Negative time delay of light by a gravitational concave lens
Abstract
Gravitational lens models, some of which might act like a concave lens, have been recently investigated by using a static and spherically symmetric modified spacetime metric that depends on the inverse distance to the nth power [T. Kitamura et al., Phys. Rev. D 87, 027501 (2013)]. We reexamine the time delay of light in a gravitational concave lens as well as a gravitational convex one. The frequency shift due to the time delay is also investigated. We show that the sign of the time delay in the lens models is the same as that of the deflection angle of light. The size of the time delay decreases with increase in the parameter n. We also discuss possible parameter ranges that are relevant to pulsar timing measurements in our Galaxy.
 Publication:

Physical Review D
 Pub Date:
 October 2014
 DOI:
 10.1103/PhysRevD.90.084026
 arXiv:
 arXiv:1404.2720
 Bibcode:
 2014PhRvD..90h4026N
 Keywords:

 04.40.b;
 95.30.Sf;
 98.62.Sb;
 Selfgravitating systems;
 continuous media and classical fields in curved spacetime;
 Relativity and gravitation;
 Gravitational lenses and luminous arcs;
 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 16 pages, 7 figures. arXiv admin note: text overlap with arXiv:1307.6637