What question did this study set out to answer?

To observationally test a quintessence model with exponential potential and establish its viability against conventional dark energy scenarios.

April 27, 2026Open Access

Cosmological dynamics of exponential quintessence constrained by BAO, cosmic chronometers, and DES-SN5YR/Pantheon^+ data

Key Points

To observationally test a quintessence model with exponential potential and establish its viability against conventional dark energy scenarios.
Utilized Markov Chain Monte Carlo framework to analyze high-precision datasets including Cosmic Chronometers and Baryon Acoustic Oscillations.
Performed model comparison using Akaike Information Criterion to assess statistical relevance against standard Lambda CDM model.
Investigated energy conditions to confirm physical viability and analyzed Statefinder diagnostics.
Tight constraints on cosmological parameters (H_0, Omega_m0, eta_0, gamma) significantly align with observational data.
Exponential quintessence model effectively describes the universe, maintaining total equation of state greater than -1.
Showed stable predictions for Hubble parameter and distance modulus, remaining consistent with Lambda CDM.

Abstract

Abstract We perform a comprehensive observational test of a canonical quintessence model driven by an exponential potential, motivated by its emergence in higher-dimensional theories, string-inspired scenarios, and modified gravity. Using a Markov Chain Monte Carlo framework, we constrain the model with the latest high-precision observational datasets–Cosmic Chronometers, Baryon Acoustic Oscillation, Pantheon ^+ +, and DES-SN5YR Type Ia Supernovae. The combined data significantly tighten the parameter bounds on (H₀, ₌䃐, ₀, ) (H 0, Ω m 0, η 0, γ) and yield predictions for the Hubble parameter H (z), the distance modulus (z) μ (z), and the scaled comoving angular diameter distance that remain in excellent agreement with observations and closely follow the Λ CDM baseline. In addition, an information-theoretic model comparison based on the Akaike Information Criterion shows that the exponential quintessence model remains statistically comparable with the Λ CDM scenario, despite the penalty associated with its additional parameters. The model naturally reproduces the transition from matter domination to late-time acceleration, maintains total equation of state ₓ₎ₓ > -1 ω tot > - 1 as expected for canonical scalar fields, and provides an age of the universe consistent with Planck 2018. The Statefinder diagnostics show trajectories approaching the Λ CDM fixed point, while allowing small observable departures. Energy condition analysis confirms physical viability, with only the Strong Energy Condition violated at late times, as required for acceleration. Overall, our results show that quintessence with an exponential potential provides a stable, observationally consistent alternative to Λ CDM. Using the latest high-precision datasets, we obtain some of the most stringent constraints on this exponential-potential quintessence model, reaffirming its viability as a compelling dynamical explanation for dark energy.

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