MATHLIBANNEX / PROJECT LFH

Pure states and faithfulness

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Scope

A pure state detects a hypothetical nonzero kernel element and its GNS representation is irreducible. Unitary equivalence to the singleton representative then contradicts that kernel element, giving faithfulness and the related simplicity consequence.

5 direct Cards + 5 reused prerequisites = 10 unique Cards. This count is a selected Card closure, not a source-declaration count.

Route reading PDF · Preserved source exploration

Cards in this route

Read this route with prerequisites

Reference index: direct Cards and reused prerequisites

Direct references: R08 — Pure states as real extreme points · R20 — The GNS representation of a pure state is irreducible · R07 — A pure state detects a nonzero square · R12 — Faithfulness from a unique irreducible class · R03 — A faithful singleton model forces simplicity

Reused prerequisites: R05 — A representative of the unique irreducible class · R24 — Nonzero irreducibility without a unit assumption · R25 — Unitary equivalence of two representations · R30 — A character extends to a pure state · R32 — Representations without a unit-preservation requirement

Dependency-first reading route

Read selected Card prerequisites before their uses. Levels are recomputed from the selected reachability-preserving projection; omitted source helpers remain traceable in the source exploration.

10 Cards

Level 0 (2 Cards)

Level 1 (4 Cards)

Level 2 (3 Cards)

Level 2

A representative of the unique irreducible class

Defines when one nonzero irreducible -representation represents the sole unitary-equivalence class of such representations.

MathlibAnnex.Analysis.CStarAlgebra.NonUnitalCStarRepresentation.IsSingletonIrreducibleModel

Level 3 (1 Card)

Level 3

Faithfulness from a unique irreducible class

Uses a pure state on the unitization to detect any hypothetical nonzero element of the kernel.

MathlibAnnex.Analysis.CStarAlgebra.NonUnitalCStarRepresentation.injective_of_singleton