On extensions of principal series representations

Gautam H. Borisagar, Asfak Soneji

We compute ${\mathrm{Ext}}_B^1({\chi }_1,{\chi }_2)$ between two characters ${\chi }_1,{\chi }_2$ of a Borel subgroup $B$ of a split reductive group $G$ over a finite field ${\mathbb{F}}_q,$ and make an app…