Lecture notes on non-Gaussianity
  We discuss how primordial non-Gaussianity of the curvature perturbation helps
to constrain models of the early universe. Observations are consistent with
Gaussian initial conditions, compatible with the predictions of the simplest
models of inflation. Deviations are constrained to be at the sub percent level,
constraining alternative models such as those with multiple fields,
non-canonical kinetic terms or breaking the slow-roll conditions. We introduce
some of the most important models of inflation which generate non-Gaussian
perturbations and provide practical tools on how to calculate the three-point
correlation function for a popular class of non-Gaussian models. The current
state of the field is summarised and an outlook is given.
