We introduce the notion of a t-nilpotent endomorphism of modules and study the modules
which are invariant under t-nilpotent endomorphisms of their injective envelope, such as …

We introduce and investigate t-idempotent invariant modules. We call an endomorphism ψ
of M, at-idempotent endomorphism if ψ ̄: M/Z 2 (M)→ M/Z 2 (M) defined by ψ ̄ (m+ Z 2 …

The purpose of this paper is to study the structure of rings over which every essential
extension of a direct sum of a family of simple modules is a direct sum of automorphism …