José Fonseca, Benedict Bahr-Kalus, Mario Ballardini, Matilde Barberi-Squarotti, Steven Cunnington, Sêcloka L. Guedezounme, Dionysios Karagiannis, Samantha J. Rossiter, Ziad Sakr, Cora Uhlemann, Stefano Camera, Bikash R. Dinda, Cláudio Gomes, Roy Maartens, Mário G. Santos

The origins of the universe remain one of the biggest mysteries in modern cosmology. While the Planck satellite has provided a wealth of information about the early universe, there is still much to be discovered. The Square Kilometre Array Observatory (SKAO) offers a unique opportunity to probe the universe's infancy, going beyond the current limitations of our knowledge. By measuring the power spectrum of biased tracers of the dark matter distribution on the largest cosmological scales and exploring beyond 2-point statistics, SKAO will enable us to refine our understanding of the primordial universe, including the shape of the inflationary power spectrum and the presence of primordial non-Gaussianity. In this chapter we will review recent works looking at the potential of SKAO's surveys, and how synergies with other surveys can revolutionize our understanding of the origins of the cosmos.