Properties beyond mass for unresolved haloes across redshift and cosmology using correlations with local halo environment by Sujatha Ramakrishnan et al. on Tuesday 22 November

The structural and dynamic properties of the dark matter halos, though an

important ingredient in understanding large-scale structure formation, require

more conservative particle resolution than those required by halo mass alone in

a simulation. This reduces the parameter space of the simulations, more

severely for high-redshift and large-volume mocks which are required by the

next-generation large sky surveys. Here, we incorporate redshift and cosmology

dependence into an algorithm that assigns accurate halo properties such as

concentration, spin, velocity, and spatial distribution to the sub-resolution

haloes in a simulation. By focusing on getting the right correlations with halo

mass and local tidal anisotropy $\alpha$ measured at $4 \times$ halo radius,

our method will also recover the correlations of these small scale structural

properties with the large-scale environment, i.e., the halo assembly bias at

all scales greater than $5 \times$ halo radius. We find that the distribution

of halo properties is universal with redshift and cosmology. By applying the

algorithm to a large volume simulation $(600 h^{-1}{\rm Mpc})$, we can access

the $30-500$ particle haloes, thus gaining an order of magnitude in halo mass

and two to three orders of magnitude in number density at $z=2-4$. This

technique reduces the cost of mocks required for the estimation of covariance

matrices, weak lensing studies, or any large-scale clustering analysis with

less massive haloes.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2112.15305v2