Measuring baryon acoustic oscillations with future SKA surveys

TL;DR

This paper evaluates the potential of future SKA radio surveys to measure baryon acoustic oscillations, which are crucial for understanding cosmic expansion, and compares their effectiveness with optical surveys.

Contribution

It forecasts the capabilities of Phase 1 and 2 SKA surveys in BAO detection, highlighting their competitiveness and specific strengths in constraining cosmological parameters.

Findings

Phase 1 SKA intensity mapping can constrain the expansion rate at z ~ 2 to 2%.

SKA2 galaxy survey will outperform other planned experiments for z < 1.4.

SKA surveys are highly competitive with optical galaxy surveys for BAO measurements.

Abstract

The imprint of baryon acoustic oscillations (BAO) in large-scale structure can be used as a standard ruler for mapping out the cosmic expansion history, and hence for testing cosmological models. In this article we briefly describe the scientific background to the BAO technique, and forecast the potential of the Phase 1 and 2 SKA telescopes to perform BAO surveys using both galaxy catalogues and intensity mapping, assessing their competitiveness with current and future optical galaxy surveys. We find that a 25,000 sq. deg. intensity mapping survey on a Phase 1 array will preferentially constrain the radial BAO, providing a highly competitive 2% constraint on the expansion rate at z ~ 2. A 30,000 sq. deg. galaxy redshift survey on SKA2 will outperform all other planned experiments for z < 1.4.