论文标题
$ S_8 $张力的非线性解决方案？
A non-linear solution to the $S_8$ tension?
论文作者
论文摘要
弱星系镜头调查始终报道了该物质波动频谱的幅度较低，该幅度比$ S_8 $参数衡量，比$λ{\ rm cdm} $ cesmology在$ planck $中的$λ{\ rm cdm} $宇宙学中的预期。但是，扩展历史记录遵循$ planck $ $ $ $ $ $ cdm} $宇宙学的预测，以及对宇宙微波背景各向异性镜头的测量值也很高。红移空间失真测量值似乎也与$ planck $ $ $λ{\ rm cdm} $一致。在本文中，我们认为这些观察结果可以与$ planck $ $ $ $ cdm} $ cesmology对待，如果在非线性尺度上比弱星系镜片分析中所假设的功率谱在非线性尺度上更强烈地抑制了这些观察结果。我们通过拟合一个参数模型来证明这一点，该模型表征了对非线性功率谱的抑制作用，将其与儿童1000弱透镜测量值一起。这种抑制可以归因于影响非线性尺度的暗物质的新特性，或者是由于物质对重的反馈过程的响应的响应，这些反馈过程比最近的宇宙学模拟中预期的要强。我们提出的解释可以通过测量线性尺度上物质波动频谱的幅度进行测试，特别是通过即将进行的Galaxy和Quasar Redshift Surveys的高精度红移空间失真测量。
Weak galaxy lensing surveys have consistently reported a lower amplitude for the matter fluctuation spectrum, as measured by the $S_8$ parameter, than expected in the $Λ{\rm CDM}$ cosmology favoured by $Planck$. However, the expansion history follows the predictions of the $Planck$ $Λ{\rm CDM}$ cosmology to high accuracy, as do measurements of lensing of the cosmic microwave background anisotropies. Redshift space distortion measurements also appear to be consistent with $Planck$ $Λ{\rm CDM}$. In this paper, we argue that these observations can be reconciled with the $Planck$ $Λ{\rm CDM}$ cosmology if the matter power spectrum is suppressed more strongly on non-linear scales than assumed in analyses of weak galaxy lensing. We demonstrate this point by fitting a one-parameter model, characterising a suppression of the non-linear power spectrum, to the KiDS-1000 weak lensing measurements. Such a suppression could be attributed to new properties of the dark matter that affect non-linear scales, or to a response of the matter fluctuations to baryonic feedback processes that are stronger than expected from recent cosmological simulations. Our proposed explanation can be tested using measurements of the amplitude of the matter fluctuation spectrum on linear scales, in particular via high precision redshift space distortion measurements from forthcoming galaxy and quasar redshift surveys.
