2011/04/30 by Lijing Shao, Bo-Qiang Ma · 1 citation
Physics and Astronomy · #Birefringence #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Electromagnetism #Fermi Gamma-ray Space Telescope #Lorentz transformation #Noncommutative and Quantum Gravity Theories #Photon #Photon polarization #Physics #Polarization (electrochemistry) #Quantum electrodynamics #Quantum mechanics #Vacuum polarization #astro-ph.HE #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.83.127702
published as Phys.Rev.D83:127702,2011 · 4 latex pages, 2 figures, short version for publication in PRD. For a detailed long version, please look at the first version of this arXiv paperarXiv:1104.4438v1
arxiv created 2011/06/08 · openalex publication_date 2011/06/10 · arxiv updated 2011/06/13 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In the electromagnetism of loop quantum gravity, two helicities of a photon have different phase velocities and group velocities, termed as ``vacuum birefringence''. Two novel phenomenons, ``peak doubling'' and ``depolarization'', are expected to appear for a linearly polarized light from astrophysical sources. We show that the criteria to observe these two phenomenons are the same. Further, from recently observed \ensuremathγ-ray polarization from Cygnus X-1, we obtain an upper limit \ensuremath∼8.7\ifmmode×\else\texttimes\fi10^\ensuremath-12 for the Lorentz-violating parameter \ensuremathχ, which is the most firm constraint from well-known systems. We also suggest analyzing the possible existence of ``peak doubling'' through Fermi-LAT gamma-ray bursts.