Uniformity of Space: Definition & Examples

In summary, there is a question about the terminology for a space X with the property that for all x, x' in X and neighborhood N of x, N is homeomorphic to some neighborhood N' of x' or for all x, x' there exists a homeomorphism f:X→X s.t. f(x)=x'. This property is not equivalent to continuous bijection, as the continuous inverse is also required for homeomorphism.
  • #1
alexfloo
192
0
"Uniformity" of space

I have a question about terminology. Suppose we have a space X with the property that:

for all x, x' in X and neighborhood N of x, N is homeomorphic to some neighborhood N' of x'
OR
for all x, x' there exists a homeomorphism f:X→X s.t. f(x)=x'.

(I believe these are equivalent, but I haven't worked it out.) In some sense, these spaces are uniform (although I know that uniform space has its own meaning). There are no "distinguished" points, or different "types" of points. (Any open, simply-connected subset of Euclidean space has this property. Any closed subset of Euclidean space not equal to its boundary lacks it, since boundary points cannot be continuously mapped onto interior points.)

Is there a name for this?

EDIT: fixed an error.
 
Last edited:
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  • #2


actually those 2 sentences are not equivalent since the continuous bijection doesn't guarantee the homeomorpic between neighborhood of x and x' , it must have continuous inverse to be homeomorphic
 
  • #3


EDIT: You are correct. I'll add that in.
 
  • #4


alexfloo said:
Continuous bijection should be sufficient:

Continuous X→Y means for each open OY subset of Y, f-1(OY)=OX is open in X. Bijection means that

f(OX)=f(f-1(OY))=OY,

so f-1 is also continuous.

Now you assume that all open sets are of the form [itex]f^{-1}(O_Y)[/itex]. This is not necessarily true.
 
  • #5


This property is known as uniformity of space or uniform continuity. It means that the space does not have any distinguishing features or singularities, and all points are equivalent in terms of their local neighborhoods. This is a desirable property in many mathematical and scientific contexts, as it allows for simpler and more uniform analysis and understanding of the space. However, it is important to note that this is not the same as a uniform space, which has a more specific definition in mathematics.
 

What is the definition of uniformity of space?

Uniformity of space refers to the idea that the space of our universe is consistent and evenly distributed in all directions. This means that no matter where we are in the universe, the laws of physics and the properties of space remain the same.

How is uniformity of space measured?

Uniformity of space is measured through various cosmological observations and experiments. One of the key measures is the cosmic microwave background radiation, which is a remnant of the early universe and is expected to be uniform in all directions.

What are some examples of uniformity of space?

One example of uniformity of space is the isotropic nature of the cosmic microwave background radiation, which has been observed to have the same temperature in all directions. Another example is the homogeneity of matter distribution in the universe on large scales.

Why is uniformity of space important in cosmology?

Uniformity of space is important in cosmology because it is one of the key assumptions of the standard model of cosmology, known as the cosmological principle. This principle states that the universe is homogeneous and isotropic on large scales, and it allows us to make accurate predictions about the evolution of the universe.

What are the implications of non-uniformity of space?

If the universe was not uniform in space, it would have significant implications for our understanding of the universe and the laws of physics. It could challenge the cosmological principle and require us to rethink our current models and theories of the universe's origin and evolution.

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