Let us bury the prehistoric $h$: arguments against using $h^{-1}{rm Mpc}$ units in observational cosmology. (arXiv:2002.07829v1 [astro-ph.CO])
<a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_A/0/1/0/all/0/1">Ariel G. Sanchez</a>

It is common to express cosmological measurements in units of $h^{-1}{rm
Mpc}$. Here, we review some of the complications that originate from this
practice. A crucial problem caused by these units is related to the
normalization of the matter power spectrum, which is commonly characterized in
terms of the linear-theory rms mass fluctuation in spheres of radius
$8,h^{-1}{rm Mpc}$, $sigma_8$. This parameter does not correctly capture the
impact of $h$ on the amplitude of density fluctuations. We show that the use of
$sigma_8$ has caused critical misconceptions for both the so-called $sigma_8$
tension regarding the consistency between low-redshift probes and cosmic
microwave background data, and the way in which growth-rate estimates inferred
from redshift-space distortions are commonly expressed. We propose to abandon
the use of $h^{-1}{rm Mpc}$ units in cosmology and to characterize the
amplitude of the matter power spectrum in terms of $sigma_{12}$, defined as
the mass fluctuation in spheres of radius $12,{rm Mpc}$, whose value is
similar to the standard $sigma_8$ for $hsim 0.67$.

It is common to express cosmological measurements in units of $h^{-1}{rm
Mpc}$. Here, we review some of the complications that originate from this
practice. A crucial problem caused by these units is related to the
normalization of the matter power spectrum, which is commonly characterized in
terms of the linear-theory rms mass fluctuation in spheres of radius
$8,h^{-1}{rm Mpc}$, $sigma_8$. This parameter does not correctly capture the
impact of $h$ on the amplitude of density fluctuations. We show that the use of
$sigma_8$ has caused critical misconceptions for both the so-called $sigma_8$
tension regarding the consistency between low-redshift probes and cosmic
microwave background data, and the way in which growth-rate estimates inferred
from redshift-space distortions are commonly expressed. We propose to abandon
the use of $h^{-1}{rm Mpc}$ units in cosmology and to characterize the
amplitude of the matter power spectrum in terms of $sigma_{12}$, defined as
the mass fluctuation in spheres of radius $12,{rm Mpc}$, whose value is
similar to the standard $sigma_8$ for $hsim 0.67$.

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