English

Positive intermediate Ricci curvature on cohomogeneity one manifolds in low dimensions

Differential Geometry 2025-11-13 v2

Abstract

We explore existence of invariant metrics with positive intermediate Ricci curvature on closed, low-dimensional cohomogeneity one manifolds. For a certain cohomogeneity one Spin(4)\mathsf{Spin}(4)-action on S3×CP2S^3 \times \mathbb{C}\mathrm{P}^2, we construct an invariant metric with positive 4th-intermediate Ricci curvature and show it cannot admit one with positive 3rd-intermediate Ricci curvature. We further establish similar symmetry obstructions to positive curvature for S3×S3S^3 \times S^3, S3×S4S^3 \times S^4, and several families of cohomogeneity one manifolds.

Keywords

Cite

@article{arxiv.2507.17920,
  title  = {Positive intermediate Ricci curvature on cohomogeneity one manifolds in low dimensions},
  author = {Elahe Khalili Samani and Lawrence Mouillé},
  journal= {arXiv preprint arXiv:2507.17920},
  year   = {2025}
}

Comments

improved exposition throughout, and added open questions to the introduction