  I shall discuss the Chen-Wang-Yau quasilocal angular momentum, which is
defined based on the theory of optimal isometric embedding and quasilocal mass
of Wang-Yau, and the limits of which at spatial and null infinity of an
isolated gravitating system. This is based on joint work with Po-Ning Chen,
Jordan Keller, Ye-Kai Wang, and Shing-Tung Yau.
