论文标题
从弱镜头上的量规宇宙学雅各比不变的雅各比图
The gauge invariant cosmological Jacobi map from weak lensing at leading order
论文作者
论文摘要
我们在扰动理论中以一阶的一阶计算弱的镜头jacobi图，并表明它既是规范不变又对称。因此，线性扰动不会引起任何旋转。但是，矢量和张量的扰动确实会诱导剪切中的$ b $ modes。我们表明，与文献中经常声称的相反，剪切$ b $ mmode功率谱并未由旋转功率谱完全确定。另外，$ e $ mmode剪切功率谱并不由收敛功率谱确定。尽管这种差异对于标量扰动很小，但它与张量扰动非常相关，即引力波。
We compute the weak lensing Jacobi map at first order in perturbation theory and show that it is both, gauge invariant and symmetric. Linear perturbations therefore do not induce any rotation. However, vector and tensor perturbations do induce $B$-modes in the shear. We show that contrary to what is often claimed in the literature, the shear $B$-mode power spectrum is not fully determined by the rotation power spectrum. Also the $E$-mode shear power spectrum is not determined by the convergence power spectrum. While this difference is small for scalar perturbations, it becomes very relevant for tensor perturbations, i.e. gravitational waves.
