{ "id": "2505.06631", "version": "v1", "published": "2025-05-10T12:43:46.000Z", "updated": "2025-05-10T12:43:46.000Z", "title": "Non-existence of cohomogeneity one Einstein metrics of two summands", "authors": [ "Hanci Chi" ], "comment": "This submission contains the non-existence result originally part of arXiv:2405.10836v3, now split off for clarity. We appreciate the valuable feedback from our readers", "categories": [ "math.DG" ], "abstract": "We prove the non-existence of cohomogeneity one Einstein metrics on a class of compact manifolds arising as double disk bundles, whose principal orbits split into two inequivalent irreducible summands. The proof uses a phase space barrier argument that yields a new obstruction to the existence of closed cohomogeneity one Einstein metrics, even when the principal orbits admit homogeneous Einstein metrics.", "revisions": [ { "version": "v1", "updated": "2025-05-10T12:43:46.000Z" } ], "analyses": { "subjects": [ "53C25" ], "keywords": [ "cohomogeneity", "non-existence", "orbits admit homogeneous einstein metrics", "principal orbits admit homogeneous einstein", "phase space barrier argument" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }