Removing Ostrogradski's ghost from cosmological perturbations in f(R,R_{mu nu}^2,C_{mu nu rho sigma}^2) gravity
Removing Ostrogradski's ghost from cosmological perturbations in f(R,R_{mu nu}^2,C_{mu nu rho sigma}^2) gravity
复制标题
从 f(R,R_{mu nu}^2,C_{mu nu rho sigma}^2) 引力中的宇宙扰动中消除奥斯特罗格拉茨基幽灵
DOI：
10.1142/s021773231650067x
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Tsutomu Kobayashi
中科院分区：
文献类型：
--
作者：
Yuji Akita;Tsutomu Kobayashi
最近，有人认为，通过以洛伦兹破坏的方式向理论添加约束，可以稳定里奇张量平方的引力。迄今为止，明可夫斯基/德西特背景的波动已经证明了这一点。我们证明，同样的方案对于消除通用型引力理论中宇宙学背景波动中的奥斯特罗格拉茨基幽灵同样有效。作为应用，我们从稳定理论中推导出了原初张量扰动谱的通式。还讨论了物质密度扰动的演化。
Recently, it was argued that gravity with the square of the Ricci tensor can be stabilized by adding constraints to the theory in a Lorentz violating way. This was so far demonstrated for fluctuations on the Minkowski/de Sitter background. We show that the same scheme works equally well for removing Ostrogradski’s ghost from fluctuations on a cosmological background in generic-type theories of gravity. As an application, we derive the general formula for the spectrum of primordial tensor perturbations from the stabilized theory. The evolution of matter density perturbations is also discussed.