标题： 具有非零背景电荷情况下Israel-Stewart理论的线性稳定性分析 显示英文标题

标题： Linear stability analysis of Israel-Stewart theory in the case of a nonzero background charge

摘要： 在文献[Phys. Rev. D 102 (2020) 116009]中研究了在净电荷扩散存在的情况下Israel-Stewart理论的线性稳定性，该研究针对的是无相互作用粒子的经典无质量气体的情况。 然而，在那项工作中仅考虑了零净电荷背景。 在这项工作中，我们将该研究扩展到非零背景电荷的情况。 我们发现这实际上会导致电荷扩散系数的数值发生变化，具体而言，当背景电荷趋于无穷大时，该系数最多可以变为零背景电荷时值的四倍。 我们还通过在剪切应力与净电荷扩散耦合项之间的电荷扩散系数平面上进行系统的参数研究，扩展了文献[Phys. Rev. D 102 (2020) 116009]中的分析。 在这个平面上，我们确定了解保持稳定且因果以及变得非因果和/或不稳定的区域。 显示英文摘要

摘要： Linear stability of Israel-Stewart theory in the presence of net-charge diffusion was investigated in [Phys.~Rev.~D 102 (2020) 116009] for the case of a massless, classical gas of noninteracting particles. However, in that work only a vanishing net-charge background was considered. In this work, we extend that study to the case of a nonvanishing background charge. We find that this effectively results in a change of the numeric value of the charge-diffusion coefficient, in a way that when the background charge goes to infinity, this coefficient can become at most four times its value at zero background charge. We also extend the analysis of [Phys.~Rev.~D 102 (2020) 116009] by performing a systematic parameter study in the plane of charge-diffusion coefficient vs.\ the coupling term between shear-stress and net-charge diffusion. In this plane, we identify regions where the solutions remain stable and causal and where they become acausal and/or unstable.