Bochner's theorem (Riemannian geometry)
Isometry group of a compact Riemannian manifold with negative Ricci curvature is finite / From Wikipedia, the free encyclopedia
In mathematics, Salomon Bochner proved in 1946 that any Killing vector field of a compact Riemannian manifold with negative Ricci curvature must be zero. Consequently the isometry group of the manifold must be finite.[1][2][3]