Assume a flat (Omega_k = 0) cosmological model with H_0 = 71/km/s/Mpc and
Omega_M = 0.27, and graphically compare the following cosmological distances:
D_C(z), D_A(z), D_L(z) and naive Hubble distance: D_H(z) = c * z / H_0
(see Hogg 2000 and Davis & Lineweaver 2004)
