论文标题
重力中的重力波，重力有两个小四源校正
Gravitational wave from cosmic inflation in a gravity with two small four-derivative corrections
论文作者
论文摘要
我们研究了一种通货膨胀宇宙学模型，其中最小耦合的标量场理论通过其他校正项修改。在有效的现场理论的背景下，温伯格所说的最一般的十个更正术语中，我们仅考虑两个术语，$ f_1（ϕ）r^2 $和$ f_2（ϕ）r^{ab} r_ {ab {ab {ab {ab} $，遵循Noh和Hwang的工作，在$ f_1 $ and $ f_1 $ and $ f_2 $是常数的。背景宇宙的第四阶微分方程和张量式扰动是从该模型中得出的。我们表明，这些方程式可以简化为二阶方程，假设$ f_n $很小。从这些近似方程式中，我们发现重力波的传播速度略低于由于$ f_2 $项而引起的光速，并且张量型扰动的演变在较大规模的限制中保守。
We investigate a model of inflationary cosmology where the minimally coupled scalar field theory is modified by additional correction terms. Among the most general ten correction terms remarked by Weinberg in context of effective field theory, we consider only two terms, $f_1(ϕ) R^2$ and $f_2(ϕ) R^{ab}R_{ab}$, following the work by Noh and Hwang where $f_1$ and $f_2$ are constant. The fourth order differential equations for the background universe and the tensor-type perturbation are derived out of this model. We show that these equations can be reduced to second order equations, supposing that $f_n$ are small. From these approximated equations, we find that the propagation speed of gravitational wave is slightly less than the speed of light due to $f_2$ term, and that the evolution of the tensor-type perturbation is conserved in the large scale limit.
