Cosmology with the 6-degree field galaxy survey

[Truncated abstract] This thesis presents the analysis of the clustering of galaxies in the 6dF Galaxy Survey (6dFGS). At large separation scales the baryon acoustic oscillation (BAO) signal is detected which allows a measurement of the distance ratio, rs(zd)=DV (zeff) = 0:336±0:015 (4:5% precision), where rs(zd) is the sound horizon at the drag epoch zd and DV (zeff) is the absolute distance to the effective redshift of the survey, given by zeff = 0:106. The low effective redshift of 6dFGS makes it a competitive and independent alternative to Cepheids and low-z supernovae in constraining the Hubble constant. The value of the Hubble constant reported in this work is H0 = 67:0±3:2 km s¹ Mpc±¹ (4:8% precision) which depends only on the WMAP-7 calibration of the sound horizon and on the galaxy clustering in 6dFGS. Compared to earlier BAO studies at higher redshift, this analysis is less dependent on other cosmological parameters. This thesis also includes forecasts for the proposed TAIPAN all-southern-sky optical galaxy survey and the radio WALLABY survey. TAIPAN has the potential to constrain the Hubble constant with 3% precision using the BAO technique...