Primordial Black Hole Reformation and Constraints and an Expanding Soliton Solution

概要

Primordial black holes (PBHs) from Planck-mass to supermassive black holes produce a variety of interesting phenomena. I first present the PBH reformation process, where clouds of extremely light PBHs can recollapse into heavier PBHs before evaporating. By transitioning to a matter-dominated era, the formation probability of PBHs is greatly increased and does not therefore require any initial clustering. The larger reformed PBH population could survive to the present day, emitting high energy radiation potentially detectable by the next generation cosmic ray experiments. Chirping gravitational waves generated by O(10 M_sun) binary black hole mergers have been detected by the LIGO-VIRGO-KAGRA experiments, with speculation that some events are generated by PBH mergers. We show that the dark matter halo that accretes around PBHs can distinguish them from stellar evolution black holes, and gravitational lensing of chirping gravitational waves can reveal their extended structure and prove their primordial origin. I then present gas heating constraints on these dressed PBHs (PBH + dark halo) as well as other extended dark compact objects. In addition to modifying the point-mass dynamical friction formalism to include finite-size effects, the accretion disk emission sensitively depends on the object radius. Finally, I discuss a Friedberg-Lee-Sirlin Q-ball solution where the inclusion of a Yukawa force destabilizes the Q-ball at large charges. Surprisingly, the unstable Q-balls do not collapse under this attractive force but instead experience runaway expansion.

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