Bra-ket wormholes in gravitationally prepared states

Abstract: We will discuss two-dimensional toy-models of inflation in which the state of the universe is prepared by a gravitational path integral. As a first model, we consider a state produced by Euclidean AdS_2 evolution followed by flat space evolution. We use the fine grained entropy formula to explore the nature of the state. We find that the naive hyperbolic space geometry (analog of the Hartle-Hawking state) leads to a paradox. This is solved if we include a geometry that connects the bra with the ket, a bra-ket wormhole. The semiclassical Lorentzian interpretation leads to CFT state entangled with an expanding and collapsing Friedmann cosmology. I will then describe a similar model where the state is prepared by the dS_2 evolution and highlight related puzzles.

general relativity and quantum cosmologyHEP - phenomenologyHEP - theorymathematical physics

Audience: researchers in the topic

CCTP HEP Seminars

Series comments: Description: Seminars in high energy physics

Weekly HEP Seminars in the broad spectrum of High Energy Physics at University of Crete.

Recordings of past seminars can be found at conference.physics.uoc.gr/b/hep-kzk-2ad