Since long over the decades there has been a large transversal community of mathematicians grappling with the sophisticated challenges of the rigorous modelling

This book presents a thorough discussion of the theory of abstract inverse linear problems on Hilbert space. Given an unknown vector f in a Hilbert space H, a l

This volume is dedicated to the memory of Sergey Naboko (1950-2020). In addition to original research contributions covering the vast areas of interest of Serge

This book introduces and discusses the self-adjoint extension problem for symmetric operators on Hilbert space. It presents the classical von Neumann and Krein�

This book provides a valuable collection of contributions by distinguished scholars presenting the state of the art and some of the most significant latest deve