Associative algebra deformations of the Connes-Moscovici's Hopf algebra ${\mathcal{H}}_1$

Alice Fialowski, Friedrich Wagemann

We compute the second Hochschild cohomology space $H{H}^2({\mathcal{H}}_1)$ of Connes-Moscovici's Hopf algebra ${\mathcal{H}}_1$, giving the infinitesimal deformations (up to equivalence…