Original text: CC0 1.0. Prerequisite proofs and component terms.

Spatial energy as a corner of a modular operator

OA-MOD-SI-01. Conventions and exact inputs

Let M⊆B(H)M\subseteq B(H) be a concrete unital von Neumann algebra, put N=M′N=M', and fix an NSF weight ψ\psi on NN. Here NSF means normal, semifinite and faithful. The Hilbert space and all indexing sets are arbitrary. Inner products are linear in the first variable.

Use SC-01–10 for the direct spatial form. Thus Rψ(ξ)Λψ(y)=yξ,θψ(ξ)=Rψ(ξ)Rψ(ξ)∗,ξ∈Dψ.(SI.1) R_\psi(\xi)\Lambda_\psi(y)=y\xi,\qquad \theta_\psi(\xi)=R_\psi(\xi)R_\psi(\xi)^*,\qquad \xi\in D_\psi. \tag{SI.1} For a normal numerator φ\varphi, its closed form has domain VφV_\varphi, Hilbert closure eφHe_\varphi H, and null space fφHf_\varphi H. Its effective support is pφ=eφ−fφp_\varphi=e_\varphi-f_\varphi. Its represented operator acts on eφHe_\varphi H; for a semifinite numerator, eφ=1e_\varphi=1.

The exact further inputs are WG's GNS and finite-ideal results; WS-02–06's finite and null corners; OW-03/08's opposite-weight vector criterion; WH-02–13's full Hilbert algebras, right weight, GNS identifications and existence of an NSF weight; and MF-05–06's modular conjugation and modular automorphism theorem. BK supplies bounded polar decompositions, bicommutants and operator topologies. TC supplies closed-involution polar decomposition. SK-05–09 supplies the spectral calculus with actual domains. FC and QF supply closed-form uniqueness and representation. SS-09 is used for the final convergence consequence. CP's normal vector-series representation supplies its predual-topology step. MA enters through MF's already proved analytic arguments; no additional strip theorem is assumed here.

These results use their stated scalar and Hilbert-space prerequisites. In particular, the argument does not invoke the uniqueness part of the KMS characterization to identify a corner modular group. It identifies that group's GNS operator directly.

For a closed antilinear map TT, write ∣T∣=(T∗T)1/2|T|=(T^*T)^{1/2}. The relative modular operator in this unit is ΔT=T∗T=∣T∣2.(SI.2) \Delta_T=T^*T=|T|^2. \tag{SI.2} This convention is fixed by the squared-norm energy formula. An antilinear polar factor between different Hilbert spaces is not automatically a conjugation on either space.

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

Let ω\omega be NSF on an algebra BB, and identify BB with its faithful GNS image on K=HωK=H_\omega. Write S,J,ΔS,J,\Delta for its modular data. Let ωopp\omega^{\mathrm{opp}} be the OW weight on B′B'.

Proposition. Its GNS space identifies canonically with KK, its closed involution is S∗S^*, and its modular data are J,Δ−1J,\Delta^{-1}. For positive b∈Bb\in B, ωopp(JbJ)=ω(b),(ωopp)opp=ω(SI.3) \omega^{\mathrm{opp}}(JbJ)=\omega(b),\qquad (\omega^{\mathrm{opp}})^{\mathrm{opp}}=\omega \tag{SI.3} under these specified GNS identifications. In particular, σtωopp(c)=Δ−itcΔit(c∈B′).(SI.4) \sigma_t^{\omega^{\mathrm{opp}}}(c)=\Delta^{-it}c\Delta^{it} \quad(c\in B'). \tag{SI.4}

Proof. Let A=Λω(nω∩nω∗)\mathcal A=\Lambda_\omega(\mathfrak n_\omega\cap\mathfrak n_\omega^*) be the full left algebra and D\mathcal D its full right algebra. WH identifies its right weight with ωopp\omega^{\mathrm{opp}}. If Rη∈B′R_\eta\in B' is the right multiplier of a right-bounded vector, the canonical GNS identification is Γ(Rη)=η,ωopp(Rη∗Rη)=∥η∥2.(SI.5) \Gamma(R_\eta)=\eta, \qquad \omega^{\mathrm{opp}}(R_\eta^*R_\eta)=\|\eta\|^2. \tag{SI.5} WH's finite-ideal theorem makes this the entire GNS map, not just a dense submap. Its finite-star algebra is Dop\mathcal D^{\mathrm{op}}, whose closed involution is F=S∗F=S^*. TC gives F=JΔ−1/2F=J\Delta^{-1/2}. Polar uniqueness gives the asserted modular data and MF gives (SI.4).

For completeness, MF's identity JλξJ=RJξJ\lambda_\xi J=R_{J\xi} also extends to all left-bounded vectors, and symmetrically to right-bounded vectors. Indeed, if η\eta is right bounded and ζ∈D\zeta\in\mathcal D, then RζJη=JλJζη=JRηJζ. R_\zeta J\eta=J\lambda_{J\zeta}\eta=JR_\eta J\zeta. This is exactly the left-bounded test for JηJ\eta, with multiplier JRηJJR_\eta J. The reverse follows by J2=1J^2=1.

Now ω(b)<∞\omega(b)<\infty precisely when b1/2=λξb^{1/2}=\lambda_\xi for a left-bounded vector ξ\xi, and its value is ∥ξ∥2\|\xi\|^2. The preceding identity makes Jb1/2J=RJξJb^{1/2}J=R_{J\xi}, with the same squared norm. The symmetric argument proves the converse. Thus the finite positive cones and their values correspond, proving the first formula of (SI.3), including infinite values. Applying WH's construction to the opposite right algebra recovers the original full left algebra and its weight. This proves the double-opposite assertion. ∎

We will also use the equality between Dω(K)D_\omega(K), defined by the GNS test, and the right-bounded space just used. Restriction of the GNS test gives one inclusion. For the other, choose finite positive contractions ui↑1u_i\uparrow1. If x∈nωx\in\mathfrak n_\omega, then uix∈nω∩nω∗u_i x\in\mathfrak n_\omega\cap\mathfrak n_\omega^*, Λ(uix)→Λ(x)\Lambda(u_i x)\to\Lambda(x), and uixη→xηu_i x\eta\to x\eta. The bounded right-multiplier identity on the finite-star algebra therefore extends to all x∈nωx\in\mathfrak n_\omega. This proves the equality with its exact operator.

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

Let C:H→H~C:H\to\widetilde H be unitary or antiunitary. Transport both algebras by x↦CxC−1x\mapsto CxC^{-1}, and transport each weight on positive elements by composition with the inverse map. The latter is well-defined even when the map is conjugate-linear: it preserves addition, nonnegative scalar multiplication, positivity and positive suprema.

Lemma. The transported spatial form has domain CVφCV_\varphi and energy q~[Cξ]=q[ξ].(SI.6) \widetilde q[C\xi]=q[\xi]. \tag{SI.6} Its operator, on the transported Hilbert subspace, is CAC−1CAC^{-1} with domain CD(A)CD(A).

Proof. The GNS map GΛψ(y)=Λψ~(CyC−1) G\Lambda_\psi(y)=\Lambda_{\widetilde\psi}(CyC^{-1}) extends to a unitary or antiunitary of the same type as CC. Its norm equality follows from the weight formula; polarization gives the appropriate inner-product identity. It has dense range because the entire finite left ideal is transported bijectively. The defining bounded-vector test then gives Dψ~=CDψ,Rψ~(Cξ)=CRψ(ξ)G−1.(SI.7) D_{\widetilde\psi}=CD_\psi, \qquad R_{\widetilde\psi}(C\xi)=CR_\psi(\xi)G^{-1}. \tag{SI.7} Both sides of the second formula are linear operators. Their coefficients are Cθψ(ξ)C−1C\theta_\psi(\xi)C^{-1}, so their initial energies agree. The same map preserves the form-completion norm. SC's canonical closure therefore gives (SI.6) on the full domains. Real spectral calculus and closed-form uniqueness identify the represented operator and its domain. ∎

For an antiunitary CC, complex powers require the scalar conjugation: CAitC−1=(CAC−1)−it.(SI.8) C A^{it}C^{-1}=(CAC^{-1})^{-it}. \tag{SI.8} This follows from SK's antiunitary Borel calculus; it is not the formula for a unitary change of representation.

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

Return to N⊆B(H)N\subseteq B(H), ψ\psi, and K=HψK=H_\psi. Put B=πψ(N)′,χ=ψopp,X={X∈B(K,H):Xπψ(y)=yX (y∈N)}.(SI.9) B=\pi_\psi(N)',\qquad \chi=\psi^{\mathrm{opp}}, \qquad \mathcal X=\{X\in B(K,H):X\pi_\psi(y)=yX\ (y\in N)\}. \tag{SI.9}

Theorem. The following maps are inverse bijections: Dψ⟶{X∈X:χ(X∗X)<∞},ξ⟼Rψ(ξ),{X∈X:χ(X∗X)<∞}⟶Dψ,X⟼η(X).(SI.10) \begin{aligned} D_\psi&\longrightarrow\{X\in\mathcal X:\chi(X^*X)<\infty\},\\ \xi&\longmapsto R_\psi(\xi),\\ \{X\in\mathcal X:\chi(X^*X)<\infty\}&\longrightarrow D_\psi,\\ X&\longmapsto\eta(X). \end{aligned} \tag{SI.10} They satisfy χ(X∗X)=∥η(X)∥2,η(aX)=aη(X)(a∈M).(SI.11) \chi(X^*X)=\|\eta(X)\|^2, \quad \eta(aX)=a\eta(X)\quad(a\in M). \tag{SI.11}

Proof. Use the rectangular polar decomposition X=VhX=Vh, where h=(X∗X)1/2∈Bh=(X^*X)^{1/2}\in B. The polar factor intertwines the two NN-actions. Its initial and final projections P=V∗V∈BP=V^*V\in B and Q=VV∗∈MQ=VV^*\in M are the respective support projections.

If χ(h2)<∞\chi(h^2)<\infty, OW-08 supplies a unique ζ∈K\zeta\in K such that hΛψ(y)=πψ(y)ζ,∥ζ∥2=χ(h2)(y∈nψ). h\Lambda_\psi(y)=\pi_\psi(y)\zeta, \qquad\|\zeta\|^2=\chi(h^2) \quad(y\in\mathfrak n_\psi). Because Ph=hPh=h and PP commutes with πψ(N)\pi_\psi(N), the vector (1−P)ζ(1-P)\zeta is annihilated by every πψ(y)\pi_\psi(y) in that finite ideal. Finite cutoffs imply Pζ=ζP\zeta=\zeta. Set η(X)=Vζ\eta(X)=V\zeta. Then XΛψ(y)=yVζ,∥Vζ∥=∥ζ∥, X\Lambda_\psi(y)=yV\zeta, \qquad\|V\zeta\|=\|\zeta\|, so X=Rψ(η(X))X=R_\psi(\eta(X)) and (SI.11)'s norm formula follows.

Conversely let X=Rψ(ξ)X=R_\psi(\xi). Since QX=XQX=X, the equation (1−Q)yξ=0(1-Q)y\xi=0 and finite cutoffs give Qξ=ξQ\xi=\xi. Hence ζ=V∗ξ\zeta=V^*\xi has norm ∥ξ∥\|\xi\|, and hΛψ(y)=V∗yξ=πψ(y)ζ. h\Lambda_\psi(y)=V^*y\xi=\pi_\psi(y)\zeta. OW-08 gives χ(X∗X)=∥ξ∥2\chi(X^*X)=\|\xi\|^2. Injectivity of RψR_\psi, proved in SD, makes the two constructions inverse. The covariance Rψ(aξ)=aRψ(ξ)R_\psi(a\xi)=aR_\psi(\xi) gives the final assertion. Linearity of the inverse follows from injectivity and linearity of RψR_\psi. ∎

The theorem proves surjectivity onto the whole finite rectangular ideal. Merely expressing some intertwiners as products would not supply the GNS identification needed next.

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

Here is the block argument in a general algebra. Let LL be a von Neumann algebra with complementary projections e,fe,f, and let α,β\alpha,\beta be NSF weights on eLe,fLfeLe,fLf. Define ρ(z)=α(eze)+β(fzf),z∈L+.(SI.12) \rho(z)=\alpha(eze)+\beta(fzf),\qquad z\in L_+. \tag{SI.12}

Lemma. This is NSF. On its GNS space HρH_\rho, left multiplication Li=πρ(i)L_i=\pi_\rho(i) and QiΛρ(x)=Λρ(xi),i=e,f,(SI.13) Q_i\Lambda_\rho(x)=\Lambda_\rho(xi),\qquad i=e,f, \tag{SI.13} are commuting orthogonal projections. Put Hij=LiQjHρH_{ij}=L_iQ_jH_\rho. The closed Tomita map SρS_\rho carries D(Sρ)∩HijD(S_\rho)\cap H_{ij} bijectively onto D(Sρ)∩HjiD(S_\rho)\cap H_{ji}, and SρLiQjξ=LjQiSρξ(ξ∈D(Sρ)).(SI.14) S_\rho L_iQ_j\xi=L_jQ_i S_\rho\xi \quad(\xi\in D(S_\rho)). \tag{SI.14} Each Li,QjL_i,Q_j reduces Δρ\Delta_\rho, and JρLiJρ=Qi,JρHij=Hji.(SI.15) J_\rho L_iJ_\rho=Q_i, \qquad J_\rho H_{ij}=H_{ji}. \tag{SI.15} The vectors Λρ(iLj∩nρ∩nρ∗)(SI.16) \Lambda_\rho(iLj\cap\mathfrak n_\rho\cap\mathfrak n_\rho^*) \tag{SI.16} form a graph core for the restricted Tomita map on HijH_{ij}.

Proof of the weight and projections. Compression is positive and normal; addition proves the weight axioms and normality. If z≥0z\geq0 has both diagonal compressions zero, then z1/2e=z1/2f=0z^{1/2}e=z^{1/2}f=0, so z=0z=0. Faithfulness follows. Finite positive contractions in the two corners combine to an increasing finite positive contraction net with supremum 11. Thus WG proves semifiniteness.

For any x∈nρx\in\mathfrak n_\rho, ρ(x∗x)=ρ(ex∗xe)+ρ(fx∗xf).(SI.17) \rho(x^*x)=\rho(ex^*xe)+\rho(fx^*xf). \tag{SI.17} It follows that xe,xf∈nρxe,xf\in\mathfrak n_\rho and that their GNS vectors give an orthogonal decomposition of Λρ(x)\Lambda_\rho(x). Polarization proves that (SI.13) extends to complementary orthogonal projections. They commute with every left multiplier. Likewise Le,LfL_e,L_f are complementary orthogonal projections. This proves the four-space decomposition.

Proof of the domain assertions. Compression x↦ixjx\mapsto ixj preserves the finite-star domain: its GNS norm is bounded by that of xx, and the same holds after taking adjoints. On this domain, adjunction gives (SI.14). Approximate an arbitrary ξ∈D(Sρ)\xi\in D(S_\rho) in the full graph norm by finite-star GNS vectors and compress them. Closedness gives (SI.14) and proves (SI.16). Applying Sρ2=1S_\rho^2=1 on its domain gives the stated bijection.

The adjoint pairing for this orthogonal decomposition makes Sρ∗S_\rho^* exchange the same pair of corners in the reverse direction. Hence Sρ∗SρS_\rho^*S_\rho reduces every corner and each sum of corners defining Li,QjL_i,Q_j. On the dense domain, SρLi=QiSρS_\rho L_i=Q_iS_\rho. In its polar decomposition Sρ=JρΔρ1/2S_\rho=J_\rho\Delta_\rho^{1/2}, the square root commutes with LiL_i and has dense range. Thus JρLi=QiJρJ_\rho L_i=Q_iJ_\rho, first on that range and then everywhere. This proves (SI.15). ∎

The iiii corner, with map x↦Λρ(x)x\mapsto\Lambda_\rho(x) for x∈iLi∩nρx\in iLi\cap\mathfrak n_\rho, is exactly the GNS space of the corresponding corner weight. Its restricted S,J,ΔS,J,\Delta are therefore that weight's modular data. In particular σtρ(e)=e\sigma_t^\rho(e)=e, σtρ(f)=f\sigma_t^\rho(f)=f, and the corner restrictions of σtρ\sigma_t^\rho are σtα,σtβ\sigma_t^\alpha,\sigma_t^\beta. This conclusion uses the actual GNS and graph-core identifications above.

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

For now assume that φ\varphi is NSF on MM. On K⊕HK\oplus H, define N={πψ(y)⊕y:y∈N},L=N′,(SI.18) \mathcal N=\{\pi_\psi(y)\oplus y:y\in N\}, \qquad L=\mathcal N', \tag{SI.18} and let e,fe,f project onto K,HK,H. The diagonal representation is faithful and normal. WH-02 makes its image a von Neumann algebra, so L′=NL'=\mathcal N. Its corners are eLe=B,fLf=M,fLe=X.(SI.19) eLe=B,\qquad fLf=M,\qquad fLe=\mathcal X. \tag{SI.19} Both ee and ff have central support 11 in LL: a central projection annihilating either coordinate belongs to L′=NL'=\mathcal N, and faithfulness of that coordinate representation makes it zero.

Apply SI-05 with α=χ=ψopp\alpha=\chi=\psi^{\mathrm{opp}}, β=φ\beta=\varphi. Its first column QeHρ=Hee⊕HfeQ_eH_\rho=H_{ee}\oplus H_{fe} identifies with K⊕HK\oplus H by Λρ(b0X0)⟼Γ(b)⊕η(X).(SI.20) \Lambda_\rho\begin{pmatrix}b&0\\X&0\end{pmatrix} \longmapsto\Gamma(b)\oplus\eta(X). \tag{SI.20} Indeed the finite condition is exactly χ(b∗b)<∞\chi(b^*b)<\infty, χ(X∗X)<∞\chi(X^*X)<\infty, and (SI.5), (SI.11) give equality of squared norms. The range is dense: Γ(nχ)\Gamma(\mathfrak n_\chi) is dense in KK, and DψD_\psi is dense in HH by SC. The map therefore extends to a unitary.

This unitary intertwines the entire left action of LL. To see this without an unproved module formula, identify a finite column ZZ with the map K→K⊕HK\to K\oplus H satisfying ZΛψ(y)=(πψ(y)⊕y)ζ, Z\Lambda_\psi(y)=(\pi_\psi(y)\oplus y)\zeta, where ζ\zeta is its image in (SI.20). For a∈La\in L, the column aZaZ has the same equation with aζa\zeta. The finite left ideal is stable under aa, and uniqueness in SI-04 identifies its vector. Thus (SI.20) carries πρ(a)\pi_\rho(a) to aa.

Under this identification, Δρit∣QeHρ=Δψ−it⊕Ut,(SI.21) \Delta_\rho^{it}|_{Q_eH_\rho} =\Delta_\psi^{-it}\oplus U_t, \tag{SI.21} for a strongly continuous unitary group UtU_t on H=HfeH=H_{fe}. The first component is SI-02, and the two components are reducing by SI-05. We next identify the generator of the second component.

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

Let Kφ,ψ=HefK_{\varphi,\psi}=H_{ef}. For Eφ,ψ={ξ∈Dψ:φ(θψ(ξ))<∞},(SI.22) E_{\varphi,\psi}=\{\xi\in D_\psi: \varphi(\theta_\psi(\xi))<\infty\}, \tag{SI.22} define the antilinear map Tφ,ψ0ξ=Λρ(Rψ(ξ)∗)∈Hef.(SI.23) T^0_{\varphi,\psi}\xi =\Lambda_\rho(R_\psi(\xi)^*)\in H_{ef}. \tag{SI.23} Here Rψ(ξ)R_\psi(\xi) is placed in the fefe operator corner. The source and target Hilbert spaces in this formula are different.

Theorem. The map is closable, its closure Tφ,ψT_{\varphi,\psi} is the restricted closed Tomita block of SI-05, and D(Tφ,ψ)=Vφ=D(A1/2),Tφ,ψ∗Tφ,ψ=A,(SI.24) D(T_{\varphi,\psi})=V_\varphi=D(A^{1/2}), \qquad T_{\varphi,\psi}^*T_{\varphi,\psi}=A, \tag{SI.24} where A=dφ/dψA=d\varphi/d\psi denotes SC's direct operator. Its polar factor Cφ,ψ=Jρ∣Hfe:H⟶Kφ,ψ(SI.25) C_{\varphi,\psi}=J_\rho|_{H_{fe}}:H\longrightarrow K_{\varphi,\psi} \tag{SI.25} is antiunitary, and Tφ,ψ=Cφ,ψA1/2,A=Δρ∣Hfe.(SI.26) T_{\varphi,\psi}=C_{\varphi,\psi}A^{1/2}, \qquad A=\Delta_\rho|_{H_{fe}}. \tag{SI.26}

Proof. SI-04 identifies all finite fefe columns with DψD_\psi. An fefe operator XX is in the finite-star domain precisely when both χ(X∗X)\chi(X^*X) and φ(XX∗)\varphi(XX^*) are finite. Thus (SI.22) corresponds to exactly the graph core (SI.16), not merely a subspace of it. On that core the Tomita map is (SI.23), and ∥Tφ,ψ0ξ∥2=ρ(Rψ(ξ)Rψ(ξ)∗)=φ(θψ(ξ)).(SI.27) \|T^0_{\varphi,\psi}\xi\|^2 =\rho(R_\psi(\xi)R_\psi(\xi)^*) =\varphi(\theta_\psi(\xi)). \tag{SI.27} The graph norm of this map is consequently SC's initial form norm. SI-05 proves that its graph closure is the entire restricted block. Its closed energy form is therefore the canonical completion of the same initial form used in SC. Uniqueness of that completion and of the represented operator gives (SI.24). The reducing-corner polar decomposition gives (SI.25–26). Both corners are exchanged by the involutive antiunitary JρJ_\rho, so this polar factor is onto. ∎

In particular Ut=AitU_t=A^{it} in (SI.21). The identification is a consequence of equality of the actual closed graph completions; using the same symbol for two constructions would not prove it.

OA-MOD-SI-08. The two modular actions and the relative conjugation

Theorem. For NSF φ,ψ\varphi,\psi, the positive operator AA is injective and AitxA−it=σtφ(x)(x∈M),(SI.28) A^{it}xA^{-it}=\sigma_t^\varphi(x)\quad(x\in M), \tag{SI.28} AityA−it=σ−tψ(y)(y∈N).(SI.29) A^{it}yA^{-it}=\sigma_{-t}^\psi(y)\quad(y\in N). \tag{SI.29}

Proof. SC identifies the kernel as fφH=0f_\varphi H=0. On the first GNS column, MF and (SI.21) show that Δψ−it⊕Ait\Delta_\psi^{-it}\oplus A^{it} normalizes LL. Its action on the ffff corner is σtφ\sigma_t^\varphi, by SI-05, proving (SI.28).

The same unitary therefore normalizes L′=NL'=\mathcal N. For y∈Ny\in N, its first diagonal component after conjugation is Δψ−itπψ(y)Δψit=πψ(σ−tψ(y)). \Delta_\psi^{-it}\pi_\psi(y)\Delta_\psi^{it} =\pi_\psi(\sigma_{-t}^\psi(y)). Faithfulness of πψ\pi_\psi determines the element of NN in this diagonal operator. Its second component must be σ−tψ(y)\sigma_{-t}^\psi(y), proving (SI.29). ∎

The relative conjugation can also be specified as an action between corners. Put jψ(y)=Jψπψ(y∗)Jψ∈B.(SI.30) j_\psi(y)=J_\psi\pi_\psi(y^*)J_\psi\in B. \tag{SI.30} This is a complex-linear *-anti-isomorphism N→BN\to B. On the first column, the right action of b∈eLe=Bb\in eLe=B is R(b)=Jρπρ(b∗)Jρ. \mathcal R(b)=J_\rho\pi_\rho(b^*)J_\rho. On its eeee component, SI-02 gives the action Jψb∗JψJ_\psi b^*J_\psi. Hence R(jψ(y))=πψ(y)⊕y.(SI.31) \mathcal R(j_\psi(y))=\pi_\psi(y)\oplus y. \tag{SI.31} To justify the second component, both operators commute with LL, so belong to N\mathcal N; their first components agree, and that component is faithful. Consequently, with C=Cφ,ψC=C_{\varphi,\psi}, CyC−1=πρ(jψ(y)∗)∣Hef,(SI.32) C y C^{-1}=\pi_\rho(j_\psi(y)^*)|_{H_{ef}}, \tag{SI.32} CxC−1=Jρπρ(x)Jρ∣Hef(x∈M=fLf).(SI.33) C x C^{-1} =J_\rho\pi_\rho(x)J_\rho|_{H_{ef}} \quad(x\in M=fLf). \tag{SI.33} The latter is the right fLffLf-action corresponding to x∗x^*. These are conjugate-linear transformations of algebras, as required by the antiunitary CC. They specify the two actions without postulating a modular conjugation H→HH\to H for the given representation.

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

Let ω,φ\omega,\varphi be NSF weights on an abstractly identified von Neumann algebra MM. Represent MM faithfully on HωH_\omega, and use ωopp\omega^{\mathrm{opp}} as the denominator on its commutant. By SI-02 its GNS space canonically identifies with HωH_\omega, and its opposite weight is ω\omega. The linking algebra is therefore M2(M)M_2(M), with diagonal weight ω⊕φ\omega\oplus\varphi.

For a column jj, every one of its two row spaces identifies with HωjH_{\omega_j}, where ω1=ω\omega_1=\omega, ω2=φ\omega_2=\varphi, through Λωj(x)⟼Λω⊕φ(xEij).(SI.53) \Lambda_{\omega_j}(x)\longmapsto\Lambda_{\omega\oplus\varphi}(xE_{ij}). \tag{SI.53} The norm equality is immediate from the jjjj diagonal of (xEij)∗(xEij)(xE_{ij})^*(xE_{ij}); the full finite-left ideal gives dense range. The off-diagonal Tomita block from column 11 to column 22 is therefore the closure of Sφ,ω0Λω(x)=Λφ(x∗),x∈nω∩nφ∗.(SI.54) S^0_{\varphi,\omega}\Lambda_\omega(x) =\Lambda_\varphi(x^*), \qquad x\in\mathfrak n_\omega\cap\mathfrak n_\varphi^*. \tag{SI.54} Its initial domain is dense, and it is a graph core for its closure by SI-05, applied to this exact matrix corner. The reverse block is the inverse on its actual range, because the full closed Tomita map is involutive. In particular both block polar factors are antiunitaries, inverse to one another, and Sφ,ω∗Sφ,ω=d(φ∘πω−1)dωoppon Hω.(SI.55) S_{\varphi,\omega}^*S_{\varphi,\omega} =\frac{d(\varphi\circ\pi_\omega^{-1})}{d\omega^{\mathrm{opp}}} \quad\text{on }H_\omega. \tag{SI.55} This proves the ordinary relative-modular identification with the direct spatial derivative, including the mixed finite-star graph core. It does not identify the two GNS spaces by an unconstructed common natural cone. Such a standard-form identification is a further possible representation of these already specified maps.

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

Let φ1,φ2\varphi_1,\varphi_2 be NSF on MM, and put Aj=dφj/dψA_j=d\varphi_j/d\psi. Define ut=A2itA1−it.(SI.60) u_t=A_2^{it}A_1^{-it}. \tag{SI.60} These are bounded products of unitaries. By (SI.29), their conjugations on NN cancel, so ut∈N′=Mu_t\in N'=M. They are strongly* continuous in tt. Direct multiplication gives us+t=usσsφ1(ut),σtφ2(x)=utσtφ1(x)ut∗.(SI.61) u_{s+t}=u_s\sigma_s^{\varphi_1}(u_t), \qquad \sigma_t^{\varphi_2}(x)=u_t\sigma_t^{\varphi_1}(x)u_t^*. \tag{SI.61} For example, in the first identity replace σsφ1\sigma_s^{\varphi_1} by conjugation with A1isA_1^{is}. The adjacent factors A1−isA1isA_1^{-is}A_1^{is} and A1−itA1−isA_1^{-it}A_1^{-is} then give exactly (SI.60) at s+ts+t. No commutation between A1A_1 and A2A_2 is used.

To prove reference independence, define the intrinsic weight Φ([xij])=φ1(x11)+φ2(x22)on M2(M)+.(SI.62) \Phi([x_{ij}])=\varphi_1(x_{11})+\varphi_2(x_{22}) \quad\text{on }M_2(M)_+. \tag{SI.62} Represent this algebra on H⊕HH\oplus H. Its commutant is {y⊕y:y∈N}\{y\oplus y:y\in N\}: commuting with the scalar matrix units first forces this diagonal shape, and commuting with diagonal copies of MM then gives y∈Ny\in N. Use ψ\psi on this commutant. A vector (ξ1,ξ2)(\xi_1,\xi_2) is bounded exactly when both components are in DψD_\psi; its coefficient is the matrix [Rψ(ξi)Rψ(ξj)∗][R_\psi(\xi_i)R_\psi(\xi_j)^*]. Thus its finite energy is qφ1[ξ1]+qφ2[ξ2]. q_{\varphi_1}[\xi_1]+q_{\varphi_2}[\xi_2]. The product of the two SC cores is a core for this orthogonal sum, by separate graph approximation of its two components. Therefore dΦdψ=A1⊕A2.(SI.63) \frac{d\Phi}{d\psi}=A_1\oplus A_2. \tag{SI.63} Apply (SI.28) to this amplified pair. With E21E_{21} the scalar matrix unit, σtΦ(E21)=utE21.(SI.64) \sigma_t^\Phi(E_{21})=u_tE_{21}. \tag{SI.64} The left side is defined from the weight's intrinsic GNS modular group by MF; it contains no reference ψ\psi. Hence (SI.60) is independent of the NSF commutant reference. It is also independent of the faithful normal concrete realization of MM: a normal *-isomorphism transports the weight's entire GNS map and its finite-star graph core, and hence its S,J,ΔS,J,\Delta and modular group. The transported matrix-unit identity is (SI.64).

We may therefore define the balanced-matrix weight cocycle by [Dφ2:Dφ1]tE21=σtφ1⊕φ2(E21).(SI.65) [D\varphi_2:D\varphi_1]_tE_{21} =\sigma_t^{\varphi_1\oplus\varphi_2}(E_{21}). \tag{SI.65} Then the spatial formula is the exact identity A2it=[Dφ2:Dφ1]tA1it.(SI.66) A_2^{it}=[D\varphi_2:D\varphi_1]_t A_1^{it}. \tag{SI.66} This is the balanced-weight construction used for the source cocycle. The full analytic/KMS characterization of this family, its uniqueness among families satisfying that characterization, and converse reconstruction from an arbitrary cocycle are separate theorems. None is needed to establish (SI.61), (SI.64–66).

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