Scheme: Wolfson Research Merit Awards
Organisation: University of Edinburgh
Dates: May 2015-Apr 2020
Summary: One of the biggest mysteries in Cosmology is explaining why the expansion of the Universe is accelerating. This acceleration implies that a new force of nature is at work, beyond the four known fundamental forces. We do not yet know what this new force is, and so we call it Dark Energy. A candidate for the Dark Energy is Einstein’s anti-gravity cosmological constant, but basic quantum theory predicts huge contributions to this from fluctuations in the vacuum. With no obvious solution in sight we are compelled to radically re-think our view of the fundamental nature of reality, and to entertain proposals which include extra spatial dimensions and multiple universes. Without a clear resolution to this problem, cosmologists have developed a wide variety of possible low-energy limits to a more fundamental explanation of the acceleration, which themselves predict new forces and changes in the nature of gravity. These low-energy predictions can be tested through observations of the expansion history and the growth of structure in the Universe. We now need highly accurate observations to distinguish between these low-energy alternatives, and point the way towards a more fundamental theory. My research is to develop and explore the theoretical models of Dark Energy, and to detect and measure the subtle observational signatures which will discriminate between them. Over the next few years new astronomical instruments will undertake vast surveys of the Universe to address the issue of Dark Energy to unprecedented accuracy, producing high-resolution images of billions of galaxies over most of the sky and across most of the Universe. These images will be analysed to extract the information we need about Dark Energy, to reveal its true nature and discover what that implies about our Universe.