Alphabeta Math
ExampleConstruction: AI-adaptedVerification: AI-adaptedPipeline-generated
How statement and proof provenance work

The first chip identifies the source of the statement or construction; the second identifies the source of its local proof or verification.

  • Literature-sourced: the exact statement appears in a cited source; only wording and notation differ.
  • AI-adapted: a semantically identical restatement of literature-sourced material, modulo indexing, notation, and boundary cases adopted by the library.
  • AI-generated: a genuinely novel statement formulated by AI, with no source for the claim itself.

These labels describe origin, not correctness: citations and verification chips remain separate evidence.

Coupled triplet and singlet

Example

Assume the Axiom of Countable Choice (The Axiom of Countable Choice (ACω)). Let V=C2 carry the orthonormal basis (e+,e−) and let (Jx(1/2),Jy(1/2),Jz(1/2)) be the spin-12 operators of Finite spin matrices, so that Ji(1/2)=12σi and J±(1/2)=Jx(1/2)±iJy(1/2) satisfy J+(1/2)e+=0, J+(1/2)e−=e+, J−(1/2)e+=e− and J−(1/2)e−=0. On V⊗^V (inner product of Hilbert tensor construction: inner product, completion and product bases) put, as in Tensor spin composition, Jitot:=Ji(1/2)⊗I2+I2⊗Ji(1/2),J±tot:=Jxtot±iJytot,Jtot 2:=(Jxtot)2+(Jytot)2+(Jztot)2, and define w1,1:=e+⊗e+,w1,0:=e+⊗e−+e−⊗e+2,w1,−1:=e−⊗e−,w0,0:=e+⊗e−−e−⊗e+2. Then:

(a) (w1,1,w1,0,w1,−1,w0,0) is an orthonormal basis of V⊗^V;

(b) the triplet vectors satisfy Jztotw1,m=m w1,m and Jtot 2w1,m=2 w1,m for m∈{1,0,−1}, while the singlet satisfies Jitotw0,0=0 for each i∈{x,y,z} and Jtot 2w0,0=0;

(c) the ladder actions on the triplet are J+totw1,1=0, J+totw1,0=2 w1,1 and J+totw1,−1=2 w1,0, together with the adjoint relations J−totw1,−1=0, J−totw1,0=2 w1,−1 and J−totw1,1=2 w1,0; hence the correspondence em↔w1,m is a unitary isomorphism of the spin-1 model of Finite spin matrices onto the triplet span, so the orthogonal decomposition of Tensor spin composition (b) is here V⊗^V=span⁡{w1,1,w1,0,w1,−1}⊕span⁡{w0,0} with parameters j=1 and j=0 and dimensions 3+1=4, summing to (2⋅12+1)2.

All claims are finite-dimensional linear-algebra statements; no physical interpretation of the vectors as particle states is asserted.

Facts & Assumptions

Given: the spin-half operators on V=C2 with basis (e+,e−), the tensor product and the total operators Jitot,J±tot, and the four vectors w1,1,w1,0,w1,−1,w0,0.

[F1]

Spin-half data (Finite spin matrices): Jz(1/2)e±=±12e±, J+(1/2)e+=0, J+(1/2)e−=e+, J−(1/2)e+=e−, J−(1/2)e−=0, J±(1/2)=Jx(1/2)±iJy(1/2), the operators Ji(1/2) are self-adjoint, and J(1/2)2=Jx(1/2)2+Jy(1/2)2+Jz(1/2)2=34I2.

[F2]

Tensor calculus (Hilbert tensor construction: inner product, completion and product bases, Linear map between vector spaces over the same field): (S⊗T)(u⊗v)=(Su)⊗(Tv) on elementary tensors, operators are extended linearly, and ⟨u⊗v,u′⊗v′⟩=⟨u,u′⟩⟨v,v′⟩; hence the four displayed vectors are pairwise orthogonal with ∥w1,1∥=∥w1,−1∥=1 and ∥w1,0∥=∥w0,0∥=1 by direct expansion of the two-term sums; four orthonormal vectors in the four-dimensional space V⊗^V form an orthonormal basis (The induced length is a norm, Cauchy–Schwarz: ∣⟨u,v⟩∣≤∥u∥∥v∥, with equality exactly for linearly dependent vectors).

[F3]

The total operators satisfy Jztot=Jz(1/2)⊗I2+I2⊗Jz(1/2) and J±tot=J±(1/2)⊗I2+I2⊗J±(1/2) by bilinearity of the tensor product, and Jtot 2=J−totJ+tot+(Jztot)2+Jztot=J+totJ−tot+(Jztot)2−Jztot by the algebraic identities of Tensor spin composition (a) (or, directly, of Finite spin matrices (b),(c) applied to the sums).

[F4]

Composition theorem (Tensor spin composition (b),(e)): for s=t=12 the space V⊗^V decomposes orthogonally into Jtot-invariant summands of dimensions 2j+1 for j=0,1, on each of which the total operators are unitarily equivalent to the spin-j model; the summand with j=1 contains the unique (up to phase) unit vector of Jztot-eigenvalue 1, and the summand with j=0 is the kernel of all three Jitot.

Verification

1.1F2algebra

[(a) orthonormality] By [F2], ⟨w1,1,w1,0⟩=(⟨e+,e+⟩⟨e+,e−⟩+⟨e+,e−⟩⟨e+,e+⟩)/2=0, and similarly for all pairs: the tensors e+⊗e+, e−⊗e−, (e+⊗e−+e−⊗e+)/2 and (e+⊗e−−e−⊗e+)/2 are mutually orthogonal of norm 1 because the four tensors e±⊗e± are orthonormal and the two combined vectors are orthogonal to them and to each other. Since dim⁡(V⊗^V)=4 (Hilbert tensor construction: inner product, completion and product bases), these four vectors form an orthonormal basis.

1.2F1F3algebra

[(b) triplet] By [F1] and [F3]: Jztotw1,1=(Jz(1/2)e+)⊗e++e+⊗(Jz(1/2)e+)=12w1,1+12w1,1=w1,1; Jztot(e+⊗e−)=(12−12)e+⊗e−=0 and Jztot(e−⊗e+)=(−12+12)e−⊗e+=0, so Jztotw1,0=0; and Jztotw1,−1=−w1,−1. Moreover J+totw1,1=0 (both terms vanish by [F1]), so J−totJ+totw1,1=0; hence Jtot 2w1,1=(0+12+1)w1,1=2w1,1 by [F3].

1.3F1F3algebra

[(b) singlet] Jztotw0,0=(12e+⊗e−+12e−⊗e+−12e+⊗e−−12e−⊗e+)/2=0; moreover J+totw0,0=(J+(1/2)e+⊗e−+e+⊗J+(1/2)e−−J+(1/2)e−⊗e+−e−⊗J+(1/2)e+)/2=(0+e+⊗e+−e+⊗e+−0)/2=0 and J−totw0,0=(J−(1/2)e+⊗e−+e+⊗J−(1/2)e−−J−(1/2)e−⊗e+−e−⊗J−(1/2)e+)/2=(e−⊗e−+0−0−e−⊗e−)/2=0 by [F1] and [F3]. Hence Jitotw0,0=0 for all i, since Jxtot=12(J+tot+J−tot) and Jytot=12i(J+tot−J−tot), and consequently Jtot 2w0,0=0.

2.1step 1.1step 1.2step 1.3F1F2F3F4algebra∎

[(c) ladder] Using [F1] and [F3]: J+totw1,1=(J+(1/2)e+)⊗e++e+⊗(J+(1/2)e+)=0; J+totw1,0=[(J+(1/2)e+)⊗e−+e+⊗(J+(1/2)e−)+(J+(1/2)e−)⊗e++e−⊗(J+(1/2)e+)]/2=(0+e+⊗e++e+⊗e++0)/2=2 w1,1; and J+totw1,−1=(J+(1/2)e−)⊗e−+e−⊗(J+(1/2)e−)=e+⊗e−+e−⊗e+=2 w1,0. Since J−tot=(J+tot)∗ ([F1] self-adjointness and [F3]), the adjoint relations follow: J−totw1,−1=0, J−totw1,0=2w1,−1, J−totw1,1=2w1,0 (each verified by pairing with the orthonormal basis vectors of step 1.1). Together with step 1.2 this shows that sending em↦w1,m carries the spin-1 operators of Finite spin matrices to Jxtot,Jytot,Jztot on the triplet: the spin-1 model has J+e0=2e1, J+e−1=2e0, J+e1=0 and Jzem=mem, matching steps 1.2 and this step, and Jx,Jy are recovered from J±; the singlet span is orthogonal to the triplet by step 1.1 and is annihilated by all Jitot by step 1.3, so this is exactly the decomposition of [F4] for s=t=12.

Depends on

Dependency tree · 2 levels

Sources