7-cube
{{Short description|7-dimensional hypercube}}
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!bgcolor=#e7dcc3 colspan=2|7-cube | |
bgcolor=#ffffff align=center colspan=2|280px Orthogonal projection inside Petrie polygon The central orange vertex is doubled | |
bgcolor=#e7dcc3|Type | Regular 7-polytope |
bgcolor=#e7dcc3|Family | hypercube |
bgcolor=#e7dcc3|Schläfli symbol | {4,35} |
bgcolor=#e7dcc3|Coxeter-Dynkin diagrams | {{CDD|node_1|4|node|3|node|3|node|3|node|3|node|3|node}} {{CDD|node_1|2c|node_1|4|node|3|node|3|node|3|node|3|node |
{{CDD|node_1|2c|node_1|2c|node_1|4|node|3|node|3|node|3|node|}}
{{CDD|node_1|2c|node_1|2c|node_1|2c|node_1|4|node|3|node|3|node|}}
{{CDD|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1|4|node|3|node|}}
{{CDD|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1|4|node|}}
{{CDD|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1|2c|node_1}}
|-
|bgcolor=#e7dcc3|6-faces||14 {4,34} 25px
|-
|bgcolor=#e7dcc3|5-faces||84 {4,33} 25px
|-
|bgcolor=#e7dcc3|4-faces||280 {4,3,3} 25px
|-
|bgcolor=#e7dcc3|Cells||560 {4,3} 25px
|-
|bgcolor=#e7dcc3|Faces||672 {4} 25px
|-
|bgcolor=#e7dcc3|Edges||448
|-
|bgcolor=#e7dcc3|Vertices||128
|-
|bgcolor=#e7dcc3|Vertex figure||6-simplex 25px
|-
|bgcolor=#e7dcc3|Petrie polygon||tetradecagon
|-
|bgcolor=#e7dcc3|Coxeter group||C7, [35,4]
|-
|bgcolor=#e7dcc3|Dual||7-orthoplex
|-
|bgcolor=#e7dcc3|Properties||convex, Hanner polytope
|}
In geometry, a 7-cube is a seven-dimensional hypercube with 128 vertices, 448 edges, 672 square faces, 560 cubic cells, 280 tesseract 4-faces, 84 penteract 5-faces, and 14 hexeract 6-faces.
It can be named by its Schläfli symbol {4,35}, being composed of 3 6-cubes around each 5-face. It can be called a hepteract, a portmanteau of tesseract (the 4-cube) and hepta for seven (dimensions) in Greek. It can also be called a regular tetradeca-7-tope or tetradecaexon, being a 7 dimensional polytope constructed from 14 regular facets.
Related polytopes
The 7-cube is 7th in a series of hypercube:
{{Hypercube polytopes}}
The dual of a 7-cube is called a 7-orthoplex, and is a part of the infinite family of cross-polytopes.
Applying an alternation operation, deleting alternating vertices of the hepteract, creates another uniform polytope, called a demihepteract, (part of an infinite family called demihypercubes), which has 14 demihexeractic and 64 6-simplex 6-faces.
As a configuration
This configuration matrix represents the 7-cube. The rows and columns correspond to vertices, edges, faces, cells, 4-faces, 5-faces and 6-faces. The diagonal numbers say how many of each element occur in the whole 7-cube. The nondiagonal numbers say how many of the column's element occur in or at the row's element.Coxeter, Regular Polytopes, sec 1.8 ConfigurationsCoxeter, Complex Regular Polytopes, p.117
128 & 7 & 21 & 35 & 35 & 21 & 7
\\ 2 & 448 & 6 & 15 & 20 & 15 & 6
\\ 4 & 4 & 672 & 5 & 10 & 10 & 5
\\ 8 & 12 & 6 & 560 & 4 & 6 & 4
\\ 16 & 32 & 24 & 8 & 280 & 3 & 3
\\ 32 & 80 & 80 & 40 & 10 & 84 & 2
\\ 64 & 192 & 240 & 160 & 60 & 12 & 14
\end{matrix}\end{bmatrix}
Cartesian coordinates
Cartesian coordinates for the vertices of a hepteract centered at the origin and edge length 2 are
: (±1,±1,±1,±1,±1,±1,±1)
while the interior of the same consists of all points (x0, x1, x2, x3, x4, x5, x6) with -1 < xi < 1.
{{-}}
Projections
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{{7-cube Coxeter plane graphs|t0|150}}
References
- H.S.M. Coxeter:
- Coxeter, Regular Polytopes, (3rd edition, 1973), Dover edition, {{ISBN|0-486-61480-8}}, p. 296, Table I (iii): Regular Polytopes, three regular polytopes in n-dimensions (n≥5)
- H.S.M. Coxeter, Regular Polytopes, 3rd Edition, Dover New York, 1973, p. 296, Table I (iii): Regular Polytopes, three regular polytopes in n-dimensions (n≥5)
- 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}} [http://www.wiley.com/WileyCDA/WileyTitle/productCd-0471010030.html]
- (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. (1966)
- {{KlitzingPolytopes|polyexa.htm|7D uniform polytopes (polyexa)|o3o3o3o3o3o4x - hept}}
External links
- {{MathWorld|title=Hypercube|urlname=Hypercube}}
- {{MathWorld|title=Hypercube graph|urlname=HypercubeGraph}}
- {{GlossaryForHyperspace | anchor=Measure | title=Measure polytope }}
- [http://tetraspace.alkaline.org/glossary.htm Multi-dimensional Glossary: hypercube] Garrett Jones
- [http://www.4d-screen.de/related-space/4d-space/7d-cube.htm Rotation of 7D-Cube] www.4d-screen.de
{{Polytopes}}