Commutative algebra | Ideals (ring theory) | Theorems in ring theory

Krull's principal ideal theorem

In commutative algebra, Krull's principal ideal theorem, named after Wolfgang Krull (1899–1971), gives a bound on the height of a principal ideal in a commutative Noetherian ring. The theorem is sometimes referred to by its German name, Krulls Hauptidealsatz (Satz meaning "proposition" or "theorem"). Precisely, if R is a Noetherian ring and I is a principal, proper ideal of R, then each minimal prime ideal over I has height at most one. This theorem can be generalized to ideals that are not principal, and the result is often called Krull's height theorem. This says that if R is a Noetherian ring and I is a proper ideal generated by n elements of R, then each minimal prime over I has height at most n. The converse is also true: if a prime ideal has height n, then it is a minimal prime ideal over an ideal generated by n elements. The principal ideal theorem and the generalization, the height theorem, both follow from the fundamental theorem of dimension theory in commutative algebra (see also below for the direct proofs). Bourbaki's Commutative Algebra gives a direct proof. Kaplansky's Commutative Rings includes a proof due to David Rees. (Wikipedia).

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Commutative algebra 59: Krull's principal ideal theorem

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From playlist Commutative algebra

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From playlist Abstract Algebra

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From playlist Commutative algebra

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From playlist Arithmetic and Algebraic Geometry: A conference in honor of Ofer Gabber on the occasion of his 60th birthday

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From playlist Introduction to Additive Combinatorics (Cambridge Part III course)

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From playlist Abstract Algebra

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From playlist Commutative algebra

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From playlist Commutative algebra

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From playlist The Legacy of Emmy Noether

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From playlist The Legacy of Emmy Noether

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From playlist Combinatorics

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From playlist Introduction to Additive Combinatorics (Cambridge Part III course)

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From playlist Introduction to Additive Combinatorics (Cambridge Part III course)

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From playlist Rings and modules

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From playlist Seminar on Applied Geometry and Algebra (SIAM SAGA)

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Notes by Keith Conrad to follow along: https://kconrad.math.uconn.edu/blurbs/linmultialg/modulesoverPID.pdf

From playlist Abstract Algebra 2

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From playlist Algebraic Calculus One

Related pages

Radical of an ideal | Commutative algebra | Minimal prime ideal | Ideal (ring theory) | Localization (commutative algebra) | Nakayama's lemma | Noetherian ring | Primary ideal | Principal ideal