Neutrino masses, matter-antimatter asymmetry, dark matter, and supermassive black hole formation explained with Majorons

TL;DR

This paper proposes a Majoron-based model that links neutrino masses, dark matter, matter-antimatter asymmetry, and early supermassive black hole formation, with testable predictions via space telescope observations.

Contribution

It introduces a singlet Majoron model with electromagnetic anomaly, connecting multiple cosmological phenomena in a unified framework.

Findings

Majorons at the eV scale can be dark matter candidates detectable by telescopes.

Decay of Majorons can produce photons that facilitate black hole seed formation.

The model explains neutrino masses, baryon asymmetry, dark matter, and early black holes simultaneously.

Abstract

The spontaneous breaking of a global lepton number symmetry can result in a (pseudo) Nambu-Goldstone boson known as the Majoron. We study a singlet Majoron model that couples to two Higgs doublets in which the lepton number current develops an electromagnetic anomaly, allowing the decay of Majorons into photons. We focus on Majorons at the eV scale with an enhanced anomaly and show that it serves as a dark matter candidate whose decay signals can be probed by space telescope observations. Furthermore, if the decay produces Lyman-Werner photons, heavy black hole seeds can be generated via the direct collapse mechanism and evolve into the active galactic nuclei we observe at high redshifts. Our framework thus simultaneously addresses the origin of neutrino masses, the baryon asymmetry of the Universe, the nature of dark matter, and the formation of high redshift supermassive black holes.