Closeness to spheres of hypersurfaces with normal curvature bounded below

Constant mean curvature hypersurfaces foliated by spheres ∗

We ask when a constant mean curvature n-submanifold foliated by spheres in one of the Euclidean, hyperbolic and Lorentz–Minkowski spaces (En+1, Hn+1 or Ln+1), is a hypersurface of revolution. In En+1 and Ln+1 we will assume that the spheres lie in parallel hyperplanes and in the case of hyperbolic space Hn+1, the spheres will be contained in parallel horospheres. Finally, Riemann examples in L3...

Rigidity of minimal hypersurfaces of spheres with constant ricci curvature

ABSTRACT: Let M be a compact oriented minimal hypersurface of the unit n-dimensional sphere S. In this paper we will point out that if the Ricci curvature of M is constant, then, we have that either Ric ≡ 1 andM is isometric to an equator or, n is odd,Ric ≡ n−3 n−2 andM is isometric to S n−1 2 ( √ 2 2 )×S n−1 2 ( √ 2 2 ). Next, we will prove that there exists a positive number ̄(n) such that if ...

Heat Kernel Comparison on Alexandrov Spaces with Curvature Bounded Below

In this paper the comparison result for the heat kernel on Riemannian manifolds with lower Ricci curvature bound by Cheeger and Yau [CY81] is extended to locally compact path metric spaces (X, d) with lower curvature bound in the sense of Alexandrov and with sufficiently fast asymptotic decay of the volume of small geodesic balls. As corollaries we recover Varadhan’s short time asymptotic formu...

Metric measure spaces with Riemannian Ricci curvature bounded from below

In this paper we introduce a synthetic notion of Riemannian Ricci bounds from below for metric measure spaces (X, d,m) which is stable under measured Gromov-Hausdorff convergence and rules out Finsler geometries. It can be given in terms of an enforcement of the Lott, Sturm and Villani geodesic convexity condition for the entropy coupled with the linearity of the heat flow. Besides stability, i...

Hypersurfaces with Constant Mean Curvature in a Lorentzian Space Form