CPT and spin-statistics proof interface

A CPT/spin-statistics proof interface is the minimum set of typed data, hypotheses, and proof obligations that must be fixed before a scalar or spinor Wightman CPT or spin-statistics theorem is stated. It is a checklist, not a sufficiency theorem, and it asserts neither conclusion.

The proposed field system must specify a nonzero complex Hilbert space $\mathcal{H}$ as in “Hilbert space”, with inner product linear in its first argument as in “Real and complex inner-product spaces and their induced length”, a dense complex linear field domain ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}\subseteq \mathcal{H}$, and a finite-dimensional complex component space $V$ with $1\le {\dim }_{\mathbb{C}}V<\mathrm{\infty }$, together with a distinguished unit vector $\mathrm{\Omega }\in {\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$. A field multiplet is a finite family of complex-linear maps on Schwartz test functions, with the Schwartz topology of “Schwartz space and its seminorms” and the Poincaré pullback convention of “Proper-orthochronous Poincaré action and test pullback”: ${\mathrm{\Phi }}_{\alpha }:\mathcal{S}({\mathbb{R}}^4;\mathbb{C})\to \mathrm{Lin}({\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}})$, where $\mathrm{Lin}({\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}})$ is the vector space of linear maps from that domain to itself. Each field map preserves ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$ and is weakly tempered: for every $u,v\in {\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$, $f\mapsto ({\mathrm{\Phi }}_{\alpha }(f)u,v)$ is a continuous linear functional on Schwartz space. Every finite product on ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$ must be defined. For $g=(A,a)$, use $T_{g}f(x)=f(\mathrm{\Lambda }(A{)}^{-1}(x-a))$. The Poincaré pullback continuity lemma guarantees $T_{g}f\in \mathcal{S}$ and continuity of $T_g$ and $T_{g^{-1}}$ in the Schwartz topology, so field covariance with these transformed tests is defined on the declared domain. The associated $n$-point function is the multilinear functional $(f_1,\dots ,f_n)⟼({\mathrm{\Phi }}_{{\alpha }_1}(f_1)\cdots {\mathrm{\Phi }}_{{\alpha }_n}(f_n)\mathrm{\Omega },\mathrm{\Omega });$ the interface must require and identify its continuous extension to $\mathcal{S}({\mathbb{R}}^{4n};\mathbb{C})$ for each component sequence.

The domain must satisfy $U(g){\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}={\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$ for every group element $g$. The symmetry data must include a strongly continuous unitary group representation $U$ of the spin-cover Poincaré group ${\tilde{P}}_{+}^{\uparrow }:=SL(2,\mathbb{C})⋉{\mathbb{R}}^4$, with product $(A,a)(B,b)=(AB,a+\mathrm{\Lambda }(A)b)$. Give $SL(2,\mathbb{C})$ its subspace topology from $M_2(\mathbb{C})$ and the semidirect product the product topology. Here $SL(2,\mathbb{C})=\{A\in M_2(\mathbb{C}):\det A=1\}$, and $GL(V)$ denotes the invertible complex-linear maps on $V$. The specified continuous surjective double-cover homomorphism $\mathrm{\Lambda }:SL(2,\mathbb{C})\to S{O}^{+}(1,3)$ has kernel $\{I,-I\}$; $-I$ is the central order-two kernel element called the $2\pi$-rotation element here. $S{O}^{+}(1,3)$ and the affine translation conventions are those of the Poincaré supplier. Each $U(g)$ is a surjective linear isometry of $\mathcal{H}$, $U(gh)=U(g)U(h)$, and $g\mapsto U(g)\xi$ is norm-continuous for each fixed $\xi \in \mathcal{H}$. The field system also specifies a continuous finite-dimensional representation $S:SL(2,\mathbb{C})\to GL(V)$, so $S(AB)=S(A)S(B)$ and $S(I)=I$. Its field covariance identity must be stated explicitly as an equality in $\mathrm{Lin}({\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}})$ and checked against the group law. It must identify whether the component matrix is $S$, its dual, or its complex conjugate and fix the test-function pullback or its inverse, the adjoint convention, and all component indices. The vacuum $\mathrm{\Omega }$ must be invariant under translations, with translation-invariant subspace exactly $\mathbb{C}\mathrm{\Omega }$, and cyclic: the span of all vectors ${\mathrm{\Phi }}_{{\alpha }_1}(f_1)\cdots {\mathrm{\Phi }}_{{\alpha }_n}(f_n)\mathrm{\Omega }$, including $\mathrm{\Omega }$, is dense in $\mathcal{H}$.

The positive-energy premise must be the joint PVM input of “Positive-energy joint spectral input”, including its Countable Choice assumption, on this same $\mathcal{H}$ with this same $\mathrm{\Omega }$. Denote its translation representation by $U_{\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}}$ and require $U((I,a))=U_{\mathrm{s}\mathrm{p}\mathrm{e}\mathrm{c}}(a)={\mathrm{\Phi }}_E(p\mapsto e^{ip\cdot a})(a\in {\mathbb{R}}^4)\mathrm{.}$ For $f,g\in \mathcal{S}({\mathbb{R}}^4;\mathbb{C})$ with compact spacelike-separated supports, the field locality identity and its sign must be stated on ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$. Here $\mathrm{supp}f$ is the closure of $\{x:f(x)\mathrm{\ne }0\}$. Spacelike separation here means $(x^0-y^0{)}^2-\mathrm{\mid }\mathbf{x}-\mathbf{y}{\mathrm{\mid }}^2<0$ for every support pair. If a proof uses weak locality, that term means the equality of the original and reversed vacuum $n$-point distributions on the specific real set of relative coordinates required by the selected theorem; the set, reversal, field grading, and distributional boundary interpretation must be stated rather than left under the name “Jost points.”

The proof interface must then identify, with the Fourier sign and relative coordinates fixed, the multivariable tube domain to which each $n$-point distribution is continued. A complexified Lorentz action here is a specified holomorphic action on ${\mathbb{C}}^4$ of a specified complex matrix group extending the real action through $\mathrm{\Lambda }$ and preserving the complex-bilinear extension of the Minkowski form. A complex Lorentz extension means a single-valued holomorphic continuation on a stated domain generated by that action; the acting group, its action, and the domain must be given and the covariance formula checked there. Any edge-of-the-wedge step must name its exact theorem, both holomorphic domains, their common distributional boundary value, the open real set where they agree, and the conclusion of uniqueness used.

A claimed CPT conclusion means the combined field transformation by charge conjugation and spacetime inversion $x\mapsto -x$ (simultaneous parity and time reversal); it must preserve ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$, define a surjective conjugate-linear isometry $\mathrm{\Theta }:\mathcal{H}\to \mathcal{H}$ (antiunitarity), state its action on $\mathrm{\Omega }$, translations, every field component, and test functions, and specify the conjugate-linear charge-conjugation map and all phases. A claimed spin-statistics conclusion must state the action $S(-I)={ϵ}_{\mathrm{s}\mathrm{p}\mathrm{i}\mathrm{n}}{I}_V$ of the central $2\pi$-rotation element $-I\in SL(2,\mathbb{C})$, with ${ϵ}_{\mathrm{s}\mathrm{p}\mathrm{i}\mathrm{n}}\in \{+1,-1\}$, and the actual spacelike exchange sign ${ϵ}_{\mathrm{l}\mathrm{o}\mathrm{c}}\in \{+1,-1\}$ in ${\mathrm{\Phi }}_{\alpha }(f){\mathrm{\Phi }}_{\beta }(g)={ϵ}_{\mathrm{l}\mathrm{o}\mathrm{c}}{\mathrm{\Phi }}_{\beta }(g){\mathrm{\Phi }}_{\alpha }(f)$ on ${\mathcal{D}}_{\mathrm{f}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}}$. For a multiplet with a single spin parity, the theorem must derive the precise relation ${ϵ}_{\mathrm{l}\mathrm{o}\mathrm{c}}={ϵ}_{\mathrm{s}\mathrm{p}\mathrm{i}\mathrm{n}}$. Any additional theorem-specific assumptions remain explicit; this interface does not claim that its checklist alone suffices.

Proper-orthochronous Poincaré pullbacks act continuously on Schwartz space

Positive-energy joint spectral input

Positive spectrum gives bounded future-tube continuation

Weak operator-valued tempered distribution on a common domain

Proper-orthochronous Poincaré action and test pullback

Schwartz space and its seminorms

Hilbert space

Real and complex inner-product spaces and their induced length

The Axiom of Countable Choice (${\mathrm{A}\mathrm{C}}_{\omega }$)

Fewster and Rejzner, §§5.1–5.2

Mund, §2.1

Álvarez-Gaumé and Vázquez-Mozo, §4

The bounded-insertion theorem Positive spectrum gives bounded future-tube continuation proves neither analyticity for unbounded field products nor the distributional boundary and uniqueness steps listed here. The published Tested positive moments reconstruct closable smeared fields supplies only its stated matrix-coefficient spectrum condition, not a joint PVM. The existing free scalar and Dirac constructions are examples and do not discharge a general CPT or spin-statistics proof obligation.