Prerequisite proofs
The selected lessons state which results they use. The links below include programme proofs and external research materials. An external reference does not replace a programme proof. The vector-valued integration and tensor identification needed here are proved in the first lesson.
Measure and integration
- Haar measure, modular function, inversion and compact support estimates
- Measure and Hilbert space tools for Haar integration
C*-Fourier and Plancherel proofs
- Theorem 2.1: C*(G)=C*_r(G)=C0(dual G), both norms sup|Fourier f|
- Theorem 2.1: complete continuous character spectrum of L1(G), compact-open topology
- Theorem 3.2: uniform Fourier-image density in C0(dual G)
- Lemma 1.1: individual L1 vector carrier and L1-valued convolution integral
- Proposition 1.1: finite complex Radon measures determined by positive-sign character transforms
- Theorem 2.1: continuous positive-type function has unique finite positive representing measure
- Theorem 2.1: dual Haar construction and B1 inversion
- Proposition 3.1: primal Haar c dx gives reciprocal dual c^-1 dxi
- Theorem 1.1: onto L2 Fourier unitary agreeing with the integral on L1 intersect L2
- Proposition 2.1(1): L1 convolution on L2 conjugates to Fourier multiplication
- Lemma 2.2: inverse integral on L1 intersect L2 of the dual
- Theorem 3.1: Fourier algebra equals L2*L2 as actual continuous functions
- Corollary 3.3: compact continuous convolution is transform of B1 vector
- Theorem 2.1: evaluation alpha G is a topological group isomorphism onto the bidual
- Proposition 3.1: bidual Haar equals pushforward dx and Fdual F = reflection
- Corollary 4.2: Fourier injectivity on finite Radon measures and L1
- Lemma 5.1: each L2 vector has a sigma-compact open subgroup carrier
- Vector integration lemma VI1-VI3: Bochner norm/Fubini and onto L2(G) tensor K identification for arbitrary K
- Theorem 5.1(4)-(7): Radon-product Tonelli/Fubini at support qualifications
- Theorem 6.2: onto Radon-product L2 Hilbert tensor unitary
- Proposition 3.1(4): Cc density in finite-p Haar spaces
- Proposition 7.2: open sigma-compact subgroup from a compact identity neighborhood
- Proposition 13.7: canonical finite-p comparison, with differing global measures
- Theorems 2.1-2.2: sequence convergence without countability hypotheses
- Theorems 3.1-3.2: Holder, Minkowski, completeness and simple approximation
Spectral and von Neumann foundations for logarithmic products
- Emmanuel Kowalski: Spectral theory in Hilbert spaces. Theorem 3.1, Proposition 4.38, Theorem 4.42 and Corollary 4.43; the lesson supplies the arbitrary-Hilbert-space extension.
- Orr Shalit: Introduction to von Neumann algebras, Lecture 7. Definitions 8–10 and Theorem 11, for the concrete predual and vector-series topology.
- Vaughan F. R. Jones: Von Neumann algebras. Theorem 3.2.2 and Corollary 3.2.3, for the general bicommutant theorem.
Spectral and complex-analysis foundations for power strips
- Emmanuel Kowalski: Spectral theory in Hilbert spaces. Theorems 3.1 and 4.42: the separable spectral theorem, with the arbitrary-Hilbert reduction proved in the lesson.
- Alexandre Vizeff: Complex analysis, Lecture 6. Section 3: bounded-domain harmonic maximum principle.
- Alexandre Vizeff: Complex analysis, Lecture 9. Cauchy integral theorem and formula, with positively oriented contours.
- Alexandre Vizeff: Complex analysis, Lecture 10. Cauchy estimates for Taylor coefficients.
- Alexandre Vizeff: Complex analysis, Lecture 11. Rectangular Morera theorem and proof.
Derivation and innerness foundations
- Section 3, adjoining an identity and its complete C*-norm
- Section 2, Neumann series and inverse estimates; preceding absolute-product lemma
- CF Section 1: explicit choice convention, maximal principle and norm Hahn–Banach proofs
- Theorems 2.1–2.2 and Corollary 2.3; real and complex Hahn–Banach
- Theorem 3.1; complete-metric Baire
- Lemma 4.1 and Theorem 4.2; Banach operator space and arbitrary-family uniform boundedness
- Theorem 5.1, Corollary 5.2 and Theorem 5.3; open mapping, inverse and closed graph
- Theorem 3.1, using Tychonoff Theorem 2.3 in preceding section
- Theorems 5.1 and 5.3; continuous calculus and nonunital form
- Propositions 7.2–7.3; Jordan decomposition and unitary spans; positive cone is in §8
- Theorem 11.4 and Corollary 11.5; arbitrary approximate identity nets
- Theorem 3.1, including (5) commutation with the commutant
- Theorem 4.4; bounded selfadjoint spectral measure and uniqueness
- Theorem 6.1; arbitrary bounded monotone nets
- Theorem 8.1; normal/unitary bounded spectral calculus for L34 small corners
- Theorem 4.4; bicommutant characterization
- Proposition 7.2; polar decomposition inside a von Neumann algebra
- Theorem 9.4; predual of an arbitrary sigma-weakly closed subspace
- Corollaries 11.4–11.5 and following positive-map criterion
- Proposition 3.1, Proposition 3.5, Lemma 4.2; arbitrary joins, central supports, left supports
- Corollary 2.8; Hermitian normal-functional decomposition
Faithful-state core foundations
- OA-FLOW course project: Local Fourier and closed-form foundations for the state core Local proof with its stated mathematical prerequisites.
- OA-FLOW course project: Faithful normal GNS representations and their topologies Local proof with its stated mathematical prerequisites.
- OA-FLOW course project: Full left-Hilbert-algebra domains and the unchanged closed involution Local proof with its stated mathematical prerequisites.
- OA-FLOW course project: MF-06: narrow scalar and vector integration bridge Local proof with its stated mathematical prerequisites.
- OA-FLOW course project: Modular covariance through positive multipliers and operator averages Local proof with its stated mathematical prerequisites.
Operator and Banach foundations
- 1. Positive semidefinite forms
- 2. The projection theorem and the Riesz–Fréchet theorem
- 3. Sesquilinear forms and adjoints
- 8. Hilbert tensor products
- Adjoining an identity
- A C\*-norm on the unitization
- The resolvent; the spectrum is compact
- 4. Homomorphisms: contractivity, isometry and automatic continuity
- 8. The positive cone and the order
- 11. Approximate identities
- 15. Closed ideals and quotients
- 3. The Banach–Alaoglu theorem
- 6. The Krein–Milman theorem
- 15. Closed ideals and quotients
- Q25-GNS-ESSENTIAL: Arbitrary Hilbert spaces; zero and nondegenerate summands; arbitrary bounded approximate-identity nets
- Q25-GNS-NULL-SPACE: Nonunital star algebras and arbitrary positive functionals; no boundedness presumed
- Q25-GNS-COMPRESSED-BOUND: C* compressed functional estimate and bounded quotient multiplication only; broader old Banach-star theorem explicitly outside this replacement
- Q25-GNS-STATE-BOUNDS: Arbitrary nonunital C* algebra, arbitrary positive functional and positive contractive approximate-identity net
- Q25-GNS-CYCLIC: Arbitrary nonunital C* algebra and bounded state; cyclic unit vector; nondegenerate Hilbert representation
- Q25-GNS-FAITHFUL: Arbitrary nonunital C* algebra; faithful direct sum of cyclic nondegenerate representations
Locally compact cutoff functions
The Stone–Weierstrass theorem for functions vanishing at infinity: Proposition 2.1(3) and Corollary 5.2, for density and compact-set cutoff functions.
Inner actions and fixed algebras
- Scalar continuity implies norm continuity for Banach representations
- Compact spectral images and central fixed implementers
- Read the scalar phase, normalize, and obtain the exact kernel
- Discrete Fourier columns, finite corners and orbit MASAs
- Finite free actions and cocycle stability
- Internal Hilbert spaces in a von Neumann algebra
- Operator spaces and endomorphisms from internal Hilbert spaces
- Internal representations and irreducible multipliers
- Compact Tannaka reconstruction and centralizer rigidity
- Recognizing faithful dual weights
- Inner derivations in an arbitrary von Neumann algebra
- Bounded perturbations and differentiability domains of real actions
- Recognizing dual-invariant normal weights, including their infinite part
- Compact coefficient integration for normal covariant representations
- The Weyl-plane action and its continuous part
- Principal logarithms and small automorphisms
- Pointwise inner flows and continuous implementers
- Positive implementation from spectral tails
- Multiplier innerness, von Neumann uniformity, analytic measures, and positive energy
Induced actions and central quotients
- Pulling a central quotient back to the group
- Recognizing induced actions from a central quotient
- Stabilization of a normal induced crossed product
- Open subgroups and the regular corner
- Induction and crossed products for discrete groups
- Compact averaging identifies the subgroup fixed algebra
- Stabilization through compact averaging
- A continuous spectrum for an integrable abelian action
- Conditional probabilities in the Haar class of each orbit
- A proper topology for an integrable orbit model
- Bounded orbit sums need not be continuous
- Crossed products over varying compact stabilizers
- Conditional measures for arbitrary Borel maps
- Decomposing an action over its fixed centre
- Conditional measures as ergodic components
- Standard forms over a moving central base
- Measurable standard forms and canonical transport between varying fibres
- Invariant states over an abelian commutant
- Covariant representations over a moving diagonal
- A suspension from separated crossings
- Cohomology reduction for measurable flows
- Spectral normalizers and irrational rotation factors
- Integrability makes an ergodic abelian action homogeneous
Recognizing dual systems
Tensor weights and double-dual normalization
Supported weights and normalization
Trace scaling and continuous spectral coordinates
Core traces and changes of weight
- The core trace and its changes of weight
- Recovering a continuous core with its specified trace
- Continuous decompositions of arbitrary type III algebras
- Supported weights and their coordinates in the continuous core
- Graded fibers and changing weight coordinates
- Integrating graded sections
- Hilbert fibers and the represented core
- Countable orbit algebras and their modular weight
- Lifted orbit relations and the normalized core
- Modular spectra, periods and almost-periodic states
- Canonical core automorphisms and their continuity
- Relative commutants and central cocycles
- Dominant weights and inner comparison
- Trace-scaling cocycles and fixed corners
- Automorphisms and the outer exact sequence
- Pointwise absorption and dominant weights
- The global carrier and integrable weights
- Translation cocycles and the semifinite core
- Integrable weights and type-I densities
- From the global carrier to the fixed-trace density
- Finite carrier projections and their normal center measures
- Discrete decomposition and periodic weights
- Periodic weights and the scaling modulus
- Tensor products and the normalized flow of weights
- From a central cocycle to a full return algebra
- Type III zero factors from a contracting return automorphism
- Entropy at return times
- Changing the return section without changing the crossed product
- Recovering a discrete system from a modular spectral gap
- The same hyperfinite factor from different return systems
- Norm smoothing of measurable scalar cocycles
- Krieger's tower and its stopping invariant
- Tensor periods, modular subtypes and absorption
- Central perturbations, spectral gaps, and ambient maximal abelian algebras
- Spectral fibers and the full carrier of type I weights
- Normalized weights in a discrete coefficient algebra
- A fundamental band for the global weight carrier
- States with abelian centralizers and mutual commutants
- Comparing weights through strips and spectral tails
- Uniform distance and limits of weights
- Commuting approximations and finite domains of weights
- Trace tails and the smallest common majorant
- Spectral distributions and closed unitary orbits in semifinite factors
- A finite spectral cut of a core density
- Finite orbit blocks and type II∞ approximations of a type III₀ factor
- Assemble trace tails over the center
- Compatible expectations carry the core-center invariant to a limit
- From a compact spectral profile to the continuous core
- The central functional classifies closed unitary orbits
- Trace cutoffs, transport and homogeneous domains
- Finite densities and the graded integral
- Products, analytic powers and exact dual partners
- Spectral coordinates, localizers and finite mass
- A cocycle section needs a genuine joint coordinate
- Exact changes of weight and the limit of spectral continuity
- Normalizer defects and the characteristic square
- Periodic cores and the lifting obstruction
- Coordinates for equivariant central extensions
- When measurable coordinates recover a topology
- Compatible lifts and the phase of an outer period
- Twisted regular products and prescribed inner kernels
- Nontracial Bernoulli shifts on the original group of sites
- Amenable regular products and prescribed inner kernels
- An irrational characteristic class with no AFD realization
- Regular intertwiners and integrable cocycles