论文标题
各向同性媒体中的飞溅
Splashes in isotropic media
论文作者
论文摘要
在线性响应理论的框架内，将解释培养基对突然局部扰动（“飞溅”）的反应（“飞溅”）。在这一理论中，介质的集体激发的干扰引起了轰动，结果是由它们的相位和组速度之间的相互作用以及后者的迹象决定的。飞溅的显着特征由相位和组速度的极值存在控制：组速度给出了新波前核定或现有的点消失的点的扩展速率，而相位速度则决定了波浪线的大型时间膨胀速率。如果组速度在光谱范围内为负，并且在其中占据最小值，则在飞溅中会存在收敛的波前。这些结果与对几种实验可行的设置的研究有关，例如由于小卵石或雨滴引起的深水表面上的飞溅，在二维电子气体中飞溅，这是由于短电压脉冲在扫描型隧道显微镜的尖端上施加的短电压脉冲，或者是在隧道示意图中的刺激，或者在隧道中的泡沫飞溅，或者是在繁重的bubluid bublon中造成了繁殖的$^4}。具体而言，后者的总特征由五个极端速度确定。此外，由于存在负组速度频谱范围，因此超级流体$^{4}中的某些波沿线正在融合。
The response of a medium to a sudden localized perturbation (a "splash") will be explained for isotropic media within the framework of linear response theory. In this theory splashes result from the interference of the collective excitations of the medium, with the outcome determined by the interplay between their phase and group velocities as well as the sign of the latter. The salient features of splashes are controlled by the existence of extremal values of the phase and the group velocities: the group velocity gives the expansion rate of the locus of the points where new wavefronts nucleate or existing ones disappear, while the phase velocity determines the large-time expansion rate of a group of wavefronts. If the group velocity is negative in a spectral range and takes on a minimal value within it, then converging wavefronts will be present in the splash. These results are relevant to the studies of several experimentally viable setups, such as a splash on the surface of deep water due to a small pebble or a raindrop, a splash in the two-dimensional electron gas caused by a short voltage pulse applied with the tip of a scanning tunneling microscope, or a bulk splash in superfluid $^{4}He$ due to formation of an electron bubble. Specifically, the gross features of the latter are determined by five extremal velocities. Additionally, due to the existence of a negative group velocity spectral range, some of the wavefronts in superfluid $^{4}He$ splash are converging.
