Maartens, RoyKopana, Mponeng2021-02-252024-10-302021-02-252024-10-302020https://hdl.handle.net/10566/16622>Magister Scientiae - MScThe new 64-dish radio telescope array MeerKAT will be absorbed into the international Square Kilometre Array (SKA) in late 2020s. These two telescope arrays will produce three-dimensional maps of the integrated intensity of the 21cm emission from neutral hydrogen in galaxies, out to redshifts of 1:5 and 3 respectively. These maps contain a signature of the growth of large-scale structure in the Universe. This signature can be uncovered via redshift space distortions of the two-point correlation function, or power spectrum, of the 21cm brightness temperature uctuations. The growth rate governs the amplitude of the anisotropic signal from redshift-space distortions. It is a powerful probe of gravity and its measurement has the potential to test whether general relativity holds. We use models of the 21cm intensity and its power spectrum, starting from a simple linear model of redshift-space distortions and then extending to nonlinear models. With these models, we make Fisher forecast predictions of the precision with which MeerKAT and the SKA can measure the growth rateenMeerKATSouth AfricaTelescopeSquare Kilometre ArrayUniversity of the Western Cape