Speaker: Yong-Seon Song

Abstract:

We analyze the clustering of large scale structure in the Universe in a model independent method and accounting for anisotropic effects along and transverse to the line of sight. The Baryon Oscillation Spectroscopy Survey Data Release 9 (or 11) provides an excellent sample of 500,000 galaxies, allowing determination of the Hubble expansion $H$, angular distance $D_A$, and growth rate $\gth$ at an effective redshift of $z=0.57$. After careful bias and convergence studies of the effects from small scale clustering, we find that cutting transverse separations below 40 Mpc/$h$ delivers robust results while smaller scale data leads to bias due to unmodeled nonlinear and velocity effects. The converged results are in agreement with concordance $\Lambda$CDM cosmology, general relativity, and minimal neutrino mass, all at the 68\% confidence level. We also present results separately for the northern and southern hemisphere sky, finding a slight tension in the growth rate, but within 68\% CL.