The reduced minimum modulus of Drazin inverses of linear operators on Hilbert spaces
Chunyuan Deng, Hong-Ke Du · Proceedings of the American Mathematical Society · 2006
In this article, we study the reduced minimum modulus of the Drazin inverse of an operator on a Hilbert space and give lower and upper bounds of the reduced minimum modulus of an operator and its Drazin inverse, respectively. Using these results, we obtain a characterization of the continuity of Drazin inverses of operators on a Hilbert space.