相对论流体中流体动力学框架、输运系数与流体动力学模式之间的对应关系
Correspondence between hydrodynamic frames, transport coefficients, and hydrodynamic modes in relativistic fluids
浏览论文内容
中文总结 AI 辅助
该研究推导了Eckart与Landau-Lifshitz框架的精确变换关系，发现二者热导率存在焓依赖关系、声衰减系数一致，指出输运系数的框架依赖性仅源于耗散效应的不同分解，为相关研究明确指定流体动力学框架提供了依据。
中文摘要 AI 辅助
流体动力学框架的选择会直接影响相对论耗散流体动力学中输运系数的数值。我们推导了Eckart框架与Landau-Lifshitz框架之间的精确变换关系，表明二者的热导率由一个与焓相关的因子相联系。利用由Boltzmann核子气体物态方程描述的重子丰沛相对论流体，我们发现Landau-Lifshitz热导率相较于Eckart热导率被抑制，且二者的差值随温度和重子化学势的增大而增加。对声传播的线性分析表明，两个框架中的声衰减系数保持一致，证实了物理可观测量的框架不变性。我们的结果显示，输运系数的框架依赖性仅反映耗散效应在热流与扩散流之间的不同分解方式， underlying的输运物理保持不变。这些发现强调，在比较重离子碰撞、格点QCD和动理学理论计算得到的输运系数时，明确指定流体动力学框架的重要性。
英文摘要
The choice of hydrodynamic frame directly influences the numerical values of transport coefficients in relativistic dissipative hydrodynamics. We derive the exact transformation between the Eckart and Landau--Lifshitz frames and show that their thermal conductivities are related by an enthalpy-dependent factor. Using a baryon-rich relativistic fluid described by a Boltzmann nucleon gas equation of state, we find that the Landau--Lifshitz thermal conductivity is suppressed relative to the Eckart conductivity, with the difference increasing with temperature and baryon chemical potential. A linearized analysis of sound propagation demonstrates that the sound attenuation coefficient remains identical in both frames, confirming the frame invariance of physical observables. Our results show that the frame dependence of transport coefficients reflects only the different decomposition of dissipative effects into heat-flow and diffusion currents, while the underlying transport physics remains unchanged. These findings underscore the importance of specifying the hydrodynamic frame when comparing transport coefficients from heavy-ion collisions, lattice QCD, and kinetic-theory calculations.
