• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 33
  • 20
  • 10
  • 5
  • 2
  • Tagged with
  • 79
  • 30
  • 26
  • 14
  • 11
  • 9
  • 9
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • 7
  • 7
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Métodos algébricos para a obtenção de formas gerais reversíveis-equivariantes / Algebraic methods for the computation of general reversible-equivariant mappings

Iris de Oliveira 10 March 2009 (has links)
Na análise global e local de sistemas dinâmicos assumimos, em geral, que as equações estão numa forma normal. Em presença de simetrias, as equações e o domínio do problema são invariantes pelo grupo formado por estas simetrias; neste caso, o campo de vetores é equivariante pela ação deste grupo. Quando, além das simetrias, temos também ocorrência de anti-simetrias - ou reversibilidades - as equações e o domínio do problema são ainda invariantes pelo grupo formado pelo conjunto de todas as simetrias e anti-simetrias; neste caso, o campo de vetores é reversível-equivariante. Existem muitos modelos físicos onde simetrias e anti-simetrias aparecem naturalmente e cujo efeito pode ser estudado de uma forma sistemática através de teoria de representação de grupos de Lie. O primeiro passo deste processo é colocar a aplicação que modela tal sistema numa forma normal e isto é feito com a dedução a priori da forma geral dos campos de vetores. Esta forma geral depende de dois componentes: da base de Hilbert do anel das funções invariantes e dos geradores do módulo das aplicações reversíveis-equivariantes. Neste projeto, nos concentramos principalmente na aplicação de resultados recentes da literatura para a construção de uma lista de formas gerais de aplicações reversíveisequivariantes sob a ação de diferentes grupos. Além disso, adaptamos ferramentas algébricas da literatura existentes no contexto equivariante para o estudo sistemático de acoplamento de células idênticas no contexto reversível-equivariante / In the global and local analysis of dynamical systems, we assume, in general, that the equations are in a normal form. In presence of symmetries, the equations and the problem domain are invariant under the group formed by these symmetries; in that case, the vector field is equivariant by the action of this group. When, in addition to the symmetries, we have the occurrence of anti-symmetries - or reversibility - the equations and the problem domain are still invariant by the group formed by the set of all symmetries and anti-symmetries; in this case, the vector field is reversible-equivariant. There are many physical models where both symmetries and anti-symmetries occur naturally and whose effect can be studied in a systematic way through group representation theory. The first step of this process is to put the mapping that model the system in a normal form, and this is done with the deduction of the general form of the vector field. This general form depends on two components: the Hilbert basis of the invariant function ring and also the generators of the module of the revesible-equivariants. In this work, we mainly focus on the applications of recent results of the literature to build a list of general forms of reversible-equivariant mappings under the action of different groups. We also adapt algebraic tools of the existing literature in the equivariant context to the systematic study of coupling of identical cells in the reversible-equivariant context
62

Ações de p-grupos sobre produto de esferas, co-homologia dos grupos virtualmente cíclicos (\'Z IND.a\' X| \'Z IND. b\' )X| Z e [\'Z IND.a\' X| (\'Z IND.b\' X \'Q IND.2 POT. i\' )] X| Z e cohomologia de Tate / Actions of groups on sphere product, cohomology of virtually cyclic groups (ZaX| Zb)X| Z and [ZaX|(ZbXQ2i)]X|Z and Tate Cohomology

Soares, Marcio de Jesus 09 October 2008 (has links)
Neste trabalho inicialmente estudamos o rank da co-homologia do espaço dos pontos fixos de uma \'Z IND.p\' - ação semilivre sobre espaços X~p \' S POT. n\' x \'S POT.n\' e X~p \'S POT.n\' x \'S POT.n\' x \'S POT.n\' , com n>0. Em seguida, estudamos uma extensão para ações de p-grupos sobre espaços X~p \'S POT.n\' X \'S POT.m\', com 0< n \'< OU =\' m. Como parte do material utilizado demos uma descrição do diferencial d1 de uma seqüência espectral que converge para co-homologia equivariante de Tate, bem como uma versão da Fórmula de Künneth para a co-homologia equivariante de Tate. Na parte final, motivado pelo problemas de descrição de espaços de órbita de ações de grupos infinito, calculamos as co-homologias dos grupos virtualmente cíclicos (\'Z IND.a\' X| \' Z IND. b\' )X| Z e [\'Z POT.a\' X|(\'Z IND.b\' X \'Q IND. 2 POT.i\') ]X| Z / In this work is studied the rank of the fixed point set of a semifree action on spaces X~p \'S POT.n\' X \'S POT.n\' and X~p \'S POT.n\' X \'S POT.n\' X \'S POT.n\' , with n>0. We also consider the extension of the result for actions of p-groups on spaces X~p \'SPOT.n\' X \' S POT.m\' , with 0<n \'< OR =\' m. As result of the techniques used, we give a description of the differential d1 of a spectral sequence that converges to Tate equivariant cohomology, as well a version of the Künneth Formule to Tate equivariant cohomology. At the end, motivated by the space form problem for infinite groups we compute the cohomology of the virtually cyclic groups (\'Z IND. a\' X| \'Z IND. b\' )X| Z and [\'Z IND.a\' X|(\'Z IND. b\' X \'Q IND2 POT. i\' )] X| Z
63

Teoria de forma normal para campos vetoriais reversíveis equivariantes / Normal form theory for reversible eqauivariant vector fields

Zeli, Iris de Oliveira 25 April 2013 (has links)
Neste trabalho, apresentamos um método algébrico para obter formas normais de campos vetoriais reversíveis equivariantes. Adaptamos o método clássico de Belitskii-Elphick, usando ferramentas da teoria invariante para estabelecer fórmulas que consideram as simetrias e antissimetrias como ponto de partida. Mostramos que este método, mesmo sem simetrias, possui uma estreita relação com o método da transversal completa da teoria de singularidades. Com as ferramentas desenvolvidas nesta tese, a forma normal obtida e uma série formal que não depende do cálculo do kernel do chamado operador homológico. Formas normais para duas classes de campos, ressonantes e não ressonantes, são apresentadas, para diferentes representações do grupo \'Z IND. 2\' x \'Z IND. 2\' cuja linearização tem uma parte nilpotente de dimensão 2 e uma parte semi-simples com autovalores puramente imaginários / We give an algebraic method to obtain normal forms of reversible equivariant vector fields. We adapt the classical method by Belitskii-Elphick using tools from invariant theory to establish formulae that take symmetries into account as a starting point. We show that this method, even without symmetries, has a close relation to complete transversal of singularities theory. Applying the method developed in this thesis, the resulting normal form is a formal series which does not depend of the computation of the kernel of the so called homologic operator. Normal forms of two classes of non-resonant and resonant cases are presented, for dierent representations of the group \'Z INT. 2\' x \'Z INT. 2\' - with linearization having a 2 - dimensional nilpotent part and a semisimple part with purely imaginary eigenvalues
64

Simmetries in binary differential equations / Simetrias em equações diferenciais binárias

Tempesta, Patricia 28 April 2017 (has links)
The purpose of this thesis in to introduce the systematic study of symmetries in binary differential equations (BDEs). We formalize the concept of a symmetric BDE, under the linear action of a compact Lie group. One of the main results establishes a formula that relates the algebraic and geometric effects of the occurrence of the symmetry in the problem. Using tools from invariant theory and representation theory for compact Lie groups we deduce the general forms of equivariant binary differential equations under compact subgroups of O(2). A study about the behavior of the invariant straight lines on the configuration of homogeneous BDEs of degree n is done with emphasis on cases in which n = 0 and n = 1. Also for the linear case (n = 1) the equivariant normal forms are presented. Symmetries of linear 1-forms are also studied and related with symmetries of tangent orthogonal vectors fields associated with it. / O objetivo desta tese é introduzir o estudo sistemático de simetrias em equações diferenciais binárias (EDBs). Neste trabalho formalizamos o conceito de EDB simétrica sobre a ação de um grupo de Lie compacto. Um dos principais resultados é uma fórmula que relaciona o efeito geométrico e algébrico das simetrias presentes no problema. Utilizando ferramentas da teoria invariante e de representação para grupos compactos deduzimos as formas gerais para EDBs equivariantes. Um estudo sobre o comportamento das retas invariantes na configuração de EDBs com coeficientes homogêneos de grau n é feito com ênfase nos casos de grau 0 e 1, ainda no caso de grau 1 são apresentadas suas formas normais. Simetrias de 1-formas lineares são também estudadas e relacionadas com as simetrias dos seus campos tangente e ortogonal.
65

Théorie de l'indice pour les familles d'opérateurs G-transversalement elliptiques / Index theory for families of G-transversally elliptic operators

Baldare, Alexandre 16 February 2018 (has links)
Le problème de l'indice est de calculer l'indice d'un opérateur elliptique en termes topologiques. Ce problème fut résolu par M. Atiyah et I. Singer en 1963 dans "The index of elliptic operators on compact manifolds". Quelques années plus tard, ces auteurs ont fourni une nouvelle preuve dans "The index of elliptic operators I" permettant plusieurs généralisations et applications. La première est la prise en compte de l'action d'un groupe compact G, dans ce cadre on obtient une égalité dans l'anneau des représentations de G. Par la suite ils ont généralisé ce résultat au cadre des familles d'opérateurs elliptiques paramétrées par un espace compact dans "The index of elliptic operators IV", ici l'égalité vit dans la K-théorie de l'espace paramétrant la famille.Une autre généralisation importante est celle des opérateurs transversalement elliptiques par rapport à l'action d'un groupe G, c'est-à-dire elliptiques dans le sens transverse aux orbites de l'action d'un groupe sur une variété. Cette classe d'opérateurs a été étudié pour la première fois dans le cadre d'un opérateur P agissant sur une variété M par M. Atiyah (et I. Singer) dans "Elliptic operators and compact groups", en 1974. Dans cet article l'auteur définit une classe indice et montre qu'elle ne dépend que de la classe du symbole en K-théorie. Il montre ensuite qu'elle vérifie différents axiomes : action libre, multiplicativité et excision. Ces différents axiomes permettent alors de ramener le calcul de l'indice à un espace euclidien muni de l'action d'un tore. Par la suite, cette classe d'opérateurs a été étudier du point de vue de la K-théorie bivariante par P. Julg [1982] et plus récemment dans le cadre des actions propres sur une variété non compacte par G. Kasparov [2016].Dans cette thèse, nous nous intéressons aux familles d'opérateurs G-transversalement elliptiques. Nous définissons une classe indice en K-théorie bivariante de Kasparov. Nous vérifions qu'elle ne dépend que de la classe du symbole de la famille en K-théorie. Nous montrons que notre classe indice vérifie les propriétés d'action libre, de multiplicativité et d'excision espérées en K-théorie bivariante. Nous montrons ensuite un théorème d'induction et de compatibilité avec les applications de Gysin. Ces derniers théorèmes permettent de ramener le calcul de l'indice au cas d'une famille triviale pour l'action d'un tore comme dans le cadre d'un seul opérateur sur une variété. Nous démontrons ensuite qu'on peut associer à cette classe indice un caractère de Chern à coefficients distributionnels sur G à valeurs dans la cohomologie de de Rham de l'espace paramétrant lorsque c'est une variété. Pour ce faire, nous utilisons l'homologie locale de M. Puschnigg [2003] et une technique de M. Hilsum et G. Skandalis [1987]. Par la suite, nous nous intéressons aux formules de Berline et Vergne dans ce cadre. Avant de passer aux formules générales pour une famille d'opérateurs G-transversalment elliptiques, on commence par regarder si on obtient les mêmes formules dans le cadre elliptique. On montre alors des égalités similaires à celles obtenues par N. Berline et M. Vergne [1985] dans le cadre d'un opérateur elliptique G-invariant. Dans un dernier chapitre, on montre la formule de Berline-Vergne dans le cadre des familles d'opérateurs G-transversalement elliptiques. On utilise ici la formule de Berline-Vergne pour un opérateur G-transversalement elliptique et les différentes techniques mises en place dans les chapitres précédents. / The index problem is to calculate the index of an elliptic operator in topological terms. This problem was solved by M. Atiyah and I. Singer in 1963 in "The index of elliptic operators on compact manifolds". Few years later, these authors have given a new proof in "The index of elliptic operators I" allowing several generalizations and applications. The first is taking into account of the action of a compact group G, in this frame they obtain an equality in the ring of the representations of G. Later they generalized this result to the framework of the families of elliptic operators parameterized by a compact space in "The index of elliptic operators IV", here equality lives in the K-theory of the space of parameter.Another important generalization is the transversely elliptic operators with respect to a group action, that is to say, elliptic in the transverse direction to the orbits of a group action on a manifold. This class of operators has been studied for the first time by M. Atiyah (and I. Singer) in "Elliptic operators and compact groups", in 1974. In this article the author defines an index class and shows that it depends only on the symbol class in K-theory. Then he shows that it verifies different axioms: free action, multiplicativity and excision. These different axioms allows to reduce the calculation of the index to an Euclidean space equipped with an action of a torus. Next, this class of operators has been studied from the point of view of bivariant K-theory by P. Julg [1982] and more recently in the context of proper action on a non-compact manifolds by G. Kasparov [2016].In this thesis, we are interested in families of G-transversely elliptic operators. We define an index class in Kasparov bivariant K-theory. We verify that it depends only on the class of the symbol of the family in K-theory. We show that our index class satisfies the expected free action, multiplicativity and excision properties in bivariant K-theory. We then show a theorem of induction and compatibility with Gysin maps. These last theorems allows to reduce the calculation of the index to the case of a trivial family for the action of a torus as in the framework of a single operator on a manifold. We then prove that we can associate to this index class a Chern character with distributional coefficients on G with values ​​in the de Rham cohomology of the parameter space when it is a manifold. To do this, we use the bivariant local cyclic homology of M. Puschnigg [2003] and a technique of M. Hilsum and G. Skandalis [1987].Before treating the general framework of families of G-transversely elliptic operators, we look at the elliptic case. We show that the expected formulas are true in this context. In the last chapter, we show the Berline-Vergne formula in the context of families of G-transversely elliptic operators. We use here the Berline-Vergne formula for a G-transversely elliptic operator and the different methods used in the previous chapters.
66

Ações de p-grupos sobre produto de esferas, co-homologia dos grupos virtualmente cíclicos (\'Z IND.a\' X| \'Z IND. b\' )X| Z e [\'Z IND.a\' X| (\'Z IND.b\' X \'Q IND.2 POT. i\' )] X| Z e cohomologia de Tate / Actions of groups on sphere product, cohomology of virtually cyclic groups (ZaX| Zb)X| Z and [ZaX|(ZbXQ2i)]X|Z and Tate Cohomology

Marcio de Jesus Soares 09 October 2008 (has links)
Neste trabalho inicialmente estudamos o rank da co-homologia do espaço dos pontos fixos de uma \'Z IND.p\' - ação semilivre sobre espaços X~p \' S POT. n\' x \'S POT.n\' e X~p \'S POT.n\' x \'S POT.n\' x \'S POT.n\' , com n>0. Em seguida, estudamos uma extensão para ações de p-grupos sobre espaços X~p \'S POT.n\' X \'S POT.m\', com 0< n \'< OU =\' m. Como parte do material utilizado demos uma descrição do diferencial d1 de uma seqüência espectral que converge para co-homologia equivariante de Tate, bem como uma versão da Fórmula de Künneth para a co-homologia equivariante de Tate. Na parte final, motivado pelo problemas de descrição de espaços de órbita de ações de grupos infinito, calculamos as co-homologias dos grupos virtualmente cíclicos (\'Z IND.a\' X| \' Z IND. b\' )X| Z e [\'Z POT.a\' X|(\'Z IND.b\' X \'Q IND. 2 POT.i\') ]X| Z / In this work is studied the rank of the fixed point set of a semifree action on spaces X~p \'S POT.n\' X \'S POT.n\' and X~p \'S POT.n\' X \'S POT.n\' X \'S POT.n\' , with n>0. We also consider the extension of the result for actions of p-groups on spaces X~p \'SPOT.n\' X \' S POT.m\' , with 0<n \'< OR =\' m. As result of the techniques used, we give a description of the differential d1 of a spectral sequence that converges to Tate equivariant cohomology, as well a version of the Künneth Formule to Tate equivariant cohomology. At the end, motivated by the space form problem for infinite groups we compute the cohomology of the virtually cyclic groups (\'Z IND. a\' X| \'Z IND. b\' )X| Z and [\'Z IND.a\' X|(\'Z IND. b\' X \'Q IND2 POT. i\' )] X| Z
67

Bifurcações de campos vetoriais em duas zonas com simetria / Bifurcations of vector fields in two zones with symmetry

Castro, Ubirajara José Gama de 28 November 2017 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-12-27T14:12:36Z No. of bitstreams: 2 Tese - Ubirajara José Gama de Castro - 2017.pdf: 14188106 bytes, checksum: 942882692cd259cae5e8d267f6ac1188 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-12-28T09:43:26Z (GMT) No. of bitstreams: 2 Tese - Ubirajara José Gama de Castro - 2017.pdf: 14188106 bytes, checksum: 942882692cd259cae5e8d267f6ac1188 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-12-28T09:43:26Z (GMT). No. of bitstreams: 2 Tese - Ubirajara José Gama de Castro - 2017.pdf: 14188106 bytes, checksum: 942882692cd259cae5e8d267f6ac1188 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-11-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this work we study reversible vector fields in two zones and equivariant vector fields in two zones. Our main result is the classification of the symmetric singularities of codimensions 0,1 and 2 of such vector fields. More precisely, in the reversible case in R3, where the dimension of the fixed points variety of the involution associated to the vector field is 2, we present all bifurcation diagram of the codimensions 1 and 2 singularities, describing the changes in the behavior of the symmetric singularities and tangents of the vector field with the transition manifold, S, according to the variation of the bifucartion parameter. We also show the existence of invariant cylinders and, in this case, doing small perturbations we determine invariant manifolds that persisted and we determine the number of limit cycles that were born. When the vector field defined on two zones is equivariant, the dynamic is enriched with the emergence of the sliding vector field and we also do a local study and the classification of singularities (and pseudo-singularities) of codimensions 0,1 and 2. We show the existence of homoclinic sliding orbit and that it is a codimension one phenomenon. Moreover, provided the symmetry we get a double Shilnikov sliding orbit. / Neste trabalho, estudamos campos vetoriais em duas zonas reversíveis e campos vetoriais em duas zonas equivariantes. Nosso resultado principal é a classificação das singularidades simétricas de codimensões 0, 1 e 2 de tais campos vetoriais. Mais precisamente, no caso reversível em R3, onde a dimensão da variedade de pontos fixos da involução associada ao campo vetorial é 2, apresentamos todos os diagramas de bifurcação das singularidades de codimensão 1 e 2, descrevendo as mudanças no comportamento das singularidades simétricas e das tangências do campo vetorial com a variedade de transição S, de acordo com a variação do parâmetro de bifurcação. Mostramos também a existência de cilindros invariantes e, nesse caso, fazendo pequenas perturbações determinamos variedades invariantes que persistiram e determinamos o número de ciclos limites que surgiram. Quando o campo vetorial definido em duas zonas é equivariante, a dinâmica é enriquecida com o surgimento do campo vetorial deslizante e também fazemos um estudo local e a classificação das singularidades (e pseudossingularidades) de codimensões 0, 1 e 2. Mostramos a existência de órbitas homoclínicas deslizantes e que esse é um fenômeno de codimensão 1 e devido à simetria do campo vetorial equivariante, teremos um duplo Shilnikov deslizante.
68

Grau de aplicações G-equivariantes entre variedades generalizadas / Degree of G-equivariant maps between generalized manifolds

Norbil Leodan Cordova Neyra 09 June 2014 (has links)
Neste trabalho estenderemos os resultados obtidos por Hara [34] e J. Jaworowski [38] substituindo as G-variedades por G-variedades generalizadas sobre Z. Além disso, provamos uma fórmula de comparação geral para grau de aplicações de uma variedade generalizada sobre uma esfera que são equivariantes com respeito a ações de grupos finitos, obtendo uma generalização do resultado de A. Kushkuley e Z. Balanov [40] / In this work, we extend the results obtained by Y. Hara [34] and J. Jaworowski [38] by replacing the free G-manifolds by free generalized G-manifolds over Z. Moreover, we prove a general comparison formula for degrees of equivariant maps from a generalized manifold to a sphere which are equivariant with respect to finite group actions, obtaining a generalization of the result of A. Kushkuley and Z. Balanov [40]
69

Teorida de G-índice e grau de aplicações G-equivariantes / G-index theory and degree of G-equivariant maps

Norbil Leodan Cordova Neyra 07 May 2010 (has links)
Antes da publicação do trabalho An ideal-valued cohomological index theory with applications to Borsuk-Ulam and Bourgin-Yang theorems\"de Fadell e Husseini [20], haviam sido apenas considerados índices numéricos de G-espaços, nos casos G =\'Z IND. 2\' e G um grupo finito. No entanto, tais índices numéricos são obviamente insuficientes no caso de grupos mais complexos, como por exemplo a 1-esfera \'S POT. 1\'. Neste contexto, Fadell e Husseini introduziram o chamado Indice cohomológico de valor ideal: a cada G-espaço X paracompacto, eles associaram um ideal \'Ind POT. G\' (X;K) do anel de cohomología H*(BG;K), onde a cohomologia de Cech H* é considerada com coeficientes em um corpo K e BG é o espaço classificante do grupo G. Além disso, Fadell e Husseini associaram a este ideal o Índice cohomológico de valor numérico, o qual é definido como sendo a dimensão do K-espaço vetorial obtido do quociente entre o anel H*(BG;K) e o ideal \'Ind POT. G\' (X;K). O objetivo principal deste trabalho é apresentar um estudo detalhado deste índice e utilizá-lo no estudo dos resultados sobre grau de aplicações G-equivariantes provados por Hara em \"The degree of equivariant maps\"[24] / Before the appearance of the paper An ideal-valued cohomological index theory with applications to Borsuk-Ulam and Bourgin-Yang theorems\"of Fadell and Husseini [20], had been considered numerical indices of G-spaces, when G = \'Z IND. 2\' and when G is a finite group. However, such numerical indices are obviously insufficient in the case of groups more complexes, for example, G =\'S POT 1\'. In this context Fadell andHusseini, introduced the called valued-ideal cohomological index: to every paracompact G-space X they associated an ideal \'Ind POT. G\' (X,K) of the cohomology ring H*(BG;K), where the Cech cohomology H* is considered with coefficients in a field K and BG is the classifying space of the group G. Moreover, they associated to this ideal the numerical valued cohomological index, that is, the dimension of K-vector space obtained by the quotient between the ring H*(BG;K) and the ideal \'Ind POT. G\' (X,K). The main objective of this work is to present a detailed study of this index and use such index on the study of results on degree of equivariant maps proved by Hara in his paper The degree of equivariant maps\"[24]
70

Convergence asymptotique des niveaux de temps quasi-concaves dans un espace temps à courbure constante / Asymptomatic convergence of level sets of quasi-concave times in a space-time of constant curvature

Belraouti, Mehdi 20 June 2013 (has links)
Dans cette thèse, nous nous intéressons aux espaces temps dit globalement hyperboliques Cauchy compacts. Ce sont des espaces temps qui admettent une fonction, dite fonction temps de Cauchy, propre qui croit strictement le long des courbes causales inextensibles. Les niveaux de telles fonctions sont des hypersurfaces de type espace appelées hypersurfaces de Cauchy. La donnée d'une fonction temps définit naturellement une famille à 1-paramètres d'espaces métriques. Notre but est d'étudier le comportement asymptomatique de ces familles d'espaces métriques Il y a deux cas de figure à considérer : le premier étant le comportement asymptomatique dans le passé ; le deuxième est celui du comportement asymptomatique dans le futur. Plus de conditions géométriques sur l'espace temps et les fonctions temps à considérer seront nécessaires / In this thesis we're interested in globally hyperbolic Cauchy compact space-times. These are space-times that possess a proper function, called Cauchy time function, which ist strictly increasing along inextensible causal curves. A Cauchy time function defines naturally a 1-parameter family of metric spaces. One asks the natural and important question of the asymptomatic behaviour of this family with respect to the time : when time goes to 0 and when it goes towards infinity. Of course additional geometric condition on the space-ime and the time function will be necessary for a more appropriate study

Page generated in 0.0584 seconds