Higher-Dimensional Bulk Wormholes and their Manifestations in Brane Worlds

TL;DR

This paper explores how higher-dimensional bulk wormholes in anti-de Sitter spaces could influence our universe, potentially manifesting as observable wormholes and leading to the formation of baby universes.

Contribution

It introduces a model linking micro branes and exotic matter in higher dimensions to the emergence of macroscopic wormholes and baby universes in brane world scenarios.

Findings

Micro branes can act as exotic matter supporting wormholes

Bulk wormholes may manifest as observable wormholes in our universe

Potential formation of baby universes from bulk wormhole dynamics

Abstract

There is nothing to prevent a higher-dimensional anti-de Sitter bulk spacetime from containing various other branes in addition to hosting our universe, presumed to be a positive-tension 3-brane. In particular, it could contain closed, microscopic branes that form the boundary surfaces of void bubbles and thus violate the null energy condition in the bulk. The possible existence of such micro branes can be investigated by considering the properties of the ground state of a pseudo-Wheeler-DeWitt equation describing brane quantum dynamics in minisuperspace. If they exist, a concentration of these micro branes could act as a fluid of exotic matter able to support macroscopic wormholes connecting otherwise distant regions of the bulk. Were the brane constituting our universe to expand into a region of the bulk containing such higher-dimensional macroscopic wormholes, they would likely manifest themselves in our brane as wormholes of normal dimensionality, whose spontaneous appearance and general dynamics would seem inexplicably peculiar. This encounter could also result in the formation of baby universes of a particular type.