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Research draft

Gaussian integer

vr.tr.gaussian-integer · XCT.QTY

Let an agent explain Gaussian integers by definition, arithmetic, primes and applications in number theory.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain Gaussian integers by definition, arithmetic, primes and applications in number theory.

A complex number a + bi in which a and b are integers, forming the ring Z[i] of Gaussian integers, which has unique factorisation; Gaussian primes include 1 + i and ordinary primes congruent to 3 modulo 4, while primes congruent to 1 modulo 4 split, a fact linked to Fermat theorem on sums of two squares.

What it is for: Number theory and algebra.

It can be add, multiply and divide Gaussian integers; identify Gaussian primes; use the norm and Euclidean algorithm; connect to sums of two squares.

Distinguishing features

Integer real and imaginary parts

Forms a Euclidean domain

Unique factorisation

Norm a squared plus b squared

What it looks like

Not physical; points on the integer lattice of the complex plane.

How it is recognised

Numbers like 3 + 2i

Integer lattice points

Gaussian rationals allow fractions

Related models

is a kind of - category

quadratic integer

is part of - field

Gaussian rationals

is related to - number theory

square-free integer

is studied in - field

algebraic number theory

In practice

Families and kinds

Gaussian primes

units 1, -1, i and -i

associates

Gaussian integer lattice

Identifiers

Ring notation Z[i] ring of Gaussian integers

Standards and regulation

No specific regulation

Failure modes and hazards

Forgetting units when factorising

Confusing ordinary and Gaussian primes

Also called

Gaussian prime

Where this came from

wikidata · CC0 1.0

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Arithmetic Operations.

Rules extend integers.

Operate

Add and multiply.

Operate

Operations.

  1. What is the product or quotient of these Gaussian integers? measurement
  2. Is the division exact? boundary

Norm

Norm.

Norm

Norm.

  1. What is the norm of this Gaussian integer? measurement
  2. How is the norm used in division with remainder? definition
Primes Gaussian primes.

Primes behave differently.

Test

Primality.

Test

Gaussian primality.

  1. Is this Gaussian integer prime? boundary
  2. What is its factorisation up to units? measurement

Split

Ordinary primes.

Split

Splitting of primes.

  1. How does an ordinary prime factor in Z[i], depending on its remainder mod 4? definition
  2. Why does 2 ramify? definition
Applications Uses.

Gaussian integers solve problems.

Squares

Sums of two squares.

Squares

Sums of two squares.

  1. How do Gaussian integers show which numbers are sums of two squares? definition
  2. Which theorem is involved? provenance

Euclid

Euclidean algorithm.

Euclid

Euclidean algorithm.

  1. How does the Euclidean algorithm find a greatest common divisor in Z[i]? action
  2. Why is Z[i] a Euclidean domain? definition
Learning Teaching.

Pictures help.

Visual

Lattice pictures.

Visual

Visualisation.

  1. How can Gaussian primes be visualised in the complex plane? action
  2. Which symmetries appear? definition

History

Gauss.

History

History.

  1. How did Gauss introduce these numbers, according to historians of mathematics? provenance
  2. What problem motivated them? provenance

What the second pass must settle

  • Should Gaussian primes be a separate entry?
  • How should other quadratic integer rings be linked?
  • How should visualisations be linked?