This book introduces and discusses the self-adjoint extension problem for symmetric operators on Hilbert space. It presents the classical von Neumann and Krein–Vishik–Birman extension schemes both in their modern form and from a historical perspective, and provides a detailed analysis of a range of applications beyond the standard pedagogical examples (the latter are indexed in a final appendix for the reader’s convenience).Self-adjointness of operators on Hilbert space representin...

This present book collects a distinguished selection of contributions by scholars who participated as speakers or as visiting scientists in the intensive programme Puglia Summer Trimester 2023 took place in Bari, Italy, from April to July 2023, and also includes contributions by further scholars who are expert in related fields. The programme was structured around a series of main meetings, including a general conference and a summer school, supplemented by the local presence and activitie...