Alphabeta Math
DefinitionDefinition: Literature-sourcedProof: Not applicableSession-authored (Fable 5 assisted)audited 2026-08-11
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For n1n\ge1, the determinant over a commutative ring by the Leibniz formula, and detA|\det A| for a real matrix

Definition

Let RR be a commutative ring, let n1n\ge1, and let A=(aij)Mn(R)A=(a_{ij})\in M_n(R). Its determinant is det(A):=σSnsgn(σ)i<naσ(i),i.\det(A):=\sum_{\sigma\in S_n}\operatorname{sgn}(\sigma)\prod_{i<n}a_{\sigma(i),i}. The sum is finite because SnS_n has n!n! elements. The product is taken in RR, so the signs 11 and 1-1 act through the ring identities. The formula uses columns indexed by i<ni<n and rows indexed by σ(i)\sigma(i).

When AA is real, detA|\det A| means the ordinary real absolute value of its real determinant. It is not alternate notation for the determinant itself.

Depends on

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Dependency tree · next 3 levels

Direct dependencies and their dependencies through the next three levels: 108 results over 27 levels. An arrow runs from a result to what uses it, and this result sits at the bottom with a heavier outline. Click the chart to enlarge it.

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