{"product_id":"9781139564939","title":"Operator Methods for Boundary Value Problems","description":"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.","brand":"Cambridge University Press","offers":[{"title":"Default Title","offer_id":47080214069488,"sku":"9781139564939","price":60.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0737\/7593\/9824\/files\/9781139564939_p0.jpg?v=1763699932","url":"https:\/\/shop-qa.barnesandnoble.com\/products\/9781139564939","provider":"Barnes \u0026 Noble (DEV)","version":"1.0","type":"link"}