| Order-4-5 pentagonal honeycomb | |
|---|---|
| Type | Regular honeycomb | 
| Schläfli symbol | {5,4,5} | 
| Coxeter diagrams |        | 
| Cells | {5,4}  | 
| Faces | {5} | 
| Edge figure | {5} | 
| Vertex figure | {4,5} | 
| Dual | self-dual | 
| Coxeter group | [5,4,5] | 
| Properties | Regular | 
In the geometry of hyperbolic 3-space, the order-4-5 pentagonal honeycomb a regular space-filling tessellation (or honeycomb) with Schläfli symbol {5,4,5}.
Geometry
All vertices are ultra-ideal (existing beyond the ideal boundary) with five order-4 pentagonal tilings existing around each edge and with an order-5 square tiling vertex figure.
|  Poincaré disk model |  Ideal surface | 
Related polytopes and honeycombs
It a part of a sequence of regular polychora and honeycombs {p,4,p}:
| {p,4,p} regular honeycombs | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Space | S3 | Euclidean E3 | H3 | ||||||||
| Form | Finite | Paracompact | Noncompact | ||||||||
| Name | {3,4,3} | {4,4,4} | {5,4,5} | {6,4,6} | {7,4,7} | {8,4,8} | ...{∞,4,∞} | ||||
| Image |  |  |  |  |  | ||||||
| Cells {p,4} |  {3,4} |  {4,4} |  {5,4} |  {6,4} |  {7,4} |  {8,4} |  {∞,4} | ||||
| Vertex figure {4,p} |  {4,3} |  {4,4} |  {4,5} |  {4,6} |  {4,7} |  {4,8} |  {4,∞} | ||||
Order-4-6 hexagonal honeycomb
| Order-4-6 hexagonal honeycomb | |
|---|---|
| Type | Regular honeycomb | 
| Schläfli symbols | {6,4,6} {6,(4,3,4)} | 
| Coxeter diagrams |               =       | 
| Cells | {6,4}  | 
| Faces | {6} | 
| Edge figure | {6} | 
| Vertex figure | {4,6}  {(4,3,4)}  | 
| Dual | self-dual | 
| Coxeter group | [6,4,6] [6,((4,3,4))] | 
| Properties | Regular | 
In the geometry of hyperbolic 3-space, the order-4-6 hexagonal honeycomb is a regular space-filling tessellation (or honeycomb) with Schläfli symbol {6,3,6}. It has six order-4 hexagonal tilings, {6,4}, around each edge. All vertices are ultra-ideal (existing beyond the ideal boundary) with infinitely many hexagonal tilings existing around each vertex in an order-6 square tiling vertex arrangement.
|  Poincaré disk model |  Ideal surface | 
It has a second construction as a uniform honeycomb, Schläfli symbol {6,(4,3,4)}, Coxeter diagram, 




 , with alternating types or colors of cells. In Coxeter notation the half symmetry is [6,4,6,1+] = [6,((4,3,4))].
, with alternating types or colors of cells. In Coxeter notation the half symmetry is [6,4,6,1+] = [6,((4,3,4))].
Order-4-infinite apeirogonal honeycomb
| Order-4-infinite apeirogonal honeycomb | |
|---|---|
| Type | Regular honeycomb | 
| Schläfli symbols | {∞,4,∞} {∞,(4,∞,4)} | 
| Coxeter diagrams |               ↔       | 
| Cells | {∞,4}  | 
| Faces | {∞} | 
| Edge figure | {∞} | 
| Vertex figure |  {4,∞}  {(4,∞,4)} | 
| Dual | self-dual | 
| Coxeter group | [∞,4,∞] [∞,((4,∞,4))] | 
| Properties | Regular | 
In the geometry of hyperbolic 3-space, the order-4-infinite apeirogonal honeycomb is a regular space-filling tessellation (or honeycomb) with Schläfli symbol {∞,4,∞}. It has infinitely many order-4 apeirogonal tiling {∞,4} around each edge. All vertices are ultra-ideal (existing beyond the ideal boundary) with infinitely many hexagonal tilings existing around each vertex in an infinite-order square tiling vertex arrangement.
|  Poincaré disk model |  Ideal surface | 
It has a second construction as a uniform honeycomb, Schläfli symbol {∞,(4,∞,4)}, Coxeter diagram, 




 , with alternating types or colors of cells.
, with alternating types or colors of cells.
See also
References
- Coxeter, Regular Polytopes, 3rd. ed., Dover Publications, 1973. ISBN 0-486-61480-8. (Tables I and II: Regular polytopes and honeycombs, pp. 294–296)
- The Beauty of Geometry: Twelve Essays (1999), Dover Publications, LCCN 99-35678, ISBN 0-486-40919-8 (Chapter 10, Regular Honeycombs in Hyperbolic Space) Table III
- Jeffrey R. Weeks The Shape of Space, 2nd edition ISBN 0-8247-0709-5 (Chapters 16–17: Geometries on Three-manifolds I,II)
- George Maxwell, Sphere Packings and Hyperbolic Reflection Groups, JOURNAL OF ALGEBRA 79,78-97 (1982)
- Hao Chen, Jean-Philippe Labbé, Lorentzian Coxeter groups and Boyd-Maxwell ball packings, (2013)
- Visualizing Hyperbolic Honeycombs arXiv:1511.02851 Roice Nelson, Henry Segerman (2015)
External links
- John Baez, Visual insights: {5,4,3} Honeycomb (2014/08/01) {5,4,3} Honeycomb Meets Plane at Infinity (2014/08/14)
- Danny Calegari, Kleinian, a tool for visualizing Kleinian groups, Geometry and the Imagination 4 March 2014.