发表机构
Maharaja Agrasen University; SVKM’s NMIMS (Deemed to be University); GMN College（玛哈拉贾阿格萨尔大学; SVKM NMIMS（视为大学）; GMN学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究在线性f(R,T)引力框架下融入跑动真空场景，利用多观测数据集约束模型参数，证实其观测可行且热力学一致，为描述宇宙加速膨胀提供了理论替代方案。
AI 中文摘要
尽管ΛCDM模型取得了显著的观测成功，但暗能量和宇宙学常数的物理起源仍未得到解决，这推动了在修正引力理论中探索动力学真空场景。受跑动真空能量的量子场论描述启发，我们在线性f(R,T)=R+λT引力框架下研究了跑动真空宇宙学。与近期建立跑动真空能量与修正引力之间有效对应关系的研究不同，我们的方法将受量子场论启发的跑动真空场景直接融入f(R,T)框架，并考察其宇宙学含义。在空间平坦的Friedmann-Lemaître-Robertson-Walker时空中，我们得到了修正场方程的精确解析解，给出了哈勃参数的解析表达式。通过马尔可夫链蒙特卡罗分析，我们利用最新的Pantheon+SH0ES汇编、DESI重子声学振荡测量及其联合数据集对模型的自由参数进行了约束。经观测约束的模型成功再现了观测到的膨胀历史，与独立的宇宙计时仪测量结果一致，预测的宇宙年龄在当前观测范围内，且得到的有效状态方程与当前观测兼容。此外，statefinder和Om诊断表明，该模型在后期与ΛCDM场景吻合度高，而热力学第二定律在整个宇宙演化过程中始终成立。这些结果表明，所提出的框架为f(R,T)引力中的跑动真空宇宙学提供了观测上可行且热力学一致的实现方式，为描述当前加速膨胀的宇宙提供了一种有理论依据的替代方案。
英文摘要
Despite the remarkable observational success of the $Λ$CDM model, the physical origin of dark energy and the cosmological constant remain unresolved, motivating the exploration of dynamical vacuum scenarios within modified theories of gravity. Inspired by the quantum field theoretical description of running vacuum energy, we investigate a running vacuum cosmology in the framework of linear $f(R,T)=R+λT$ gravity. Unlike recent studies that establish an effective correspondence between running vacuum energy and modified gravity, our approach directly incorporates a quantum field theory motivated running vacuum scenario into the $f(R,T)$ framework and examines its cosmological implications. Exact analytical solutions of the modified field equations are obtained in a spatially flat Friedmann--Lemaître--Robertson--Walker spacetime, yielding an analytical expression for the Hubble parameter. The free model parameters are constrained using the latest Pantheon+SH0ES compilation, DESI baryon acoustic oscillation measurements, and their joint dataset through Markov Chain Monte Carlo analysis. The observationally constrained model successfully reproduces the observed expansion history, remains consistent with independent Cosmic Chronometer measurements, predicts an age of the universe within current observational bounds, and yields an effective equation of state compatible with current observations. Furthermore, the statefinder and $Om$ diagnostics indicate close agreement with the $Λ$CDM scenario at late times, while the generalized second law of thermodynamics remains valid throughout cosmic evolution. These results demonstrate that the proposed framework provides an observationally viable and thermodynamically consistent realization of running vacuum cosmology in $f(R,T)$ gravity, offering a theoretically motivated alternative for describing the present accelerated universe.
Comments29 pages, 11 figures
