学术报告（乐鹏宇 6.20）

Null Penrose inequality is an important case of the wellknown Penrose inequality on a null hypersurface. It conjectures the  relation between the area of the outmost marginally trapped surface and the Bondi mass at null infinity. Following the proposal of Christodoulou and Sauter, we employ the perturbation method to study the asymptotic geometry of null hypersurfaces at null infinity in a perturbed vacuum Schwarzshild spacetime. We explain how to apply this perturbation theory to prove null Penrose inequality on a nearly spherically symmetric null hypersurface in a perturbed vacuumSchwarzschild spacetime.