The coradical filtration for drinfeld double Ringel-Hall algebras

摘要

Let D(Lambda) be the Drinfeld double Ringel-Hall algebra with Lambda being any finite dimensional hereditary algebra over a finite field k. We determine the coradical filtration for D(Lambda). As an application, we describe the group of Hopf algebra automorphisms of the Drinfeld double Ringel composition algebra of Lambda. [References: 23]