I have two questions about Quintessence module in CAMB.
1) What is the sence of constant "norm" which equals 1d122 in function Vofphi(phi,deriv) in the code?
2) Why in this "sigma model" Vofphi= norm*exp(sqrt(3/2)*phi), although according to correct conformal transformation Vofphi \sim exp(sqrt(2/3)*phi)? I studied paper "f(R) gravity" Antonio De Felice and Shinji Tsujikawa.
Quintessence module

 Posts: 13
 Joined: July 25 2013
 Affiliation: ROE at University of Edinburgh
Quintessence module
The correct value of norm is
norm = 3*CP%h0**2/c**2*1000**2
This is for it to match the normalization for the other components (matter, radiation) given by the variable grhom.
Example,
omegab = grhom*CP%omegav
Try with a constant potential
Vofphi = norm*CP%omegav
norm = 3*CP%h0**2/c**2*1000**2
This is for it to match the normalization for the other components (matter, radiation) given by the variable grhom.
Example,
omegab = grhom*CP%omegav
Try with a constant potential
Vofphi = norm*CP%omegav