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arXiv · 2608.29718

Testing $f(Q)$ Gravity with Logarithmic Equation of State Using Latest Cosmological Data

Chaymae Karam·Dalale Mhamdi·Taoufik Ouali·Rachid Ahl Laamara·Mohamed Bennai
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Abstract

In this paper, we investigate the late-time accelerated expansion of the Universe in power law $f(Q)$ gravity, where a logarithmic dark energy parametrization is considered: $\omega_{de}(z)=\omega_0+\omega_1\ln(1+z)$. This description gives a smooth deviation from a constant equation of state within the complete range of redshifts. We obtain an analytical expression for the Hubble parameter and we use a Markov Chain Monte Carlo to compare the model with the most recent observational data obtained from Pantheon$^+$ Type Ia supernovae, Baryon Acoustic Oscillation measurements from the second data release (DR2) of the Dark Energy Spectroscopic Instrument, and Cosmic Chronometers. We then perform a statistical comparison between our model and the standard $\Lambda$CDM model using the Akaike Information Criterion and the Bayesian Information Criterion. From our results, we conclude that the use of logarithmic parametrization in the $f(Q)$ gravity model $f(Q)=Q+6\gamma H_0^2\left(\frac{Q}{Q_0}\right)^n$ is a valid and more flexible alternative to standard dark energy models, as it provides a richer phenomenology at low redshifts.

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Chaymae Karam, Dalale Mhamdi, Taoufik Ouali, Rachid Ahl Laamara, Mohamed Bennai. 2026-08-30. Testing $f(Q)$ Gravity with Logarithmic Equation of State Using Latest Cosmological Data. https://arxiv.org/abs/2608.29718

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