Understanding Normed Linear Spaces: Convergence in C[0,1]

In summary, the conversation is about understanding sequence convergence in a normed linear space and showing that if a sequence fn converges to f in C[0,1] with sup norm, it also converges with the integral norm. The idea is similar to how absolute value works in an ordinary metric space, where given an epsilon, there exists a value n_0 such that for all values n greater than n_0 and x in the interval [a,b], the supremum of the difference between f_n and f is less than epsilon.
  • #1
bugatti79
794
1
Folks,

I am looking at this task.

1) What does it mean to say a sequence converges in a normed linear space?

2) Show that if a sequence fn converges to f in C[0,1] with sup norm then it also converges with the integral norm?

Any idea on how I tackle these?

thanks
 
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  • #2
bugatti79 said:
1) What does it mean to say a sequence converges in a normed linear space?

2) Show that if a sequence fn converges to f in C[0,1] with sup norm then it also converges with the integral norm?
Do you know about sequence convergence in an ordinary metric space, say the real and/or complex numbers?
If so, then you have the same idea using the norm. After all, is that not how absolute value works?
 
  • #3
Plato said:
Do you know about sequence convergence in an ordinary metric space, say the real and/or complex numbers?
If so, then you have the same idea using the norm. After all, is that not how absolute value works?

Is it something along the line of

given $\epsilon > 0 $ there exist $ n_0 \in N$ s.t $|(fn-f) (x)|| < \epsilon $ for $n > n_0$ and $ x \in [a,b] $

ie $\forall \epsilon > 0$ there exist $n_0 \in N$ s.t $sup |(f_n-f)(x)|=sup|f_n(x)-f(x)|$ and $x \in [a,b]$ for both...
 

FAQ: Understanding Normed Linear Spaces: Convergence in C[0,1]

1. What is a normed linear space?

A normed linear space is a mathematical concept that combines the properties of a normed space and a linear space. It is a vector space with an additional structure of a norm, which measures the size or length of a vector.

2. What is the significance of convergence in C[0,1]?

Convergence in C[0,1] is important because it allows us to study the behavior of functions over a closed interval. It is used to determine if a sequence of functions approaches a limit function, and to analyze the accuracy of numerical methods.

3. How is convergence in C[0,1] defined?

In C[0,1], convergence is defined as the property that for any given epsilon greater than 0, there exists an N such that for all n greater than N, the distance between the nth term of the sequence and the limit function is less than epsilon.

4. What are some applications of understanding normed linear spaces and convergence in C[0,1]?

Understanding normed linear spaces and convergence in C[0,1] has various applications in fields such as functional analysis, numerical analysis, and mathematical physics. It is also used in signal processing, control theory, and optimization problems.

5. How does convergence in C[0,1] relate to uniform convergence?

Convergence in C[0,1] is a type of uniform convergence, which means that the distance between the terms of the sequence and the limit function is constant for all points in the closed interval. However, not all types of convergence in C[0,1] are uniform.

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