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Universal metric spaces
Raška, Martin ; Hušek, Miroslav (advisor) ; Vejnar, Benjamin (referee)
The thesis covers the properties of isometric embeddings of metric spaces into the Urysohn universal space U (P.S. Urysohn, 1927) and its generalizations (M. Katětov, 1988). The examination of various metric properties of the space U leads to the question of extendability of the embedding ϕ: M → U from a subspace M of a space P onto an embedding Φ: P → U. We approach to this question in situation P = M ∪ {p} in finer form. If ϕ denotes an embedding M → U, let Rϕ denotes the set of images of the point p in U under all possible isometric extensions of the embedding ϕ (we call Rϕ the space of realizations). The main objective of this thesis is answering the following question: Which forms do the spaces Rϕ assume, if ϕ passes all embeddings of the space M into the space U? Corollary 1 and theorem 3 in the II. part of the thesis metrically characterize the family {Rϕ|ϕ: M → U}. We use previous results in part III in order to determine the number of classes of metrically equivalent embeddings of the space M into the space U. As a consequence, we obtain the result of J. Melleray about the homogeneity of the space U.
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Universal metric spaces
Raška, Martin ; Hušek, Miroslav (advisor) ; Vejnar, Benjamin (referee)
The thesis covers the properties of isometric embeddings of metric spaces into the Urysohn universal space U (P.S. Urysohn, 1927) and its generalizations (M. Katětov, 1988). The examination of various metric properties of the space U leads to the question of extendability of the embedding ϕ: M → U from a subspace M of a space P onto an embedding Φ: P → U. We approach to this question in situation P = M ∪ {p} in finer form. If ϕ denotes an embedding M → U, let Rϕ denotes the set of images of the point p in U under all possible isometric extensions of the embedding ϕ (we call Rϕ the space of realizations). The main objective of this thesis is answering the following question: Which forms do the spaces Rϕ assume, if ϕ passes all embeddings of the space M into the space U? Corollary 1 and theorem 3 in the II. part of the thesis metrically characterize the family {Rϕ|ϕ: M → U}. We use previous results in part III in order to determine the number of classes of metrically equivalent embeddings of the space M into the space U. As a consequence, we obtain the result of J. Melleray about the homogeneity of the space U.
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Differential geometry and dynamics
Nárožný, Jiří ; Krýsl, Svatopluk (advisor) ; Scholtz, Martin (referee)
The aim of this thesis is to show some mathematical concepts and methods of differential geometry and Lie groups. Subsequently, we try to use this tools in physics. Selection of these two mathematical topics is not random, because these topics are close related essentials of theoretical physics. The thesis is split into two chapters. Each chapter fulfils one of this aim. In the first chapter we introduce the notion of group, which is further enriched with other notions, like group action or group product. This detailed and smooth process leads us to introduction of homogeneous space which is one of the most important notion of Klein geometry. The end of this chapter is devoted to brief introduction to this attitude to geometry. The second chapter consists formulation of physical tasks in the language of differential geometry and afterwards its solution. As the final topic in this thesis we introduce Jacobi connection, as more natural option of connection which is implemented to physical system. Powered by TCPDF (www.tcpdf.org)
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Grassmann and flag manifolds
Eliáš, Jakub ; Krump, Lukáš (advisor) ; Krýsl, Svatopluk (referee)
Title: Grassmann and flag manifolds Author: Jakub Eliáš Department: Matematický ústav Univerzity Karlovy Supervisor: Mgr. Lukáš Krump, Ph.D., Matematický ústav Univerzity Karlovy Abstract: This bachelor thesis deals with describing Grassmann and flag man- ifolds as smooth manifolds with their properties. In order to do so we use Lie group theory to introduce a way to construct a smooth atlas on a general quo- tient of a Lie group and its closed Lie subgroup. The thesis consists of two parts. In the first part we summarize needed basics of Lie group theory, we introduce the quotient of a Lie group and its closed Lie subgroup and describe a means how to express it as a homogeneous space. In the second part we introduce the Grassmann manifolds and flag manifolds (which we break up to complete and partial ones) and express both types of them as homogeneous spaces. Keywords: Grassmann manifold, flag manifold, homogeneous space, isotropy group 1
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