Neutron star cooling in modified gravity theories
Neutron star cooling in modified gravity theories
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DOI：
10.1093/ptep/ptab099
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发表时间：
2020-03
期刊：
影响因子：
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通讯作者：
Akira Dohi;R. Kase;Rampei Kimura;Kazuhiro Yamamoto;M. Hashimoto
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文献类型：
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作者：
Akira Dohi;R. Kase;Rampei Kimura;Kazuhiro Yamamoto;M. Hashimoto
首次用标量-张量理论研究孤立中子星的热演化。从孤立中子星的温度观测角度看，是否发生直接的乌尔卡过程导致的快速冷却是一个有趣的问题。冷却效果通常受质子分数和中心密度的影响。如果由于引力的改变而产生第五种力，中子星的中心密度和质量之间的关系就不同于广义相对论中的中子星密度和质量之间的关系，冷却曲线也天真地被认为是不同的。我们发现，中子星表面附近未屏蔽的第五力改变了质量-中心密度关系，即使对于质量较小的中子星，也可以触发直接的乌尔卡过程。这可能使我们能够用中子星冷却来检验引力理论。
We study thermal evolution of isolated neutron stars in scalar-tensor theories for the first time. Whether the rapid cooling due to the direct Urca process occurs or not is an interesting question in the viewpoint of the temperature observation of isolated neutron stars. The cooling effect is typically influenced by the proton fraction and the central density. If a fifth force is mediated due to modification of gravity, the relation between the central density and mass of neutron stars differs from one in general relativity, and the cooling curve is also naively expected to be varied. We find that an unscreened fifth force near the surface of neutron stars changes mass-central density relation, and the direct Urca process can be triggered even for neutron stars with smaller mass. This might enable us to test gravitational theories with neutron star cooling.