Proceedings of the American Mathematical Society, Vol. 131, No. 5 (May, 2003), pp. 1539-1551 (13 pages) This paper provides a variety of sufficient conditions for the existence of a nonzero fixed ...

Hilbert space theory and operator algebras provide a robust framework for analysing linear operators and their spectral properties, which are pivotal in both pure and applied mathematics. Hilbert ...

In this paper, the reverse order law of Drazin inverse is investigated under some conditions in a Banach space. Moreover, the Drazin invertibility of sum for two bounded linear operators are also ...