Quantum groups of Borcherds-Cartan type and Khovanov-Lauda-Rouquier algebras
Stefano V. Kang, Young Rock Kim, Bolun Tong
TL;DR
The paper develops a framework for quantum groups of Borcherds-Cartan type arising from quivers with loops and provides a categorification via Khovanov-Lauda-Rouquier algebras $R$. It proves that the indecomposable projective modules over $R$ correspond to Lusztig’s canonical basis of $U^-$, and in the Jordan quiver case shows that cyclotomic KLR algebras $R^ ext{\Lambda}$ categorify the irreducible highest-weight module $V(\Lambda)$. The authors connect the algebraic structure to a geometric realization using Steinberg-type algebras and Springer theory, establishing an isomorphism $_{\mathcal{A}}U^- \cong K_0(R)$ and identifying canonical bases with self-dual indecomposable projectives. In the Jordan case they further relate $K_0(R)$ to Specht modules and Schur functions, confirming the Springer correspondence yields a concrete categorification of highest-weight representations, including the cyclotomic cases. Overall, the work extends KLR categorification to quivers with loops, providing both algebraic and geometric perspectives and highlighting the Jordan quiver as a tractable, illuminating example of the general theory.
Abstract
We study a class of quantum groups $U^-$ associated with quivers with loops and provide a categorification by constructing their associated Khovanov-Lauda-Rouquier algebras $R$. We prove that the indecomposable projective module over $R$ corresponds to the canonical basis of $U^-$. In the Jordan quiver case, we show that the cyclotomic Khovanov-Lauda-Rouquier algebras $R^Λ$ categorify the irreducible highest weight $U$-module $V(Λ)$.
