# Analysis with or without set-theoretic topology?

• Calculus
• inthenickoftime
In summary, a first course in analysis should teach basic techniques in estimation, introduce core concepts of set-theoretic topology, and be open to introducing new notions (propositional logic, sets, topology, etc.) if they are relevant to the subject at hand. It is up to the instructor to decide when these new notions should be introduced, and ultimately it is up to the student to decide whether or not they are interested in these new concepts.
inthenickoftime
Do you think a first course in analysis should focus entirely on inequalities and leave set-theoretic topology for another occasion? Should this depend on whether or not the student had a first rigorous calculus course first? If I'm not mistaken, Victor Bryant (Yet Another Introduction to Analysis) and Arthur Mattuck (Introduction to Analysis) authored analysis books in the language of inequalities. Has anyone had previous experience with these two? Did it alleviate topological proofs in later courses? Is topology even required for the level I'm aiming at? Let's say my main concern is grasping the calculus of variations (much needed in mechanics). At what point do you absolutely need to incorporate topology in your analysis?

edit: I'd like to add that David Bressoud's A Radical Approach to Analysis also does this.

Last edited:
inthenickoftime said:
Do you think a first course in analysis should focus entirely on inequalities and leave set-theoretic topology for another occasion?
I think that a first course should do both: teach basic techniques in estimation, but also introduce core concepts of set-theoretic topology. At a more advanced level, these often go hand in hand.
inthenickoftime said:
Should this depend on whether or not the student had a first rigorous calculus course first?
No, as part of the purpose of a first course in analysis is to make calculus rigorous.
inthenickoftime said:
Victor Bryant (Yet Another Introduction to Analysis) and Arthur Mattuck (Introduction to Analysis) authored analysis books in the language of inequalities. Has anyone had previous experience with these two?
No, sorry, I have no experience with those texts.
inthenickoftime said:
Is topology even required for the level I'm aiming at? Let's say my main concern is grasping the calculus of variations (much needed in mechanics). At what point do you absolutely need to incorporate topology in your analysis?
It really depends on what level of understanding you are striving for, and what you aim to do with the theory that you will learn. For example, a lemma by Weierstrass says that a continuous real-valued function (i.e. a continuous functional) on a compact topological space assumes its maximum and minimum. Now, calculus of variations is typically concerned with the case that the domain of the functional is a subset of an infinite dimensional topological vector space. In this setting, it is typically not easy for that domain to be compact, and both compactness and continuity depend very much on the topology in question.

I'm quite sure there are lots of physicists that use calculus of variations successfully (for example in mechanics) without worrying about topological issues. On the other hand, it are precisely those issues that I find more interesting myself.

So, my advice would be to get a rigorous introduction to analysis that offers a broad perspective and does not limit itself to one very specific approach. You can always study such approaches in tandem or (maybe better) after having finished your introduction.

inthenickoftime
I am not sure of the answer to your question, but I have some experience. In my own math career I have found that basic topology is probably the most useful and fundamental language and knowledge there is, absolutely valuable to almost everyone, certainly to me. The introduction to John Kelley's General Topology said he was dissuaded with difficulty by friends from titling his book "What every young analyst should know". So in my opinion you will be glad for everything you learn from topology.

vanhees71 and inthenickoftime
Maybe I'm biased, but one cannot know too much topology. It is such a powerful tool. I use it all the time.

vanhees71
Topology is beautiful and useful, but for an introduction to analysis, I think it is best to find a balance between "soft" and "hard" analysis.

inthenickoftime
S.G. Janssens said:
Topology is beautiful and useful, but for an introduction to analysis, I think it is best to find a balance between "soft" and "hard" analysis.
I had to ask because topology and sets are relatively new. If I'm correct, people were doing rigorous mathematics long before these two branches were introduced (I can think of Fourier and Cauchy). The addition of new notions (propositional logic, sets, topology, etc.) to an already complex subject (calculus) when others have done without, and, successfully at that, made me wonder if the actual math curriculum isn't doing its students some disservice by obfuscating elements of calculus with the introduction of other topics prematurely. I'm not arguing against their use, but question their use within a first rigorous course on calculus.

## 1. What is analysis with or without set-theoretic topology?

Analysis with or without set-theoretic topology is a branch of mathematics that deals with the study of continuous functions and their properties. It involves analyzing functions and their behavior using the tools of set theory and topology.

## 2. What is the difference between analysis with and without set-theoretic topology?

The main difference between analysis with and without set-theoretic topology lies in the approach used to study continuous functions. Analysis with set-theoretic topology uses the concepts of open and closed sets, limit points, and convergence to analyze functions, while analysis without set-theoretic topology focuses on the algebraic properties of functions.

## 3. What are some applications of analysis with or without set-theoretic topology?

Analysis with or without set-theoretic topology has many practical applications in fields such as physics, engineering, and economics. It is used to model and analyze complex systems, study the behavior of dynamical systems, and solve optimization problems.

## 4. How is set-theoretic topology used in analysis?

Set-theoretic topology provides the foundation for analysis by defining the concepts of open and closed sets, limit points, and continuity. These concepts are essential for studying the properties of continuous functions and their behavior.

## 5. What are some important theorems in analysis with or without set-theoretic topology?

Some important theorems in analysis with or without set-theoretic topology include the Intermediate Value Theorem, the Mean Value Theorem, and the Fundamental Theorem of Calculus. These theorems are fundamental in understanding the behavior of continuous functions and their applications in various fields.

• Science and Math Textbooks
Replies
10
Views
5K
• Science and Math Textbooks
Replies
13
Views
2K
• Science and Math Textbooks
Replies
4
Views
2K
• Science and Math Textbooks
Replies
4
Views
3K
• Science and Math Textbooks
Replies
4
Views
1K
• Science and Math Textbooks
Replies
0
Views
768
• Topology and Analysis
Replies
2
Views
2K
Replies
11
Views
948