necessaryandsufficientconditionsfortheexistenceofequilibriuminabstractnonautonomousfunctionaldifferentialequations

In this article, we aim to establish necessary and sufficient conditions that guarantee the existence of equilibria and continuous equilibria for the continuous skew-product semiflow induced by a class of abstract non-autonomous finite-delay functional differential equations without any monotone conditions assumed. A minimal set is constructed in terms of which necessary and sufficient conditions for a continuous equilibrium to exist are also obtained. Several illustrative examples are employed to demonstrate our results