2025/06/18 by Arnab Chaudhuri, Chaudhuri, Arnab
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Neutrino Physics Research #Astrophysics and Cosmic Phenomena
paper · pdf · doi:10.48550/arxiv.2506.15485
We propose a unified framework based on sterile neutrinos propagating in large extra dimensions (LED) and coupled to a pseudo-Nambu-Goldstone boson (Majoron) arising from spontaneous lepton number violation. In this setup, the lightest Kaluza-Klein (KK) sterile neutrino serves as warm dark matter, higher KK modes decay invisibly producing a relativistic Majoron contributing to the effective number of neutrino species (Delta Neff), and active neutrinos undergo invisible decay. This model addresses dark radiation, dark matter, and neutrino anomalies within a minimal, testable framework. We present the Boltzmann evolution of relevant species, identify the viable parameter space, and highlight implications for CMB-S4, Lyman-alpha, and neutrino observatories.