On the stability of stationary surfaces in S14

Similarly to minimal surfaces in Riemannian manifolds, spacelike surfaces in Lorentzian manifolds with zero mean curvature are also characterized as critical points for the area functional. However, the stability aspects of the variational problems for these two kinds of surfaces are completely different. In this paper we study the stability of spacelike surfaces with zero mean curvature in the four-dimensional de Sitter space S14.