In this work,we investigate a joint fitting approach based on theoretical models of power spectra associated with density-field reconstruction.Specifically,we consider the matter auto-power spectra before and after ba...In this work,we investigate a joint fitting approach based on theoretical models of power spectra associated with density-field reconstruction.Specifically,we consider the matter auto-power spectra before and after baryon acoustic oscillations(BAO)reconstruction,as well as the cross-power spectrum between the pre-and post-reconstructed density fields.We present redshift-space models for these three power spectra at the one-loop level within the framework of standard perturbation theory,and perform a joint analysis using three types of power spectra,and quantify their impact on parameter constraints.When restricting the analysis to wavenumbers k≤0.2 h Mpc^(−1)and adopting a smoothing scale of R_(s)=15 h^(−1)Mpc,we find that incorporating all three power spectra improves parameter constraints by approximately 11%–16%compared to using only the post-reconstruction power spectrum,with the Figure of Merit increasing by 10.5%.These results highlight the advantages of leveraging multiple power spectra in BAO reconstruction,ultimately enabling more precise cosmological parameter estimation.展开更多
We propose a new consistency test for theΛCDM cosmology using baryonic acoustic oscillations(BAO)and redshift space distortion(RSD)measurements from galaxy redshift surveys.Specifically,we determine the peak position...We propose a new consistency test for theΛCDM cosmology using baryonic acoustic oscillations(BAO)and redshift space distortion(RSD)measurements from galaxy redshift surveys.Specifically,we determine the peak position of fσ8(z)in redshift z offered by an RSD measurement,and compare it to the one predicted by the BAO observables assuming a flatΛCDM cosmology.We demonstrate this new test using the simulated data for the DESI galaxy survey,and argue that this test complements those using the background observables alone,and is less subject to systematics in the RSD analysis,compared to traditional methods using values of fσ8(z)directly.展开更多
The baryon acoustic oscillations (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian.The ...The baryon acoustic oscillations (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian.The combination of the power spectra before and after the BAO reconstruction helps break degeneracies among parameters,then improves the constraints on cosmological parameters.It is therefore important to estimate the covariance matrix between pre-and post-reconstructed power spectra.In this work,we use perturbation theory to estimate the covariance matrix of the related power spectra multipoles,and check the accuracy of the derived covariance model using a large suite of dark matter halo catalogs at z=0.5.We find that the diagonal part of the auto covariance is well described by the Gaussian prediction,while the cross covariance deviates from the Gaussian prediction quickly when k>0.1 h Mpc^(-1).Additionally,we find the non-Gaussian effect in the nondiagonal part of the cross covariance is comparable to,or even stronger than,the pre-reconstruction covariance.By adding the non-Gaussian contribution,we obtain good agreement between analytical and numerical covariance matrices in the non-diagonal part up to k■0.15 h Mpc^(-1).The agreement in the diagonal part is also improved,bu still under-predicts the correlation in the cross covariance block.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.12525301)supported by the Science and Technology Facilities Council(STFC)under Grant ST/W001225/1+6 种基金supported by JSPS KAKENHI grant Nos.JP22H00130 and JP20H05855further acknowledges support form the National Key R&D Program of China No.(2022YFF0503404,2023YFA1607800,2023YFA1607803)the National Natural Science Foundation of China(NSFC,Grant Nos.12273048 and 12422301)the CAS Project for Young Scientists in Basic Research(No.YSBR-092)support from the CAS Project for Young Scientists in Basic Research(No.YSBR092)the China Manned Space Projectthe New Cornerstone Science Foundation through the XPLORER Prize.
文摘In this work,we investigate a joint fitting approach based on theoretical models of power spectra associated with density-field reconstruction.Specifically,we consider the matter auto-power spectra before and after baryon acoustic oscillations(BAO)reconstruction,as well as the cross-power spectrum between the pre-and post-reconstructed density fields.We present redshift-space models for these three power spectra at the one-loop level within the framework of standard perturbation theory,and perform a joint analysis using three types of power spectra,and quantify their impact on parameter constraints.When restricting the analysis to wavenumbers k≤0.2 h Mpc^(−1)and adopting a smoothing scale of R_(s)=15 h^(−1)Mpc,we find that incorporating all three power spectra improves parameter constraints by approximately 11%–16%compared to using only the post-reconstruction power spectrum,with the Figure of Merit increasing by 10.5%.These results highlight the advantages of leveraging multiple power spectra in BAO reconstruction,ultimately enabling more precise cosmological parameter estimation.
基金supported by the Chinese Scholarship CouncilSTFC+6 种基金supported by NSFC grants 11925303,11720101004 and 11890691supported by NSFC Grant 11890691by the Youth Innovation Promotion Association CASby the Nebula Talents Program of NAOCsupported by the National Key Basic Research and Development Program of Chinaa grant of CAS Interdisciplinary Innovation Teamthe science research grants from the China Manned Space Project with No.CMS-CSST-2021-B01。
文摘We propose a new consistency test for theΛCDM cosmology using baryonic acoustic oscillations(BAO)and redshift space distortion(RSD)measurements from galaxy redshift surveys.Specifically,we determine the peak position of fσ8(z)in redshift z offered by an RSD measurement,and compare it to the one predicted by the BAO observables assuming a flatΛCDM cosmology.We demonstrate this new test using the simulated data for the DESI galaxy survey,and argue that this test complements those using the background observables alone,and is less subject to systematics in the RSD analysis,compared to traditional methods using values of fσ8(z)directly.
基金supported by National Key R&D Program of China No.2023YFA1607803National Natural Science Foundation of China (NSFC,grant No.11925303)+9 种基金by the CAS Project for Young Scientists in Basic Research (No.YSBR-092)supported by the Chinese Scholarship Council (CSC) and the University of Portsmouthsupported by the STFC grant ST/W001225/1.Y.W.supported by National Natural Science Foundation of China (NSFC,grant Nos.12273048 and 12422301)by National Key R&D Program of China No.2022YFF0503404by the Youth Innovation Promotion Association CASby the Nebula Talents Program of NAOC.G.B.Z.supported by science research grants from the China Manned Space Project with No.CMS-CSST-2021-B01the New Cornerstone Science Foundation through the XPLORER prizesupported by the ICG,SEPNet and the University of Portsmouth。
文摘The baryon acoustic oscillations (BAO) reconstruction plays a crucial role in cosmological analysis for spectroscopic galaxy surveys because it can make the density field effectively more linear and more Gaussian.The combination of the power spectra before and after the BAO reconstruction helps break degeneracies among parameters,then improves the constraints on cosmological parameters.It is therefore important to estimate the covariance matrix between pre-and post-reconstructed power spectra.In this work,we use perturbation theory to estimate the covariance matrix of the related power spectra multipoles,and check the accuracy of the derived covariance model using a large suite of dark matter halo catalogs at z=0.5.We find that the diagonal part of the auto covariance is well described by the Gaussian prediction,while the cross covariance deviates from the Gaussian prediction quickly when k>0.1 h Mpc^(-1).Additionally,we find the non-Gaussian effect in the nondiagonal part of the cross covariance is comparable to,or even stronger than,the pre-reconstruction covariance.By adding the non-Gaussian contribution,we obtain good agreement between analytical and numerical covariance matrices in the non-diagonal part up to k■0.15 h Mpc^(-1).The agreement in the diagonal part is also improved,bu still under-predicts the correlation in the cross covariance block.
