Viewing the Cosmos Through the Highly Redshifted 21-cm Line

Redshifted neutral-hydrogen emission could reveal the first astrophysical sources and the thermal history of intergalactic gas. This seminar reviews the promise and observational challenges of the 21-centimetre signal, HERA power-spectrum limits and their heating implications. It also examines mutual coupling between antennas and the mitigation needed for future analyses.