Hochschild cohomology for a class of some self-injective special biserial algebras of rank four

Abstract

In this paper, we construct an explicit minimal projective bimodule resolution of a self-injective special biserial algebra $A_{T}$ ($T\geq0$) whose Grothendieck group is of rank $4$. As a main result, we determine the dimension of the Hochschild cohomology group ${\rm HH}^{i}(A_{T})$ of $A_{T}$ for $i\geq0$, completely. Moreover we give a presentation of the Hochschild cohomology ring modulo nilpotence ${\rm HH}^{*}(A_{T})/\mathcal{N}_{A_{T}}$ of $A_{T}$ by generators and relations in the case where $T=0$.