English

Remarks on curvature in the transportation metric

Differential Geometry 2017-01-02 v3

Abstract

According to a classical result of E.~Calabi any hyperbolic affine hypersphere endowed with its natural Hessian metric has a non-positive Ricci tensor. The affine hyperspheres can be described as the level sets of solutions to the "hyperbolic" toric K\"ahler-Einstein equation eΦ=detD2Φe^{\Phi} = \det D^2 \Phi on proper convex cones. We prove a generalization of this theorem by showing that for every Φ\Phi solving this equation on a proper convex domain Ω\Omega the corresponding metric measure space (D2Φ,eΦdx)(D^2 \Phi, e^{\Phi}dx) has a non-positive Bakry-{\'E}mery tensor. Modifying the Calabi computations we obtain this result by applying the tensorial maximum principle to the weighted Laplacian of the Bakry-{\'E}mery tensor. Our computations are carried out in a generalized framework adapted to the optimal transportation problem for arbitrary target and source measures. For the optimal transportation of the log-concave probability measures we prove a third-order uniform dimension-free apriori estimate in the spirit of the second-order Caffarelli contraction theorem, which has numerous applications in probability theory.

Keywords

Cite

@article{arxiv.1604.04165,
  title  = {Remarks on curvature in the transportation metric},
  author = {Bo'az Klartag and Alexander Kolesnikov},
  journal= {arXiv preprint arXiv:1604.04165},
  year   = {2017}
}

Comments

18 pages; minor changes