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



 , with alternating types or colors of cells. In Coxeter notation the half symmetry is [6,5,6,1+] = [6,((5,3,5))].
, with alternating types or colors of cells. In Coxeter notation the half symmetry is [6,5,6,1+] = [6,((5,3,5))].
Order-5-7 heptagonal honeycomb
    
| Order-5-7 hexagonal honeycomb | |
|---|---|
| Type | Regular honeycomb | 
| Schläfli symbols | {7,5,7} | 
| Coxeter diagrams |        | 
| Cells | {7,5}  | 
| Faces | {6} | 
| Edge figure | {6} | 
| Vertex figure | {5,7}  | 
| Dual | self-dual | 
| Coxeter group | [7,5,7] | 
| Properties | Regular | 
In the geometry of hyperbolic 3-space, the order-5-7 heptagonal honeycomb (or 7,5,7 honeycomb) is a regular space-filling tessellation (or honeycomb) with Schläfli symbol {7,5,7}. It has seven order-5 heptagonal tilings, {7,5}, around each edge. All vertices are ultra-ideal (existing beyond the ideal boundary) with infinitely many heptagonal tilings existing around each vertex in an order-7 pentagonal tiling vertex arrangement.
|  Ideal surface | 
Order-5-infinite apeirogonal honeycomb
    
| Order-5-infinite apeirogonal honeycomb | |
|---|---|
| Type | Regular honeycomb | 
| Schläfli symbols | {∞,5,∞} {∞,(5,∞,5)} | 
| Coxeter diagrams |               ↔       | 
| Cells | {∞,5}  | 
| Faces | {∞} | 
| Edge figure | {∞} | 
| Vertex figure |  {5,∞}  {(5,∞,5)} | 
| Dual | self-dual | 
| Coxeter group | [∞,5,∞] [∞,((5,∞,5))] | 
| Properties | Regular | 
In the geometry of hyperbolic 3-space, the order-5-infinite apeirogonal honeycomb (or ∞,5,∞ honeycomb) is a regular space-filling tessellation (or honeycomb) with Schläfli symbol {∞,5,∞}. It has infinitely many order-5 apeirogonal tilings {∞,5} around each edge. All vertices are ultra-ideal (existing beyond the ideal boundary) with infinitely many order-5 apeirogonal tilings existing around each vertex in an infinite-order pentagonal tiling vertex arrangement.
|  Poincaré disk model |  Ideal surface | 
It has a second construction as a uniform honeycomb, Schläfli symbol {∞,(5,∞,5)}, 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: {7,3,3} Honeycomb (2014/08/01) {7,3,3} Honeycomb Meets Plane at Infinity (2014/08/14)
- Danny Calegari, Kleinian, a tool for visualizing Kleinian groups, Geometry and the Imagination 4 March 2014.