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  • 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.
41

Decomposição celular de variedades Grassmannianas via teoria de Morse

Sullca, Alberth John Nuñez 17 March 2017 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-17T20:39:18Z No. of bitstreams: 1 alberthjohnnunezsullca.pdf: 789070 bytes, checksum: 6fff839362c420dcaaaf67f1f9975a5e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-18T13:51:59Z (GMT) No. of bitstreams: 1 alberthjohnnunezsullca.pdf: 789070 bytes, checksum: 6fff839362c420dcaaaf67f1f9975a5e (MD5) / Made available in DSpace on 2017-04-18T13:52:00Z (GMT). No. of bitstreams: 1 alberthjohnnunezsullca.pdf: 789070 bytes, checksum: 6fff839362c420dcaaaf67f1f9975a5e (MD5) Previous issue date: 2017-03-17 / Apresentamos neste trabalho uma decomposição celular CW das variedades Grassmannianas via teoria de Morse. Isto é feito de duas maneiras distintas por meio de representações matriciais das Grassmannianas chamadas modelo projeção e modelo reflexão. Definimos funções de Morse, a saber, uma função do tipo altura e uma função do tipo “distância ao quadrado”, respectivamente, para cada um dos modelos projeção e reflexão. Estudamos os seus pontos críticos e os índices dos mesmos, obtendo assim duas formas para calcular a decomposição celular CW. Em particular, no modelo projeção, isto é feito exibindo-se as curvas integrais associadas ao campo gradiente da função altura. / We present in this work a CW cellular decomposition of Grassmannian varieties via Morse theory. This is done in two different ways. By means of matrix representations of Grassmannian called model projection and reflection model. We define Morse functions, namely a height-type function and a "square-distance" function, respectively, for each of the projection and reflection models. We study their critical points and their indices, thus obtaining two ways to calculate the CW cellular decomposition. In particular, in the projection model, this is done by displaying the integral curves associated with the gradient field of the height function.
42

Transition matrix theory = Teoria da matriz de transição / Teoria da matriz de transição

Vieira, Ewerton Rocha, 1987- 03 May 2015 (has links)
Orientador: Ketty Abaroa de Rezende / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação Científica / Made available in DSpace on 2018-08-26T22:09:01Z (GMT). No. of bitstreams: 1 Vieira_EwertonRocha_D.pdf: 1632095 bytes, checksum: 5dc3208efc5649260ca62805c3e8e1b6 (MD5) Previous issue date: 2015 / Resumo: Nessa tese, apresentamos uma unificação da teoria das matrizes de transição algébrica, singular, topológica e direcional ao introduzir a matriz de transição (generalizada), a qual engloba todas as quatros citadas anteriormente. Alguns resultados de existência são apresentados bem como a verificação de que cada matriz de transição supracitada são casos particulares da matriz de transição (generalizada). Além disso, nós abordamos como as aplicações das quatros matrizes de transiçao, na teoria do índice de Conley, se traduzem para a matriz de transição (generalizada). Quando a matriz de transição (generalizada) satisfizer o requerimento adicional de cobrir o isomorfismo do índice de Conley F definido pelo fluxo, pode-se provar propriedades de existência e de conexão de órbitas. Essa matriz de transição com a propriedade de cobrir o isomorfismo F é definida como matriz de transição topológica generalizada e a utilizamos para obter conexões de órbitas num fluxo Morse-Smale sem órbitas periódicas bem como para obter conexões de órbitas numa continuação associada à sequência espectral dinâmica / Abstract: In this thesis, we present a unification of the theory of algebraic, singular, topological and directional transition matrices by introducing the (generalized) transition matrix which encompasses each of the previous four. Some transition matrix existence results are presented as well as the verification that each of the previous transition matrices are cases of the (generalized) transition matrix. Furthermore, we address how applications of the previous transition matrices to the Conley Index theory carry over to the (generalized) transition matrix. When this more general transition matrix satisfies the additional requirement that it covers flow-defined Conley-index isomorphisms, one proves algebraic and connection-existence properties. These general transition matrices with this covering property are referred to as generalized topological transition matrices and are used to consider connecting orbits of Morse-Smale flows without periodic orbits, as well as those in a continuation associated to a dynamical spectral sequence / Doutorado / Matematica / Doutor em Matemática
43

Generalizations of discrete Morse theory

Yaptieu Djeungue, Odette Sylvia 02 February 2018 (has links)
We generalize Forman’s discrete Morse theory, on one end by developing a discrete analogue of Morse-Bott theory for CW complexes, motivated by Morse-Bott theory in the smooth setting. On the other, motivated by J-N. Corvellec’s Morse theory for continuous functionals, we generalize Forman’s discrete Morse-floer theory by considering a vector field more general than the one extracted from a discrete Morse function, and defining a boundary operator from which the Betti numbers of the CW complex are obtained. We also do some Conley theory analysis.
44

Homologie de morse et théorème de la signature

St-Pierre, Alexandre January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.
45

Bott\'s periodicity theorem from the algebraic topology viewpoint / O teorema da periodicidade de Bott sob o olhar da topologia algébrica

Bonatto, Luciana Basualdo 23 August 2017 (has links)
In 1970, Raoul Bott published The Periodicity Theorem for the Classical Groups and Some of Its Applications, in which he uses this famous result as a guideline to present some important areas and tools of Algebraic Topology. This dissertation aims to use the path Bott presented in his article as a guideline to address certain topics on Algebraic Topology. We start this incursion developing important tools used in Homotopy Theory such as spectral sequences and Eilenberg-MacLane spaces, exploring how they can be combined to aid in computation of homotopy groups. We then study important results of Morse Theory, a tool which was in the centre of Botts proof of the Periodicity Theorem. We also develop two extensions: Morse-Bott Theory, and the applications of such results to the loopspace of a manifold. We end by giving an introduction to generalised cohomology theories and K-Theory. / Em 1970, Raoul Bott publicou o artigo The Periodicity Theorem for the Classical Groups and Some of Its Applications no qual usava esse famoso resultado como um guia para apresentar importantes áreas e ferramentas da Topologia Algébrica. O presente trabalho usa o mesmo caminho traçado por Bott em seu artigo como roteiro para explorar tópicos importantes da Topologia Algébrica. Começamos esta incursão desenvolvendo ferramentas importantes da Teoria de Homotopia como sequências espectrais e espaços de Eilenberg-MacLane, explorando como estes podem ser combinados para auxiliar em cálculos de grupos de homotopia. Passamos então a estudar resultados importantes de Teoria de Morse, uma ferramenta que estava no centro da demonstração de Bott do Teorema da Periodicidade. Desenvolvemos ainda, duas extensões: Teoria de Morse-Bott e aplicações destes resultados ao espaço de laços de uma variedade. Terminamos com uma introdução a teorias de cohomologia generalizadas e K-Teoria.
46

Simplicial Complexes of Graphs

Jonsson, Jakob January 2005 (has links)
Let G be a finite graph with vertex set V and edge set E. A graph complex on G is an abstract simplicial complex consisting of subsets of E. In particular, we may interpret such a complex as a family of subgraphs of G. The subject of this thesis is the topology of graph complexes, the emphasis being placed on homology, homotopy type, connectivity degree, Cohen-Macaulayness, and Euler characteristic. We are particularly interested in the case that G is the complete graph on V. Monotone graph properties are complexes on such a graph satisfying the additional condition that they are invariant under permutations of V. Some well-studied monotone graph properties that we discuss in this thesis are complexes of matchings, forests, bipartite graphs, disconnected graphs, and not 2-connected graphs. We present new results about several other monotone graph properties, including complexes of not 3-connected graphs and graphs not coverable by p vertices. Imagining the vertices as the corners of a regular polygon, we obtain another important class consisting of those graph complexes that are invariant under the natural action of the dihedral group on this polygon. The most famous example is the associahedron, whose faces are graphs without crossings inside the polygon. Restricting to matchings, forests, or bipartite graphs, we obtain other interesting complexes of noncrossing graphs. We also examine a certain "dihedral" variant of connectivity. The third class to be examined is the class of digraph complexes. Some well-studied examples are complexes of acyclic digraphs and not strongly connected digraphs. We present new results about a few other digraph complexes, including complexes of graded digraphs and non-spanning digraphs. Many of our proofs are based on Robin Forman's discrete version of Morse theory. As a byproduct, this thesis provides a loosely defined toolbox for attacking problems in topological combinatorics via discrete Morse theory. In terms of simplicity and power, arguably the most efficient tool is Forman's divide and conquer approach via decision trees, which we successfully apply to a large number of graph and digraph complexes. / QC 20100622
47

Homologie de morse et théorème de la signature

St-Pierre, Alexandre January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
48

[en] GEOMETRIC DISCRETE MORSE COMPLEXES / [pt] COMPLEXOS DE MORSE DISCRETOS E GEOMÉTRICOS

THOMAS LEWINER 26 October 2005 (has links)
[pt] A geometria diferencial descreve de maneira intuitiva os objetos suaves no espaço. Porém, com a evolução da modelagem geométrica por computador, essa ferramenta se tornou ao mesmo tempo necessária e difícil de se descrever no mundo discreto. A teoria de Morse ficou importante pela ligação que ela cria entre a topologia e a geometria diferenciais. Partindo de um ponto de vista mais combinatório, a teoria de Morse discreta de Forman liga de forma rigorosa os objetos discretos à topologia deles, abrindo essa teoria para estruturas discretas. Este trabalho propõe uma definição construtiva de funções de Morse geométricas no mundo discreto e do complexo de Morse-Smale correspondente, onde a geometria é definida como a amostragem de uma função suave nos vértices da estrutura discreta. Essa construção precisa de cálculos de homologia que se tornaram por si só uma melhoria significativa dos métodos existentes. A decomposição de Morse- Smale resultante pode ser eficientemente computada e usada para aplicações de cálculo da persistência, geração de grafos de Reeb, remoção de ruído e mais. . . / [en] Differential geometry provides an intuitive way of understanding smooth objects in the space. However, with the evolution of geometric modeling by computer, this tool became both necessary and difficult to transpose to the discrete setting. The power of Morse theory relies on the link it created between differential topology and geometry. Starting from a combinatorial point of view, Forman´s discrete Morse theory relates rigorously discrete objects to their topology, opening Morse theory to discrete structures. This work proposes a constructive definition of geometric discrete Morse functions and their corresponding discrete Morse-Smale complexes, where the geometry is defined as a smooth function sampled on the vertices of the discrete structure. This construction required some homology computations that turned out to be a significant improvement over existing methods by itself. The resulting Morse-Smale decomposition can then be efficiently computed, and used for applications to persistence computation, Reeb graph generation, noise removal. . .
49

Bott\'s periodicity theorem from the algebraic topology viewpoint / O teorema da periodicidade de Bott sob o olhar da topologia algébrica

Luciana Basualdo Bonatto 23 August 2017 (has links)
In 1970, Raoul Bott published The Periodicity Theorem for the Classical Groups and Some of Its Applications, in which he uses this famous result as a guideline to present some important areas and tools of Algebraic Topology. This dissertation aims to use the path Bott presented in his article as a guideline to address certain topics on Algebraic Topology. We start this incursion developing important tools used in Homotopy Theory such as spectral sequences and Eilenberg-MacLane spaces, exploring how they can be combined to aid in computation of homotopy groups. We then study important results of Morse Theory, a tool which was in the centre of Botts proof of the Periodicity Theorem. We also develop two extensions: Morse-Bott Theory, and the applications of such results to the loopspace of a manifold. We end by giving an introduction to generalised cohomology theories and K-Theory. / Em 1970, Raoul Bott publicou o artigo The Periodicity Theorem for the Classical Groups and Some of Its Applications no qual usava esse famoso resultado como um guia para apresentar importantes áreas e ferramentas da Topologia Algébrica. O presente trabalho usa o mesmo caminho traçado por Bott em seu artigo como roteiro para explorar tópicos importantes da Topologia Algébrica. Começamos esta incursão desenvolvendo ferramentas importantes da Teoria de Homotopia como sequências espectrais e espaços de Eilenberg-MacLane, explorando como estes podem ser combinados para auxiliar em cálculos de grupos de homotopia. Passamos então a estudar resultados importantes de Teoria de Morse, uma ferramenta que estava no centro da demonstração de Bott do Teorema da Periodicidade. Desenvolvemos ainda, duas extensões: Teoria de Morse-Bott e aplicações destes resultados ao espaço de laços de uma variedade. Terminamos com uma introdução a teorias de cohomologia generalizadas e K-Teoria.
50

Multiplicidade de soluções para equação de quarta ordem / Multiplicity of solutions for fourth order equation

Monteiro, Evandro, 1982- 10 April 2011 (has links)
Orientador: Djairo Guedes de Figueiredo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica / Made available in DSpace on 2018-08-18T23:11:17Z (GMT). No. of bitstreams: 1 Monteiro_Evandro_D.pdf: 681089 bytes, checksum: 5ec4729a2d7b386329193adf424f6b42 (MD5) Previous issue date: 2011 / Resumo: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The complete abstract is available with the full electronic digital thesis or dissertations / Doutorado / Matematica / Doutor em Matemática

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