Atiyah-Bott fixed-point theorem 2026-11-05
The Atiyah-Bott fixed-point theorem computes an alternating trace on the cohomology of an elliptic complex from local data at fixed points. In the isolated, nondegenerate case, let be a smooth map of a closed smooth manifold, with compatible lifts commuting with the complex's differential operators. If at every fixed point, thenThe lifts, not just the map of the base, determine the action.[ref]
A Lefschetz Fixed Point Formula for Elliptic Complexes: I by M. F. Atiyah and R. Bott. Introduction, isolated fixed-point formula
For the de Rham complex and reflection of a circle, there are two fixed points with derivative . At each, the alternating fibre trace is and the denominator is two, giving local contribution one. Globally the induced actions on and are and , so both sides equal two. The holomorphic Lefschetz fixed-point formula applies the same idea to holomorphic complexes.