Inflationary gravitational waves in the effective field theory of modified gravity
Inflationary gravitational waves in the effective field theory of modified gravity
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DOI：
10.1103/physrevd.91.103506
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发表时间：
2014-11
影响因子：
5
通讯作者：
A. D. Felice;S. Tsujikawa
中科院分区：
文献类型：
--
作者：
A. D. Felice;S. Tsujikawa
在修正引力的有效场论方法中，我们导出了平坦各向同性宇宙学背景下张量微扰的二阶作用量和运动方程。这种分析适应了广泛的引力理论，包括Horndeski理论，它的推广，以及空间导数高于二阶的理论（例如，Horava-Lifshitz引力）。通过考虑高阶空间导数引起的修正和对de Sitter背景的慢滚修正，我们得到了张量模的暴胀功率谱。我们还表明，在具体的修改引力理论的领导阶谱可以映射到广义相对论下的非形式变换。我们的一般公式将有助于限制暴胀模型未来对宇宙微波背景中B模式极化的精确测量。
In the approach of the effective field theory of modified gravity, we derive the second-order action and the equation of motion for tensor perturbations on the flat isotropic cosmological background. This analysis accommodates a wide range of gravitational theories including Horndeski theories, its generalization, and the theories with spatial derivatives higher than second order (e.g., Horava-Lifshitz gravity). We obtain the inflationary power spectrum of tensor modes by taking into account corrections induced by higher-order spatial derivatives and slow-roll corrections to the de Sitter background. We also show that the leading-order spectrum in concrete modified gravitational theories can be mapped on to that in General Relativity under a disformal transformation. Our general formula will be useful to constrain inflationary models from the future precise measurement of the B-mode polarization in the cosmic microwave background.