论文标题
建立具有健康可行的标量和张量扰动的立方重力
Building cubic gravity with healthy and viable scalar and tensor perturbations
论文作者
论文摘要
我们研究了足够的条件，在扰动水平上，立方重力在健康状态下是健康且可行的条件。我们对标量和张量扰动进行详细分析。我们强加了这样的要求，即两个标量电势，其比率是牛顿后参数$γ$，应仅偏离最小形成一般相对论。此外，关于张量的扰动，我们对Ligo-Virgo和Fermi Gamma-ray爆发观测值施加满足，因此，我们导致具有重力波速度等于光速的引力波方程，而在分散关系中，唯一的偏离率出现了与一般相对性的偏差。此外，我们表明，立方重力表现出有效的牛顿常数，取决于模型参数，背景进化以及波数尺度。因此，通过要求其偏离标准牛顿常数在观察范围内，我们提取了对单个耦合参数$β$的约束。
We investigate sufficient conditions under which cubic gravity is healthy and viable at the perturbation level. We perform a detailed analysis of the scalar and tensor perturbations. We impose the requirement that the two scalar potentials, whose ratio is the post-Newtonian parameter $γ$, should deviate only minimally form general relativity. Additionally, concerning tensor perturbations we impose satisfaction of the LIGO-VIRGO and Fermi Gamma-ray Burst observations, and thus we result to a gravitational-wave equation with gravitational-wave speed equal to the speed of light, and where the only deviation from general relativity appears in the dispersion relation. Furthermore, we show that cubic gravity exhibits an effective Newton's constant that depends on the model parameter, on the background evolution, and on the wavenumber scale. Hence, by requiring its deviation from the standard Newton's constant to be within observational bounds we extract the constraints on the single coupling parameter $β$.
