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.
Killing form
Definition
For a finite-dimensional Lie algebra , its Killing form is the trace form of the adjoint representation:
Here . Thus the trace is taken on the vector space itself. In particular, if or if is abelian, then every adjoint operator is zero and . Symmetry and invariance will follow from the general trace-form calculation rather than being included in the definition.
Depends on
Used by
- Maximal compact subgroups exist and are conjugate in a connected finite center semisimple Lie group Corollary
- Semisimple Lie algebras are centerless and perfect Corollary
- Same complexification with different killing form signatures Counterexample
- Cartan involution of a real semisimple Lie algebra Definition
- Cayley transform of a theta-stable Cartan subalgebra Definition
- Compact real form of a complex semisimple Lie algebra Definition
- Dual Coxeter number for the normalized invariant form Definition
- Killing-dual vector of a root Definition
- A nonreduced bc root system from a real form Example
- A reductive algebra with degenerate Killing form Example
- Cartan involution and k plus p for sl n r Example
- Cartan subalgebra and roots of sl₂ Example
- Classical simple Lie algebras and their Killing forms Example
- Compact and split real forms of sl two c Example
- Complex simple lie algebra viewed as a real simple algebra Example
- Hyperbolic space as so zero n one mod so n Example
- Killing form of sl₂ Example
- Standard and dual representations of slₙ Example
- The Killing form identifies roots with coroot directions Example
- The root sl₂ triple inside slₙ Example
- A plain dynkin diagram classifies real forms False statement
- All real forms of a complex semisimple lie algebra are isomorphic False statement
- Dynkin diagrams classify real semisimple Lie algebras False statement
- The Killing form is nondegenerate on every reductive Lie algebra False statement
- Chevalley basis and real structure constants Lemma
- The Killing length of a root is nonzero Lemma
- Bracket relations and Killing signs in a Cartan decomposition Proposition
- Cartan decomposition gives the invariant metric and curvature of G mod K Proposition
- Complexification preserves semisimplicity Proposition
- Orthogonality of root spaces and nondegeneracy on the Cartan subalgebra Proposition
- Real Cartan subalgebras need not be conjugate Proposition
- The bracket of opposite root spaces is the root line Proposition
- The roots form a reduced crystallographic Euclidean root system Proposition
- Cartan subalgebras are exactly maximal toral subalgebras Theorem
- Cartan's solvability criterion Theorem
- Compact roots form a reduced crystallographic root system Theorem
- Conjugacy of Cartan involutions Theorem
- Conjugacy of Cartan subalgebras Theorem
- Conjugacy of compact real forms Theorem
- Every real Cartan subalgebra is conjugate to a theta-stable one Theorem
…and 9 more results.
Dependency tree · two levels
7 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
- Milne, Lie Algebras, §4, Killing form (standard reference, not scraped)