Plots of DM variations with redshift for different parameters. The first three panels (a, b, and c) show the variation in the globally averaged Dispersion Measure (DM) as a function of redshift for the different free parameters in our model (i.e., ζ₀, α, and T_re). We show in panel a the DM-z variation for different ζ₀ models; in panel b the DM-z variation for different α models; and in panel c the DM-z variation for different T_re models. We used ζ₀ = 12, α = 1.4, and T_re = 1.9 × 10⁴ K as our fiducial model parameters in the analysis. For each case, we show the plots for five different parameter values. The last panel d shows the fiducial mock DM values (at true redshifts) for 100 samples along with the corresponding input model. The mock data were generated assuming a typical expectation from upcoming facilities such as the SKA.