发表机构
Universidad Mayor; Universidad de Santiago de Chile（马约尔大学; 智利圣地亚哥大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在动力学系统重构框架下，于幺模引力中系统构建并分类扩散宇宙学，确定了相关不动点与标度解，实现无需宇宙学常数的晚期加速膨胀，提供了扩散宇宙学的全局探索方法。
AI 中文摘要
我们在动力学系统重构框架下研究幺模引力中的宇宙学扩散模型。通过将扩散 sector 的对数斜率视为可逆动力学变量，可从宇宙学演化的相空间结构系统地重构扩散函数。在此条件下，我们确定了系统物理上可容许的不动点，识别出与幂律扩散 sector 相关的新型物质-扩散标度解，以及无需显式宇宙学常数项即可驱动晚期加速膨胀的纯扩散主导构型。随后将不动点附近的局域行为扩展至完整宇宙学演化，提供了探索扩散宇宙学全局含义的框架。除渐近不动点结构外，我们还开发了基于扩散斜率动力学演化的重构形式，允许宇宙历史中不同扩散 regime 间插值的轨迹。我们的结果为直接从相空间动力学构建和分类幺模引力中可行的扩散宇宙学建立了系统框架。
英文摘要
We investigate cosmological diffusion models in unimodular gravity within a dynamical systems reconstruction framework. By treating the logarithmic slope of the diffusion sector as an invertible dynamical variable, the diffusion function can be systematically reconstructed from the phase-space structure of the cosmological evolution. Under these conditions, we determine the physically admissible fixed points of the system, identifying novel matter--diffusion scaling solutions associated with power-law diffusion sectors, as well as purely diffusion-dominated configurations capable of driving late-time accelerated expansion without requiring an explicit cosmological constant term. The local behavior around the fixed points is then extended to the full cosmological evolution, providing a framework to explore the global implications of diffusion cosmologies. Beyond the asymptotic fixed-point structure, we further develop a reconstruction formalism based on the dynamical evolution of the diffusion slope, allowing for trajectories interpolating between different diffusion regimes during the cosmic history. Our results establish a systematic framework for constructing and classifying viable diffusion cosmologies in unimodular gravity directly from the phase-space dynamics.
Comments14 pages, 2 figures. Submitted to EPJC
