English

A stratification of moduli of arbitrarily singular curves

Algebraic Geometry 2026-03-12 v5

Abstract

We introduce a new moduli stack Eg,n\mathscr{E}_{g,n} of ``equinormalized curves," closely related to the moduli space of all reduced, connected algebraic curves. We construct a stratification ΓEΓ\bigsqcup_\Gamma \mathscr{E}_\Gamma of Eg,n\mathscr{E}_{g,n} indexed by generalized dual graphs and prove that each stratum EΓ\mathscr{E}_{\Gamma} is a fiber bundle over a finite quotient of a product of \modulig,n\moduli_{g,n}s. The fibers are moduli schemes parametrizing subalgebras of a fixed algebra, and are in principle explicitly computable as locally closed subschemes of products of Grassmannians. We thus obtain a remarkably explicit geometric description of moduli of reduced curves with arbitrary singularities.

Keywords

Cite

@article{arxiv.2307.10013,
  title  = {A stratification of moduli of arbitrarily singular curves},
  author = {Sebastian Bozlee and Christopher Guevara and David Smyth},
  journal= {arXiv preprint arXiv:2307.10013},
  year   = {2026}
}

Comments

65 pages, substantial revisions