NULL-ORBIT REFLEXIVE OPERATORS

作者：Hadwin Don^*; Ionascu Ileana; Yousefi Hassan

来源：Operators and Matrices, 2012, 6(3): 567-576.

DOI：10.7153/oam-06-38

• Operators
• subspaces
• null-orbit reflexivity

We introduce and study the notion of null-orbit reflexivity, which is a slight perturbation of the notion of orbit-reflexivity. Positive results for orbit reflexivity and the recent notion of C-orbit reflexivity both extend to null-orbit reflexivity. Of the two known examples of operators that are not orbit-reflexive, one is null-orbit reflexive and the other is not. The class of null-orbit reflexive operators includes the classes of hyponormal, algebraic, compact, strictly block-upper (lower) triangular operators, and operators whose spectral radius is not I. We also prove that every polynomially bounded operator on a Hilbert space is both orbit-reflexive and null-orbit reflexive.

• 出版日期2012-9