0
votes
0answers
48 views
Circle segment of exact length [closed]
I need to find:
a spherical line
that passes through the points 0,0 and 8,8
and the distance of the line between those two points must be exactly 12
I imagine the answer will b …
17
votes
2answers
602 views
How can I randomly draw an ensemble of unit vectors that sum to zero?
Inspired by this question, I would like to determine the probability that a random knot of 6 unit sticks is a trefoil. This naturally leads to the following question:
Is there a …
7
votes
1answer
162 views
Question about tetrahedron decomposition
Are there tetrahedra which can be subdivided into three parts similar to the original? I believe this would require splitting one face into three parts. I know some types of tetrah …
0
votes
0answers
94 views
What is barycentric simplicial subdivision? [closed]
In A Generalization of Brouwer's Fixed Point Theorem by Shizuo Kakutani, he defined $S^{(n)}$ be the $n$-th barycentric simplicial subdivision of $S$. In which $S$ is an $r$-dimens …
2
votes
1answer
104 views
Is there an “accepted” jamming limit for hard spheres placed in the unit cube by random sequential adsorption?
I have a unit cube, and operating in the continuum limit (i.e. not on a lattice), I sequentially place spheres of some radius $r$ inside the cube until a filled volume "jamming lim …
2
votes
0answers
19 views
Diameters of the images of two balls under a function
Let $ \Omega $ be an open and bounded subset of $ \mathbb{R^n} $, and let $ f:\Omega \to \mathbb{R} $ be a continuous function. I'm looking for some (preferably, minimal) condition …
5
votes
1answer
185 views
Reference request: affine transforms + circle inversion?
This problem cropped up in the context of scale-insensitive methods for generating random variables.
Let $X=R^n \cup \{\infty\}$. Suppose we consider a set of transforms $\cal{T} …
1
vote
1answer
100 views
General and translational Birkhoff lattices. Equational classes.
By lattice I'll mean Birkhoff lattice.
The two classical equational classes of lattices are modular lattices and distributive lattices. The old problem used to b …
3
votes
1answer
151 views
Sums of uniformly random vectors from the $n$-dimensional unit ball
I'm interested in some instances of the following problem.
Let $n \geq 2$, and suppose we draw $k \geq 2$ vectors $v_1, \dots, v_k$ uniformly at random from the $n$-dimensional …
1
vote
0answers
73 views
A question on the theorem of Minkowski-Hlawka
The Minkowski-Hlawka theorem (as stated by Gruber in his lovely book Convex and Discrete Geometry) says that if $S$ is a Jordan measurable set in $\mathbb{R}^n$ with volume < 1. …
3
votes
1answer
70 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 …
2
votes
2answers
258 views
Triangle area on surfaces of constant curvature
I am looking for an elementary derivation of the formula for the area of a geodesic triangle lying in a surface of constant curvature $\kappa$, depending on the angles and side len …
1
vote
4answers
102 views
How to find overlap between two convex hulls,along with the overlap area
I have two boundaries of two planar polygons , say,B1 and B2 of polygons P1 and P2(with m and n points in Boundaries B1 and B2). I want to find out if the Polygons overlap or not.I …
7
votes
3answers
472 views
Applications of visual calculus
Mamikon's visual calculus (see Mamikon, Tom Apostol, Wikipedia) is a very beautiful and surprisingly efficient tool.
The basis is
Mamikon's theorem. The area of a tangent swee …
0
votes
1answer
70 views
Trilateration problem
When trying to develop an algorithm for a program, I got with the following problem:
Determine the approximate location of $O$, if you can take finite samples $P_n$ from known loc …

