Birth of Inflationary Universes via Wineglass Wormholes and their No-Boundary Relatives

TL;DR

This paper explores Euclidean wineglass wormholes that facilitate the nucleation of inflationary universes, presenting explicit solutions supported by various fields and analyzing topology-changing transitions with implications for cosmology.

Contribution

It introduces explicit numerical solutions for wineglass wormholes supported by axionic or magnetic fields and examines their topology-changing transitions and relation to no-boundary instantons.

Findings

Explicit numerical wormhole solutions supported by axionic or magnetic fields.

Identification of topology-changing transitions in wormhole solutions.

Connection between small charge limits and no-boundary instantons.

Abstract

We study Euclidean wineglass wormholes, which mediate the nucleation of inflationary spacetimes from an existing spacetime with asymptotically flat or Anti-de Sitter regions. These wormholes are distinguished by the presence of a local maximum of the scale factor, which allows the analytically continued Lorentzian spacetime to expand after materialization. We present explicit numerical wormhole solutions supported either by an axionic field or a magnetic gauge field, in both cases in conjunction with a self-interacting scalar field. More exotic solutions, with multiple extrema of the scale factor, are also described. As we discovered recently, in the limit of small axionic or magnetic charge, wineglass wormhole solutions split into two separate geometries, one being the background spacetime and the other a disconnected no-boundary instanton. We study the associated topology changing transition in detail and provide an extensive discussion of both the properties and puzzles exhibited by this common family of wineglass/no-boundary instantons.