Sur les systèmes différentiels à coefficients périodiques

Abstract

Abstract In this work, we are interested in studying the differential equation with periodic coeffi- cients of the form : ˙x = A(t)x, x ∈ Rn. where A(t + T) = A(t). We will define some initial concepts related to differential systems with periodic coeffi- cients, which show us the existence of periodic solutions thanks to two important theories, Which allow us to convert these periodic systems into fixed systems thanks to a simple transformation.