Determinantal modules over preprojective algebras and representations of Dynkin quivers

Abstract

In this paper, we study extension groups of determinantal modules over a preprojective algebra using the Auslander-Reiten translation of the quiver associated with it. More precisely, based on the recent work given by Aizenbud and Lapid, we calculate the extension group of a sort of so-called determinantal modules, which is an analog of quantum minors in quantum coordinate rings. In particular, we give an equivalent combinatorial condition when the product of two quantum minors (up to q-power rescaling) belongs to the dual canonical basis of quantum coordinate rings in the Dynkin case. More generally, we can check the quasi-commuting condition for any two quantum cluster monomials with the seeds of quantum minors.