Factbites
 Where results make sense
About us   |   Why use us?   |   Reviews   |   PR   |   Contact us  

Topic: Lebesgue


Related Topics

In the News (Sun 29 Nov 09)

  
  NationMaster - Encyclopedia: Lebesgue measure
Lebesgue measure is both locally finite and inner regular, and so it is a Radon measure.
The modern construction of the Lebesgue measure, based on outer measures, is due to Carathéodory.
Category: Measures (measure theory) In mathematics, Lebesgues density theorem states that for any Lebesgue measurable set A, the density of A is 1 at almost every point in A. Intuitively, this means that the edge of A, the set of points in A whose neighborhood is partially in A and partially outside of...
www.nationmaster.com /encyclopedia/Lebesgue-measure   (2320 words)

  
 An Introduction to the Gauge Integral
Lebesgue's definition is appreciably more complicated, but Lebesgue's techniques yield better convergence theorems and, for the most part, more integrable functions.
The integrals of Lebesgue, Denjoy, Perron, and Henstock by Russell Gordon, 1994.
Every introductory textbook on Lebesgue integrals includes a short proof (due to Vitali) of the existence of a nonmeasurable set; the characteristic function of that set is then a nonmeasurable function.
www.math.vanderbilt.edu /~schectex/ccc/gauge   (4371 words)

  
 Henri Lebesgue Summary
Lebesgue's theory, which was fundamentally a generalization of Riemann's integral theory, included a measure-theoretic viewpoint that made the Lebesgue integral, as it became known, useful in several branches of mathematics, such as curve rectification and the theory of trigonometric series.
Lebesgue inherited the solid foundation for the theory of calculus that was laid by the mathematical giants of the 19th century.
Although Lebesgue's integral was an example of the power of generalisation, Lebesgue himself did not approve of generalisation in general and spent the rest of his life working on very specific problems, generally in mathematical analysis.
www.bookrags.com /Henri_Lebesgue   (4504 words)

  
 PlanetMath: Henri Lebesgue
By the time he turned 30, Lebesgue was a published book author with a book on primitive functions and another one on the trigonometric series.
Lebesgue's saying that “Mathematics reduced to general theories would be a beautiful form without content” has found its way into many quotation dictionaries.
This is version 2 of Henri Lebesgue, born on 2007-02-06, modified 2007-02-06.
planetmath.org /encyclopedia/HenriLebesgue.html   (181 words)

  
 Lebesgue Measure
An introduction to the Lebesgue integral, Lebesgue measure, and convergence theorems, with application to function spaces such as the LP spaces.
A Lebesgue measure of ∞ is possible, but even so, assuming the axiom of choice, not all subsets of Rn are Lebesgue measurable.
It is possible to attach a probabilistic interpretation to Lebesgue measure.
www.lycos.com /info/lebesgue-measure.html   (369 words)

  
 math lessons - Lebesgue integration
Lebesgue integration is a mathematical theory that defines the integral for a very large class of functions.
However, as the need to consider more irregular functions arose (for example, as a result of the limiting processes of mathematical analysis and the mathematical theory of probability) it became clear that more careful approximation techniques would be needed in order to define a suitable integral.
The Lebesgue definition considers a different class of easily-calculated integrals than the Riemann definition, which is the main reason the Lebesgue integral is better behaved.
www.mathdaily.com /lessons/Lebesgue_integration   (2653 words)

  
 integration
Instead of using the areas of rectangles, a method that puts the focus on the domain of the function, Lebesgue turned to the codomain of the function for his fundamental unit of area.
Lebesgue's technique for turning a measure into an integral generalizes easily to many other situations, leading to the modern field of measure theory.
The Lebesgue integral was deficient in one respect.
www.daviddarling.info /encyclopedia/I/integration.html   (542 words)

  
 [No title]
An introduction to the Lebesgue integral, Lebesgue measure, and convergence theorems, with application to function spaces such as the LP spaces.
In mathematics, the Lebesgue measure is the standard way of assigning a length, area or volume to subsets of Euclidean space.
A Lebesgue measure of ∞ is possible, but even so, assuming the axiom of choice, not all subsets of Rn are Lebesgue measurable.
lycos.com /info/lebesgue-measure.html   (369 words)

  
 7.4. Lebesgue Integral
Fortunately, for many simple functions the two integrals agree and the Lebesgue integral is indeed a generalization of the Riemann integral.
The Lebesgue integral has properties similar to those of the Riemann integral, but it is "more forgiving": you can change a function on a set of measure zero without changing the integral at all.
The new concept, the Lebesgue integral, agrees with the old one, Riemann integral, when both apply and removes some of the oddities mentioned before.
web01.shu.edu /projects/reals/integ/lebes.html   (1687 words)

  
 [No title]
Lebesgue's idea, in a nutshell, was: Don't partition the domain of the function; partition the range.
Finally, to get the Lebesgue integral, we can take partitions into equal sized intervals with more and more points; the Lebesgue integral is the limit as the number of points goes to infinity of the Lebesgue sums.
So the first step in carrying through Lebesgue's program is to come up with a useful, consistent, notion of measure for subsets of the real line which, for intervals, coincides with the length of the interval.
www.math.fau.edu /schonbek/realan/raf02l1.html   (1528 words)

  
 Welcome to Mathsoft
Oskolkov and I. Kudryavtsev, “Lebesgue constants” entry in Encyclopaedia of Mathematics, Reidel, 1988-1994; MR 96k:00002.
Watson, The constants of Landau and Lebesgue, Quart.
Lorch, The principal term in the asymptotic expansion of the Lebesgue constants, Amer.
www.mathsoft.com /mathsoft_resources/mathsoft_constants/ref/2171.asp   (409 words)

  
 Lebesgue, Henri Leon (1875-1941)
Lebesgue graduated from the École Normale Supériere and, from 1921, taught at the College de France.
He and Emile Borel founded the modern theory of functions of a real variable, Lebesgue's great contribution being his new general definition of an integral (1902), which became known as the Lebesgue integral (see integration).
Although the Lebesgue integral was an example of the power of generalization, Lebesgue himself wasn't a fan of generalization and spent the rest of his life working on very specific problems, mostly in analysis.
www.daviddarling.info /encyclopedia/L/Lebesgue.html   (188 words)

  
 Wikinfo | Integral
The concept of Riemann integration was developed first, and Lebesgue integrals were developed to deal with pathological cases for which the Riemann integral was not defined.
This approach is motivated by calculus, and is the main method used for calculating the area under the curve as described in the preceding paragraph, for functions given by formulae.
Both the Riemann and the Lebesgue integral are approaches to integration which seek to measure the area under the curve, and the overall schema in both cases is the same.
www.wikinfo.org /wiki.php?title=integral   (1053 words)

  
 Wiley::Lebesgue Measure and Integration: An Introduction
A superb text on the fundamentals of Lebesgue measure and integration.
It focuses on only the most fundamental concepts, namely Lebesgue measure for R and Lebesgue integration for extended real-valued functions on R. Starting with a thorough presentation of the preliminary concepts of undergraduate analysis, this book covers all the important topics, including measure theory, measurable functions, and integration.
Lebesgue Measure and Integration is the ideal text for an advanced undergraduate analysis course or for a first-year graduate course in mathematics, statistics, probability, and other applied areas.
www.wiley.com /WileyCDA/WileyTitle/productCd-0471179787.html   (238 words)

  
 The Lebesgue Stieltjes Integration Resource   (Site not responding. Last check: 2007-10-26)
Lateinisches Quadrat Ld Lebesgue L (Forts.) Leere Menge...
Lebesgue measure and integration, metric spaces, Banach spaces...
Theorem 2.5 Measure Constructions 2.5.1 Lebesgue Measure on (0, 1] 2.5.2 Construction of a...
www.integrationsell.info /lebesguestieltjesintegration   (261 words)

  
 Biographie : Henri Léon Lebesgue (28 juin 1875 [Rennes] - 26 juillet 1941 [Paris])
Dans cette thèse, Lebesgue présente la théorie d'une nouvelle intégrale, appelée depuis intégrale de Lebesgue, qui va considérément simplifier et amplifier l'étude des séries trigonométriques, et plus généralement toute l'analyse de Fourier.
Lebesgue s'appuie sur les travaux de Jordan, Borel et Baire pour présenter une théorie des fonctions mesurables, qui peuvent être très discontinues.
Etonnament peut-être, Lebesgue n'enseigna jamais sa propre théorie.
www.bibmath.net /bios/index.php3?action=affiche&quoi=lebesgue   (507 words)

  
 PlanetMath: Lebesgue measure
It became the prototypical example of what later became known simply as measure, a concept which unified such diverse objects as area, probability, and function.
I think you should point out that the 'lebesgue measurable' sets in this sense contains the borel sigma algebra, and that it coincides with the obvious measure on the intervals (a,b]!
Also it might be worth pointing out it's the unique such measure on the borel sigma algebra.
www.planetmath.org /encyclopedia/LebesgueMeasure.html   (211 words)

  
 [No title]
LEBESGUE NULL: Can be covered by countably many open intervals, the sum of whose lengths can be arbitrarily small.
Moreover, because the real line can be written as the union of a Lebesgue null set and a first category set, this latter sigma-ideal is a strengthening of "small" that is significantly stronger than what either of these two sigma-ideals separately provides for.
By outer regularity of Lebesgue measure, there exists a G_delta set in R containing these endpoints that has the same Lebesgue measure as the set of these endpoints.] Let G = H intersect C. I claim that G is a Lebesgue null and first category set that is not sigma-Jordan null.
www.math.niu.edu /~rusin/known-math/00_incoming/lebesgue   (2146 words)

  
 Body
Actually the formula is also true for Lebesgue integrals if we have the equivalent of the Fundamental Theorem of Calculus for Lebesgue integrals.
Suppose F is differentiable (everywhere) on [a, b] and that the derivative F' is Lebesgue integrable.
Suppose f is Lebesgue integrable and has an antiderivative F on [a, b].
www.math.nus.edu.sg /~matngtb/Calculus/Int_by_parts/Int_by_parts.htm   (1486 words)

  
 An Introduction to the Gauge Integral
Lebesgue's definition is appreciably more complicated, but Lebesgue's techniques yield better convergence theorems and, for the most part, more integrable functions.
The integrals of Lebesgue, Denjoy, Perron, and Henstock by Russell Gordon, 1994.
Every introductory textbook on Lebesgue integrals includes a short proof (due to Vitali) of the existence of a nonmeasurable set; the characteristic function of that set is then a nonmeasurable function.
math.vanderbilt.edu /~schectex/ccc/gauge   (4371 words)

  
 S.O.S. Mathematics CyberBoard :: View topic - lebesgue
As near as I can discern, it seems to relate to an idea of a set function that maps from a *set* instead of from a number, the way a probability maps from a subset of a sample space to number between 0 and 1.
The notion of the Lebesgue measure of a set can be thought of as a generalization of the notion of the length of an interval.
The importance of Lebesgue integrals lies on the theoretical side, in that it's easier to prove certain things by operating in a more general framework.
www.sosmath.com /CBB/viewtopic.php?t=1937   (339 words)

  
 Jal Choksi - A history of the convergence theorems of (Lebesgue) integration
In most courses on Lebesgue integration there are three main convergence results: (i) the monotone convergence theorem (MCT), (ii) Fatou's lemma, both for non-negative functions, (iii) the dominated convergence theorem (DCT) and its corollary (for finite total measure) the bounded convergence theorem (BCT).
first appears in a paper of Lebesgue in 1908, with a more detailed account in a paper in 1910.
The best reference book is Hawkins, Lebesgue's theory of integration, but our lecture may contain a few surprises, even to those who have read this book!
www.cms.math.ca /Events/winter99/abstracts/node89.html   (212 words)

Try your search on: Qwika (all wikis)

Factbites
  About us   |   Why use us?   |   Reviews   |   Press   |   Contact us  
Copyright © 2005-2007 www.factbites.com Usage implies agreement with terms.