Monotone convergence theory

In summary, the statement "Every bounded and monotone sequence of real numbers is convergent" is equivalent to the monotone convergence theorem, which can be proven in different ways such as defining real numbers as equivalence classes of monotone sequences or as Dedekind cuts. Other properties such as the least upper bound property, Cauchy Criterion, connectedness of the real numbers, and compactness of closed and bounded sets are all equivalent to this theorem and can be easily proven given one of them.
  • #1
jmazurek
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Is the statement "Every bounded and monotone sequence of real numbers is convergent" proved my the monotone convergence theory? Thanks!
 
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  • #3
jmazurek said:
Is the statement "Every bounded and monotone sequence of real numbers is convergent" proved my the monotone convergence theory? Thanks!

?? That IS the "monotone convergence theorem".

One way to prove it is to define the real numbers as "equivalence classes of monotone sequences" where {an} is equivalent to {bn} if and only if {an-bn} converges to 0.

Another way is to define real numbers as Dedekind cuts which makes it easy to prove the "least upper bound" property and use that to prove the least upper bound theorem.

The "least upper bound property", "monotone convergenence", "Cauchy Criterion", "connectedness of the real numbers", and "every closed and bounded set is compact" are all equivalent- given anyone you can prove the others. They are all "fundamental" in the sense that you can define the real numbers in ways that make it easy prove on or the other of these.
 

Related to Monotone convergence theory

1. What is Monotone Convergence Theory?

Monotone Convergence Theory is a fundamental concept in mathematical analysis, specifically in the study of sequences and series of real numbers. It states that if a sequence is monotone (either increasing or decreasing) and bounded, then it will converge to a limit.

2. What does it mean for a sequence to be monotone?

A sequence is monotone if its terms are either always increasing or always decreasing. In other words, the sequence is either always greater than or equal to the previous term (monotonically increasing) or always less than or equal to the previous term (monotonically decreasing).

3. How does Monotone Convergence Theory differ from other convergence tests?

Unlike other convergence tests, such as the Ratio Test or the Root Test, Monotone Convergence Theory does not require the terms of a sequence to decrease or increase at a specific rate. It only requires the sequence to be monotone and bounded for it to converge.

4. What is the importance of Monotone Convergence Theory?

Monotone Convergence Theory is a crucial tool in mathematical analysis as it allows us to prove the convergence of a sequence without having to explicitly find its limit. This is particularly useful in more complex mathematical problems where finding the limit may not be feasible.

5. Can Monotone Convergence Theory be applied to all sequences?

No, Monotone Convergence Theory only applies to monotone and bounded sequences. If a sequence is not monotone or unbounded, then this theory cannot be used to prove its convergence. Other convergence tests would need to be applied in these cases.

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