文摘
In this article, we prove pinching theorems for the first eigenvalue \(\lambda _1(M)\) of the Laplacian on compact Euclidean hypersurfaces involving the integrals of \(k\)-th mean curvature. Particularly, we show that under a suitable pinching condition, the hypersurface is starshaped and almost-isometric to a standard sphere. Based on our theorems, we prove some pinching results for the almost-Einstein and almost-umbilical hypersurfaces in Euclidean space.