Alphabeta Math
Physics theoremStatement: AI-adaptedProof: AI-adaptedprecheck pass
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.

Orbital angular momentum eigenstates of the massive model: spherical harmonics, the l,m quantum numbers and the Casimir value

Physical scope

A conditional consequence of P1, P2, P5 and P6 for the massive spin-s model and its orbital generators: for a smooth compactly supported radial profile times a spherical harmonic, the model vector is an eigenvector of the third orbital generator with eigenvalue hbar m, the Casimir quadratic form takes the value hbar^2 l(l+1), and the orbital quantum numbers are those of the spherical harmonic family. The statement concerns the spatial factor only, uses no dynamics and no measurement model, and asserts no spectral decomposition of the full spatial Hilbert space, no hydrogen spectrum and no empirical result.

Statement

Adopt the state and composition postulate P1, the observable and probability postulate P2, the kinematics and massive-particle model postulate P5 and the internal-factor assignment of the spin postulate P6, read for the massive spin-s model of The massive spin-s particle model of the framework: state space, operators, units and frame readings and the angular momentum readings of Orbital, spin and total angular momentum of the massive spin-s model: assigned sharp observables, units and readings (State and composition postulate P1: Hilbert spaces, preparations and composite systems, Observable and probability postulate P2: self-adjoint observables, spectral probability and finite unsharp outcomes, Kinematics and massive-particle model postulate P5: Newtonian frames and one-particle operators, Identical-particle and spin assignments P6: permutation sectors and finite-spin representations), and assume the Axiom of Choice and the Axiom of Countable Choice (The Axiom of Choice, The Axiom of Countable Choice (ACω)). Fix l≥0, m∈{−l,…,l}, a unit vector w∈Cr and a complex-valued R∈Cc∞((0,∞)), and let hlm be the harmonic homogeneous polynomial of degree l with hlm∣S2=Ylm of Harmonic polynomial dimension clause (c) (Associated Legendre function normalization). Define the model vector ψ(x):=R(∣x∣) hlm(x) w(x∈R3, x≠0),ψ(0):=0. Then:

(a) ψ is a well-defined class in the model's state space Hs and in fact ψ∈Cc∞(R3;Cr)⊆S(r); it lies in D(Li) for each i, and for x≠0 (Liψ)(x)=R(∣x∣) (−iℏ Dihlm)(x) w,Dihlm=(x×∇hlm)i, so that −iℏDihlm is the polynomial representative of the sphere function LisphYlm of Orbital self-adjoint generators; in particular L3ψ=ℏm ψ;

(b) with ∥R∥l2:=∫0∞∣R(r)∣2r2l+2 dr one has ∥ψ∥2=∥R∥l2 and ∥Liψ∥2=∥R∥l2 ∥LisphYlm∥2,∑i=13∥Liψ∥2=ℏ2l(l+1) ∥ψ∥2, so the Casimir quadratic form of the model's orbital generators on ψ takes the value ℏ2l(l+1);

(c) consequently, for the pure preparation of the unit vector ψ/∥ψ∥ (for R≢0), the mean and the second moment of the outcome law of (L3,J s) are finite and equal ℏm and ℏ2m2, so the variance vanishes; for each i the mean and second moment of the law of Li are finite and the second moment equals ∥LisphYlm∥2; the model reads (l,m) as the orbital angular momentum quantum numbers of the preparation, in the sense of the eigenvalue of the angular momentum-squared form and the eigenvalue of L3;

(d) Scope. Clauses (a)-(c) are conditional consequences of P1, P2, P5, P6 and the cited mathematics, and concern the spatial factor of the massive model. The item asserts no dynamics, no measurement or apparatus model, no joint sharp values of two different components Li,Lj, no empirical value and no spectral resolution of L2(R3): the identity ∑iLi2=ℏ2l(l+1) is a quadratic-form statement on the displayed smooth vectors and is not read as a statement about a self-adjoint operator ∑iLi2 on the full spatial Hilbert space.

Facts & Assumptions

Given: The postulates P1, P2, P5 and P6 in the stated readings; the Axiom of Choice and the Axiom of Countable Choice; the model with parameters m>0, s, r=2s+1; the harmonic polynomial hlm and the sphere functions Ylm; the radial function R; the unit vector w; the vector ψ; indices i,k.

[F1]

Harmonic polynomial and spherical harmonic. For l≥0 and −l≤m≤l the polynomial hlm is homogeneous of degree l, harmonic, nonzero, with hlm∣S2=Ylm, and D3hlm=im hlm where D3=x1∂2−x2∂1; moreover L3sphYlm=ℏmYlm and LisphYlm=resl(−iℏDihlm) for Dip=(x×∇p)i (Harmonic polynomial dimension clause (c), Orbital self-adjoint generators clauses (a),(c), Associated Legendre function normalization clause (c)).

[F2]

Core action of the orbital generators. For every componentwise Schwartz class φ∈S(r) the orbital generators satisfy Liφ∈Hs, S(r)⊆D(Li), and Liφ=−iℏ∑j(ei×x)jDjφ=∑j,kεijkQjPkφ, with Dj the componentwise weak derivative (Coordinate-rotation generators on the Schwartz classes and their commutators clauses (a),(b), Componentwise position and momentum operators on the component-valued wave-function space clauses (a),(c)).

[F3]

Orbital Casimir identity. For F∈Vl one has ∑iLi2F=ℏ2l(l+1)F on the harmonic span, and the on-shell values are exactly the squared norms ∑i∥LisphYlm∥2=ℏ2l(l+1) (The orbital Casimir identity: the restrictions of the orbital generators to the degree-l blocks are spin-l models clauses (b),(c), Orbital self-adjoint generators).

[F4]

Polar integration and the sphere measure. For a Borel f≥0 on R3 one has ∫R3f dx=∫0∞∫S2f(rΩ) r2dσ(Ω) dr, and ∫S2F dσ=∫(0,π)×(0,2π)F∘Φ sin⁡θ d(θ,φ) with σ(S2)=4π (Polar coordinates decompose Lebesgue measure into r^{n-1} dr d sigma, Sphere integrals in angle coordinates).

[F5]

Schwartz calculus and the class reading. Cc∞(R3;Cr)⊆S(r); a classical partial derivative of a C1 function that is locally integrable is its weak derivative; the model space consists of almost-everywhere classes (Schwartz space and its seminorms, Componentwise position and momentum operators on the component-valued wave-function space, The space Lp(μ) as the quotient by null functions, Complex Lp classes and Euclidean test-function conventions, Hilbert space, Real and complex inner product spaces, with the inner product linear in the first argument).

Proof

Proof technique: direct; the vector is a compactly supported smooth class with a homogeneous polynomial angular factor, so the core identity of the generators applies; the radial and angular integrals separate by polar integration and the Casimir value is transported from the sphere.

Given: The data of the statement and [F1]-[F5].

1.1F1F5algebra

[Smoothness and the polynomial identity] Since supp⁡R⊆[a,b] with 0<a≤b<∞ and hlm is a polynomial, the function ψ=R(∣x∣)hlm(x)w vanishes identically near 0 and is smooth on R3 with compact support, so ψ∈Cc∞(R3;Cr)⊆S(r) by [F5]; for x≠0 and each i, the product rule gives (x×∇)iψ=R(∣x∣)(Dihlm)(x)w because (x×∇)iR(∣x∣)=R′(∣x∣) (x×x)i/∣x∣=0, and by [F1] the function −iℏDihlm is the polynomial representative of LisphYlm; moreover [F1] gives D3hlm=im hlm.

2.1step 1.1F1F2F5algebra

[Core action and L3 eigenvalue] By step 1.1 and [F2], ψ∈D(Li) and Liψ=∑j,kεijkQjPkψ=−iℏ (x×∇)iψ=R(∣x∣) (−iℏDihlm)(x) w for almost every x, where the weak derivatives agree with the classical ones by [F5]; here Pk=−iℏ∂k on the Schwartz class, so the factor −iℏ occurs once. For i=3, [F1] gives L3ψ=−iℏR D3hlm w=ℏmR hlmw=ℏmψ, proving (a).

3.1step 2.1F1F3F4givenalgebra

[Norms and the Casimir form] Put qi:=Dihlm. Each term xj∂khlm is homogeneous of degree l or zero, so qi(rΩ)=rlqi(Ω) for r>0; for l=0, qi=0. By step 2.1, ∥w∥=1 and polar integration [F4], ∥Liψ∥2=ℏ2∫R3∣R(∣x∣)∣2∣qi(x)∣2 dx=ℏ2(∫0∞∣R(r)∣2r2l+2 dr)∫S2∣qi(Ω)∣2 dσ(Ω). By [F1], LisphYlm=−iℏqi∣S2, hence ∥Liψ∥2=∥R∥l2∥LisphYlm∥2. Likewise homogeneity of hlm and [F4] give ∥ψ∥2=∥R∥l2∫S2∣Ylm∣2 dσ=∥R∥l2, using the normalization in Associated Legendre function normalization clause (d). Finally, on the finite invariant block Vl, self-adjointness and [F3] give ∑i∥LisphYlm∥2=⟨∑i(Lisph)2Ylm,Ylm⟩=ℏ2l(l+1), so ∑i∥Liψ∥2=ℏ2l(l+1)∥ψ∥2, proving (b), including l=0 and R=0.

4.1step 2.1step 3.1F3algebra

[Readings] Let R≢0 and put φ:=ψ/∥ψ∥; by step 2.1, L3φ=ℏmφ with φ∈D(L3), so the mean and the second moment of the law of L3 in the pure preparation [φ] are ⟨L3φ,φ⟩=ℏm and ∥L3φ∥2=ℏ2m2, with variance 0; for each i, step 2.1 gives φ∈D(Li) and step 3.1 gives ∥Liφ∥2=∥LisphYlm∥2, so the mean and second moment of the law of Li are finite with that second moment, and the quadratic form is ∑i∥Liφ∥2=ℏ2l(l+1), which is (c).

5.1step 1.1step 2.1step 3.1step 4.1F2∎

[Assembly and scope] Steps 1.1 and 2.1 prove (a), step 3.1 proves (b) and step 4.1 proves (c); only the spatial core identities, the sphere data and polar integration were used, no dynamics, apparatus or empirical input entered, and no operator identity for ∑iLi2 on the full space was asserted, which is the scope statement (d).

Remarks

  • The density of the family. The vectors R(∣x∣)hlm(x)w with R∈Cc∞((0,∞)) span a dense subspace of the angular sector L2((0,∞),r2dr)⊗C Ylm⊗Cw in the polar decomposition; this theorem uses only their eigenproperty and makes no completeness claim.
  • No hidden operator (L2). The Casimir value is stated as a quadratic-form identity. Defining a self-adjoint operator ∑iLi2 on L2(R3) would require a separate closed-form and domain argument, which is not part of this page.

Depends on

Dependency tree · 2 levels

Sources