Figure 8

Figure 8: The evolution of the covariant variable Φ, defined in Equation (304View Equation) (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 w = 13 [(2 − 32𝜖)tanh (N − 50) − (1 − 32𝜖)], 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 [177].)