## Publications of SPP2026

On this site you find preprints and publications produced within the projects and with the support of the DFG priority programme „Geometry at Infinity“.

Let \(M^n, n \in \{4,5,6\}\), be a compact, simply connected *n*-manifold which admits some Riemannian metric with non-negative curvature and an isometry group of maximal possible rank. Then any smooth, effective action on \(M^n\) by a torus \(T^{n-2}\) is equivariantly diffeomorphic to an isometric action on a normal biquotient. Furthermore, it follows that any effective, isometric circle action on a compact, simply connected, non-negatively curved four-dimensional manifold is equivariantly diffeomorphic to an effective, isometric action on a normal biquotient.

Journal | Math. Z. |

Volume | 276 |

Pages | 133--152 |

Link to preprint version | |

Link to published version |

**Related project(s):****11**Topological and equivariant rigidity in the presence of lower curvature bounds