2
votes
1answer
91 views
Is this cube packing possible?
I know how to pack $5$ unit squares in a square of side length $2+\frac{\sqrt{2}}{2}$. Is there an $\varepsilon>0$ such that there exists a packing of $9$ unit cubes in a cube of …
2
votes
0answers
30 views
Regularity of Delaunay triangulation of a hypercube
First using a three dimensional unit cube as an example for the term "regularity", we can have two possible triangulations:
(A)
(B)
We say the lower triangulation is more "regul …
3
votes
1answer
66 views
Simplex with edges of length at least s having smallest circumradius
Is it true that of all $n$-simplices with edge lengths greater than or equal to some parameter $s$, the regular simplex with edge lengths $s$ has the smallest circumradius? It seem …
6
votes
0answers
81 views
Maximum number of Vertices of Hypercube covered by Ball of radius R
Let $R>0$ be given and let $H^n$ be the unit hypercube in $\mathbb{R}^n$. The problem I am facing is to find the maximum number of vertices of $H^n$ which can be covered by a close …
0
votes
1answer
73 views
Counting integer points in a Minkowski sum
We have known from Ehrhart theory that if $P$ is a $d$-dimensional polytope of $\mathbb R^n$ which has integer vertices then the number of integer points in $nP$ is a polynomial of …
23
votes
4answers
625 views
Can every $\mathbb{Z}^2$ disk be pinball-reached?
Let every point of $\mathbb{Z}^2$ be surrounded by a mirrored disk of radius $r < \frac{1}{2}$,
except leave the origin $(0,0)$ unoccupied by a disk.
Q. Is it the case that …
10
votes
0answers
235 views
Drawings of complete graphs with $Z(n)$ crossings
Hill conjectured that the minimum number of crossings in a drawing of the complete graph $K_n$ in the plane is exactly
$$Z(n) = \frac{1}{4} \bigg\lfloor\frac{n}{2}\bigg\rfloor \le …
1
vote
1answer
59 views
The discrete theory of compressible fluids dynamics
I am working on the discrete theory of compressible fluids dynamics, i.e., numerically solving and simulating the compressible fluids , we are interested in the way using discrete …
2
votes
1answer
117 views
Maintaining boundary of unit circle arrangement
I have a process which in each step creates a new unit circle and I am interested in maintaining the boundary of the resulting arrangement in linear time.
Is there anything known …
2
votes
0answers
49 views
Symmetric dominance regions surrounding a Gaussian prime
Let $z=a + b i$ be a complex number which is a Gaussian prime,
on neither the $x$- nor the $y$-axis.
So $a^2+b^2$ is a prime.
Construct a region $D(z)$ surrounding $z$ which is the …
2
votes
2answers
139 views
Questions on Discrete Exterior Calculus in numerial computing
I have several questions about the Discrete Exterior Calculus (DEC) in the numerical method for solving partial differential equation in physics:
(Discrete Exterious Calculus is t …
16
votes
3answers
752 views
Research trends in geometry of numbers?
Geometry of numbers was initiated by Hermann Minkowski roughly a hundred years ago. At its heart is the relation between lattices (the group, not the poset) and convex bodies. One …
3
votes
0answers
81 views
Graph drawing maximizing the volume of the convex hull
Given a graph $G=(V,E)$ and a length function $\ell:E\to\mathbb{R}_+$.
An embedding of the graph into the $d$-dimensional Euclidean space is a map $f:V\to\mathbb{R}^d$ such that $| …
3
votes
1answer
105 views
Triangulation of the surface determined by sampling two of its cross-sections
I have a data set that essentially looks like the picture below, i.e., it's given by sets of points in $\mathbb{R}^3$ that sample the cross-sections of a certain surface that in pr …
29
votes
6answers
2k views
A sudden smiley? :-)
This is a vague question, and I will no doubt be (properly!) chastised for posing it.
I would like to generate a set $S$ of points in $\mathbb{R}^3$—$|S|$ finite or infinite& …

