The University of Michigan Combinatorics Seminar
Winter 2010
April 2, 4:10-5:00, 3866 East Hall

Counting plane curves with Psi-floor diagrams

Florian Block

University of Michigan


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.