Seminarium Kosmologia i Fizyka Cząstek

We discuss multi-field models of inflation, particularly focusing on mixed inflaton and spectator field models where the inflaton and the spectator fields can be both responsible for primordial density fluctuations. First we discuss the formalism to investigate such models and current constraints from CMB, then we investigate the CMB spectral μ distortion in the model. We argue that future observations of μ distortion could provide a critical test of models of this kind. We also discuss the implications of such small scale observations on the running of the primordial spectrum. Some other probes such as 21 cm line fluctuations are also discussed.