This preprint was accepted August 2000
Contact:
S.Evdokimov and I.Ponomarenko
ABSTRACT: We disprove the following long-time hypothesis: any Schur ring over a finite cyclic group is determined by a suitable permutation group having this cyclic group as a regular subgroup. In addition, we give a negative solution to the problem whether any weak isomorphism of Schur rings over a finite cyclic group is induced by a strong isomorphism.[ Full text: (.ps.gz)]