Prospects of Future CMB Anisotropy Probes for Primordial Black Holes
  Cascade of particles injected as Hawking Radiation from Primordial Black
Holes (PBH) can potentially change the cosmic recombination history by ionizing
and heating the intergalactic medium, which results in altering the anisotropy
spectra of the Cosmic Microwave Background (CMB). In this paper, we study the
expected sensitivity of several future CMB experiments in constraining the
abundance of PBHs distributed in $10^{15}\sim10^{17}$ g mass window according
to four mass functions: the monochromatic, log-normal, power-law and critical
collapse models. Our result shows that future experiments, such as CMB-S4 and
PICO, can improve current {\it{Planck}} bounds by about two orders of
magnitudes. All regions in PBH parameter space that are allowed by current CMB
data, including monochromatically distributed PBHs with mass heavier than $4
\times 10^{16}$ grams, can be excluded by upcoming missions with high
significance.
