Probing $\Lambda$CDM cosmology with the Evolutionary Map of the Universe survey

TL;DR

The EMU radio survey has significant potential to improve constraints on cosmological models beyond $ ext{Lambda}$CDM, including dark energy, primordial non-Gaussianity, and modified gravity, through galaxy clustering and ISW effect analyses.

Contribution

This study evaluates EMU's ability to constrain extended cosmological models using galaxy power spectra and multi-tracer analysis, demonstrating its competitive advantage over existing methods.

Findings

EMU can measure dark energy parameters 35% more precisely than current constraints.

Constraints on primordial non-Gaussianity and modified gravity will improve up to a factor of 2.

Multi-tracer analysis enhances EMU's sensitivity to cosmological parameters.

Abstract

The Evolutionary Map of the Universe (EMU) is an all-sky survey in radio-continuum which uses the Australian SKA Pathfinder (ASKAP). Using galaxy angular power spectrum and the integrated Sachs-Wolfe effect, we study the potential of EMU to constrain models beyond $\Lambda$CDM (i.e., local primordial non-Gaussianity, dynamical dark energy, spatial curvature and deviations from general relativity), for different design sensitivities. We also include a multi-tracer analysis, distinguishing between star-forming galaxies and galaxies with an active galactic nucleus, to further improve EMU's potential. We find that EMU could measure the dark energy equation of state parameters around 35\% more precisely than existing constraints, and that the constraints on $f_{\rm NL}$ and modified gravity parameters will improve up to a factor $\sim2$ with respect to Planck and redshift space distortions measurements. With this work we demonstrate the promising potential of EMU to contribute to our understanding of the Universe.