2019/11/24 by Catarina Cosme, Cosme, Catarina
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · pdf · doi:10.48550/arxiv.1911.10622
openalex publication_date 2019/11/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We introduce an oscillating scalar field coupled to the Higgs that can account for all dark matter in the Universe. Due to an underlying scale invariance of this model, the dark scalar only acquires mass after the electroweak phase transition. We discuss the dynamics of this dark matter candidate, showing that it behaves like dark radiation until the Electroweak phase transition and like non-relativistic matter afterwards. In the case of a negative coupling to the Higgs field, the scalar gets a vacuum expectation value after the electroweak phase transition and may decay into photons, although being sufficiently long-lived to account for dark matter. We show that, within this scenario, for a mass of 7 keV, the model can explain the observed galactic and extra-galactic 3.5 keV X-ray line. Nevertheless, it will be very difficult to probe this model in the laboratory in the near future.