There is slight different in the value of matter density between the Planck18
instance and the Planck’s paper. Similar problem also present in Planck15
.
I’m wondering where this slight difference come from.
(table 2 in Planck 2018 results. VI. Cosmological parameters)
>>> import astropy
>>> astropy.__version__
'5.3.3'
>>> from astropy.cosmology import Planck18
>>> Planck18.H0
<Quantity 67.66 km / (Mpc s)>
>>> Planck18.Om0
0.30966
>>> Planck18.Ode0
0.6888463055445441
(values in Planck18)