Cosmology from Nx2pt Analyses of SKAO Wide-Area Surveys

Abstract

SKAO surveys will provide an unprecedented window into the large-scale structure of the universe through HI 21cm galaxy and intensity mapping surveys, and radio continuum surveys. We present forecasts for the cosmological constraining power of ``$N\times 2\mathrm{pt}$'' analyses -- which combine galaxy clustering, galaxy weak lensing, galaxy-galaxy lensing signals and 21cm Intensity Maps. By assuming cosmology surveys from an SKA-Mid AA4, we show that such an $N\times 2\mathrm{pt}$ analysis will be able to deliver measurements of $\sim 1\%$ precision on $\Lambda$CDM cosmological parameters. We also explore dynamical dark energy in the $w_0,w_a$ model, the sum of neutrino masses ${\mathrm{M}}_{\nu }$, and the background curvature ${\Omega }_{\mathrm{k}}$.

Published in Advancing Astrophysics with the SKA II (AASKAII), 2026 (arXiv:2606.20366). Report-no:AASKAII/Harrison01. Advancing Astrophysics with the SKA II (AASKAII) outlines the transformative scientific advances that will be enabled by the SKA telescopes