Rectified 5-simplexes#Intersection of two 5-simplices

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5-simplex
{{CDD|node_1|3|node|3|node|3|node|3|node}}

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Rectified 5-simplex
{{CDD|node|3|node_1|3|node|3|node|3|node}}

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Birectified 5-simplex
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colspan=3|Orthogonal projections in A5 Coxeter plane

In five-dimensional geometry, a rectified 5-simplex is a convex uniform 5-polytope, being a rectification of the regular 5-simplex.

There are three unique degrees of rectifications, including the zeroth, the 5-simplex itself. Vertices of the rectified 5-simplex are located at the edge-centers of the 5-simplex. Vertices of the birectified 5-simplex are located in the triangular face centers of the 5-simplex.

Rectified 5-simplex

{{Uniform polyteron db|Uniform polyteron stat table|rix}}

In five-dimensional geometry, a rectified 5-simplex is a uniform 5-polytope with 15 vertices, 60 edges, 80 triangular faces, 45 cells (30 tetrahedral, and 15 octahedral), and 12 4-faces (6 5-cell and 6 rectified 5-cells). It is also called 03,1 for its branching Coxeter-Dynkin diagram, shown as {{CDD|node_1|split1|nodes|3a|nodea|3a|nodea}}.

E. L. Elte identified it in 1912 as a semiregular polytope, labeling it as S{{supsub|1|5}}.

= Alternate names =

  • Rectified hexateron (Acronym: rix) (Jonathan Bowers)

= Coordinates =

The vertices of the rectified 5-simplex can be more simply positioned on a hyperplane in 6-space as permutations of (0,0,0,0,1,1) or (0,0,1,1,1,1). These construction can be seen as facets of the rectified 6-orthoplex or birectified 6-cube respectively.

= As a configuration =

This configuration matrix represents the rectified 5-simplex. The rows and columns correspond to vertices, edges, faces, cells and 4-faces. The diagonal numbers say how many of each element occur in the whole rectified 5-simplex. 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

The diagonal f-vector numbers are derived through the Wythoff construction, dividing the full group order of a subgroup order by removing one mirror at a time.{{KlitzingPolytopes|../incmats/rix.htm|o3x3o3o3o - rix}}

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!A5

{{CDD|node|3|node_1|3|node|3|node|3|node}}k-facefkf0f1colspan=2|f2colspan=2|f3colspan=2|f4k-figurenotes
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|A3A1

{{CDD|node|2|node_x|2|node|3|node|3|node}}( )

! f0

|BGCOLOR="#ffe0e0"|15

84126842{3,3}×{ }A5/A3A1 = 6!/4!/2 = 15
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|A2A1

{{CDD|node_x|2|node_1|2|node_x|2|node|3|node}}{ }

! f1

2BGCOLOR="#ffffe0"|60133331{3}∨( )A5/A2A1 = 6!/3!/2 = 60
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|A2A2

{{CDD|node|3|node_1|2|node_x|2|node|3|node}}r{3}

!rowspan=2|f2

33BGCOLOR="#e0ffe0"|20BGCOLOR="#e0ffe0"|*3030{3}A5/A2A2 = 6!/3!/3! =20
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|A2A1

{{CDD|node_x|2|node_1|3|node|2|node_x|2|node}}{3}33BGCOLOR="#e0ffe0"|*BGCOLOR="#e0ffe0"|601221{ }×( )A5/A2A1 = 6!/3!/2 = 60
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|A3A1

{{CDD|node|3|node_1|3|node|2|node_x|2|node}}r{3,3}

!rowspan=2|f3

61244BGCOLOR="#e0ffff"|15BGCOLOR="#e0ffff"|*20rowspan=2|{ }A5/A3A1 = 6!/4!/2 = 15
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|A3

{{CDD|node_x|2|node_1|3|node|3|node|2|node_x}}{3,3}4604BGCOLOR="#e0ffff"|*BGCOLOR="#e0ffff"|3011A5/A3 = 6!/4! = 30
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|A4

{{CDD|node|3|node_1|3|node|3|node|2|node_x}}r{3,3,3}

!rowspan=2|f4

1030102055BGCOLOR="#e0e0ff"|6BGCOLOR="#e0e0ff"|*rowspan=2|( )A5/A4 = 6!/5! = 6
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|A4

{{CDD|node_x|2|node_1|3|node|3|node|3|node}}{3,3,3}51001005BGCOLOR="#e0e0ff"|*BGCOLOR="#e0e0ff"|6A5/A4 = 6!/5! = 6

= Images =

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|+ Stereographic projection

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Stereographic projection of spherical form

{{5-simplex Coxeter plane graphs|t1|100}}

= Related polytopes=

The rectified 5-simplex, 031, is second in a dimensional series of uniform polytopes, expressed by Coxeter as 13k series. The fifth figure is a Euclidean honeycomb, 331, and the final is a noncompact hyperbolic honeycomb, 431. Each progressive uniform polytope is constructed from the previous as its vertex figure.

{{k 31 polytopes}}

Birectified 5-simplex

{{Uniform polyteron db|Uniform polyteron stat table|dot}}

The birectified 5-simplex is isotopic, with all 12 of its facets as rectified 5-cells. It has 20 vertices, 90 edges, 120 triangular faces, 60 cells (30 tetrahedral, and 30 octahedral).

E. L. Elte identified it in 1912 as a semiregular polytope, labeling it as S{{supsub|2|5}}.

It is also called 02,2 for its branching Coxeter-Dynkin diagram, shown as {{CDD|node_1|split1|nodes|3ab|nodes}}. It is seen in the vertex figure of the 6-dimensional 122, {{CDD|node_1|3|node|split1|nodes|3ab|nodes}}.

= Alternate names =

  • Birectified hexateron
  • dodecateron (Acronym: dot) (For 12-facetted polyteron) (Jonathan Bowers)

= Construction =

The elements of the regular polytopes can be expressed in a configuration matrix. Rows and columns reference vertices, edges, faces, and cells, with diagonal element their counts (f-vectors). The nondiagonal elements represent the number of row elements are incident to the column element.Coxeter, Regular Polytopes, sec 1.8 ConfigurationsCoxeter, Complex Regular Polytopes, p.117

The diagonal f-vector numbers are derived through the Wythoff construction, dividing the full group order of a subgroup order by removing one mirror at a time.{{KlitzingPolytopes|../incmats/dot.htm|o3o3x3o3o - dot}}

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!A5

{{CDD|node|3|node|3|node_1|3|node|3|node}}k-facefkf0f1colspan=2|f2colspan=3|f3colspan=2|f4k-figurenotes
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|A2A2

{{CDD|node|3|node|2|node_x|2|node|3|node}}( )

! f0

|BGCOLOR="#ffe0e0"|20

99939333{3}×{3}A5/A2A2 = 6!/3!/3! = 20
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|A1A1A1

{{CDD|node|2|node_x|2|node_1|2|node_x|2|node}}{ }

! f1

2BGCOLOR="#ffffe0"|902214122{ }∨{ }A5/A1A1A1 = 6!/2/2/2 = 90
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|A2A1

{{CDD|node_x|2|node|3|node_1|2|node_x|2|node}}rowspan=2|{3}

!rowspan=2|f2

33BGCOLOR="#e0ffe0"|60BGCOLOR="#e0ffe0"|*12021rowspan=2|{ }∨( )rowspan=2| A5/A2A1 = 6!/3!/2 = 60
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|A2A1

{{CDD|node|2|node_x|2|node_1|3|node|2|node_x}}33BGCOLOR="#e0ffe0"|*BGCOLOR="#e0ffe0"|6002112
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|A3A1

{{CDD|node|3|node|3|node_1|2|node_x|2|node}}{3,3}

!rowspan=3|f3

4640BGCOLOR="#e0ffff"|15BGCOLOR="#e0ffff"|*BGCOLOR="#e0ffff"|*20rowspan=3|{ }A5/A3A1 = 6!/4!/2 = 15
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|A3

{{CDD|node_x|2|node|3|node_1|3|node|2|node_x}}r{3,3}61244BGCOLOR="#e0ffff"|*BGCOLOR="#e0ffff"|30BGCOLOR="#e0ffff"|*11A5/A3 = 6!/4! = 30
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|A3A1

{{CDD|node|2|node_x|2|node_1|3|node|3|node}}{3,3}4604BGCOLOR="#e0ffff"|*BGCOLOR="#e0ffff"|*BGCOLOR="#e0ffff"|1502A5/A3A1 = 6!/4!/2 = 15
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|A4

{{CDD|node|3|node|3|node_1|3|node|2|node_x}}rowspan=2|r{3,3,3}

!rowspan=2|f4

10302010550BGCOLOR="#e0e0ff"|6BGCOLOR="#e0e0ff"|*rowspan=2|( )rowspan=2|A5/A4 = 6!/5! = 6
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|A4

{{CDD|node_x|2|node|3|node_1|3|node|3|node}}10301020055BGCOLOR="#e0e0ff"|*BGCOLOR="#e0e0ff"|6

= Images =

The A5 projection has an identical appearance to Metatron's Cube.{{cite book |last= Melchizedek |first= Drunvalo |title= The Ancient Secret of the Flower of Life|publisher= Light Technology Publishing | date=1999 |volume=1 }} p.160 Figure 6-12

{{5-simplex2 Coxeter plane graphs|t2|100}}

= Intersection of two 5-simplices =

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|+ Stereographic projection

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The birectified 5-simplex is the intersection of two regular 5-simplexes in dual configuration. The vertices of a birectification exist at the center of the faces of the original polytope(s). This intersection is analogous to the 3D stellated octahedron, seen as a compound of two regular tetrahedra and intersected in a central octahedron, while that is a first rectification where vertices are at the center of the original edges.

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Dual 5-simplexes (red and blue), and their birectified 5-simplex intersection in green, viewed in A5 and A4 Coxeter planes. The simplexes overlap in the A5 projection and are drawn in magenta.

It is also the intersection of a 6-cube with the hyperplane that bisects the 6-cube's long diagonal orthogonally. In this sense it is the 5-dimensional analog of the regular hexagon, octahedron, and bitruncated 5-cell. This characterization yields simple coordinates for the vertices of a birectified 5-simplex in 6-space: the 20 distinct permutations of (1,1,1,−1,−1,−1).

The vertices of the birectified 5-simplex can also be positioned on a hyperplane in 6-space as permutations of (0,0,0,1,1,1). This construction can be seen as facets of the birectified 6-orthoplex.

= Related polytopes=

== k_22 polytopes ==

The birectified 5-simplex, 022, is second in a dimensional series of uniform polytopes, expressed by Coxeter as k22 series. The birectified 5-simplex is the vertex figure for the third, the 122. The fourth figure is a Euclidean honeycomb, 222, and the final is a noncompact hyperbolic honeycomb, 322. Each progressive uniform polytope is constructed from the previous as its vertex figure.

{{k 22 polytopes}}

== Isotopics polytopes==

{{Isotopic uniform simplex polytopes}}

Related uniform 5-polytopes

This polytope is the vertex figure of the 6-demicube, and the edge figure of the uniform 231 polytope.

It is also one of 19 uniform polytera based on the [3,3,3,3] Coxeter group, all shown here in A5 Coxeter plane orthographic projections. (Vertices are colored by projection overlap order, red, orange, yellow, green, cyan, blue, purple having progressively more vertices)

{{Hexateron family}}

References

{{reflist}}

  • 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}} [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.
  • {{KlitzingPolytopes|polytera.htm|5D|uniform polytopes (polytera)}} o3x3o3o3o - rix, o3o3x3o3o - dot