Giulia Gubitosi
Title: Planck-scale induced birefringence and Cosmic Microwave Background
polarization data
Abstract: Some models of spacetime quantization predict a minute effect of
birefringence for the propagation of photons. For Cosmic Microwave Background (CMB)
photons, which have some degree of linear polarization, this results in a rotation
of their polarization direction. The effect is greatly amplified by their long time
of propagation, and could have observably large implications for analyses of CMB
polarization.
For the most studied model of quantum-spacetime-induced birefringence, characterized
by a single length scale lambda, available BOOMERanG 2003 and WMAP data can be
used to establish a bound of Planck-length significance lambda<0.41*10^-35 m.