Cosmological constraints from the power spectrum of eBOSS quasars

We present the effective-field theory (EFT-)based cosmological full-shape analysis of the anisotropic power spectrum of eBOSS quasars at the effective redshift zeff = 1.48. We perform extensive tests of our pipeline on simulations, paying particular attention to the modeling of observational systematics, such as redshift smearing, fiber collisions, and the radial integral constraint. Assuming the minimal ? cold dark matter model, and fixing the primordial power spectrum tilt and the physical baryon density, we find the Hubble constant H0 = (66.7 +/- 3.2) km s-1 Mpc-1, the matter density fraction omega m = 0.32 +/- 0.03, and the late-time mass fluctuation amplitude sigma 8 = 0.95 +/- 0.08. These measurements are fully consistent with the Planck cosmic microwave background results. Our eBOSS quasar S8 posterior, 0.98 +/- 0.11, does not exhibit the so-called S8 tension. Our work paves the way for systematic full-shape analyses of quasar samples from future surveys like DESI.