On the Kleinecke–Shirokov Theorem for families of derivations
Studia Mathematica 149 (2002), 185-190 MSC: Primary 47B47. DOI: 10.4064/sm149-2-7
It is proved that Riesz elements in the intersection of the kernel and the closure of the image of a family of derivations on a Banach algebra are quasinilpotent. Some related results are obtained.