Moduli space actions and cyclic operads

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Ben Ward , Simons Center, Stony Brook
Fine Hall 214

Please note different location.   I will describe a combinatorial dg model for the homology of the open moduli spaces of punctured Riemann spheres. This model acts (in the operadic sense) on chain complexes computing eg string topology, cyclic cohomology of a Frobenius algebra, or equivariant cohomology of an S^1 space.  We thus find homology operations old and new, as well as a homotopy invariant description of the chain level structures which produce these operations.