\textif I understand correctly (because I didn't understand everything) for z=0.791, doing [latex]\Omega_b=M_b/M_{total}[/latex] is not a good approximation ?

well,  I redid the table with the same values but with 100 steps

The difference [latex]\Omega_b / \Omega_m[/latex] for z=0 et z=0.124 becomes minor : 0.05%

Can we say that [latex] M_b_\text{(t-1)}/ M_b_text{(t)}[/latex] from close to close ?

Edited February 17, 20196 yr by stephaneww

 

1 hour ago, stephaneww said:

 

well,  I redid the table with the same values but with 100 steps

The difference Ωb/Ωm for z=0 and z=0.124 becomes minor : 0.05%

merge then edit too late :

Can we say that [latex]M_\text{b(t-1)} =  M_\text{b(t)}[/latex] from close to close ?

Edited February 17, 20196 yr by stephaneww

In a short enough time frame one can safely assume the Baryon density will remain roughly the same or that the [latex] (1-z)^4[/latex] will provide a sufficient approximation. However that boils down to a choice of the accuracy one wants....one can for example make some reasonable assumptions that the chemical processes by and large are not undergoing a phase transition in our current universe. This simplifies a great deal as one must simply account for the expansion vs density relations under reasonable approximation

Edited February 17, 20196 yr by Mordred

Thank you for everything, Mordred.

If we assume, for example, that [latex]M_b * \Lambda= cst[/latex] then, when [latex]M_b[/latex] decreases [latex] \Lambda[/latex] increases inversely proportional.

Could this be a part of the explanation for the fact that it seems that the acceleration of expansion is also accelerated?

Edited February 18, 20196 yr by stephaneww