Real-time cosmology with SKA
  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.
