The highest weight theory for Representations of General Linear groups in the Verlinde categories in positive characteristic
Alexandra Utiralova
TL;DR
This work extends representation theory in Verlinde categories Ver_p by building a comprehensive highest weight framework for GL(X) across varying Borels. It reduces the problem to GL(L_m⊕L_n) via odd reflections, then leverages a categorical $\widehat{\mathfrak{sl}}_p$-action from translation functors to realize loop-module structures and classify simple objects. It proves that Rep_{Ver_p}(GL(X)) carries a highest weight category structure with generalized Verma modules as standards, and establishes level-rank dualities and a Shapovalov-type criterion governing irreducibility of Kac modules in the super-analytic setting $GL(L_m|L_n)$. The results provide concrete combinatorics via weight diagrams and connect to classical supergroup theory, yielding a robust framework for translating highest weights across Borels and understanding projectives, reciprocity, and lowest weights in Ver_p.
Abstract
Following the work of Venkatesh (arXiv:2203.03158), we study further the categories of representations of the general linear groups $GL(X)$ in the Verlinde category $Ver_p$ in characteristic $p$. The main question we answer is how to translate between highest weight labelings for different choices of the Borel subgroup $B(X)\subset GL(X)$. We do this by reducing the general case to the study of representations of the group $GL(X)$ for $X=L_m\oplus L_{n}$ using the method of odd reflections. On the category of representations of $GL(L_m\oplus L_{n})$ we introduce the structure of the highest weight category, as well as the categorical action of $\widehat{\mathfrak{sl}}_p$ through translation functors. It allows us to understand projective and injective objects, BGG reciprocity, duality and lowest weights for simple modules, and standard filtration multiplicities for projective objects.
