Glimpses of Mathematics, Now and Then: A Celebration of Karen Uhlenbeck's 80th birthday

Abstract : In this talk , I shall discuss my joint works with Poning Chen , Mu Tao Wang and Yi Kai Wang We find solution of an old problem in general relativity by defining good quasilocal conserved quantities in GR . In particular, by taking limit of this quasilocal quantity, we were able to define the total angular momentum of an isolated spacetime that is independent of the ambiguity coming from supertranslation . This was a problem open for sixty years .