Astrophysical limits on quantum gravity motivated birefringence
Reinaldo J. Gleiser, Carlos N. Kozameh
Abstract
We obtain observational upper bounds on a class of quantum gravity related birefringence effects, by analyzing the presence of linear polarization in the optical and ultraviolet spectrum of some distant sources. In the notation of Gambini and Pullin we find $χ< 10^{-3}$.