English

Conformal flatness of compact three-dimensional Cotton-parallel manifolds

Differential Geometry 2023-10-17 v2

Abstract

A three-dimensional pseudo-Riemannian manifold is called essentially conformally symmetric (ECS) if its Cotton tensor is parallel but nowhere-vanishing. In this note we prove that three-dimensional ECS manifolds must be noncompact or, equivalently, that every compact three-dimensional Cotton-parallel pseudo-Riemannian manifold must be conformally flat.

Keywords

Cite

@article{arxiv.2301.06700,
  title  = {Conformal flatness of compact three-dimensional Cotton-parallel manifolds},
  author = {Ivo Terek},
  journal= {arXiv preprint arXiv:2301.06700},
  year   = {2023}
}

Comments

Fixed a typo and updated a reference; this is the last author-produced version before publication

R2 v1 2026-06-28T08:13:02.654Z