Cosmological wormholes

TL;DR

This paper defines and explores dynamical cosmological wormholes, presenting numerical and analytical solutions that connect multiple universes without trapping horizons, challenging static energy condition assumptions.

Contribution

It introduces a new definition for dynamical wormholes and provides explicit solutions connecting Friedmann universes, expanding understanding of wormhole physics in cosmology.

Findings

Dynamical wormholes can satisfy null energy conditions.

Numerical solutions connect multiple asymptotic regions.

Analytic solutions demonstrate wormholes without trapping horizons.

Abstract

Motivated by the cosmological wormhole solutions obtained from our recent numerical investigations, we provide a definition of a wormhole which applies to dynamical situations. Our numerical solutions do not have timelike trapping horizons but they are wormholes in the sense that they connect two or more asymptotic regions. Although the null energy condition must be violated for static wormholes, we find that it can still be satisfied in the dynamical context. Two analytic solutions for a cosmological wormhole connecting two Friedmann universes without trapping horizons are presented.