Research group:
New Results in Hopf-cyclic Cohomology
21 – 24 May, 2011, Warsaw
Organizer
P.M. Hajac
Programme
Monday, 23rd of May
10.15, room 322
CYCLIC STRUCTURES IN ALGEBRAIC (CO)HOMOLOGY THEORIES
The cyclic cohomology of a left Hopf algebroid with coefficients in a right module left comodule is defined using a straightforward generalisation of the original operators given by Connes and Moscovici for Hopf algebras. A form of cyclic duality that makes sense for arbitrary para-cyclic objects yields a dual homology theory. The twisted cyclic homology of an associative algebra provides an example of this dual theory that uses coefficients that are not necessarily stable anti-Yetter-Drinfeld modules. (Joint work with N. Kowalzig.)
ULRICH KRAEHMER (University of Glasgow, Scotland)
Monday, 23rd of May 2011
14.15, room 322
CUP PRODUCTS IN HOPF-CYCLIC COHOMOLOGY WITH COEFFICIENTS IN CONTRAMODULES
We use stable anti-Yetter-Drinfeld contramodules as coefficients of Hopf-cyclic cohomology to achieve the functoriality of cup products. This generalization of original cup products in Hopf-cyclic cohomology allows us to define them for two different stable anti-Yetter-Drinfeld modules. To show that the choice of coefficients is important, we prove the non-trivial dependence of cup products on coefficients.
BAHRAM RANGIPOUR (University of New Brunswick, Fredericton, Canada)
Participants
- P.M. Hajac (IM PAN, Warsaw, Poland)
- U. Kraehmer (Glasgow, Scotland)
- T. Maszczyk (Warsaw, Poland)
- B. Rangipour (Fredericton, Canada)