0-tight surfaces with boundary and the total curvature of curves in surfaces
We study the notion of strong -stability for the context of closed hypersurfaces () with constant -th mean curvature immersed into the Euclidean sphere , where . In this setting, under a suitable restriction on the -th mean curvature , we establish that there are no -strongly stable closed hypersurfaces immersed in a certain region of , a region that is determined by a totally umbilical sphere of . We also provide a rigidity result for such hypersurfaces.
In this paper we study the -stability of closed hypersurfaces with constant -th mean curvature in Riemannian manifolds of constant sectional curvature. In this setting, we obtain a characterization of the -stable ones through of the analysis of the first eigenvalue of an operator naturally attached to the -th mean curvature.