Approximations on Timescales Longer Than \(1/ \varepsilon \)
摘要
In some cases it is possible to establish a longer timescale of validity of approximation. If the average over time of the system \(\dot {x} = \varepsilon f(t, x)\) vanishes, the approximation can in the periodic case be extended to \(1/\varepsilon ^2\) . Another important case arises if the averaged equation contains a solution that is exponentially attracting. In such a case we can extend the timescale to the whole time axis.