The Hubble Tension as a Signal of low-scale Leptogenesis and Neutrino Mass Generation
Abstract:
In this talk based on Arxiv:1909.04044 and ongoing work, I will show that the presence of a primordial population of majorons together with their very feeble interactions with neutrinos (lam~ 10^{-13}) can substantially ameliorate the outstanding Hubble tension. The majoron is a neutrinophilic pseudo-Goldstone boson that can naturally be linked to the neutrino mass mechanism in scenarios with a spontaneously broken global U(1)L symmetry. I will argue that majoron masses around the eV-scale can be associated to the explicit breaking of global symmetries by planck-scale physics. I will further show that within the same set up, the GeV-scale sterile neutrinos that can be responsible for generating active neutrino masses and leptogenesis via neutrino oscillations can, as a result of their decays, also provide the right primordial majoron population to account for the Hubble tension. Thus, providing a link between low-scale leptogenesis, neutrino mass generation and the Hubble tension.
Zoom link: IPPP Seminars (Thursday at 2 pm UK time)