Here, we review the most recent progress in our understanding of quantum mechanical
observables in cosmology in the perturbative regime. It relies on an approach that considers …

A bstract Scattering amplitudes at weak coupling are highly constrained by Lorentz
invariance, locality and unitarity, and depend on model details only through coupling …

We extend the cosmological bootstrap to correlators involving massless particles with spin.
In de Sitter space, these correlators are constrained both by symmetries and by locality. In …

A bstract We study the imprints of massive particles with spin on cosmological correlators.
Using the framework of the effective field theory of inflation, we classify the couplings of …

A bstract We obtain solutions of the Wheeler-DeWitt equation with positive cosmological
constant for a closed universe in the large-volume limit. We argue that this space of solutions …

A bstract Develo** our understanding of how correlations evolve during inflation is crucial
if we are to extract information about the early Universe from our late-time observables. To …

A bstract It is well-known that the primordial scalar curvature and tensor perturbations, ζ and
γ ij, are conserved on super-horizon scales in minimal inflation models. However, their wave …

A bstract The representation theory of de Sitter space allows for a category of partially
massless particles which have no flat space analog, but could have existed during inflation …

These lecture notes provide an overview of different aspects of de Sitter space and their
plausible holographic interpretations. We start with a general description of the classical …

If the graviton is the only high spin particle present during inflation, then the form of the
observable tensor three-point function is fixed by de Sitter symmetry at leading order in slow …