Emulating power spectra for pre- and post-reconstructed galaxy samples
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| Main Authors: | , , , , , , , , , , , , |
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| Format: | Preprint |
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2023
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| _version_ | 1866911783430651904 |
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| author | Wang, Yuting Zhao, Ruiyang Zhai, Zhongxu Koyama, Kazuya Percival, Will J. Guo, Hong Li, Yin Zhao, Gong-Bo Nishimichi, Takahiro Gil-Marín, Héctor Feng, Yonghao Zhang, Hanyu Wu, Yi |
| author_facet | Wang, Yuting Zhao, Ruiyang Zhai, Zhongxu Koyama, Kazuya Percival, Will J. Guo, Hong Li, Yin Zhao, Gong-Bo Nishimichi, Takahiro Gil-Marín, Héctor Feng, Yonghao Zhang, Hanyu Wu, Yi |
| contents | The small-scale linear information in galaxy samples typically lost during non-linear growth can be restored to a certain level by the density field reconstruction, which has been demonstrated for improving the precision of the baryon acoustic oscillations (BAO) measurements. As proposed in the literature, a joint analysis of the power spectrum before and after the reconstruction enables an efficient extraction of information carried by high-order statistics. However, the statistics of the post-reconstruction density field are difficult to model. In this work, we circumvent this issue by developing an accurate emulator for the pre-reconstructed, post-reconstructed, and cross power spectra ($P_{\rm pre}$, $P_{\rm post}$, $P_{\rm cross}$) up to $k=0.5~h~{\rm Mpc^{-1}}$ based on the \textsc{Dark Quest} N-body simulations. The accuracy of the emulator is at percent level, namely, the error of the emulated monopole and quadrupole of the power spectra is less than $1\%$ and $10\%$ of the ground truth, respectively. A fit to an example power spectra using the emulator shows that the constraints on cosmological parameters get largely improved using $P_{\rm pre}$+$P_{\rm post}$+$P_{\rm cross}$ with $k_{\rm max}=0.25~h~{\rm Mpc^{-1}}$, compared to that derived from $P_{\rm pre}$ alone, namely, the constraints on ($Ω_m$, $H_0$, $σ_8$) are tightened by $\sim41 \%-55\%$, and the uncertainties of the derived BAO and RSD parameters ($α_{\perp}$, $α_{||}$, $fσ_8$) shrink by $\sim 28\%-54\%$, respectively. This highlights the complementarity among $P_{\rm pre}$, $P_{\rm post}$ and $P_{\rm cross}$, which demonstrates the efficiency and practicability of a joint $P_{\rm pre}$, $P_{\rm post}$ and $P_{\rm cross}$ analysis for cosmological implications. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2311_05848 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Emulating power spectra for pre- and post-reconstructed galaxy samples Wang, Yuting Zhao, Ruiyang Zhai, Zhongxu Koyama, Kazuya Percival, Will J. Guo, Hong Li, Yin Zhao, Gong-Bo Nishimichi, Takahiro Gil-Marín, Héctor Feng, Yonghao Zhang, Hanyu Wu, Yi Cosmology and Nongalactic Astrophysics The small-scale linear information in galaxy samples typically lost during non-linear growth can be restored to a certain level by the density field reconstruction, which has been demonstrated for improving the precision of the baryon acoustic oscillations (BAO) measurements. As proposed in the literature, a joint analysis of the power spectrum before and after the reconstruction enables an efficient extraction of information carried by high-order statistics. However, the statistics of the post-reconstruction density field are difficult to model. In this work, we circumvent this issue by developing an accurate emulator for the pre-reconstructed, post-reconstructed, and cross power spectra ($P_{\rm pre}$, $P_{\rm post}$, $P_{\rm cross}$) up to $k=0.5~h~{\rm Mpc^{-1}}$ based on the \textsc{Dark Quest} N-body simulations. The accuracy of the emulator is at percent level, namely, the error of the emulated monopole and quadrupole of the power spectra is less than $1\%$ and $10\%$ of the ground truth, respectively. A fit to an example power spectra using the emulator shows that the constraints on cosmological parameters get largely improved using $P_{\rm pre}$+$P_{\rm post}$+$P_{\rm cross}$ with $k_{\rm max}=0.25~h~{\rm Mpc^{-1}}$, compared to that derived from $P_{\rm pre}$ alone, namely, the constraints on ($Ω_m$, $H_0$, $σ_8$) are tightened by $\sim41 \%-55\%$, and the uncertainties of the derived BAO and RSD parameters ($α_{\perp}$, $α_{||}$, $fσ_8$) shrink by $\sim 28\%-54\%$, respectively. This highlights the complementarity among $P_{\rm pre}$, $P_{\rm post}$ and $P_{\rm cross}$, which demonstrates the efficiency and practicability of a joint $P_{\rm pre}$, $P_{\rm post}$ and $P_{\rm cross}$ analysis for cosmological implications. |
| title | Emulating power spectra for pre- and post-reconstructed galaxy samples |
| topic | Cosmology and Nongalactic Astrophysics |
| url | https://arxiv.org/abs/2311.05848 |