Hurwitz theorem (composition algebras)

E931272

Hurwitz theorem (composition algebras) is a fundamental result in algebra that classifies all finite-dimensional normed division algebras over the real numbers, showing that they exist only in dimensions 1, 2, 4, and 8.

All labels observed (3)

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Statements (47)

Predicate Object
instanceOf mathematical theorem ⓘ
result in normed division algebras ⓘ
theorem in algebra ⓘ
allowsDimensions 1 ⓘ
2 ⓘ
4 ⓘ
8 ⓘ
characterizes C as the unique 2-dimensional real normed division algebra up to isomorphism ⓘ
H as the unique 4-dimensional real normed division algebra up to isomorphism ⓘ
O as the unique 8-dimensional real normed division algebra up to isomorphism ⓘ
R as the unique 1-dimensional real normed division algebra ⓘ
classifies finite-dimensional real normed division algebras ⓘ
real composition algebras with multiplicative norm ⓘ
concerns composition algebra ⓘ
multiplicative norm ⓘ
normed division algebra ⓘ
quadratic form ⓘ
real numbers ⓘ
describes possible dimensions of composition algebras over the reals ⓘ
structure of real normed division algebras ⓘ
equivalentTo classification of real composition algebras with nondegenerate multiplicative quadratic form ⓘ
field algebra ⓘ
number theory ⓘ
topology ⓘ
forbidsDimensions any other positive integer dimension than 1, 2, 4, or 8 for real normed division algebras ⓘ
hasConsequence existence of normed bilinear maps R^n × R^n → R^n only for n = 1, 2, 4, 8 ⓘ
restriction on possible dimensions of parallelizable spheres ⓘ
hasVariant Hurwitz theorem on composition of quadratic forms ⓘ
historicalPeriod late 19th century ⓘ
implies every finite-dimensional real normed division algebra is isomorphic to R, C, H, or O as a normed algebra ⓘ
there are no real normed division algebras of dimension 3 ⓘ
there are no real normed division algebras of dimension 5 ⓘ
there are no real normed division algebras of dimension 6 ⓘ
there are no real normed division algebras of dimension 7 ⓘ
there are no real normed division algebras of dimension greater than 8 ⓘ
impliesExistenceOf only four isomorphism classes of real normed division algebras ⓘ
namedAfter Adolf Hurwitz ⓘ
provedBy Adolf Hurwitz ⓘ
relatedTo complex numbers C ⓘ
octonions O ⓘ
quaternions H ⓘ
real numbers R ⓘ
statement every finite-dimensional real normed division algebra has dimension 1, 2, 4, or 8 ⓘ
the only finite-dimensional real composition algebras with a positive-definite multiplicative norm have dimensions 1, 2, 4, or 8 ⓘ
usesConcept bilinear form ⓘ
composition of quadratic forms ⓘ
quadratic form identity ⓘ

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Referenced by (4)

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

Adolf Hurwitz → knownFor → Hurwitz theorem (composition algebras) ⓘ
Adolf Hurwitz → notableWork → Hurwitz theorem (composition algebras) ⓘ
subject linked to: Hurwitz
Rouché's theorem → relatedTo → Hurwitz's theorem ⓘ
linked to: Hurwitz theorem (composition algebras)
Hurwitz theorem (composition algebras) → hasVariant → Hurwitz theorem on composition of quadratic forms ⓘ
linked to: Hurwitz theorem (composition algebras)