Three Cocycles on $\Diff(S^1)$ Generalizing the Schwarzian Derivative

S. Bouarroudj, V. Ovsienko

The first group of differentiable cohomology of $\Diff(S^1)$, vanishing on the Möbius subgroup $PSL(2,R)\subset\Diff(S^1)$, with coefficients in modules of linear differential oper…