Superradiant pion clouds around primordial black holes

Journal Article · 14 July 2022 · Journal of Cosmology and Astroparticle Physics

DOI: https://doi.org/10.1088/1475-7516/2022/07/026 · OSTI ID:1979364

Ferraz, Paulo B. ^[1]; Kephart, Thomas W. ^[2]; Rosa, João G. ^[3]

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1. Universidade de Coimbra (Portugal); Universidad de Granada (Spain); Vanderbilt Univ., Nashville, TN (United States)
2. Vanderbilt University, Nashville, TN (United States)
3. Universidade de Coimbra (Portugal)

Here, we show that highly spinning primordial black holes of mass M ~ 10₁₂ kg, potentially born in a matter-dominated era after inflation, can produce clouds of pions in their vicinity via the superradiant instability, with densities up to that of nuclear matter. We discuss the electromagnetic signatures of this process, via neutral pion decay and charged pion annihilation into photons, computing in particular their contribution to the isotropic gamma-ray background. This allows us to place upper bounds on the abundance of such primordial black holes that are comparable to the ones obtained from Hawking evaporation. We also discuss the possibility of directly observing such clouds in high-redshift superclusters.

• Research Organization: Vanderbilt University, Nashville, TN (United States)
• Sponsoring Organization: FCT Fellowship; USDOE Office of Science (SC)
• Grant/Contract Number: SC0019235
• OSTI ID: 1979364
• Journal Information: Journal of Cosmology and Astroparticle Physics, Journal Name: Journal of Cosmology and Astroparticle Physics Journal Issue: 07 Vol. 2022; ISSN 1475-7516
• Publisher: Institute of Physics (IOP)Copyright Statement
• Country of Publication: United States
• Language: English