Entropic Chaplygin-Gas cosmology and late-universe tension diagnostics
Abstract
We investigate an entropic generalized Chaplygin-gas (gCg) cosmology in which a single dark fluid accounts for both dark matter and dark energy. We constrain the model using DESI baryon acoustic oscillations, redshift-space-distortion measurements, compressed Planck 2018 distance and lensing information, and Type Ia supernova likelihoods with PantheonPlus+SH0ES (PPS) and DES--Dovekie. For Planck+DESI+RSD+PPS, the entropic gCg model yields a Hubble constant of H0=68.64±0.52 km s−1 Mpc−1 and the amplitude of matter fluctuations parameter of S8=0.797±0.021, compared with H0=67.31±0.28 km s−1 Mpc−1 and S8=0.809±0.021 in ΛCDM. The simultaneous upward shift in H0 and downward shift in S8 occurs in the directions required for a partial alleviation of both tensions. We also show that when PPS is replaced by DES--Dovekie, the parameter shifts are smaller, the best-fit improvement is negligible, and the Bayesian evidence favours ΛCDM. Thus, the entropic gCg model provides a potentially interesting simultaneous shift of the Hubble constant and the matter-clustering amplitude, but its statistical support depends on the adopted supernova likelihood.
Related
- The gravitational Olbers’ paradox and the entropic accelerating universe
- On entropic cosmology, late-time acceleration and the quantum bounce
- Theoretical consistency and observational constraints on entropic cosmology
- The Euler Universe: A Relational Phase Framework for Cosmology — Construction, Philosophy, and Stress-Testing of the Spiral U(θ) = e^((λ+i)θ)
- Theoretical Consistency and Observational Constraints on Entropic Cosmology
BibTeX
@misc{kulhkampa2026entropic,
title = {{Entropic Chaplygin-Gas cosmology and late-universe tension diagnostics}},
author = {Kelvis A. Kulhkampa and Carlos H. Coimbra-Araújob and Abraão J. S. Capistrano and Luiz A. Cabral and José A. P. F. Marão},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2607.22802},
eprint = {2607.22802},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2607.22802},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Entropic Chaplygin-Gas cosmology and late-universe tension diagnostics
AU - Kelvis A. Kulhkampa
AU - Carlos H. Coimbra-Araújob
AU - Abraão J. S. Capistrano
AU - Luiz A. Cabral
AU - José A. P. F. Marão
PY - 2026
DA - 2026/10/20
PB - arXiv
DO - 10.48550/arxiv.2607.22802
UR - https://arxiv.org/abs/2607.22802
AB - We investigate an entropic generalized Chaplygin-gas (gCg) cosmology in which a single dark fluid accounts for both dark matter and dark energy. We constrain the model using DESI baryon acoustic oscillations, redshift-space-distortion measurements, compressed Planck 2018 distance and lensing information, and Type Ia supernova likelihoods with PantheonPlus+SH0ES (PPS) and DES--Dovekie. For Planck+DESI+RSD+PPS, the entropic gCg model yields a Hubble constant of H_0=68.64±0.52 km s^−1 Mpc^−1 and the amplitude of matter fluctuations parameter of S_8=0.797±0.021, compared with H_0=67.31±0.28 km s^−1 Mpc^−1 and S_8=0.809±0.021 in ΛCDM. The simultaneous upward shift in H_0 and downward shift in S_8 occurs in the directions required for a partial alleviation of both tensions. We also show that when PPS is replaced by DES--Dovekie, the parameter shifts are smaller, the best-fit improvement is negligible, and the Bayesian evidence favours ΛCDM. Thus, the entropic gCg model provides a potentially interesting simultaneous shift of the Hubble constant and the matter-clustering amplitude, but its statistical support depends on the adopted supernova likelihood.
ER -