论文标题
使用二分和三点统计的弱透镜系统效应的自我校准
Self-calibration of weak lensing systematic effects using combined two- and three-point statistics
论文作者
论文摘要
我们研究了在类似欧几里得的调查中使用弱透镜双光谱与功率谱一起控制系统不确定性的前景。考虑了三种系统的效果：星系的内在比对，层析成像分布的不确定性以及剪切信号测量中的乘法偏差。我们发现双光谱在缓解这些系统错误方面非常有效。共同的功率谱和双光谱分析同时改变了所有三种系统学，降低了宇宙学参数可信区域的面积$ω__\ mathrm {m} $和$σ_8$和$σ_8$的一个因子为90倍，并且单独使用20次限制的黑暗能量方程的两个参数，并且几乎是20元的强大方法，并且几乎是20元的基础。先验与欧几里得指定的准确性要求一致。我们还证明，包括双光谱自我校准，将所有三个系统效应都带入即将产生的弱透镜调查所需的严格水平，从而减少了对外部校准数据的需求。
We investigate the prospects for using the weak lensing bispectrum alongside the power spectrum to control systematic uncertainties in a Euclid-like survey. Three systematic effects are considered: the intrinsic alignment of galaxies, uncertainties in the means of tomographic redshift distributions, and multiplicative bias in the measurement of the shear signal. We find that the bispectrum is very effective in mitigating these systematic errors. Varying all three systematics simultaneously, a joint power spectrum and bispectrum analysis reduces the area of credible regions for the cosmological parameters $Ω_\mathrm{m}$ and $σ_8$ by a factor of 90 and for the two parameters of a time-varying dark energy equation of state by a factor of almost 20, compared with the baseline approach of using the power spectrum alone and of imposing priors consistent with the accuracy requirements specified for Euclid. We also demonstrate that including the bispectrum self-calibrates all three systematic effects to the stringent levels required by the forthcoming generation of weak lensing surveys, thereby reducing the need for external calibration data.
