2020/08/31 by Jeong-Pyong Hong, Sunghoon Jung, Ke-Pan Xie · 109 citations
Mathematics · Physics and Astronomy · #Atomic and Subatomic Physics Research #Ball (mathematics) #Condensed matter physics #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Geometry #Mathematics #Particle physics #Phase transition #Physics #astro-ph.CO #hep-ph
paper · pdf · doi:10.1103/physrevd.102.075028
published in Physical review. D/Physical review. D. 102(7) (American Physical Society) · 11 pages, 5 figures. Accepted version for PRD
arxiv created 2020/10/15 · openalex publication_date 2020/10/23 · arxiv updated 2020/10/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We propose a novel dark matter (DM) scenario based on a first-order phase transition in the early Universe. If dark fermions acquire a huge mass gap between true and false vacua, they can barely penetrate into the new phase. Instead, they get trapped in the old phase and accumulate to form macroscopic objects, dubbed Fermi-balls. We show that Fermi-balls can explain the DM abundance in a wide range of models and parameter space, depending most crucially on the dark-fermion asymmetry and the phase transition energy scale (possible up to the Planck scale). They are stable by the balance between fermion's quantum pressure against free energy release, hence turn out to be macroscopic in mass and size. However, this scenario generally produces no detectable signals (which may explain the null results of DM searches), except for detectable gravitational waves for electroweak scale phase transitions; although the detection of such stochastic gravitational waves does not necessarily imply a Fermi-ball DM scenario.