Universitat de Barcelona
Now showing items 1-20 of 44
Esta memoria recoge algunos de los puntos fundamentales e inéditos que han aparecido al iniciar un estudio sobre los métodos espectrales en Análisis y, en particular, sobre los anillos y estructuras diferenciables. Dicho ...
En una primera part s'estudien els conjunts de mesures que prenen valors en un grup reticualt, per a les quals la T-aditivitat es defineix a partir de l'estructura ordenada. L'estudi realitzat a partir de les propietats ...
El teorema de Kolmogorov-Arnold-Moser no asegura la estabilidad cerca de los toros m-dimensionales que se conservan para hamiltonianos casi integrables con "m" grados de libertad. Puede aparecer una difusión de trayectorias ...
The anisotropic Kepler problem was introduced by Gutzwiller as a classical mechanical system which approximates the following quantum mechanical system: the study of bound states of an electron near a donor impurity of a ...
El problema de 3 cossos i, en particular, el problema restringit de 3 cossos, ha estat i és, com diu Wintner, la pedra de toc per als matemàtics de les successives generacions de Newton fins ara. Cada generació ha emprat ...
Se consideran familias de difeomorfismos con un punto fijo parabólico para el valor cero del parámetro y un punto fijo hiperbólico para valores mayores que cero que tengan en este caso puntos homoclínicos asociados a ...
El primer resultado de interpolación de operadores data del año 1911 y es debido a I. Schur. Dos años más tarde, Young prueba un resultado del mismo tipo referente a espacios Lp y a un operador L La extensión de estos ...
It is known that for the study of continuous dynamical systems the discret case plays an important role because, with it we can study the continuous one by using the Poincaré return map. In the discret case we can distinguish ...
In this work we study several topics concerning quasi-periodic time-dependent perturbations of ordinary differential equations. This kind of equations appear as models in many applied problems of Celestial Mechanics, and ...
L'objectiu del treball és mostrar que alguns aspectes de certs sistemes dinàmics discrets bidimensionals poden ser estudiats mitjançant sistemes de dimensió 1 que corresponen a casos particulars o simplificacions. Els tres ...
La memòria recull contribucions a diversos aspectes del problema de l'estabilitat en sistemes hamiltonians quasi-integrables. Aquests aspectes inclouen resultats d'estabilitat efectiva, que comporten el confinament de ...
We have divided this thesis in four parts:<br/><br/>a) PART I: Exact symplectic geometry (introduction of the problems). This part contains the basic tools of symplectic geometry and outlines the four subjects that we have ...
In general, when beginning to explore any scientific field, one focuses on the generic situations; that is, one centers on the behaviours that appear in “most” of the cases encountered in practice. This methodology ...
This works has been organized in three parts. The first (Chapter 1 to 5) is dedicated to the development and study of a procedure for the accurate computation of frequencies, as well ans the related Fourier coefficients, ...
DE LA TESIS:<br/><br/>El contenido de esta tesis se enmarca dentro del Análisis Real. En particular, trata del estudio de ciertos problemas de la teoría de pesos, (una referencia clásica sobre esta teoría es el libro de ...
El sistema de les marques s'enquadra dins del camp de l'anàlisi intervalar modal. <br/>En aquest context la tesi aporta un estudi de les operacions lineals, de la seva semàntica i sobretot de la seva operativitat quan les ...
In this Thesis we address the study of some non-linear evolution equations (e.g. pde's) modelling the dynamics of sexually-reproducing structured populations, with special emphasis on biological evolution driven by natural ...
In this thesis, we present a proof of the meromorphic non-integrability for some problems arising from Celestial Mechanics, as well as a new necessary condition for partial integrability in a wider Hamiltonian setting. ...
In the early 1970 fs, R. Coifman and G. Weiss, generalizing the techniques introduced by A. Calderon, developed a method for transferring abstract convolution type operators, defined on general topological groups, and their ...
Formation flying offers space-dependent disciplines such as astrophysics, astrodynamics, and geodesy, to name a few, the possibility of creating large spaceborne sensors from an array of small spacecraft flying in formation. ...
