Differential Forms on Wasserstein Space and Infinite-Dimensional Hamiltonian Systems

Download or read book Differential Forms on Wasserstein Space and Infinite-Dimensional Hamiltonian Systems written by Wilfrid Gangbo and published by American Mathematical Soc.. This book was released on 2010 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Let $\mathcal{M}$ denote the space of probability measures on $\mathbb{R}^D$ endowed with the Wasserstein metric. A differential calculus for a certain class of absolutely continuous curves in $\mathcal{M}$ was introduced by Ambrosio, Gigli, and Savare. In this paper the authors develop a calculus for the corresponding class of differential forms on $\mathcal{M}$. In particular they prove an analogue of Green's theorem for 1-forms and show that the corresponding first cohomology group, in the sense of de Rham, vanishes. For $D=2d$ the authors then define a symplectic distribution on $\mathcal{M}$ in terms of this calculus, thus obtaining a rigorous framework for the notion of Hamiltonian systems as introduced by Ambrosio and Gangbo. Throughout the paper the authors emphasize the geometric viewpoint and the role played by certain diffeomorphism groups of $\mathbb{R}^D$.