Exploring the role of SKA surveys with upcoming cosmic microwave background missions in probing primordial features (2212.14101v1)

Abstract: This present article is dedicated to thoroughly exploring the competency of the synergy of the upcoming Cosmic Microwave Background (CMB) missions and Square Kilometre Array (SKA) surveys in detecting features in the primordial power spectrum. Features are by definition specific scale-dependent modifications to the minimal power-law power spectrum. The functional form of the features depends on the inflationary scenarios taken into consideration. The identification of any conclusive deviation from the feature-less power-law power spectrum will allow us to largely fathom out the microphysics of the primordial universe. Here, we consider three vital theoretically motivated feature models, namely, Sharp feature signal, Resonance feature signal, and Bump feature. To investigate these features, we associate each feature model with a specific scale-dependent function called a template. Here we explore three distinct fiducial models for each feature model and for each fiducial model we compare the sensitivity of 36 different combinations of the cosmological surveys. We implement the Fisher matrix forecast method to obtain the possible constraints on the feature model parameters for the future CMB missions, namely, PICO, CORE-M5, LiteBIRD and CMB-S4 in synergy with upcoming SKA surveys, wherein we explore SKA-Cosmic Shear and SKA-Intensity Mapping surveys. Furthermore, the significance of combining EUCLID-Galaxy surveys with the SKA-Intensity Mapping survey is also explored. To consider the feasibility of propagating theoretical uncertainties of nonlinear scales in estimating the uncertainties on the feature parameters, we adopt redshift dependent upper limits of scales. To demonstrate the relative sensitivities of these future surveys towards the parameters of the feature models, we present a comparative analysis of all three feature models.