Primordial Black Holes in non-linear perturbation theory

Understand

This thesis begins with a study of the origin of cosmological fluctuations with special attention to those cases in which the non-Gaussian correlation functions are large.

• The analysis shows that perturbations from an almost massless auxiliary field generically produce large values of the non-linear parameter f_NL.
• The effects of including non-Gaussian correlation functions in the statistics of cosmological structure are explored by constructing a non-Gaussian probability distribution function (PDF).
• Such PDF is derived for the comoving curvature perturbation from first principles in the context of quantum field theory, with n-point correlation functions as the only input.