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TESTING March 05, 2026

Observational and Thermodynamic aspects of one-dimensional Dark Energy EoS parametrization models

Authors

Anirban Chatterjee, Yungui Gong

Abstract

We examine the observational viability and physical implications of the Gong-Zhang (GZ) dark--energy equation-of-state parametrizations using exclusively late-time cosmological probes. Two one-dimensional parametrization models, GZ-Type~I and GZ-Type~II, are constrained with Type~Ia supernovae (Union3, Pantheon+SH0ES, and DES-SN5YR), DESI baryon acoustic oscillations, and cosmic chronometer measurements of $H(z)$. Bayesian inference combined with information-criteria diagnostics shows that both parametrizations provide competitive alternatives to $Λ$CDM, while the GZ-Type~II model is consistently favored, exhibiting reduced parameter degeneracy and stronger Jeffreys-scale support. Beyond background expansion tests, we employ configuration entropy as a thermodynamically motivated probe of structure formation. We demonstrate that the entropy-production rate sensitively traces the impact of dynamical dark energy on late-time gravitational clustering while preserving standard early-time behavior. Our results establish the Gong-Zhang framework as a physically transparent and observationally consistent extension of $Λ$CDM, with configuration entropy providing a complementary diagnostic of late-time cosmic acceleration.

Metadata

arXiv ID: 2603.05009
Provider: ARXIV
Primary Category: gr-qc
Published: 2026-03-05
Fetched: 2026-03-06 14:20

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