Truncated 8-simplexes
8-simplex |
Truncated 8-simplex |
Rectified 8-simplex |
Quadritruncated 8-simplex |
Tritruncated 8-simplex |
Bitruncated 8-simplex |
| Orthogonal projections in A8 Coxeter plane | ||
|---|---|---|
In eight-dimensional geometry, a truncated 8-simplex is a convex uniform 8-polytope, being a truncation of the regular 8-simplex.
There are four unique degrees of truncation. Vertices of the truncation 8-simplex are located as pairs on the edge of the 8-simplex. Vertices of the bitruncated 8-simplex are located on the triangular faces of the 8-simplex. Vertices of the tritruncated 8-simplex are located inside the tetrahedral cells of the 8-simplex.
Truncated 8-simplex
[edit]| Truncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope |
| Schläfli symbol | t{37} |
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 288 |
| Vertices | 72 |
| Vertex figure | ( )v{3,3,3,3,3} |
| Coxeter group | A8, [37], order 362880 |
| Properties | convex |
Alternate names
[edit]- Truncated enneazetton (Acronym: tene) (Jonathan Bowers)[1]
Coordinates
[edit]The Cartesian coordinates of the vertices of the truncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,0,0,1,2). This construction is based on facets of the truncated 9-orthoplex.
Images
[edit]| Ak Coxeter plane | A8 | A7 | A6 | A5 |
|---|---|---|---|---|
| Graph | ||||
| Dihedral symmetry | [9] | [8] | [7] | [6] |
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ||||
| Dihedral symmetry | [5] | [4] | [3] |
Bitruncated 8-simplex
[edit]| Bitruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope |
| Schläfli symbol | 2t{37} |
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 1008 |
| Vertices | 252 |
| Vertex figure | { }v{3,3,3,3} |
| Coxeter group | A8, [37], order 362880 |
| Properties | convex |
Alternate names
[edit]- Bitruncated enneazetton (Acronym: batene) (Jonathan Bowers)[2]
Coordinates
[edit]The Cartesian coordinates of the vertices of the bitruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,0,1,2,2). This construction is based on facets of the bitruncated 9-orthoplex.
Images
[edit]| Ak Coxeter plane | A8 | A7 | A6 | A5 |
|---|---|---|---|---|
| Graph | ||||
| Dihedral symmetry | [9] | [8] | [7] | [6] |
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ||||
| Dihedral symmetry | [5] | [4] | [3] |
Tritruncated 8-simplex
[edit]| tritruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope |
| Schläfli symbol | 3t{37} |
| Coxeter-Dynkin diagrams | |
| 7-faces | |
| 6-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 2016 |
| Vertices | 504 |
| Vertex figure | {3}v{3,3,3} |
| Coxeter group | A8, [37], order 362880 |
| Properties | convex |
Alternate names
[edit]- Tritruncated enneazetton (Acronym: tatene) (Jonathan Bowers)[3]
Coordinates
[edit]The Cartesian coordinates of the vertices of the tritruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,0,1,2,2,2). This construction is based on facets of the tritruncated 9-orthoplex.
Images
[edit]| Ak Coxeter plane | A8 | A7 | A6 | A5 |
|---|---|---|---|---|
| Graph | ||||
| Dihedral symmetry | [9] | [8] | [7] | [6] |
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ||||
| Dihedral symmetry | [5] | [4] | [3] |
Quadritruncated 8-simplex
[edit]| Quadritruncated 8-simplex | |
|---|---|
| Type | uniform 8-polytope |
| Schläfli symbol | 4t{37} |
| Coxeter-Dynkin diagrams | or |
| 6-faces | 18 3t{3,3,3,3,3,3} |
| 7-faces | |
| 5-faces | |
| 4-faces | |
| Cells | |
| Faces | |
| Edges | 2520 |
| Vertices | 630 |
| Vertex figure | {3,3}v{3,3} |
| Coxeter group | A8, [[37]], order 725760 |
| Properties | convex, isotopic |
The quadritruncated 8-simplex an isotopic polytope, constructed from 18 tritruncated 7-simplex facets.
Alternate names
[edit]- Octadecazetton (18-facetted 8-polytope) (Acronym: be) (Jonathan Bowers)[4]
Coordinates
[edit]The Cartesian coordinates of the vertices of the quadritruncated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,1,2,2,2,2). This construction is based on facets of the quadritruncated 9-orthoplex.
Images
[edit]| Ak Coxeter plane | A8 | A7 | A6 | A5 |
|---|---|---|---|---|
| Graph | ||||
| Dihedral symmetry | [[9]] = [18] | [8] | [[7]] = [14] | [6] |
| Ak Coxeter plane | A4 | A3 | A2 | |
| Graph | ||||
| Dihedral symmetry | [[5]] = [10] | [4] | [[3]] = [6] |
Related polytopes
[edit]| Dim. | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|
| Name Coxeter |
Hexagon t{3} = {6} |
Octahedron r{3,3} = {31,1} = {3,4} |
Decachoron 2t{33} |
Dodecateron 2r{34} = {32,2} |
Tetradecapeton 3t{35} |
Hexadecaexon 3r{36} = {33,3} |
Octadecazetton 4t{37} |
| Images | |||||||
| Vertex figure | ( )∨( ) | { }×{ } |
{ }∨{ } |
{3}×{3} |
{3}∨{3} |
{3,3}×{3,3} | {3,3}∨{3,3} |
| Facets | {3} |
t{3,3} |
r{3,3,3} |
2t{3,3,3,3} |
2r{3,3,3,3,3} |
3t{3,3,3,3,3,3} | |
| As intersecting dual simplexes |
The four presented polytopes are in the family of 135 uniform 8-polytopes with A8 symmetry.
Notes
[edit]- ^ Klitzing, (x3x3o3o3o3o3o3o - tene).
- ^ Klitzing, (o3x3x3o3o3o3o3o - batene).
- ^ Klitzing, (o3o3x3x3o3o3o3o - tatene)
- ^ Klitzing, (o3o3o3x3x3o3o3o - be).
References
[edit]- H.S.M. Coxeter:
- H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973
- Kaleidoscopes: Selected Writings of H.S.M. Coxeter, edited by F. Arthur Sherk, Peter McMullen, Anthony C. Thompson, Asia Ivic Weiss, Wiley-Interscience Publication, 1995, wiley.com, ISBN 978-0-471-01003-6
- (Paper 22) H.S.M. Coxeter, Regular and Semi-Regular Polytopes I, [Math. Zeit. 46 (1940) 380–407, MR 2,10]
- (Paper 23) H.S.M. Coxeter, Regular and Semi-Regular Polytopes II, [Math. Zeit. 188 (1985) 559–591]
- (Paper 24) H.S.M. Coxeter, Regular and Semi-Regular Polytopes III, [Math. Zeit. 200 (1988) 3–45]
- Norman Johnson Uniform Polytopes, Manuscript (1991)
- N.W. Johnson: The Theory of Uniform Polytopes and Honeycombs, Ph.D.
- Klitzing, Richard. "8D uniform polytopes (polyzetta) with acronyms". x3x3o3o3o3o3o3o - tene, o3x3x3o3o3o3o3o - batene, o3o3x3x3o3o3o3o - tatene, o3o3o3x3x3o3o3o - be