Functional inequalities and Hamilton-Jacobi Equations in Geodesic Spaces
arXiv:0906.0476
Abstract
We study the connection between the --Talagrand inequality and the --logarithmic Sololev inequality for conjugate exponents , in proper geodesic metric spaces. By means of a general Hamilton--Jacobi semigroup we prove that these are equivalent, and moreover equivalent to the hypercontractivity of the Hamilton--Jacobi semigroup. Our results generalize those of Lott and Villani. They can be applied to deduce the -Talagrand inequality in the sub-Riemannian setting of the Heisenberg group.
21 pages