Counting plane curves with Psi-floor diagrams

Floor diagrams are combinatorial objects inspired by tropical geometry. They enumerate algebraic plane curves satisfying point and tangency conditions, thus providing a Littlewood-Richardson type rule for some intersection numbers on the moduli space of curves (or, rather, of stable maps). We extend the combinatorics of floor diagrams to allow curve counts with additional conditions given by ``Psi-classes'' (which are crucial in Gromov-Witten theory), and present a new correspondence theorem in tropical geometry.

This is joint work with Andreas Gathmann and Hannah Markwig.