BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Sebastian Cespedes (IFT) DTSTART:20201008T140000Z DTEND:20201008T150000Z DTSTAMP:20260423T003258Z UID:IFTWeb/9 DESCRIPTION:Title: O n the time evolution of cosmological correlation functions\nby Sebasti an Cespedes (IFT) as part of IFT-Madrid Webinars\n\n\nAbstract\nDeveloping our understanding of how correlations evolve during inflation is crucial if we are to extract information about the early Universe from our late-ti me observables. To that end\, we’ll revisit the time evolution of scalar field correlators on de Sitter spacetime in the Schrodinger picture. By d irect manipulation of the Schrodinger equation\, it is possible to write down simple “equations of motion” for the coefficients which determine the wavefunction. Rather than specify a particular interaction Hamiltonia n\, we assume only very basic properties (unitarity\, de Sitter invariance and locality) to derive general consequences for the wavefunction’s evo lution. In particular\, we identify a number of “constants of motion”: properties of the initial state which are conserved by any unitary dynami cs. We further constrain the time evolution by deriving constraints from t he de Sitter isometries and show that these reduce to the familiar conform al Ward identities at late times. Finally\, we show how the evolution of a state from the conformal boundary into the bulk can be described via a nu mber of “transfer functions” which are analytic outside the horizon fo r any local interaction. These objects exhibit divergences for particular values of the scalar mass\, and we show how such divergences can be remove d by a renormalisation of the boundary wavefunction—this is equivalent t o performing a “Boundary Operator Expansion” which expresses the bulk operators in terms of regulated boundary operators. Altogether\, this impr oved understanding of the wavefunction in the bulk of de Sitter complement s recent advances from a purely boundary perspective\, and reveals new str ucture in cosmological correlators.\n LOCATION:https://researchseminars.org/talk/IFTWeb/9/ END:VEVENT END:VCALENDAR