ISBN-13: 9783319688480 / Angielski / Twarda / 2018 / 495 str.
ISBN-13: 9783319688480 / Angielski / Twarda / 2018 / 495 str.
In particular, he studied the domains of operator pencils and nonlinear eigenvalue problems, the theory of indefinite inner product spaces, operator theory in Pontryagin and Krein spaces, and applications to mathematical physics.