Pentellated 8-simplexes
8-simplex | Pentellated 8-simplex | Bipentitruncated 8-simplex |
Orthogonal projections in A8 Coxeter plane |
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In eight-dimensional geometry, a pentellated 8-simplex is a convex uniform 8-polytope with 5th order truncations of the regular 8-simplex.
There are two unique pentellations of the 8-simplex. Including truncations, cantellations, runcinations, and sterications, there are 32 more pentellations. These polytopes are a part of a family 135 uniform 8-polytopes with A8 symmetry. A8, [37] has order 9 factorial symmetry, or 362880. The bipentalled form is symmetrically ringed, doubling the symmetry order to 725760, and is represented the double-bracketed group [[37]]. The A8 Coxeter plane projection shows order [9] symmetry for the pentellated 8-simplex, while the bipentellated 8-simple is doubled to [18] symmetry.
Pentellated 8-simplex Edit
Pentellated 8-simplex | |
---|---|
Type | uniform 8-polytope |
Schläfli symbol | t0,5{3,3,3,3,3,3,3} |
Coxeter-Dynkin diagrams | |
7-faces | |
6-faces | |
5-faces | |
4-faces | |
Cells | |
Faces | |
Edges | 5040 |
Vertices | 504 |
Vertex figure | |
Coxeter group | A8, [37], order 362880 |
Properties | convex |
Coordinates Edit
The Cartesian coordinates of the vertices of the pentellated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,0,0,1,1,1,1,2). This construction is based on facets of the pentellated 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] |
Bipentellated 8-simplex Edit
Bipentellated 8-simplex | |
---|---|
Type | uniform 8-polytope |
Schläfli symbol | t1,6{3,3,3,3,3,3,3} |
Coxeter-Dynkin diagrams | |
7-faces | t0,5{3,3,3,3,3,3} |
6-faces | |
5-faces | |
4-faces | |
Cells | |
Faces | |
Edges | 7560 |
Vertices | 756 |
Vertex figure | |
Coxeter group | A8×2, [[37]], order 725760 |
Properties | convex, facet-transitive |
Coordinates Edit
The Cartesian coordinates of the vertices of the bipentellated 8-simplex can be most simply positioned in 9-space as permutations of (0,0,1,1,1,1,1,2,2). This construction is based on facets of the bipentellated 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
This polytope is one of 135 uniform 8-polytopes with A8 symmetry.
A8 polytopes | ||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
t0 | t1 | t2 | t3 | t01 | t02 | t12 | t03 | t13 | t23 | t04 | t14 | t24 | t34 | t05 |
t15 | t25 | t06 | t16 | t07 | t012 | t013 | t023 | t123 | t014 | t024 | t124 | t034 | t134 | t234 |
t015 | t025 | t125 | t035 | t135 | t235 | t045 | t145 | t016 | t026 | t126 | t036 | t136 | t046 | t056 |
t017 | t027 | t037 | t0123 | t0124 | t0134 | t0234 | t1234 | t0125 | t0135 | t0235 | t1235 | t0145 | t0245 | t1245 |
t0345 | t1345 | t2345 | t0126 | t0136 | t0236 | t1236 | t0146 | t0246 | t1246 | t0346 | t1346 | t0156 | t0256 | t1256 |
t0356 | t0456 | t0127 | t0137 | t0237 | t0147 | t0247 | t0347 | t0157 | t0257 | t0167 | t01234 | t01235 | t01245 | t01345 |
t02345 | t12345 | t01236 | t01246 | t01346 | t02346 | t12346 | t01256 | t01356 | t02356 | t12356 | t01456 | t02456 | t03456 | t01237 |
t01247 | t01347 | t02347 | t01257 | t01357 | t02357 | t01457 | t01267 | t01367 | t012345 | t012346 | t012356 | t012456 | t013456 | t023456 |
t123456 | t012347 | t012357 | t012457 | t013457 | t023457 | t012367 | t012467 | t013467 | t012567 | t0123456 | t0123457 | t0123467 | t0123567 | t01234567 |
Notes Edit
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, ISBN 978-0-471-01003-6 [1]
- (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)". x3o3o3o3o3x3o3o, o3x3o3o3o3o3x3o
External links Edit
- Multi-dimensional Glossary