Shlomo Gelaki – Lunes 7 de diciembre – 14:00hs

Resumen: The theory of twisting deformations of a Hopf algebra H goes back to Drinfeld and was extensively studied by Etingof-Kazhdan, Movshev, Etingof-Gelaki, and others. Namely, a Hopf 2-cocycle J in (H\otimes H)^* gives rise to a new Hopf algebra J_H_J such that the tensor corepresentation categories of H and J_H_J are equivalent.
 In my talk I will first discuss the classification of Hopf 2-cocycles J in (O(G)\otimes O(G))^*, where O(G) is the coordinate algebra of a connected nilpotent algebraic group G over C, and then present some general results about the algebra structure and representation theory of the twisted cotriangular Hopf algebra J_O(G)_J and the twisted algebra O(G)_J.