Kavli Affiliate: David N. Spergel
| First 5 Authors: Digvijay Wadekar, Leander Thiele, Francisco Villaescusa-Navarro, J. Colin Hill, Miles Cranmer
| Summary:
Complex systems (stars, supernovae, galaxies, and clusters) often exhibit low
scatter relations between observable properties (e.g., luminosity, velocity
dispersion, oscillation period, temperature). These scaling relations can
illuminate the underlying physics and can provide observational tools for
estimating masses and distances. Machine learning can provide a systematic way
to search for new scaling relations (or for simple extensions to existing
relations) in abstract high-dimensional parameter spaces. We use a machine
learning tool called symbolic regression (SR), which models the patterns in a
given dataset in the form of analytic equations. We focus on the
Sunyaev-Zeldovich flux$-$cluster mass relation ($Y_mathrm{SZ}-M$), the scatter
in which affects inference of cosmological parameters from cluster abundance
data. Using SR on the data from the IllustrisTNG hydrodynamical simulation, we
find a new proxy for cluster mass which combines $Y_mathrm{SZ}$ and
concentration of ionized gas ($c_mathrm{gas}$): $M propto
Y_mathrm{conc}^{3/5} equiv Y_mathrm{SZ}^{3/5} (1-A, c_mathrm{gas})$.
$Y_mathrm{conc}$ reduces the scatter in the predicted $M$ by $sim 20-30$% for
large clusters ($Mgtrsim 10^{14}, h^{-1} , M_odot$) at both high and low
redshifts, as compared to using just $Y_mathrm{SZ}$. We show that the
dependence on $c_mathrm{gas}$ is linked to cores of clusters exhibiting larger
scatter than their outskirts. Finally, we test $Y_mathrm{conc}$ on clusters
from simulations of the CAMELS project and show that $Y_mathrm{conc}$ is
robust against variations in cosmology, astrophysics, subgrid physics, and
cosmic variance. Our results and methodology can be useful for accurate
multiwavelength cluster mass estimation from current and upcoming CMB and X-ray
surveys like ACT, SO, SPT, eROSITA and CMB-S4.
| Search Query: ArXiv Query: search_query=au:”David N. Spergel”&id_list=&start=0&max_results=10