28 October 2026 — Padova

Representation theory of quantum affine algebras via tensor products of modules over hereditary algebras

Élie Casbi, University of Vienna

Abstract

We introduce new families of monoidal structures suited to categorifying important invariants arising in the representation theory of quantum affine algebras and in the theory of cluster algebras. Our framework builds on Auslander–Reiten theory and higher homological algebra; namely, for each finite acyclic quiver \(Q\), we construct a monoidal category \(\mathcal{R}_Q\) whose indecomposable objects are tensor products of modules over the path algebra of \(Q\). We show that to each indecomposable object \(X\) in \(\mathcal{R}_Q\) corresponds a (unique up to homotopy) chain complex \(C_\bullet(X)\) satisfying remarkable homological properties. These complexes are constructed using some iterated mapping cone procedure, which yields a collection of distinguished triangles in the bounded homotopy category of \(\mathcal{R}_Q\). We then prove that in the case where \(Q\) is a Dynkin quiver, the Euler characteristics of (the image under a suitable functor of) \(C_\bullet(X)\) be identified with the (truncated) \(q\)-character of a standard module over the quantum affine algebra \(U_q(\widehat{\mathfrak{g}_Q}).\) We also show that the above mentioned distinguished triangles categorify certain exchange relations in the finite type cluster algebra \(\mathcal{A}_Q\). If time allows, we will discuss perspectives towards monoidal categorifications of more general cluster structures.