A poor man's positive energy theorem: II. Null geodesics
arXiv:gr-qc/0406077 · doi:10.1088/0264-9381/21/18/008
Abstract
We show that positivity of energy for stationary, or strongly uniformly Schwarzschildian, asymptotically flat, non-singular domains of outer communications can be proved using Galloway's null rigidity theorem.
Latex2e, 24 A4 pages, minor changes