Introduction to Cosmology Ryden · Problem 9.1

Nucleosynthesis and the Early Universe

Physics — Astrophysics · big-bang-nucleosynthesis-helium-fraction

Problem

Suppose the neutron decay time were

\tau_n = 88

s instead of

\tau_n = 880

s, with all other physical parameters unchanged. Estimate

Y_{\max}

, the maximum possible mass fraction in

^4

He, assuming that all available neutrons are incorporated into

^4

He nuclei.