发表机构
VIT-AP University; Pacif Institute of Cosmology and Selfology (PICS)（维特-AP大学; 帕西夫宇宙学与自学生研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在 $f(T,\mathcal{L}_m)$ 引力框架下，用粘性重子流体模型，通过贝叶斯MCMC分析多类观测数据，约束参数并验证了宇宙加速膨胀及精质态演化。
AI 中文摘要
我们在 $f(T,\mathcal{L}_m)$ 引力框架下，通过使用宇宙流体的重子状态方程，研究了粘性流体的宇宙动力学。利用修正的弗里德曼方程构建了一个解析的哈勃模型。然后，使用 $H(z)$、Pantheon+SH0ES、DESI DR II BAO 和宇宙微波背景数据集，在贝叶斯马尔可夫链蒙特卡罗分析中约束其自由参数。获得的拟合最佳值给出了哈勃常数和重子状态方程参数的物理上可行的估计。基于约束参数，我们检查了减速参数、有效状态方程、暗能量状态方程、有效压力和粘性压力随红移的依赖性。虽然减速参数揭示了宇宙如何从初始减速状态演化到当前的加速膨胀，但两个状态方程参数在晚期持续处于精质区域。此外，在整个宇宙演化过程中，粘性压力和有效压力保持为负值。所提出的粘性 $f(T,\mathcal{L}_m)$ 宇宙学模型的观测可行性得到了估计的哈勃常数的支持，其值与独立宇宙学观测的结果吻合良好。
英文摘要
We examine the cosmological dynamics of a viscous fluid within the framework of $f(T,\mathcal{L}_m)$ gravity by using a barotropic equation of state for cosmic fluid. The modified Friedmann equations are used to construct an analytical Hubble model. Then $H(z)$, Pantheon+SH0ES, DESI DR II BAO, and Cosmic Microwave Background datasets are used in a Bayesian Markov Chain Monte Carlo analysis to constrain its free parameters. Physically viable estimations of the Hubble constant and barotropic equation of state parameter are given by the obtained best-fit values. Based on the constrained parameters, we examine the redshift dependence of deceleration parameter, effective equation of state, dark energy equation of state, the effective pressure and viscous pressure quantities. While the deceleration parameter reveals how the universe evolved from an initially decelerating state to its present accelerating expansion, both equation of state parameters persist in the quintessence regime in the late epoch. Moreover, throughout the cosmic evolution, the viscous and effective pressures stay negative. The observational viability of the suggested viscous $f(T,\mathcal{L}_m)$ cosmological model is supported by the estimated Hubble constant, whose values agree well with the results from independent cosmological observations.
