Title: Orbital integrals for gln and smoothening

Abstract: Orbital integral is a fundamental object in the geometric side of the trace formula. A traditional method to study orbital integrals is through Bruhat-Tits building or affine Springer fiber. In this talk, we will propose another method to study orbital integrals using smoothening.
As an application, we will explain a closed formula of the orbital integral for gln with n=2,3 and a new lower bound for a general n. We also propose a conjecture about the estimation of the orbital integral for any n. Our method works for any local field of characteristic 0 or >n. This is a joint work with Sungmun Cho.