English

Nonnegatively curved fixed point homogeneous manifolds in low dimensions

Differential Geometry 2011-06-13 v3

Abstract

Let GG be a compact Lie group acting isometrically on a compact Riemannian manifold MM with nonempty fixed point set MGM^G. We say that MM is fixed-point homogeneous if GG acts transitively on a normal sphere to some component of MGM^G. Fixed-point homogeneous manifolds with positive sectional curvature have been completely classified. We classify fixed-point homogeneous Riemannian manifolds in dimensions 3 and 4 and determine which nonnegatively curved simply-connected 4-manifolds admit a smooth fixed-point homogeneous circle action with a given orbit space structure.

Keywords

Cite

@article{arxiv.0911.1254,
  title  = {Nonnegatively curved fixed point homogeneous manifolds in low dimensions},
  author = {Fernando Galaz-Garcia},
  journal= {arXiv preprint arXiv:0911.1254},
  year   = {2011}
}

Comments

To appear in Geom. Dedicata. Main difference with v1: "Linear" circle actions on $S^2\times S^2$ and $CP^2\#\pm CP^2$ are now called "extendable actions". Typos corrected