Evolution of gravitational waves in the high-energy regime of brane-world cosmology
Evolution of gravitational waves in the high-energy regime of brane-world cosmology
复制标题
DOI：
10.1016/j.physletb.2005.01.024
复制
发表时间：
2004-10
影响因子：
4.4
通讯作者：
T. Hiramatsu;K. Koyama;A. Taruya
中科院分区：
文献类型：
--
作者：
T. Hiramatsu;K. Koyama;A. Taruya
我们讨论了嵌入在五维反德西特（AdS 5）体时空中的膜世界宇宙学中暴胀后引力波（GW）的演化。在膜世界的情况下，GWs的演化受到非标准宇宙膨胀和Kaluza-Klein（KK）模激发的影响，这在宇宙的高能区是重要的。在Poincaré坐标系下数值求解了引力波的波动方程。使用一个合理的初始条件，从通货膨胀，我们发现，虽然在大规模的行为是敏感的过渡时间从通货膨胀到辐射占主导地位的时代，膜上的GWs的振幅是不敏感的，如果过渡发生在足够早的视界再入之前的时间。结果表明，KK模的激发抑制了引力波的振幅，这种效应可以补偿非标准宇宙学膨胀对引力波的增强。在此基础上，讨论了高能效应对GW本底的影响。
We discuss the evolution of gravitational waves (GWs) after inflation in a brane-world cosmology embedded in five-dimensional anti-de Sitter (AdS5) bulk spacetime. In a brane-world scenario, the evolution of GWs is affected by the non-standard cosmological expansion and the excitation of the Kaluza–Klein (KK) modes, which are significant in the high-energy regime of the universe. We numerically solve the wave equation of GWs in the Poincaré coordinates of the AdS5spacetime. Using a plausible initial condition from inflation, we find that, while the behavior of GWs in the bulk is sensitive to the transition time from inflation to the radiation-dominated epoch, the amplitude of GWs on the brane is insensitive to this time if the transition occurs early enough before horizon reentry. As a result, the amplitude of GWs is suppressed by the excitation of KK-modes and the effect may compensate the enhancement of the GWs by the non-standard cosmological expansion. Based on this, the influence of the high-energy effects on the GW backgrounds is discussed.