We prove new spectral enclosures for the non-real spectrum of a class of 2 × 2 block operator matrices with self-adjoint operators A and D on the diagonal and operators B and − B* as off-diagonal entries. One of our main results resembles Gershgorin's circle theorem. The enclosures are applied to J-frame operators.
Información general
Fecha de publicación:2020
Idioma del documento:Inglés
Revista:Journal of Functional Analysis; vol. 278, no. 10
Institución de origen:Facultad de Ciencias Exactas