Saved in:
Bibliographic Details
Main Authors: Ye, Gen, Chudaykin, Anton, Bonvin, Camille, Kunz, Martin
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.12415
Tags: Add Tag
No Tags, Be the first to tag this record!
Table of Contents:
  • We present a non-parametric, model-independent reconstruction of the cosmological background and perturbation dynamics in non-minimally coupled theories of gravity. Within the Effective Field Theory of dark energy framework, we reconstruct the time-dependent cosmological constant, $Λ(t)$, and the non-minimal coupling function, $Ω(t)$, from cosmological data. To ensure stability, we apply a correlated smoothness prior that restricts the reconstruction to the space of sufficiently smooth functions. Using CMB, DESI BAO, Type Ia supernovae, CMB-ISW lensing cross-correlations, and large-scale 3x2pt DES Year 3 data, we find a $2.8σ$ hint for a non-minimal coupling. For the dark energy equation of state, our results indicate a preference for the existence of crossing of the phantom divide, $w_{DE}=-1$, at $z<0.8$. The non-minimal coupling effect stabilizes dark energy perturbations, providing a viable physical interpretation of the phantom crossing scenario. Our work paves the way for model-agnostic searches for signatures of modified gravity in cosmological data.