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.
Whitney sum, tensor, dual, Hom, and exterior-power bundles
Definition
Let and be finite-rank -vector bundles over , with transition matrices and on a common refinement. Apply Vector bundles are glued from transition cocycles to the following transition maps:
- : ;
- : ;
- : ;
- : ;
- : .
These define the Whitney sum, tensor product, dual, Hom, and exterior-power bundles. Their fibers are respectively , , , , and . The cocycle theorem also shows that changes of frame give canonically isomorphic bundles.
For a complex bundle, conjugating every transition matrix defines , and regarding those matrices as real-linear defines the underlying real bundle . We set and when . Applying the same matrices after precomposition with a base map shows, under the canonical comparisons of Vector-bundle pullback is canonically functorial, that every construction commutes with pullback.
Depends on
Used by
- Integral total Pontryagin multiplicativity cannot ignore two-torsion Counterexample
- Stable isomorphism does not imply actual bundle isomorphism Counterexample
- Complex flag bundle and Chern roots Definition
- Grothendieck ring structure and rank map Definition
- Pontryagin classes by complexification Definition
- Real flag bundle and Stiefel–Whitney roots Definition
- The Whitney-sum monoid of complex vector bundles Definition
- Chern classes of a sum of universal complex lines Example
- Stability and rank cutoff under adding a trivial summand Example
- Stiefel-Whitney numbers of real projective space Example
- Integral powers of the complexified universal real line Lemma
- Polynomial clutching families stabilize to linear clutching Lemma
- Stiefel-Whitney classes of the tangent bundle of real projective space Lemma
- The boundary stable tangent bundle splits off a trivial line Lemma
- The complex orientation of the underlying real bundle Lemma
- The complexified tautological line resolves real-projective K-theory extensions Lemma
- The tangent bundle of complex projective space and its Pontryagin classes Lemma
- Complexification is conjugation invariant Proposition
- Direct-sum and pullback formulas for characteristic forms Proposition
- First Chern class of tensor, dual, and conjugate lines Proposition
- The first Stiefel–Whitney class classifies orientability Proposition
- Chern character is a natural ring homomorphism on K-zero Theorem
- External-product and Whitney-sum formulas for Thom classes Theorem
- Mod-two reduction of Chern classes Theorem
- Naturality, normalization, and Whitney sum for Chern classes Theorem
- Naturality, orientation sign, and Whitney product for Euler classes Theorem
- Naturality, stability, and mod-two reduction of Pontryagin classes Theorem
- Pontryagin Whitney product away from two Theorem
- Real splitting principle with mod-two injective pullback Theorem
- The first Chern class classifies complex line bundles Theorem
- Top Pontryagin class is the square of the Euler class Theorem
- Whitney sum formula for Stiefel–Whitney classes Theorem
Dependency tree · two levels
5 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
- Hatcher, Vector Bundles & K-Theory, §1.1 (standard reference, not scraped)
- Milnor and Stasheff, Characteristic Classes, §3 (standard reference, not scraped)