321 | 231 | 132 | |||
Rectified 321 | birectified 321 | ||||
Rectified 231 | Rectified 132 | ||||
Orthogonal projections in E7 Coxeter plane |
---|
In 7-dimensional geometry, 231 is a uniform polytope, constructed from the E7 group.
Its Coxeter symbol is 231, describing its bifurcating Coxeter-Dynkin diagram, with a single ring on the end of the 2-node branch.
The rectified 231 is constructed by points at the mid-edges of the 231.
These polytopes are part of a family of 127 (or 27−1) convex uniform polytopes in 7-dimensions, made of uniform polytope facets and vertex figures, defined by all permutations of rings in this Coxeter-Dynkin diagram: .
Gosset 231 polytope | |
---|---|
Type | Uniform 7-polytope |
Family | 2k1 polytope |
Schläfli symbol | {3,3,33,1} |
Coxeter symbol | 231 |
Coxeter diagram | |
6-faces | 632: 56 221 576 {35} |
5-faces | 4788: 756 211 4032 {34} |
4-faces | 16128: 4032 201 12096 {33} |
Cells | 20160 {32} |
Faces | 10080 {3} |
Edges | 2016 |
Vertices | 126 |
Vertex figure | 131 |
Petrie polygon | Octadecagon |
Coxeter group | E7, [33,2,1] |
Properties | convex |
The 231 is composed of 126 vertices, 2016 edges, 10080 faces (Triangles), 20160 cells (tetrahedra), 16128 4-faces (3-simplexes), 4788 5-faces (756 pentacrosses, and 4032 5-simplexes), 632 6-faces (576 6-simplexes and 56 221). Its vertex figure is a 6-demicube. Its 126 vertices represent the root vectors of the simple Lie group E7.
This polytope is the vertex figure for a uniform tessellation of 7-dimensional space, 331 .
It is created by a Wythoff construction upon a set of 7 hyperplane mirrors in 7-dimensional space.
The facet information can be extracted from its Coxeter-Dynkin diagram, .
Removing the node on the short branch leaves the 6-simplex. There are 576 of these facets. These facets are centered on the locations of the vertices of the 321 polytope, .
Removing the node on the end of the 3-length branch leaves the 221. There are 56 of these facets. These facets are centered on the locations of the vertices of the 132 polytope, .
The vertex figure is determined by removing the ringed node and ringing the neighboring node. This makes the 6-demicube, 131, .
Seen in a configuration matrix, the element counts can be derived by mirror removal and ratios of Coxeter group orders. [3]
E7 | k-face | fk | f0 | f1 | f2 | f3 | f4 | f5 | f6 | k-figures | notes | ||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
D6 | ( ) | f0 | 126 | 32 | 240 | 640 | 160 | 480 | 60 | 192 | 12 | 32 | 6-demicube | E7/D6 = 72x8!/32/6! = 126 | |
A5A1 | { } | f1 | 2 | 2016 | 15 | 60 | 20 | 60 | 15 | 30 | 6 | 6 | rectified 5-simplex | E7/A5A1 = 72x8!/6!/2 = 2016 | |
A3A2A1 | {3} | f2 | 3 | 3 | 10080 | 8 | 4 | 12 | 6 | 8 | 4 | 2 | tetrahedral prism | E7/A3A2A1 = 72x8!/4!/3!/2 = 10080 | |
A3A2 | {3,3} | f3 | 4 | 6 | 4 | 20160 | 1 | 3 | 3 | 3 | 3 | 1 | tetrahedron | E7/A3A2 = 72x8!/4!/3! = 20160 | |
A4A2 | {3,3,3} | f4 | 5 | 10 | 10 | 5 | 4032 | * | 3 | 0 | 3 | 0 | {3} | E7/A4A2 = 72x8!/5!/3! = 4032 | |
A4A1 | 5 | 10 | 10 | 5 | * | 12096 | 1 | 2 | 2 | 1 | Isosceles triangle | E7/A4A1 = 72x8!/5!/2 = 12096 | |||
D5A1 | {3,3,3,4} | f5 | 10 | 40 | 80 | 80 | 16 | 16 | 756 | * | 2 | 0 | { } | E7/D5A1 = 72x8!/32/5! = 756 | |
A5 | {3,3,3,3} | 6 | 15 | 20 | 15 | 0 | 6 | * | 4032 | 1 | 1 | E7/A5 = 72x8!/6! = 72*8*7 = 4032 | |||
E6 | {3,3,32,1} | f6 | 27 | 216 | 720 | 1080 | 216 | 432 | 27 | 72 | 56 | * | ( ) | E7/E6 = 72x8!/72x6! = 8*7 = 56 | |
A6 | {3,3,3,3,3} | 7 | 21 | 35 | 35 | 0 | 21 | 0 | 7 | * | 576 | E7/A6 = 72x8!/7! = 72×8 = 576 |
E7 | E6 / F4 | B6 / A6 |
---|---|---|
[18] | [12] | [7x2] |
A5 | D7 / B6 | D6 / B5 |
[6] | [12/2] | [10] |
D5 / B4 / A4 | D4 / B3 / A2 / G2 | D3 / B2 / A3 |
[8] | [6] | [4] |
2k1 figures in n dimensions | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Space | Finite | Euclidean | Hyperbolic | ||||||||
n | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |||
Coxeter group | E3=A2A1 | E4=A4 | E5=D5 | E6 | E7 | E8 | E9 = = E8+ | E10 = = E8++ | |||
Coxeter diagram | |||||||||||
Symmetry | [3−1,2,1] | [30,2,1] | [[31,2,1]] | [32,2,1] | [33,2,1] | [34,2,1] | [35,2,1] | [36,2,1] | |||
Order | 12 | 120 | 384 | 51,840 | 2,903,040 | 696,729,600 | ∞ | ||||
Graph | - | - | |||||||||
Name | 2−1,1 | 201 | 211 | 221 | 231 | 241 | 251 | 261 |
Rectified 231 polytope | |
---|---|
Type | Uniform 7-polytope |
Family | 2k1 polytope |
Schläfli symbol | {3,3,33,1} |
Coxeter symbol | t1(231) |
Coxeter diagram | |
6-faces | 758 |
5-faces | 10332 |
4-faces | 47880 |
Cells | 100800 |
Faces | 90720 |
Edges | 30240 |
Vertices | 2016 |
Vertex figure | 6-demicube |
Petrie polygon | Octadecagon |
Coxeter group | E7, [33,2,1] |
Properties | convex |
The rectified 231 is a rectification of the 231 polytope, creating new vertices on the center of edge of the 231.
It is created by a Wythoff construction upon a set of 7 hyperplane mirrors in 7-dimensional space.
The facet information can be extracted from its Coxeter-Dynkin diagram, .
Removing the node on the short branch leaves the rectified 6-simplex, .
Removing the node on the end of the 2-length branch leaves the, 6-demicube, .
Removing the node on the end of the 3-length branch leaves the rectified 221, .
The vertex figure is determined by removing the ringed node and ringing the neighboring node.
E7 | E6 / F4 | B6 / A6 |
---|---|---|
[18] | [12] | [7x2] |
A5 | D7 / B6 | D6 / B5 |
[6] | [12/2] | [10] |
D5 / B4 / A4 | D4 / B3 / A2 / G2 | D3 / B2 / A3 |
[8] | [6] | [4] |
In seven-dimensional geometry, a 7-polytope is a polytope contained by 6-polytope facets. Each 5-polytope ridge being shared by exactly two 6-polytope facets.
In five-dimensional geometry, a demipenteract or 5-demicube is a semiregular 5-polytope, constructed from a 5-hypercube (penteract) with alternated vertices removed.
In geometry, the Gosset–Elte figures, named by Coxeter after Thorold Gosset and E. L. Elte, are a group of uniform polytopes which are not regular, generated by a Wythoff construction with mirrors all related by order-2 and order-3 dihedral angles. They can be seen as one-end-ringed Coxeter–Dynkin diagrams.
In five-dimensional geometry, a rectified 5-simplex is a convex uniform 5-polytope, being a rectification of the regular 5-simplex.
In 6-dimensional geometry, the 122 polytope is a uniform polytope, constructed from the E6 group. It was first published in E. L. Elte's 1912 listing of semiregular polytopes, named as V72 (for its 72 vertices).
In 7-dimensional geometry, 132 is a uniform polytope, constructed from the E7 group.
In 8-dimensional geometry, the 142 is a uniform 8-polytope, constructed within the symmetry of the E8 group.
In 8-dimensional geometry, the 241 is a uniform 8-polytope, constructed within the symmetry of the E8 group.
In 6-dimensional geometry, the 221 polytope is a uniform 6-polytope, constructed within the symmetry of the E6 group. It was discovered by Thorold Gosset, published in his 1900 paper. He called it an 6-ic semi-regular figure. It is also called the Schläfli polytope.
In 7-dimensional geometry, the 321 polytope is a uniform 7-polytope, constructed within the symmetry of the E7 group. It was discovered by Thorold Gosset, published in his 1900 paper. He called it an 7-ic semi-regular figure.
In 8-dimensional geometry, the 421 is a semiregular uniform 8-polytope, constructed within the symmetry of the E8 group. It was discovered by Thorold Gosset, published in his 1900 paper. He called it an 8-ic semi-regular figure.
In geometry, the 152 honeycomb is a uniform tessellation of 8-dimensional Euclidean space. It contains 142 and 151 facets, in a birectified 8-simplex vertex figure. It is the final figure in the 1k2 polytope family.
In 8-dimensional geometry, the 251 honeycomb is a space-filling uniform tessellation. It is composed of 241 polytope and 8-simplex facets arranged in an 8-demicube vertex figure. It is the final figure in the 2k1 family.
In geometry, the 222 honeycomb is a uniform tessellation of the six-dimensional Euclidean space. It can be represented by the Schläfli symbol {3,3,32,2}. It is constructed from 221 facets and has a 122 vertex figure, with 54 221 polytopes around every vertex.
In 7-dimensional geometry, the 331 honeycomb is a uniform honeycomb, also given by Schläfli symbol {3,3,3,33,1} and is composed of 321 and 7-simplex facets, with 56 and 576 of them respectively around each vertex.
In 7-dimensional geometry, 133 is a uniform honeycomb, also given by Schläfli symbol {3,33,3}, and is composed of 132 facets.
In six-dimensional geometry, a rectified 6-simplex is a convex uniform 6-polytope, being a rectification of the regular 6-simplex.
In seven-dimensional geometry, a rectified 7-simplex is a convex uniform 7-polytope, being a rectification of the regular 7-simplex.
In eight-dimensional geometry, a rectified 8-simplex is a convex uniform 8-polytope, being a rectification of the regular 8-simplex.
In geometry, an E9 honeycomb is a tessellation of uniform polytopes in hyperbolic 9-dimensional space. , also (E10) is a paracompact hyperbolic group, so either facets or vertex figures will not be bounded.