Convergence of Sequence ##(p_n)## to ##p##

In summary, the conversation discusses the construction of a sequence that converges to a limit point in a metric space. The proposed method involves defining the sequence as the set of distances between the limit point and points in the space, divided by the index of the sequence. However, it is noted that this method may not work in all spaces and a more rigorous proof is needed.
  • #1
Bachelier
376
0
If ##p## is a limit point of ##E## then ##\exists \ (p_n) \ s.t. (p_n) \rightarrow p##

For the sequence construction, can I just define ##(p_n)## as such:

##For \ q \in E, \ \ define \ (p_n) := \left\{\Large{\frac{d(p,q)}{n}} \right\}_{n=1}^\infty##​
 
Physics news on Phys.org
  • #2
Are you assuming E is subset of R?

Try E = {1}.

Edit: I also think your definition of limit point is wrong.
 
  • #3
pwsnafu said:
Are you assuming E is subset of R?

Try E = {1}.

Edit: I also think your definition of limit point is wrong.

Thanks. I am not looking for the def. of ##l.p.##, rather the theorem that states we can alway construct a seq. converging to any limit point.

Rudin uses a different proof, but I just thought about this one and wanted to see if it is correct.
 
  • #4
Bachelier said:
Thanks. I am not looking for the def. of ##l.p.##, rather the theorem that states we can alway construct a seq. converging to any limit point.

Rudin uses a different proof, but I just thought about this one and wanted to see if it is correct.

I assume you're working in ##\mathbb{R}^n##? This is true in metric spaces. It's not true in general. Your approach is correct, though your proof is not correct as written. You need to be more rigorous about how you're selecting elements for your subsequence.
 
  • #5
Notice your sequence is a collection of numbers, which are not necessarily points in your space (i.e., outside of the reals, that I can think of ). For example, in R^n, for n>1, the sequence of numbers d(p,q)/n is not a collection of points in your space.
 
Last edited:

FAQ: Convergence of Sequence ##(p_n)## to ##p##

What does it mean for a sequence to converge?

A sequence converges if its terms approach a specific value as the sequence progresses. In other words, the terms of the sequence get closer and closer to a specific number as the sequence continues.

How is convergence of a sequence determined?

The convergence of a sequence is determined by taking the limit of the sequence as the number of terms approaches infinity. If this limit exists and is equal to a specific number, then the sequence is said to converge to that number.

What is the importance of convergence in mathematics?

Convergence is a fundamental concept in mathematics and is used in many areas of the subject, such as calculus, analysis, and statistics. It allows us to define and analyze infinite processes and make predictions about their behavior.

What is the difference between pointwise and uniform convergence?

Pointwise convergence means that for each individual term in the sequence, the value approaches the limit as the number of terms increases. Uniform convergence means that the entire sequence converges to the limit, not just each individual term.

Can a sequence have multiple limits?

No, a sequence can only have one limit. If a sequence has multiple limits, then it is not convergent. However, a sequence may not have a limit at all, in which case it is said to be divergent.

Similar threads

Replies
2
Views
1K
Replies
1
Views
2K
Replies
32
Views
6K
Replies
2
Views
2K
Replies
1
Views
1K
Replies
44
Views
5K
Replies
2
Views
1K
Replies
4
Views
2K
Back
Top