Lebesgue decomposition theorem
E898510
The Lebesgue decomposition theorem is a fundamental result in measure theory that states any σ-finite measure can be uniquely decomposed into a part that is absolutely continuous with respect to another measure and a part that is singular to it.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Lebesgue decomposition theorem canonical | 1 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
result in mathematical analysis
ⓘ
theorem in measure theory ⓘ |
| appliesTo |
finite measures
ⓘ
positive measures ⓘ σ-finite measures ⓘ |
| assumes | σ-algebra of measurable sets ⓘ |
| characterizes |
part of a measure that is absolutely continuous with respect to ν
ⓘ
part of a measure that is concentrated on a ν-null set ⓘ |
| classification | fundamental decomposition theorem for measures ⓘ |
| context |
integration with respect to different measures
ⓘ
modern measure-theoretic foundations of probability ⓘ |
| describes | decomposition of a measure relative to another measure ⓘ |
| field | measure theory ⓘ |
| formalStatement | Given σ-finite measures μ and ν on a measurable space, there exist unique measures μ_ac and μ_s such that μ = μ_ac + μ_s, μ_ac ≪ ν, and μ_s ⟂ ν NERFINISHED ⓘ |
| generalizes | Lebesgue decomposition of distribution functions ⓘ |
| guarantees |
uniqueness of the absolutely continuous component
ⓘ
uniqueness of the singular component ⓘ |
| hasConsequence |
every measure can be split into continuous and singular parts relative to a reference measure
ⓘ
structure theorem for measures on a measurable space ⓘ |
| holdsOn | a common measurable space for μ and ν ⓘ |
| implies | existence of a Radon–Nikodym derivative dμ_ac/dν ⓘ |
| involvesConcept |
Radon–Nikodym derivative
NERFINISHED
ⓘ
absolute continuity of measures ⓘ measure decomposition ⓘ mutual singularity of measures ⓘ singular measures ⓘ |
| isToolFor |
analyzing relationships between two measures
ⓘ
describing singular components of distributions ⓘ disintegrating probability measures ⓘ |
| namedAfter | Henri Lebesgue NERFINISHED ⓘ |
| relatedTo |
Jordan decomposition theorem
NERFINISHED
ⓘ
Lebesgue–Stieltjes measures NERFINISHED ⓘ Lebesgue’s decomposition of measures into discrete and continuous parts NERFINISHED ⓘ Radon–Nikodym theorem NERFINISHED ⓘ |
| requires | σ-finiteness of the reference measure ⓘ |
| statesThat |
any σ-finite measure μ can be decomposed into μ_ac + μ_s relative to another σ-finite measure ν
ⓘ
the decomposition μ = μ_ac + μ_s is unique ⓘ μ_ac is absolutely continuous with respect to ν ⓘ μ_s is singular with respect to ν ⓘ |
| symbolicForm | μ = μ_ac + μ_s with μ_ac ≪ ν and μ_s ⟂ ν ⓘ |
| usedIn |
ergodic theory
ⓘ
functional analysis ⓘ harmonic analysis ⓘ probability theory ⓘ spectral theory ⓘ stochastic processes ⓘ |
| usesNotation |
μ ≪ ν for absolute continuity
ⓘ
μ ⟂ ν for mutual singularity ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.