1. Hahn-Banach Theorem
1.1. The extension theorem
1.2. Hyperplane separation of convex sets
1.3. Applications
1.3.1 Extension of positive linear functionals
1.3.2 Lagrange multipliers of convex programming problems
2. Weak and weak * topologies
2.1. Weak convergence and weak compactness of unit ball in reflexive Banach spaces
2.2. Weak* convergence and weak* sequential compactness—Helly’s Theorem
2.3. Banach-Alaoglu Theorem
2.4. Applications
2.4.1. Approximation of the delta-function by continuous functions
2.4.2. Approximate quadrature
2.4.3. Existence of PDE via Galerkin’s method
3. General spectral theory
3.1. Spectral radius and Gelfand’s theorem
3.2. Functional calculus, spectral mapping theorem
3.3. Spectral decomposition/separation theorem
3.4. Isolated eigenvalues
3.4.1 Algebraic multiplicity
3.4.2 Laurent expansion of the resolvent operator near isolated eigenvalue
3.4.3 Stability of a finite set of isolated eigenvalues under small operator perturbation
3.5. Spectrum of the adjoint operator
3.6. The case of unbounded but closed operators
4. Compact operators and Fredholm operators
4.1. Riesz-Schauder theory
4.2. Hilbert-Schmidt theorem, min-max characterization of eigenvalues
4.3. Positive compact operators: Krein-Rutman theorem (for the special case of Banach space C(Q), where Q is a
compact Hausdorff space)
4.4. Fredholm operators
4.4.1 Characterization of Fredholm operators, pseudoinverse
4.4.2 Fredholm index: index of product of two operators, constancy of index under small or compact
perturbation
4.4.3 Essential spectrum of a bounded operator, and its constancy under compact perturbation
4.5. Applications
4.5.1. Second order elliptic operators
4.5.2. Non-local diffusion operators
4.5.3. Toeplitz operators
5. Spectral theory of bounded symmetric, normal and unitary operators
5.1. The spectrum of symmetric operators
5.2. Functional calculus for symmetric operators
5.3. Spectral resolution of symmetric operators
5.4. Absolutely continuous, singular, and point spectra
5.5. The spectral representation of symmetric operators
5.6. Spectral resolution of normal operators
5.7. Spectral resolution of unitary operators
5.8. Examples
6. Unbounded self-adjoint operators
6.1. Spectral resolution via Cayley transform
6.2. The extension of unbounded symmetric operators, deficiency indices
6.3. The Friedrichs extension
6.4. Examples
7. Semigroups of operators
7.1. Strongly continuous one-parameter semigroups
7.2. The generation of semigroups: Hille-Yosida theorem
7.3. Exponential decay of semigroups
7.4. Examples: semigroups defined by parabolic equations, and by nonlocal diffusion equations