In this paper, we study rings having the property that every finitely generated right ideal is
automorphism-invariant. Such rings are called right f a-rings. It is shown that a right f a-ring …

The notion of a nilpotent-invariant module was introduced and thoroughly investigated in
Koşan and Quynh (Comm. Algebra 45, 2775–2782) as a proper extension of an …

In this paper, by taking the class of all C 3 (or D 3) right R-modules for general envelopes
and covers, we characterize a semisimple artinian ring (or a right perfect ring) via D 3-covers …

Throughout this paper, all rings R are associative with identity and all modules are unitary
right R-module. The notations N≤ e M and N≤⊕ M mean that N is an essential submodule …

A module is called nilpotent-coinvariant if it is invariant under any nilpotent endomorphism of
its projective cover. Some properties of this class of these modules were investigated by …

It is shown that every nilpotent-invariant module can be decomposed into a direct sum of a
quasi-injective module and a square-free module that are relatively injective and orthogonal …

In this paper, we firstly provide several new characterizations of quasi-Frobenius rings by
using some generalized injectivity of rings with certain chain conditions. For example,(1) a …