Traversable double-throat wormholes in a string cloud background

TL;DR

This paper introduces a new class of traversable double-throat wormholes in a string cloud background, analyzing their geometric properties, energy conditions, and the localization of exotic matter.

Contribution

It constructs and analyzes double-throat wormhole solutions with a string cloud background, highlighting their geometric features and matter distribution.

Findings

Double-throat structures emerge as a perturbation of Ellis-Bronnikov metric.

Energy density approaches a positive constant at the center.

Exotic matter is localized near the throats, with non-exotic matter supporting the inter-throat region.

Abstract

This work constructs a new class of traversable wormhole solutions with a double-throat topology, modeled as a localized perturbation of the Ellis-Bronnikov metric in a string cloud background. Embedding diagrams and the analysis of curvature invariants, including the Kretschmann scalar and the Weyl invariant, illustrate the geometric transition from single to double-throat structures as a function of the perturbation amplitude. By imposing the zero-tidal condition, we derive analytical expressions for the energy density and pressures, showing an asymptotic $r^{-2}$ decay characteristic of a string cloud, endowed with the topology of a global monopole. A key finding is that the energy density converges to a positive constant at the center, with the radial pressure becoming negative. This local behavior provides the repulsive support necessary to inflate the inter-throat region with non-exotic matter, concentrating Null Energy Condition violations to the throat vicinities. These results suggest that multi-throat geometries offer a natural mechanism for localizing exotic matter while maintaining a physical asymptotic background.