Algebraic Geometry Seminar: "Multiplicity-free formulas for products of psi and omega classes on M_0,n-bar via degenerations"

Abstract: We provide a positive, multplicity-free formula for products of "psi" classes and products of "omega" classes on the moduli space M_{0,n}-bar of n-marked stable curves of genus 0, and express the formulas as a combinatorial sum of trees corresponding to boundary strata.  These trees are given by a combinatorial algorithm on trees we call "slide labeling".   Geometrically, our construction is built up inductively as a sequence of one-parameter degenerations, using an explicit parametrized collection of hyperplane sections. This is joint work with Sean Griffin and Jake Levinson.

Host: Ben Wormleighton