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: (_O_m, _O_/\) = (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).