Mika Gelowicz

Calculation of Electron-Positron Pair Production by the Cosmic Photon Background as a function of redshift

Goal: Calculating the rate of the Electron-Positron Pair Production from Cosmic Background (CB) photons considering the effects of redshift.

Methods: Analytic calculations, model comparison, line-of-sight integration

The cosmic background radiation consists of photons whose energies range across the whole electromagnetic spectrum – from the Cosmic Radio Background (CRB) up to the Cosmic X-ray Background (CXB). Active galactic nuclei, galaxies, heated dust, and the surface of last scattering itself and many more sources contribute to this background. As the number and luminosity of those sources changes with redshift, their contribution to the CB changes as well. Additionally, there is the effect of the expanding universe itself, which stretches the lights’ wavelength.

By splitting the Cosmic Background into a number of blackbody radiators and letting these evolve with redshift, it is possible to calculate the pair production rate of electrons and positrons – not just for the local universe, but for a variety of redshifts.