English

Valuative compactifications of analytic varieties

Algebraic Geometry 2025-08-13 v2 Complex Variables Number Theory

Abstract

Let XX be an algebraic variety over C\mathbf{C}. We define a canonical compactification X ⁣X^{\!\urcorner} of the complex analytic space X(C)X(\mathbf{C}) by adding a Berkovich space over a trivially valued field at the boundary. The construction is functorial with respect to proper morphisms and preserves many properties, such as normality, regularity, etc. We prove a partial GAGA theorem in this setting : there is an equivalence between the categories of coherent sheaves on XX and X ⁣X^{\!\urcorner}, and it induces bijections on global sections. The results still hold if C\mathbf{C} is replaced by a complete non-trivially valued field kk, and complex analytic spaces by Berkovich analytic spaces over kk.

Keywords

Cite

@article{arxiv.2503.18643,
  title  = {Valuative compactifications of analytic varieties},
  author = {Jérôme Poineau},
  journal= {arXiv preprint arXiv:2503.18643},
  year   = {2025}
}

Comments

41 pages; v2: added Remark 5.19 to show that the cohomology of the compactification may be different from the algebraic cohomology

R2 v1 2026-06-28T22:32:14.536Z