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Linear Disjointness

In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met.

Version
v1 · 2026-09-28 · History
Domain-specific #
10413
Domain group
Formal Sciences
Origin domain
Mathematics
Subdomains
Field Theory, Commutative Algebra → Mathematics

Core Idea

Linear Disjointness is treated here as the recurring field theory identity summarized by this source-grounded definition: In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met. In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met. (i) The map A \otimesk B \to AB induced by (x, y) \mapsto xy is injective.

Scope of Application

  • Documented setting. However, there are examples where A \otimesk B is a domain but A and B are not linearly disjoint: for example, A = B = k(t), the field of rational functions over.

  • Documented setting. In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met.

  • Documented setting. (i) The map A \otimesk B \to AB induced by (x, y) \mapsto xy is injective.

  • Documented setting. (iii) There exists a k-basis of A which remains linearly independent over B.

  • Documented setting. (iv) If ui, vj are k-bases for A, B, then the products ui vj are linearly independent over k.

Clarity

A clear use of Linear Disjointness names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met.

Manages Complexity

Linear Disjointness compresses multiple field theory details into a stable diagnostic relation. The source shows both the central mechanism—one also has: A, B are linearly disjoint over k if and only if the subfields of \Omega generated by A, B , resp. are linearly disjoint over k.—and the practical consequence—note that, since every subalgebra of \Omega is a domain, (i) implies A \otimesk B is a domain (in.

Abstract Reasoning

  1. Type the carrier. Identify the field theory entities to which the claim applies.
  2. State the relation. Use the source-grounded identity: In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met.
  3. Check operation and conditions. In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are.

Knowledge Transfer

Within the home domain. Knowledge about Linear Disjointness transfers literally when a new case preserves the same carrier type, relation, and recognition test. However, there are examples where A \otimesk B is a domain but A and B are not linearly disjoint: for example, A = B = k(t), the field of rational functions over k. In mathematics, algebras A, B over a field k inside some field extension \Omega of k are said to be linearly disjoint over k if the following equivalent conditions are met. Beyond the home domain. No canonical.

Relationships to Other Abstractions

Local relationship map for Linear DisjointnessParents appear above the current abstraction, mutual partners to the right, and children below. Node labels state whether each abstraction is prime or domain-specific; colors identify relation types.Linear DisjointnessDOMAINPrime abstraction: Disjointness — is a decomposition ofDisjointnessPRIME

Current abstraction Linear Disjointness Domain-specific

Parents (1) — more general patterns this builds on

  • Linear Disjointness is a decomposition of Disjointness Prime

    Linear disjointness is the field-theoretic framing of two embedded algebras sharing no unintended linear dependence.

Hierarchy path (1) — routes to 1 parentless root

Neighborhood in Abstraction Space

Linear Disjointness sits in a moderately populated region (49th percentile for distinctiveness): it has near-neighbors but no dense thicket of look-alikes.

Family — Algebraic Structures, Groups & Operators (42 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08