On subinjectivity domains of RD-injective modules

The subjectivity domain of a module allows us to evaluate how close (or far) a module is from being injective. In this paper, we consider three families of rings characterized by their RD-injective left R-modules via the subinjective domain: those whose noninjective RD-injective left R-modules are subinjective relatively only to divisible modules, those whose noninjective RD-injective left R-modules are subinjective relatively only to fp-injective modules and those whose noninjective RD-injective left R-modules are subinjective relatively only to injective modules.