the burst trigger. The spectrum in this time interval is consistent with a spectrum F_ν~ ν^{-β} with β~1. Here, we show that these results can be explained as due to

H. Nakada, K. Tanabe

We formulate a new Bardeen-Cooper-Schrieffer (BCS)-type theory at finite temperature, by deriving a set of variational equations of the free energy after the particle-number projection. With its broad applicability, this theory can be a useful tool for investigating the pairing phase transition in finite systems with the particle-number conservation. This th

Jonas Kahn

In a recent paper, Buscemi and al. defined a notion of clean positive operator valued measures (POVMs). We here characterize which POVMs are clean in some class that we call quasi-qubit POVMs, namely POVMs whose elements are all rank-one or full-rank. We give an algorithm to check whether a given quasi-qubit POVM satisfies to this condition. We describe expl

Marcelo Sobottka

In this paper we consider cellular automata $(\mathfrak{G},Φ)$ with algebraic local rules and such that $\mathfrak{G}$ is a topological Markov chain which has a structure compatible to this local rule. We characterize such cellular automata and study the convergence of the Cesàro mean distribution of the iterates of any probability measure with complete conn

Gunnar Martens, Carsten Greiner, Stefan Leupold, Ulrich Mosel

We investigate 4-quark ($qq\bar{q}\bar{q}$) systems as well as multi-quark states with a large number of quarks and anti-quarks using the chromodielectric model. In the former type of systems the flux distribution and the corresponding energy of such systems for planar and non-planar geometries are studied. From the comparison to the case of two independent

Nan Zhao, L. Zhong, Jia-Lin Zhu, C. P. Sun

We theoretically explore the possibility of creating spin quantum entanglement in a system of two electrons confined respectively in two vertically coupled quantum dots in the presence of Rashba type spin-orbit coupling. We find that the system can be described by a generalized Jaynes - Cummings model of two modes bosons interacting with two spins. The lower

Steffen Roch, Bernd Silbermann

The classical Szegö theorems study the asymptotic behaviour of the determinants of the finite sections $P_n T(a) P_n$ of Toeplitz operators, i.e., of operators which have constant entries along each diagonal. We generalize these results to operators which have almost periodic functions on their diagonals.

O. G. Chkhetiani, M. Hnatič, E. Jurcisinova, M. Jurcisin

The influence of helicity on the stability of scaling regimes, on the effective diffusivity, and on the anomalous scaling of structure functions of a passive scalar advected by a Gaussian solenoidal velocity field with finite correlation time is investigated by the field theoretic renormalization group and operator product expansion within two-loop approxima

Yu Kawakami

In this paper, we prove effective estimates for the number of exceptional values and the totally ramified value number for the Gauss map of pseudo-algebraic minimal surfaces in Euclidean four-space and give a kind of unicity theorem.

X. W. Shu, J. X. Wang, P. Jiang, L. L. Fan

We build a large sample of Seyfert 2 galaxies (Sy2s) with both optical spectropolarimetric and X-ray data available, in which 29 Sy2s with the detection of polarized broad emission line (PBL) and 25 without. We find that for luminous Sy2s with L_[OIII] > 10^41 erg/s, sources with PBL have smaller X-ray absorption column density comparing with those without P

T. Tabaru, H. En&#39;yo, R. Muto, M. Naruki

The inclusive production of omega and phi mesons is studied in the backward region of the interaction of 12 GeV protons with polyethylene, carbon, and copper targets. The mesons are measured in e^+ e^- decay channels. The production cross sections of the mesons are presented as functions of rapidity y and transverse momentum p_T. The nuclear mass number depe

Yanbei Chen, Archana Pai, Kentaro Somiya, Seiji Kawamura

We propose a class of displacement- and laser-noise free gravitational-wave-interferometer configurations, which does not sense non-geodesic mirror motions and laser noises, but provides non-vanishing gravitational-wave signal. Our interferometer consists of 4 mirrors and 2 beamsplitters, which form 4 Mach-Zehnder interferometers. By contrast to previous wor

Maxim Kontsevich, Albert Schwarz, Vadim Vologodsky

We study integrality of instanton numbers (genus zero Gopakumar - Vafa invariants) for quintic and other Calabi-Yau manifolds. We start with the analysis of the case when the moduli space of complex structures is one-dimensional; later we show that our methods can be used to prove integrality in general case. We give an expression of instanton numbers in ter

Paolo Albano, Antonio Bove, David S. Tartakoff

We consider a second order operator with analytic coefficients whose principal symbol vanishes exactly to order two on a symplectic real analytic manifold. We assume that the first (non degenerate) eigenvalue vanishes on a symplectic submanifold of the characteristic manifold. In the $C^\infty$ framework this situation would mean a loss of 3/2 derivatives. W

Alejandro Ayala, Eleazar Cuautle, J. Magnin, Luis Manuel Montano

We show that the proton and pion transverse momentum distributions measured at RHIC for all collision centralities for pions and most of the collision centralities for protons, can be simultaneously described in terms of a thermal model with common values for the radial flow and temperature, when accounting for the finite size of the interaction region at th

Masataka Fukugita, Masahiro Kawasaki

A reanalysis is made for the helium abundance determination for the Izotov-Thuan (2004) spectroscopic sample of extragalactic H II regions. We find that the effect of underlying stellar absorption of the He I lines, which is more important for metal poor systems, affects significantly the inferred primordial helium abundance $Y_p$ obtained in the zero metall

Emil J. Martinec, Daniel Robbins, Savdeep Sethi

The null-brane space-time provides a simple model of a big crunch/big bang singularity. A non-perturbative definition of M-theory on this space-time was recently provided using matrix theory. We derive the fermion couplings for this matrix model and study the leading quantum effects. These effects include particle production and a time-dependent potential. O

C. Bernard

Staggered chiral perturbation theory (schpt) takes into account the &#34;fourth-root trick&#34; for reducing unwanted (taste) degrees of freedom with staggered quarks by multiplying the contribution of each sea quark loop by a factor of 1/4. In the special case of four staggered fields (four flavors, nF=4), I show here that certain assumptions about analytic

M. H. Albert, M. D. Atkinson, Robert Brignall

A pattern class is a set of permutations closed under the formation of subpermutations. Such classes can be characterised as those permutations not involving a particular set of forbidden permutations. A simple collection of necessary and sufficient conditions on sets of forbidden permutations which ensure that the associated pattern class is of polynomial g

Andrew R Francis, John J Graham

In this paper we prove the Dipper-James conjecture that the centre of the Iwahori-Hecke algebra of type A is the set of symmetric polynomials in the Jucys-Murphy operators.

E. Figueroa, F. Vewinger, J. Appel, A. I. Lvovsky

We report characterization of electromagnetically induced transparency (EIT) resonances in the D1 line of Rb-87 under various experimental conditions. The dependence of the EIT linewidth on the power of the pump field was investigated, at various temperatures, for the ground states of the lambda-system associated with different hyperfine levels of the atomic

Josep Batle-Vallespir

The present Thesis covers the subject of the characterization of entangled states by recourse to entropic measures, as well as the description of entanglement related to several issues in quantum mechanics, such as the speed of a quantum evolution or the connections existing between quantum entanglement and quantum phase transitions.

S. Bravyi, M. B. Hastings, F. Verstraete

The Lieb-Robinson bound states that local Hamiltonian evolution in nonrelativistic quantum mechanical theories gives rise to the notion of an effective light-cone with exponentially decaying tails. We discuss several consequences of this result in the context of quantum information theory. First, we show that the information that leaks out to space-like sepa

Tal Mor, Nadav Yoran

We propose a scalable method for implementing linear optics quantum computation using the ``linked-state&#39;&#39; approach. Our method avoids the two-dimensional spread of errors occurring in the preparation of the linked-state. Consequently, a proof is given for the scalability of this modified linked-state model, and an exact expression for the efficiency

Robin Blume-Kohout, Patrick Hayden

In this article, we derive a unique procedure for quantum state estimation from a simple, self-evident principle: an experimentalist&#39;s estimate of the quantum state generated by an apparatus should be constrained by honesty. A skeptical observer should subject the estimate to a test that guarantees that a self-interested experimentalist will report the t

Sun Hong Rhie

The new camera system of the shuttle Discovery on STS-114 that blasted off at 10:39am, Tuesday, July 26, 2005, after 906 days of grounding since the Columbia accident, has produced high resolution data of foam sheddings. The 0.9 lbs piece from the Protuberance Air Load (PAL) ramp on the LH2 tank is believed to be comparable in its potential adversities to th

Marc G. Millis

Gauging the benefits of hypothetical gravity control propulsion is difficult, but addressable. The major challenge is that such breakthroughs are still only notional concepts rather than being specific methods from which performance can be rigorously quantified. A recent assessment by Tajmar and Bertolami used the rocket equation to correct naive misconcepti

J. Mitroy

Close to converged energies and expectation values for PsH are computed using a ground state wave function consisting of 1800 explicitly correlated gaussians. The best estimate of the PsH$^{\infty}$ energy was -0.789196740 hartree which is the lowest variational energy to date. The 2$γ$ annihilation rate for PsH$^{\infty}$ was $2.47178\times 10^{9}$ s$^{-1}$

S. Schneider, S. Krewald, Ulf-G. Meißner

A resonance model for two-pion production in the pion-nucleon reaction is developed that includes information obtained in the analysis of pion-nucleon scattering in a meson-exchange model. The baryonic resonances Delta(1232), N*(1440), N*(1520), N*(1535), and N*(1650) are included. The model reproduces the total cross sections up to kinetic energies of the i

A. Obertelli, A. Gade, D. Bazin, C. M. Campbell

Fragmentation reactions with intermediate-energy heavy-ion beams exhibit a wide range of reaction mechanisms, ranging from direct reactions to statistical processes. We examine this transition by measuring the relative population of excited states in several sd-shell nuclei produced by fragmentation with the number of removed nucleons ranging from two to six

Georg A. Gottwald, Lorenz Kramer

We present a normal form for travelling waves in one-dimensional excitable media in form of a differential delay equation. The normal form is built around the well-known saddle-node bifurcation generically present in excitable media. Finite wavelength effects are captured by a delay. The normal form describes the behaviour of single pulses in a periodic doma

Antti Kupiainen, Paolo Muratore-Ginanneschi

We present a systematic way to compute the scaling exponents of the structure functions of the Kraichnan model of turbulent advection in a series of powers of $ξ$, adimensional coupling constant measuring the degree of roughness of the advecting velocity field. We also investigate the relation between standard and renormalization group improved perturbation

Nalini Joshi, Kenji Kajiwara, Marta Mazzocco

We consider a Hankel determinant formula for generic solutions of the Painlevé IV equation. We show that the generating functions for the entries of the Hankel determinants are related to the asymptotic solution at infinity of the isomonodromic problem. Summability of these generating functions are also discussed.

K. Ebrahimi-Fard, L. Guo, D. Manchon

We describe a unification of several apparently unrelated factorizations arisen from quantum field theory, vertex operator algebras, combinatorics and numerical methods in differential equations. The unification is given by a Birkhoff type decomposition that was obtained from the Baker-Campbell-Hausdorff formula in our study of the Hopf algebra approach of C

Alexander Kirillov

Let $G$ be a finite subgroup in SU(2), and $Q$ the corresponding affine Dynkin diagram. In this paper, we review the relation between the categories of $G$-equivariant sheaves on $P^1$ and $Rep Q_h$, where $h$ is an orientation of $Q$, constructing an explicit equivalence of corresponding derived categories.

Aleksey Zinger

We give two recursions for computing top intersections of tautological classes on blowups of moduli spaces of genus-one curves. One of these recursions is analogous to the well-known string equation. As shown in previous papers, these numbers are useful for computing genus-one enumerative invariants of projective spaces and Gromov-Witten invariants of comple

Thierry Monteil, Solomon Marcus

An infinite word x is said to be quasiperiodic if there exists a finite word q such that x is covered by occurrences of q (such a q is called a quasiperiod of x). Using the notion of derivation, we show that this definition is not sufficient to imply any symmetry in an infinite word. Therefore we introduce multi-scale quasiperiodic words, i.e. quasiperiodic

Thierry Monteil

We prove that, for translation surfaces whose homology is generated by the periodic orbits, the notions of - finite blocking property - pure periodicity - torus branched covering are equivalent. In particular, we prove this equivalence for convex surfaces and on a dense open subset of full measure on every normalized stratum.

Eric Leichtnam, Xiang Tang, Alan Weinstein

Let X be a complex manifold with strongly pseudoconvex boundary M. If u is a defining function for M, then -log u is plurisubharmonic on a neighborhood of M in X, and the (real) 2-form s = i \del \delbar(-log u) is a symplectic structure on the complement of M in a neighborhood in X of M; it blows up along M. The Poisson structure obtained by inverting s ext

Pierre Alquier

In a previous article, a least square regression estimation procedure was proposed: first, we condiser a family of functions and study the properties of an estimator in every unidimensionnal model defined by one of these functions; we then show how to aggregate these estimators. The purpose of this paper is to extend this method to the case of density estima

Szilard Gy. Revesz, Noli N. Reyes, Gino Angelo M. Velasco

Under certain conditions on an integrable function f having a real-valued Fourier transform Tf=F, we obtain a certain estimate for the oscillation of F in the interval [-C||f&#39;||/||f||,C||f&#39;||/||f||] with C>0 an absolute constant. Given q>0 and an integrable positive definite function f, satisfying some natural conditions, the above estimate allows us

Gerard Ben Arous, Jiri Cerny

These notes cover one of the topics of the class given in the Les Houches Summer School ``Mathematical statistical physics&#39;&#39; in July 2005. The lectures tried to give a summary of the recent mathematical results about the long-time behaviour of dynamics of (mean-field) spin-glasses and other disordered media. We have chosen here to restrict the scope

Michael McLendon

For a surface $F$, the Kauffman bracket skein module of $F \times [0,1]$, denoted $K(F)$, admits a natural multiplication which makes it an algebra. When specialized at a complex number $t$, nonzero and not a root of unity, we have $K_t(F)$, a vector space over $\mathbb{C}$. In this paper, we will use the product-to-sum formula of Frohman and Gelca to show t

Jirô Akahori

This is a survey note of the author&#39;s observations on the discrete-time analogues of Itô formulas.

Gerard Ben Arous, Jiri Cerny

We give a general proof of aging for trap models using the arcsine law for stable subordinators. This proof is based on abstract conditions on the potential theory of the underlying graph and on the randomness of the trapping landscape. We apply this proof to aging for trap models on large two-dimensional tori and for trap dynamics of the Random Energy Model

David Coupier, Agnès Desolneux, Bernard Ycart

Area openings and closings are morphological filters which efficiently suppress impulse noise from an image, by removing small connected components of level sets. The problem of an objective choice of threshold for the area remains open. Here, a mathematical model for random images will be considered. Under this model, a Poisson approximation for the probabi

Ben Walter

This is a (slightly edited) version of the PhD dissertation of the author, submitted to Brown University in July 2005. We construct a homotopy calculus of functors in the sense of Goodwillie for the categories of rational homotopy theory. More precisely, given a homotopy functor between any of the categories of differential graded vector spaces (DG), reduced

N. Lanchier, C. Neuhauser

Mutualists and pathogens, collectively called symbionts, are ubiquitous in plant communities. While some symbionts are highly host-specific, others associate with multiple hosts. The outcomes of multispecies host-symbiont interactions with different degrees of specificity are difficult to predict at this point due to a lack of a general conceptual framework.

Deli Li, Andrew Rosalsky

Let $\{X_{k,i};i\geq 1,k\geq 1\}$ be an array of i.i.d. random variables and let $\{p_n;n\geq 1\}$ be a sequence of positive integers such that $n/p_n$ is bounded away from 0 and $\infty$. For $W_n=\max_{1\leq i<j\leq p_n}|\sum_{k=1}^nX_{k,i}X_{k,j}|$ and $L_n=\max_{1\leq i<j\leq p_n}|\hatρ^{(n)}_{i,j}|$ where $\hatρ^{(n)}_{i,j}$ denotes the Pearson correlat

David Coupier, Agnès Desolneux, Bernard Ycart

For an $n\times n$ random image with independent pixels, black with probability $p(n)$ and white with probability $1-p(n)$, the probability of satisfying any given first-order sentence tends to 0 or 1, provided both $p(n)n^{\frac{2}{k}}$ and $(1-p(n))n^{\frac{2}{k}}$ tend to 0 or $+\infty$, for any integer $k$. The result is proved by computing the threshold

L. Belhadji, N. Lanchier

Stochastic modeling of disease dynamics has had a long tradition. Among the first epidemic models including a spatial structure in the form of local interactions is the contact process. In this article we investigate two extensions of the contact process describing the course of a single disease within a spatially structured human population distributed in s

Li-X. Zhang, Feifang Hu, Siu Hung Cheung

The Generalized Pólya Urn (GPU) is a popular urn model which is widely used in many disciplines. In particular, it is extensively used in treatment allocation schemes in clinical trials. In this paper, we propose a sequential estimation-adjusted urn model (a nonhomogeneous GPU) which has a wide spectrum of applications. Because the proposed urn model depends