What if? - Exploring the Multiverse through Euclidean wormholes

TL;DR

This paper explores Euclidean wormhole solutions within the multiverse framework, analyzing their tunneling probabilities and implications for universe nucleation and inflationary evolution.

Contribution

It introduces Euclidean wormhole solutions in third quantization, modeling multiverse connections with scalar fields and calculating tunneling probabilities for universe nucleation.

Findings

Certain universes are more likely to tunnel based on energy scale bounds.

The study estimates nucleation probabilities for baby universes.

Results suggest conditions favoring inflationary evolution in the multiverse.

Abstract

We present Euclidean wormhole solutions describing possible bridges within the multiverse. The study is carried out in the framework of the third quantization. The matter content is modelled through a scalar field which supports the existence of a whole collection of universes. The instanton solutions describe Euclidean solutions that connect baby universes with asymptotically de Sitter universes. We compute the tunnelling probability of these processes. Considering the current bounds on the energy scale of inflation and assuming that all the baby universes are nucleated with the same probability, we draw some conclusions about what are the universes more likely to tunnel and therefore undergo a standard inflationary era.