Kontsevich’s theorem and Morita’s cycles


Morita’s cycles are an infinite sequence of cycles in the unstable homology of \mbox{Out}(F_n). Their construction is motivated by a remarkable theorem of Kontsevich which relates these homology groups with the cohomology of a certain Lie algebra \mathfrak{h}_\infty associated to the Lie operad.

I will define operads, giving plenty of examples, and introduce the unstable range of H_\ast(\mbox{Out}(F_n)), showing where these Morita cycles fit in. I’ll then state Kontsevich’s theorem and explain how Mortia’s observation leads to cycles in the homology of \mbox{Out}(F_n).


Slides as a (large) PDF
Slides as a keynote

\leftarrow Back to talks and papers