This book presents recent advances in the estimation and control of nonlinear fractional‑order systems, viewed through the lens of fixed‑point theory. Fractional‑order models have gained importance for their ability to represent memory, hereditary properties, and complex system behavior with greater fidelity than classical integer‑order approaches. Yet the nonlinear nature of these systems introduces analytical and numerical challenges.

The authors address these challenges by developing a unified framework grounded in fixed‑point theory, offering practical tools for stability analysis, numerical approximation, control design, and state estimation. Each chapter explains key concepts using a consistent structure and concludes with real‑world examples, including applications in engineering, physics, and biological systems.

Designed for graduate students, researchers, and engineers working in control theory, applied mathematics, and nonlinear dynamics, this book provides a self‑contained and accessible introduction to contemporary methods for analyzing and controlling nonlinear fractional‑order systems.

Rafael Martínez‑Guerra earned a B.Sc. in Physics and Mathematics from the National Polytechnic Institute (IPN), Mexico City, and an M.Sc. in Automatic Control from the Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav). He also obtained an M.Sc. in Mathematics and Automatic Control from École des Mines, Paris, and a Ph.D. from the Universidad Autónoma Metropolitana in 1996.

He is a Researcher in the Automatic Control Department at Cinvestav and has been a Level 3 Member of the National System of Researchers since 1992. He is the author or co‑author of more than 92 journal articles, over 150 conference contributions, and 10 books. His research interests include nonlinear systems, differential‑geometric and differential‑algebraic methods, fractional‑order observers, fault detection and diagnosis, secure communications, synchronization, and chaos.

Lorenz Oliva‑Gonzalez obtained a B.Sc. in Control and Automation from the National Polytechnic Institute (IPN), Mexico City. He holds an M.Sc. (2022) and a Ph.D. (2026) in Automatic Control from the Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav). He is the author or co‑author of 11 research articles published in international journals and conference proceedings. His research interests include fractional calculus, real and complex analysis, nonlinear dynamics, chaos theory, control theory, and numerical methods.