Primitive ideal
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In mathematics, specifically ring theory, a left primitive ideal is the annihilator of a (nonzero) simple left module. A right primitive ideal is defined similarly. Left and right primitive ideals are always two-sided ideals.
Primitive ideals are prime. The quotient of a ring by a left primitive ideal is a left primitive ring. For commutative rings the primitive ideals are maximal, and so commutative primitive rings are all fields.
Contents
• See also
• Notes
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Primitive spectrum
The primitive spectrum of a ring is a non-commutative analogcite-ref-1[note 1] of the prime spectrum of a commutative ring.
Let A be a ring and Prim ( A ) {\displaystyle \operatorname {Prim} (A)} the set of all primitive ideals of A. Then there is a topology on Prim ( A ) {\displaystyle \operatorname {Prim} (A)} , called the Jacobson topology, defined so that the closure of a subset T is the set of primitive ideals of A containing the intersection of elements of T.
Now, suppose A is an associative algebra over a field. Then, by definition, a primitive ideal is the kernel of an irreducible representation π π {\displaystyle \pi } of A and thus there is a surjection
π π ↦ ↦ ker π π : A ^ ^ → → Prim ( A ) . {\displaystyle \pi \mapsto \ker \pi :{\widehat {A}}\to \operatorname {Prim} (A).}
Example: the spectrum of a unital C*-algebra.
See also
Notes
cite-note-1note 1. ↑ A primitive ideal tends to be more of interest than a prime ideal in non-commutative ring theory.
References
• citerefdixmier1996Dixmier, Jacques (1996) [1974], Enveloping algebras, Graduate Studies in Mathematics, vol. 11, Providence, R.I.: American Mathematical Society, ISBN 978-0-8218-0560-2, MR 0498740
• citerefisaacs1994Isaacs, I. Martin (1994), Algebra, Brooks/Cole Publishing Company, ISBN 0-534-19002-2
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