A poor man's positive energy theorem: II. Null geodesics

TL;DR

This paper proves the positivity of energy for certain asymptotically flat spacetimes using null rigidity theorems, extending the positive energy theorem to broader classes of solutions.

Contribution

It introduces a new proof of the positive energy theorem leveraging Galloway's null rigidity theorem for specific spacetime domains.

Findings

Positivity of energy established for stationary, asymptotically flat spacetimes.

Utilizes null rigidity theorem to extend positive energy results.

Provides a new approach to the positive energy theorem in general relativity.

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.