发表机构
Jamia Millia Islamia（贾米亚米利娅伊斯兰大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究对ΛCDM、CPL等四种宇宙学模型做观测与热力学分析，重构热力学量发现暗能量的热力学相变具有模型依赖性，为暗能量研究提供互补探针。
AI 中文摘要
我们对四种宇宙学模型（ΛCDM、CPL、MPL及三参数MmAH参数化）开展观测与热力学分析。所有动力学模型相比ΛCDM的拟合度均有提升，Δχ²约为6-6.5，其中MPL拟合效果最佳，MmAH仍具可行性。尽管贝叶斯证据因ΛCDM复杂度更低而略微偏向它，但结合当前观测，动力学暗能量模型仍是有竞争力的替代方案。我们随后在观测约束宇宙学模型中重构热力学量，拓展了此前的理论研究。最佳拟合热容重构显示，仅在ΛCDM中，与二级热力学相变相关的发散点恰好对应减速-加速转变；而动力学暗能量模型中，该发散点出现在不同红移处，表明这种对应关系并非普遍存在。所有模型在0≤z≤1范围内均满足广义热力学第二定律，海森矩阵分析揭示相变处存在瞬时不稳定性；不过，晚期热力学稳定性具有模型依赖性，CPL与MPL保持稳定，而ΛCDM和MmAH无法同时满足两个稳定性条件。这些结果表明，在观测约束宇宙学模型中重构的热力学性质可作为暗能量的互补探针，热力学相变是本质上依赖于模型的现象。
英文摘要
We perform an observational and thermodynamic analysis of four cosmological models $Λ$CDM, CPL, MPL, and the three-parameter MmAH parametrization. All dynamical models improve the fit relative to $Λ$CDM, with $Δχ^2 \sim 6$-$6.5$, with MPL providing the best fit, while MmAH remains viable. Although Bayesian evidence mildly favors $Λ$CDM due to its lower complexity, the dynamical dark energy models remain competitive alternatives given current observations. We then reconstruct thermodynamic quantities within observationally constrained cosmological models, extending previous theoretical studies. The bestfit heat capacity reconstruction indicates that the divergence associated with a second order thermodynamic phase transition coincides with the deceleration-acceleration transition only in $Λ$CDM, whereas for the dynamical dark energy models it occurs at distinct redshifts, suggesting that this coincidence is not universal. The generalized second law is satisfied for all models over $0 \le z \le 1$, while the Hessian analysis reveals a transient instability at the phase transition; however, the late time thermodynamic stability is model dependent, with CPL and MPL remaining stable and $Λ$CDM and MmAH failing to satisfy both stability conditions simultaneously. These results show that thermodynamic properties reconstructed within observationally constrained cosmological models provide a complementary probe of dark energy, with the thermodynamic phase transition emerging as an intrinsically model dependent phenomenon.
Journal refPhys. Lett. B 881 (2026) 140879
DOI：10.1016/j.physletb.2026.140879
