Best-fit results of equation (8) to the RRM rms as a function of the redshift computed from the GRM filtered sample. The gas density is taken from the LOS extracted from the MHD simulation of the primordial stochastic model with α_s = 0.0. The case with B_f independent of δ_g is assumed here. Top-left and top-right: 2D distributions (dots), and 1-sigma and 2-sigma confidence level contours (solid lines) of the fit parameters α, B_f, 0, and A_rrm. Bottom-left: RRM rms measured in redshift bins (circles) and best-fit curve (solid) and its error range (grey-shaded area). The fit component of the sole filaments is also shown (dashed line) along with its uncertainty (shaded area). Bottom-right: Evolution with redshift z of the best-fit filament physical (solid line) and comoving magnetic field strength (dashed). The error range is also shown (shaded areas).