Lorentz-violating wormholes: The role of the matter coupled to Lorentz-violating fields

TL;DR

This paper explores how matter coupled to Lorentz-violating fields can enable the formation of traversable wormholes, analyzing their properties and scalar wave perturbations across different Lorentz-violating scenarios.

Contribution

It introduces novel couplings in the Lagrangian that facilitate wormhole solutions in Lorentz-violating theories and examines their perturbation spectra using multiple computational methods.

Findings

Lorentz-violating couplings enable traversable wormholes.

Scalar perturbations can mimic General Relativity dynamics.

Strong agreement among different quasinormal mode computation methods.

Abstract

The anisotropies induced by Lorentz-violating fields pose significant challenges for the search for compact objects in non-vacuum environments. In this work, we demonstrate that introducing couplings between Lorentz-violating fields and matter facilitates the formation of traversable wormholes. Specifically, we introduce additional couplings in the Lagrangian of a phantom scalar field and derive Ellis-Bronnikov spacetime analogs in three distinct Lorentz-violating scenarios: (I) modifications arising from the vacuum expectation value of the bumblebee field, (II) contributions from the vacuum expectation value of an antisymmetric rank-2 tensor field, and (III) a combined scenario incorporating both fields. In the latter case, despite the distinct nature of the fields, their non-zero vacuum expectation values contribute additively to the overall effect on the phantom distribution and on the resulting line element. Moreover, we consider scalar waves to probe the effects of the Lorentz violation in these spacetimes. Notably, the additional Lorentz-violating couplings can alter scalar field dynamics such that perturbations propagate as if in a General Relativity background, which allows for some traits of Lorentz violation to be hidden. We compute the quasinormal mode spectra of these perturbations using three methods: direct integration, 6th-order WKB approximation, and the Prony method, finding strong agreement among the results.