2022/08/06 by Yupeng Yang, Yang, Yupeng
Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #General Relativity and Quantum Cosmology (gr-qc)
paper · pdf · doi:10.48550/arxiv.2208.03458
openalex publication_date 2022/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In the mixed dark matter scenarios consisting of primordial black holes (PBHs) and weakly interacting massive particles (WIMPs), WIMPs can be accreted onto PBHs to form ultracompact minihalos (UCMHs) with a density spike in the early universe. Compared with the classical dark matter halo, UCMHs are formed earlier and have a higher density of center. Since the annihilation rate is proportional to the squared number density of WIMPs, it is expected that WIMPs annihilation within UCMHs is enhanced and has influences on the early universe. Between the time of recombination and matter-radiation equality, the energy released from WIMPs annihilation within UCMHs is injected into the Universe resulting in CMB y-type distortion. We investigate these effects and derive the upper limits on the abundance of PBHs taking advantage of the observational results of Far Infrared Absolute Spectrophotometer (FIRAS). We find that for the WIMPs mass range 1≤ mχ≤ 1000~\rm GeV, the upper limits on the abundance of PBHs are 5× 10-3≤ Ω\rm PBH≤ 5× 10-2.