Automorphisms of residue rings of integer rings of circular fields

The authors research the structure of residue rings of integer rings of circular fields by analyzing their ring automorphisms. The connections between a special subgroup of the automorphism group and the system of the inserted subrings of the residue rings are found. Among the occurring subrings the authors found a very prospective one for further research as well as a multitude of its noninvertible elements for some nontrivial cases.