# Questions tagged [uniform-spaces]

In the mathematical field of Topology, a uniform space is a generalization of the concept of metric spaces in which, unlike what happens in general topological spaces, it is possible to compare neighborhoods of distinct points. In uniform spaces, it is possible to define the concepts of uniform continuity, uniform convergence, and of complete space (as in the metric spaces, but unlike what happens in topological spaces in general).

279 questions
Filter by
Sorted by
Tagged with
36 views

### Does every net has a convergent subnet in a compact uniform space?

We know that Result 1: In a metric space compactness implies sequential compactness, that is, if $(X,d)$ is a compact metric space then every sequence $\{x_n\}$ in $X$ has a convergent subsequence. In ...
27 views

### Delone sets in terminology of uniformities

I've been reading about Delone sets recently, and noticed that they are formulated either in terms of topological groups or in terms of metric spaces. Group terminology: Let $G$ be a locally compact ...
1 vote
24 views

### Contraction principle type theorems for uniform spaces

I was recently wondering whether there are conraction principle like theorems for uniform spaces but which are not metric spaces. The theorem relies heavily on the notion of completeness, which exists ...
25 views

### Certain properties of uniform structure

I am trying to read about unifrom spaces from Introduction to Uniform Spaces, and I was wondering about some basic facts which I wasn't able to find there. Let $(X,\mathcal{E})$ be a uniform space. ...
25 views

### Entourage asymmetry and Cauchy nets: $x_a$ is $V$-close to $x_b$ does not imply $x_b$ is $V$-close to $x_a$

I have a few quibbles about the nature of the ordering $(a,b)$ versus $(b,a)$ when it comes to membership of an entourage in a uniform space. The Wikipedia article on uniform spaces nowhere asserts ...
40 views

28 views

65 views

19 views

### Does normal space guarantees existence of normal cover

Let $X$ be a topological space and $\mathcal{U}$ be an open cover of $X$. Define $st(M)=\{ U\in\mathcal{U}\vert M\cap U \neq \emptyset \}$ where $M$ is an arbitrary subset of $X$. A cover $\mathcal{V}$...
55 views

### Alternative characterisation of weakly complete Banach spaces

Let $V$ be a topological vector space over some locally compact field $\Bbb K$. Let $V'$ denote all continuous functionals on $V$, the weak topology is defined to be the coarsest topology on $V$ ...
82 views

### Topology of local uniform convergence

Let X be a topological space and Y a uniform space. Does there exist a topology of local uniform convergence on $Y^X$?
135 views

### Equivalence of metric

Definition 1. Two metrics $d_{1}$, $d_{2}$ on a set $X$ are equivalent, if there exist two positive numbers $c$, $c'\in\mathbb{R}_{> 0}$, such that if $x$, $y\in X$ then c d_{2}(x, y)\leq d_{1}(...
23 views

### Relation between entourages and finite open covers of compact Hausdorff spaces

Let $X$ be a compact Hausdorff space and $\mathcal{V}$ be a finite open cover of $X$. Since $X$ is a compact Hausdorff space, hence it has a uniformity $\mathcal{U}$. Is there an entourage $D$ in ...
49 views

42 views

29 views

### A question regarding 'Uniformization' theorem : connection between a topological space and a uniform spaces

This title might be slightly misleading since I saw that the name 'uniformization' theorem is already used in a different context, but my question regards whether a topological space arises from a ...
1 vote
32 views

### Is there a sequence of nested entourages $\{U_n\}$ with $\bigcap U_n=\Delta_X$, if $X$ is compact Hausdorff uniform space

Let $(X, \mathcal{U})$ be a compact Hausdorff uniform space. It is known that $\bigcap \{U: U\in \mathcal{U}\}= \Delta_X$. Is there a sequence $\{U_n\}_{n\in\mathbb{N}}$ with $U_{n+1}\subseteq U_n$ ...
43 views

### Motivation for Uniform Cover definition of Uniform Space

The Uniform Cover definition of a Uniform Space is - A uniform space $(X,\Theta)$ is a set $X$ equipped with a distinguished family of uniform covers $\Theta$ from the set of coverings of $X$, ...
1 vote
Kelley in his book General Topology introduces a notion of even cover. A cover $\mathcal{U}$ of a topological space $X$ is even if there exists a neighborhood $\mathcal{V} \subset X \times X$ of the ...