Quiver moduli and quantum loop algebras
Andrei Neguţ
TL;DR
The paper develops a comprehensive geometric and K-theoretic realization of simple modules in the Borel category O for quantum loop algebras U_q(L{\mathfrak{g}}), extending known HL-type Euler-characteristic connections from reachable to all highest ell-weights {\boldsymbol{\psi}}. It constructs and analyzes shuffle algebra models (big and small) to describe q-characters, and couples them with framed moduli of quiver representations and their critical K-theory. The central result is a categorification: coefficients of χ_q(L^{≠0}({\boldsymbol{\psi}})) correspond to dimensions of spaces from 𝒮_{\boldsymbol{n}}/(𝒮_{\boldsymbol{n}} ∩ Θ(\boldsymbol{ψ})_{\boldsymbol{x}}), realized geometrically via framed stable critical K-theory of quivers with potential; for strongly symmetrizable {\mathfrak{g}}, this yields an explicit, geometry-driven construction of all simple modules in Borel U_q(L{\mathfrak{g}}) and their q-characters. The approach integrates shuffle algebra techniques, quiver moduli, and critical K-theory (with stable envelopes) to generalize HL results, providing a robust framework with potential extensions to quantum toroidal algebras. This advances understanding of the interface between representation theory, algebraic geometry, and mathematical physics, offering concrete computational tools through K-theoretic and combinatorial structures.
Abstract
A classic result of Hernandez-Leclerc and Kashiwara-Kim-Oh-Park relates the q-characters of so-called reachable simple modules of quantum affine algebras to the Euler characteristics of certain quiver moduli spaces. We categorify and generalize this relation to all simple modules in the Hernandez-Jimbo category O using critical K-theory (our results hold for quantum toroidal as well as quantum affine algebras)
