论文标题
$γ$射线准时运行
$γ$ rays run on time
论文作者
论文摘要
辐射的显着吸收通常伴随着折射。 $γ$射线旅行宇宙距离并非如此。我们表明，折射指数的真实和虚构部分确实是可以相称的，因为它们与分散关系相关，但是当转向物理可观察物时，（有限的）光学深度大于相对于引力辐射的伽马射线的（无限）时间延迟的（无限）时间延迟。在数值上解决明显矛盾的因素是$e_γ/h_0 $，分别来自基本波属性（Bouguer-Beer-Lambert Law）和标准宇宙学模型。
Significant absorption of radiation is usually accompanied by refraction. This is not the case for $γ$ rays travelling cosmic distances. We show that the real and imaginary parts of the refraction index are indeed commensurable, as they are related by dispersion relations, but when turning to physical observables, the (finite) optical depth is way larger than the (infinitesimal) time delay of the gamma rays relative to gravitational radiation. The numerically large factor solving the apparent contradiction is $E_γ/H_0$ arising from basic wave properties (Bouguer-Beer-Lambert law) and the standard cosmological model, respectively.
