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Category of metric spaces

Is there a standard/good reference text that does category of metric spaces? Say, it seems that by looking at this category one can recover everything about particular metric space up to scaling --- ...
Anton Petrunin's user avatar
7 votes
0 answers
493 views

A locally compact, complete metric space in which the closure of open balls coincide with the closed ball is Heine-Borel

I saw the following result stated without a proof in a paper about the isometry group of metric measure spaces: Let $X$ be a locally compact, complete metric space such that for all $x \in X$ and $R &...
Kaitei's user avatar
  • 99
6 votes
0 answers
813 views

Limit of metric spaces

Let $\{X_n\}_{n\in \mathbb{N}}$ be a collection of T2 topological spaces, with maps $f_n\colon X_n \to X_{n+1}$. These maps are continuous and open. Let $X$ be the direct limit of this system. Assume ...
Giulio's user avatar
  • 2,384
4 votes
0 answers
194 views

Are there any major differences in metric topologies and "non-symmetric" metric topologies

Let $X$ be a set and let $d:X\times X\rightarrow [0,\infty)$ satisfy all the axioms of a metric besides symmetry (i.e.: $d$ is a quasi-metric). Define a topology $\tau_{d:+}$ on $X$ induced by $d$ as ...
John_Algorithm's user avatar
4 votes
0 answers
147 views

Continuous extension preserving modulus of continuity

Let $X$ be a (non-empty) compact subset of $D(0,M):=\left\{x\in \mathbb{R}^n:\, \|x\|\leq M\right\}$, and let $f:X\rightarrow Y$ be uniformly continuous; for some metric space $Y$. Are there any ...
Catologist_who_flies_on_Monday's user avatar
4 votes
0 answers
159 views

Is there a name for this geometric property of metric spaces?

My research has lead me to metric spaces $(M, \rho)$ which have the following geometric property: Suppose $x, y \in M$ and $r, s > 0$ such that $(x, r) \neq (y, s)$, $B[y; s] \subseteq B[x; r]$, $...
Theo Bendit's user avatar
4 votes
1 answer
479 views

"monotone" homotopy?

This is a question about a concept that I call "monotone homotopy" which arises in a natural way in some topological situations. Let $X$ be a (bounded) metric space, $Y$ be a topological space and $A\...
reader2's user avatar
  • 101
3 votes
0 answers
80 views

String metric properties when extending strings

I am studying some aspects concerning string distance functions, and I am sure there are generic results available in the field of metric spaces, but I have not been able to find appropriate ...
Kikolo's user avatar
  • 91
3 votes
0 answers
89 views

Reference request: Projection operators in metric spaces

Given a metric space $(X,d)$ and a subset $S\subset X$, the projection $P_S$ onto $S$ is well-defined as a set valued function. I am interested in learning more about properties of these projections ...
JohnA's user avatar
  • 710
2 votes
0 answers
187 views

Statistical invariants of Riemannian manifolds

$\DeclareMathOperator\diam{diam}\DeclareMathOperator\rad{rad}\DeclareMathOperator\iso{iso}\DeclareMathOperator\com{com}\DeclareMathOperator\con{con}$A cheap way of defining invariants of Riemannian ...
Alex's user avatar
  • 159
2 votes
0 answers
58 views

A generalization of metrics taking values in partial orders

I'm investigating the origin of the following notion: Let $S=(S, +, <, 0)$ be a partially ordered semigroup with minimum $0$ (such that $<$ is invariant by the action of $+$ on both sides). A $S$...
Cla's user avatar
  • 775
2 votes
0 answers
235 views

Examples of doubling metric spaces

I keep reading a lot of metric space results which are frames for doubling metric spaces. However, besides some obvious examples (such as Euclidean case, discrete spaces, or quasi-symmetric images of ...
ABIM's user avatar
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2 votes
0 answers
59 views

Weak convexity in graphs

I asked the following question in MathStackExchange, but I did not get any answer, and I think that this might be the appropriate venue for the question. As we know, a finite undirected graph ...
Manolito Pérez's user avatar
2 votes
0 answers
122 views

First-countable topological monoids without local absorbing elements whose topology is induced by a semimetric

This is a follow up of Question 163246. For the reader's convenience, let me first copy&paste some basic definitions. We let a semimetric on a set $X$ be a function $d: X \times X \to [0,\infty]$ ...
Salvo Tringali's user avatar
1 vote
0 answers
48 views

Metrics on paths in digraphs

I'm looking for metrics (or even just symmetric dissimilarities) on finite paths in finite digraphs but not finding anything in the literature. Can anyone point me to references? I've looked in Deza ...
Steve Huntsman's user avatar
1 vote
0 answers
162 views

Gromov-Hausdorff relative compactness without curvature restrictions

A famous theorem of Gromov says that the set of compact Riemannian manifolds with $Ric \geq c$ and $\text{diam} \leq D$ is relatively compact in the Gromov-Hausdorff metric. Chapter 10 of the book by ...
SMS's user avatar
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