论文标题
在GROSS-PITAEVSKII模型中的波动溃疡级联的紧急各向同性
Emergent isotropy of a wave-turbulent cascade in the Gross-Pitaevskii model
论文作者
论文摘要
对称性的恢复是湍流最迷人的特性之一。我们报告了对具有各向异性强迫的大比塔维斯基（Gross-Pitaevskii）模型中各向同性的研究。受到最新实验的启发，我们研究了bose-Einstein凝结物在圆柱形盒中沿陷阱的对称轴驱动的圆柱盒中的动力学，这是通过空间均匀的力的。我们介绍了在动量分布$ n（\ boldsymbol {k}，t）$上定义的各向异性$ a（k，t）$的度量，并研究$ a（k，t）$和$ n（\ boldsymbol {k}，t）$的演变。随着系统达到稳态，由于大规模强迫，各向异性在低动量时大大降低。而$ n（\ boldsymbol {k}，t）$表现出自相似的级联正面传播，而$ a（k，t）$减少而没有这样的自相似动力学。最后，我们的数值计算表明，相对于驱动的振幅，稳态的各向同性是可靠的。
The restoration of symmetries is one of the most fascinating properties of turbulence. We report a study of the emergence of isotropy in the Gross-Pitaevskii model with anisotropic forcing. Inspired by recent experiments, we study the dynamics of a Bose-Einstein condensate in a cylindrical box driven along the symmetry axis of the trap by a spatially uniform force. We introduce a measure of anisotropy $A(k,t)$ defined on the momentum distributions $n(\boldsymbol{k},t)$, and study the evolution of $A(k,t)$ and $n(\boldsymbol{k},t)$ as turbulence proceeds. As the system reaches a steady state, the anisotropy, large at low momenta because of the large-scale forcing, is greatly reduced at high momenta. While $n(\boldsymbol{k},t)$ exhibits a self-similar cascade front propagation, $A(k,t)$ decreases without such self-similar dynamics. Finally, our numerical calculations show that the isotropy of the steady state is robust with respect to the amplitude of the drive.
