English

The Einstein-Weyl spaces associated to Segre quartic surfaces

Differential Geometry 2024-12-16 v2 Algebraic Geometry

Abstract

We find explicit examples of compact minitwistor spaces of genus one, whose Einstein-Weyl spaces have a connected component that is diffeomorphic to the de Sitter space. The induced Einstein-Weyl structure on it is Lorenzian, real-analytic, whose spacelike geodesics are all closed and simple. The identity component of the automorphism group of the Einstein-Weyl structure is the circle and therefore the structure is not isomorphic to the standard de Sitter structure. We show that these Einstein-Weyl structures deform as the Segre surfaces deform and converge to the standard de Sitter structure. The minitwistor spaces we study are the so-called Segre quartic surfaces. They have a real pair of nodes, which play a crucial role in proving the above results. These singularities also allow us to construct explicit examples of non-compact complex surfaces that do not admit any compactification.

Keywords

Cite

@article{arxiv.2208.13567,
  title  = {The Einstein-Weyl spaces associated to Segre quartic surfaces},
  author = {Nobuhiro Honda and Fuminori Nakata},
  journal= {arXiv preprint arXiv:2208.13567},
  year   = {2024}
}

Comments

v2: 45 pages, 7 figures. the main theorems substantially improved and new theorems added. Title updated, Section 1 completely rewritten, Section 2 compressed with some additional material, Section 4 completely rewritten with a new proof, a new Section 5 added, figures in Section 3 replaced

R2 v1 2026-06-25T02:03:19.136Z