发表机构
Centre for Cosmology, Astrophysics and Space Science (CCASS), GLA University; Department of Mathematics, Netaji Subhas University of Technology（宇宙学、天体物理学和空间科学中心，GLA大学; 数学系，Netaji Subhas理工大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过参数化体粘性并利用哈勃数据和Pantheon+超新星样本进行MCMC拟合，验证了粘性FLRW模型能解释宇宙加速膨胀，且与ΛCDM一致，同时揭示了哈勃张力。
AI 中文摘要
在本研究中，我们探讨了体粘性在由尘埃主导的空间平坦弗里德曼-勒梅特-罗伯逊-沃克（FLRW）宇宙演化中的作用。我们将体粘性参数化为p_tilde = -3[l + m(H'(t) + H^2) + nH^2]H，推导了修正的爱因斯坦场方程，并将其改写为红移z的函数。利用46个哈勃参数测量值和包含1701个超新星的Pantheon+数据集，我们通过χ2最小化估计模型参数（H0, l, m, n），并使用马尔可夫链蒙特卡洛（MCMC）模拟进行优化。分析给出过渡红移z_t = 0.585和当前减速参数q0 = -0.705，与ΛCDM模型一致。宇宙当前年龄估计为t0 = 14.5734 Gyr。我们从哈勃数据集获得H0 = 68 km/s/Mpc，从Pantheon+获得约73 km/s/Mpc。这些结果展示了晚期和早期宇宙H0测定之间的哈勃张力。我们进一步研究了状态方程参数ω(z)、能量密度ρ(z)和压力p(z)的演化。态finder诊断（r,s）显示了在不同时期对ΛCDM的偏离和趋近。结果强调了体粘性在描述宇宙加速膨胀中的潜在作用，并为研究宇宙学模型提供了有用的框架。
英文摘要
In this study, we investigate the role of bulk viscosity in the evolution of a spatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) universe dominated by dust. We parameterize the bulk viscosity as p_tilde = -3[l + m(H'(t) + H^2) + nH^2]H, derive the modified Einstein field equations, and reformulate them in terms of redshift z. Using 46 Hubble parameter measurements and the Pantheon+ compilation of 1701 supernovae, we estimate the model parameters (H0, l, m, n) through chi2 minimization and refine them using Markov chain Monte Carlo (MCMC) simulations. The analysis gives a transition redshift z_t = 0.585 and a present deceleration parameter q0 = -0.705, consistent with Lambda CDM. The present age of the universe is estimated as t0 = 14.5734 Gyr. We obtain H0 = 68 km/s/Mpc from the Hubble datasets and approximately 73 km/s/Mpc from Pantheon+. These results illustrate the Hubble tension between late- and early-universe determinations of H0. We further investigate the evolution of the equation-of-state parameter omega(z), energy density rho(z), and pressure p(z). Statefinder diagnostics (r,s) demonstrate deviations from and convergence toward Lambda CDM at different epochs. The results highlight the potential role of bulk viscosity in describing the accelerated expansion of the universe and provide a useful framework for studying cosmological models.
Comments23 pages, 8 figures
Journal refIndian J Phys, Published online 4 july2026
DOI：10.1007/s12648-026-04115-3
