Boosted dark matter from primordial black holes produced in a first-order phase transition

During a cosmological first-order phase transition in a dark sector, fermion dark matter particles chi can form macroscopic Fermi balls that collapse to primordial black holes (PBHs) under certain conditions. The evaporation of the PBHs produces a boosted chi flux, which may be detectable if chi couples to visible matter. We consider the interaction of chi with electrons, and calculate signals of the dark matter flux in the XENON1T, XENONnT, Super-Kamiokande and Hyper-Kamiokande experiments. A correlated gravitational wave signal from the phase transition can be observed at THEIA and mu Ares. An amount of dark radiation measurable by CMB-S4 is an epiphenomenon of the phase transition.