Speakers: Chris Byrnes, University of Sussex

The recent Planck 2015 results remain consistent with some of the simplest single-field models of inflation. Only the amplitude and scale dependence of the primordial perturbations have been detected, while there is no significant signal of non-Gaussianity, isocurvature or tensor perturbations. But does the simplicity of the data mean that the inflationary model should be equivalently simple? I will discuss the status of multifield inflation after Planck. I show that a Bayesian model comparison (which incorporates elements of Occams razor) does not disfavour the curvaton scenario relative to single-field inflation with a quadratic potential, despite having three additional free parameters.