This open access book presents a comprehensive survey of modern operator techniques for boundary value problems and spectral theory, employing abstract boundary

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 boun

This volume collects contributions from participants in the IWOTA conference held virtually at Lancaster, UK, originally scheduled in 2020 but postponed to Augu

Consists of the expository paper based on the 6-hour minicourse given by Professor Bert-Wolfgang Schulze, and sixteen papers based on lectures given at the work

- Detailed bibliographical comments and some open questions are given after each chapter - Indicates connections between the content of the book and many other