Determinants of Laplacians as functions on spaces of metrics


Young-Heon Kim

University of Toronto

November 20, 2006


Abstract: The determinant of the Laplacian is a global Riemannian invariant which is defined formally as the product of all the infinitely many nonzero eigenvalues of the Laplacian of the given Riemannian metric. This determinant gives us a continuous function on the space of Riemannian metrics.  In this talk we are interested in the case of compact surfaces with boundary and will discuss the properness of the determinant function on the moduli space of hyperbolic surfaces with geodesic boundary. We will also discuss its application to the following isospectral compactness problem: On a given compact surface with boundary, consider the set of all smooth flat metrics having the same Dirichlet Laplacian spectrum, is it compact in C^\infty topology?

This talk has the same theme as the talk I have given in the Analysis/Applied Math/PDE seminar on Oct. 13., but this time we will focus more on the ideas of the proofs and the methods.