Gaussian integers

E29369

Gaussian integers are complex numbers whose real and imaginary parts are both integers, forming a lattice in the complex plane with important applications in number theory and algebra.


Statements (60)
Predicate Object
instanceOf Euclidean domain
integral domain
lattice in the complex plane
mathematical object
principal ideal domain
ring
unique factorization domain
associatedWith Fermat's sum of two squares theorem
characterizes odd prime p is sum of two squares iff p is not prime in ℤ[i]
closedUnder addition
multiplication
subtraction
contains all numbers of the form a+0i with a in ℤ
ordinary integers
definedAs complex numbers of the form a+bi where a and b are integers
distanceMetric induced by complex absolute value
EuclideanFunction norm
fieldOfFractions Gaussian rationals ℚ(i)
forms two-dimensional lattice over ℤ
geometricStructure square lattice in the complex plane
hasAdditiveGroupIsomorphicTo ℤ²
hasClassNumber 1
hasElementForm a+bi with a,b in ℤ and i² = -1
hasKrullDimension 1
hasNormFunction N(a+bi) = a² + b²
hasPrimeElement 1+i
1-i
2
2+i
2-i
3+2i
3-2i
5
hasUnit -1
-i
1
i
hasZeroDivisors false
isCommutativeRingWithIdentity true
isDedekindDomain true
isIntegrallyClosed true
isNoetherianRing true
isRingOfIntegersOf quadratic field ℚ(i)
maximalIdealsCorrespondTo Gaussian primes
normIs multiplicative
normTakesValuesIn nonnegative integers
notClosedUnder division
numberOfUnits 4
primeFactorization every nonzero nonunit factors uniquely up to units and order
primeInGaussianIntegersCondition odd prime p ≡ 3 (mod 4) remains prime in ℤ[i]
primeSplittingProperty odd prime p ≡ 1 (mod 4) factors as π·π̄ in ℤ[i]
ramifiedPrime 2 = (1+i)² up to units
subsetOf complex numbers

symbol ℤ[i]
unitsFormGroupIsomorphicTo cyclic group of order 4
usedIn algebraic geometry over ℤ[i]
algebraic number theory
lattice-based constructions in geometry of numbers
proofs of representation of primes as sums of two squares

Referenced by (2)
Subject (surface form when different) Predicate
Carl Friedrich Gauss
hasConceptNamedAfter
Ulam spiral
relatedConcept

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