Topological property of the Cantor set

In summary, to prove that a metric separable and zero-dimensional space X is homeomorphic to a subset of the Cantor set, one can use the theorem that states if X is a T_1 space and has a countable basis of clopen sets, then the evaluation map is an embedding. One can construct functions from X into the product space and apply the theorem to show that the resulting function is injective, due to X being Hausdorff.
  • #1
hedipaldi
210
0
Let X be a metric separable metric and zero dimensional space.Then X is homeomorphic to a subset of Cantor set.
How can it be proved?
Thank's a lot,
Hedi
 
Physics news on Phys.org
  • #2
Hint: prove the following theorem:

  • Let ##X## be a ##T_1## space (= singletons are closed). Let ##\{f_i~\vert~i\in I\}## be a collection of functions ##f_i:X\rightarrow X_i## which separates points from closed sets, then the evaluation map ##e:X\rightarrow \prod_{i\in I}X_i## is an embedding.

Now, your space ##X## has a countable basis consisting of clopen sets (why?). Use this to construct functions ##f_n:X\rightarrow \{0,1\}## for ##n\in \mathbb{N}## and apply the theorem.
 
  • #3
Thank you.
 
  • #4
Injectivity of the function

The resulting function from X into the product space doesn't seem to be one-to-one.Maybe i fail to see something?
 
  • #5
After further thinking i suppose injectivity is due to X being Haussdorff.Am i right?
 

1. What is the Cantor set?

The Cantor set is a mathematical set that is created by repeatedly removing the middle third of a line segment. This set is also known as the Cantor ternary set or the Cantor dust.

2. How is the Cantor set related to topology?

The Cantor set is a fundamental example in topology as it exhibits many topological properties, such as being compact, perfect, and totally disconnected.

3. What is the topological dimension of the Cantor set?

The topological dimension of the Cantor set is 0. This means that the set has no interior points and behaves like a zero-dimensional object.

4. Can the Cantor set be expressed as a union of countably many closed sets?

Yes, the Cantor set can be expressed as a union of countably many closed sets. This is because the set is constructed by removing smaller and smaller closed intervals, and the resulting set is the union of all these intervals.

5. What are some applications of the Cantor set in science?

The Cantor set has applications in various fields of science, including physics, computer science, and neuroscience. It is used to construct fractal patterns and models of self-similarity, and also has applications in coding theory and signal processing.

Similar threads

  • Differential Geometry
Replies
7
Views
3K
Replies
4
Views
1K
Replies
1
Views
3K
Replies
4
Views
2K
  • Topology and Analysis
2
Replies
61
Views
1K
  • Differential Geometry
Replies
7
Views
4K
  • Science and Math Textbooks
Replies
24
Views
3K
  • Special and General Relativity
Replies
25
Views
2K
  • Topology and Analysis
Replies
5
Views
216
  • Topology and Analysis
Replies
12
Views
2K
Back
Top