Resolving the Planck-DESI tension by nonminimally coupled quintessence

Abstract

The Planck measurement of the cosmic microwave background (CMB) has established the $\hat{I}›$-cold-dark-matter ($\hat{I}›$CDM) model as the concordant model along with other observations. However, recent measurements of baryon acoustic oscillations (BAO) from the Dark Energy Spectroscopic Instrument (DESI) have renewed the matter fraction $\hat{I}{\text{c◯}}_{\mathrm{m}}$ tension between Planck-$\hat{I}›$CDM and DESI-$\hat{I}›$CDM. Directly reconciling this CMB-BAO tension with a dynamical DE in Chevallier-Polarski-Linder (CPL) parametrization seems to imply a crossing of the equation-of-state (EOS) through $w=-1$ at low redshifts. In this paper, we resolve this $\hat{I}{\text{c◯}}_{\mathrm{m}}$ tension by allowing for the DM nonminimally coupled to gravity via a quintessence field. This non-minimal coupling is preferred over $3\ddot{I}ƒ$ confidence level. Consequently, even though the usual effective EOS of the coupled quintessence apart from the standard CDM part never crosses but always is above $w=-1$, a misidentification with the $w_0{w}_a$CDM model would exactly fake such a crossing behavior, and the tensions on neutrino mass and growth rate in the $\hat{I}›$CDM model are also relieved in our model as a result of the resolved $\hat{I}{\text{c◯}}_{\mathrm{m}}$ tension.

v4, 16 pages, 9 figures, 3 tables, version accepted for publication in Physical Review D; v5, to match the published version