Khintchine theorem

E637305

Khintchine theorem is a fundamental result in metric Diophantine approximation that characterizes, via a simple convergence–divergence criterion, when almost all real numbers admit infinitely many rational approximations of a prescribed quality.

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Statements (38)

Predicate Object
instanceOf mathematical theorem
result in metric Diophantine approximation
alternativeName Khinchin theorem
linked to: Khintchine theorem
appliesTo simultaneous approximation in higher dimensions via extensions
areaOfInfluence fractal geometry of Diophantine sets
probabilistic number theory
assumes monotone approximating function in its classical form
characterizes when almost all real numbers admit infinitely many rational approximations of prescribed quality
concerns Lebesgue measure of sets of well-approximable numbers
approximation of real numbers by rationals
metric Diophantine approximation
criterionType convergence–divergence criterion
domain real numbers
field Diophantine approximation
number theory
generalizationOf Borel–Cantelli lemma applications in Diophantine approximation
givesCriterionFor existence of infinitely many good rational approximations for almost all real numbers
hasConsequence for almost all real numbers the quality of rational approximation is governed by a simple series test
historicalPeriod 20th century mathematics
implies if a certain series converges then the corresponding limsup set has Lebesgue measure zero
if a certain series diverges then the corresponding limsup set has full Lebesgue measure
mathematicalSubjectClassification 11J83
11K60
namedAfter Aleksandr Yakovlevich Khinchin
linked to: Aleksandr Khinchin
quantifier almost all real numbers
relatedTo Borel–Cantelli lemma
Duffin–Schaeffer conjecture
linked to: Khintchine theorem

Jarník–Besicovitch theorem
Khintchine–Groshev theorem
relates sum of q times approximating function to measure of well-approximable numbers
statementForm zero–one law for Lebesgue measure
usedIn metric theory of Diophantine approximation
study of well-approximable numbers
usesConcept Lebesgue measure
approximating function
convergence of series
divergence of series
limsup set

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Referenced by (7)

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

Diophantine approximation hasKeyResult Khintchine theorem
Diophantine approximation hasKeyResult Khintchine–Groshev theorem
linked to: Khintchine theorem
Khinchin's constant appearsIn Khinchin's theorem on continued fractions
linked to: Khintchine theorem
Hurwitz theorem hasGeneralization Khinchin-type theorems in Diophantine approximation
linked to: Khintchine theorem
Khintchine theorem alternativeName Khinchin theorem
linked to: Khintchine theorem
Khintchine theorem relatedTo Duffin–Schaeffer conjecture
linked to: Khintchine theorem
Jarník–Besicovitch theorem relatedTo Khintchine theorem