NumCosmoDistancedilation_scale

The dilation scale is the spherically averaged distance for perturbations along and orthogonal to the line of sight, $$D_V(z) = \left[D_{H_0}^2 D_t(z)^2 \frac{cz}{H(z)} \right]^{1/3},$$ where $D_t(z)$ is the transverse comoving distance [Eq. $\eqref{eq:def:Dt}$], $c$ is the speed of light [ncm_c_c()] and $H(z)$ is the Hubble function [nc_hicosmo_H()]. See [Eisenstein et al. (2005)][XEisenstein2005] [arXiv].

This function computes the dimensionless dilation scale: $$D_V^\star(z) = \left[D_t(z)^2 \frac{z}{E(z)} \right]^{1/3} = \frac{D_V(z)}{D_{H_0}},$$ where $E(z)$ is the normalized Hubble function [nc_hicosmo_E2()].