Entanglement in the cosmological patch of de Sitter and Inflation

It has long been debated whether cosmic inflation imprints any quantum signatures on the primordial curvature perturbations. In this talk, I’ll summarize how we can analyze this question using modern tools from relativistic quantum information, specifically based on subalgebras of local observables. Using these tools, I’ll compare the entanglement of a free, massive scalar field in the Bunch-Davies vacuum in the cosmological patch of de Sitter spacetime with that in Minkowski spacetime. Interestingly, there is less entanglement between spatially localized field modes in de Sitter, despite existing more entanglement stored globally in the field. This shows that inflation does not produce entanglement between accessible observables.