Black holes in a type-II minimally modified gravity
Black holes in a type-II minimally modified gravity
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DOI：
10.1088/1475-7516/2021/03/004
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发表时间：
2020-10
影响因子：
6.4
通讯作者：
Antonio De Felice;and J D Doll;F. Larrouturou;S. Mukohyama
中科院分区：
文献类型：
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作者：
Antonio De Felice;and J D Doll;F. Larrouturou;S. Mukohyama
在最近提出的ii型最小修正引力理论的背景下，即具有两个局部物理自由度的度量引力理论，不具有爱因斯坦坐标系，我们研究了球对称真空解来探索强引力区。尽管在重力部分没有额外的自由度，真空解在局部上与Schwarzschild或Schwarzschild-(A)dS度规不同，因此Birkhoff定理不成立。一般解由几个自由的时间函数参数化，并允许正则的捕获和事件视界。根据时间自由函数的选择，真空中零收敛条件可能被违反。即使在静态极限下，当该极限下的解简化为史瓦西或史瓦西-(A)dS解时，从解中推导出的有效宇宙学常数通常与由作用决定的宇宙学值不同。然而，一旦施加了一组合适的渐近条件，使得解在相应的宇宙学设置中表示紧致物体，则恢复了标准史瓦西或史瓦西-(a)dS度规，并且有效宇宙学常数与从作用推断的值一致。
In the context of the recently proposed type-II minimally modified gravity theory, i.e. a metric theory of gravity with two local physical degrees of freedom that does not possess an Einstein frame, we study spherically symmetric vacuum solutions to explore the strong gravity regime. Despite the absence of extra degrees of freedom in the gravity sector, the vacuum solutions are locally different from the Schwarzschild or Schwarzschild-(A)dS metric in general and thus the Birkhoff theorem does not hold. The general solutions are parameterized by several free functions of time and admit regular trapping and event horizons. Depending on the choice of the free functions of time, the null convergence condition may be violated in vacuum. Even in the static limit, while the solutions in this limit reduce to the Schwarzschild or Schwarzschild-(A)dS solutions, the effective cosmological constant deduced from the solutions is in general different from the cosmological value that is determined by the action. Nonetheless, once a set of suitable asymptotic conditions is imposed so that the solutions represent compact objects in the corresponding cosmological setup, the standard Schwarzschild or Schwarzschild-(A)dS metric is recovered and the effective cosmological constant agrees with the value inferred from the action.