Quasilocal mass in general relativity

Understand

There have been many attempts to define the notion of quasilocal mass for a spacelike 2-surface in spacetime by the Hamilton-Jacobi analysis.

• The essential difficulty in this approach is to identify the right choice of the background configuration to be subtracted from the physical Hamiltonian.
• Quasilocal mass should be nonnegative for surfaces in general spacetime and zero for surfaces in flat spacetime.
• In this letter, we propose a new definition of gauge-independent quasilocal mass and prove that it has the desired properties.