Tim: in your blog article, you wrote:

> We will take as a model of the domain of the fluid flow a compact Riemannian manifold $M$ that is also a Lie group.

I really don't think we need $M$ to be a Lie group. What we need is for the diffomorphism group $\mathrm{Diff}(M)$ to be an infinite-dimensional Lie group - and it always will be if $M$ is a compact Riemannian manifold. So I'm going to delete that last bit.

I'm also going to change your $D M$ to $\mathrm{Diff}(M)$ because the latter is standard and you have another very important thing called $D$ in this blog entry!