Gershgorin Boris, Lvov Yuri V, Cai David
Department of Mathematical Sciences, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Phys Rev Lett. 2005 Dec 31;95(26):264302. doi: 10.1103/PhysRevLett.95.264302. Epub 2005 Dec 20.
We demonstrate via numerical simulation that in the strongly nonlinear limit the Beta-Fermi-Pasta-Ulam (Beta-FPU) system in thermal equilibrium behaves surprisingly like weakly nonlinear waves in properly renormalized normal variables. This arises because the collective effect of strongly nonlinear interactions effectively renormalizes linear dispersion frequency and leads to effectively weak interaction among these renormalized waves. Furthermore, we show that the dynamical scenario for thermalized Beta-FPU chains is spatially highly localized discrete breathers riding chaotically on spatially extended, renormalized waves.
我们通过数值模拟证明，在强非线性极限下，处于热平衡的贝塔 - 费米 - 帕斯塔 - 乌拉姆（Beta - FPU）系统的行为令人惊讶地类似于在适当重整化的正规变量中的弱非线性波。这是因为强非线性相互作用的集体效应有效地重整化了线性色散频率，并导致这些重整化波之间的有效弱相互作用。此外，我们表明，热化的Beta - FPU链的动力学场景是空间高度局域化的离散呼吸子在空间扩展的重整化波上混沌地传播。
