Abstract
In this paper we study subinjectivity domains of various R-modules and inclusion relations between these domains. We show that if the class of all subinjectivity domains is linearly ordered, then R is right Noetherian, and is either a right V-ring or a ring with unique noninjective simple module U. For the latter case, if U is projective but not indigent, then there exists a ring decomposition such that S is a semisimple Artinian ring and T is an indecomposable right Artinian right hereditary ring. Also, in that case, if the subinjectivity domain of U is the only middle subinjectivity domain, then R is right Artinian.
Acknowledgments
The second author expresses her sincere thanks to TÜBİTAK-BİDEP for her PhD scholarship award. All authors would like to thank the referee for the valuable comments and suggestions in shaping the article into its present form.
Disclosure statement
The authors declare that they have no conflicts of interest.