Hochschild cohomology of noncommutative planes and quadrics

Abstract

We give a description of the Hochschild cohomology for noncommutative planes (resp. quadrics) using the automorphism groups of the elliptic triples (resp. quadruples) that classify the Artin–Schelter regular $\mathbb{Z}$-algebras used to define noncommutative planes and quadrics. For elliptic triples the description of these automorphism groups is due to Bondal–Polishchuk, for elliptic quadruples it is new.