English

Compactified Jacobians as Mumford models

Algebraic Geometry 2025-01-07 v2

Abstract

We show that relative compactified Jacobians of one-parameter smoothings of a nodal curve of genus g are Mumford models of the generic fiber. Each such model is given by an admissible polytopal decomposition of the skeleton of the Jacobian. We describe the decompositions corresponding to compactified Jacobians explicitly in terms of the auxiliary stability data and find, in particular, that in degree g there is a unique compactified Jacobian encoding slop stability, and it is induced by the tropical break divisor decomposition.

Keywords

Cite

@article{arxiv.1912.03653,
  title  = {Compactified Jacobians as Mumford models},
  author = {Karl Christ and Sam Payne and Tif Shen},
  journal= {arXiv preprint arXiv:1912.03653},
  year   = {2025}
}

Comments

25 pages. Final version, to appear in Trans. Amer. Math. Soc

R2 v1 2026-06-23T12:39:12.936Z