title:  
A Crandall-Liggett approach to Gradient Flows in Metric Spaces


abstract:  

Motivated by applications to evolution equations in spaces of probability measures, 
Ambrosio, Gigli and Savare' introduced in their recent book an extension to complete metric spaces of the classical
theory of gradient flows in Hilbert spaces. The aim of this lecture is to present an alternative proof of the existence part of their theory.
It will be shown that the Crandall-Liggett approach to nonlinear semigroups can be carried over to this situation.