# Real-time cosmology with SKA

## TL;DR

This paper evaluates how redshift drift data from the SKA will enhance future cosmological parameter estimation, especially for dark energy models, by combining it with other observational data.

## Contribution

It demonstrates the significant potential of SKA's redshift drift measurements to improve constraints on dark energy and break parameter degeneracies in cosmological models.

## Key findings

- SKA1 data loosely constrains ΛCDM; SKA2 data constrains it well.
- Combining SKA data with E-ELT improves constraints nearly as much as SN, CMB, BAO.
- Redshift drift data significantly enhances dark energy parameter constraints.

## Abstract

In this work, we investigate what role the redshift drift data of Square Kilometre Array (SKA) will play in the cosmological parameter estimation in the future. To test the constraint capability of the redshift drift data of SKA-only, the $\Lambda$CDM model is chosen as a reference model. We find that using the SKA1 mock data, the $\Lambda$CDM model can be loosely constrained, while the model can be well constrained when the SKA2 mock data are used. When the mock data of SKA are combined with the data of the European Extremely Large Telescope (E-ELT), the constraints can be significantly improved almost as good as the data combination of the type Ia supernovae observation (SN), the cosmic microwave background observation (CMB), and the baryon acoustic oscillations observation (BAO). Furthermore, we explore the impact of the redshift drift data of SKA on the basis of SN+CMB+BAO+E-ELT in the $\Lambda$CDM model, the $w$CDM model, the CPL model, and the HDE model. We find that the redshift drift measurement of SKA could help to significantly improve the constraints on dark energy and could break the degeneracy between the cosmological parameters. Therefore, we conclude that redshift-drift observation of SKA would provide a good improvement in the cosmological parameter estimation in the future and has the enormous potential to be one of the most competitive cosmological probes in constraining dark energy.