Resumen de A Ricci-type flow on globally null manifolds and its gradient estimates

M.H.A. Hamed, Fortuné Masamba, S. Ssekajja

• Locally, a screen integrable globally null manifold M splits through a Riemannian leaf M0 of its screen distribution and a null curve C tangent to its radical distribution. The leaf M0 carries a lot of geometric information about M and, in fact, forms a basis for the study of expanding and nonexpanding horizons in black hole theory. In the present paper, we introduce a degenerate Ricci-type flow in M0 via the intrinsic Ricci tensor of M. Several new gradient estimates regarding the flow are proved.