Exploring Dark Matter Halos: Linking Theoretical Predictions with Observational Data from surveys DES and ACT

Abstract

Traditionally, Dark Matter(DM) halos have been defined on the basis of spherical overdensity with their boundaries defined using a fixed overdensity scaled to the critical or mean density of the universe, like R200m, R200c, Rvir. Although these definitions gives us a good estimate of the halo boundary, they do not directly contain the physical processes that govern the growth of a halo. Splashback radius came out as a good, physically motivated alternative that is defined as the radius at which infalling material reaches its first apocenter in a halo. Much work has been done in recent years on observational detection of splashback radius using data from Dark Energy Survey (DES), Atacama Cosmology Telescope(ACT), etc. In this project I, looked at the recently released Year-6 data of DES and DR6 data from ACT and tried to bridge the gap between theoretical and observational predictions