English

Non-Archimedean geometry of Artin fans

Algebraic Geometry 2018-12-27 v2

Abstract

The purpose of this article is to study the role of Artin fans in tropical and non-Archimedean geometry. Artin fans are logarithmic algebraic stacks that can be described completely in terms of combinatorial objects, so called Kato stacks, a stack-theoretic generalization of K. Kato's notion of a fan. Every logarithmic algebraic stack admits a tautological strict morphism ϕX:XAX\phi_\mathcal{X}:\mathcal{X}\rightarrow\mathcal{A}_\mathcal{X} to an associated Artin fan. The main result of this article is that, on the level of underlying topological spaces, the natural functorial tropicalization map of X\mathcal{X} is nothing but the non-Archimedean analytic map associated to ϕX\phi_\mathcal{X} by applying Thuillier's generic fiber functor. Using this framework, we give a reinterpretation of the main result of Abramovich-Caporaso-Payne identifying the moduli space of tropical curves with the non-Archimedean skeleton of the corresponding algebraic moduli space.

Keywords

Cite

@article{arxiv.1603.07589,
  title  = {Non-Archimedean geometry of Artin fans},
  author = {Martin Ulirsch},
  journal= {arXiv preprint arXiv:1603.07589},
  year   = {2018}
}

Comments

29 pages, 3 figures. In many parts rewritten to take into account new developments from arXiv:1704.03806, several technical inaccuracies corrected, and significantly improved exhibition. To appear in Advances in Mathematics