“…In the context of operator algebras, some of the most well known preserving problems deal with characterizing linear maps on the algebra of all bounded linear operators acting on a Banach space which preserve Fredholm, semi-Fredholm or generalized invertible operators. New contributions to the study of linear preserver problems in L(H), the algebra of all bounded linear operators on an infinite dimensional complex Hilbert space H, have been recently made by several authors, see [3,4,5,12,13,14]. In [11], Kim and Park investigated linear maps φ on a unital C * -algebra A of real rank zero that are surjective up to some fixed closed ideal I and π(a) is invertible in A/I if and only if π(φ(A)) is invertible in A/I, where π : A → A/I is the canonical quotient map.…”