In this talk we present recent results on the asymptotic growth of eigenvalues of the Laplace-Beltrami operator on singular Riemannian manifolds, where all geometrical invariants appearing in classical spectral asymptotics are unbounded, and the total volume can be infinite. Under suitable assumptions, we prove that the leading term of the Weyl’s asymptotics contains information on the singularity, i.e. its Minkowski dimension and its regularized measure. We apply our results to a suitable class of almost-Riemannian structures. A key tool in the proof is a new heat trace estimate with universal remainder for Riemannian manifolds, which is of independent interest.
This is a joint work with Y. Chitour and L. Rizzi.