Clebsch-Gordan and the theta filtration for modular representations of ${\mathrm{GL}}_2({\mathbb{F}}_q)$

Srijeet Bhattacharjee, Eknath Ghate, Shivansh Pandey +1

Let $p$ be a prime. We solve two problems in the mod $p$ representation theory of ${\mathrm{GL}}_2({\mathbb{F}}_q)$ where $q=p^f$. We first prove a Clebsch-Gordan decomposition theor…