Alphabeta Math
TheoremStatement: Literature-sourcedProof: AI-adaptedPipeline-generatedjudge pass (gpt-5.6-terra)audited 2026-09-07
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.

Clifford correspondence

Statement

Let G be finite, N⊴G, θ∈Irr⁡(N), and I=IG(θ). Induction gives a bijection Irr⁡(I∣θ)⟶Irr⁡(G∣θ). On module isomorphism classes, the inverse takes the θ-isotypical component. Conjugate normal types give the same target set, and the sets Irr⁡(G∣θ), indexed by distinct G-orbits in Irr⁡(N), partition Irr⁡(G).

Facts & Assumptions

Given: The groups, modules, characters, and hypotheses in the statement. All representations here are finite-dimensional complex left representations.

[F1]

For irreducible V lying over θ, the component Vθ is irreducible over inertia and its induction is isomorphic to V. (Reconstruction from the inertia component).

[F2]

An irreducible inertia module above θ induces irreducibly, and its identity-coset block is the full θ-component, isomorphic to the original inertia module. (Induction of an inertia constituent is irreducible).

[F3]

The normal restriction of an irreducible character is a positive common multiple of the sum of the distinct conjugates of any constituent. (Clifford restriction formula).

Proof

technique · direct
1.1F1F2given

Induction sends each element of Irr⁡(I∣θ) to an irreducible lying over θ. Conversely, every irreducible V lying over θ is induced from its irreducible component Vθ. This proves that the displayed map is defined and surjective.

2.1F2step 1.1

Taking the θ-component of an induced module recovers its inducing module. A G-isomorphism preserves these components, since it sends simple N-submodules to simple submodules of the same type. Hence isomorphic induced modules have isomorphic inducing modules. This proves injectivity and the specified inverse.

3.1F3step 1.1step 2.1∎

The restriction formula shows that occurrence of one type is equivalent to occurrence of each conjugate, and excludes every type outside that orbit. Every irreducible G-module has a nonzero finite-dimensional restriction: an N-stable nonzero subspace of least possible dimension is simple, so a constituent exists. Consequently the orbit-indexed sets cover Irr⁡(G) and are pairwise disjoint. No step requires I to be proper in G or to properly contain N.

Depends on

Used by

Dependency tree · two levels

9 results within two dependency steps of this one, each drawn at its shortest distance from it. An arrow runs from a result to what uses it, so the chart reads left to right and ends at this result, which carries a heavier outline. Every node is a link to that result. Click elsewhere on the chart to enlarge it.

Sources