The Metric Geometry of the Manifold of Riemannian Metrics over a Closed Manifold

Brian Clarke

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Submission date: 07. Apr. 2009
Pages: 15
published in: Calculus of variations and partial differential equations, 39 (2010) 3/4, p. 533-545 
DOI number (of the published article): 10.1007/s00526-010-0323-5
Bibtex
MSC-Numbers: 58D17, 58B20
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Abstract:
We prove that the Riemannian metric on the manifold of all smooth Riemannian metrics on a fixed closed, finite-dimensional manifold induces a metric space structure. As the metric is a weak Riemannian metric, this fact does not follow from general results. In addition, we prove several results on the exponential mapping and distance function of a weak Riemannian metric on a Hilbert/Frechet manifold. The statements are analogous to, but weaker than, what is known in the case of a Riemannian metric on a finite-dimensional manifold or a strong Riemannian metric on a Hilbert manifold.