Baby Universes born from the Void

Abstract

We propose a novel construction of a third quantised baby universe Hilbert space ${\mathcal{H}}_{BU}$ for the quantum gravity path integral. In contrast to the original description of $\alpha$-parameters, both the bulk and boundary microscopic parameters are fixed in our proposal. Wormholes and baby universes appear due to refined observables, of the boundary dual quantum field theories, that crucially involve the space of representations of the gauge group. Irreducible representations, on which the path integral factorises, give rise to field theoretic superselection sectors and replace the $\alpha$ states.

10 pages; Extended version of the essay that received an Honourable Mention in the Gravity Research Foundation 2022 Awards for Essays on Gravitation; v2 - Added reference and minor clarifications

References in corpus (6)

• Symmetries and Strings in Field Theory and Gravity
• T-Branes and Monodromy
• On gravitational description of Wilson lines
• Euclidean Wormholes in String Theory
• Euclidean Wormholes and Holography
• On completeness and generalized symmetries in quantum field theory

Cited by in corpus (1)

• Notes on Wormhole Cancellation and Factorization