Weak spectral equivalence and weak spectral convergence
Weighted shift operators on lp spaces.
The analytic-spectral structure of the commutant of a weighted shift operator defined on a lp space (1 ≤ p < ∞) is studied. The cases unilateral, bilateral and quasinilpotent are treated. We apply the results to study certain questions related to unicellularity, strictly cyclicity and the existence of hyperinvariant subspaces.