On Matlis dualizing modules

Resumen

We consider rings admitting a Matlis dualizing module E . We argue that if R admits two such dualizing modules, then a module is reflexive with respect to one if and only if it is reflexive with respect to the other. Using this fact we argue that the number (whether finite or infinite) of distinct dualizing modules equals the number of distinct invertible ( R , R )‐bimodules. We show by example that this number can be greater than one.