论文标题
弱透镜角功率光谱中的一般相对论效应
General Relativistic Effects in Weak Lensing Angular Power Spectra
论文作者
论文摘要
即将进行的弱透镜调查的进步提出了新的挑战，可以准确对镜头观测值进行建模。欧几里得的宽天空覆盖范围使角度尺度降低到$ l_ \ mathrm {min} = 10 $可访问。在如此大的角度尺度上，一般相对论效应表现出来，并且仅由标准透镜收敛正确地描述了镜头放大。在文献中，视线速度对放大倍数的影响（称为多普勒放大倍率）的影响已经在文献中得到广泛认可。特别是，建议可以通过测量宇宙剪切和放大倍率来提取多普勒放大倍率。在这项工作中，我们指出了有关此方法的两个先前被忽视的方面。首先，通过与标准透镜收敛性的非变化跨项来降低多普勒放大倍率的影响。当源在宽度$ΔZ\约0.1 $的箱中平均，例如在Euclid的层析成像弱透镜调查中，这一点尤其重要。其次，一般相对论的潜在项略微增强了信号。我们介绍了大尺度上弱透镜角功率谱中所有相对论效应的数值计算。
Advances in upcoming weak lensing surveys pose new challenges for an accurate modeling of the lensing observables. The wide sky coverage of Euclid makes angular scales down to $l_\mathrm{min}=10$ accessible. At such large angular scales, general relativistic effects manifest themselves, and the lensing magnification cannot be correctly described by the standard lensing convergence only. The impact of line-of-sight velocities on the magnification angular power spectrum, referred to as the Doppler magnification, is already well recognized in literature. In particular, it was suggested that the Doppler magnification could be extracted by measurements of both cosmic shear and magnification. In this work, we point out two previously neglected aspects with respect to this method. Firstly, the impact of the Doppler magnification is reduced through non-vanishing cross terms with the standard lensing convergence. This is particularly relevant when the sources are averaged over a bin of width $Δz\approx 0.1$, such as in Euclid's tomographic weak lensing survey. Secondly, general relativistic potential terms slightly enhance the signal. We present numerical calculations of all relativistic effects in the weak lensing angular power spectra on large scales.
