论文标题
空测量一致性，重力镜头和CMB强度曲线
Null geodesic congruences, gravitational lensing and CMB intensity profile
论文作者
论文摘要
众所周知，宇宙微波背景（CMB）温度波动是通过重力镜头修饰的，因为光子的角度位置通过度量扰动改变。我们在用标量和张量模式的时空时期对弗里德曼·罗伯逊 - 沃克（FRW）时空进行了大地偏差的背景下重新考虑这种效果。我们首先通过使用无效的测量方程的溶液来提供Sachs-Wolfe效应的替代推导。然后，我们确定二维诱导的度量标准，在解耦后对应于光束光束的空测量一致性的横截面上。该度量标准的变异可以分解为膨胀和剪切，显示出产生的非平凡强度曲线，可以以类似于偏振张量的Stokes参数类似的三个变量来表征。
It is known that the Cosmic Microwave Background (CMB) temperature fluctuations are modified by gravitational lensing since the angular positions of photons are altered by the metric perturbations. We reconsider this effect in the context of geodesic deviation on a perturbed Friedmann-Robertson-Walker (FRW) spacetime with scalar and tensor modes. We first give an alternative derivation of the Sachs-Wolfe effect by using the solutions of the null geodesic equation. Then, we determine the two-dimensional induced metric on the transverse cross section of the null geodesic congruence corresponding to a beam of photons after decoupling. This metric, whose variation along the congruence can be decomposed as expansion and shear, is shown to produce a nontrivial intensity profile which can be characterized by three variables analogous to the Stokes parameters of the polarization tensor.
