Verma Howe duality and LKB representations
Abel Lacabanne, Daniel Tubbenhauer, Pedro Vaz
TL;DR
The paper introduces Verma Howe duality, replacing symmetric powers with Verma modules and establishing a commuting-action framework between $U_q(rak{gl}_2)$ and $U_q(rak{gl}_n)$. It constructs dense, non-highest/lowest weight multiplicity spaces and, via a GT-pattern/Casimir analysis and flatness arguments, lifts the duality to the quantum setting. As a key application, colored higher LKB representations arise from this duality and are proven to be simple modules for braid groups and relevant subgroups, including the pure braid group, over general fields and parameters. The results broaden Howe duality to infinite-dimensional, nonsemisimple contexts and pave the way for further categorification and connections to handlebody braids and symmetric web calculi.
Abstract
We establish a version of Howe duality that involves a tensor product of Verma modules. Surprisingly, this duality leaves the realm of lowest and highest weight modules. We quantize this duality, and as an application, we prove that the (colored higher) LKB representations arise from this duality and use this description to show that they are simple as modules for the braid group and for various of its subgroups, including the pure braid group.
