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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.
21

Constructions of Lie Groupoids

Li, Travis Songhao 10 January 2014 (has links)
In this thesis, we develop two methods for constructing Lie groupoids. The first method is a blow-up construction, corresponding to the elementary modification of a Lie algebroid along a subalgebroid over some closed hypersurface. This construction may be specialized to the Poisson groupoids and Lie bialgebroids. We then apply this method to three cases. The first is the adjoint Lie groupoid integrating the Lie algebroid of vector fields tangent to a collection of normal crossing hypersurfaces. The second is the adjoint symplectic groupoid of a log symplectic manifold. The third is the adjoint Lie groupoid integrating the tangent algebroid of a Riemann surface twisted by a divisor. The second method is a gluing construction, whereby Lie groupoids defined on the open sets of an appropriate cover may be combined to obtain global integrations. This allows us to construct and classify the Lie groupoids integrating the given Lie algebroid. We apply this method to the aforementioned cases, albeit with small differences, and characterize the category of integrations in each case.
22

Geometric Structures on Spaces of Weighted Submanifolds

Lee, Brian C. 24 September 2009 (has links)
In this thesis we use a diffeo-geometric framework based on manifolds hat are locally modeled on ``convenient'' vector spaces to study the geometry of some infinite dimensional spaces. Given a finite dimensional symplectic manifold M, we construct a weak symplectic structure on each leaf I_w of a foliation of the space of compact oriented isotropic submanifolds in M equipped with top degree forms of total measure 1. These forms are called weightings and such manifolds are said to be weighted. We show that this symplectic structure on the particular leaves consisting of weighted Lagrangians is equivalent to a heuristic weak symplectic structure of Weinstein. When the weightings are positive, these symplectic spaces are symplectomorphic to reductions of a weak symplectic structure of Donaldson on the space of embeddings of a fixed compact oriented manifold into M. When M is compact, by generalizing a moment map of Weinstein we construct a symplectomorphism of each leaf I_w consisting of positive weighted isotropics onto a coadjoint orbit of the group of Hamiltonian symplectomorphisms of M equipped with the Kirillov-Kostant-Souriau symplectic structure. After defining notions of Poisson algebras and Poisson manifolds, we prove that each space I_w can also be identified with a symplectic leaf of a Poisson structure. Finally, we discuss a kinematic description of spaces of weighted submanifolds.
23

Pre-quantization of the Moduli Space of Flat G-bundles

Krepski, Derek 18 February 2010 (has links)
This thesis studies the pre-quantization of quasi-Hamiltonian group actions from a cohomological viewpoint. The compatibility of pre-quantization with symplectic reduction and the fusion product are established, and are used to understand the necessary and sufficient conditions for the pre-quantization of M(G,S), the moduli space of at flat G-bundles over a closed surface S. For a simply connected, compact, simple Lie group G, M(G,S) is known to be pre-quantizable at integer levels. For non-simply connected G, however, integrality of the level is not sufficient for pre-quantization, and this thesis determines the obstruction, namely a certain 3-dimensional cohomology class, that places further restrictions on the underlying level. The levels that admit a pre-quantization of the moduli space are determined explicitly for all non-simply connected, compact, simple Lie groups G. Partial results are obtained for the case of a surface S with marked points. Also, it is shown that via the bijective correspondence between quasi-Hamiltonian group actions and Hamiltonian loop group actions, the corresponding notions of prequantization coincide.
24

The Development of the boson calculus for the orthogonal and symplectic groups /

Lohe, Max Adolph. Unknown Date (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Mathematical Physics, 1974. / Includes bibliographical references (leaves 154-158).
25

Weil Representation and Central Extensions of Loop Symplectic Groups

Bergeron-Legros, Gabriel January 2014 (has links)
In this thesis, we present the Weil representation over loop symplectic groups. Then we study the question of whether or not the Schrodinger representation and the Weil representation are continuous. Finally, we define a cocycle of the rank 2 symplectic group, adapt Kubota's theorem to this case and verify that it splits over a subgroup.
26

Symplectic analysis of flexible structures by finite elements

毛生根, Mao, Shenggen. January 1996 (has links)
published_or_final_version / Civil and Structural Engineering / Doctoral / Doctor of Philosophy
27

Long-term dynamics of small bodies in the solar system using mapping techniques

Kehoe, Thomas James Joseph January 1999 (has links)
No description available.
28

Symplectic Integration of Nonseparable Hamiltonian Systems

Curry, David M. (David Mason) 05 1900 (has links)
Numerical methods are usually necessary in solving Hamiltonian systems since there is often no closed-form solution. By utilizing a general property of Hamiltonians, namely the symplectic property, all of the qualities of the system may be preserved for indefinitely long integration times because all of the integral (Poincare) invariants are conserved. This allows for more reliable results and frequently leads to significantly shorter execution times as compared to conventional methods. The resonant triad Hamiltonian with one degree of freedom will be focused upon for most of the numerical tests because of its difficult nature and, moreover, analytical results exist whereby useful comparisons can be made.
29

Floer homology on symplectic manifolds.

January 2008 (has links)
Kwong, Kwok Kun. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 105-109). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Introduction --- p.1 / Chapter 1 --- Morse Theory --- p.4 / Chapter 1.1 --- Introduction --- p.4 / Chapter 1.2 --- Morse Homology --- p.11 / Chapter 2 --- Symplectic Fixed Points and Arnold Conjecture --- p.24 / Chapter 2.1 --- Introduction --- p.24 / Chapter 2.2 --- The Variational Approach --- p.29 / Chapter 2.3 --- Action Functional and Moduli Space --- p.30 / Chapter 2.4 --- Construction of Floer Homology --- p.42 / Chapter 3 --- Fredholm Theory --- p.46 / Chapter 3.1 --- Fredholm Operator --- p.47 / Chapter 3.2 --- The Linearized Operator --- p.48 / Chapter 3.3 --- Maslov Index --- p.50 / Chapter 3.4 --- Fredholm Index --- p.57 / Chapter 4 --- Floer Homology --- p.75 / Chapter 4.1 --- Transversality --- p.75 / Chapter 4.2 --- Compactness and Gluing --- p.76 / Chapter 4.3 --- Floer Homology --- p.88 / Chapter 4.4 --- Invariance of Floer Homology --- p.90 / Chapter 4.5 --- An Isomorphism Theorem --- p.98 / Chapter 4.6 --- Further Applications --- p.103 / Bibliography --- p.105
30

Stability of the center of the integral group rings over finite fields

January 2019 (has links)
archives@tulane.edu / We investigate the structure constants of the center of the integral group algebra of symplectic group rings over finite fields. The reflection length on the general linear group induces a filtration on these algebras. We prove that the structure constants of the associated filtered algebra are independent of n. / 1 / Safak Ozden

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