The VIMOS Public Extragalactic Redshift Survey (VIPERS) - Ωm0 from the galaxy clustering ratio measured at z ~ 1

We use a sample of about 22,000 galaxies at 0.65< z< 1.2 from the VIMOS public extragalactic redshift survey (VIPERS) public data release 1 (PDR-1) catalogue, to constrain the cosmological model through a measurement of the galaxy clustering ratioηg,R. This statistic has favourable properties, which is defined as the ratio of two quantities ch aracterizing the smoothed density field in spheres of a given radius R: the value of its correlation function on a multiple of this scale,ξ(nR), and its varianceσ 2 (R). For suffi ciently large values of R, this is a universal number, which captures 2-point clustering information independently of the linear bias and linear redshift-space distortions of th e specific galaxy tracers. In this paper, we discuss how to extend the application ofηg,R to quasi-linear scales and how to control and remove observational selection effects, which are typical of redshift surveys as VIPERS, in detail. We verify the accuracy and effi ciency of these procedures using mock catalogues that match the survey selection process. These results show the robustness ofηg,R to non-linearities and observational effects, which is related to its very definition as a ratio of quantities that are similarly a ffected.