Cosmological constraints from the redshift dependence of the Alcock-Paczynski effect: Dynamical dark energy

We perform an anisotropic clustering analysis of 1,133,326 galaxies from the Sloan Digital Sky Survey (SDSS-III) Baryon Oscillation Spectroscopic Survey (BOSS) Data Release (DR) 12 covering the redshift range $0.15<z<0.69$. The geometrical distortions of the galaxy positions, caused by incorrect cosmological model assumptions, are captured in the anisotropic two-point correlation function on scales 6 – 40 $h^{-1}\mathrm{M}\mathrm{p}\mathrm{c}$. The redshift evolution of this anisotropic clustering is used to place constraints on the cosmological parameters. We improve the methodology of Li et al. 2016, to enable efficient exploration of high dimensional cosmological parameter spaces, and apply it to the Chevallier-Polarski-Linder parametrization of dark energy, $w=w_0+w_{a}z\mathrm{/}(1+z)$. In combination with the CMB, BAO, SNIa and $H_0$ from Cepheid data, we obtain \Omega_m = 0.301 \pm 0.008,\ w_0 = -1.042 \pm 0.067,\ and $w_a=-0.07\pm 0.29$ (68.3% CL). Adding our new AP measurements to the aforementioned results reduces the error bars by $\sim$30 – 40% and improves the dark energy figure of merit by a factor of $\sim$2. We check the robustness of the results using realistic mock galaxy catalogues.