Monoidal categorification on open Richardson varieties
Yingjin Bi
TL;DR
The paper proves that in Dynkin types with v ≤ w, the subcategory \\mathscr{C}_{w,v} of modules over quiver Hecke algebras provides a monoidal categorification of the coordinate ring \\mathbb{C}[\\mathcal{R}_{w,v}] after inverting frozen cluster variables. It achieves this by employing Lusztig parameterizations to identify simple objects, constructing an initial monoidal seed from mutations of seeds in A_q(N(w)), and showing that cluster monomials correspond to simple objects in \\mathscr{C}_{w,v}. The approach unifies the preprojective- and KLR-algebra perspectives, linking determinantal modules to unipotent and Richardson-variety coordinates and leveraging delta-/\\Lusztig data to control mutations. This work extends known categorifications of unipotent coordinate rings to open Richardson varieties, enabling a representation-theoretic realization of their (quantum) cluster structures with potential impacts on geometric representation theory and algebraic combinatorics.
Abstract
In this paper, we show that the subcategory $\mathscr{C}_{w,v}$ of modules over quiver Hecke algebras is a monoidal categorification of the coordinate ring of any open Richardson variety of Dynkin types after inverting the frozen cluster variables.
