Extraction of Cosmological Information from WiggleZ

Abstract

In this thesis, I analyse the 2D anisotropic Baryon Acoustic Oscillation (BAO) signal present in the final WiggleZ dataset. I utilise newly released covariance matrices from the WizCOLA simulations and follow well tested methodologies used in prior analyses of the BAO signal in alternative datasets. The WiggleZ data is presented in two forms - in multipole expansion and in data wedges - both of which are analysed in this thesis. I test my model against previous one dimensional analyses of the BAO signal in the WiggleZ data and against WizCOLA simulations, and find it to be free of bias or systematic offsets. However, the analysis on the wedge data format was unable to properly constrain cosmological parameters, and thus discarded in favour of the multipole analysis. The multipole analysis determined \(\Omega_c h^2\), \(H(z)\) and \(D_A(z)\) for three redshift bins, of effective redshifts \(z = 0.44, 0.60\) and \(0.73\). The respective constraints on \(\Omega_c h^2\) are \(0.119^{+0.029}_{-0.026}\), \(0.151^{+0.038}_{-0.025}\) and \(0.140^{+0.036}_{-0.022}\). The fits for \(H(z)\) are respectively \(87 \pm 16\), \(90 \pm 15\) and \(82 \pm 13\) km s\(^{-1}\) Mpc\(^{-1}\), and for \(D_A(z)\) I find values of \(1300 \pm 160\), \(1300 \pm 180\) and \(1350 \pm 160\) Mpc. These cosmological constraints are consistent with Flat \(\Lambda\)CDM cosmology.