Explore the intricate world of unbounded linear operators with “Unbounded Linear Operators: Theory and Applications.” This comprehensive volume, ideal for advanced undergraduates and graduate students, offers a systematic approach to operator theory in normed linear spaces, with a strong focus on applications to differential equations. Beginning with essential concepts of normed linear spaces and Hilbert space, the book meticulously builds the theory of unbounded operators. Discover key topics like strictly singular operators, perturbation theory with applications to ordinary differential operators, and the Dirichlet operator, showcasing the powerful connection between functional analysis and classical analysis. Written in a clear, readable style with minimal notation and abundant examples, this text provides a self-contained and accessible resource for mastering this crucial area of mathematics.