The Aemulus Project VI: Emulation of beyond-standard galaxy clustering statistics to improve cosmological constraints

Kavli Affiliate: Risa H. Wechsler

| First 5 Authors: Kate Storey-Fisher, Jeremy Tinker, Zhongxu Zhai, Joseph DeRose, Risa H. Wechsler

| Summary:

There is untapped cosmological information in galaxy redshift surveys in the
non-linear regime. In this work, we use the AEMULUS suite of cosmological
$N$-body simulations to construct Gaussian process emulators of galaxy
clustering statistics at small scales ($0.1-50 : h^{-1},mathrm{Mpc}$) in
order to constrain cosmological and galaxy bias parameters. In addition to
standard statistics — the projected correlation function
$w_mathrm{p}(r_mathrm{p})$, the redshift-space monopole of the correlation
function $xi_0(s)$, and the quadrupole $xi_2(s)$ — we emulate statistics
that include information about the local environment, namely the underdensity
probability function $P_mathrm{U}(s)$ and the density-marked correlation
function $M(s)$. This extends the model of AEMULUS III for redshift-space
distortions by including new statistics sensitive to galaxy assembly bias. In
recovery tests, we find that the beyond-standard statistics significantly
increase the constraining power on cosmological parameters of interest:
including $P_mathrm{U}(s)$ and $M(s)$ improves the precision of our
constraints on $Omega_m$ by 27%, $sigma_8$ by 19%, and the growth of
structure parameter, $f sigma_8$, by 12% compared to standard statistics. We
additionally find that scales below $sim6 : h^{-1},mathrm{Mpc}$ contain as
much information as larger scales. The density-sensitive statistics also
contribute to constraining halo occupation distribution parameters and a
flexible environment-dependent assembly bias model, which is important for
extracting the small-scale cosmological information as well as understanding
the galaxy-halo connection. This analysis demonstrates the potential of
emulating beyond-standard clustering statistics at small scales to constrain
the growth of structure as a test of cosmic acceleration.

| Search Query: ArXiv Query: search_query=au:”Risa H. Wechsler”&id_list=&start=0&max_results=3

Read More