Cosmological constraints from the full-shape galaxy power spectrum in SDSS-III BOSS using the BACCO hybrid Lagrangian bias emulator
arxiv(2024)
摘要
We present a novel analysis of the redshift-space power spectrum of galaxies
in the SDSS-III BOSS survey. Our methodology improves upon previous analyses by
using a theoretical model based on cosmological simulations coupled with a
perturbative description of the galaxy-matter connection and a phenomenological
prescription of Fingers of God. This enables a very robust analysis down to
mildly non-linear scales, k∼ 0.4 h Mpc^-1. We carried out a
number of tests on mock data, different subsets of BOSS, and using model
variations, all of which support the robustness of our analysis. Our results
provide constraints on σ_8, Ω_m, h, and S_8 ≡σ_8
√(Ω_ m/0.3). Specifically, we measure Ω_m=0.301± 0.011,
σ_8=0.745^+0.028_-0.035, h=0.705± 0.015, and S_8 =
0.747^+0.032_-0.039 when all the nuisance parameters of our model are left
free. By adopting relationships among bias parameters measured in galaxy
formation simulations, the value of S_8 remains consistent whereas
uncertainties are reduced by ∼20%. Our cosmological constraints are some
of the strongest obtained with the BOSS power spectrum alone: they exhibit a
2.5-3.5σ tension with the results of the Planck satellite,
agreeing with the lower values of S_8 derived from gravitational lensing.
However, the cosmological model preferred by Planck is still a good fit
to the BOSS data, assuming small departures from physical bias priors and,
therefore, cannot be excluded at high significance. We conclude that, at the
present, the BOSS data alone does not show strong evidence for a tension
between the predictions of ΛCDM for the high- and low-redshift
Universe.
更多查看译文
AI 理解论文
溯源树
样例
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要