Late-time dark energy dynamics in f(Q) gravity: A data-driven analysis
Abstract
The increasing precision and complementarity of late-time cosmological observations provide new opportunities to test modified gravity against the observed expansion history of the universe. The combination of DESI DR2 BAO measurements with cosmic chronometers (CC) and independent Type Ia supernova compilations provides a data-driven test of cosmic acceleration. Motivated by this progress, we investigate late-time dark energy dynamics in symmetric teleparallel f(Q) gravity by adopting the power-law form f(Q)=βQm+1 and characterizing cosmic evolution through the effective equation of state (EoS) parameter. The model is constrained using CC, DESI DR2 BAO and three independent Type Ia supernova compilations, namely Pantheon+, DES-SN5YR and Union3. The inferred Hubble constant values are mutually consistent, yielding H0=67.60+1.60−1.66, 67.08+1.66−1.61 and 68.16+1.46−1.43 km s−1 Mpc−1, respectively. Statistically, the proposed f(Q) model yields lower χ2min values and is favored by the AIC for all dataset combinations, whereas the BIC favors ΛCDM for the CC + DESI DR2 + Pantheon+ and CC + DESI DR2 + DES-SN5YR combinations and indicates no meaningful preference between the two models for the CC + DESI DR2 + Union3 dataset combinations. The reconstructed EoS indicates quintessence-like behavior, while the negative deceleration parameter confirms the current accelerated expansion. The transition from deceleration to acceleration occurs within 0.680≤ zt≤0.745. Higher-order cosmographic parameters and the Statefinder and Om(z) diagnostics consistently support this quintessence-like behavior, with the Statefinder trajectories approaching the ΛCDM fixed point in the far future. Overall, the power-law f(Q) model provides a viable and competitive description of late-time cosmic acceleration.
Related
- Hybrid Expansion Cosmology in f(T) Gravity: Late-Time Evolution and Observational Bounds
- Cosmological evolution and late-time attractors in axion-monopole interacting dark energy
- Late-time cosmological constraints on three holographic dark energy models with DESI DR2 BAO and Type Ia supernovae
- Early- and late-time constraints on Wald-Gauss-Bonnet topological dark energy and implications for the H0 and S8 tensions
- A Multi-Axion Ladder Across Cosmic History: From Inflation, BBN, and Early Dark Energy to Late-Time Accelerated Expansion
BibTeX
@misc{singh2026latetime,
title = {{Late-time dark energy dynamics in $f(Q)$ gravity: A data-driven analysis}},
author = {Kshetrimayum Govind Singh and Kangujam Priyokumar Singh},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.01650},
eprint = {2609.01650},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.01650},
}
RIS
TY - UNPB
TI - Late-time dark energy dynamics in f(Q) gravity: A data-driven analysis
AU - Kshetrimayum Govind Singh
AU - Kangujam Priyokumar Singh
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.01650
UR - https://arxiv.org/abs/2609.01650
AB - The increasing precision and complementarity of late-time cosmological observations provide new opportunities to test modified gravity against the observed expansion history of the universe. The combination of DESI DR2 BAO measurements with cosmic chronometers (CC) and independent Type Ia supernova compilations provides a data-driven test of cosmic acceleration. Motivated by this progress, we investigate late-time dark energy dynamics in symmetric teleparallel f(Q) gravity by adopting the power-law form f(Q)=βQ^m+1 and characterizing cosmic evolution through the effective equation of state (EoS) parameter. The model is constrained using CC, DESI DR2 BAO and three independent Type Ia supernova compilations, namely Pantheon+, DES-SN5YR and Union3. The inferred Hubble constant values are mutually consistent, yielding H_0=67.60^+1.60_−1.66, 67.08^+1.66_−1.61 and 68.16^+1.46_−1.43 km s^−1 Mpc^−1, respectively. Statistically, the proposed f(Q) model yields lower χ^2_min values and is favored by the AIC for all dataset combinations, whereas the BIC favors ΛCDM for the CC + DESI DR2 + Pantheon+ and CC + DESI DR2 + DES-SN5YR combinations and indicates no meaningful preference between the two models for the CC + DESI DR2 + Union3 dataset combinations. The reconstructed EoS indicates quintessence-like behavior, while the negative deceleration parameter confirms the current accelerated expansion. The transition from deceleration to acceleration occurs within 0.680≤ z_t≤0.745. Higher-order cosmographic parameters and the Statefinder and Om(z) diagnostics consistently support this quintessence-like behavior, with the Statefinder trajectories approaching the ΛCDM fixed point in the far future. Overall, the power-law f(Q) model provides a viable and competitive description of late-time cosmic acceleration.
ER -