The orbit commutant proof route

The covariant commutant formula applies to arbitrary Hilbert spaces and locally compact Hausdorff groups. Its proof combines the coefficient Hilbert algebra and its closed polar decomposition with representation amplification and a normal slice. A nonfaithful representation uses its invariant central-kernel quotient.

The sections below give the orbit lesson’s mathematical prerequisites, their exact hypotheses and the order in which they are used.

Orbit representations and orthogonal state measures · Machine-readable proof route · Component authorship and terms

GNS

n_phi is a left ideal; finite linear extension on m_phi; dense-range GNS with Lambda(xa)=pi(x)Lambda(a); pi normal, unital, faithful; finite positive contractions e_i in n_phi intersect n_phi-star increase strongly to 1.

phi normal faithful semifinite on unital M, where semifinite means ultraweak density of m_phi. Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction.

WG: OA-MOD-WG-003. Domain algebra and its positive cone

WG: OA-MOD-WG-004. Linear extension without infinite subtraction

WG: OA-MOD-WG-005. Cauchy-Schwarz and the null ideal

WG: OA-MOD-WG-006. The GNS construction for an arbitrary weight

WG: OA-MOD-WG-007. Normality is a net argument

WG: OA-MOD-WG-008. Finite positive cutoffs characterize semifiniteness

WG: OA-MOD-WG-009. Density of the two-sided finite domain in the GNS space

WG: OA-MOD-WG-010. Faithfulness and the finite-weight specialization

Earlier steps: GNS.BASIC, GNS.NORMAL, BOUND.BK, BOUND.CP, HILBERT.BASIC.

ACTION

The given strongly continuous faithful covariant implementation implies norm continuity of every predual orbit and bounded joint sigma-strong-star continuity of (s,x) -> alpha_s(x).

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Given normal unital covariant rho,V with V strongly continuous; use the invariant central-kernel quotient if rho is nonfaithful.

SUPPORT: ORBIT-BRIDGE-COVARIANT-TOPOLOGY — The given implementation supplies action continuity

F11: OA-FLOW.TOP.JOINT — Simultaneously varying the automorphism and the element

WAcurrent: 12. Normal representations

Earlier steps: BOUND.CP.

REGULAR

pi_alpha is a faithful normal unital coefficient representation on H tensor L2(G); left translations are strongly continuous unitaries; covariance holds.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Coefficient representation faithful normal unital on arbitrary H.

F15: OA-FLOW.REG.CONSTRUCTION — Bounded coefficient operators and left translations

F15: OA-FLOW.REG.NORMALITY — Compact monotonicity handles arbitrary nets

Earlier steps: ACTION, HAAR.SECTIONS, BOUND.BK, BOUND.CP.

CONVOLUTION

K_alpha is an involutive algebra with right-coefficient convolution and Delta-dependent sharp; F_alpha has norm <= L1 norm and respects product, adjoint and coefficient module identities; kernel action is continuous compact-support and F_alpha is injective.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. K_alpha consists of compact-support strong-star continuous, norm-bounded coefficients.

F08: OA-FLOW.INT.OPERATIONS — The right-coefficient convolution

F08: OA-FLOW.INT.COVARIANT — Integrated operators and their identities

F08: OA-FLOW.INT.KERNEL — The regular action on vector sections

F08: OA-FLOW.INT.ALGEBRA — Algebra laws without formal rearrangements

Earlier steps: ACTION, REGULAR, HAAR.PRODUCT, HAAR.BASIC, BOUND.BK, BOUND.CP.

INTEGRATED.GENERATION

F_alpha(K_alpha) generates P; normalized shrinking compact-support scalar averages converge strongly to identity, recover every coefficient and every left group unitary.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Unital covariant pair, strongly continuous implementing representation.

F08: OA-FLOW.INT.GENERATION — Recovering both parts of covariance

Earlier steps: CONVOLUTION, HAAR.BASIC, BOUND.BK.

COEFFICIENT.DOMAIN

b_phi=span(K_alpha*n_phi on the right) is a left convolution ideal; tildeLambda(b_phi) consists of continuous compact-support sections and tildeLambda is injective.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. General nsf phi and the exact GNS identities; right M-module stability is not claimed.

F09: OA-FLOW.DW.GNSDOMAIN — An algebraic domain with a continuous GNS image

Earlier steps: GNS, CONVOLUTION, HAAR.SECTIONS.

COEFFICIENT.LEFT

tildeLambda(f*g)=F_alpha(f)tildeLambda(g) and tildeLambda(x dot g)=pi_alpha(x)tildeLambda(g).

f in K_alpha, g in b_phi, x in M; Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity.

F09: OA-FLOW.DW.GNSCONVOLUTION — Convolution becomes bounded left multiplication

Earlier steps: COEFFICIENT.DOMAIN, CONVOLUTION, GNS.

COEFFICIENT.STAR

B_phi=b_phi intersect b_phi-sharp is a star algebra containing b-star dot f dot a for finite-domain a,b.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. a,b in n_phi; no right ideal assertion for n_phi.

F09: OA-FLOW.DW.COMMON — A domain on which the involution is defined twice

Earlier steps: COEFFICIENT.DOMAIN, CONVOLUTION.

COEFFICIENT.DENSITY

A_phi=tildeLambda(B_phi) is Hilbert dense; F_alpha(B_phi) has strong closure P; products A_phi*A_phi are Hilbert dense.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. General nsf phi; directed finite positive contraction net from GNS, not a countable approximate unit.

F09: OA-FLOW.DW.DENSITY — Vector density, operator generation and products

Earlier steps: GNS, REGULAR, COEFFICIENT.LEFT, COEFFICIENT.STAR, INTEGRATED.GENERATION, HAAR.SECTIONS.

STANDARD.GNS

All nsf weights have canonical GNS maps in one weight-constructed standard form; common conjugation J; SF44 supplies U_alpha-star Lambda_phi(alpha(x))=Lambda_(phi circ alpha)(x).

Weights nsf; arbitrary algebra and Hilbert dimension. Automorphism is normal; strong continuity uses ACTION plus SF12 topology.

SF: OA-MOD-SF-08 — A finite matrix weight and its four closed graphs

SF: OA-MOD-SF-09 — Canonical comparison of the positive cones

SF: OA-MOD-SF-12 — Canonical implementation of automorphisms

SF: OA-MOD-SF-13 — One Hilbert space for all n.s.f. GNS maps

Earlier steps: GNS, WH.CORRESPONDENCE, MF.COMMUTANT, CONE.GEOMETRY, ACTION.

RELATIVE.TOMITA

S_(psi,phi)=J Delta_(psi,phi)^(1/2) closed with positive injective self-adjoint Delta; mixed domain x in n_phi intersect n_psi-star maps Lambda_phi(x) to Lambda_psi(x-star), and that mixed-domain graph is a core.

phi,psi nsf, canonical common standard realization. Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction.

SF: OA-MOD-SF-08 — A finite matrix weight and its four closed graphs

SF: OA-MOD-SF-09 — Canonical comparison of the positive cones

SF: OA-MOD-SF-13 — One Hilbert space for all n.s.f. GNS maps

F09: OA-FLOW.DW.IMPORT.TOMITA — Relative operators used for closability

Earlier steps: STANDARD.GNS, WH.CORRESPONDENCE, MF.COMMUTANT.

COEFFICIENT.CLOSURE

Jcal xi(s)=Delta_G(s)^(-1/2) U_s-star J xi(s-inverse) is an antiunitary involution; maximal pointwise T with fibers Delta_G(s)^(1/2) Delta_(phi circ alpha_s,phi)^(1/2) is closed; S0 subset Jcal T.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Relative Tomita domain and standard transport identities; each individual section is strongly measurable.

F09: OA-FLOW.DW.CLOSED-FIELDS — A pointwise closedness lemma

F09: OA-FLOW.DW.RELATIVETOMITA — Closing the coefficient involution

Earlier steps: RELATIVE.TOMITA, STANDARD.GNS, COEFFICIENT.DENSITY, HAAR.BASIC.

LEFT.HILBERT

A_phi with coefficient product and sharp is a left Hilbert algebra, with left von Neumann algebra exactly P.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. The four axioms are bounded left multiplication, adjoint identity, closable involution and dense products.

F09: OA-FLOW.DW.LEFTHILBERT — What the domain construction now provides

Earlier steps: COEFFICIENT.CLOSURE, COEFFICIENT.LEFT, COEFFICIENT.STAR, COEFFICIENT.DENSITY.

WH.CORRESPONDENCE

General nsf phi has a full finite-star Hilbert algebra with exact closed involution; its left-bounded vectors are precisely Lambda(n_phi), and the associated weight recovers phi on all positives, including infinite values.

phi nsf on arbitrary M; no faithful-state restriction.

WH: OA-MOD-WH-09 — From a faithful normal semifinite weight to an algebra

WH: OA-MOD-WH-10 — Closability on the full finite-star domain

WH: OA-MOD-WH-11 — Fullness and recovery of the original weight

Earlier steps: GNS, MF.KERNELS, NORMAL.WEIGHT.SUP, DOMINATED.WEIGHT.VECTORS, BOUND.BK, BOUND.CP.

MODULAR.ORIGINAL

sigma_t^phi is the conjugation action of Delta_phi^(it); it preserves phi and n_phi and obeys Lambda_phi(sigma_t(a))=Delta_phi^(it)Lambda_phi(a).

phi nsf; full weight Hilbert algebra; Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction.

MF: OA-MOD-MF-06 — The modular fundamental theorem

WH: OA-MOD-WH-11 — Fullness and recovery of the original weight

Earlier steps: MF.COMMUTANT, WH.CORRESPONDENCE, SPECTRAL.CALCULUS, BOUND.CP.

RELATIVE.IMAGINARY

Delta_(psi,phi)^(it)=[Dpsi:Dphi]_t Delta_phi^(it), with the same positive operator as RELATIVE.TOMITA.

phi,psi nsf in the common phi-standard form; balanced-matrix cocycle definition, not merely an unspecified modular cocycle.

SI: OA-MOD-SI-12. Ordinary relative GNS maps are a specialization

SI: OA-MOD-SI-14. The balanced-matrix cocycle is independent of the reference

SF: OA-MOD-SF-13 — One Hilbert space for all n.s.f. GNS maps

Earlier steps: RELATIVE.TOMITA, SPATIAL.IDENTIFICATION, MODULAR.ORIGINAL.

COCYCLE.CALCULUS

Balanced-matrix derivatives are unitary strongly-star continuous families; time cocycle, ordered chain rule, modular implementation and normal-automorphism pullback naturality hold.

All weights nsf on one arbitrary von Neumann algebra; normal automorphism or normal isomorphism for transport.

SI: OA-MOD-SI-14. The balanced-matrix cocycle is independent of the reference

CH: The ordered chain rule

CH: Reversal and paths of reference changes

F10: OA-FLOW.AWC.LAWS — Two parameters, two cocycle identities

Earlier steps: SPATIAL.IDENTIFICATION, MODULAR.ORIGINAL, SPECTRAL.CALCULUS.

TENSOR.WEIGHT

phi tensor mu is nsf, canonical on prescribed faithful spatial representation, with closed tensor Tomita operator and product modular group; automorphism pullback respects the specified tensor construction on all positive elements.

Both weights nsf; Hilbert factors arbitrary; no equality-of-weights inference solely from elementary positive tensor values.

TG: OA-MOD-TG-03 — Comparing spatial representations

TG: OA-MOD-TG-04 — Tensor Hilbert algebras and Tomita domains

TG: OA-MOD-TG-05 — All positive values and nonfaithful support corners

F10: OA-FLOW.AWC.IMPORT.WEIGHTS — Weight calculus, owned by OA-MOD

Earlier steps: WH.CORRESPONDENCE, CONE.GEOMETRY, MODULAR.ORIGINAL, SPECTRAL.CALCULUS, BOUND.CP, TENSOR.NATURALITY.

TENSOR.CONSTRUCTION

The specified tensor nsf weight has exact tensor GNS and closed Tomita polar decomposition, and its modular group is the product group.

Both weights nsf; arbitrary Hilbert dimensions; no naturality assertion included in this construction-only row.

TG: OA-MOD-TG-01 — Positive tensors and a graph core

TG: OA-MOD-TG-02 — Closed tensors, adjoints, and polar supports

TG: OA-MOD-TG-03 — Comparing spatial representations

TG: OA-MOD-TG-04 — Tensor Hilbert algebras and Tomita domains

TG: OA-MOD-TG-05 — All positive values and nonfaithful support corners

Earlier steps: WH.CORRESPONDENCE, CONE.GEOMETRY, MODULAR.ORIGINAL, SPECTRAL.CALCULUS, BOUND.CP, TENSOR.DOMAIN.

JOINT.COCYCLE

(s,t) -> [D(phi circ alpha_s):Dphi]_t is jointly sigma-strong-star continuous; pullback group/time/inverse laws M5 hold with the indicated factor order.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. General nsf phi, not assumed invariant.

F10: OA-FLOW.AWC.UNTWIST — Constructing a unitary without a field decomposition

F10: OA-FLOW.AWC.INVARIANT — An auxiliary invariant weight

F10: OA-FLOW.AWC.IDENTITY — Expressing every derivative using one curve

F10: OA-FLOW.DW.COCYCLECONT — Joint continuity at full group generality

F10: OA-FLOW.AWC.LAWS — Two parameters, two cocycle identities

Earlier steps: ACTION, STANDARD.GNS, COCYCLE.CALCULUS, TENSOR.WEIGHT, TENSOR.COCYCLE, HAAR.MULTIPLICATION, TENSOR.COMMUTANT.

COEFFICIENT.FLOW

R_t f(s)=Delta_G(s)^(it)c_t(s)sigma_t(f(s)) is a star-automorphism group of K_alpha, preserves supports/L1 norm and b_phi/B_phi.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Exact M3-M5 and JOINT.COCYCLE; bounded coefficient products.

F12: OA-FLOW.DW.COEFFICIENTFLOW — The modular-time action on coefficients

Earlier steps: JOINT.COCYCLE, MODULAR.ORIGINAL, COCYCLE.CALCULUS, CONVOLUTION.

MODULAR.UNITARY

Q_t xi(s)=Delta_G(s)^(it)Delta_(phi circ alpha_s,phi)^(it)xi(s) defines a strongly continuous unitary group and a unique positive nonsingular tildeDelta.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Exact relative imaginary-power identity and joint continuity; continuous compact-support vector density.

F12: OA-FLOW.DW.MODULARUNITARIES — Constructing a unitary group on the section space

Earlier steps: RELATIVE.IMAGINARY, JOINT.COCYCLE, HAAR.SECTIONS, STONE, SPECTRAL.CALCULUS.

SMOOTH.CALCULUS

For every smooth compact-support k, k(log tildeDelta) acts pointwise by k(log(Delta_G(s)Delta_relative(s))).

Self-adjoint global and pointwise generators from MODULAR.UNITARY; each target vector arbitrary, no universal exceptional set.

F12: OA-FLOW.DMO.FUNCTIONALCALCULUS — Smooth bounded functions act pointwise

Earlier steps: MODULAR.UNITARY, FOURIER.SMOOTH, HAAR.PRODUCT, SPECTRAL.CALCULUS.

REAL.POWERS

For each real r, D(tildeDelta^r) is exactly the maximal L2 pointwise domain with fiber Delta_G(s)^r Delta_relative(s)^r; action and squared-norm integral equal the fiber formula.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Fixed r and vector, arbitrary Hilbert dimension; negative powers have actual unbounded domains.

F12: OA-FLOW.DW.REALPOWERDOMAINS — Every real exponent, with its full domain

Earlier steps: SMOOTH.CALCULUS, SPECTRAL.CALCULUS.

IMAGINARY.INVARIANCE

tildeDelta^(it) tildeLambda(f)=tildeLambda(R_t f), hence tildeDelta^(it) A_phi=A_phi.

f in b_phi, exact general finite-domain GNS identity M3 and relative imaginary powers M4.

F12: OA-FLOW.DMO.INTERTWINING — Modular time preserves the common domain

Earlier steps: COEFFICIENT.FLOW, MODULAR.UNITARY, MODULAR.ORIGINAL, GNS.

GRAPH.CORE

Any dense linear D subset D(f(P)) invariant under every e^(itP) is a graph core for f(P), for Borel f finite spectral-a.e.; in particular for positive nonsingular A and every real A^r.

Arbitrary H; no D subset D(P) or countability assumption; actual domain inclusion is required.

F07: OA-FLOW.GRAPH.MAIN — The graph-localization theorem

F07: OA-FLOW.GRAPH.POWERS — Imaginary-power invariance controls real powers

Earlier steps: SPECTRAL.CALCULUS, SPECTRAL.REDUCTION.

CLOSED.POLAR

A_phi is a graph core for tildeDelta^(1/2); closure S0=Jcal tildeDelta^(1/2), which is its polar decomposition.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Exact half-power inclusion from D28 and REAL.POWERS; dense A_phi and IMAGINARY.INVARIANCE.

F12: OA-FLOW.DW.INVARIANTCORE — The closed involution and its polar decomposition

Earlier steps: COEFFICIENT.CLOSURE, COEFFICIENT.DENSITY, REAL.POWERS, IMAGINARY.INVARIANCE, GRAPH.CORE, SPECTRAL.CALCULUS.

MF.KERNELS

General Hilbert-algebra multiplication domains, affiliation, right-algebra density/commutant generation/product cores and WH03-04 full completion preserve the original closed involution and left algebra.

Arbitrary left Hilbert algebra (including nonunital/zero/nonseparable cases).

Building the two multiplication actions of a Hilbert algebra

Recovering the commutant from right-bounded vectors

WH: OA-MOD-WH-03 — Completing the two multiplication domains

WH: OA-MOD-WH-04 — Mixed bounded vectors and fullness

Earlier steps: BOUND.BK, HILBERT.BASIC, POLAR.CLOSED, SPECTRAL.CALCULUS.

MF.COMMUTANT

For any left Hilbert algebra with closed involution S=J Delta^(1/2), the generated left algebra satisfies JMJ=M-prime.

Arbitrary left Hilbert algebra; exact full completion and common graph domain for both half powers.

MF: OA-MOD-MF-01 — Starting data, full completion and exact inputs

MF: OA-MOD-MF-02 — The resolvent creates bounded multiplication

MF: OA-MOD-MF-03 — A common domain for the two half powers

MF: OA-MOD-MF-04 — The resolvent satisfies a weak operator equation

MF: OA-MOD-MF-05 — Fourier uniqueness recovers the commutant

MA: OA-MOD-MA-04 — Fourier uniqueness from Gaussian approximation

MA: OA-MOD-MA-06 — A spectral resolvent as a strong integral

MA: OA-MOD-MA-07 — Solving an equation expressed through unbounded pairings

Earlier steps: MF.KERNELS, POLAR.CLOSED, SPECTRAL.CALCULUS, SCALAR.ANALYSIS, BOUND.BK, HILBERT.BASIC.

BF75.I2

Jcal P Jcal=P-prime for the regular crossed product at full group/Hilbert-space generality.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Actual coefficient left Hilbert algebra LEFT.HILBERT and its exact CLOSED.POLAR identification.

The standard crossed-product commutant

Earlier steps: LEFT.HILBERT, CLOSED.POLAR, MF.COMMUTANT, STANDARD.GNS.EQUIVALENCE.

BF75.I5

P-prime=(M-prime tensor 1 union {U_g tensor R_g}) double-prime, with R_g xi(s)=Delta_G(g)^(1/2)xi(sg).

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Faithful standard realization, canonical strongly continuous U commuting J.

The standard crossed-product commutant

Earlier steps: BF75.I2, STANDARD.GNS.

BF77.E9

For every normal unital covariant rho,V, P_rho-prime=(rho(M)-prime tensor 1 union {V_g tensor R_g}) double-prime.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. V strongly continuous; arbitrary faithful normal representation comparison, with invariant central kernel quotient for nonfaithful rho.

The regular commutant in every covariant representation

Positive observations can be implemented by vector sums

Earlier steps: BF75.I5, POSITIVE.VECTOR.SERIES, TENSOR.SLICES, BOUND.BK, BOUND.CP.

ORBIT.1.4

For faithful multiplication D=L-infinity(Y,mu), D-prime=D and discrete Haar factor 1 yield R-prime=(pi-prime(D) union {t_g}) double-prime, t_g xi(s)=v_g xi(sg).

Original consumer: compact metrizable support Y, quasi-invariant Borel probability, countable discrete free point action. General E9 is retained upstream.

OWNED-3: 1. The support and the implemented model

Earlier steps: BF77.E9, ORBIT.MEASURE.MULTIPLICATION.

STONE

Every strongly continuous unitary real-line group on arbitrary H has a unique self-adjoint Stone generator, with exact norm-difference-quotient domain.

Strongly continuous unitary representation of the real line; arbitrary H.

SG: OA-MOD-SG-04 — Stone's theorem with the derivative domain

Earlier steps: SCALAR.ANALYSIS, SPECTRAL.CALCULUS, HILBERT.BASIC.

FOURIER.SMOOTH

FLOW12 M6-M7 smooth compact-support scalar inversion, L1 transform, and strong spectral integral identity.

k in Cc-infinity(real line); arbitrary self-adjoint P.

SUPPORT: ORBIT-BRIDGE-FOURIER — Smooth compact-support Fourier inversion

Earlier steps: SCALAR.ANALYSIS, SPECTRAL.CALCULUS.

SPECTRAL.REDUCTION

A closed subspace reducing every e^(itP) reduces every Borel spectral projection of P.

P self-adjoint on arbitrary H; no separability assumption.

SUPPORT: ORBIT-BRIDGE-SPECTRAL-REDUCTION — The spectral projections follow the unitary group

SG: OA-MOD-SG-04 — Stone's theorem with the derivative domain

SKcurrent: OA-MOD-SK-08 — Transport, reduction, and membership in an algebra

Earlier steps: STONE, SPECTRAL.CALCULUS.

HAAR.BASIC

General LCH Haar existence/uniqueness, compact cutoffs, positive normalized shrinking averages, continuous Delta and the exact inversion/right-translation formulas.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity.

HRcurrent: HR-06. Haar existence from normalized finite covers

HRcurrent: HR-07. Haar uniqueness on arbitrary groups

HRcurrent: HR-08. Open sigma compact cosets and the outer regular convention

HRcurrent: HR-09. Complete locally determined Haar measure and finite-exponent classes

GRcurrent: 3. Translations, the modular function and inversion

Earlier steps: SCALAR.ANALYSIS, HILBERT.BASIC.

HAAR.SECTIONS

H tensor L2(G) identifies with strongly measurable L2(G,H), with dense continuous compact-support sections.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Completed locally determined Haar convention; arbitrary H.

HRcurrent: HR-03. Finite-set regularity, densities and $L^p$ approximation

HRcurrent: HR-09. Complete locally determined Haar measure and finite-exponent classes

GRcurrent: 4. Vector integrals and the Hilbert tensor identification

Earlier steps: HAAR.BASIC, SCALAR.ANALYSIS, HILBERT.BASIC.

HAAR.PRODUCT

Radon-product integration at full nonmetrizable LCH scope: compact continuous scalar/vector integrands, open/lower-semicontinuous nonnegative section formulae, and completed Borel integrable functions on sigma-finite carriers.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Radon product rather than an asserted equality of product Borel sigma algebras; section representatives of finite-exponent vectors have sigma-compact carriers.

HRcurrent: HR-05. The Radon product, without a product-Borel assumption

GRcurrent: 4. Vector integrals and the Hilbert tensor identification

Earlier steps: HAAR.BASIC, HAAR.SECTIONS, SCALAR.ANALYSIS.

HAAR.MULTIPLICATION

Locally determined Haar L-infinity is a faithful normal multiplication MASA generated by Cc(G); integration is nsf, its standard conjugation is complex conjugation and its modular operator is 1.

Arbitrary locally compact Hausdorff G, left Haar measure, point-ultraweak action; no second countability, sigma compactness or unimodularity. Use local L-infinity, not a false identification with global outer-regular L-infinity.

SUPPORT: ORBIT-BRIDGE-HAAR-MASA — The local Haar multiplication algebra and its standard form

HRcurrent: HR-03. Finite-set regularity, densities and $L^p$ approximation

HRcurrent: HR-08. Open sigma compact cosets and the outer regular convention

HRcurrent: HR-09. Complete locally determined Haar measure and finite-exponent classes

Earlier steps: HAAR.SECTIONS, BOUND.BK, BOUND.CP, SCALAR.ANALYSIS.

TENSOR.COMMUTANT

(M-prime spatial-tensor Haar-D)-prime=M spatial-tensor Haar-D in the actual arbitrary weight-standard H tensor L2(G).

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. M arbitrary concrete, Haar D a multiplication MASA; no standard-form or weight premise.

SPATIALcurrent: **Theorem 11.4** (commutation theorem). For von Neumann algebras \(M\subseteq B(H)\) and \(N\subseteq B(K)\),

Tensor commutants and arbitrary representation amplification

SUPPORT: ORBIT-BRIDGE-HAAR-MASA — The local Haar multiplication algebra and its standard form

Earlier steps: SPATIAL.COMMUTATION, HAAR.MULTIPLICATION.

TENSOR.SLICES

Arbitrary-cardinal amplification commutant and normal rank-one slice membership used by BF77 E8-E9.

Arbitrary Hilbert L,K and concrete von Neumann algebra A.

SPATIALcurrent: **Theorem 5.2.**

SPATIALcurrent: **Proposition 7.1.** For a von Neumann algebra \(M\subseteq B(H)\) and any Hilbert space \(K\),

SPATIALcurrent: **Proposition 8.1.**

SPATIALcurrent: **Lemma 9.1.** For \(X\in M\bar\otimes N\) and all vectors, \(S_{\xi'}^*XS_\xi\in N\) and \(R_{\eta'}^*XR_\eta\in M\).

SPATIALcurrent: **Theorem 9.2** (slice maps). Let \(X\in M\bar\otimes N\).

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, SPATIAL.GENERATORS, SPATIAL.AMPLIFICATION, SPATIAL.FLIP, SPATIAL.SLICES.

POSITIVE.VECTOR.SERIES

Every normal positive functional on a concrete unital arbitrary-H von Neumann algebra is a positive vector series with summable squared norms.

Normal positive functional; normal image/inverse when transferring between faithful representations. No separability assumption.

BIcurrent: 10. Positive normal functionals as sums of vector functionals

WAcurrent: 12. Normal representations

Positive observations can be implemented by vector sums

Earlier steps: BOUND.BK, BOUND.CP, HILBERT.BASIC.

POLAR.CLOSED

General closed antilinear involution S has exact-domain polar S=J Delta-half, F=J Delta-minus-half, Delta=FS, SF=Delta-inverse, and J Delta^z J=Delta^(-conjugate(z)). Ordinary linear closed graphs/adjoints and T-star-T half-power form domain are included.

Arbitrary closed densely defined operators and left Hilbert algebras; no vector-model, state or separability premise.

Exact domain instantiation for the preserved commutant proof

Closing an involution and recovering its modular data

Recovering operators from energy forms

Earlier steps: BOUND.BK, HILBERT.BASIC, SPECTRAL.CALCULUS.

SPECTRAL.CALCULUS

Arbitrary-H Borel spectral calculus with actual power/log domains, transport, affiliation, and a common graph approximation for both positive and negative half powers.

General self-adjoint operators; common graph domain V=D(A-half) intersect D(A-minus-half), no countability reduction.

Exact domain instantiation for the preserved commutant proof

Spectral calculus with its domains retained

Earlier steps: BOUND.BK, HILBERT.BASIC, SCALAR.ANALYSIS.

TENSOR.DOMAIN

Existing TG1-2 instantiated: the closed positive tensor has its full spectral integral domain and rectangular graph cutoffs, including zero factors and cancellation domains.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Both factors positive self-adjoint; ordinary algebraic tensor is a graph core for the closed tensor.

The tensor-domain formulas and their graph core

Earlier steps: SPECTRAL.CALCULUS, HILBERT.BASIC.

TENSOR.NATURALITY

OT1: tensor nsf weights transport under the normal spatial tensor isomorphism on every positive element, including infinite values, via full Hilbert-algebra/GNS and multiplier-vector transport.

Both factor maps normal unital star isomorphisms; all factor weights nsf; arbitrary dimensions.

ROOTtensor: ORBIT-TENSOR-TRANSPORT — Naturality on the entire positive cone

The tensor-domain formulas and their graph core

Earlier steps: TENSOR.CONSTRUCTION, TENSOR.DOMAIN, WH.CORRESPONDENCE.

TENSOR.COCYCLE

OT2-3: the matrix/tensor diagonal weight agrees on all positives, and the same-second-factor balanced-matrix cocycle equals the first-factor cocycle tensor identity.

phi1,phi2 nsf on M and the same nsf mu on N; intrinsic SI64-66 cocycle convention; no countability assumption.

ROOTtensor: ORBIT-TENSOR-DIAGONAL — A diagonal tensor weight has the prescribed two corners

ROOTtensor: ORBIT-TENSOR-COCYCLE — Cancellation of the common second factor

The tensor-domain formulas and their graph core

Earlier steps: TENSOR.CONSTRUCTION, TENSOR.DOMAIN, COCYCLE.CALCULUS, WH.CORRESPONDENCE.

GNS.BASIC

The general finite left ideal and linear finite extension give a dense GNS space and bounded left representation, before its normality conclusion.

phi normal weight; semifiniteness/faithfulness only where WG explicitly requires them. Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction.

WG: OA-MOD-WG-003. Domain algebra and its positive cone

WG: OA-MOD-WG-004. Linear extension without infinite subtraction

WG: OA-MOD-WG-005. Cauchy-Schwarz and the null ideal

WG: OA-MOD-WG-006. The GNS construction for an arbitrary weight

Earlier steps: BOUND.BK, BOUND.CP, HILBERT.BASIC.

NW.CONVEX

Exact arbitrary locally convex separation, Banach-Alaoglu/Hilbert weak-ball compactness and Krein-Smulian bounded-slice criterion used by NW06-10.

General Banach dual M=(M_*)-star and real selfadjoint convex sets; no separability assumption.

Predual, normal-weight and cone arguments for the orbit proof

Earlier steps: BOUND.CP, HILBERT.BASIC, BOUND.BK.

NORMAL.WEIGHT.SUP

Every normal weight is the supremum on all positives of its dominated bounded normal positive functionals, including zero and infinite values.

Arbitrary normal weights on arbitrary M; dominated family need not be directed.

Detecting normal weights by finite observations

Predual, normal-weight and cone arguments for the orbit proof

Earlier steps: GNS.BASIC, NW.CONVEX, BOUND.CP.

GNS.NORMAL

WG007 increasing-net strong convergence and NW11 give normality of every GNS vector pullback by positive-functional norm closure, and hence normality of the GNS representation.

phi arbitrary normal weight, before any semifiniteness restriction.

WG: OA-MOD-WG-007. Normality is a net argument

Predual, normal-weight and cone arguments for the orbit proof

Earlier steps: GNS.BASIC, NORMAL.WEIGHT.SUP, BOUND.CP.

DOMINATED.WEIGHT.VECTORS

OW02-03 give a bounded positive commutant contraction and exact implementing vector for omega<=phi; the general finite contraction net supplies all-positive order and the polar target-range equality.

phi normal semifinite, including nonfaithfulness; omega bounded normal positive; finite domination constant. Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction.

OW: OA-MOD-OW-02. What a comparison operator remembers

OW: OA-MOD-OW-03. The vector implementing a finite observation

Predual, normal-weight and cone arguments for the orbit proof

Earlier steps: GNS, NORMAL.WEIGHT.SUP, BOUND.CP, POLAR.CLOSED.

STANDARD.GNS.EQUIVALENCE

Every prescribed axiomatic standard form is unitarily equivalent to the standard form of any nsf weight; the unitary preserves algebra, J and cone, and transports canonical automorphism implementations.

Arbitrary standard forms and normal unital star isomorphism; arbitrary cardinal directed support corners, no faithful state on the whole M.

SE: OA-MOD-SE-10 — Patching the unique comparisons

SE: OA-MOD-SE-11 — Transporting positive functionals and automorphisms

WH: OA-MOD-WH-13 — Every von Neumann algebra has such a weight

Predual, normal-weight and cone arguments for the orbit proof

Earlier steps: STANDARD.GNS, STANDARD.CORNER.PATCHING, CONE.GEOMETRY, GNS.

SPATIAL.MATRICES

Arbitrary basis columns, operator matrices, entrywise commutation and bounded finite-subset strong truncations.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Proposition 1.3.**

SPATIALcurrent: **Proposition 2.1.**

Tensor commutants and arbitrary representation amplification

Earlier steps: HILBERT.BASIC, BOUND.BK.

SPATIAL.GENERATORS

Normal amplification and extension, generated spatial tensor algebra, von Neumann amplification and matrix algebra.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Proposition 3.1.**

SPATIALcurrent: **Lemma 4.1** (amplified density). Let \(A\subseteq B(H)\) be a \(*\)-subalgebra with \(1\in A\), and let \(x\in A''\). For every sequence \((\xi_n)\) in \(H\) with \(\sum_n\|\xi_n\|^2<\infty\), finite families included, and every \(\varepsilon>0\), there is \(a\in A\) with

SPATIALcurrent: **Theorem 4.2** (bicommutant theorem). For a \(*\)-subalgebra \(A\subseteq B(H)\) with \(1\in A\), \(A''\) is the closure of \(A\) in the strong, the weak and the ultraweak topology. A \(*\)-subalgebra that contains \(1\) and is closed in one of these topologies is a von Neumann algebra.

SPATIALcurrent: **Proposition 4.3** (normal extension principle). Let \(M\) be a von Neumann algebra on \(H\), \(A\subseteq M\) a \(*\)-subalgebra with \(1\in A\) and \(A''=M\), and \(\Phi,\Psi:M\to B(L)\) normal linear maps.

SPATIALcurrent: **Theorem 5.2.**

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, BOUND.BK, BOUND.CP.

SPATIAL.AMPLIFICATION

(A tensor identity)-prime=A-prime spatial-tensor B(L), with finite-subset matrix proof.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Proposition 7.1.** For a von Neumann algebra \(M\subseteq B(H)\) and any Hilbert space \(K\),

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, SPATIAL.GENERATORS.

SPATIAL.FLIP

Associativity, flip, normal leg maps and spatial transport.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Proposition 8.1.**

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, SPATIAL.GENERATORS.

SPATIAL.SLICES

Normal vector slices belong to the opposite tensor leg; norm and module rules; arbitrary Hilbert dimensions.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Lemma 9.1.** For \(X\in M\bar\otimes N\) and all vectors, \(S_{\xi'}^*XS_\xi\in N\) and \(R_{\eta'}^*XR_\eta\in M\).

SPATIALcurrent: **Theorem 9.2** (slice maps). Let \(X\in M\bar\otimes N\).

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, BOUND.CP, SPATIAL.AMPLIFICATION.

SPATIAL.COMMUTATION

Full arbitrary-H commutation (M spatial-tensor N)-prime=M-prime spatial-tensor N-prime.

Arbitrary Hilbert dimension and predual; no faithful-state/countability reduction. Concrete von Neumann algebras; no modular or weight premise.

SPATIALcurrent: **Proposition 6.1.** Let \(M\) be a von Neumann algebra on \(H\).

SPATIALcurrent: **Lemma 11.1.** If \(a,b\in B(H)\) are commuting self-adjoint operators and \(\xi\in H\), then \(a\xi\perp ib\xi\) in the real sense. In particular \(M_h\xi\perp iM'_h\xi\) for a von Neumann algebra \(M\).

SPATIALcurrent: **Lemma 11.2.** Let \(M\) be a von Neumann algebra on \(H\) with a cyclic vector \(\xi_0\), that is, \([M\xi_0]=H\). Let \(A\subseteq M\) and \(B\subseteq M'\) be \(*\)-subalgebras.

SPATIALcurrent: **Lemma 11.3.** Let \(X\subseteq H\) and \(Y\subseteq K\) be real subspaces such that \(X+iX\) is dense in \(H\) and \(Y+iY\) is dense in \(K\). Let \(X\odot Y\) be the real span of the \(\xi\otimes\eta\) with \(\xi\in X\), \(\eta\in Y\). Then \(X\odot Y+i(X^\perp\odot Y^\perp)\) is dense in \(H\otimes K\).

SPATIALcurrent: **Theorem 11.4** (commutation theorem). For von Neumann algebras \(M\subseteq B(H)\) and \(N\subseteq B(K)\),

Tensor commutants and arbitrary representation amplification

Earlier steps: SPATIAL.MATRICES, SPATIAL.GENERATORS, SPATIAL.AMPLIFICATION, HILBERT.BASIC, BOUND.BK.

STANDARD.CORNER.PATCHING

SE01-09: full standard-cone support corners, relative closed graph-core recognition, directed finite joins and density of their corner union.

SE: OA-MOD-SE-01 — Axioms and the geometric facts available before comparison

SE: OA-MOD-SE-02 — Compression and the commutant

SE: OA-MOD-SE-03 — Every projection has a faithful cone corner

SE: OA-MOD-SE-04 — The two cyclic domains are graph cores

SE: OA-MOD-SE-05 — Recognizing a modular conjugation by its exact graph

SE: OA-MOD-SE-06 — The corner seen by a positive vector

SE: OA-MOD-SE-07 — Closing one order ideal gives its entire supported face

SE: OA-MOD-SE-08 — Projections and all closed cone faces

SE: OA-MOD-SE-09 — Finding a full-support vector on each small corner

CONE.GEOMETRY

Weight-constructed natural cone is self-dual, spans H, has pointwise J-fixedness, unique cone-preserving commutant unitary, and every bounded normal positive functional has a unique cone vector with square-root norm estimate.

The positive cone of a standard representation

Predual, normal-weight and cone arguments for the orbit proof

SPATIAL.IDENTIFICATION

For a general nsf numerator and nsf commutant denominator, the coefficient form is closed/dense and equals the complete rectangular linking-weight Tomita energy form; modular conjugation actions identify the relative ordinary two-weight graph with the spatial derivative.

SI: OA-MOD-SI-02. The opposite weight and its modular data

SI: OA-MOD-SI-03. Unitary and antiunitary changes of representation

SI: OA-MOD-SI-04. Every finite rectangular intertwiner has a vector

SI: OA-MOD-SI-05. A diagonal weight separates four graph corners

SI: OA-MOD-SI-06. The first GNS column is the original representation

SI: OA-MOD-SI-07. The relative map has exactly the coefficient form

SI: OA-MOD-SI-12. Ordinary relative GNS maps are a specialization

SI: OA-MOD-SI-14. The balanced-matrix cocycle is independent of the reference

Earlier steps: SPATIAL.DIRECTFORM.

BOUND.BK

Bounded bicommutant/commutant framework, positive square roots and support/inverse order, four-unitary span, bounded-net limits and von Neumann polar/Douglas facts.

BK01–08 and the established bounded operator foundations

BOUND.CP

Concrete arbitrary-H Banach preduals, summable vector-pair functionals, positive normal-map criterion, and normal functional decomposition.

CP06–12: arbitrary-H concrete preduals and bounded supports

HILBERT.BASIC

Arbitrary-H completion, orthogonal projection, adjoints and bounded sesquilinear-form representation.

Hilbert-space completion, projection and Riesz representation

SCALAR.ANALYSIS

Scalar Lebesgue finite-measure integration, monotone/dominated convergence, absolute Fubini, change of variables/integration by parts, Gaussian transform MA03, and scalar Cauchy/residue tools for MA06-07.

Modular analytic scalar integrals and their measure prerequisites

Scalar integration, monotone and dominated convergence, and Fubini

Complete integrable spaces

Scalar measure and spectral foundations

ORBIT.MEASURE.MULTIPLICATION

Original metric probability-space multiplication MASA, Radon-Nikodym transport, support/density and existing state-integral contracts.

The orbit lesson and its named earlier state-integral and measure proofs

SPATIAL.BOUNDEDVECTORS

Bounded vectors, coefficient ideal and finite-energy polarization

Exact hypotheses and complete proof domains in the linked programme section.

Which vectors define bounded intertwiners?

Earlier steps: GNS.BASIC, BOUND.BK, HILBERT.BASIC.

WEIGHT.SUPPORTS

Finite-domain, null and supported faithful semifinite weight corners

Exact hypotheses and complete proof domains in the linked programme section.

The projection of the finite domain

Earlier steps: GNS.BASIC, BOUND.BK.

FORMS.CORES

Canonical closure, exact form cores and resolvent order

Exact hypotheses and complete proof domains in the linked programme section.

The completion test and canonical closure

Earlier steps: HILBERT.BASIC, SPECTRAL.CALCULUS, FORMS.FACTORIZATION.

FORMS.FACTORIZATION

Bounded contraction factorization inside the algebra

Exact hypotheses and complete proof domains in the linked programme section.

A factorization inside the algebra

Earlier steps: BOUND.BK, HILBERT.BASIC.

SPATIAL.DIRECTFORM

Full direct spatial energy construction, closure, null space, exact domains and form order

Exact hypotheses and complete proof domains in the linked programme section.

Conventions and the actual prerequisites

Earlier steps: SPATIAL.BOUNDEDVECTORS, WEIGHT.SUPPORTS, FORMS.CORES, NORMAL.WEIGHT.SUP, BOUND.CP, SPECTRAL.CALCULUS.

Human source context

Masamichi Takesaki, Theory of Operator Algebras II, Definition X.1.3 and Theorem X.1.21 / Corollary X.1.22(i), printed pages 240 and 253–255; publisher edition. The quotient qualification under a literal nonfaithful reading is stated in the covariant proof; the concrete commutant identity and the abstract quotient crossed product are distinct assertions.

Kawamura, Takemoto and Tomiyama, State extensions in transformation group C*-algebras, Section 1, provides a freely accessible comparison. This edition proves its own represented-algebra norm bound, purity, orbit equivalence and orthogonal-measure statements.

Downstream spatial convergence

The convergence consequence SI15 requires the spatial convergence theorem SS09. The SC01–10 and SI08/SI14 arguments use the direct-form and modular results linked above.

Further prerequisite results

The following results retain their exact hypotheses and domains. The general BF15 argument retains its action-topology and weak compact convex hull inputs. CI06 states the scalar multiplier’s closed-strip continuity explicitly.

TT1-IV.8.Ex1

8. The direct integral Hilbert space

TT1-V.6.1

6. Closed subspaces of a Hilbert space

TT1-V.7.1

The largest identity part

TT1-V.7.2

The largest identity part

TT1-V.7.3

The ergodic dichotomy and effective quotient

TT1-V.7.4

Bounded coefficient operators and left translations

Compact monotonicity handles arbitrary nets

TT1-V.7.5

Ultraweak L^1 averages and matrix coefficients

Locating the regular algebra in one tensor product

The normal comparison and its generators

Relabeling the coefficient system

TT2-A.7

A form includes its domain

TT2-A.8

A form includes its domain

Representation with the exact square-root domain

Nondense forms, lower semicontinuity, and symmetry

The completion test and canonical closure

Closedness and lower semicontinuity on all vectors

Closability and lower semicontinuity on the given domain

Cores determine the domain, not just a dense set of vectors

TT2-A.9

Problems with solutions — Problem 5

When a form sum equals an operator sum

TT2-A.10

Resolvents as energy minimizers

One resolvent inequality recovers the whole form order

A factorization inside the algebra

TT2-A.11

The domain of an increasing limit

Strong convergence of resolvents, including nets

Logarithms and imaginary powers

Worked models

TT2-A.12

Compatible pairs, intersections, and sums

The bounded-strip estimate

The strip space is complete

Evaluation spaces and quotient completeness

Interpolating a bounded linear map

Checks and solved exercises

Further proofs on this route