Character of Irreducible Representations Restricted to Finite Order Elements -- An Asymptotic Formula

Abstract

Let $G$ be a connected reductive group over the complex numbers and let $T\subset G$ be a maximal torus. For any $t\in T$ of finite order and any irreducible representation $V(\lambda)$ of $G$ of highest weight $\lambda$, we determine the character $ch(t, V(\lambda))$ by using the Lefschetz Trace Formula due to Atiyah-Singer and explicitly determining the connected components and their normal bundles of the fixed point subvariety $(G/P)^t\subset G/P$ (for any parabolic subgroup $P$). This together with Wirtinger's theorem gives an asymptotic formula for $ch(t, V(n\lambda))$ when $n$ goes to infinity.