Upper panel: redshift z_min at the centre of a matched disc in a Poincaré space as a function of matched circle radius α, for Ω_m = 0.26,0.28,0.30,0.32 as curved solid, dotted, dot-dashed and dashed lines, respectively (almost indistinguishable). Redshifts z_min = 10,40, and 200 are indicated as illustrations of epochs of successively rarer expected formation of galaxies with Population III stars. Lower panel: corresponding injectivity radius of the Universe r_inj.