Cosmology with massive neutrinos II: on the universality of the halo
  mass function and bias
  We use a large suite of N-body simulations to study departures from
universality in halo abundances and clustering in cosmologies with
non-vanishing neutrino masses. To this end, we study how the halo mass function
and halo bias factors depend on the scaling variable $\sigma^2(M,z)$, the
variance of the initial matter fluctuation field, rather than on halo mass $M$
and redshift $z$ themselves. We show that using the variance of the cold dark
matter rather than the total mass field, i.e., $\sigma^2_{cdm}(M,z)$ rather
than $\sigma^2_{m}(M,z)$, yields more universal results. Analysis of halo bias
yields similar conclusions: When large-scale halo bias is defined with respect
to the cold dark matter power spectrum, the result is both more universal, and
less scale- or $k$-dependent. These results are used extensively in Papers I
and III of this series.
