Whitney sum

E285917

The Whitney sum is a construction in differential topology that combines two vector bundles over the same base space into a new vector bundle whose fibers are direct sums of the original fibers.

All labels observed (3)

How this entity was disambiguated

Statements (48)

Predicate Object
instanceOf operation on vector bundles ⓘ
vector bundle construction ⓘ
alsoKnownAs Whitney sum of vector bundles ⓘ
linked to: Whitney sum

direct sum of vector bundles ⓘ
appearsIn construction of stable normal bundles ⓘ
splitting of exact sequences of vector bundles ⓘ
theory of tangent and normal bundles ⓘ
appliesTo complex vector bundles ⓘ
real vector bundles ⓘ
topological vector bundles ⓘ
baseSpacePreserved true ⓘ
compatibility compatible with pullback along continuous or smooth maps ⓘ
compatible with restriction of bundles to subspaces ⓘ
definedOn vector bundles over the same base space ⓘ
definesOperationOn isomorphism classes of vector bundles over a fixed base ⓘ
fiberwiseDescription (E ⊕ F)_x = E_x ⊕ F_x for each x in B ⓘ
field algebraic topology ⓘ
differential topology ⓘ
geometry ⓘ
generalizes direct sum of vector spaces ⓘ
givesMonoidStructureTo set of isomorphism classes of vector bundles over a base space ⓘ
hasIdentityElement zero vector bundle ⓘ
hasInput vector bundle E → B ⓘ
vector bundle F → B ⓘ
hasLocalDescription given local trivializations, transition functions are block-diagonal sums ⓘ
hasOutput vector bundle E ⊕ F → B ⓘ
isAssociativeUpToIsomorphism true ⓘ
isCommutativeUpToIsomorphism true ⓘ
isFunctorial true ⓘ
namedAfter Hassler Whitney ⓘ
preservesComplexStructure true ⓘ
preservesSmoothStructure true ⓘ
relatedConcept external direct sum of bundles ⓘ
pullback of vector bundles ⓘ
tensor product of vector bundles ⓘ
requiresCondition bundles are of the same category (e.g. smooth, topological, complex) ⓘ
bundles share the same base space ⓘ
satisfiesProperty c(E ⊕ F) = c(E) ∪ c(F) for total Chern classes ⓘ
p(E ⊕ F) = p(E) ∪ p(F) for Pontryagin classes ⓘ
rank(E ⊕ F) = rank(E) + rank(F) ⓘ
w(E ⊕ F) = w(E) ∪ w(F) for Stiefel–Whitney classes ⓘ
symbol ⊕ ⓘ
⨁ ⓘ
usedIn classification of vector bundles ⓘ
construction of characteristic classes ⓘ
construction of topological K-groups ⓘ
definition of K-theory ⓘ
stable equivalence of vector bundles ⓘ

How these facts were elicited

Referenced by (4)

Full triples — surface form annotated when it differs from this entity's canonical label.

Whitney sum → alsoKnownAs → Whitney sum of vector bundles ⓘ
linked to: Whitney sum
Pontryagin classes → satisfies → Whitney sum formula ⓘ
linked to: Whitney sum
Stiefel–Whitney classes → axiomatizedBy → Whitney sum formula ⓘ
linked to: Whitney sum