Non-Trivial Metric Spaces: Infinite Points by Convention?

In summary, the conversation discusses the concept of non-trivial metric spaces and whether they always have an infinite number of points. The speaker suggests that in most cases, non-trivial implies an infinite number of points, but there are exceptions such as finite sets with the discrete metric. These finite sets may not be considered "trivial" by some individuals, but they do not have as many applications or importance as other types of metric spaces.
  • #1
pivoxa15
2,255
1
Is it by convention that all non trivial metric spaces have an infinite number of points?

Just like all non trivial sequences has an infinite number of points.
 
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  • #2
What do you mean by "non-trivial"?
 
  • #3
Good one. Probably what I mean is the examples that appear in any textbook. So all examples of sequences in textbooks have them as infinite sequences. Do all examples of metric spaces have infinite number of points?
 
  • #4
Do all examples of metric spaces have infinite number of points?

Hmm. In algebra it is frequently used that polynomial spaces (sometimes finite) are metric spaces under a 'difference of degrees' type relation. No one calls it a metric space, but the three defining properties are invoked frequently.

But really my answer is yes, I have only seen metric space terminology in connection with topology and analysis, so non-trivial => infinite...
 
  • #5
A finite set with the "discrete metric": d(u,v)= 0 if u= v, 1 otherwise is a finite metric space. Is that what you would consider "trivial"? I wouldn't.
 
  • #6
Does a finite set with the discrete metric have any applications or anything else of importance?

A set like Q with the discrete metric is non trivial but there are an infinite number of points in it.
 

FAQ: Non-Trivial Metric Spaces: Infinite Points by Convention?

What is a non-trivial metric space?

A non-trivial metric space is a mathematical concept used to describe a set of points where the distance between any two points is defined by a function called a metric. This function satisfies certain properties, such as being positive and symmetric, and allows for the measurement of distance between points in the space.

How is a non-trivial metric space different from a trivial metric space?

A non-trivial metric space has an infinite number of points, whereas a trivial metric space only has a finite number of points. In a non-trivial metric space, the distance between any two points can be infinitely small, while in a trivial metric space, the distance between any two points is always a non-zero constant value.

What is meant by "infinite points by convention" in the context of non-trivial metric spaces?

Infinite points by convention refers to the idea that in non-trivial metric spaces, the number of points is considered to be infinite, even if the actual number of points in the space is finite. This allows for the measurement of distances between points that may be infinitely small, and allows for a more flexible and abstract understanding of metric spaces.

What are some examples of non-trivial metric spaces?

Some examples of non-trivial metric spaces include Euclidean space, which is the set of all points in three-dimensional space, and the set of real numbers with the metric defined as the absolute value of the difference between two numbers. Other examples include graphs, networks, and other abstract mathematical structures.

How are non-trivial metric spaces used in science?

Non-trivial metric spaces are used in various fields of science, such as physics, engineering, and computer science. They are used to model and analyze complex systems, such as the behavior of particles in quantum mechanics or the flow of information in computer networks. Non-trivial metric spaces are also used in data analysis and machine learning to measure similarities and differences between data points.

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