Research in Hilbert space operators and Berezin numbers constitutes a fertile arena in modern mathematical analysis, bridging abstract operator theory with practical applications in spectral theory ...

Hilbert space theory and operator algebras provide a robust framework for analysing linear operators and their spectral properties, which are pivotal in both pure and applied mathematics. Hilbert ...

Two weeks ago, a modest-looking paper was uploaded to the arXiv preprint server with the unassuming title “On the invariant subspace problem in Hilbert spaces”. The paper is just 13 pages long and its ...

In this paper, a sufficient condition for the existence of hyperinvariant subspace of compact perturbations of multiplication operators on some Banach spaces is presented. An interpretation of this ...