Intersections of ω classes in Mg,ₙ

Original · EN

We provide a graph formula which describes an arbitrary monomial in ω classes (also referred to as stable ψ classes) in terms of a simple family of dual graphs (pinwheel graphs) with edges decorated by rational functions in ψ classes. We deduce some numerical consequences and in particular a combinatorial formula expressing top intersections of appa classes on Mg in terms of top intersections of ψ classes.