Speaker: Professor Xiao Zhang (from Chinese Academy of Sciences) Time: 12-1PM, Tuesday, 9 August Room: 707A, Carslaw Title: the conformal Laplacian operator and the mass of asymptotically flat manifolds Abstract: we define the eventual nonnegativity for the first Neumann eigenvalue of the conformal Laplacian operator on asymptotically flat manifolds. We prove the positivity of the mass under this condition when the manifolds don’t contain black holes. We also discuss the black hole’s case.