Document Type
Article
Publication Date
8-7-2024
Abstract
It has been proven that in standard Einstein gravity, exotic matter (i.e., matter violating the pointwise and averaged Weak and Null Energy Conditions) is required to stabilize traversable wormholes. Quantum field theory permits these violations due to the quantum coherent effects found in any quantum field. Even reasonable classical scalar fields violate the energy conditions. In the case of the Casimir effect and squeezed vacuum states, these violations have been experimentally proven. It is advantageous to investigate methods to minimize the use of exotic matter. One such area of interest is extended theories of Einstein gravity. It has been claimed that in some extended theories, stable traversable wormholes solutions can be found without the use of exotic matter. There are many extended theories of gravity, and in this review paper, we first explore đ(đ ) theories and then explore some wormhole solutions in đ(đ ) theories, including Lovelock gravity and Einstein Dilaton GaussâBonnet (EdGB) gravity. For completeness, we have also reviewed âOther wormholesâ such as Casimir wormholes, dark matter halo wormholes, thin-shell wormholes, and Nonlocal Gravity (NLG) wormholes, where alternative techniques are used to either avoid or reduce the amount of exotic matter that is required.
Recommended Citation
Radhakrishnan, Ramesh, Patrick Brown, Jacob Matulevich, Eric Davis, Delaram Mirfendereski, and Gerald Cleaver. "A Review of Stable, Traversable Wormholes in f (R) Gravity Theories." Symmetry 16, no. 8 (2024): 1007. https://doi.org/10.3390/sym16081007
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Publication Title
Symmetry
DOI
https://doi.org/10.3390/sym16081007
Comments
Š 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).