English

Instability of the fundamental group for non-collapsed Ricci-limits

Differential Geometry 2025-05-26 v1

Abstract

We construct two sequences of closed 44-dimensional manifolds with non-negative Ricci curvature, diameter bounded from above by 11, and volume bounded from below by v>0v>0, with different fundamental groups but with the same Gromov-Hausdorff limit. This provides a negative answer to the question posed in [J. Pan. Ricci Curvature and Fundamental Groups of Effective Regular Sets. Journal of Mathematical Study, 58(1):3--21, 2025].

Keywords

Cite

@article{arxiv.2505.17263,
  title  = {Instability of the fundamental group for non-collapsed Ricci-limits},
  author = {Camillo Brena},
  journal= {arXiv preprint arXiv:2505.17263},
  year   = {2025}
}