April 2006 arXiv papers — page 25

Jean-François Coeurjolly, Rémy Drouilhet, Jean-François Robineau

This paper is devoted to the mathematical study of some divergences based on the mutual information well-suited to categorical random vectors. These divergences are generalizations of the "entropy distance" and "information distance". Their main characteristic is that they combine a complexity term and the mutual information. We then introduc

David Brander

We define a large class of integrable nonlinear PDE's, \emph{$k$-symmetric AKS systems}, whose solutions evolve on finite dimensional subalgebras of loop algebras, and linearize on an associated algebraic curve. We prove that periodicity of the associated algebraic data implies a type of quasiperiodicity for the solution, and show that the problem of iso

J. M. Luck, C. Godreche

We construct explicit examples of one-dimensional driven diffusive systems for two and three species of interacting particles, defined by asymmetric dynamical rules which do not obey detailed balance, but whose nonequilibrium stationary-state measure coincides with a prescribed equilibrium Gibbs measure. For simplicity, the measures considered in this constr

R. Gerritsma, R. J. C. Spreeuw

We theoretically investigate properties of magnetostatic traps for cold atoms that are subject to externally applied uniform fields. We show that Ioffe Pritchard traps and other stationary points of $B$ are confined to a two-dimensional curved manifold defined by $\det(\partial B_i/\partial x_j)=0$. We describe how stationary points can be moved over the man

Hua-Hui Xiong, Jian-Yang Zhu

In loop quantum cosmology nonperturbative modification to a scalar matter field at short scales implies inflation which also means a violation of the strong energy condition. In the framework of effective Hamiltonian we discuss the issue of violation of the strong energy condition in the presence of quantum geometry potential. It shows that the appearance of

G. A. Q. Salvati, L. G. Suttorp

The collective-mode spectrum of a multicomponent magnetized ionic mixture for small wave number k is studied with the use of magnetohydrodynamics and formal kinetic theory. Apart from the usual thermal and diffusive modes, the spectrum contains a set of four oscillating modes. By evaluating the k^2 contributions to the eigenfrequencies, the damping and the d

Tien-Yu Peter Chern

It is proved that for any positive number $λ$, $1<λ<2$; there exists a meromorphic function $f$ with logarithmic order $λ$= $\displaystyle\limsup_{r\to+\infty}\frac{\log T(r,f)}{\log\log r}$ such that $f$ has no Julia directions, where $T(r,f)$ is the Nevanlinna characteristic function of $f$. (Note that A. Ostrowski has proved a {\it similar} result for $λ=

M. I. Krivoruchenko, Amand Faessler

The knowledge of quantum phase flow induced under the Weyl&#39;s association rule by the evolution of Heisenberg operators of canonical coordinates and momenta allows to find the evolution of symbols of generic Heisenberg operators. The quantum phase flow curves obey the quantum Hamilton&#39;s equations and play the role of characteristics. At any fixed leve

J. H. Field

A detailed study is made of the space-time transformation properties of intercharge forces and the associated electric and magnetic force fields, both in classical electrodynamics and in a recently developed relativistic classical electrodynamical theory. Important differences are found and serious errors are found in the traditional treatment of special-rel

B. A. Danilchenko, T. Paszkiewicz, S. Wolski, A. Jezowski

We report on lattice specific heat of bulk hexagonal GaN measured by the heat flow method in the temperature range 20-300 K and by the adiabatic method in the range 5-70 K. We fit the experimental data using two temperatures model. The best fit with the accuracy of 3 % was obtained for the temperature independent Debye&#39;s temperature $θ_{\rm D}=365$ {\rm

E. Heinsalu, M. Patriarca, I. Goychuk, P. Hanggi

Fractional, anomalous diffusion in space-periodic potentials is investigated. The analytical solution for the effective, fractional diffusion coefficient in an arbitrary periodic potential is obtained in closed form in terms of two quadratures. This theoretical result is corroborated by numerical simulations for different shapes of the periodic potential. No

Jussi Kalkkinen

Fermion fields on an M-theory five-brane carry a representation of the double cover of the structure group of the normal bundle. It is shown that, on an arbitrary oriented Lorentzian six-manifold, there is always an Sp(2) twist that allows such spinors to be defined globally. The vanishing of the arising potential obstructions does not depend on spin structu

Kim A. Froyshov

We prove a gluing formula for Seiberg--Witten invariants which describes in particular the behaviour of the invariant under blow-up and rational blow-down.

Sungsam Kang, Seokchan Yoon, Youngwoon Choi, Jai-Hyung Lee

We have analyzed the statistical distribution of the fluorescence signal levels in a magneto-optical trap containing a few atoms and observed that it strongly depends on the relative size of the bin time with respect to the trap decay time. We derived analytic expressions for the signal distributions in two limiting cases, long and short bin time limits, and

Bruno P. Zimmermann

The group SL(n,Z) admits a smooth faithful action on the (n-1)-sphere S^(n-1), induced from its linear action on euclidean space R^n. We show that, if m < n-1 and n > 2, any smooth action of SL(n,Z) on a mod 2 homology m-sphere, and in particular on the m-sphere S^m, is trivial.

Klaus Hornberger

We assess the effect of the heat radiation emitted by mesoscopic particles on their ability to show interference in a double slit arrangement. The analysis is based on a stationary, phase-space based description of matter wave interference in the presence of momentum-exchange mediated decoherence.

Y. I. Izotov, P. Papaderos, N. G. Guseva, K. J. Fricke

We present spectroscopic observations with the 3.6m ESO telescope of two emission-line galaxies, J2104-0035 and J0113+0052, selected from the Data Release 4 (DR4) of the Sloan Digital Sky Survey (SDSS). From our data we determine the oxygen abundance of these systems to be respectively 12+logO/H = 7.26+/-0.03 and 7.17+/-0.09, making them the two most metal-d

Yu. A. Shchekinov, E. O. Vasiliev

The influence of ultra-high energy cosmic rays (UHECRs) and decaying dark matter particles on the emission and absorption characteristics of neutral hydrogen in 21 cm at redshifts $z = 10-50$ is considered. In presence of UHECRs 21 cm can be seen in absorption with the brightness temperature $T_b=-(5-10)$ mK in the range $z=10-30$. Decayng particles can stim

Aleksander V. Sidorov, Dimiter B. Stamenov

The target mass effects in polarized DIS have been studied. It was demonstrated that taking into account the first order target mass corrections to g1 a very good approximation of the exact formula is achieved. It was also shown that their magnitude in the preasymptotic DIS region is small except for x > 0.65, where their large effect is partially suppressed

Caijun Zhou

In this paper, we study the properties of noetherian rings with uniform annihilators. It turns out that all these rings should be universally catenary and locally equidimensional. We will give a necessary and sufficient condition for these rings, which enable us to prove that if a ring R is the image of a Cohen-Macaulay ring of finite dimension, then R has a

Dongho Chae

In this paper we rule out the possibility of asymptotically self-similar singularities for both of the 3D Euler and the 3D Navier-Stokes equations. The notion means that the local in time classical solutions of the equations develop self-similar profiles as $t$ goes to the possible time of singularity $T$. For the Euler equations we consider the case where t

Yan-Chuan Cai, Jun Pan

We explore features of redshift distortion in Fourier analysis of N-body simulations. The phases of the Fourier modes of the dark matter density fluctuation are generally shifted by the peculiar motion along the line of sight, the induced phase shift is stochastic and has probability distribution function (PDF) symmetric to the peak at zero shift while the e

S. V. Manakov, P. M. Santini

We construct the formal solution of the Cauchy problem for the dispersionless Kadomtsev - Petviashvili equation as application of the Inverse Scattering Transform for the vector field corresponding to a Newtonian particle in a time-dependent potential. This is in full analogy with the Cauchy problem for the Kadomtsev - Petviashvili equation, associated with

Mikhail S. Plyushchay

In 1932 Ettore Majorana proposed an infinite-component relativistic wave equation for particles of arbitrary integer and half-integer spin. In the late 80s and early 90s it was found that the higher-derivative geometric particle models underlie the Majorana equation, and that its (2+1)-dimensional analogue provides with a natural basis for the description of

Jun Pan

Multifractal measures are applied to three IRAS galaxy subsamples selected by colour from the PSCz catalogue. As shown by generalised dimension spectrum, hot IRAS galaxies are found less clustered than cold galaxies, but the difference is very weak. An alternative tool, the conditional multifractal dimension spectrum reveals apparent peculiarity of the distr

B. Dubetsky, M. A. Kasevich

In the presence of Earth gravity and gravity-gradient forces, centrifugal and Coriolis forces caused by the Earth rotation, the phase of the time-domain atom interferometers is calculated with accuracy up to the terms proportional to the fourth degree of the time separation between pulses. We considered double-loop atom interferometers and found appropriate

Tao Zhou, Jian-Guo Liu, Wen-Jie Bai, Guanrong Chen

In this article, we proposed a susceptible-infected model with identical infectivity, in which, at every time step, each node can only contact a constant number of neighbors. We implemented this model on scale-free networks, and found that the infected population grows in an exponential form with the time scale proportional to the spreading rate. Further mor

Jordan Ellenberg, Akshay Venkatesh

We prove the local-global principle holds for the problem of representations of quadratic forms by quadratic forms, in codimension $\geq 7$. The proof uses the ergodic theory of $p$-adic groups, together with a fairly general observation on the structure of orbits of an arithmetic group acting on integral points of a variety.

R. N. Mohan, Moon Ho Lee, Subash Pokreal

An arrangement of s elements in s rows and s columns, such that no element repeats more than once in each row and each column is called a Latin square of order s. If two Latin squares of the same order superimposed one on the other and in the resultant array if each ordered pair occurs once and only once then they are called othogonal Latin Squares. A freque

N. Seymour, D. Stern, C. De Breuck

We present the results of a comprehensive Spitzer survey of 70 radio galaxies across 1<z<5.2. Using IRAC, IRS and MIPS imaging we determine the rest-frame AGN contribution to the stellar emission peak at 1.6um. The stellar luminosities are found to be consistent with that of a giant elliptical with a stellar mass of 10^11-12Msun. The mean stellar mass remain

Hisakazu Minakata

In trying to answer the question in the title of my talk, I have argued on ground of naturalness that leptonic CP violation is very likely to exist both in the form of the Kobayashi-Maskawa type and the Majorana type phases. The latter part of the argument has to be backed up by a general argument by Yanagida which states that neutrinos must be Majorana part

Tomohiro Harada, Hideki Maeda, B. J. Carr

We consider the possible existence of self-similar solutions containing black holes in a Friedmann background with a stiff fluid or a scalar field. We carefully study the relationship between the self-similar equations in these two cases and emphasize the crucial role of the similarity horizon. We show that there is no self-similar black hole solution surrou

Michael Kapovich

We consider Gromov-Thurston examples of negatively curved n-manifolds which do not admit metrics of constant sectional curvature. We show that for each n some of the Gromov-Thurston manifolds admit strictly convex real-projective structures.

Tatsuo Kobayashi, Haruhiko Terao, Akito Tsuchiya

It is shown that fine-tuning of the Higgs parameters stronger than a few % is required at the best in the models with gauge mediated supersymmetry breaking. With the aim of solving this problem, we consider a new type of models in which the top Yukawa coupling is induced at TeV scale through mass mixing with unknown matter fields. Then it is found that the f

Feng-Lin Wang, Xiao-Lin Chen, Da-Hai Lu, Shi-Lin Zhu

We study the decay widths of the narrow resonances $D_{sj}^*(2317)$ and $D_{sj}(2460)$ in the chiral quark model, together with the well-known $D^\ast$ and $D_s^*$ mesons. All the parameters in our calculation are taken from Godfrey and Isgur&#39;s quark model except the $π^0-η$ mixing angle which is fixed by the $D_s^*$ decay widths. The calculated electrom

S. Gotzinger, L. de S. Menezes, A. Mazzei, O. Benson

We realize controlled cavity-mediated photon transfer between two single nanoparticles over a distance of several tens of micrometers. First, we show how a single nanoscopic emitter attached to a near-field probe can be coupled to high-Q whispering-gallery modes of a silica microsphere at will. Then we demonstrate transfer of energy between this and a second

John Conway, Simon Kochen

On the basis of three physical axioms, we prove that if the choice of a particular type of spin 1 experiment is not a function of the information accessible to the experimenters, then its outcome is equally not a function of the information accessible to the particles. We show that this result is robust, and deduce that neither hidden variable theories nor m

Sameer M. Ikhdair, Ramazan Sever

An alternative approximation scheme has been used in solving the Schrodinger equation to the more general case of exponential screened Coulomb potential, V(r)=-(a/r)\[1+(1+br)e^{-2br}]. The bound state energies of the 1s, $2s, and 3s-states, together with the ground state wave function are obtained analytically upto the second perturbation term.

Daniela Dragoman

The evolution equations of quantum observables are derived from the classical Hamiltonian equations of motion with the only additional assumption that the phase space is non-commutative. The demonstration of the quantum evolution laws is quite general; it does not rely on any assumption on the operator nature of x and p and is independent of the quantum mech

Sameer M. Ikhdair, Ramazan Sever

An alternative approximation scheme has been used in solving the Schrodinger equation for the exponential-cosine-screened Coulomb potential. The bound state energıes for various eigenstates and the corresponding wave functions are obtained analytically up to the second perturbation term.

Gilles Brassard

Quantum cryptography is the only approach to privacy ever proposed that allows two parties (who do not share a long secret key ahead of time) to communicate with provably perfect secrecy under the nose of an eavesdropper endowed with unlimited computational power and whose technology is limited by nothing but the fundamental laws of nature. This essay provid

Ping Han, Rui-Xue Xu, Baiqing Li, Jian Xu

A nonperturbative electron transfer rate theory is developed based on the reduced density matrix dynamics, which can be evaluated readily for the Debye solvent model without further approximation. Not only does it recover for reaction rates the celebrated Marcus&#39; inversion and Kramers&#39; turnover behaviors, the present theory also predicts for reaction

Motomichi Tashiro, Keiji Morokuma, Jonathan Tennyson

Low-energy electron collisions with O$_2$ molecules are studied using the fixed-bond R-matrix method. In addition to the O$_2$ ${X}^3Σ_{g}^-$ ground state, integrated cross sections are calculated for elecron collisions with the ${a}^1Δ_{g}$ and ${b}^1Σ_{g}^+$ excited states of O$_2$ molecules. 13 target electronic states of O$_2$ are included in the model w

Jason A. C. Gallas

It is argued that Wheeler&#39;s insightful idea of delayed choice experiments may be explored at a classical level, arising naturally from number-theoretical conjugacies always necessarily present in the equations of motion. For simple and representative systems, we illustrate how to cast the equations of motion in a form encoding all classical states simult

E. A. Matute

The discussion of our recent work concerning the vector solution of boundary-value problems in electromagnetism is extended to the case of no azimuthal symmetry by means of the spin-weighted spherical harmonics.

R. V. R. Pandya

Under panicky situation, human have tendency to rush toward a particular direction for escape. I show here that this tendency alone causes increase in crowding and which could eventually trigger jamming that is not preferable. Further, it is proposed that potential flow theory can be employed in finding suitable strategy for escape.

R. A. Dias, M. Rapini, P. Z. Coura, B. V. Costa

In this work we present a molecular dynamics simulation of a FFM experiment. The tip-sample interaction is studied by varying the normal force in the tip and the temperature of the surface. The friction force, cA, at zero load and the friction coefficient, $μ$, were obtained. Our results strongly support the idea that the effective contact area, A, decreases

R. A. Dias, M. Rapini, P. Z. Coura, B. V. Costa

We use Monte Carlo and molecular dynamics simulation to study a magnetic tip-sample interaction. Our interest is to understand the mechanism of heat dissipation when the forces involved in the system are magnetic in essence. We consider a magnetic crystalline substrate composed of several layers interacting magnetically with a tip. The set is put thermally i

O. V. Belai, E. V. Podivilov, D. A. Shapiro

An analytic solution for Bragg grating with linear chirp in the form of confluent hypergeometric functions is analyzed in the asymptotic limit of long grating. Simple formulas for reflection coefficient and group delay are derived. The simplification makes it possible to analyze irregularities of the curves and suggest the ways of their suppression. It is sh

Frank Stienkemeier, Kevin K Lehmann

This article provides a review of recent work in the field of helium nanodroplet spectroscopy with emphasis on the dynamical aspects of the interactions between molecules in helium as well as their interaction with this unique quantum solvent. Emphasis is placed on experimental methods and studies introducing recent new approaches, in particular including ti

Seokchan Yoon, Youngwoon Choi, Sangbum Park, Jaisoon Kim

A few 85Rb atoms were trapped in a micron-size magneto-optical trap with a high quadrupole magnetic-field gradient and the number of atoms was precisely controlled by suppressing stochastic loading and loss events via real-time feedback on the magnetic field gradient. The measured occupation probability of single atom was as high as 99%. Atoms up to five wer

V. G. Baryshevsky, V. V. Tikhomirov

The interaction of high energy particles with atomic axes and planes allows to observe in crystal various effects predicted by the quantum electrodynamics of phenomena in strong electromagnetic field. In particular, the effect of electron-positron pair production by gamma-quanta in a semi-uniform field was observed for the first time in eightieth in CERN in

Yu. A. Kalinin, A. E. Hramov

The effect of the electron transverse and longitudinal velocity spread at the entrance to the interaction space on wide-band chaotic oscillations in intense multiple-velocity beams is studied theoretically and numerically under the conditions of formation of a virtual cathode. It is found that an increase in the electron velocity spread causes chaotization o

Anthonie W. J. Muller

In a pioneering study experimental evidence was sought of thermosynthesis, a theoretical biological mechanism for free energy gain from thermal cycling that has been invoked as energy source for the origin of life. A PCR machine applied thermal cycling to the K12 strain of Escherichia coli. The viability of this organism during starvation was determined at c

H. Olivares Pilón

Using the variational method, a detailed study of the lowest m = 0,-1 electronic states of the exotic molecular ion H_4^{3+} in a strong magnetic field, in the linear symmetric configuration parallel to the direction of the magnetic field is carried out. A extended study of the 1σ_g ground state (J.C. López and A. Turbiner, Phys. Rev. A 62, 022510, 2000) was

S. J. H. Petra, P. Sjolund, A. Kastberg

We present a method to obtain power-balanced laser beams for doing quantum-state manipulation experiments with phase-stable double optical lattices. Double optical lattices are constructed using four pairs of overlapped laser beams with different frequency. Our optical scheme provides a phase stability between the optical lattices of 5 mrad/s and laser beams

Mark G. Kuzyk

Using sum rules and a new dipole-free sum-over-states expression, we calculate the fundamental limits of the dispersion of the real and imaginary parts of all electronic nonlinear-optical susceptibilities. As such, these general results can be used to study any nonlinear optical phenomena at any wavelength, making it possible to push both applications and ou

Claudia Ratti, Michael A. Thaler, Wolfram Weise

QCD-based thermodynamics at zero and finite quark chemical potential is studied using an extended Nambu and Jona-Lasinio approach in which quarks couple simultaneously to the chiral condensate and to a background temporal gauge field representing Polyakov loop dynamics. This so-called PNJL model thus includes features of both deconfinement and chiral symmetr

O. Moreno, P. Sarriguren, R. Alvarez-Rodriguez, E. Moya de Guerra

The effect of nuclear deformation on the energy distributions of the Gamow-Teller strength is studied in neutron-deficient Hg, Pb, and Po even isotopes. The theoretical framework is based on a self-consistent deformed Skyrme Hartree-Fock mean field with pairing correlations between like nucleons in BCS approximation and residual spin-isospin interactions tre

C. Providencia, J. da Providencia, Y. Tsue, M. Yamamura

Following the idea, recently, proposed by the present authors for the two-level pairing model, the Lipkin model is reexamined. It is a natural generalization of the method already developed by the present authors with Kuriyama. This model is a schematic model for many-fermion system and obeys the su(2)-algebra. It is shown that the use of the Schwinger boson

Arnold Larson, Gerald A. Miller, M. Strikman

We use a semi-classical approximation to investigate the effects of color transparency on pion electroproduction reactions. The resulting reduced nuclear interactions produce significant, but not dominating, differences with the results of conventional distorted-wave, Glauber-type treatments at kinematics accessible to Jefferson Laboratory. Nuclear effects t

Gregory Berkolaiko

The form factor of a quantum graph is a function measuring correlations within the spectrum of the graph. It can be expressed as a double sum over the periodic orbits on the graph. We propose a scheme which allows one to evaluate the periodic orbit sum for a special family of graphs and thus to recover the expression for the form factor predicted by the Rand

S. V. Manakov, P. M. Santini

We solve the inverse scattering problem for multidimensional vector fields and we use this result to construct the formal solution of the Cauchy problem for the second heavenly equation of Plebanski, a scalar nonlinear partial differential equation in four dimensions relevant in General Relativity, which arises from the commutation of multidimensional Hamilt

S. De Bievre, M. Merkli

We give a complete and rigorous proof of the Unruh effect, in the following form. We show that the state of a two-level system, uniformly accelerated with proper acceleration $a$, and coupled to a scalar bose field initially in the Minkowski vacuum state will converge, asymptotically in the detector&#39;s proper time, to the Gibbs state at inverse temperatur

Pete L. Clark

We study the question of whether algebraic curves of a given genus g defined over a field K must have points rational over the maximal abelian extension K^{ab} of K. We give: (i) an explicit family of diagonal plane cubic curves with Q^{ab}-points, (ii) for every number field K, a genus one curve C_{/Q} with no K^{ab}-points, and (iii) for every g \geq 4 an

Gady Kozma, Zvi Lotker, Gideon Stupp

For a measure mu supported on a compact connected subset of a Euclidean space which satisfies a uniform d-dimensional decay of the volume of balls we show that the maximal edge in the minimum spanning tree of n indepndent samples from mu is, with high probability (log n/n)^(1/d).

Qinian Jin, Aobing Li, YanYan Li

This paper concerns a fully nonlinear version of the Yamabe problem on manifolds with boundary. We establish some existence results and estimates of solutions.

Christian Rosendal

We show that any homomorphism from the homeomorphism group of a compact 2-manifold, with the compact-open topology, or equivalently, with the topology of uniform convergence, into a separable topological group is automatically continuous.

Joel Hass, J. Hyam Rubinstein, Abigail Thompson

We investigate several integer invariants of curves in 3-space. We demonstrate relationships of these invariants to crossing number and to total curvature.

Ioan Bejenaru

We study the local well-posedness theory for the Schrödinger Maps equation. We work in $n+1$ dimensions, for $n \geq 2$, and prove a local well-posedness for small initial data in $H^{\frac{n}{2}+\e}$.

Laurent Fargues

One of the goals of this article is to describe the isomorphism between Lubin-Tate and Drinfeld towers at the level of their skeletons after taking quotient by $\GL_n (Ø_F)\times Ø_D^\times$ or $I\timesØ_D^\times$ where $Ø_D$ is the maximal order in the division algebra with invariant $\frac{1}{n}$ over $F$ and $I$ a Iwahori subgroup of $\GL_n$. We give appl

Miodrag-Cristian Iovanov

We investigate left and right co-Frobenius coalgebras and give equivalent characterizations which prove statements dual to the characterizations of Frobenius algebras. We prove that a coalgebra is left and right co-Frobenius if and only if C is isomorphic to Rat(C*) as right C*-modules and also that this is eqhivalent to the fact that the functors Hom_K(-,K)

Eric Ricard, Christian Rosendal

We consider the unitary group $\U$ of complex, separable, infinite-dimensional Hilbert space as a discrete group. It is proved that, whenever $\U$ acts by isometries on a metric space, every orbit is bounded. Equivalently, $\U$ is not the union of a countable chain of proper subgroups, and whenever $\E\subseteq \U$ generates $\U$, it does so by words of a fi

N. M. Kovalevskaya

A general Riccati equation is integrated in quadratures in case one of its coefficients is an arbitrary function and two others are expressed through it.

Leovigildo Alonso, Ana Jeremias, Marta Perez

This a first step to develop a theory of smooth, etale and unramified morphisms between noetherian formal schemes. Our main tool is the complete module of differentials, that is a coherent sheaf whenever the map of formal schemes is of pseudo finite type. Among our results we show that these infinitesimal properties of a map of usual schemes carry over into

Alexander Schrijver

Let $V=\oC^n$ and let $T:=T(V)\otimes T(V^*)$ be the mixed tensor algebra over $V$. We characterize those subsets $A$ of $T$ for which there is a subgroup $G$ of the unitary group $\UU(n)$ such that $A=T^G$. They are precisely the nondegenerate contraction-closed graded $*$-subalgebras of $T$. While the proof makes use of the First Fundamental Theorem for $\

Ondřej F. K. Kalenda

We investigate Baire-one functions whose graph is contained in a graph of usco mapping. We prove in particular that such a function defined on a metric space with values in $\mathbb{R}^d$ is the pointwise limit of a sequence of continuous functions with graphs contained in the graph of a common usco map.

Thomas Hasanis, Theodoros Vlachos

In this paper we deal with the following problem: Find all Riemannian metrics on a manifold that can be realized isometrically as immersed hypersurfaces in the Euclidean space. We study this problem for a wide class of metrics on hypersurfaces arising from Codazzi tensors.

Fedor Duzhin

Given a domain or, more generally, a Riemannian manifold with boundary, a billiard is the motion of a particle when the field of force is absent. Trajectories of such a motion are geodesics inside the domain; and the particle reflects from the boundary making the angle of incidence equal the angle of reflection. The billiard motion can happen to be a closed

Philippe Rigollet

We consider semi-supervised classification when part of the available data is unlabeled. These unlabeled data can be useful for the classification problem when we make an assumption relating the behavior of the regression function to that of the marginal distribution. Seeger (2000) proposed the well-known &#34;cluster assumption&#34; as a reasonable one. We

Jian Deng, Thomas Y. Hou, Ruo Li, Xinwei Yu

In this article we apply the technique proposed in Deng-Hou-Yu (Comm. PDE, 2005) to study the level set dynamics of the 2D quasi-geostrophic equation. Under certain assumptions on the local geometric regularity of the level sets of $θ$, we obtain global regularity results with improved growth estimate on $| \nabla^{\bot} θ|$. We further perform numerical sim

Don Hadwin, Junhao Shen

In this paper we introduce the concept of the upper free orbit-dimension of a finite von Neumann algebra, and we derive some of its basic properties. Using this concept, we are able to improve most of the applications of free entropy to finite von Neumann algebras, including those with Cartan subalgebras or simple masas, nonprime factors, those with property

Gady Kozma

Let G be a planar graph with polynomial growth and isoperimetric dimension bigger than 1. Then the critical p for Bernoulli percolation on G satisfies p<1.

Ichiro Shimada

We classify all the possible configurations of singular fibers and the torsion parts of Mordell-Weil groups of complex elliptic K3 surfaces. The complete list of 3279 configurations is attached.

Mikhail G. Katz, Stephane Sabourau

We prove an optimal systolic inequality for CAT(0) metrics on a genus~2 surface. We use a Voronoi cell technique, introduced by C.~Bavard in the hyperbolic context. The equality is saturated by a flat singular metric in the conformal class defined by the smooth completion of the curve y^2=x^5-x. Thus, among all CAT(0) metrics, the one with the best systolic

Jean Thierry-Mieg

In Yang-Mills theory, the charges of the left and right massless Fermions are independent of each other. We propose a new paradigm where we remove this freedom and densify the algebraic structure of Yang-Mills theory by integrating the scalar Higgs field into a new gauge-chiral 1-form which connects Fermions of opposite chiralities. Using the Bianchi identit

Jerzy Lukierski

We shall outline two ways of introducing the modification of Einstein&#39;s relativistic symmetries of special relativity theory - the Poincaré symmetries. The most complete way of introducing the modifications is via the noncocommutative Hopf-algebraic structure describing quantum symmetries. Two types of quantum relativistic symmetries are described, one w

Suguru Dobashi

The holographic principle in the pp-wave limit proposed in our previous works is further confirmed by studying impurity non-preserving processes which contain a fermionic BMN operator with one scalar and one fermion impurities. We show that the previously proposed duality relation between the matrix elements of the three point interaction Hamiltonian in the

V. A. Red&#39;kov, George J. Spix

Two known, alternative to each other, forms of the Maxwell&#39;s electromagnetic equations in a moving uniform media are investigated and discussed. Approach commonly used after Minkowski is based on the two tensors: H^{ab} = (D, H /c) and F^{ab} = (E, cB) which transform independently of each other at Lorentz transitions; relationships between fields change

U. Gran, J. Gutowski, G. Papadopoulos, D. Roest

We classify the geometry of all supersymmetric IIB backgrounds which admit the maximal number of $G$-invariant Killing spinors. For compact stability subgroups $G=G_2, SU(3)$ and SU(2), the spacetime is locally isometric to a product $X_n\times Y_{10-n}$ with $n=3,4,6$, where $X_n$ is a maximally supersymmetric solution of a $n$-dimensional supergravity theo

B. Z. Kopeliovich, I. K. Potashnikova, Ivan Schmidt

This lecture presents a short review of the main features of diffractive processes and QCD inspired models. It includes the following topics: (1) Quantum mechanics of diffraction: general properties; (2) Color dipole description of diffraction; (3) Color transparency; (4) Soft diffraction in hard reactions: DIS, Drell-Yan, Higgs production; (5) Why Pomerons

Kenzo Inoue, Kentaro Kojima, Koichi Yoshioka

The radiative electroweak symmetry breaking, the unification of third-generation Yukawa couplings, and flavor-changing rare decay are investigated in two types of supersymmetric SO(10) scenarios taking into account of the effects of neutrino physics, i.e. the observed large generation mixing and tiny mass scale. The first scenario is minimal, including right

S. Yasui, A. Hosaka

We discuss the stability of strangelets -- quark droplets with strangeness -- in the Nambu--Jona-Lasinio model supplemented by a boundary condition for quark confinement. Effects of dynamical chiral symmetry breaking are considered properly inside quark droplets of arbitrary baryon number. We obtain the energy per baryon number of quark droplets with baryon

Gerald V. Dunne, Christian Schubert

We show how to do semiclassical nonperturbative computations within the worldline approach to quantum field theory using ``worldline instantons&#39;&#39;. These worldline instantons are classical solutions to the Euclidean worldline loop equations of motion, and are closed spacetime loops parametrized by the proper-time. Specifically, we compute the imaginar

The ALEPH Collaboration, S. Schael

Deuteron and anti-deuteron production in Z decays has been observed in the ALEPH experiment at LEP. The production rate of anti-deuterons is measured to be 5.9+-1.8+-0.5 10^-6 per hadronic Z decay in the anti-deuteron momentum range 0.62 to 1.03 GeV/c. The coalescence parameter B_2, which characterizes the likelihood of anti-deuteron production, is measured

H1 Collaboration

The production of tau leptons in ep collisions is investigated using data recorded by the H1 detector at HERA in the period 1994-2000. Tau leptons are identified by detecting their decay products, using leptonic and hadronic decay modes. The cross section for the production of tau lepton pairs is measured for the first time at HERA. Furthermore, a search for

Scott M. Oser

Neutrinos in the Standard Model of particle physics are massless, neutral fermions that seemingly do little more than conserve 4-momentum, angular momentum, lepton number, and lepton flavour in weak interactions. In the last decade conclusive evidence has demonstrated that the Standard Model&#39;s description of neutrinos does not match reality. We now know

Maximiliano Ujevic, Patricio S. Letelier

We study the stability of general relativistic static thick disks, as an application we consider the thick disk generated by applying the ``displace, cut, fill and reflect&#34; method, usually known as the image method, to the Schwarzschild metric in isotropic coordinates. The isotropic Schwarzschild thick disk obtained from this method is the simplest model

K. A. Bronnikov, J. C. Fabris, N. Pinto-Neto, M. E. Rodrigues

We study Einstein gravity coupled to a massless scalar field in a static spherically symmetric space-time in four dimensions. Black hole solutions exist when the kinetic energy of the scalar field is negative, that is, for a phantom field. These ``scalar black holes&#39;&#39; have an infinite horizon area and zero temperature. They are related through a conf

C. Lämmerzahl, O. Preuss, H. Dittus

A collection is made of presently unexplained phenomena within our Solar system and in the universe. These phenomena are (i) the Pioneer anomaly, (ii) the flyby anomaly, (iii) the increase of the Astronomical Unit, (iv) the quadrupole and octupole anomaly, and (v) Dark Energy and (vi) Dark Matter. A new data analysis of the complete set of Pioneer data is an