Positive energy theorem

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In general relativity, the positive energy theorem states that, assuming the dominant energy condition, the mass of an asymptotically flat spacetime is non-negative; furthermore, the mass is zero only for Minkowski spacetime.

The original proof of the theorem for ADM mass was provided by Schoen and Shing-Tung Yau in 1979 using variational methods. Edward Witten gave a simpler proof in 1981 based on the use of spinors, inspired by positive energy theorems in the context of supergravity. An extension of the theorem for the Bondi mass was given by Ludvigsen and Vickers, Gary Horowitz and Malcolm Perry, and Schoen and Yau.

Gary Gibbons, Stephen Hawking, Horowitz and Perry proved extensions of the theorem to asymptotically anti-de Sitter spacetimes and to Einstein-Maxwell theory. The mass of an asymptotically anti-de Sitter spacetime is non-negative and only equal to zero for anti-de Sitter spacetime. In Einstein-Maxwell theory, for a spacetime with electric charge $Q$ and magnetic charge $P$ , the mass of the spacetime satisfies

$M \geq \sqrt{Q^2 + P^2},$

with equality for the Majumdar-Papapetrou extremal black hole solutions.

[edit] References

R. Schoen and S.-T. Yau, "On the positive mass conjecture in general relativity", Commun. Math. Phys. 65, 45 (1979).
R. Schoen and S.-T. Yau, "Proof of the positive mass theorem. II", Commun. Math. Phys. 79, 231 (1981).
E. Witten, "A new proof of the positive energy theorem", Commun. Math. Phys. 80, 381 (1981).
M. Ludvigsen and J. A. G. Vickers, "The positivity of the Bondi mass", J. Phys. A 14, L389 (1981).
G. T. Horowitz and M. J. Perry, "Gravitational mass cannot become negative", Phys. Rev. Lett. 48, 371 (1982).
R. Schoen and S. T. Yau, "Proof that the Bondi mass is positive", Phys. Rev. Lett. 48, 369 (1982).
G. W. Gibbons, S. W. Hawking, G. T. Horowitz and M. J. Perry, "Positive mass theorems for black holes", Commun. Math. Phys. 88, 295 (1983).