The Stable Picard Group of A(n)

Abstract

In this paper, we showed that the Stable Picard group of $A(n)$ for $n\ge 2$ is $\mathbb{Z}\oplus \mathbb{Z}$ by considering the endotrivial modules over $A(n)$. The proof relies on reductions from a Hopf algebra to its proper Hopf subalgebras.

20 pages