Lifting cosmic degeneracy within a single quasar survey

Abstract

In the almost Friedmann-Lemaˆıtre model of the Universe, the density parameter, Ωm, and the cosmo- logical constant, ΩΛ, measure curvature. Several linearly degenerate relations between these two parameters have recently been measured. Here, large scale structure cor- relations at ∼ 100 − 150 h−1 Mpc are found in the co- moving three-dimensional separations of redshift z ≈ 2 quasars. These function as a comoving standard rod of length LLSS ≈ 130 ± 10 h−1 Mpc. A local maximum in the correlation function at ≈ LLSS/2 also appears to be significant. By combining separate radial and tangential standard ruler analyses, the lifting of the Ωm − ΩΛ linear degeneracy within a single data set is demonstrated for the first time.