Pseudotropical curves

Abstract

We propose a generalization of tropical curves by dropping the rationality and integrality requirements while preserving the balancing condition. An interpretation of such curves as critical points of a certain quadratic functional allows us to settle the existence and uniqueness problem. The machinery of dual polygons and the intersection theory also generalize as expected. We study the homology of a compactified moduli space of rigid oriented marked curves. A weighted count of rational pseudotropical curves passing through a generic collection of points is interpreted via top-degree cycles on the moduli. We construct a family of such cycles using quantum tori Lie algebras and show that in the usual tropical case this gives the refined curve count of Block and Göttsche. Finally, we derive a recursive formula for this Lie-weighted count of rational pseudotropical curves.