Halo formation from Yukawa forces in the very early Universe

Journal Article · 28 November 2023 · Physical Review. D.

DOI: https://doi.org/10.1103/physrevd.108.103543 · OSTI ID:2255196

Domènech, Guillem  ^[1]; Inman, Derek  ^[2]; Kusenko, Alexander ^[3]; Sasaki, Misao ^[4]

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1. Leibniz University Hannover (Germany); University of California, Los Angeles, Los Angeles, California
2. University of Tokyo, Chiba (Japan); RIKEN iTHEMS, Saitama (Japan)
3. University of Tokyo, Chiba (Japan); University of California, Los Angeles, CA (United States)
4. University of Tokyo, Chiba (Japan); Kyoto University (Japan); National Taiwan University, Taipei (Taiwan)

If long-range attractive forces exist and are stronger than gravity then cosmic halo formation can begin in the radiation-dominated era. We study a simple realization of this effect in a system where dark matter fermions have Yukawa interactions mediated by scalar particles, analogous to the Higgs boson in the standard model. We develop a self-consistent description of the system including exact background dynamics of the scalar field, and precise modeling of the fermion density fluctuations. For the latter, we provide accurate approximations for the linear growth as well as quantitative modeling of the nonlinear evolution using N-body simulations. We find that halo formation occurs exponentially fast and on scales substantially larger than simple estimates predict. Here, the final fate of these halos remains uncertain, but could be annihilation, dark stars, primordial black holes, or even the existence of galaxy-sized halos at matter-radiation equality. More generally, our results demonstrate the importance of mapping scalar-mediated interactions onto structure formation outcomes and constraints for beyond the standard model theories.

• Research Organization: University of California, Los Angeles, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP)
• Grant/Contract Number: SC0009937
• OSTI ID: 2255196
• Alternate ID(s): OSTI ID: 2222839
• Journal Information: Physical Review. D., Journal Name: Physical Review. D. Journal Issue: 10 Vol. 108; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English