标题： 磁场和化学势诱导的各向异性与全息QCD中$Q\bar{Q}$对的框架相关混沌的相互作用 显示英文标题

标题： Interplay of magnetic field and chemical potential induced anisotropy and frame dependent chaos of a $Q\bar{Q}$ pair in holographic QCD

摘要： 我们研究了磁场和化学势在从全息原理得出的量子色动力学（QCD）禁闭弦中混沌动力学出现中的作用。一个早期开发的自下而上的爱因斯坦-麦克斯韦-标量引力模型，很好地模仿了QCD的特征，被采用。通过庞加莱截面和李雅普诺夫指数获得了关于混沌的定性信息。我们在能量上不利的弦构型中发现了混沌的迹象，这些构型更靠近视界，而在远离视界的能量上有利的弦构型中没有观察到混沌。我们的结果在分析中所考虑的框架中表现出相当强的依赖性。在弦框架中，化学势和磁场在抑制弦与磁场平行和垂直方向上的混沌动力学方面起作用。同时，在爱因斯坦框架中，当弦的方向与磁场垂直/平行时，磁场分别抑制/增强混沌动力学，而化学势则增强了两种取向下的混沌动力学。报告的李雅普诺夫指数与模型参数空间中的MSS界限的经典类比一致，并且我们在两种框架中都发现它总是满足的。 显示英文摘要

摘要： We investigate the role of both magnetic field and chemical potential on the emergence of chaotic dynamics in the QCD confining string from the holographic principle. An earlier developed bottom-up model of Einstein-Maxwell-dilaton gravity, which mimics QCD features quite well, is used. The qualitative information about the chaos is obtained using the Poincar\'{e} sections and Lyapunov exponents. We find signatures of chaos in energetically disfavored string configurations, that are closer to the horizon, whereas no chaos is observed in energetically favored string configurations that are away from the horizon. Our results depend quite strongly on the frame we consider in the analysis. In the string frame, the chemical potential and the magnetic field suppress the chaotic dynamics in both parallel and perpendicular orientations of the string with respect to the magnetic field. Meanwhile, in the Einstein frame, the magnetic field suppresses/enhances the chaotic dynamics when the string is orientated perpendicular/parallel to the magnetic field, while the chemical potential enhances the chaotic dynamics for both orientations. The reported Lyapunov exponents are consistent with a classical analogue of the MSS bound in the parameter space of the model and we find it to be always satisfied in both frames.