Periodic Solutions to Partial Neutral Functional Differential Equations in Admissible Spaces on a Half-Line

We prove the existence and uniqueness of periodic solutions to partial neutral function differential equation of the form ∂ F u t ∂ t = A ( t ) F u t + g ( t , u t ) , t ∈ [ 0 , ∞ ) , on a Banach space X , where the operator-valued function t ↦ A ( t ) and the nonlinear delay operator g ( t , v ) are both T -periodic with respect to t , whereas g is φ -Lipschitz with respect to v for φ belonging to an admissible space. Then, in the case that the family ( A ( t )) t ≥ 0 generates an evolution family having an exponential dichotomy, we apply our abstract results to study the existence, uniqueness of periodic solutions. We also prove the conditional stability, and the existence of local stable manifolds around such periodic solutions.