Peer-reviewedCC BY-SA 4.0Symmetry, Integrability and Geometry: Methods and Applications
Free Circle Actions and Positive Ricci Curvature on Manifolds with the Cohomology Ring of S2× S5
- 1Karlsruhe, Germany
Abstract
We classify which of the 672 oriented diffeomorphism types of closed, simply-connected spin 7-manifolds with the cohomology ring of S2× S5 admit a free circle action. In addition, we show that whenever such an action exists, there exist infinitely many pairwise non-equivalent free circle actions. Finally, in almost all cases where such an action exists, we construct invariant Riemannian metrics of positive Ricci curvature.
Related
- Positive sectional curvature and non-isometric circle actions on a family of eleven-spheres
- Weights of circle actions on oriented manifolds with isolated fixed points
- Minimal Two-Spheres and Manifolds with Positive Isotropic Curvature
- Positive scalar curvature on products of noncompact manifolds
- Sharp monotonicity for closed three-manifolds with positive scalar curvature
BibTeX
@article{reiser2026free,
title = {{Free Circle Actions and Positive Ricci Curvature on Manifolds with the Cohomology Ring of $S^2\times S^5$}},
author = {Philipp Reiser},
journal = {Symmetry, Integrability and Geometry: Methods and Applications},
year = {2026},
month = oct,
doi = {10.3842/sigma.2026.094},
url = {https://sigma-journal.com/2026/094/},
note = {CC BY-SA 4.0},
}
RIS
TY - JOUR
TI - Free Circle Actions and Positive Ricci Curvature on Manifolds with the Cohomology Ring of S^2× S^5
AU - Philipp Reiser
PY - 2026
DA - 2026/10/02
JO - Symmetry, Integrability and Geometry: Methods and Applications
DO - 10.3842/sigma.2026.094
UR - https://sigma-journal.com/2026/094/
AB - We classify which of the 672 oriented diffeomorphism types of closed, simply-connected spin 7-manifolds with the cohomology ring of S^2× S^5 admit a free circle action. In addition, we show that whenever such an action exists, there exist infinitely many pairwise non-equivalent free circle actions. Finally, in almost all cases where such an action exists, we construct invariant Riemannian metrics of positive Ricci curvature.
SN - 1815-0659
ER -