Math 2.0

statement corollary

Maximal ideals are prime

Statement

Let RR be a commutative ring and let MM be a maximal ideal of RR. Then MM is a prime ideal.

Remarks

The proof: R/MR/M is a field, so it is an integral domain, so MM is prime. The converse is false: the zero ideal of Z\mathbb{Z} is prime but not maximal. In Z\mathbb{Z}, every nonzero prime ideal is maximal.

Explanations

L1 human

Every field is an integral domain. So when R/MR/M is a field, R/MR/M is an integral domain, and MM is prime. The zero ideal of the integers shows that a prime ideal need not be maximal.

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To read this node, read these 17 nodes in this order. The foundations come first, and the list ends with this node.

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  1. Group concept
  2. Ring definition
  3. Commutative ring definition
  4. Ideal definition
  5. Unit of a ring definition
  6. Zero divisor definition
  7. Prime ideal definition
  8. Field definition
  9. Maximal ideal definition
  10. Two-sided ideal definition
  11. Integral domain definition
  12. The only ideals of a field are zero and the whole field statement
  13. Quotient ring definition
  14. Correspondence theorem for rings statement
  15. R/P is an integral domain iff P is prime statement
  16. R/M is a field iff M is maximal statement
  17. Maximal ideals are prime statement

Sources

  1. Web https://en.wikipedia.org/wiki/Maximal_ideal, Properties