Figure 6

Figure 6: Comparison between N-body simulations and the two fitting formulas in the f (R) model (4.83View Equation) with n = 1∕2. The circles and triangles show the results of N-body simulations with and without the chameleon mechanism, respectively. The arrow represents the maximum value of k(= 0.08h Mpc −1) by which the perturbation theory is valid. (Left) The fitting formula by Smith et al. [540] is used to predict Pnon− GR and PGR. The solid and dashed lines correspond to the power spectra with and without the chameleon mechanism, respectively. For the chameleon case cnl(z) is determined by the perturbation theory with cnl(z = 0) = 0.085. (Right) The N-body results in [479] are interpolated to derive Pnon−GR without the chameleon mechanism. The obtained P non−GR is used for the HS fitting formula to derive the power spectrum P in the chameleon case. From [371].