無所不在的拉格朗日 - Lagrangian Everywhere
revision control
Flow $\phi_t$ 定義: $x_t \triangleq \phi_t\left(x_0\right)$, 顯然 $t=0 \to x_0 = \phi_0\left(x_0\right)$ $\phi_t(x)$ 必須可微分且可逆。
Excellent lectures!!!!: https://www.youtube.com/watch?v=8mxCNMJ7dHM&list=PL0H3pMD88m8XPBlWoWGyal45MtnwKLSkQ