Understanding Example from Topics in Banach Space Integration

Click For Summary
SUMMARY

The discussion focuses on the proof of a statement from the book "Topics In Banach Space Integration" by Ye Guoju and Schwabik Stefan. The statement asserts that if a function f is integrable on a Banach space X, then a sequence of simple functions can converge to f in the norm of X. The technique of "cutting and pasting" is recommended for proving this statement, which involves dividing the integral of f into smaller intervals and approximating each with simple functions. The authors illustrate this process with a specific example, demonstrating the convergence of simple functions to the original function within the Banach space.

PREREQUISITES
  • Understanding of Banach space theory
  • Familiarity with the concept of integrability in functional analysis
  • Knowledge of simple functions and their properties
  • Basic skills in limit processes and convergence in normed spaces
NEXT STEPS
  • Study the proof techniques for integrability in Banach spaces
  • Explore the concept of simple functions in functional analysis
  • Learn about the properties of convergence in normed spaces
  • Review examples of integrable functions in various Banach spaces
USEFUL FOR

Mathematicians, students of functional analysis, and researchers interested in the properties of Banach spaces and integrability concepts.

Sara jj
Messages
2
Reaction score
0
Hey

Could you give me a hint how to explain this example?
Need help to prove statement in red frame.

Example from book (Topics In Banach Space Integration)
by Ye Guoju‏، Schwabik StefanThank you
 

Attachments

  • ex2.png
    ex2.png
    17.6 KB · Views: 146
Physics news on Phys.org
Sara jj said:
Hey

Could you give me a hint how to explain this example?
Need help to prove statement in red frame.

Example from book (Topics In Banach Space Integration)
by Ye Guoju‏، Schwabik StefanThank you

It's a bit hard to use something that you haven't given us...
 
for your post! To explain the example from the book, let's first define the statement in the red frame: "If a function f is integrable on a Banach space X, then there exists a sequence of simple functions converging to f in the norm of X."

This statement is essentially saying that any integrable function on a Banach space can be approximated by a sequence of simple functions in the same space. To prove this, we can use a technique called "cutting and pasting," where we divide the integral of f into smaller intervals and approximate each interval with a simple function. Then, by taking the limit of these simple functions, we can show that they converge to f in the norm of X.

In the book, the authors provide an example of how this technique can be applied to a specific function and Banach space. By following their steps and using the definition of integrability and the properties of Banach spaces, we can see how the sequence of simple functions converges to the original function in the given Banach space.

I hope this helps to explain the example in the book. Let me know if you have any further questions or need clarification.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
Replies
2
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K