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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.
11

Uma versão parametrizada do teorema de Borsuk-Ulam / A parametrized version of the Borsuk-Ulam theorem

Silva, Nelson Antonio 18 March 2011 (has links)
O teorema clássico de Borsuk-Ulam nos dá informações à respeito de aplicações \'S POT. n\' \'SETA\' \'R POT. n\', no qual \'S POT. n\' é um \'Z IND. 2\' -espaço livre. O teorema afirma que existe pelo menos uma órbita que é enviada em um único ponto em \'R POT. n\'. Dold [9] estendeu este problema para o contexto de fibrados, considerando aplicações f : S (E) \'SETA\' \'E POT. \'prime\'\' nos quais preservam fibras; aqui, S (E) denota o espaço total do fibrado em esfera sobre B associado ao fibrado vetorial E \'SETA\' B e \'E POT. \'prime\'\' \'SETA\' B é o outro fibrado vetorial. O objetivo desse trabalho é provar esta versão do teorema de Borsuk-Ulam obtida por Dold, chamada versão parametrizada do teorema de Borsuk-Ulam. Nós também provamos uma versão cohomológica deste problema / The classical Borsuk-Ulam Theorem gives information about maps \'S POT. n\' \'ARROW\' \'R POT. n\' where \'S POT. n\' has a free action of the cyclic group \'Z IND. 2\'. The theorem states that there is at least one orbit which is sent to a single point in \'R POT. n\'. Dold [9] extended this problem to a fibre-wise setting, by considering maps f : S (E) \'ARROW\' \' E POT. prime\' which preserve fibres; here, S (E) denotes the total space of the sphere bundle associated over B to a vector bundle E \'ARROW\' B and \'E POT. prime\' \'ARROW\' B is other vector bundle over B. The purpose of this work is to prove this version of the Borsuk-Ulam theorem obtained by A. Dold, called parametrized version of the Borsuk-Ulam theorem. We also prove a cohomological generalization of this problem
12

Introdução à cohomologia de De Rham / Introduction to De Rham Cohomology

Silva, Junior Soares da 27 July 2017 (has links)
Começamos definindo a cohomologia clássica de De Rham e provamos alguns resultados que nos permitem calcular tal cohomologia de algumas variedades diferenciáveis. Com o intuito de provar o Teorema de De Rham, escolhemos fazer a demonstração utilizando a noção de feixes, que se mostra como uma generalização da ideia de cohomologia. Como a cohomologia de De Rham não é a única que se pode definir numa variedade, a questão da unicidade dá origem a teoria axiomática de feixes, que nos dará uma cohomologia para cada feixe dado. Mostraremos que a partir da teoria axiomática de feixes obtemos cohomologias, além das cohomologias clássicas de De Rham, a cohomologia clássica singular e a cohomologia clássica de Cech e mostraremos que essas cohomologias obtidas a partir da noção axiomática são isomorfas as definições clássicas. Concluiremos que se nos restringirmos a apenas variedades diferenciáveis, essas cohomologias são unicamente isomorfas e este será o teorema de De Rham. / We begin by defining De Rhams classical cohomology and we prove some results that allow us a calculation of the cohomology of some differentiable manifolds. In order to prove De Rhams Theorem, we chose to make a demonstration using a notion of sheaves, which is a generalization of the idea of cohomology. Since De Rhams cohomology is not a only one that can be made into a variety, the question of unicity gives rise to axiomatic theory of sheaves, which give us a cohomology for each sheaf given. We will show that from the axiomatic theory of sheaves we obtain cohomologies, besides the classical cohomologies of De Rham, a singular classical cohomology and a classical cohomology of Cech and we will show that cohomologies are obtained from the axiomatic notion are classic definitions. We will conclude that if we restrict ourselves to only differentiable manifolds, these cohomologies are uniquely isomorphic and this will be De Rhams theorem.
13

Uma versão parametrizada do teorema de Borsuk-Ulam / A parametrized version of the Borsuk-Ulam theorem

Nelson Antonio Silva 18 March 2011 (has links)
O teorema clássico de Borsuk-Ulam nos dá informações à respeito de aplicações \'S POT. n\' \'SETA\' \'R POT. n\', no qual \'S POT. n\' é um \'Z IND. 2\' -espaço livre. O teorema afirma que existe pelo menos uma órbita que é enviada em um único ponto em \'R POT. n\'. Dold [9] estendeu este problema para o contexto de fibrados, considerando aplicações f : S (E) \'SETA\' \'E POT. \'prime\'\' nos quais preservam fibras; aqui, S (E) denota o espaço total do fibrado em esfera sobre B associado ao fibrado vetorial E \'SETA\' B e \'E POT. \'prime\'\' \'SETA\' B é o outro fibrado vetorial. O objetivo desse trabalho é provar esta versão do teorema de Borsuk-Ulam obtida por Dold, chamada versão parametrizada do teorema de Borsuk-Ulam. Nós também provamos uma versão cohomológica deste problema / The classical Borsuk-Ulam Theorem gives information about maps \'S POT. n\' \'ARROW\' \'R POT. n\' where \'S POT. n\' has a free action of the cyclic group \'Z IND. 2\'. The theorem states that there is at least one orbit which is sent to a single point in \'R POT. n\'. Dold [9] extended this problem to a fibre-wise setting, by considering maps f : S (E) \'ARROW\' \' E POT. prime\' which preserve fibres; here, S (E) denotes the total space of the sphere bundle associated over B to a vector bundle E \'ARROW\' B and \'E POT. prime\' \'ARROW\' B is other vector bundle over B. The purpose of this work is to prove this version of the Borsuk-Ulam theorem obtained by A. Dold, called parametrized version of the Borsuk-Ulam theorem. We also prove a cohomological generalization of this problem
14

Introdução à cohomologia de De Rham / Introduction to De Rham Cohomology

Junior Soares da Silva 27 July 2017 (has links)
Começamos definindo a cohomologia clássica de De Rham e provamos alguns resultados que nos permitem calcular tal cohomologia de algumas variedades diferenciáveis. Com o intuito de provar o Teorema de De Rham, escolhemos fazer a demonstração utilizando a noção de feixes, que se mostra como uma generalização da ideia de cohomologia. Como a cohomologia de De Rham não é a única que se pode definir numa variedade, a questão da unicidade dá origem a teoria axiomática de feixes, que nos dará uma cohomologia para cada feixe dado. Mostraremos que a partir da teoria axiomática de feixes obtemos cohomologias, além das cohomologias clássicas de De Rham, a cohomologia clássica singular e a cohomologia clássica de Cech e mostraremos que essas cohomologias obtidas a partir da noção axiomática são isomorfas as definições clássicas. Concluiremos que se nos restringirmos a apenas variedades diferenciáveis, essas cohomologias são unicamente isomorfas e este será o teorema de De Rham. / We begin by defining De Rhams classical cohomology and we prove some results that allow us a calculation of the cohomology of some differentiable manifolds. In order to prove De Rhams Theorem, we chose to make a demonstration using a notion of sheaves, which is a generalization of the idea of cohomology. Since De Rhams cohomology is not a only one that can be made into a variety, the question of unicity gives rise to axiomatic theory of sheaves, which give us a cohomology for each sheaf given. We will show that from the axiomatic theory of sheaves we obtain cohomologies, besides the classical cohomologies of De Rham, a singular classical cohomology and a classical cohomology of Cech and we will show that cohomologies are obtained from the axiomatic notion are classic definitions. We will conclude that if we restrict ourselves to only differentiable manifolds, these cohomologies are uniquely isomorphic and this will be De Rhams theorem.
15

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]
16

Reconstruction en grandes dimensions

Salinas, David 11 September 2013 (has links) (PDF)
Dans cette thèse, nous cherchons à reconstruire une approximation d'une variété connue seulement à partir d'un nuage de points de grande dimension l'échantillonnant. Nous nous efforçons de trouver des méthodes de reconstructions efficaces et produisant des approximations ayant la même topologie que la variété échantillonnée. Une attention particulière est consacrée aux flag-complexes et particulièrement aux complexes de Rips. Nous montrons que le complexe de Rips capture la topologie d'une variété échantillonnée en supposant de bonnes conditions d'échantillonnage. En tirant avantage de la compacité des flags-complexes qui peuvent être représentés de manière compacte avec un graphe, nous présentons une structure de données appelée squelette/bloqueurs pour complexes simpliciaux. Nous étudions ensuite deux opérations de simplifications, la contraction d'arête et le collapse simplicial, qui s'avèrent utiles pour réduire un complexe simplicial sans en changer sa topologie.
17

Índice de Yang e teoremas generalizados

Costa, Willer Daniel da Silva 26 July 2011 (has links)
Made available in DSpace on 2016-06-02T20:28:26Z (GMT). No. of bitstreams: 1 3804.pdf: 547055 bytes, checksum: af56410714984fa20f396c4ab492dc3f (MD5) Previous issue date: 2011-07-26 / Universidade Federal de Sao Carlos / We work with T-spaces (X; T), where X is a Hausdor_ compact space and T : X ! X is a continuous involution without _xed points. Considering the sphere Sn with the antipodal map, we highlight three classical theorems relating to the T-space Sn;A): Borsuk-Ulam's theorem, Kakutani-Yamabe-Yujobô's theorem and Dyson's theorem. This dissertation consists of a detailed study of the article fo C. T. Yang (Annals of Math. 60, no. 2 (1954), 262-282) where the author introduces a concept of the index and presents, in a sense homological, generalizations of the three theorems cited above, considering any T-space. Beyond the generalizations itself, we build examples of the index calculation of some T-spaces and, still, we explore a concept of orthogonality in T-spaces. / Trabalhamos com T-espaços (X; T), em que X é um espaço compacto e Hausdor _ e T : X ! X é uma involução contínua sem pontos _xos. Considerando a esfera Sn com a aplicação antipodal, destacamos três teoremas clássicos relativos ao T-espaço (Sn;A): teorema de Borsuk-Ulam, teorema de Kakutani-Yamabe-Yujobô e teorema de Dyson. Esta dissertação consiste em um estudo detalhado do artigo de C. T. Yang (Annals of Math. 60, no. 2 (1954), 262-282) em que o autor introduz um conceito de índice e apresenta, em certo sentido homológico, generalizações dos três teoremas citados acima, considerando T-espaços quaisquer. Além das generalizações em si, construímos exemplos de cálculo de índice de alguns T-espaços e, ainda, exploramos um conceito de ortogonalidade em T-espaços.
18

Ultrafilters and Compactification

Nxumalo, Mbekezeli Sibahle January 2020 (has links)
>Magister Scientiae - MSc / In this thesis, we construct the ultrafilter space of a topological space using ultrafilters as points, study some of its properties and describe a method of generating compactifications through the ultrafilter space. As part of investigating some properties of the ultrafilter space, we show that the ultrafilter space forms a monad in the category of topological spaces. Furthermore, we show that rendering the ultrafilter space suitably separated results in a generation of separated compactifications which coincide with some well-known compactifications. When the ultrafilter space is rendered T0 or sober, the resulting compactifications is a stable Compactifications. Rendering the ultrafilter space T2 or Tychono results in the Stone_ Cechcompactification
19

Malířský cech na Novém Městě pražském v 17. a 18. století / The Painters' Guild in Prague's New Town in 17th and 18th Century

Heisslerová, Radka January 2020 (has links)
The presented dissertation deals with the history of the painter's guild of the New Town of Prague with the main emphasis on its form and development in the 17th and 18th centuries but doesn't leave aside the period of older history. The work thus focuses on New Town painters from the beginnings of the existence of their guild, through the issuance of the privilege of Emperor Rudolf II. in 1595, by which he granted the Old Town-Lesser Town painter's guild significant privileges, as a result of which the joint development of all Prague painting associations began to take different paths. The thesis also deals with the circumstances leading to the demise of the guild in the 1780s, when the Prague painters' fraternities were abolished by Emperor Joseph II. In addition to the history of the painters' association, the thesis provides an insight into the guild life of New Town painters, which it monitors in individual positions within the guild hierarchy, focuses on the functioning of the association itself, its management, material and written sources, representation of the corporation and individual members, and last but not least, it describes the way of worshiping the patron saint of painters - St. Luke. Because not only members of the guild worked as painters in the New Town of Prague, the work also...
20

Teoria de Nielsen de raízes e teoria do grau de Hopf / Nielsen Root Theory and Hopf Degree Theory

Taneda, Paulo Takashi 15 March 2007 (has links)
Neste trabalho, veremos que a noção de número de Nielsen pode ser estendida para aplicações entre variedades topológicas não necessariamente orientáveis ou compactas, com ou sem fronteira. / In this work, we are going to see that the concept of Nilsen Root Number can be extended to maps between not necessarily orientable nor compact manifolds, with or without boundary.

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