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arXiv 2007.01968gr-qcastro-ph.HEnucl-th
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广义Rastall引力及其对致密天体的影响

Generalized Rastall's gravity and its effects on compact objects

Clésio E. Mota, Luis C. N. Santos, Franciele M. da Silva, Guilherme Grams, Iarley P. Lobo, Débora P. Menezes

摘要:

本文给出了Rastall引力的一个推广,它改变了能量动量张量的守恒定律,从而使能量动量张量的迹与Ricci标量一起被考虑在协变导数的表达式中.然后,我们得到了该理论中的场方程,并在球对称时空中求解了它们。我们证明了在广义Rastall引力的真空中,外解有两类可能的球对称解,并对其中一类进行了详细的分析。与广义相对论中的常数值$k=8πG$不同,广义相对论中的引力参数$k$取决于拉斯特尔常数$α$。作为一个应用,我们使用现实状态方程(EoS)作为输入,仔细分析了理论对中子星的影响。结果表明,在两个代表性的EoS内,中子星的轮廓存在重要差异。

英文摘要:

We present a generalization of Rastall's gravity in which the conservation law of the energy-momentum tensor is altered, and as a result, the trace of the energy-momentum tensor is taken into account together with the Ricci scalar in the expression for the covariant derivative. Afterwards, we obtain the field equations in this theory and solve them by considering a spherically symmetric space-time. We show that the external solution has two possible classes of solutions with spherical symmetry in the vacuum in generalized Rastall's gravity, and we analyse one of them explicitly. The generalization, in contrast to constant value $k=8πG$ in general relativity, has a gravitational parameter $k$ that depends on the Rastall constant $α$. As an application, we perform a careful analysis of the effects of the theory on neutron stars using realistic equations of state (EoS) as input. Our results show that important differences on the profile of neutron stars are obtained within two representatives EoS.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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