Weighted inequalities for commutators of fractional and singular integrals.
Weyl's and Browder's theorem for an elementary operator
Weyl's Theorem for a Generalized Derivation and an Elementary Operator
Where to find the image of a derivation
With this paper, we intend to provide an overview of some recent work on a problem on unbounded derivations of Banach algebras that still defies solution, the non-commutative Singer-Wermer conjecture. In particular, we discuss several global as well as local properties of derivations entailing quasinilpotency in the image.