Spelling suggestions: "subject:"principal bundle""
1 |
Tipos de homotopia dos grupos de gauge dos fibrados linhas quaterniônicos sobre esferas / Homotopy type of Gauge groups of quaternionic line bundles over spheresClaudio, Mario Henrique Andrade 12 June 2008 (has links)
Seja p um \'S POT. 3\' - fibrado principal sobre uma esfera \'S POT. n\' , com n \' >OU=\' 4 . O objetivo deste trabalho é calcular os tipos de homotopia do grupo de gauge \'G IND. p\' desses fibrados p, estendendo o resultado determinado por A. Kono [25] quando n = 4. Apresentamos fórmulas explícitas para o operador bordo na seqüência exata de homotopia associada com a aplicação avaliação ev : m(\'S POT. n\' , B \'S POT. 3\' ) \'SETA\' B \'S POT. 3\' , traduzindo o problema nos cálculos envolvendo grupos de homotopia de esferas. Calculamos todos os casos clássicos, ou seja, aqueles que podem ser avaliados usando as informações encontradas no livro de H. Toda [46], determinando o tipo de homotopia do grupo de gauge desses fibrados para cada n \' > OU =\' 25 / Let p be a principal \'S POT. 3\' - bundle over a sphere \'S POT. n\' , with n\' > or =\' 4\'. The subject of this work is to calculate the homotopy type of the gauge group \'G IND. p\' of these bundles p, extending the result determined by A. Kono [25] when n = 4. We present explicit formulas for the boundary operator in the homotopy exact sequence associated with the evaluation map ev : m(\'S POT. n\' , B \'S POT. 3\' ) \' ARROW\' B \'S POT. 3\' , translating that problem into calculations involving homotopy groups of sphere. We calculate all the classical cases, namely those that can be dealt with using the information in the book of H. Toda [46], determining the homotopy type of the gauge group of these bundles for each n \'> or = 25
|
2 |
Tipos de homotopia dos grupos de gauge dos fibrados linhas quaterniônicos sobre esferas / Homotopy type of Gauge groups of quaternionic line bundles over spheresMario Henrique Andrade Claudio 12 June 2008 (has links)
Seja p um \'S POT. 3\' - fibrado principal sobre uma esfera \'S POT. n\' , com n \' >OU=\' 4 . O objetivo deste trabalho é calcular os tipos de homotopia do grupo de gauge \'G IND. p\' desses fibrados p, estendendo o resultado determinado por A. Kono [25] quando n = 4. Apresentamos fórmulas explícitas para o operador bordo na seqüência exata de homotopia associada com a aplicação avaliação ev : m(\'S POT. n\' , B \'S POT. 3\' ) \'SETA\' B \'S POT. 3\' , traduzindo o problema nos cálculos envolvendo grupos de homotopia de esferas. Calculamos todos os casos clássicos, ou seja, aqueles que podem ser avaliados usando as informações encontradas no livro de H. Toda [46], determinando o tipo de homotopia do grupo de gauge desses fibrados para cada n \' > OU =\' 25 / Let p be a principal \'S POT. 3\' - bundle over a sphere \'S POT. n\' , with n\' > or =\' 4\'. The subject of this work is to calculate the homotopy type of the gauge group \'G IND. p\' of these bundles p, extending the result determined by A. Kono [25] when n = 4. We present explicit formulas for the boundary operator in the homotopy exact sequence associated with the evaluation map ev : m(\'S POT. n\' , B \'S POT. 3\' ) \' ARROW\' B \'S POT. 3\' , translating that problem into calculations involving homotopy groups of sphere. We calculate all the classical cases, namely those that can be dealt with using the information in the book of H. Toda [46], determining the homotopy type of the gauge group of these bundles for each n \'> or = 25
|
3 |
Equivariant Principal Bundles over the 2-SphereYALCINKAYA, EYUP January 2012 (has links)
<p>Isotropy representations provide powerful tools for understanding the classification of equivariant principal bundles over the $2$-sphere. We consider a $\Gamma$-equivariant principal $G$-bundle over $S^2$ with structural group $G$ a compact connected Lie group, and $\Gamma \subset SO(3)$ a finite group acting linearly on $S^2.$ Let $X$ be a topological space and $\Gamma$ be a group acting on $X.$ An isotropy subgroup is defined by $\Gamma_x = \{\gamma \in \Gamma \lvert \gamma x=x\}.$ Assume $X$ is a $\Gamma$-space and $A$ is the orbit space of $X$. Let $\varphi: A\rightarrow X$ be a continuous map with $\pi \circ \varphi = 1_A$. An isotropy groupoid is defined by $\mathfrak{I} = \{(\gamma,a) \in \Gamma\times A \lvert \ \gamma \in \Gamma_{\varphi(a)}\}.$ An isotropy representation of $\mathfrak{I}$ is a continuous map $\iota : \mathfrak{I} \rightarrow G$ such that the restriction map $\mathfrak{I}_a \rightarrow G$ is a group homomorphism. $\Gamma$- equivariant principal $G$-bundles are studied in two steps; \begin{enumerate} [1)] \item the restriction of an equivariant bundle to the $\Gamma$ equivariant 1-skeleton $X \subset S^2$ where $\mathfrak{I}$ is isotropy representation of $X$ over singular set of the $\Gamma$-sets in $S^2$ \item the underlying $G$-bundle $\xi$ over $S^2$ determined by $c(\xi)\in \pi_2(BG).$ \end{enumerate}</p> / Master of Science (MSc)
|
4 |
Ga-actions on Complex Affine ThreefoldsHedén, Isac January 2013 (has links)
This thesis consists of two papers and a summary. The papers both deal with affine algebraic complex varieties, and in particular such varieties in dimension three that have a non-trivial action of one of the one-dimensional algebraic groups Ga := (C, +) and Gm := (C*, ·). The methods used involve blowing up of subvarieties, the correspondances between Ga - and Gm - actions on an affine variety X with locally nilpotent derivations and Z-gradings respectively on O(X) and passing from a filtered algebra A to its associated graded algebra gr(A). In Paper I, we study Russell’s hypersurface X , i.e. the affine variety in the affine space A4 given by the equation x + x2y + z3 + t2 = 0. We reprove by geometric means Makar-Limanov’s result which states that X is not isomorphic to A3 – a result which was crucial to Koras-Russell’s proof of the linearization conjecture for Gm -actions on A3. Our method consist in realizing X as an open part of a blowup M −→ A3 and to show that each Ga -action on X descends to A3 . This follows from considerations of the graded algebra associated to O(X ) with respect to a certain filtration. In Paper II, we study Ga-threefolds X which have as their algebraic quotient the affine plane A2 = Sp(C[x, y]) and are a principal bundle above the punctured plane A2 := A2 \ {0}. Equivalently, we study affine Ga -varieties Pˆ that extend a principal bundle P over A2, being P together with an extra fiber over the origin in A2. First the trivial bundle is studied, and some examples of extensions are given (including smooth ones which are not isomorphic to A2 × A). The most basic among the non-trivial principal bundles over A2 is SL2 (C) −→ A2, A 1→ Ae1 where e1 denotes the first unit vector, and we show that any non-trivial bundle can be realized as a pullback of this bundle with respect to a morphism A2 −→ A2. Therefore the attention is then restricted to extensions of SL2(C) and find two families of such extensions via a study of the graded algebras associated with the coordinate rings O(Pˆ) '→ O(P ) with respect to a filtration which is defined in terms of the Ga -actions on P and Pˆ respectively.
|
5 |
Uma generalização de pseudogrupo estruturas / A generalization of pseudogroup structuresGenaro Pablo Zamudio Chauca 20 April 2018 (has links)
Já é bem estabelecido na geometria diferencial o uso de fibrados principais com grupo de estru- tura para a definição e o estudo de algumas estruturas geométricas na base do fibrado. O uso de fibrados principais com grupoide de estrutura na definição de estruturas geométricas sobre varieda- des não tem sido muito explorada. O único exemplo do uso desses fibrados para definir estruturas geométricas foi dado Haefliger. Ele mostrou que folheações regulares sobre uma variedade estão em correspondência com uma classe de fibrados principais com grupoide de estrutura, e usando a classificação de fibrados principais ele obtive a classificação de folheações regulares a menos de homotopia sobre uma variedade aberta. Neste trabalho propomos uma definição a qual generaliza as folheações regulares para produzir uma classe de fibrados vetoriais ancorados e provamos para eles um teorema de classificação no espirito do teorema de Haefliger. Depois aplicamos a teoria desenvolvida aos grupoides com formas multiplicativas e mostramos como a nossa definição per- mite trasladar a geometria guardada na forma multiplicativa para a base do fibrado principal. Em seguida voltamos para o caso de folheações regulares e mostramos que a nossa proposta permite incluir novas estruturas transversais à folheação. / It is well know in differencial geometry the use of principal bundles with structure group to define and study some geometric structures on the base of the bundle. The use of principal bun- dle with a structure groupoid has not been extensively studied yet. The only example using this kind of bundle was provided by Haefliger in his study of regular foliations. Haefliger showed that regular foliations can be identified with some class of principal bundles with structure groupoid, then by using the classifying theorem of principal bundles he arrived to the classification theorem of regular foliations up to homotopy on open manifolds. In this work we will propose a definition that generalizes regular foliations to include anchored vector bundles and, will prove a classification theorem for these structures in the spirit of Haefligers theorem. Then we will apply this theory to groupoids with multiplicative forms and show that our definition permits to transfer the geometry encoded in the multiplicative form to the base of the bundle. Then we will back to the case of regular foliations and show that our proposal allow new transversal structures to the foliation.
|
6 |
Uma generalização de pseudogrupo estruturas / A generalization of pseudogroup structuresChauca, Genaro Pablo Zamudio 20 April 2018 (has links)
Já é bem estabelecido na geometria diferencial o uso de fibrados principais com grupo de estru- tura para a definição e o estudo de algumas estruturas geométricas na base do fibrado. O uso de fibrados principais com grupoide de estrutura na definição de estruturas geométricas sobre varieda- des não tem sido muito explorada. O único exemplo do uso desses fibrados para definir estruturas geométricas foi dado Haefliger. Ele mostrou que folheações regulares sobre uma variedade estão em correspondência com uma classe de fibrados principais com grupoide de estrutura, e usando a classificação de fibrados principais ele obtive a classificação de folheações regulares a menos de homotopia sobre uma variedade aberta. Neste trabalho propomos uma definição a qual generaliza as folheações regulares para produzir uma classe de fibrados vetoriais ancorados e provamos para eles um teorema de classificação no espirito do teorema de Haefliger. Depois aplicamos a teoria desenvolvida aos grupoides com formas multiplicativas e mostramos como a nossa definição per- mite trasladar a geometria guardada na forma multiplicativa para a base do fibrado principal. Em seguida voltamos para o caso de folheações regulares e mostramos que a nossa proposta permite incluir novas estruturas transversais à folheação. / It is well know in differencial geometry the use of principal bundles with structure group to define and study some geometric structures on the base of the bundle. The use of principal bun- dle with a structure groupoid has not been extensively studied yet. The only example using this kind of bundle was provided by Haefliger in his study of regular foliations. Haefliger showed that regular foliations can be identified with some class of principal bundles with structure groupoid, then by using the classifying theorem of principal bundles he arrived to the classification theorem of regular foliations up to homotopy on open manifolds. In this work we will propose a definition that generalizes regular foliations to include anchored vector bundles and, will prove a classification theorem for these structures in the spirit of Haefligers theorem. Then we will apply this theory to groupoids with multiplicative forms and show that our definition permits to transfer the geometry encoded in the multiplicative form to the base of the bundle. Then we will back to the case of regular foliations and show that our proposal allow new transversal structures to the foliation.
|
7 |
Geometrické struktury a objekty z hlediska aplikací v mechanice / Geometrical structures and objects from the point of view of their applications in mechanicsAmbrozková, Anna January 2020 (has links)
This Master's thesis relates to continuum mechanics and its connection with selected directions of modern differential geometry, which deal with geometric structures and objects. These are mainly tensors, bundles, varieties and jets. The first part is devoted to the mechanics of the continuum itself and its description in several areas, others deal with mathematical concepts and their possible application in mechanics.
|
Page generated in 0.062 seconds