发表机构
São Paulo State University (UNESP), Institute of Geosciences and Exact Sciences（圣保罗州立大学（UNESP）地球科学与精确科学学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过迭代映射和分岔分析，发现非线性Walecka模型存在周期倍增混沌路径及虾形稳定岛，其危机现象可指示核物质宏观重排，影响中子星状态方程。
AI 中文摘要
本文研究了非线性Walecka模型（NLWM）的动力学性质，该模型也称为量子强子动力学（QHD），通过核子-介子相互作用为描述核物质提供了相对论框架。虽然原始的线性模型成功捕捉了核物质的定性特征，但它高估了核压缩性；因此，采用在标量场（$\sigma$）中包含三次和四次自相互作用项的非线性扩展，以更好地与实验数据吻合。通过将自洽的有效质量方程视为迭代映射，本研究探索了周期轨道和混沌区域等复杂行为的出现。利用非线性动力学的工具，包括返回映射和分岔图，我们通过周期倍增级联刻画了通往混沌的路径，并识别了参数空间混沌区域内“虾形”稳定等周期岛的存在。此外，我们讨论了这些发现的物理意义，提出危机现象和结构收敛可能作为标量平均场宏观重排的动力学特征，可能影响致密核物质在极端环境（如中子星）中的稳定性及状态方程（EOS）。
英文摘要
This paper investigates dynamical properties of the Nonlinear Walecka Model (NLWM), also known as Quantum Hadrodynamics (QHD), which provides a relativistic framework for describing nuclear matter through nucleon-meson interactions. While the original linear model successfully captures qualitative features of nuclear matter, it overestimates nuclear compressibility; consequently, nonlinear extensions incorporating cubic and quartic self-interaction terms in the scalar field $(σ)$ are employed to achieve better agreement with experimental data. By treating the self consistent effective-mass equation as an iterative mapping, the study explores the emergence of complex behaviors such as periodic orbits and chaotic regimes. Using tools from nonlinear dynamics, including return maps and bifurcation diagrams, we characterize routes to chaos via period doubling cascades and identify the presence of "shrimps" stable isoperiodic islands within chaotic regions of the parameter space. Furthermore, we discusses the physical implications of these findings, suggesting that crisis phenomena and structural convergence may serve as dynamical signatures of macroscopic rearrangements in the scalar mean field, potentially influencing the stability and equation of state (EOS) of dense nuclear matter in extreme environments like neutron stars.
