Restriction of projective group representations to subgroups and centralizers. (English) Zbl 0785.20009

Nauwelaerts, E.; Delvaux, L.

J. Algebra 157, No. 1, 63-79 (1993).

From the introduction: “Projective representations of a group are homomorphisms into projective linear groups. In this paper we relate projective representations of a finite group \(G\) over a connected commutative ring \(R\) to projective representations of an arbitrary subgroup \(H\) of \(G\) (not necessarily normal in \(G\)). Obviously projective representations of \(G\) over \(R\) correspond to modules over twisted group rings \(R*_ \alpha G\), \(\alpha\) being a 2-cocycle. We concentrate on the separable case, that is, \(| G|^{-1}\in R\)”.

Reviewer: G.Karpilovsky (Chico)

MSC:

20C25

Projective representations and multipliers

Keywords:

projective representations; twisted group rings