We study the gravitational waves (GWs) in modified Gauss–Bonnet gravity. Applying the metric perturbation around a cosmological background, we obtain explicit expressions for the wave equations. It is shown that the speed of the traceless mode is equal to the speed of light. An additional massive scalar mode appears in the propagation of the GWs. To find phenomena beyond the general relativity, the scalar mode mass is calculated as a function of the background curvature in some typical models.

中文翻译：

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修正高斯-博内引力中的引力波

我们研究了修改后的 Gauss-Bonnet 引力中的引力波 (GW)。在宇宙学背景周围应用度量扰动，我们获得了波动方程的显式表达式。结果表明，无迹模式的速度等于光速。在 GW 的传播中出现了一个额外的大规模标量模式。为了发现广义相对论之外的现象，在一些典型模型中，标量模式质量被计算为背景曲率的函数。