Operator Methods for Boundary Value Problems (London Mathematical Society Lecture Note Series) by Professor Seppo Hassi, Professor Hendrik S. V. de Snoo and Professor Franciszek Hugon Szafraniec
English | 2012 | ISBN: 110760611X | 309 pages | PDF | 1,5 MB
English | 2012 | ISBN: 110760611X | 309 pages | PDF | 1,5 MB
Presented in this volume are a number of new results concerning the extension theory and spectral theory of unbounded operators using the recent notions of boundary triplets and boundary relations. This approach relies on linear single-valued and multi-valued maps, isometric in a Krein space sense, and offers a basic framework for recent developments in system theory.
Central to the theory are analytic tools such as Weyl functions, including Titchmarsh-Weyl m-functions and Dirichlet-to-Neumann maps. A wide range of topics is considered in this context from the abstract to the applied, including boundary value problems for ordinary and partial differential equations; infinite-dimensional perturbations; local point-interactions; boundary and passive control state/signal systems; extension theory of accretive, sectorial and symmetric operators; and Calkin's abstract boundary conditions. This accessible treatment of recent developments, written by leading researchers, will appeal to a broad range of researchers, students and professionals.