Dominated Convergence Theorem: Difference between revisions

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==Statement and proof of Theorem==
==Statement and proof of Theorem==
====Statement====  
====Statement====  
Suppose <math>\{f_n\}</math> is a sequence of [[Measurable function | measurable functions]] such that <math>f_n(x) \to f(x)</math> a.e. x, as n goes to infinity. If <math>|f_n(x)|\leq g(x) </math>, where g is integrable, then
Suppose <math>\{f_n\}</math> is a sequence of [[Measurable function | measurable functions]] such that <math>f_n(x) \to f(x)</math> a.e. x, as n goes to infinity. If <math>|f_n(x)|\leq g(x) </math>, where g is integrable, then <math>f \in \mathrb{L^1}</math> and  
:<math>\int |f_n-f|\to 0</math>
and consequently
:<math>\int f_n \to \int f</math>
:<math>\int f_n \to \int f</math>

Revision as of 04:09, 18 December 2020

In measure theory, the dominated convergence theorem is a cornerstone of Lebesgue integration. It can be viewed as a culmination of all efforts, and is a general statement about the interplay between limits and integrals.

Statement and proof of Theorem

Statement

Suppose is a sequence of measurable functions such that a.e. x, as n goes to infinity. If , where g is integrable, then Failed to parse (unknown function "\mathrb"): {\displaystyle f \in \mathrb{L^1}} and