Rank equalities related to a class of outer generalized inverse

Abstract

[EN] In 2012, Drazin introduced a class of outer generalized inverse in a ring R, the (b, c)-inverse of a for a,b,c is an element of R and denoted by a(parallel to(b,c)). In this paper, rank equalities of A(k)A(parallel to(B,C)) - A parallel to((B,C))A(k) and (A*)(k)A(parallel to(B,C) )-( )A(parallel to(B,C))(A*)(k )are obtained. As applications, we investigate equivalent conditions for the equalities (A*)(k)A(parallel to(B,C)) = A(parallel to(B,C))(A*)(k) and A(k)A(parallel to(B,C)) = A(parallel to(B,C))A(k). As corollaries we obtain rank equalities related to the Moore-Penrose inverse, the core inverse, and the Drazin inverse. The paper finishes with some rank equalities involving different expressions containing A(parallel to(B,C)).