Title: Quantum Diffusion During Cosmic Inflation
Abstract: When primordial inhomogeneities are produced with sufficiently large amplitude in the early universe, they may subsequently collapse into primordial black holes. I will explain why the effect of quantum diffusion during inflation needs to be taken into account in such a case, and how the statistics of cosmological fluctuations can be predicted within the formalism of stochastic inflation. In particular, I will show that quantum diffusion leads to a type of non-Gaussianity that cannot be captured by perturbative parametrisations, and which leaves specific imprints on the statistics of collapsed structures that I will discuss.