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Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators

The purpose of this work is to explore some notions of monotonicity for operators between Banach spaces and the applications to the study of boundary value problems (BVPs) and initial boundary value problems (IBVPs) for partial differential equations (PDEs), with the possibility in the end to examin...

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Main Author: Lin, Tianyu
Other Authors: Ebobisse, Bille Francois
Format: Thesis
Language:English
Published: Department of Mathematics and Applied Mathematics 2021
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access_status_str Open Access
author Lin, Tianyu
author2 Ebobisse, Bille Francois
author_browse Ebobisse, Bille Francois
Lin, Tianyu
author_facet Ebobisse, Bille Francois
Lin, Tianyu
author_sort Lin, Tianyu
collection Thesis
description The purpose of this work is to explore some notions of monotonicity for operators between Banach spaces and the applications to the study of boundary value problems (BVPs) and initial boundary value problems (IBVPs) for partial differential equations (PDEs), with the possibility in the end to examine new problems and provide some solutions. Variational approach will be used to reformulate these problems into stationary equations (in the case of BVPs) and evolution equations (in the case of IBVPs), where the underlined operators constructed as realizations of those problems in appropriate function spaces. This is known as weak formulation, which allows us to find weak solutions of the problems in a larger functions space rather than classical solutions that are sufficiently smooth. The theory of monotone and pseudomonotone operators will be applied to find existence theorems for stationary equations and evolution equations. In addition, the existence theorem for evolution equations with locally monotone operator will also be presented as a generalisation of the one with monotone operators. Another type of monotonicity so-called strict p-quasimonotonicity, which is defined in term of Young measures. This type of weaker, integrated version of monotonicity is directly applied in the study of elliptic and parabolic system of PDEs, the difficulty arises from dealing with this monotonicity is overcome by the theory of Young measures. The application of these monotonicity in the study of variational inequality will also be discussed. In particular, there is a new setting for strict p-quasimonotonicity in a particular type of elliptic variational inequalities, the proof of the new existence theorem will also be presented. Some open problems on the application of strict p-quasimonotonicity in the study of parabolic variational inequalities will also be discussed. Finally, we mention the theory of monotone and pseudomonotone operators in the study of second order evolution equations. A new setting of the local monotonicity in the second order evolution equations will be presented as well as the new existence theorem.
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:33:23.204Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2021
publishDateRange 2021
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publisher Department of Mathematics and Applied Mathematics
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spelling oai:open.uct.ac.za:11427/32783 Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators Lin, Tianyu Ebobisse, Bille Francois Mathematics The purpose of this work is to explore some notions of monotonicity for operators between Banach spaces and the applications to the study of boundary value problems (BVPs) and initial boundary value problems (IBVPs) for partial differential equations (PDEs), with the possibility in the end to examine new problems and provide some solutions. Variational approach will be used to reformulate these problems into stationary equations (in the case of BVPs) and evolution equations (in the case of IBVPs), where the underlined operators constructed as realizations of those problems in appropriate function spaces. This is known as weak formulation, which allows us to find weak solutions of the problems in a larger functions space rather than classical solutions that are sufficiently smooth. The theory of monotone and pseudomonotone operators will be applied to find existence theorems for stationary equations and evolution equations. In addition, the existence theorem for evolution equations with locally monotone operator will also be presented as a generalisation of the one with monotone operators. Another type of monotonicity so-called strict p-quasimonotonicity, which is defined in term of Young measures. This type of weaker, integrated version of monotonicity is directly applied in the study of elliptic and parabolic system of PDEs, the difficulty arises from dealing with this monotonicity is overcome by the theory of Young measures. The application of these monotonicity in the study of variational inequality will also be discussed. In particular, there is a new setting for strict p-quasimonotonicity in a particular type of elliptic variational inequalities, the proof of the new existence theorem will also be presented. Some open problems on the application of strict p-quasimonotonicity in the study of parabolic variational inequalities will also be discussed. Finally, we mention the theory of monotone and pseudomonotone operators in the study of second order evolution equations. A new setting of the local monotonicity in the second order evolution equations will be presented as well as the new existence theorem. 2021-02-04T13:56:07Z 2021-02-04T13:56:07Z 2020 2021-02-04T05:39:44Z Master Thesis Masters MSc http://hdl.handle.net/11427/32783 eng application/pdf Department of Mathematics and Applied Mathematics Faculty of Science
spellingShingle Mathematics
Lin, Tianyu
Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
thesis_degree_str Master's
title Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
title_full Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
title_fullStr Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
title_full_unstemmed Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
title_short Some Stationary and Evolution Problems Governed by Various Notions of Monotone Operators
title_sort some stationary and evolution problems governed by various notions of monotone operators
topic Mathematics
url http://hdl.handle.net/11427/32783
work_keys_str_mv AT lintianyu somestationaryandevolutionproblemsgovernedbyvariousnotionsofmonotoneoperators