Abstract
In this paper, we study operators for which T*T and T + T* commute. Let Θ denote the class of such operators in L(H). We show that every operator in Θ is subscalar of order 4. From this result, we give partial solutions to the invariant subspace problem. In addition, we examine some extensions of operators in Θ. Finally, we prove that if T belongs to Θ, then Weyl's theorem holds for T and the spectral mapping theorem corresponding to the Weyl spectrum is satisfied for T.
Original language | English |
---|---|
Pages (from-to) | 849-860 |
Number of pages | 12 |
Journal | Bulletin of the London Mathematical Society |
Volume | 45 |
Issue number | 4 |
DOIs | |
State | Published - Aug 2013 |
Bibliographical note
Funding Information:This work was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) grant funded by the Korean government(MEST) (2012-0000939).