Cosmology from the 2dF QSO Redshift Survey

The 2dF QSO Redshift Survey (2QZ) is now complete and available to the astronomical community (see www.2dfquasar.org). In this paper we review some of the principle science results to come from the survey, in particular concentrating on tests for cosmological parameters. Measurements of large-scale structure using the correlation function and power spectrum, together with determinations of the geometric distortion of clustering in redshift-space have been used. These produce a consistent picture which is well matched to the now standard cosmological model with \omm≃0.3 and \oml≃0.7. In particular, geometric distortions provide evidence for non-zero \oml independent of type Ia supernovae, the CMB, or the assumed type of dark matter (e.g. CDM). However, gravitational lensing results in the form of potential arcminute separation lensed pairs and a stronger than expected anti-correlation between QSOs and foreground galaxies in groups and clusters may prove to be inconsistent with the current standard model. These issues certainly require further investigation.