Hochschild Cohomology of Polynomial Representations of $\mathrm{GL}_2$
Hochschild Cohomology of Polynomial Representations of $\mathrm{GL}_2$
We compute the Hochschild cohomology algebras of Ringel-self-dual blocks of polynomial representations of \mathrm{GL}_2 over an algebraically closed field of characteristic p>2 , that is, of any block whose number of simple modules is a power of p . These algebras are finite-dimensional and we provide an explicit description of …