Pseudo almost periodic solutions for equation with piecewise constant argument

By using the roughness theory of exponential dichotomies and the contraction mapping, some sufficient conditions are obtained for the existence and uniqueness of pseudo almost periodic solution of the above differential equation with piecewise constant argument d x d t = A ( t ) x ( t ) + ∑ j = 0 r A j ( t ) x ( [ t − j ] ) + g ( t , x ( t ) , x ( [ t ] ) , … , x ( [ t − r ] ) ) .