| 摘要: |
| 虫洞是设想中连接遥远时空区域的隧道.在广义相对论中，虫洞只能由违反能量条件的奇异物质支持.而本研究考虑在挠率-物质非最小耦合的f(T)引力中，由非奇异的物质支持的虫洞.研究发现，挠率与物质的非最小耦合确实能支撑虫洞的打开.然而，就几何角度而言，为使虫洞时空渐进平坦，耦合的物质密度必须在大半径处迅速衰减.否则在有限远处，或是度规变号,或是虫洞无法有效嵌入于四维欧氏空间，这些都会导致虫洞只有有限大小.另-方面，支撑虫洞的物质源只在喉的某个邻域内满足类光能量条件.因此，当前模型中的虫洞只有有限大小，无法扩展到整个时空. |
| 关键词: f(T)引力 虫洞 非最小耦合 能量条件 |
| DOI：10.3969/J.ISSN.1000-5137.2023.05.001 |
| 分类号:O 412.1 |
| 基金项目:The National Natural Science Foundation of China (12105179) |
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| Wormholes without exotic matter in nonminimal torsion-matter coupling f（T） gravity |
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YANG Jing, LIN Ruihui, ZHAI Xianghua
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Mathematics and Science College, Shanghai Normal University, Shanghai 200234, China
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| Abstract: |
| Wormholes are hypothetical tunnels that connect remote parts of spacetime. In General Relativity, wormholes are threaded by exotic matter that violates the energy conditions. In this work, we consider wormholes threaded by nonexotic matter in nonminimal torsion-matter coupling $f(T)$ gravity. We find that the nonminimal torsion-matter coupling can indeed hold the wormhole open. However, from geometric point of view, for the wormhole to have asymptotic flatness, the coupling matter density must falloff rapidly at large radius, otherwise the physical wormhole must be finite due to either change of metric signature or lack of valid embedding. On the other hand, the matter source supporting the wormhole can satisfy the null energy condition only in the neighborhood of the throat of the wormhole. Therefore, the wormhole in the underlying model has finite sizes and cannot stretch to the entire spacetime. |
| Key words: $f(T)$ gravity wormhole nonminimal coupling energy conditions |
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