English

Fill Radius and the Fundamental Group

Differential Geometry 2009-07-27 v2 Geometric Topology

Abstract

In this note we relate the geometric notion of fill radius with the fundamental group of the manifold. We prove: ''Suppose that a closed Riemannian manifold M satisfies the property that its universal cover has bounded fill radius. Then the fundamental group of M is virtually free.'' We explain the relevance of this theorem to some conjectures on positive isotropic curvature and 2-positive Ricci curvature.

Keywords

Cite

@article{arxiv.0906.4497,
  title  = {Fill Radius and the Fundamental Group},
  author = {Mohan Ramachandran and Jon Wolfson},
  journal= {arXiv preprint arXiv:0906.4497},
  year   = {2009}
}

Comments

8 pages

R2 v1 2026-06-21T13:17:23.409Z