Constraining the Generalized and Superfluid Chaplygin Gas Models with the Sandage–Loeb Test

The Sandage–Loeb (SL) test is a direct measurement of the cosmic expansion by probing the redshift drifts of quasi-stellar objects in the 'redshift desert' of 2<z<5. In this work, we investigate its constraints on the unified dark energy and dark matter models including the generalized Chaplygin gas and the superfluid Chaplygin gas. In addition, type Ia supernovae (SNIa) data and the distance ratios derived from the cosmic microwave background radiation and baryon acoustic oscillation observations (CMB/BAO) are also used. We find that the mock SL data gives the tightest constraints on the model parameters and it can help to reduce the parameter regions allowed by the present SNIa+CMB/BAO by about 75% when all datasets considered are combined. Thus the SL test is a worthy and long awaited measurement to probe effectively the cosmic expanding history and the properties of dark energy.