Author(s): Simeon Djambov, Alice Marcotte, François Gallaire, and Pier Giuseppe Ledda From coating curved parts to creeping lava, thin-film gravitational drainage over complex surfaces can produce abrupt accumulation, usually associated with sharp edges or defects. Here, experiments, simulations, and asymptotics show that a smooth saddle alone generates a logarithmically singular rid… [Phys. Rev. Lett. 137, 164002] Published Thu Oct 15, 2026