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Um texto de geometria hiperbólica / A text of hyperbolic geometryArcari, Inedio 14 April 2008 (has links)
Orientador: Edson Agustini / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Computação / Made available in DSpace on 2018-08-11T06:10:14Z (GMT). No. of bitstreams: 1
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Previous issue date: 2008 / Resumo: A presente dissertação é um texto introdutório de Geometria Hiperbólica com alguns resultados e comentários de Geometria Elíptica. Nossa intenção foi compilar um material que possa ser utilizado em cursos introdutórios de Geometria Hiperbólica tanto em nível de licenciatura quanto de bacharelado. Para tornar o texto mais acessível, notas históricas sobre a bela página do desenvolvimento das Geometrias Não Euclidianas foram introduzidas logo no primeiro capítulo. Procuramos ilustrar fartamente o texto com figuras dentre as quais várias que foram baseadas no Modelo Euclidiano do Disco de Poincaré para a Geometria Hiperbólica. Atualmente, o estudo de Geometria Hiperbólica tem sido bastante facilitado pelo uso de softwares de geometria dinâmica, como o Cabri-Géometre, GeoGebra e NonEuclid, sendo esses dois últimos softwares livres / Abstract: The present work is an introductory text of Hyperbolic Geometry with some results and comments of Elliptic eometry. Our aim in this work were to compile a material that can be used as introduction to Hyperbolic Geometry inundergraduated courses. In the first chapter we introduced historical notes about the beautiful development of the Non Euclid Geometries in order to turn the text more interesting and accesible. We illustrated the text with many figures which were done on the Euclidean Model of the Poincaré' s Disk for the Hyperbolic Geometry. In this way, the study of Hyperbolic Geometry has been softened by the use of softwares of dynamic geometry, like Cabri-Geométre and the freeware softwares GeoGebra and NonEuclid / Mestrado / Mestre em Matemática
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Étude topologique du flot horocyclique : le cas des surfaces géométriquement infinies / Topological study of the horocycle flow : the case of geometrically infinite surfacesBellis, Alexandre 22 May 2018 (has links)
On étudie le comportement topologique du flot horocyclique sur des surfaces hyperboliques géométriquement infinies. Cette étude est intimement liée à celle du flot géodésique sur ces surfaces. Le premier chapitre commence par introduire les objets de géométrie hyperbolique que nous utiliserons. Il présente ensuite une classe de surfaces, les flûtes hyperboliques, qui couvrent une grande partie de la complexité des surfaces géométriquement infinies. Enfin, il aborde la notion de finesse asymptotique d'une demi-géodésique, qui donne la limite inférieure du rayon d'injectivité de la surface le long de la demi-géodésique. Le deuxième chapitre est consacré aux propriétés classiques du flot horocyclique sur lesquelles nous baserons nos preuves. Le troisième chapitre concerne l'étude de l'intersection entre l'adhérence de l'orbite horocyclique issue d'un vecteur u d'une surface hyperbolique et la demi orbite géodésique issue de ce même vecteur. Nous montrons que si la finesse asymptotique de la demi-orbite géodésique issue de u est finie et si u n'est pas périodique pour le flot horocyclique, cette intersection contient une infinité divergente de points. Par ailleurs, si la finesse asymptotique est nulle, alors cette intersection est égale à toute la demi-orbite géodésique positive. Nous montrons cependant que même si la finesse asymptotique n'est pas nulle, la demi-orbite géodésique peut tout de même être contenue dans cette intersection. Le quatrième chapitre étudie les liens entre une orbite horocyclique issue d'un vecteur u et la feuille fortement stable associée. Nous commençons par montrer que les adhérences de ces deux ensembles coïncident toujours. Cependant, cette propriété ne s'étend pas aux ensembles eux-mêmes et nous donnons ensuite une condition suffisante pour que qu'ils ne coïncident pas. Nous montrons qu'alors la feuille fortement stable est une union d'une quantité non dénombrable d'orbites horocycliques. / We study the topological behavior of the horocycle flow on geometrically infinite hyperbolic surfaces. This study and that of the geodesic flow are deeply interwoven. The first chapter introduces the basic objects of hyperbolic geometry that we will use. Next, it presents a class of surfaces, the hyperbolic flutes, which carries most of the complexity of geometrically infinite surfaces. Then, it details the notion of asymptotic thinness for a half-geodesic, which determines the size of the most thin parts that this half-geodesic crosses. The second chapter focuses on the classical properties of the horocycle flow on which we will base our proofs. The third chapter presents the study of the intersection between the closure of a horocyclic orbit stemming from a vector u on a hyperbolic surface and the positive half-geodesic stemming from the same vector. We show that if the asymptotic thinness of the half-orbit stemming from u is finite and if u is not periodic for the horocycle flow, then this intersection contains an unbounded sequence of points. Moreover, if the asymptotic thinness is zero, then all the halfgeodesic orbit is included in the intersection. However, we also prove that the half-geodesic orbit can be included in the intersection and even if the asymptotic thinness is not zero. The fourth chapter studies the links between a horocyclic orbit starting from a vector u and the strong stable manifold associated to u. We first show that the closure of these two sets are always the same. However, we then give a sufficient condition for these two sets to be different and we prove that in this case, the strong stable manifold is a reunion of an uncountable number of horocyclic orbits.
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