Speaker
Description
We explore the capture of radiation in the cosmic neutrino and photon backgrounds by primordial black holes (PBHs) as a novel probe of the PBH abundance. We model this process as a gravitational interaction that effectively modifies the cosmic expansion history, the evolution of radiation and dark matter (in the form of PBH) densities, and the perturbed continuity and Euler equations of dark matter and radiation. We investigate the impact of this effect on the CMB temperature and E-mode polarization anisotropies. Using Planck data, we derive constraints on the PBH abundance as a function of mass, and present forecasts for future CMB surveys. We find these constraints to be comparable to the current limits at the high-mass end of the spectrum, providing an independent complementary probe in this range.