Nonlinear Hilfer fractional systems of higher order: Existence and finite controllability analysis
This paper investigates the existence and finite-approximate controllability of higher-order nonlinear Hilfer fractional integrodifferential systems governed by Hilfer fractional derivatives of order 1 < ϱ < 2 with nonlocal initial conditions in Hilbert spaces. An appropriate notion of a mild solution is established by means of the higher-order Hilfer fractional resolvent family. Under suitable hypotheses, the existence of mild solutions is proved by applying Schaefer’s fixed-point theorem. Furthermore, the finite-approximate controllability of the proposed system is established by combining the controllability of the corresponding linear system with a variational approach. The obtained results extend the existing finite-approximate controllability theory for Hilfer fractional systems to the higher-order setting. Finally, an illustrative example is presented to demonstrate the applicability of the theoretical results.

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