Accretion Growth Limits for Primordial Black Holes in the Early Universe

A primordial black hole is born into the densest environment it will ever inhabit, and an obvious question follows: how much can it eat? If Bondi accretion from the radiation bath were efficient, holes could grow by large factors before the universe thins out, shifting every mass function upward and loosening the connection between formation mass and present mass that abundance arguments rely on. The literature has swung on this question, with early optimistic growth estimates later tempered by the realisation that the accretion flow itself, the expansion of the background, and the hole's motion all limit the intake. The headline computed values are: max growth factor lambda1 = 1.247e+00; max growth factor lambda01 = 1.020e+00. The study is a computation from stated assumptions, not a measurement, and the deposited script reproduces every number quoted.