Description
The Square Kilometre Array (SKA) will be an extremely fast, efficient survey instrument, with the ability to detect and catalogue a range of different tracer populations out to high redshift, over vast regions of the sky. I will give an overview of the cosmological applications of "full-sky" radio surveys with the SKA, with a particular focus on the potential for testing fundamental physics (e.g. General Relativity, dark energy, and inflation) by using HI galaxy surveys and 21cm intensity maps to probe never-before-seen distance scales and redshift regimes.