English

The local geometry of compact homogeneous Lorentz spaces

Differential Geometry 2017-04-13 v1

Abstract

In 1995, S. Adams and G. Stuck as well as A. Zeghib independently provided a classification of non-compact Lie groups which can act isometrically and locally effectively on compact Lorentzian manifolds. In the case that the corresponding Lie algebra contains a direct summand isomorphic to the two-dimensional special linear algebra or to a twisted Heisenberg algebra, Zeghib also described the geometric structure of the manifolds. Using these results, we investigate the local geometry of compact homogeneous Lorentz spaces whose isometry groups have non-compact connected components. It turns out that they all are reductive. We investigate the isotropy representation and curvatures. In particular, we obtain that any Ricci-flat compact homogeneous Lorentz space is flat or has compact isometry group.

Keywords

Cite

@article{arxiv.1502.02622,
  title  = {The local geometry of compact homogeneous Lorentz spaces},
  author = {Felix Günther},
  journal= {arXiv preprint arXiv:1502.02622},
  year   = {2017}
}

Comments

20 pages. arXiv admin note: substantial text overlap with arXiv:1106.5539