MATHLIBANNEX / PROJECT LFH

Unitary equivalence of irreducible representations

For a fixed supplied family and its once-chosen links, put . The maps have distinct domains:

The selected vector states give a cyclic-sum isometry . In the generated-algebra setting, root normalization and irreducibility show that the chosen isometry is surjective. The full equivalence proof uses that same underlying map after bundling it as a unitary, and additionally uses the prescribed cyclic-vector action of the links. Shell sums are compared separately on the two Hilbert spaces; strong continuity of an arbitrary representation is never assumed.

The nonunital version first proves unit preservation for the same nonzero irreducible representation. Simplicity and compact-operator exclusion are subsequent consequences. The existential unitary in a separately applied theorem need not equal a witness selected in another application.

Exact Card references

Boundary Inputs

The displayed edges preserve dependency paths through omitted helpers. Levels count selected predecessors within this scope. Mathematical citations remain distinct from formal dependencies.

Exact source and provider boundary · Earlier 466-declaration Project view and PDF

Dependency-first reading route

Levels belong to this reading scope. Follow prerequisites or uses to focus the route.

9 declarations

Level 0

Level 0Focus target

The CAR source map into the fixed shell-family target

MathlibAnnex.CStarAlgebra.CAR.shellFamilySourceHom

Restricting the codomain of the selected atomic representation gives the source map into one fixed generated target.

Level 0Focus target

The ambient inclusion of the fixed shell-family target

MathlibAnnex.CStarAlgebra.CAR.shellFamilyInclusion

The same concrete target has a literal representation on the selected atomic Hilbert space.

Immediate prerequisites in this Project
None in this scope

Used by in this Project
Closed-ideal simplicity of the shell-generated algebra, Unitary equivalence without an initial unitality assumption

Level 0Focus target

Assembling selected GNS cyclic subspaces into an isometric source representation

MathlibAnnex.CStarAlgebra.CAR.exists_selectedAtomicCyclicIsometry

Joins mutually orthogonal pure-state cyclic copies and controls the limiting flag projections on their sum.

Immediate prerequisites in this Project
None in this scope

Used by in this Project
The cyclic sum fills every irreducible target representation

Level 1

Level 1Focus target

The cyclic sum fills every irreducible target representation

MathlibAnnex.CStarAlgebra.CAR.exists_surjective_selectedAtomicCyclicIsometry

Uses shell reconstruction and residual lines to turn an isometric CAR intertwiner into a unitary equivalence on the source.

Level 1Focus target

The shell-generated algebra is not an algebra of all compact operators

MathlibAnnex.CStarAlgebra.CAR.not_isCompactOperatorModel_shellFamilyTarget

Excludes an injective representation of the infinite-dimensional unital algebra onto all compact operators.

Level 2

Level 2Focus target

Every irreducible representation is unitarily equivalent to the inclusion

MathlibAnnex.CStarAlgebra.CAR.ambientInclusion_unitaryEquivalent

Extends the unitary equivalence from the CAR source to all additional generators and the norm-closed target.

Level 3

Level 3Focus target

Unitary equivalence without an initial unitality assumption

MathlibAnnex.CStarAlgebra.CAR.shellFamilyInclusion_unitaryEquivalent_nonUnital

Shows why allowing nonunital input representations does not enlarge the irreducible representation class of the shell-generated algebra.

Level 3Focus target

Closed-ideal simplicity of the shell-generated algebra

MathlibAnnex.CStarAlgebra.CAR.isSimpleCStarAlgebra_shellFamilyTarget

Uses a faithful irreducible representation in the unique unitary-equivalence class to rule out proper nonzero closed two-sided ideals.

Level 4

Level 4Focus target

Structural properties of one shell-generated C*-algebra

MathlibAnnex.CStarAlgebra.CAR.shellFamilyEndpoint

Collects the proved properties of a single generated algebra, keeping the shell-family input separate from its consequences.

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