Wormhole spacetimes in an expanding universe: Energy conditions and future singularities
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866914255919382528 |
|---|---|
| author | Katsuragawa, Taishi Nojiri, Shin'ichi Odintsov, Sergei D. |
| author_facet | Katsuragawa, Taishi Nojiri, Shin'ichi Odintsov, Sergei D. |
| contents | We study wormhole geometries embedded in an expanding universe within a four-scalar non-linear $σ$ model, where the target-space metric is identified with the spacetime Ricci tensor. In this framework, wormholes can remain stable even when conventional energy conditions are violated. However, once cosmological expansion is included, the effective energy density and pressure are modified by the cosmological fluid, enabling the energy conditions to be satisfied. We further present intriguing geometries in which a finite future singularity appears in our universe but not in another universe connected by the wormhole. Near the throat, the hypersurface becomes timelike, allowing trajectories to traverse to the other universe before the singularity and return afterwards. We also construct wormhole solutions motivated by galactic dark-matter halo profiles, where the required non-vanishing pressure arises naturally from the four-scalar non-linear $σ$ model. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2511_03275 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Wormhole spacetimes in an expanding universe: Energy conditions and future singularities Katsuragawa, Taishi Nojiri, Shin'ichi Odintsov, Sergei D. General Relativity and Quantum Cosmology High Energy Physics - Theory We study wormhole geometries embedded in an expanding universe within a four-scalar non-linear $σ$ model, where the target-space metric is identified with the spacetime Ricci tensor. In this framework, wormholes can remain stable even when conventional energy conditions are violated. However, once cosmological expansion is included, the effective energy density and pressure are modified by the cosmological fluid, enabling the energy conditions to be satisfied. We further present intriguing geometries in which a finite future singularity appears in our universe but not in another universe connected by the wormhole. Near the throat, the hypersurface becomes timelike, allowing trajectories to traverse to the other universe before the singularity and return afterwards. We also construct wormhole solutions motivated by galactic dark-matter halo profiles, where the required non-vanishing pressure arises naturally from the four-scalar non-linear $σ$ model. |
| title | Wormhole spacetimes in an expanding universe: Energy conditions and future singularities |
| topic | General Relativity and Quantum Cosmology High Energy Physics - Theory |
| url | https://arxiv.org/abs/2511.03275 |