wcosmo.wcosmo.dDLdz

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

The Jacobian for the conversion of redshift to luminosity distance.

\[\frac{dd_{L}}{z} = d_C(z; H_0, \Omega_{m,0}, w_0) + (1 + z) d_{H} E(z; \Omega_{m, 0}, w0)\]

Here \(d_{C}\) is comoving distance and \(d_{H}\) is the Hubble distance.

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:

dDLdz: array_like

The derivative of the luminosity distance with respect to redshift in Mpc

Notes

This function does not have a direct analog in the astropy cosmology objects, but is needed for accounting for expressing distributions of redshift as distributions over luminosity distance.