Figure 1

Figure 1: Evolution of the cosmic scale factor as a function of $H0 (t − t0)$ . The present value of the scale factor $a0$ is set to unity; solid line: $(Ωm, Ω Λ) = (0.3,1.7 )$ , dotted line: $(0.3,0.7)$ , dot-dashed line: $(0.3,0.0)$ , long dashed line: $(1.0, 0.0)$ , short dashed line: $(3.0,0.0 )$ .