Optimal transportation between densities f(X), g(Y) can be interpreted as a
joint probability distribution with marginally f(X), and g(Y). We prove mo
notonicity and concavity properties of optimal transportation (Y(X)) under
suitable assumptions on f and g. As an :application we obtain the Fortuin,
Kasteleyn, Ginibre correlation inequalities as well as some generalization
of the Brascamp-Lieb momentum inequalities.