Speaker
Dr
Yong TANG
(KIAS)
Description
We propose a ultraviolet complete theory for cold dark matter(CDM) and sterile neutrinos that can accommodate both cosmological data and neutrino oscillation experiments within $1\sigma$ level. We assume a new U(1)_X dark gauge symmetry which is broken at MeV scale resulting light dark photon. Such a light mediator for DM's self-scattering and scattering-off sterile neutrinos can resolve three controversies for cold DM on small cosmological scales: cusp vs. core, too-big-to-fail and missing satellites problems.
We can also accommodate eV scale sterile neutrinos as the hot dark matter(HDM) and can fit some neutrino anomalies from neutrino oscillation experiments within $1\sigma$. Finally the right amount of HDM can make a sizable contribution to dark radiation, and also helps to reconcile the tension between the data on the tensor-to-scalar ratio reported by Planck and BICEP2 Collaborations
