English

Real semi-stable degenerations, real-oriented blow-ups and straightening corners

Algebraic Geometry 2023-02-23 v2 Geometric Topology

Abstract

We study totally real semi-stable degenerations (and more generally, smooth semi-stable degenerations). Our goal is to describe the homeomorphism type of the real locus RXt\mathbf{R} X_t of the general fibre in terms of the special fibre. We give a general homeomorphism statement via the real-oriented blow-up of the family. Using this, we give more explicit descriptions of RXt\mathbf{R} X_t as a stratified space glued from (covers of) strata of the special fibre. We also give relative versions of the statements and consider the example of toric degenerations in order to link the technique to tropicalisation.

Keywords

Cite

@article{arxiv.2203.17097,
  title  = {Real semi-stable degenerations, real-oriented blow-ups and straightening corners},
  author = {Johannes Rau},
  journal= {arXiv preprint arXiv:2203.17097},
  year   = {2023}
}

Comments

31 pages, 8 figures; added references and various corrections