An analytical solution in the complex plane for the luminosity distance
  in flat cosmology
  We present an analytical solution for the luminosity distance in spatially
flat cosmology with pressureless matter and the cosmological constant. The
complex analytical solution is made of a real part and a negligible imaginary
part. The real part of the luminosity distance allows finding the two
parameters $H_0$ and $\om$. A simple expression for the distance modulus for
SNs of type Ia is reported in the framework of the minimax approximation.
