Liouville numbers

E637310

Liouville numbers are real numbers that can be approximated extremely closely by rationals, making them a classic example of transcendental numbers in number theory.

All labels observed (4)

Label Occurrences
Liouville numbers canonical 3
Liouville 1
Liouville constant 0.1100010000000000000000010000... 1

How this entity was disambiguated

Statements (47)

Predicate Object
instanceOf Liouville number ⓘ
real number ⓘ
transcendental number ⓘ
approximationProperty approximable by rationals faster than any power of denominator ⓘ
belongsTo uncountable dense subset of R with measure zero ⓘ
cardinality uncountable ⓘ
characterizedBy can be approximated extremely closely by rational numbers ⓘ
closureProperty product of a nonzero rational number and a Liouville number is a Liouville number ⓘ
set of Liouville numbers is closed under addition with rationals ⓘ
set of Liouville numbers is closed under multiplication by nonzero rationals ⓘ
sum of a Liouville number and a rational number is a Liouville number ⓘ
complexExtension can be considered as complex numbers with zero imaginary part ⓘ
contrastWith algebraic irrational numbers ⓘ
badly approximable numbers ⓘ
normal numbers ⓘ
definedAs sum from k=1 to infinity of 10^{-k!} ⓘ
definition a real number x is a Liouville number if for every positive integer n there exist integers p and q>1 such that 0 < |x - p/q| < 1/q^n ⓘ
densityProperty between any two real numbers there exists a Liouville number ⓘ
disjointFrom algebraic numbers ⓘ
example Liouville constant 0.1100010000000000000000010000... ⓘ
linked to: Liouville numbers
field number theory ⓘ
firstUse to prove existence of transcendental numbers ⓘ
hasIrrationalityMeasure infinite ⓘ
historicalSignificance provided first explicit examples of transcendental numbers ⓘ
introducedBy Joseph Liouville ⓘ
introducedInYear 1844 ⓘ
logicalStatus proper subset of transcendental numbers ⓘ
measure Lebesgue measure zero ⓘ
namedAfter Joseph Liouville ⓘ
notClosedUnder addition of two Liouville numbers in general ⓘ
multiplication of two Liouville numbers in general ⓘ
property every Liouville number is transcendental ⓘ
every algebraic irrational has finite irrationality measure ⓘ
not every transcendental number is a Liouville number ⓘ
set of Liouville numbers is a dense G-delta set in R ⓘ
set of Liouville numbers is of first Baire category ⓘ
set of Liouville numbers is uncountable but meagre ⓘ
relatedTo Diophantine approximation ⓘ
irrationality measure ⓘ
researchArea metric Diophantine approximation ⓘ
transcendental number theory ⓘ
subsetOf real numbers ⓘ
transcendental numbers ⓘ
symbolicNotation often denoted by L in examples ⓘ
topologicalCategory F-sigma-delta set in R ⓘ
topologicalProperty dense in the real numbers ⓘ
usedIn construction of explicit transcendental numbers ⓘ

How these facts were elicited

Referenced by (6)

Full triples — surface form annotated when it differs from this entity's canonical label.

Diophantine approximation → hasKeyConcept → Liouville numbers ⓘ
Joseph Liouville → familyName → Liouville ⓘ
linked to: Liouville numbers
Joseph Liouville → hasEponym → Liouville number ⓘ
linked to: Liouville numbers
Roth's theorem → contrastsWith → Liouville numbers ⓘ
subject linked to: Roth theorem
Liouville number → example → Liouville constant 0.1100010000000000000000010000... ⓘ
subject linked to: Liouville numbers
linked to: Liouville numbers