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arXiv · 2606.23563

Unifying the Dark Sector with the New Generalized Chaplygin Gas: Observational Constraints

Abdulla Al Mamon·Andronikos Paliathanasis·Subhajit Saha
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Abstract

In light of recent cosmological observations, we examine a generalized Chaplygin gas model with a redshift-dependent exponent as a framework for describing the dark energy and dark matter content of the Universe. Specifically, we treat this fluid as a single unified component and test it against late-time background observational data. We employ Type Ia supernova data, cosmic chronometers, and baryon acoustic oscillations from the second data release of the Dark Energy Spectroscopic Instrument. We perform a Bayesian analysis for parameter estimation and compare the model with $\Lambda$CDM. We find that the generalized Chaplygin gas provides systematically higher values of the combined likelihood; nevertheless, once the larger number of free parameters is taken into account, both the Bayesian evidence and the Akaike Information Criterion suggest that the model is statistically indistinguishable from $\Lambda$CDM.

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Abdulla Al Mamon, Andronikos Paliathanasis, Subhajit Saha. 2026-06-22. Unifying the Dark Sector with the New Generalized Chaplygin Gas: Observational Constraints. https://doi.org/10.1002/prop.70127

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