On exponentially small terms of solutions to nonlinear ordinary differential equations
The author considers a first-order system with a slowly-varying matrix and a small nonlinear part that depends on two times. The first one is a slowly-varying time. The nonlinear part is periodic in the second time. Combining the ideas of averaging method and frozen coefficients method the author finds a main part of the asymptotics of the solution on a large time interval.
scientific article; zbMATH DE number 818484