Homology and homotopy groups of the complement of certain family of fibers in a critical point problem. Pintea, Cornel (2005) Balkan Journal of Geometry and its Applications (BJGA)
Hypersurfaces in ℝ n and critical points in their external region P. M. G. Manchón (2002) Czechoslovak Mathematical Journal In this paper we study the hypersurfaces M n given as connected compact regular fibers of a differentiable map f : ℝ n + 1 → ℝ , in the cases in which f has finitely many nondegenerate critical points in the unbounded component of ℝ n + 1 - M n .