Dark energy, relativistic effects in cosmological observations.
The world’s largest astronomy experiment, the Square Kilometre Array (SKA) is currently being built in South Africa and Australia. This giant radio telescope array will look deeper into the Universe and further back in time than any other telescope before it. I am currently based mainly in South Africa, where I hold an SKA Research Chair that supports me and a team of postgraduate and postdoctoral researchers working on cosmology with the SKA. This team has a strong collaboration with the ICG in Portsmouth. The SKA and its precursors will provide the biggest ever maps of the distribution of galaxies in the Universe. With these maps, we will be able to find out more about one of the greatest puzzles in modern physics – what is the nature of the Dark Energy that is forcing the Universe to expand faster and faster? Our model of the Universe is based on Einstein’s 1915 theory of General Relativity. This theory has been very successful in unlocking the secrets of the vast and ancient Universe. But perhaps Dark Energy does not exist – and instead, the acceleration of the Universe signals a breakdown of Einstein’s theory on very large scales? The SKA, together with major surveys on optical telescopes, will help us to answer this question. Portsmouth is a world-leader in galaxy surveys using optical telescopes, and we have the exciting opportunity to develop this further via the SKA.