Virtual Seminar Talk at Washington University in St Louis
Channel: Maria Gillespie
Date: 2022-06-15

Title: 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.