Automorphism Groups of Schur Rings

dc.creatorKerby, Brent
dc.date2009-05-12
dc.date.accessioned2026-07-07T13:14:08Z
dc.date.available2026-07-07T13:14:08Z
dc.descriptionIn 1993, Muzychuk \cite{muzychuk} showed that the rational Schur rings over a cyclic group $Z_n$ are in one-to-one correspondence with sublattices of the divisor lattice of $n$, or equivalently, with sublattices of the lattice of subgroups of $Z_n$. This can easily be extended to show that for any finite group $G$, sublattices of the lattice of characteristic subgroups of $G$ give rise to rational Schur rings over $G$ in a natural way. Our main result is that any finite group may be represented as the (algebraic) automorphism group of such a rational Schur ring over an abelian $p$-group, for any odd prime $p$. In contrast, we show that over a cyclic group the automorphism group of any Schur ring is abelian. We also prove a converse to the well-known result of Muzychuk \cite{muzychuk2} that two Schur rings over a cyclic group are isomorphic if and only if they coincide; namely, we show that over a group which is not cyclic, there always exist distinct isomorphic Schur rings.
dc.identifierhttps://arxiv.org/abs/0905.1898
dc.identifierhttp://arxiv.org/abs/0905.1898
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/230115
dc.subjectRings and Algebras
dc.subjectGroup Theory
dc.subject16S34
dc.titleAutomorphism Groups of Schur Rings
dc.typetext

Files

Collections