Achronal averaged null energy condition
Abstract
The averaged null energy condition (ANEC) requires that the integral over a complete null geodesic of the stressenergy tensor projected onto the geodesic tangent vector is never negative. This condition is sufficient to prove many important theorems in general relativity, but it is violated by quantum fields in curved spacetime. However there is a weaker condition, which is free of known violations, requiring only that there is no selfconsistent spacetime in semiclassical gravity in which ANEC is violated on a complete, achronal null geodesic. We indicate why such a condition might be expected to hold and show that it is sufficient to rule out closed timelike curves and wormholes connecting different asymptotically flat regions.
 Publication:

Physical Review D
 Pub Date:
 September 2007
 DOI:
 10.1103/PhysRevD.76.064001
 arXiv:
 arXiv:0705.3193
 Bibcode:
 2007PhRvD..76f4001G
 Keywords:

 04.20.Gz;
 04.62.+v;
 Spacetime topology causal structure spinor structure;
 Quantum field theory in curved spacetime;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Theory
 EPrint:
 8 pages, RevTeX