Skip to content

AlgebraicOrder ​

The order Z[a]\mathbb{Z}[a] generated by the algebraic integer aa: the polynomials in aa over Z\mathbb{Z}, a subring of finite index in the ring of integers of Q(a)\mathbb{Q}(a).

AlgebraicOrder(a)Z[a]\mathbb{Z}[a], for aa an algebraic integer; in degree 2 it is the QuadraticOrder of its discriminant (or QuadraticIntegers(d) when it is the whole ring)
Typed signatures
TypePackageApplies
(number) -> set<number>number-theoryalways

Domain: Number theory

Details
  • Named by a generator because past degree 2 orders aren't determined by their discriminant; its index in AlgebraicIntegers is disc Z[a]/dK\sqrt{\mathrm{disc}\,\mathbb{Z}[a] / d_K}
  • A value for Over, as AlgebraicIntegers is; at a prime dividing the index, O/(x)\mathcal{O}/(x) being a field is still what makes (x)(x) prime

Examples

Basic #

Z[−3]\mathbb{Z}[\sqrt{-3}], of conductor 2

live ↗
InAlgebraicOrder(−3)\mathrm{AlgebraicOrder}(\sqrt{-3})OutQuadraticOrder(−12)\mathrm{QuadraticOrder}(-12)

Z[23]\mathbb{Z}[\sqrt[3]{2}] is all of OK\mathcal{O}_K, but keeps its name

live ↗
InAlgebraicOrder(23)\mathrm{AlgebraicOrder}(\sqrt[3]{2})OutAlgebraicOrder(23)\mathrm{AlgebraicOrder}(\sqrt[3]{2})

3 does not divide the index 2, so it is prime in Z[θ]\mathbb{Z}[\theta] as in OK\mathcal{O}_K

live ↗
InIsPrime(3,KeyValuePair⁡(Over,AlgebraicOrder(PolynomialRoot(x3−x2−2x−8,1))))\mathrm{IsPrime}(3, \operatorname{KeyValuePair}(\mathrm{Over}, \mathrm{AlgebraicOrder}(\mathrm{PolynomialRoot}(x^3-x^2-2x-8, 1))))OutTrue\mathrm{True}
About
Examples3
CrosswalkSageMath

Implementation

mappedwolframpackages/oracle/src/mappings.ts

Wolfram has no orders besides the maximal one.

See also: AlgebraicIntegers, QuadraticOrder, MinimalPolynomial