Gerstenhaber type structures on Davydov-Yetter cohomology with coefficients

Abstract

We obtain Gerstenhaber type structures on Davydov-Yetter cohomology with coefficients in half-braidings for a monoidal functor. Our approach uses a formal analogy between half-braidings of a monoidal functor and the entwining of a coalgebra with an algebra. We show that the Davydov-Yetter complex with coefficients carries the structure of a weak comp algebra. In particular, it is equipped with two distinct cup product structures $\cup$ and $\sqcup$ which are related in a manner that replaces graded commutativity. We also introduce a subcomplex of the Davydov-Yetter complex with coefficients whose cohomology forms a Gerstenhaber algebra in the usual sense.