2022/06/10 by Xiaolong Li, Yongjia Zhang, Li, Xiaolong +1
Physics and Astronomy · Mathematics · #Black Holes and Theoretical Physics #Geometric Analysis and Curvature Flows #Geometry and complex manifolds
paper · pdf · doi:10.48550/arxiv.2206.04870
We prove that a closed oriented Einstein four-manifold is either anti-self-dual or (after passing to a double Riemann cover if necessary) Kähler-Einstein, provided that λ2 ≥ -(S)/(12), where λ2 is the middle eigenvalue of the self-dual Weyl tensor W+ and S is the scalar curvature. The same conclusion holds for closed oriented four-manifolds with δW+=0.