A joint 2 and 3point clustering analysis of the VIPERS PDR2 catalogue at z 1: breaking the degeneracy of cosmological parameters
Abstract
We measure the galaxy two and threepoint correlation functions at z = [0.5, 0.7] and z = [0.7, 0.9], from the Public Data Release 2 (PDR2) of the VIMOS Public Extragalactic Redshift Survey (VIPERS). We model the two statistics including a nonlinear oneloop model for the twopoint function and a treelevel model for the threepoint function, and perform a joint likelihood analysis. The entire process and nonlinear corrections are tested and validated through the use of the 153 highly realistic VIPERS mock catalogues, showing that they are robust down to scales as small as 10 $h^{1} \, \mathrm{Mpc}$. The mocks are also adopted to compute the covariance matrix that we use for the joint two and threepoint analysis. Despite the limited statistics of the two (volumelimited) subsamples analysed, we demonstrate that such a combination successfully breaks the degeneracy existing at twopoint level between clustering amplitude σ_{8}, linear bias b_{1}, and the linear growth rate of fluctuations f. For the latter, in particular, we measure $f(z=0.61)=0.64^{+0.55}_{0.37}$ and f(z = 0.8) = 1.0 ± 1.0, while the amplitude of clustering is found to be σ_{8}(z = 0.61) = 0.50 ± 0.12 and $\sigma _8(z=0.8)=0.39^{+0.11}_{0.13}$. These values are in excellent agreement with the extrapolation of a Planck cosmology.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 October 2021
 DOI:
 10.1093/mnras/stab2205
 arXiv:
 arXiv:2106.12581
 Bibcode:
 2021MNRAS.507.1184V
 Keywords:

 galaxies: statistics;
 largescale structure of Universe;
 cosmology: observations;
 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 18 pages, 12 figures, 4 tables. Submitted to MNRAS. Comments welcome