3 papers
physics.plasm-ph2025
Functional perturbation theory under axisymmetry: Simplified formulae and their uses for tokamaks
Wenyin Wei, Liang Liao, Alexander Knieps +3
In strictly axisymmetric configurations of tokamaks, field-line tracing reduces from a three-dimensional ODE system to a two-dimensional one, where Poincaré-Bendixson theorem appl…
nlin.CD2024
Deformation of invariant tori under perturbation
Wenyin Wei, Jiankun Hua, Alexander Knieps +1
This study extends the functional perturbation theory~(FPT) of dynamical systems, which was initially developed for investigating the shifts of magnetic field line trajectories wit…
math.DS2024
On the shifts of orbits and periodic orbits under perturbation and the change of Poincaré map Jacobian of periodic orbits
Wenyin Wei, Alexander Knieps, Yunfeng Liang
Periodic orbits and cycles, respectively, play a significant role in discrete- and continuous-time dynamical systems (i.e. maps and flows). To succinctly describe their shifts when…