Summary: Journal of Pure and Applied Algebra 210 (2007) 8191
On deformations of crossed products
Eli Aljadeffa,, Yuval Ginosarb, Andy R. Magidc
a Department of Mathematics, Technion-Israel Institute of Technology, Haifa 32000, Israel
b Department of Mathematics, University of Haifa, Haifa 31905, Israel
c Department of Mathematics, University of Oklahoma, Norman 73019, OK, USA
Received 12 October 2005; received in revised form 2 August 2006
Available online 5 October 2006
Communicated by C. Kassel
Let A be a crossed product algebra, where A is semisimple, finitely generated over its center and is a finite group. We
give a necessary and sufficient condition in terms of the outer action of on A for the existence of a multi-parametric semisimple
deformation of the form A((t1, . . . , tn)) (with the induced outer action). The main tool in the proof is the solution of the
so-called twisting problem. We also give an example which shows that the condition is not sufficient if one drops the condition on
the finite generation of A over its center.
c 2006 Elsevier B.V. All rights reserved.
Let R = A be a crossed product algebra, where A is an artinian ring, finitely generated over its center, and