Skip to main content

All Questions

Tagged with
Filter by
Sorted by
Tagged with
1 vote
0 answers
123 views

Growth polynomial of the Associahedron graph ? (Is it approximately Gaussian ?)

Consider Associahedron, consider graph build from its vertices and edges. Choose some vertex. Let us count the number of vertices on distances $k$ from the selected vertex. Write a generating ...
Alexander Chervov's user avatar
1 vote
0 answers
82 views

A face and all its neighbors: terminology?

Suppose $F$ is a face of a 2-complex, and $F_1,\dotsc,F_n$ are the faces that are adjacent to (i.e., share an edge with) $F$. Is there a standard term for a collection of faces of the form $\{F,F_1,\...
James Propp's user avatar
  • 19.7k
2 votes
0 answers
138 views

Distinguishable knots (with constraints) over polyhedra

I'm trying to find the number of distinguishable knot projections over certain convex regular polyhedra according to the following constraints. On each face on the polyhedron the knot will have a ...
David G. Stork's user avatar
4 votes
2 answers
243 views

Clustering of vertices in an $n$-dimensional cube

Consider the vertices of an $n$-dimensional cube. The distance between two vertices is measured as the minimum number of edges between the two vertices. Now consider a subset of these vertices. If we ...
Vaisakh M's user avatar
3 votes
0 answers
222 views

Reconstructing plane graphs from degree- and face-sequences

Let $G$ be a plane $3$-connected graph; so it partitions the plane into regions bounded by faces. Let $\mathrm{deg}_v$ be the sequence of vertex degrees of $G$, and $\mathrm{deg}_f$ be the sequence of ...
Joseph O'Rourke's user avatar
4 votes
0 answers
229 views

Harborth's conjecture and polyhedra

Harborth's conjecture states that every planar graph can be drawn on a plane only using staight line segments of rational or integral edge length. ( There is a good mathoverflow page for this ...
Seonhwa  Kim's user avatar
4 votes
1 answer
289 views

Convex polyhedra, combinatorial types and Symmetry

Steinitz theorem says that combinatorial types of convex polyhedra is identified with 3-connected planar graph, called by a polyhedral graph. A symmetry of polyhedral graph means that a vertex ...
Seonhwa  Kim's user avatar
9 votes
3 answers
436 views

Labeling edges of an icosahedron with sum constraints

The question is inspired by this previous MO question. There it was shown that it's possible to label the edges of a cube by the numbers $\{1,2,\ldots,6,8,9, \ldots, 13\}$ in such a way that: Three ...
François Brunault's user avatar
5 votes
2 answers
1k views

regular polyhedra (and polytopes) in hyperbolic geometry, and generalisations

While there exist regular tesselations of the hyperbolic plane with arbitrary regular polygons, there are no new regular polyhedra in hyperbolic (3D) space. This being quite trivial, it is probably ...
Feldmann Denis's user avatar
8 votes
7 answers
2k views

Visualizing polyhedra from their 1-skeletons

Except for a few simple cases (typically pyramids and prisms) I find it hard to visualize a polyhedron from its 1-skeleton embedded in the plane, e.g. the hexahedral graph 5, as can be seen here. ...
Hans-Peter Stricker's user avatar
1 vote
2 answers
1k views

Does Euler's formula imply bounds on the degree of vertices in a 3-polytopal graph?

A corollary of Euler's formula tells us that the edge-vertex graph of every convex 3-polyhedron must have a face with either 3, 4, or 5 edges, using an argument about the average degree of vertices. ...
Manifold Destiny's user avatar