2010/06/07 by Timothy J. Hollowood, Hollowood, Timothy J., G.M. Shore +2
Physics and Astronomy · #Advanced Fiber Laser Technologies #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Laser-Plasma Interactions and Diagnostics #Quantum Electrodynamics and Casimir Effect #Quantum optics and atomic interactions #hep-th
paper · pdf · doi:10.48550/arxiv.1006.1238
11 pages
arxiv created 2010/06/07 · openalex publication_date 2010/06/07 · arxiv updated 2010/06/08 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
It is now well-known that vacuum polarisation in QED can lead to superluminal low-frequency phase velocities for photons propagating in curved spacetimes. In a series of papers, we have shown that this quantum phenomenon is dispersive and have calculated the full frequency dependence of the refractive index, explaining in detail how causality is preserved and various familiar results from quantum field theory such as the Kramers-Kronig dispersion relation and the optical theorem are realised in curved spacetime. These results have been criticised in a recent paper by Akhoury and Dolgov arXiv:1003.6110 [hep-th], who assert that photon propagation is neither dispersive nor necessarily causal. In this note, we point out a series of errors in their work which have led to this false conclusion.