arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2008.12394nlin.PSnlin.CD
收藏

具有平坦色散带的守恒非线性链中紧呼吸子的稳定性

Stability of compact breathers in translationally-invariant nonlinear chains with flat dispersion bands

Nathan Perchikov, O. V. Gendelman

摘要:

本文讨论了紧凑的振荡状态(紧凑的呼吸者)在平行不变的晶格与平坦的色散带。即使在线性近似下,紧呼吸子也出现在这样的系统中。如果相互作用是非线性的,但符合平带对称性,紧呼吸解存在,但可以失去其稳定性的某些参数值。作为基准的非线性势,我们使用的$β$ -FPU(费米-帕斯塔-乌拉姆)和振动碰撞模型。数值上观察到的稳定性损失发生通过干草叉或霍普夫分叉。稳定性的损失可以发生通过两个定性不同的机制-通过内部不稳定的基本晶格元素,或通过相互作用的紧凑的呼吸与晶格的线性通带。前一种情况对于高振幅呼吸波更为典型,而后一种情况对于低振幅呼吸波更为典型。对于高振幅的情况下,洞察紧凑模式的性质损失的稳定性得到诉诸分段线性系统的限制,其中的相互作用是由保守的影响。这个问题需要详细的反省到分段线性(影响)系统的可积性及其与光滑系统的关系。提出了一种基于所研究机制的传感器的想法。

英文摘要:

The paper addresses compact oscillatory states (compact breathers) in translationally-invariant lattices with flat dispersion bands. The compact breathers appear in such systems even in the linear approximation. If the interactions are nonlinear, but comply with the flat-band symmetry, the compact breather solutions exist, but can lose their stability for certain parameter values. As benchmark nonlinear potentials, we use the $β$-FPU (Fermi-Pasta-Ulam) and vibro-impact models. Loss of stability is numerically observed to occur through either pitchfork or Hopf bifurcations. The loss of stability can occur through two qualitatively different mechanisms -- through internal instability in the basic lattice elements, or through interaction of the compact breather with the linear passband of the lattice. The former scenario is more typical for high-amplitude breathers, and the latter -- for low amplitudes. For the high-amplitude case, insights into the nature of compact-mode loss-of-stability are obtained by resorting to the limit of a piecewise-linear system, where interactions are represented by conservative impacts. This issue calls for detailed introspection into integrability of piecewise-linear (impacting) systems and their relation to the smooth system. An idea for a sensor based on the studied mechanisms is suggested.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑