wcosmo.wcosmo.lookback_time

wcosmo.wcosmo.lookback_time(z, H0, Om0, w0=-1, method='pade')

Compute the lookback time using an analytic integral of the Pade approximation.

\[t_{L} = t_{H} \int_{0}^{z} \frac{dz'}{(1 + z')E(z'; \Omega_{m,0}, w_0)}\]

Parameters:

z: array_like

Redshift

H0: array_like

The Hubble constant in km/s/Mpc

Om0: array_like

The matter density fraction

w0: array_like

The (constant) equation of state parameter for dark energy

Returns:

lookback_time: array_like

The lookback time in km / s / Mpc