Detecting the power spectrum turnover with HI intensity mapping

Understand

A goal for pathfinder intensity mapping (IM) surveys will be detecting features in the neutral hydrogen (HI) power spectrum, which serve as conclusive evidence of cosmological signals.

• Observing such features at the expected scales in HI IM auto-correlations, where contribution from systematics is uncertain, will provide a more convincing cosmological detection.
• We demonstrate how the turnover, i.e.
• the peak of the power spectrum at ultra-large scales, can be detected with HI IM.