论文标题
Gubser流的流体动力吸引子
Hydrodynamic attractors for Gubser flow
论文作者
论文摘要
使用分布函数的角矩层次结构，在松弛时间近似中求解了Boltzmann方程。我们的解决方案是针对正在经历Gubser流动的方位角对称径向扩展的增强不变的保形系统。将我们在各种阶的无限方程组截断后获得的矩与精确的动力学溶液的解。过渡的动力学是通过固定点的存在来描述的，固定点描述了系统从早期无碰撞的自由流到中间时间的流体动力学状态的演变，并在后期回到了自由流。在这些固定点之间的插值中发现了吸引子解决方案。研究了矩与相对论粘性流体动力学的各种近似值的关系。
The Boltzmann equation is solved in the relaxation time approximation using a hierarchy of angular moments of the distribution function. Our solution is obtained for an azimuthally symmetric radially expanding boost-invariant conformal system that is undergoing Gubser flow. The solution of moments that we get after truncating the infinite set of equations at various orders is compared to the exact kinetic solution. The dynamics of transition is described by the presence of fixed points which describes the evolution of the system from an early time collisionless free streaming to the hydrodynamic regime at intermediate times and back to free streaming at late times. The attractor solution is found for various orders of moments as an interpolation between these fixed points. The relation of moments to various approximations of relativistic viscous hydrodynamics is investigated.
