Self-interacting Dark Radiation
High Energy Physics - Phenomenology
2014-02-28 v3 Cosmology and Nongalactic Astrophysics
Abstract
We consider a simple class of models where dark radiation has self-interactions and therefore does not free stream. Such dark radiation has no anisotropic stress (or viscosity), leaving a distinct signature on the CMB angular power spectrum. Specifically we study a possibility that hidden gauge bosons and/or chiral fermions account for the excess of the effective number of neutrino species. They have gauge interactions and remain light due to the unbroken hidden gauge symmetry, leading to \Delta N_{\rm eff} \simeq 0.29 in some case.
Cite
@article{arxiv.1305.6521,
title = {Self-interacting Dark Radiation},
author = {Kwang Sik Jeong and Fuminobu Takahashi},
journal= {arXiv preprint arXiv:1305.6521},
year = {2014}
}
Comments
14 pages, 3 figures; v3: references added, published version