Speaker
Paul McFadden
Description
Cosmological correlators in de Sitter spacetime exhibit infrared divergences in many cases of interest including massless and conformally coupled scalars. These divergences are due to the infinite volume of spacetime, and are analogous to the IR divergences in AdS dealt with by holographic renormalisation. In this talk, we present a renormalisation procedure for cosmological correlators in dS. We show how all tree-level IR divergences in the Schwinger-Keldysh path integral can be removed by the addition of local counterterms at the future boundary of dS. We contrast this procedure with holographic renormalisation in AdS, and discuss the implications for holography.