Slides of 5 lectures at XV Brazilian School on Cosmology and ...

Photon to baryon r<strong>at</strong>ioNumber density <strong>of</strong> baryons <strong>at</strong> the volume average iswhere ¯γ ′ 0 ≡ 1¯H0 d¯γdtf B≡ ¯Ω B0/¯Ω M0.¯n B= 3 ¯H 2 0 ¯Ω B08πG m p= 11.2f B ¯Ω M0h 2(¯γ 0− ¯γ ′ 0 )2 m −3 ,∣t0, m p is the proton mass,Hence the average photon to baryon r<strong>at</strong>io isη Bγ= ¯n B¯n γ= 2.736 × 10−8 f B ¯ΩM0¯γ 3 0 h2(¯γ 0− ¯γ ′ 0 )2 ,as compared to η FLRW = 2.736 × 10 −8 f BΩ Mh 2 .15th <strong>Brazilian</strong> <strong>School</strong> on Cosmology and Gravit<strong>at</strong>ion, August 2012 – p.85/143