ABSTRACT
Let us show that the same results are valid for singularly perturbed differential operators with periodic or almost periodic coefficients for sufficiently small values of parameter ε.
Consider a singularly perturbed differential operator
L(ε)x = ε dx
dt −A(t)x, (8.1)
where ε > 0 is a small parameter, A(t) is a square matrix of order n with its elements being almost periodic functions.