Lorentzian wormholes in an emergent universe

A non-singular emergent universe (EU) scenario within the realm of standard Relativistic physics requires a generalization of the equation of state (EoS) connecting the pressure and energy density. This generalized EoS is capable of describing a composition of exotic matter, dark energy and cosmological dust matter. Since the EU scenario is known to violate the null energy condition (NEC), we investigate the possibility of presence of static, spherically symmetric and traversable Lorentzian wormholes in an EU. The obtained shape function is found to satisfy the criteria for wormhole formation, besides the violation of the NEC at the wormhole throat and ensuring traversability such that tidal forces are within desirable limits. Also, the wormhole is found to be stable through linear stability analysis. Most importantly, the numerical value of the EU parameter B as estimated by our wormhole model is in agreement with and lies within the range of values as constrained by observational data in a cosmological context. Also, the negative sign of the second EU parameter A as obtained from our wormhole model is in agreement with the one required for describing an EU, which further indicates on the existence of such wormholes in an EU without accounting for any additional exotic matter field or any modification to the gravitational sector.

Automated summary

A non-singular emergent universe scenario requires a generalized equation of state (EoS) to describe the composition of exotic matter, dark energy, and cosmological dust matter. This study investigates the possibility of static and traversable Lorentzian wormholes in such a scenario, which violate the null energy condition (NEC) at the throat. The obtained wormhole shape function satisfies the criteria for formation and remains stable, with the estimated EU parameters in agreement with observational data.