English

Realizability of tropical canonical divisors

Algebraic Geometry 2017-11-29 v2 Geometric Topology

Abstract

We use recent results by Bainbridge-Chen-Gendron-Grushevsky-Moeller on compactifications of strata of abelian differentials to give a comprehensive solution to the realizability problem for effective tropical canonical divisors in equicharacteristic zero. Given a pair (Γ,D)(\Gamma, D) consisting of a stable tropical curve Γ\Gamma and a divisor DD in the canonical linear system on Γ\Gamma, we give a purely combinatorial condition to decide whether there is a smooth curve XX over a non-Archimedean field whose stable reduction has Γ\Gamma as its dual tropical curve together with a effective canonical divisor KXK_X that specializes to DD. Along the way, we develop a moduli-theoretic framework to understand Baker's specialization of divisors from algebraic to tropical curves as a natural toroidal tropicalization map in the sense of Abramovich-Caporaso-Payne.

Keywords

Cite

@article{arxiv.1710.06401,
  title  = {Realizability of tropical canonical divisors},
  author = {Martin Moeller and Martin Ulirsch and Annette Werner},
  journal= {arXiv preprint arXiv:1710.06401},
  year   = {2017}
}

Comments

36 pages, 10 figures, improved exposition (including a new discussion of algorithmic aspects) as well as a correction in Example 6.5, comments welcome!