Compactness of isospectral conformal metrics on 4-manifolds
arXiv:1911.13100
Abstract
Let a sequence of conformal Riemannian metrics be isospectral to over a compact boundaryless smooth 4-dimension manifold . We prove that the subsequence of conformal factors converges to weakly in for some , where is a finite set of points and . Moreover, if the isospectral invariant is strictly smaller than the Yamabe constant of the standard sphere , then the subsequence of distance functions defined by uniformly converges to and the subsequence of metric spaces converges to the metric space in the Gromov-Hausdorff topology, where is the distance function defined by .