Browse publicly accessible academic documents published in 2005.
3227 documents
We are interested in coupled microscopic/macroscopic models describing the evolution of particles dispersed in a fluid. The system consists in a Vlasov-Fokker-Planck equation to describe the microscopic motion of the particles coupled to the Euler equations for a compressible…
"Vegeu el resum a l'inici del document del fitxer adjunt".
"Vegeu el resum a l'inici del document del fitxer adjunt".
"Vegeu el resum a l'inici del document del fitxer adjunt".
We prove a general Zariski-van Kampen-Lefschetz type theorem for higher homotopy groups of generic and nongeneric pencils on singular open complex spaces.
The filling length of an edge-circuit η in the Cayley 2-complex of a finite presentation of a group is the minimal integer length L such that there is a combinatorial null-homotopy of η down to a base point through loops of length at most L. We introduce similar notions in which…
"Vegeu el resum a l'inici del document del fitxer adjunt".
We quantify the long-time behavior of a system of (partially) inelastic particles in a stochastic thermostat by means of the contractivity of a suitable metric in the set of probability measures. Existence, uniqueness, boundedness of moments and regularity of a steady state are…
DOI: 10.1007/s10955-004-8785-5
"Vegeu el resum a l'inici del document del fitxer adjunt".
Vegeu el resum a l'inici del document del fitxer adjunt
We review several results concerning the long time asymptotics of nonlinear diffusion models based on entropy and mass transport methods. Semidiscretization of these nonlinear diffusion models are proposed and their numerical properties analysed. We demonstrate the long time…
An algebraic decay rate is derived which bounds the time required for velocities to equilibrate in a spatially homogeneous flowthrough model representing the continuum limit of a gas of particles interacting through slightly inelastic collisions. This rate is obtained by…
We prove that the fundamental group of any Seifert 3-manifold is conjugacy separable. That is, conjugates may be distinguished infinite quotients or, equivalently, conjugacy classes are closed in the pro-finite topology.
We discuss metric and combinatorial properties of Thompson's group T, such as the normal forms for elements and uniqueness of tree pair diagrams. We relate these properties to those of Thompson's group F when possible, and highlight combinatorial differences between the two…
We describe fractal tessellations of the complex plane that arise naturally from Cannon-Thurston maps associated to complete, hyperbolic, once-punctured-torus bundles. We determine the symmetry groups of these tessellations.
Vegeu el resum a l'inici del document del fitxer adjunt.
Here we describe the results of some computational explorations in Thompson's group F. We describe experiments to estimate the cogrowth of F with respect to its standard finite generating set, designed to address the subtle and difficult question whether or not Thompson's group…
Vegeu el resum a l'inici del document del fitxer adjunt.
Rotation distance quantifies the difference in shape between two rooted binary trees of the same size by counting the minimum number of elementary changes needed to transform one tree to the other. We describe several types of rotation distance, and provide upper bounds on…
Vegeu el resum a l'inici del document del fitxer adjunt.
Vegeu el resum a l'inici del document del fitxer adjunt
Vegeu el resum a l'inici del document del fitxer adjunt
Given a non-positively curved 2-complex with a circle-valued Morse function satisfying some extra combinatorial conditions, we describe how to locally isometrically embed this in a larger non- positively curved 2-complex with free-by-cyclic fundamental group. This embedding…
Vegeu el resum a l'inici del document del fitxer adjunt
We say the endomorphism problem is solvable for an element W in a free group F if it can be decided effectively whether, given U in F, there is an endomorphism Φ of F sending W to U. This work analyzes an approach due to C. Edmunds and improved by C. Sims. Here we prove that the…
We describe an equivalence of categories between the category of mixed Hodge structures and a category of vector bundles on the toric complex projective plane which verify some semistability condition. We then apply this correspondence to define an invariant which generalises…
We consider linear stochastic differential-algebraic equations with constant coefficients and additive white noise. Due to the nature of this class of equations, the solution must be defined as a generalised process (in the sense of Dawson and Fernique). We provide sufficient…
We prove that any subanalytic locally Lipschitz function has the Sard property. Such functions are typically nonsmooth and their lack of regularity necessitates the choice of some generalized notion of gradient and of critical point. In our framework these notions are defined in…
Vegeu el resum a l'inici del document del fitxer adjunt
We provide some guidelines for deriving new projective hash families of cryptographic interest. Our main building blocks are so called group action systems; we explore what properties of this mathematical primitives may lead to the construction of cryptographically useful…
Vegeu el resum a l'inici del document del fitxer adjunt
Using the continuation method we prove that the circular and the elliptic symmetric periodic orbits of the planar rotating Kepler problem can be continued into periodic orbits of the planar collision restricted 3-body problem. Additionally, we also continue to this restricted…
Let F be a free group of rank at least three. We show that some retracts of F previously studied by Martino-Ventura are not equal to the fixed subgroup of any group of automorphisms of F. This shows that, in F, there exist subgroups that are equal to the fixed subgroup of some…
The paper contributes to the investigation of zero-dimensional rings which can be written as a directed union of Artinian subrings. We give conditions on DU(R) in order to be nonempty.
Jorgenson, Jay; Kramer, Jürg
Friedman, Sy D.
In this paper we obtain the necessary and sufficient conditions for embedding results of different function classes. The main result is a criterion for embedding theorems for the so-called generalized Weyl-Nikol'skii class and the generalized Lipschitz class. To define the…
Vegeu el resum a l'inici del document del fitxer adjunt
It is known that, in a locally presentable category, localization exists with respect to every set of morphisms, while the statement that localization with respect to every (possibly proper) class of morphisms exists in locally presentable categories is equivalent to a…
Some existence results are obtained for periodic solutions of nonautonomous second-order differential inclusions systems with p-Laplacian
Entre las décadas de 1930 y 1950 Misael Acosta Solís, miembro de la elite económica serrana y destacado geobotánico y forestal, lideró un proceso de institucionalización del conservacionismo en el Ecuador. Instituciones privadas y gubernamentales de corte conservacionista…
Hem estudiat la influència de la política científica francesa a Espanya entre 1946 i 1964, la seva repercussió a Barcelona i la creació de diverses institucions patrocinades pel govern francès. Hem analitzat els cursos de mecànica quàntica dels anys seixanta que va impartir…
EconStor is a publication server for scholarly economic literature, provided as a non-commercial public service by the ZBW.
EconStor is a publication server for scholarly economic literature, provided as a non-commercial public service by the ZBW.
L’objectiu principal d’aquest treball és l’implementació d’un sistema de control basat en la Teoria de Control Repetitiu que permeti resoldre el problema del rebuig de pertorbacions periòdiques de freqüència constant. El projecte comprèn també la determinació del model d’una…
EconStor is a publication server for scholarly economic literature, provided as a non-commercial public service by the ZBW.
