The Direct Measurement of Gravitational Potential Decay Rate at Cosmological Scales. II. Improved Dark Energy Constraint from z ≤ 1.4

Abstract

The gravitational potential decay rate (DR) is caused by the cosmic acceleration of the Universe, providing a direct probe into the existence of dark energy (DE). We present measurements of DR and explore its implications for DE models using the DR9 galaxy catalog of the Dark Energy Spectroscopic Instrument (DESI) imaging surveys and the Planck cosmic microwave background maps. Our analysis includes six redshift bins within the range of 0.2 ≤ z < 1.4 and achieves a total significance of 3.1σ, extending the DR measurements to a much higher redshift compared to Dong et al., which focused on 0.2 ≤ z < 0.8. Other improvements involve addressing potential systematics in the DR-related measurements of correlation functions, including imaging systematics and magnification bias. We explore the constraining power of DR on both the wCDM model and the w0waCDM model. We find that the addition of DR can significantly improve the DE constraints, over Sloan Digital Sky Survey baryon acoustic oscillation (BAO) data alone or the PantheonPlus supernovae (SNe) compilation alone, although it shows only a modest improvement for DESI BAO. In the wCDM model, all three probes—DR, DESI BAO, and SNe—favor w = −1. For the w0waCDM, while DESI BAO prefers w0 > −1 and wa < 0, the SNe Ia and DR data constrain and . Namely, SNe Ia and DR data have no preference on dynamical DE over Λ.