Prékopa–Leindler type inequalities on Riemannian manifolds, Jacobi fields, and optimal transport

Abstract

We investigate Prékopa-Leindler type inequalities on a Riemannian manifold M equipped with a measure with density e - V where the potential V and the Ricci curvature satisfy Hess x V + Ric x ≥ λ I for all x ∈ M , with some λ ∈ ℝ . As in our earlier work [14], the argument uses optimal mass transport on M , but here, with a special emphasis on its connection with Jacobi fields. A key role will be played by the differential equation satisfied by the determinant of a matrix of Jacobi fields. We also present applications of the method to logarithmic Sobolev inequalities (the Bakry-Emery criterion will be recovered) and to transport inequalities. A study of the displacement convexity of the entropy functional completes the exposition.