Flat centroaffine surfaces with the degenerate second fundamental form and vanishing Pick invariant in

Compact spacelike surfaces in the 3-dime

Compact spacelike surfaces in the 3-dimensional de Sitter space with non-degenerate second fundamental form

✍ Juan A. Aledo; Alfonso Romero 📂 Article 📅 2003 🏛 Elsevier Science 🌐 English ⚖ 127 KB

In this paper, we establish several sufficient conditions for a compact spacelike surface with non-degenerate second fundamental form in the 3-dimensional de Sitter space to be spherical. With this aim, we develop a formula for these surfaces which involves the mean and Gaussian curvatures of the fi