We develop an improved Alcock-Paczynski (AP) test method that uses the redshift-space two-point correlation function (2pCF) of galaxies. Cosmological constraints can be obtained by examining the redshift dependence of the normalized 2pCF, which should not change apart from the expected small non-linear evolution. An incorrect choice of cosmology used to convert redshift to comoving distance will manifest itself as redshift-dependent 2pCF. Our method decomposes the redshift difference of the two-dimensional correlation function into the Legendre polynomials whose amplitudes are modeled by radial fitting functions. Our likelihood analysis with this 2-D fitting scheme tightens the constraints on Ωm and w by ∼40% compared to the method of Li et al. (2016, 2017, 2018) that uses one dimensional angular dependence only. We also find that the correction for the non-linear evolution in the 2pCF has a non-negligible cosmology dependence, which has been neglected in previous similar studies by Li et al.. With an accurate accounting for the non-linear systematics and use of full two-dimensional shape information of the 2pCF down to scales as small as 5h−1Mpc it is expected that the AP test with redshift-space galaxy clustering anisotropy can be a powerful method to constrain the expansion history of the universe.
@article{arxiv.1904.05503,
title = {Alcock-Paczynski Test with the Evolution of Redshift-Space Galaxy Clustering Anisotropy},
author = {Hyunbae Park and Changbom Park and Cristiano G. Sabiu and Xiao-dong Li and Sungwook E. Hong and Juhan Kim and Motonari Tonegawa and Yi Zheng},
journal= {arXiv preprint arXiv:1904.05503},
year = {2019}
}