Alphabeta Math
Physics theoremStatement: AI-adaptedProof: AI-generatedPipeline-generatedprecheck passverified 2026-10-22 (gpt-6.1-sol)
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.

Exact planar Landau spectrum in the linear gauge

Physical scope

Exact spectral prediction of the adopted spinless nonrelativistic point-particle model on the infinite plane, for a constant nonzero perpendicular field in the unbounded linear Landau gauge. It makes no finite-sample degeneracy count, boundary claim, or empirical assertion.

Statement

Assume the Axiom of Choice, Countable Choice, and Dependent Choice, and the adopted spinless minimal-coupling form model. Let m>0 be mass in kilograms, q≠0 charge in coulombs, B≠0 the constant signed perpendicular field component in teslas, and ℏ>0 in joule-seconds. Let A:R2→R2 be A(x,y)=(0,Bx) in tesla-metres; then B⊥=∂xAy−∂yAx=B is its scalar perpendicular field. Take wavefunctions in L2(R2;C). Set V=0 and define the Hamiltonian by the closed form of the core expression qB[u]=12m(∥−iℏ∂xu∥22+∥(−iℏ∂y−qBx)u∥22),u∈Cc∞(R2;C). The resulting Friedrichs Hamiltonian is unitarily equivalent, under partial Fourier transformation in y followed by x=ξ+ℏk/(qB), to the constant family of oscillators h(k)=−ℏ22m∂ξ2+(qBξ)22m,k∈R, with its form-closed realization. Its spectrum is {ℏ∣qB∣m(n+12):n∈N0}. Every listed eigenvalue has infinite multiplicity, and every spectral measure is purely atomic on this set; there is no continuous spectral measure. This is a conditional model deduction, not a claim that a material realizes the ideal infinite-plane Hamiltonian.

Facts & Assumptions

Given: the Axiom of Choice, Countable Choice, Dependent Choice, the spinless model postulate, m>0, qB≠0, ℏ>0, A=(0,Bx), V=0, and the core form in the Statement. Use SI units.

[A1]

Adopt the spinless minimal-coupling assignment and the stated Friedrichs-form prescription (Unbounded vector potential and effective Pauli model).

[A2]

The Axiom of Choice and Countable Choice are hypotheses of the closed-form representation and unbounded spectral suppliers. Dependent Choice is required by the Landau form supplier (The Axiom of Choice, The Axiom of Countable Choice (ACω), The axiom of dependent choice: a relation in which every element is related to something admits an N-indexed chain, Closed-form diagonalization in Landau gauge).

[F1]

The closed magnetic form is unitarily equivalent to the diagonal form ∑nEn∥fn∥22 on coefficient families, with En=ℏ∣qB∣(n+12)/m, under the explicitly normalized partial Fourier and translation map (Closed-form diagonalization in Landau gauge).

[F2]

The closed-form representation theorem applies to a dimensionless closed form. Write Eref=1 J for the postulate's reference energy and apply the theorem to q/Eref. On the closed form domain, (q/Eref)[F]+∥F∥22=Eref−1(q[F]+Eref∥F∥22), so normalization preserves its form domain, density, and closedness. The theorem's operator domain consists of form-domain vectors F for which there is a coefficient-space vector G satisfying (q/Eref)(F,V)=⟨G,V⟩ for every form-domain vector V. If H^ represents this normalized form, then the model Hamiltonian is H=ErefH^ on the same operator domain, so its spectral values are multiplied by Eref. Here Eref is distinct from the indexed Landau level E0 used below. The theorem's exact hypotheses include the Axiom of Choice and Countable Choice (Unbounded vector potential and effective Pauli model, Semibounded closed-form representation and perturbation).

[F3]

The one-dimensional oscillator with ωc=∣qB∣/m has the complete Hermite eigenbasis and eigenvalues En=ℏωc(n+12) (Oscillator scaling and exact realization).

[F4]

A self-adjoint operator has a unique regular spectral projection-valued measure (Spectral theorem for unbounded self-adjoint operators (PVM form)).

Proof

1.1givenA1A2F1F3

The hypotheses m,ℏ>0 and qB≠0 make ωc=∣qB∣/m>0 and the translation x0(k)=ℏk/(qB) well-defined. Apply [F1]: the unitary U sends the closed form to the coefficient form q[F]=∑n=0∞En∥fn∥L2(k)2, where F(ξ,k)=∑nfn(k)ψn(ξ) and (ψn) is the complete oscillator basis from [F3]. In particular, q[F]≥E0∥F∥22>0 for nonzero F.

2.1A2F1F2step 1.1constructalgebra

Apply the closed-form representation theorem [F2] to the normalized form q^=q/Eref. If F=(fn) is in its representing operator domain, there is G=(gn) in the coefficient Hilbert space such that q^(F,V)=⟨G,V⟩ for every form-domain vector V. Fix n and take V to have sole nonzero component Vn=(En/Eref)fn−gn. It lies in the form domain because fn,gn∈L2(k) and En/Eref is finite. The representation identity gives 0=q^(F,V)−⟨G,V⟩=∥(En/Eref)fn−gn∥22, so gn=(En/Eref)fn for every n. Since G belongs to the Hilbert space, ∑n(En/Eref)2∥fn∥22<∞, equivalently ∑nEn2∥fn∥22<∞ because Eref>0.

3.1A2F1F2step 2.1algebra

Conversely, suppose F is in the form domain and ∑nEn2∥fn∥22<∞. Define Gn=(En/Eref)fn, which is a vector in the coefficient Hilbert space. For every form-domain vector V=(vn), Cauchy–Schwarz gives absolute convergence and q^(F,V)=∑n(En/Eref)⟨fn,vn⟩=∑n⟨Gn,vn⟩=⟨G,V⟩. Thus [F2] represents the normalized operator by (fn)↦((En/Eref)fn) on the stated domain. The model Hamiltonian is Eref times this operator and therefore acts by (fn)↦(Enfn) on that same domain; uniqueness identifies it with the postulated Hamiltonian.

4.1A2F1F3F4step 3.1algebra∎

For each n, the eigenspace at En is L2(Rk)⊗Cψn, which is infinite-dimensional; the energies are strictly increasing and tend to +∞. If z∉{En:n≥0}, then inf⁡n∣En−z∣>0 and sup⁡nEn/∣En−z∣<∞. The diagonal inverse is therefore bounded and maps into the operator domain, so z is in the resolvent. Each En is an eigenvalue, and the complete coefficient decomposition together with [F4] shows that all spectral projections are sums of eigenspace projections. Hence every spectral measure is atomic on the displayed set and the spectrum is exactly that set.

Remarks

The linear potential Ay=Bx is unbounded. The proof works with its closable quadratic form and never applies a bounded-coefficient H2 realization. The finite-rectangle degeneracy count in the cited treatments depends on boundary conditions; no exact hard-wall or finite-area count is claimed here.

Depends on

Dependency tree · 2 levels

Sources