6 upvotes, 1 direct replies (showing 1)
View submission: Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
Small black holes might have been formed directly by collapsing from small fluctuations in density in the early universe. These are called primordial black holes.
Currently, primordial black holes are predicted theoretically but have but been observed.
Comment by amaurea at 20/07/2022 at 19:23 UTC
3 upvotes, 2 direct replies
Currently, primordial black holes are predicted theoretically but have but been observed.
I don't thinks standard cosmology predicts primordial black holes. The simplest initial conditions that match our observations don't have large enough short-wavelength fluctuations to produce primordial black holes, whether large or small ones. To get primordial black holes to form you need more complicated initial conditions. We can't exclude those, but they are not favored by Occam's razor.