It is proved, among other results, that a prime right nonsingular ring (in particular, a simple
ring) R is right self-injective if RR is invariant under automorphisms of its injective hull. This …

Warfield proved that every injective module has the exchange property. This was
generalized by Fuchs who showed that quasi-injective modules satisfy the exchange …

Automorphism-invariant modules Page 30 Contemporary Mathematics Volume 634, 2015
http://dx. doi. org/10.1090/conm/634/12688 Automorphism-Invariant Modules Pedro A. Guil …

In this paper we develop a general theory of modules which are invariant under
automorphisms of their covers and envelopes. When applied to specific cases like injective …

A module M is called a D 4-module if, whenever A and B are submodules of M with M= A⊕
B and f: A→ B is a homomorphism with Im f⊆⊕ B, we have ker f⊆⊕ A. The class of D 4 …

A module is called automorphism-invariant if it is invariant under any automorphism of its
injective hull. In [Algebras for which every indecomposable right module is invariant in its …

We use the type theory for rings of operators due to Kaplansky to describe the structure of
modules that are invariant under automorphisms of their injective envelopes. Also, we …

In this paper we study modules coinvariant under automorphisms of their projective covers.
We first provide an alternative, and in fact, a more succinct and conceptual proof for the …

" The study of modules which are invariant under the action of certain subsets of the
endomorphism ring of their injective envelope can be drawn back to the pioneering work of …

A module is called automorphism-invariant if it is invariant under any automorphism of its
injective hull. Dickson and Fuller have shown that if R is a finite-dimensional algebra over a …