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arXiv 2102.08315astro-ph.CO
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检验单圈星系偏差:来自功率谱的宇宙学约束

Testing one-loop galaxy bias: cosmological constraints from the power spectrum

Andrea Pezzotta, Martin Crocce, Alexander Eggemeier, Ariel G. Sánchez, Román Scoccimarro

摘要:

我们调查的影响,不同的假设在建模的单圈星系偏差的宇宙学参数的恢复,作为后续的分析中所做的第一篇论文的系列在固定的宇宙学。我们使用三个不同的合成星系样本的聚类特性相匹配的CMASS和LOWZ目录的BOSS和SDSS的主要星系样本。我们调查的相关性,允许无论是短期的非局域性或尺度依赖的随机性,通过拟合实空间星系的自功率谱或组合的星系星系和星系物质的功率谱。从拟合优度($χ^2$),宇宙学参数(FoB)的无偏性,和品质因数(FoM)之间的比较,我们发现,一个四参数模型(线性,二次,立方非局部偏差,和恒定的散粒噪声)与固定的二次潮汐偏差提供了一个强大的建模选择的自动功率谱的三个样本,高达$k_{\rm max}=0.3\,h\,\mathrm{Mpc}^{-1}$和$6\,h^{-3}\,\mathrm{Gpc}^3$的有效体积。相反,联合分析的两个观测失败在较大的尺度,和模型扩展与更高的衍生物或尺度相关的散粒噪声是必要的,以达到类似的$k_{\rm max}$,后者提供了最稳定的结果。这些发现是用三种混合或微扰的物质功率谱处方\texttt{RESPRESSO}、gRPT和EFT获得的。在所有情况下,包含尺度相关散粒噪声增加了模型在FoB和$χ^2$方面的有效性范围。有趣的是,这些模型的扩展与额外的自由参数不一定会导致宇宙学参数$\left(h,\,Ω_ch^2,\,A_s\right)$的最大可实现的FoM的增加,这通常是一致的更简单的模型在较小的$k_{\rm max}$。

英文摘要:

We investigate the impact of different assumptions in the modeling of one-loop galaxy bias on the recovery of cosmological parameters, as a follow up of the analysis done in the first paper of the series at fixed cosmology. We use three different synthetic galaxy samples whose clustering properties match the ones of the CMASS and LOWZ catalogues of BOSS and the SDSS Main Galaxy Sample. We investigate the relevance of allowing for either short range non-locality or scale-dependent stochasticity by fitting the real-space galaxy auto power spectrum or the combination of galaxy-galaxy and galaxy-matter power spectrum. From a comparison among the goodness-of-fit ($χ^2$), unbiasedness of cosmological parameters (FoB), and figure-of-merit (FoM), we find that a four-parameter model (linear, quadratic, cubic non-local bias, and constant shot-noise) with fixed quadratic tidal bias provides a robust modelling choice for the auto power spectrum of the three samples, up to $k_{\rm max}=0.3\,h\,\mathrm{Mpc}^{-1}$ and for an effective volume of $6\,h^{-3}\,\mathrm{Gpc}^3$. Instead, a joint analysis of the two observables fails at larger scales, and a model extension with either higher derivatives or scale-dependent shot-noise is necessary to reach a similar $k_{\rm max}$, with the latter providing the most stable results. These findings are obtained with three, either hybrid or perturbative, prescriptions for the matter power spectrum, \texttt{RESPRESSO}, gRPT and EFT. In all cases, the inclusion of scale-dependent shot-noise increases the range of validity of the model in terms of FoB and $χ^2$. Interestingly, these model extensions with additional free parameters do not necessarily lead to an increase in the maximally achievable FoM for the cosmological parameters $\left(h,\,Ω_ch^2,\,A_s\right)$, which are generally consistent to those of the simpler model at smaller $k_{\rm max}$.

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