An Introduction to Modern Astrophysics · Problem 17.21
Close Binary Star Systems — Carroll & Ostlie
Physics — Astrophysics · black-holes-primordial
Problem
(a) Use dimensional arguments to combine the fundamental constants ℏ, c, and G into an expression that has units of mass. Evaluate your result, which is an estimate of the least massive primordial black hole formed in the first instant after the Big Bang. What is the mass in kilograms?
(b) What is the Schwarzschild radius for such a black hole?
(c) How long would it take light to travel this distance?
(d) What is the lifetime of this black hole before its evaporation?