Cosmological radiation density with non-standard neutrino-electron interactions

Abstract

Non-standard interactions (NSI) between neutrinos and electrons can significantly modify the decoupling of neutrinos from the plasma. These interactions have two effects on the overall picture: (i) they alter neutrino oscillations though matter effects and (ii) they modify the scattering and annihilation processes involving neutrinos and electrons and positrons. We study the role of non-universal and flavour-changing NSI in the decoupling and how they impact the determination of the effective number of neutrinos, $N_{eff}$. We examine the degeneracies between NSI parameters and we compare the expected sensitivity from future cosmological surveys with the current limits from terrestrial experiments. We outline the complementarity between both approaches.

arXiv comment5 pages, 2 figures. Based on arXiv:2105.08168. Proceedings for the 17th International Conference on Topics in Astroparticle and Underground Physics

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