Functional Analysis: An Introduction to Metric Spaces, Hilbert Spaces, and Banach Algebras - Paperbackby Joseph Muscat (Author) This textbook provides an introduction to functional analysis suitable for lecture courses to final year undergraduates or beginning graduates. Starting from the very basics of metric spaces, the book adopts a self contained approach to Banach spaces and operator theory that covers the main topics, including the spectral theorem, the Gelfand transform, and Banach algebras. Various applications, such as least squares