The direct measurement of gravitational potential decay rate at cosmological scales II -- Improved dark energy constraint from $z\le1.4$

TL;DR

This study measures the decay rate of gravitational potential at high redshifts using galaxy and CMB data, providing improved constraints on dark energy models and confirming the cosmological constant as consistent with observations.

Contribution

It extends the measurement of gravitational potential decay rate to higher redshifts and demonstrates its significant role in constraining dark energy parameters.

Findings

DR measurement extends to z<1.4 with 3.1σ significance.

Adding DR improves dark energy constraints beyond BAO or SNe alone.

Results favor a cosmological constant (w=-1) over dynamical dark energy models.

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 Data Release 9 galaxy catalog of DESI imaging surveys and the Planck cosmic microwave background maps. Our analysis includes six redshift bins within the range of $0.2\le z<1.4$ and achieves a total significance of 3.1$\sigma$, extending the DR measurements to a much higher redshift comparing to Dong et al. (2022), which focused on $0.2\le z<0.8$. 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 both the $w$CDM model and the $w_0w_a$CDM model. We find that, the addition of DR can significantly improves DE constraints, over Sloan Digital Sky Survey baryon acoustic oscillation (BAO) data alone or PantheonPlus supernovae (SNe) compilation alone, although it shows only a modest improvement for DESI BAO. In the $w$CDM model, all three probes-DR, DESI BAO and SNe-favor $w=-1$. For the $w_0w_a$CDM, while DESI BAO prefers $w_0>-1$ and $w_a<0$, SNe Ia and DR data constrain $w_0=-0.94^{+0.11}_{-0.13}$ and $w_a=-0.22^{+0.57}_{-0.97}$. Namely SNe Ia and DR data has no preference on dynamical dark energy over $\Lambda$.