RT Journal Article T1 Representation and inequalities involving continuous linear functionals and fractional derivatives A1 Jornet, Marc A1 Nieto Roig, Juan José K1 Representation of functionals K1 Inequalities K1 Differintegral operators K1 Riemann-Liouville fractional calculus AB We investigate how continuous linear functionals can be represented in terms of generic operators and certain kernels (Peano kernels), and we study lower bounds for the operators as a consequence, in the space of square-integrable functions. We apply and develop the theory for the Riemann–Liouville fractional derivative (an inverse of the Riemann–Liouville integral), where inequalities are derived with the Gaussian hypergeometric function. This work is inspired by the recent contributions by Fernandez and Buranay (J Comput Appl Math 441:115705, 2024) and Jornet (Arch Math, 2024). PB Springer YR 2024 FD 2024-10-29 LK https://hdl.handle.net/10347/46490 UL https://hdl.handle.net/10347/46490 LA eng NO Jornet, M., & Nieto, J. J. (2025). Representation and inequalities involving continuous linear functionals and fractional derivatives. Advances in Operator Theory, 10(1). https://doi.org/10.1007/S43036-024-00397-8 NO The research of the author Juan J. Nieto was supported by the Agencia Estatal de Investigación (AEI) of Spain Grant PID2020-113275GB-I00 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe”, by the “European Union” and Xunta de Galicia, grant ED431C 2023/12 for Competitive Reference Research Groups (2023–2026). DS Minerva RD 19 may 2026