{ "id": "2308.02777", "version": "v1", "published": "2023-08-05T03:10:34.000Z", "updated": "2023-08-05T03:10:34.000Z", "title": "On some rigidity theorems of Q-curvature", "authors": [ "Yiyan Xu", "Shihong Zhang" ], "comment": "23 pages, accepted by manuscripta mathematica", "categories": [ "math.DG" ], "abstract": "In this paper, we investigate the rigidity of Q-curvature. Specifically, we consider a closed, oriented $n$-dimensional ($n\\geq6$) Riemannian manifold $(M,g)$ and prove the following results under the condition $\\int_{M} \\nabla R\\cdot\\nabla \\mathrm{Q}\\mathrm{d} V_g\\leq0$. (1) If $(M,g)$ is locally conformally flat with nonnegative Ricci curvature, then $(M,g)$ is isometric to a quotient of $\\mathbb{R}^n$, $\\mathbb{S}^n$, or $\\mathbb{R}\\times\\mathbb{S}^{n-1}$. (2) If $(M,g)$ has $\\delta^2 W=0$ with nonnegative sectional curvature, then $(M,g)$ is isometric to a quotient of the product of Einstein manifolds. Additionally, we investigate some rigidity theorems involving Q-curvature about hypersurfaces in simply-connected space forms. We also show the uniqueness of metrics with constant scalar curvature and constant Q-curvature in a fixed conformal class.", "revisions": [ { "version": "v1", "updated": "2023-08-05T03:10:34.000Z" } ], "analyses": { "subjects": [ "53C24", "53C18" ], "keywords": [ "rigidity theorems", "constant scalar curvature", "einstein manifolds", "riemannian manifold", "nonnegative sectional curvature" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable" } } }