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In this thesis, we show how the structure of the landscape potential of theprimordial Universe may be probed through the primordial density perturbationsresponsible for the origin of the cosmic microwave background anisotropies andthe large-scale structure of our Universe. Isocurvature fields may havefluctuated across the barriers separating local minima of the landscapepotential during inflation. We analyze how this process could have impacted theevolution of the primordial curvature perturbations. If the typical distanceseparating consecutive minima of the landscape potential and the height of thepotential barriers are smaller than the Hubble expansion rate parametrizinginflation, the probability distribution function of isocurvature fields becomesnon-Gaussian due to the appearance of bumps and dips associated with thestructure of the potential. We show that this non-Gaussianity can betransferred to the statistics of primordial curvature perturbations. The typeof non-Gaussian structure that emerges in the distribution of curvatureperturbations cannot be fully probed with the standard methods of polyspectra;instead, the probability distribution function is needed.  To substantiate our claims, we offer a concrete model consisting of anisocurvature perturbation with a sinusoidal potential and a linear derivativecoupling between the isocurvature and curvature field. This result isgeneralized to arbitrary potentials and briefly studied beyond first-orderperturbation theory. Finally, we undertake a study of primordialnon-Gaussianity of the local type, where we use our results to reconstruct andconstrain the shape of the landscape potential with the help of CosmicMicrowave Background observations by the Planck telescope and explore prospectsfor observable quantities in the Large-Scale Structure of our universe towardsconstraining its primordial statistics.

Revealing the Structure of the Inflationary Landscape through Primordial non-Gaussianity