论文标题
黑暗能源调查3年结果：宇宙剪切分析在谐波空间中的宇宙剪切构成
Dark Energy Survey Year 3 results: cosmological constraints from the analysis of cosmic shear in harmonic space
论文作者
论文摘要
我们根据黑暗能源调查的前三年（des Y3）观察到的数据，根据宇宙剪切图的角度功率谱分析宇宙学的约束。我们的测量基于伪c_ \ ell $方法，并提供了与实际空间中两点相关函数互补的视图，因为已知两个估计量由于缩放缩小而以不同的方式压缩和选择高斯信息。它们也可能会受到系统效应和理论不确定性的影响，例如重子和内在对准（IA），这使得该分析是一个重要的交叉检查。在$λ$ CDM的上下文中，并使用与DES Y3真实空间分析相同的基准模型，我们发现$ {s_8 \equivσ_8\ sqrt {ω_ {ω_ {\ rm m} /0.3} = 0.793^= 0.793^{+0.038} {+0.038} _ {+0.038} _ { - 0.025} $ { - 0.025} 0.784 \ pm 0.026} $包括剪切比。该约束在实际空间分析中的预期统计波动范围内，并且与非高斯统计数据的DES〜Y3分析一致，但偏向于$ s_8 $的略高价值，这使Planck Cosmic Microwave背景2018的紧张局势从这项工作中的实际空间分析中的2.3σ$降低到了$1.5σ$。我们探索的IA模型少于我们的基准分析中采用的模型，对更复杂的模型没有明确的偏好。我们还包括小尺度，使用增加的傅立叶模式切割到$ k _ {\ rm max} = {5} {h {\ rm mpc}^{ - 1}} $，它允许在离开宇宙学约束的同时限制baryonic反馈。最后，我们目前对线性物质功率谱进行了大致重建，发现该频谱比Planck 2018的预测低约20 \％，这反映了$1.5σ$ s_8 $ value。
We present cosmological constraints from the analysis of angular power spectra of cosmic shear maps based on data from the first three years of observations by the Dark Energy Survey (DES Y3). Our measurements are based on the pseudo-$C_\ell$ method and offer a view complementary to that of the two-point correlation functions in real space, as the two estimators are known to compress and select Gaussian information in different ways, due to scale cuts. They may also be differently affected by systematic effects and theoretical uncertainties, such as baryons and intrinsic alignments (IA), making this analysis an important cross-check. In the context of $Λ$CDM, and using the same fiducial model as in the DES Y3 real space analysis, we find ${S_8 \equiv σ_8 \sqrt{Ω_{\rm m}/0.3} = 0.793^{+0.038}_{-0.025}}$, which further improves to ${S_8 = 0.784\pm 0.026 }$ when including shear ratios. This constraint is within expected statistical fluctuations from the real space analysis, and in agreement with DES~Y3 analyses of non-Gaussian statistics, but favors a slightly higher value of $S_8$, which reduces the tension with the Planck cosmic microwave background 2018 results from $2.3σ$ in the real space analysis to $1.5σ$ in this work. We explore less conservative IA models than the one adopted in our fiducial analysis, finding no clear preference for a more complex model. We also include small scales, using an increased Fourier mode cut-off up to $k_{\rm max}={5}{h{\rm Mpc}^{-1}}$, which allows to constrain baryonic feedback while leaving cosmological constraints essentially unchanged. Finally, we present an approximate reconstruction of the linear matter power spectrum at present time, which is found to be about 20\% lower than predicted by Planck 2018, as reflected by the $1.5σ$ lower $S_8$ value.
