5-cell honeycomb: Difference between revisions

 

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|bgcolor=#e7dcc3|Vertex figure||[[File:Omnitruncated 4-simplex honeycomb verf.png|80px]]<BR>Irr. [[5-cell]]

|bgcolor=#e7dcc3|Vertex figure||[[File:Omnitruncated 4-simplex honeycomb verf.png|80px]]<BR>Irr. [[5-cell]]

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|bgcolor=#e7dcc3|[[Coxeter notation|Symmetry]]||<math>{\tilde{A}}_4</math>×10, <nowiki>[5[</nowiki>3^[5]]]

|bgcolor=#e7dcc3|[[Coxeter notation|Symmetry]]||<math>{\tilde{A}}_4</math>×10, <nowiki>[5[</nowiki>3^[5]]]

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|bgcolor=#e7dcc3|Properties||[[vertex-transitive]], [[cell-transitive]]

|bgcolor=#e7dcc3|Properties||[[vertex-transitive]], [[cell-transitive]]

Geometric figure

In four-dimensional Euclidean geometry, the 4-simplex honeycomb, 5-cell honeycomb or pentachoric-dispentachoric honeycomb is a space-filling tessellation honeycomb. It is composed of 5-cells and rectified 5-cells facets in a ratio of 1:1.

Cells of the vertex figure are ten tetrahedrons and 20 triangular prisms, corresponding to the ten 5-cells and 20 rectified 5-cells that meet at each vertex. All the vertices lie in parallel realms in which they form alternated cubic honeycombs, the tetrahedra being either tops of the rectified 5-cell or the bases of the 5-cell, and the octahedra being the bottoms of the rectified 5-cell.^[1]

• Cyclopentachoric tetracomb
• Pentachoric-dispentachoric tetracomb

The 5-cell honeycomb can be projected into the 2-dimensional square tiling by a geometric folding operation that maps two pairs of mirrors into each other, sharing the same vertex arrangement:

Two different aperiodic tilings with 5-fold symmetry can be obtained by projecting two-dimensional slices of the honeycomb: the Penrose tiling composed of rhombi, and the Tübingen triangle tiling composed of isosceles triangles.^[2]

The vertex arrangement of the 5-cell honeycomb is called the A4 lattice, or 4-simplex lattice. The 20 vertices of its vertex figure, the runcinated 5-cell represent the 20 roots of the ${\displaystyle {\tilde {A}}_{4}}$ Coxeter group.^[3][4] It is the 4-dimensional case of a simplectic honeycomb.

The A^*
₄ lattice^[5] is the union of five A₄ lattices, and is the dual to the omnitruncated 5-simplex honeycomb, and therefore the Voronoi cell of this lattice is an omnitruncated 5-cell

∪ ∪ ∪ ∪ = dual of

The tops of the 5-cells in this honeycomb adjoin the bases of the 5-cells, and vice versa, in adjacent laminae (or layers); but alternating laminae may be inverted so that the tops of the rectified 5-cells adjoin the tops of the rectified 5-cells and the bases of the 5-cells adjoin the bases of other 5-cells. This inversion results in another non-Wythoffian uniform convex honeycomb. Octahedral prisms and tetrahedral prisms may be inserted in between alternated laminae as well, resulting in two more non-Wythoffian elongated uniform honeycombs.^[6]

This honeycomb is one of seven unique uniform honeycombs^[7] constructed by the ${\displaystyle {\tilde {A}}_{4}}$ Coxeter group. The symmetry can be multiplied by the symmetry of rings in the Coxeter–Dynkin diagrams:

The rectified 4-simplex honeycomb or rectified 5-cell honeycomb is a space-filling tessellation honeycomb.

• small cyclorhombated pentachoric tetracomb
• small prismatodispentachoric tetracomb

Cyclotruncated 5-cell honeycomb
(No image)
Type	Uniform 4-honeycomb
Family	Truncated simplectic honeycomb
Schläfli symbol	t0,1{3[5]}
Coxeter diagram
4-face types	{3,3,3} t{3,3,3} 2t{3,3,3}
Cell types	{3,3} t{3,3}
Face types	Triangle {3} Hexagon {6}
Vertex figure	Tetrahedral antiprism [3,4,2+], order 48
Symmetry	${\displaystyle {\tilde {A}}_{4}}$×2 [3[5]]
Properties	vertex-transitive

The cyclotruncated 4-simplex honeycomb or cyclotruncated 5-cell honeycomb is a space-filling tessellation honeycomb. It can also be seen as a birectified 5-cell honeycomb.

It is composed of 5-cells, truncated 5-cells, and bitruncated 5-cells facets in a ratio of 2:2:1. Its vertex figure is a tetrahedral antiprism, with 2 regular tetrahedron, 8 triangular pyramid, and 6 tetragonal disphenoid cells, defining 2 5-cell, 8 truncated 5-cell, and 6 bitruncated 5-cell facets around a vertex.

It can be constructed as five sets of parallel hyperplanes that divide space into two half-spaces. The 3-space hyperplanes contain quarter cubic honeycombs as a collection facets.^[8]

• Cyclotruncated pentachoric tetracomb
• Small truncated-pentachoric tetracomb

The truncated 4-simplex honeycomb or truncated 5-cell honeycomb is a space-filling tessellation honeycomb. It can also be called a cyclocantitruncated 5-cell honeycomb.

• Great cyclorhombated pentachoric tetracomb
• Great truncated-pentachoric tetracomb

The cantellated 4-simplex honeycomb or cantellated 5-cell honeycomb is a space-filling tessellation honeycomb. It can also be called a cycloruncitruncated 5-cell honeycomb.

• Cycloprismatorhombated pentachoric tetracomb
• Great prismatodispentachoric tetracomb

Bitruncated 5-cell honeycomb
(No image)
Type	Uniform 4-honeycomb
Schläfli symbol	t0,1,2,3{3[5]} or 2t{3[5]}
Coxeter diagram
4-face types	t0,1,3{33} t0,1,2{33} t0,1,2,3{33}
Cell types	Cuboctahedron Truncated octahedron Truncated tetrahedron Hexagonal prism Triangular prism
Vertex figure	tilted rectangular duopyramid
Symmetry	${\displaystyle {\tilde {A}}_{4}}$×2 [3[5]]
Properties	vertex-transitive

The bitruncated 4-simplex honeycomb or bitruncated 5-cell honeycomb is a space-filling tessellation honeycomb. It can also be called a cycloruncicantitruncated 5-cell honeycomb.

• Great cycloprismated pentachoric tetracomb
• Grand prismatodispentachoric tetracomb

Omnitruncated 4-simplex honeycomb
(No image)
Type	Uniform 4-honeycomb
Family	Omnitruncated simplectic honeycomb
Schläfli symbol	t0,1,2,3,4{3[5]} or tr{3[5]}
Coxeter diagram
4-face types	t0,1,2,3{3,3,3}
Cell types	t0,1,2{3,3} {6}x{}
Face types	{4} {6}
Vertex figure	Irr. 5-cell
Symmetry	${\displaystyle {\tilde {A}}_{4}}$×10, [5[3[5]]]
Properties	vertex-transitive, cell-transitive

The omnitruncated 4-simplex honeycomb or omnitruncated 5-cell honeycomb is a space-filling tessellation honeycomb. It can also be seen as a cyclosteriruncicantitruncated 5-cell honeycomb.

It is composed entirely of omnitruncated 5-cell (omnitruncated 4-simplex) facets.

Coxeter calls this Hinton’s honeycomb after C. H. Hinton, who described it in his book The Fourth Dimension in 1906.^[9]

The facets of all omnitruncated simplectic honeycombs are called permutohedra and can be positioned in n+1 space with integral coordinates, permutations of the whole numbers (0,1,…,n).

• Omnitruncated cyclopentachoric tetracomb
• Great-prismatodecachoric tetracomb

The A^*
₄ lattice is the union of five A₄ lattices, and is the dual to the omnitruncated 5-cell honeycomb, and therefore the Voronoi cell of this lattice is an omnitruncated 5-cell.^[10]

∪ ∪ ∪ ∪ = dual of

This honeycomb can be alternated, creating omnisnub 5-cells with irregular 5-cells created at the deleted vertices. Although it is not uniform, the 5-cells have a symmetry of order 10.

Regular and uniform honeycombs in 4-space:

• Norman Johnson Uniform Polytopes, Manuscript (1991)
• 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] (1.9 Uniform space-fillings)
  • (Paper 24) H.S.M. Coxeter, Regular and Semi-Regular Polytopes III, [Math. Zeit. 200 (1988) 3-45]
• George Olshevsky, Uniform Panoploid Tetracombs, Manuscript (2006) (Complete list of 11 convex uniform tilings, 28 convex uniform honeycombs, and 143 convex uniform tetracombs) Model 134
• Klitzing, Richard. “4D Euclidean tesselations”., x3o3o3o3o3*a – cypit – O134, x3x3x3x3x3*a – otcypit – 135, x3x3x3o3o3*a – gocyropit – O137, x3x3o3x3o3*a – cypropit – O138, x3x3x3x3o3*a – gocypapit – O139, x3x3x3x3x3*a – otcypit – 140
• Affine Coxeter group Wa(A4), Quaternions, and Decagonal Quasicrystals, Mehmet Koca, Nazife O. Koca, Ramazan Koc (2013) arXiv:1209.1878