Function Calc_scale

Calc_scale.pro calculates the scale factor for given time t and parameters $\Omega_M$, $\Omega_\Lambda$ and w. At the current version, the parameter isn't used for the calculation. For some basic reference about the w parameter, see [3,4]. However you can also use the function without using this parameter (see IVB below ). The function checks if the passed parameters would result in a bouncing universe which means that the universe has a turning point in its past, that is, it collapsed from infinite size to a finite radius and is now reexpanding. If the functions detects parameters which describe such a bouncing universe, it returns a large negative number (see sections IVC and V below).