Proving a true fact about measure theory and integration

In summary, the problem is to prove that the sequence \left(\int_{E_n} f\right)_{n \geq 0} converges to 0 as n \to \infty. One possible approach is to use countable additivity and the continuity of integration. After Case 1, which involved integrating over an empty set, it may be helpful to consider writing the sets in the sequence as unions of disjoint sets. Another idea is to use a telescoping series to find the limit of \int_E f and consider the sequence of partial sums.
  • #1
jdinatale
155
0
attempt_zps504ff0e4.png


So the above is the problem and my idea of how to approach it. This problem comes from the section on the Countable Additivity of Integration and the Continuity of Integration, but I was not sure how to incorporate those into the prove, if you even need them for the result.

I had no idea what to do after Case 1, leading me to believe that that approach is wrong.
 
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  • #2
Case 1 is just silly - all you did was observe that if you integrate over an empty set you get zero. Don't think that there's any way to generalize it to the unbounded case.Countable additivity is one definite option for solving this problem. Your Ens are not disjoint, but can you think of a way to write down some disjoint sets whose unions can give you the various Ens?
 
  • #3
jdinatale said:
So the above is the problem and my idea of how to approach it. This problem comes from the section on the Countable Additivity of Integration and the Continuity of Integration, but I was not sure how to incorporate those into the prove, if you even need them for the result.

I had no idea what to do after Case 1, leading me to believe that that approach is wrong.

The problem is telling me that I want to prove that the sequence [itex]\left(\int_{E_n} f\right)_{n \geq 0}[/itex] converges to 0 as [itex]n \to \infty[/itex].

Hint: Find a telescoping series whose limit is [itex]\int_E f[/itex], and look at the sequence of partial sums.
 

1. What is measure theory and integration?

Measure theory is a branch of mathematics that deals with the properties of measures, which are used to quantify the size or extent of a set. Integration is the process of finding the area under a curve, which is a fundamental concept in calculus. In measure theory and integration, we use measures to extend the notion of integration to more general sets and functions.

2. Why is measure theory important?

Measure theory is important because it provides a rigorous mathematical framework for dealing with measures and integration. It allows us to define and study these concepts in a more general setting, which is crucial for applications in various fields such as physics, economics, and engineering.

3. How do you prove a true fact about measure theory and integration?

To prove a true fact about measure theory and integration, we must use the axioms and definitions of measure theory to logically deduce the desired result. This often involves constructing a rigorous mathematical proof that shows the truth of the statement in all cases.

4. What are some common techniques used in proving facts about measure theory and integration?

Some common techniques used in proving facts about measure theory and integration include the use of measure-preserving transformations, the Lebesgue differentiation theorem, and the Radon-Nikodym theorem. These tools allow us to manipulate and analyze measures and functions in a more systematic and efficient way.

5. How is measure theory and integration applied in real-world problems?

Measure theory and integration have many practical applications, such as in physics, engineering, and economics. For example, in physics, measures and integration are used to calculate the volume of irregularly shaped objects or the total charge and energy of a system. In economics, they are used to analyze risk and probability in financial markets. In general, measure theory and integration provide a powerful mathematical tool for solving real-world problems that involve quantities and their distributions.

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