Modified gravity interpretation of the evolving dark energy in light of DESI data
Jul 2, 20241 page
Published in:
- Phys.Rev.D 110 (2024) 12, 123524
- Published: Dec 15, 2024
e-Print:
- 2407.02558 [astro-ph.CO]
DOI:
- 10.1103/PhysRevD.110.123524 (publication)
View in:
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Abstract: (APS)
The Dark Energy Spectroscopic Instrument (DESI) collaboration has recently released measurements of baryon acoustic oscillation (BAO) from the first year of observations. A joint analysis of DESI BAO, cosmic microwave background (CMB), and Type Ia supernovae (SNe Ia) probes indicates a preference for time-evolving dark energy. We evaluate the robustness of this preference by replacing the DESI distance measurements at with the Sloan Digital Sky Survey (SDSS) BAO measurements in a similar redshift range. Assuming the model, we find an evolution of the dark energy equation of state parameters consistent with . Our analysis of statistics across various BAO datasets shows that DESI’s preference for evolving dark energy is primarily driven by the two luminous red galaxy (LRG) samples at and , with the latter having the most significant impact. Taking this preference seriously, we study a general Horndeski scalar-tensor theory, which provides a physical mechanism to safely cross the phantom divide, . Utilizing the effective field theory of dark energy and adopting the background cosmological model, we derive constraints on the parameters and at 68% CL from Planck CMB, Planck and Atacama Cosmology Telescope (ACT) CMB lensing, DESI BAO, and , showing good consistency with the standard model. The modified gravity model gives results discrepant with at the level, while for it is at , based on the best-fit values. We conclude that modified gravity offers a viable physical explanation for DESI’s preference for evolving dark energy.Note:
- 10+1 pages, 5 figures, 3 tables; v2: model selection analyses added, matched version accepted by Phys. Rev. D
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Figures(5)
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