2013/08/31 by Chris Kelso, C. A. de S. Pires, Stefano Profumo +2 · 4 citations
Physics and Astronomy · #Astrophysics #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark energy #Dark matter #Dark radiation #Electroweak interaction #Gauge (firearms) #Large Hadron Collider #Particle physics #Particle physics theoretical and experimental studies #Physics #Physics beyond the Standard Model #Quantum mechanics #Standard Model (mathematical formulation) #Theoretical physics #Universe #astro-ph.CO #hep-ph
paper · pdf · doi:10.1140/epjc/s10052-014-2797-3
10 pages,7 figures. Matches Published EPJC version
arxiv created 2014/02/28 · openalex publication_date 2014/03/01 · arxiv updated 2015/06/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Recent observations suggest that the number of relativistic degrees of freedom in the early universe might exceed what is predicted in the standard cosmological model. If even a small, percent-level fraction of dark matter particles are produced relativistically, they could mimic the effect of an extra realistic species at matter–radiation equality while obeying BBN, CMB and Structure Formation bounds. We show that this scenario is quite naturally realized with a weak-scale dark matter particle and a high-scale “mother” particle within a well-motivated 3-3-1 gauge model, which is particularly interesting for being consistent with electroweak precision measurements, with recent LHC results, and for offering a convincing explanation for the number of generations in the Standard Model.