Einar H. Gu­mundsson, Gunnlaugur Bj÷rnsson og Pßll Jakobsson

Mˇttekin: 2. september 2004 - Vef˙tgßfa: 22. desember 2004


We investigate the possible use of photon dispersion mechanisms in cosmology. In particular, we consider ordinary dispersion in a cold electron plasma, as well as recently proposed photon dispersion due to vacuum quantum fluctuations. We also consider dispersion due to a finite photon mass, for comparison. The dispersion time delay of radiation from extragalactic sources such as gamma-ray bursts (GRBs), their afterglows and flares in active galactic nuclei is estimated for the various mechanisms and the results compared. Finally it is shown how the delay can be used in a new cosmological test to differentiate between world models.

pdf sŠkja grein (pdf) [raust.is/2004/2/09/]