English

Hyperelliptic curves, minitwistors, and spacelike Zoll spaces

Differential Geometry 2025-02-18 v1 Algebraic Geometry

Abstract

We construct a compact minitwistor space from a hyperelliptic curve with real structure and show that it yields a lot of new Lorentzian Einstein-Weyl spaces all of which are diffeomorphic to the 3-dimensional deSitter space. These structures are real analytic, admit a circle symmetry and moreover, all their spacelike geodesics are closed and simple. The number of the nodes of minitwistor lines on the minitwistor space is equal to the genus of the hyperelliptic curve and is taken arbitrarily. These Einstein-Weyl structures deform as the hyperelliptic curves deform, and so have (2g1)(2g-1)-dimensional moduli space, where gg is the genus of the hyperelliptic curve. A relationship between the minitwistor spaces recently obtained by Hitchin from ALE gravitational instantons is also given for Aodd_{\rm odd}-type.

Keywords

Cite

@article{arxiv.2502.11388,
  title  = {Hyperelliptic curves, minitwistors, and spacelike Zoll spaces},
  author = {Nobuhiro Honda},
  journal= {arXiv preprint arXiv:2502.11388},
  year   = {2025}
}

Comments

55 pages, 10 figures