The Planck survey satellite will constrain the statistics of the primordial density perturbation more stringently than ever before. Present observations require these statistics to be accurately Gaussian to one part in 10^3, but hint at a departure from Gaussianity slightly below this level. Analysis of Planck data will certainly dominate cosmology in the forthcoming decade, but at present we lack the technology to fully exploit information encoded in the nongaussian fraction. Moreover, if Planck confirms the presence of a microwave background bispectrum with amplitude at the level suggested by both WMAP data and probes of the three-dimensional density field, this will be sufficient to rule out the simplest and theoretically-favoured model of inflation. But there is no consensus concerning what should take its place. Instead, we should seek guidance from experiment. In this proposal I outline a tightly focused, coherent and ambitious five-year programme of research aimed at maximizing our understanding of experimental data.
In partnership with two ERC-funded postdoctoral researchers, the programme outlined in this proposal will yield four key science outcomes: first, a robust method, based on partial-wave expansions, with which to rule out microphysical models which are incompatible with observational data. Second, delivery of a precision numerical toolkit enabling the space of inflationary models and their initial conditions to be constrained by observation at an accuracy commensurate with the high-precision Planck data. Third, the ability to extract accurate predictions for observables in the case of multiple-field, non-canonical models. These are of great interest because of their status as effective field theories of ultraviolet-complete unifications of gravity with the Standard Model. Fourth, an understanding of the process by which inflationary nongaussianities can be generated, and a clear analysis of the conclusions which can be drawn from experiment.
Fields of science
Call for proposal
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