论文标题
辐射主导的宇宙中的重力张量和声波：Weyl曲率和极化模式
Gravitational Tensor and Acoustic Waves in A Radiation Dominated Universe: Weyl Curvature and Polarization Patterns
论文作者
论文摘要
我们提供的证据表明，具有4D辐射主导的宇宙的重力辐射，带有状态方程$ W = 1/3 $，由两个组成部分组成：Helicity-2 Gractons和无质量的标量声波。就物理上而言，我们希望Weyl张量成分的均匀溶液在观察者位于宇宙学重力辐射的孤立天体物理学来源的远处时，与其不均匀的对应物的近似值是一个很好的近似值。我们明确地表明，这些均匀和不均匀的解决方案都从规范不变的张量{\ it和}的两个Bardeen（声学）标量中获得了贡献。因此，这些WEYL张量计算的比较使我们不仅可以在高频限制下识别相应的重力张量和标量辐射；而且它们的振荡极化模式。
We provide evidence that gravitational radiation in a 4D radiation-dominated universe, with equation-of-state $w=1/3$, consists of two components: helicity-2 gravitons and massless scalar acoustic waves. On physical grounds, we would expect the homogeneous solution of the Weyl tensor components to be a good approximation to its inhomogeneous counterparts, whenever the observer is located well in the far zone of an isolated astrophysical source of cosmological gravitational radiation. We show explicitly that these homogeneous and inhomogeneous solutions both receive contributions from the gauge-invariant tensor {\it and} the two Bardeen (acoustic) scalars. Comparison of these Weyl tensor computations thus allows us to not only identify, in the high frequency limit, the corresponding gravitational tensor and scalar radiation; but also their oscillatory polarization patterns.
