Dear Anthony,
I want to set coupling of quintessence with non relativistic matter. For this I use effective potential instead function Vofphi(phi,deriv):
Vofphi=Vofphi+[exp(-(\phi-\phi0)/sqrt(6))-1]*\rho_{DM0}/a**3
and their derivations,
where \phi0 - quintessence field today.
But now I need to check validity these changings. I decided to repeat the State Equation of Dark Energy in Starobinsky's gravity with fantom crossing at z \approx 1 in http://arxiv.org/abs/1101.0716 (Fig.1). These graphs were made in Jordan Frame. Can I reproduce this result in Frame of CAMBq?
I tried to plot
w_eff=w/(1-x)
where x=-[exp(-(phi-phi0)/sqrt(6))-1]*\rho_{DM0}/(\rho_{phi}*a**3)
and \rho_{phi}=phidot_a(i+1)**2/2 + aend**2*Vofphi(phi_a(i+1),0).
I took this expression according to article http://arxiv.org/abs/astro-ph/0510628.
Can you help me: is it right way? The thing is that I have got awful graph of State Equation of Dark Energy.
Thanks for your reply,
Anton.