Boundary rigidity and stability for generic simple metrics

We study the boundary rigidity problem for compact Riemannian manifolds with boundary (M, g) (M, g): is the Riemannian metric g g uniquely determined, up to an action of diffeomorphism fixing the boundary, by the distance function ρ g (x, y) g (x, y) known for all boundary points x x and y y? We prove in this paper local and global uniqueness and stability for the boundary rigidity problem for generic simple metrics. More specifically, we show that there exists a generic set G G of simple Riemannian metrics such that for any g 0 ∈ G g₀ G, any two Riemannian metrics in some neighborhood of g 0 g₀ having the same distance function, must be isometric. Similarly, there is a generic set of pairs of simple metrics with the same property. We also prove Hölder type stability estimates for this problem for metrics which are close to a given one in G G.