Question

Suppose the difference between matter and antimatter in the early universe were 1 part in 108 instead of 1 part in 109.
(a.) Evaluate the temperature at which deuterium begins to form.
(b.) At what age does this occur?
(c.) Evaluate the temperature and the corresponding time of radiation decoupling (when hydrogen atoms form).

Answer 1

25 f=-710-8-0.42e (a) + 2 gives kT kT kT 2.22 x10° eV 1.0×109 K T=_= 25(8.617×10-5eV/K) 25k 1.5×1010 s1/2 . K 1.5×1010 s1/2"K 1.0x109 K 225 s (c) f-100.42e-ETo kT 50 24 kT gives KT E, 24k 13.6 eV 6600 K 24(8.617×10-) eV/K) 1/2 t-2 1.5x1010 s12.K 1.5x1010 s1/2 . K 6600 K =5.2×1012 s=1.6×105 y These times are not very different from those computed using 10-タfor the matter. antimatter imbalance

I hope you understood the problem and got your answers, If yes rate me!! or else comment for a better solutions