Reaffirming the Cosmic Acceleration without Supernovae and the Cosmic Microwave Background
Xiaolin Luo, Zhiqi Huang, Qiyue Qian, Lu Huang
Abstract
Abstract Recent discussions about supernova magnitude evolution have raised doubts about the robustness of the late-universe acceleration. In a previous letter, Huang did a null test of the cosmic acceleration by using a Parameterization based on the cosmic Age (PAge), which covers a broad class of cosmological models including the standard Λ cold dark matter model and its many extensions. In this work, we continue to explore the cosmic expansion history with the PAge approximation. Using baryon acoustic oscillations ( without a CMB prior on the acoustic scale), gravitational strong lens time delay, and passively evolving early galaxies as cosmic chronometers, we obtain ≳ 4 σ detections of cosmic acceleration for both flat and nonflat PAge universes. In the nonflat case, we find a novel ≳3 σ tension between the spatial curvatures derived from baryon acoustic oscillations and strong lens time delay. Implications and possible systematics are discussed.