A proper ideal m of a commutative ring R is maximal when no proper ideal lies strictly between m and R. Equivalently, R/m is a field.
The residue field at a maximal ideal m is the quotient field κ(m)=R/m. At a prime ideal p, the residue field is the fraction field of R/p.
A local homomorphism of local rings (R,m)→(S,n) induces the residue-field extension R/m→S/n. For an extension of non-Archimedean local fields, its degree is the residue-field degree.
The residue characteristic of a local ring is the characteristic of a ring of its residue field. A finite extension of Qp has residue characteristic p.
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- Algebraic cotangent space
- Artinian commutative ring is Noetherian theorem
- Closed point
- Closed-point dimension lemma for affine domains
- Conormal module
- Discrete valuation from nontrivial local compactness
- Embedding dimension
- Existence of minimal primes over a proper ideal
- Initial-form lower bound for ideal generators
- Integral closure as an intersection of valuation rings
- Localization detects zero elements
- Local parameter on a smooth algebraic curve
- Minimal primes are associated primes
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- Prime ideals of a commutative Artinian ring
- Prime-to-residue-characteristic multiplication on a formal group
- Radical equality for finitely generated integer algebras
- Real affine plane scheme points
- Regular local ring
- Surjectivity of good reduction over a local field
- Unavoidable support at a non-Cartier point
- Uniformizer
- Valuation domination lemma
- Valuation rings are integrally closed
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In abstract algebra, a **maximal ideal** is a specific type of ideal within a ring. To define it, let's first recall some basic concepts related to rings and ideals: 1. **Ring**: A set equipped with two binary operations, typically called addition and multiplication, satisfying certain properties (like associativity, distributivity, etc.). 2. **Ideal**: A subset of a ring that absorbs multiplication by elements from the ring and is closed under addition.