Let A = circle plus(infinity)(n=0)An be a connected graded k-algebra over an algebraically dosed field k (thus A(0) = k). Asstanie that a finite Abelian group G, of order cop rime to the characteristic of k, acts on A by graded automorphisms. In conjunction with a suitable cocycle, this action can be used to twist the multiplication in A. We study this new structure and, in particular, we describe when properties like Artin-Schelter regularity are preserved by such a twist. We then apply these results to examples of Rogalski and Zhang.
展开▼
