English

On extensions of principal series representations

Representation Theory 2026-02-10 v1

Abstract

We compute ExtB1(χ1,χ2)\mathrm{Ext}^{1}_B(\chi_1,\chi_2) between two characters χ1,χ2\chi_1,\chi_2 of a Borel subgroup BB of a split reductive group GG over a finite field Fq,\mathbb{F}_q, and make an application to the calculation of ExtG1(π1,π2)\mathrm{Ext}^1_G(\pi_1,\pi_2) between principal series representations π1,π2\pi_1,\pi_2 of G(Fq).G(\mathbb{F}_q).

Keywords

Cite

@article{arxiv.2501.04301,
  title  = {On extensions of principal series representations},
  author = {Gautam H. Borisagar and Asfak Soneji},
  journal= {arXiv preprint arXiv:2501.04301},
  year   = {2026}
}