Yannic Vargas (Univ. of Potsdam and IVIC, Caracas, Venezuela)
Pairs of cointeracting bialgebras recently appeared in the study of combinatorial Hopf algebras based on trees (Calaque, Ebrahimi-Fard, Manchon), graphs (Manchon) and posets (Foissy). Several results on pairs of cointeracting bialgebras were obtained with application to Ehrhart polynomials and chromatic polynomials, actions on the group of characters and the description of the antipode of a bialgebra in cointeraction. In this talk we will illustrate some of those properties on one new pair of cointeracting bialgebra based on set partitions and in a bialgebra in cointeraction based on permutations introduced by Schocker. This is joint work with Loïc Foissy.
Forthcoming speakers are John Barrett on May 21st, Malte Leimbach on May 28th, Alfonso Garmendia on June 4th, Konrad Waldorf on June 11th and Bernadette Lessel on July 2nd.
You are welcome to invite your friends and colleagues to join us! If you wish to attend the talks, please contact Sylvie Paycha paycha@math.uni-potsdam.de for the login details.