Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 4558

Euclidean, hyperbolic, discrete, convex, coarse geometry, metric spaces, comparisons in Riemannian geometry, symmetric spaces.

9 votes
1 answer
479 views

What does convergence in distribution "in the Gromov–Hausdorff" sense mean?

I am trying to understand this survey article by Le Gall on Brownian geometry, especially the statement of Theorem 1. The basic statement of the theorem is $$(m_n,d_n) \to (m_{\infty}, d_{\infty})$$ …
Matthew Kahle's user avatar
8 votes

Is there a dense subset of the real plane with all pairwise distances rational?

Victor Klee and Stan Wagon write about this and other fun problems in their book: Old and New Unsolved Problems in Plane Geometry and Number Theory
Matthew Kahle's user avatar
8 votes
1 answer
700 views

Upper bound for tetrahedron packing?

There have been several recent advances on packing regular tetrahedra in $\mathbb{R}^3$. All the results I've seen have been lower bounds -- first John Conway and Sal Torquato showed that there exist …
Matthew Kahle's user avatar
3 votes

Applications of the notion of of Gromov-Hausdorff distance

Facundo Memoli applied Gromov-Hausdorff distance to shape matching in his Ph.D. thesis. http://math.stanford.edu/~memoli/research.html (Wayback Machine, new website)
8 votes
1 answer
309 views

Longest induced cycles in random geometric graphs near criticality

We make a random geometric graph $X(n;r)$ as follows. Choose $n$ points uniformly, independently, in the unit square $[0,1]^2$, for vertices, and then connect a pair of vertices $\{ p,q \}$ by an edge …
Matthew Kahle's user avatar
5 votes
1 answer
295 views

Updated bounds or references for an old Erdős problem –– coloring the plane with multiple fo...

Define a graph $G_1$ where the vertices of $G_1$ are the points of the plane $\mathbb{R}^2$, and a pair of vertices $p, q$ is connected by an edge if and only if the Euclidean distance $d(p,q) =1$. Th …
Matthew Kahle's user avatar
11 votes
2 answers
3k views

Algorithm for embedding a graph with metric constraints

Suppose I have a graph $G$ with vertex set $V$, edge set $E \subseteq {V \choose 2}$, a poistive integer $d$, and a weight function $w:E \to \mathbb{R}^{+}$. Is there a nice algorithmic way to decide …
Matthew Kahle's user avatar
4 votes
Accepted

Average degree of contact graph for balls in a box

Torquato and Stillinger have a recent survey article that discusses some questions like this: Jammed hard-particle packings: From Kepler to Bernal and beyond They are particularly interested in rand …
Matthew Kahle's user avatar
33 votes

Open problems in Euclidean geometry?

The Unit Distance Problem asks: For a set of $n$ points in the plane, what is the maximal number $g(n)$ of unit distances realized among the ${n \choose 2}$ pairs? A properly scaled squar …