Figure 8.

The evolution of the covariant variable Φ, defined in Equation (298) (and not to be confused with the Bardeen potential), along a fundamental world-line. This is a mode that is well beyond the Hubble horizon at N = 0, about 50 e-folds before inflation ends, and remains super-Hubble through the radiation era. A smooth transition from inflation to radiation is modelled by , where ϵ is a small positive parameter (chosen as ϵ = 0.1 in the plot). Labels on the curves indicate the value of ρ₀/λ, so that the general relativistic solution is the dashed curve (ρ₀/λ = 0). (Figure taken from [122].)