Trapping region

In applied mathematics, a trapping region of a dynamical system is a region such that every trajectory that starts within the trapping region will move to the region's interior and remain there as the system evolves.

More precisely, given a dynamical system with flow $\phi _{t}$ defined on the phase space $D$, a subset of the phase space $N$ is a trapping region if it is compact and $\phi _{t}(N)\subset \mathrm {int} (N)$ for all $t>0$.