Perturbations in higher derivative gravity beyond maximally symmetric spacetimes
Perturbations in higher derivative gravity beyond maximally symmetric spacetimes
复制标题
超出最大对称时空的高导数引力扰动
作者：
K. Kumar;Shubham Maheshwari;A. Mazumdar
我们研究无限导数引力(IDG)的(协变)标量矢量张量(SVT)扰动，在作用量的二次水平上，围绕共形平坦的协变常曲率背景，这些背景不是最大对称的时空(MSS)。这扩展了之前对MSS周围的扰动所做的分析，这些扰动被证明是无鬼影的。我们激发了我们对背景的选择，这些背景作为IDG在UV中的解决方案出现，避免了大爆炸和黑洞奇点。与MSS相反，本文证明了所有的SVT模式在作用量的二次水平上是相互耦合的。我们考虑了完整的IDG作用的简单例子，并说明了这种混合以及作用可以对角化和构造无鬼解的情况。我们的研究广泛适用于非奇异宇宙学和背景偏离MSS的黑洞物理。在附录中，我们提供了在共形平坦和任意背景下的SVT摄动，这些摄动可以作为研究各种高阶导数重力模型的SVT摄动的有用结果的概要。
We study (covariant) scalar-vector-tensor (SVT) perturbations of infinite derivative gravity (IDG), at the quadratic level of the action, around conformally-flat, covariantly constant curvature backgrounds which are not maximally symmetric spacetimes (MSS). This extends a previous analysis of perturbations done around MSS, which were shown to be ghost-free. We motivate our choice of backgrounds which arise as solutions of IDG in the UV, avoiding big bang and black hole singularities. Contrary to MSS, in this paper we show that, generically, all SVT modes are coupled to each other at the quadratic level of the action. We consider simple examples of the full IDG action, and illustrate this mixing and also a case where the action can be diagonalized and ghost-free solutions constructed. Our study is widely applicable for both non-singular cosmology and black hole physics where backgrounds depart from MSS. In appendices, we provide SVT perturbations around conformally-flat and arbitrary backgrounds which can serve as a compendium of useful results when studying SVT perturbations of various higher derivative gravity models.
影响因子：
2.1
作者：
Duncan A. Brown;K. Vahi;M. Taufer;Von Welch;E. Deelman;Lorena A. Barba;George K. Thiruvathukal
通讯作者：
Duncan A. Brown;K. Vahi;M. Taufer;Von Welch;E. Deelman;Lorena A. Barba;George K. Thiruvathukal
影响因子：
8.6
作者：
Abbott, B. P.;Abbott, R.;Zweizig, J.
通讯作者：
Zweizig, J.