Stable cosmological solutions in degenerate theory of gravity
Stable cosmological solutions in degenerate theory of gravity
复制标题
DOI：
10.1016/j.physletb.2018.07.009
复制
发表时间：
2018-03
影响因子：
4.4
通讯作者：
R. Kase;Rampei Kimura;A. Naruko;Daisuke Yoshida
中科院分区：
文献类型：
--
作者：
R. Kase;Rampei Kimura;A. Naruko;Daisuke Yoshida
我们研究扩展的矢量张量理论的宇宙学应用，其拉格朗日包含两个关于度规和矢量场的导数。在均匀各向同性宇宙的假设下，我们导出了背景方程，并研究了背景上宇宙学扰动的性质。我们发现了一个健康的宇宙学解的例子，在非平凡的退化引力理论的第一次，这些扰动不遭受任何不稳定性，即鬼和梯度不稳定性。
We study cosmological applications of extended vector–tensor theories, whose Lagrangians contain up to two derivatives with respect to metric and vector field. We derive background equations under the assumption of homogeneous and isotropic universe and study the nature of cosmological perturbations on top of the background. We found an example of healthy cosmological solutions in non-trivial degenerate theory of gravity for the first time, where those perturbations do not suffer from any instabilities, that is, ghost and gradient instabilities.