2021/05/22 by Diógenes, Rafael, Gadelha, Tiago, Ribeiro, Ernani · 1 citation
#Differential Geometry (math.DG) #FOS: Mathematics
paper · doi:10.48550/arxiv.2105.10829
In this paper, we prove that a compact quasi-Einstein manifold (Mn, g, u) of dimension n≥ 4 with boundary ∂ M, nonnegative sectional curvature and zero radial Weyl tensor is either isometric, up to scaling, to the standard hemisphere \BbbSn+, or g=dt2+ψ2(t)gL and u=u(t), where gL is Einstein with nonnegative Ricci curvature. A similar classification result is obtained by assuming a fourth-order vanishing condition on the Weyl tensor. Moreover, a new example is presented in order to justify our assumptions. In addition, the case of dimension n=3 is also discussed.