Manifolds with nonnegative curvature operator of the second kind

X Li - Communications in Contemporary Mathematics, 2024 - World Scientific
We investigate the curvature operator of the second kind on Riemannian manifolds and
prove several classification results. The first one asserts that a closed Riemannian manifold …

Holonomy restrictions from the curvature operator of the second kind

J Nienhaus, P Petersen, M Wink, W Wylie - Differential Geometry and its …, 2023 - Elsevier
We show that an n-dimensional Riemannian manifold with n-nonnegative or n-nonpositive
curvature operator of the second kind has restricted holonomy SO (n) or is flat. The result …

Manifolds with -Positive Curvature Operator of the Second Kind

X Li - The Journal of Geometric Analysis, 2022 - Springer
We show that a closed four-manifold with 4 1 2-positive curvature operator of the second
kind is diffeomorphic to a spherical space form. The curvature assumption is sharp as both …

Product manifolds and the curvature operator of the second kind

X Li - Pacific Journal of Mathematics, 2024 - msp.org
We investigate the curvature operator of the second kind on product Riemannian manifolds
and obtain some optimal rigidity results. For instance, we prove that the universal cover of an …

Kähler manifolds and the curvature operator of the second kind

X Li - Mathematische Zeitschrift, 2023 - Springer
This article aims to investigate the curvature operator of the second kind on Kähler
manifolds. The first result states that an m-dimensional Kähler manifold with 3 2 (m 2-1) …

New Sphere Theorems under Curvature Operator of the Second Kind

X Li - arxiv preprint arxiv:2407.13847, 2024 - arxiv.org
We investigate Riemannian manifolds $(M^ n, g) $ whose curvature operator of the second
kind $\mathring {R} $ satisfies the condition\begin {equation*}\alpha …

Einstein manifolds of negative lower bounds on curvature operator of the second Kind

H Cheng, K Wang - arxiv preprint arxiv:2411.13912, 2024 - arxiv.org
We demonstrate that $ n $-dimension closed Einstein manifolds, whose smallest eigenvalue
of the curvature operator of the second kind of $\mathring {R} $ satisfies $\lambda_1\ge …

The curvature operator of the second kind in dimension three

H Fluck, X Li - The Journal of Geometric Analysis, 2024 - Springer
This article aims to understand the behavior of the curvature operator of the second kind
under the Ricci flow in dimension three. First, we express the eigenvalues of the curvature …