Observational Signatures of Accelerating Universes

Motivated by recent advances in observational cosmology, we propose a broad and unified programme of theoretical research into the nature of accelerating universes. We will continue and further develop our work on inflationary cosmology, with particular emphasis on establishing observable signatures of the scenario. We will focus on the generation of non-Gaussian density perturbations in a number of theoretically well-motivated classes of single- and multiple-field models. Mechanisms for explaining the present-day accelerated expansion of the universe and for testing the Friedmann equation on large scales will be explored and developed within the context of modified gravity theories. This proposal will continue our present theoretical work in these topics supported by PPARC. Ultimately, such a programme will yield unique information on the origin, evolution and large-scale structure of the universe, thereby overlapping significantly with key areas of astronomy and particle physics as covered by the PPARC Road Map and emphasized by the Science Committee Strategy document.