“…Over the past few years, fractional functional differential equations (FrFDEs) in both finite and infinite dimensional spaces have been widely investigated in the literature by many researchers [1,2,13,16,24,28,29,30,35,36]. These studies are strongly motivated from the fact that FrFDEs are effective tools in the modeling various processes, phenomena arising from physics, biology, economics, engineering and other applied sciences, where the current state of such evolutionary processes depends on the past state [3,6,33].…”