Orthonormal Spectral Cluster Bounds on Manifolds with Nonpositive Curvature

Jean-Claude Cuenin, Ngoc Nhi Nguyen, Xiaoyan Su

Let $(M,g)$ be a closed $n$-dimensional Riemannian manifold with nonpositive sectional curvature. We prove sharp, logarithmically improved spectral cluster bounds for orthonormal s…