This is a 23-lecture course, with each lecture being about 60-90 minutes, given at MIT in person by Casey Rodriguez. It gives an introduction to functional analysis.

Functional analysis helps us study and solve both linear and nonlinear problems posed on a normed space that is no longer finite-dimensional, a situation that arises very naturally in many concrete problems. Topics include normed spaces, completeness, functionals, the Hahn-Banach Theorem, duality, operators; Lebesgue measure, measurable functions, integrability, completeness of Lp spaces; Hilbert spaces; compact and self-adjoint operators; and the Spectral Theorem.

  1. Basic Banach Space Theory
  2. Bounded Linear Operators
  3. Quotient Spaces, the Baire Category Theorem and the Uniform Boundedness Theorem
  4. The Open Mapping Theorem and the Closed Graph Theorem
  5. Zorn’s Lemma and the Hahn-Banach Theorem
  6. The Double Dual and the Outer Measure of a Subset of Real Numbers
  7. σ-algebras
  8. Lebesgue Measurable Subsets and Measure
  9. Lebesgue Measurable Functions
  10. Simple Functions
  11. The Lebesgue Integral of a Non-negative Function and Convergence Theorems
  12. Lebesgue Integrable Functions, the Lebesgue Integral and the Dominated Convergence Theorem
  13. Lp Space Theory
  14. Basic Hilbert Space Theory
  15. Orthonormal Bases and Fourier Series
  16. Fejer’s Theorem and Convergence of Fourier Series
  17. Minimizers, Orthogonal Complements and the Riesz Representation Theorem
  18. The Adjoint of a Bounded Linear Operator on a Hilbert Space
  19. Compact Subsets of a Hilbert Space and Finite-Rank Operators
  20. Compact Operators and the Spectrum of a Bounded Linear Operator on a Hilbert Space
  21. The Spectrum of Self-Adjoint Operators and the Eigenspaces of Compact Self-Adjoint Operators
  22. The Spectral Theorem for a Compact Self-Adjoint Operator
  23. The Dirichlet Problem on an Interval

These videos are of a lecture course by Casey Rodriguez at the Massachusetts Institute of Technology in 2021, and made available as part of its OpenCourseWare initiative.