10-simplex explained

bgcolor=#e7dcc3 colspan=2Regular hendecaxennon
(10-simplex)
bgcolor=#ffffff align=center colspan=2
Orthogonal projection
inside Petrie polygon
TypeRegular 10-polytope
Familysimplex
Schläfli symbol
Coxeter-Dynkin diagram
9-faces11 9-simplex
8-faces55 8-simplex
7-faces165 7-simplex
6-faces330 6-simplex
5-faces462 5-simplex
4-faces462 5-cell
Cells330 tetrahedron
Faces165 triangle
Edges55
Vertices11
Vertex figure9-simplex
Petrie polygonhendecagon
Coxeter groupA10 [3,3,3,3,3,3,3,3,3]
DualSelf-dual polytopeSelf-dual
Propertiesconvex
In geometry, a 10-simplex is a self-dual regular 10-polytope. It has 11 vertices, 55 edges, 165 triangle faces, 330 tetrahedral cells, 462 5-cell 4-faces, 462 5-simplex 5-faces, 330 6-simplex 6-faces, 165 7-simplex 7-faces, 55 8-simplex 8-faces, and 11 9-simplex 9-faces. Its dihedral angle is cos−1(1/10), or approximately 84.26°.

It can also be called a hendecaxennon, or hendeca-10-tope, as an 11-facetted polytope in 10-dimensions. The name hendecaxennon is derived from hendeca for 11 facets in Greek and -xenn (variation of ennea for nine), having 9-dimensional facets, and -on.

Coordinates

The Cartesian coordinates of the vertices of an origin-centered regular 10-simplex having edge length 2 are:

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28},\sqrt{1/21},\sqrt{1/15},\sqrt{1/10},\sqrt{1/6},\sqrt{1/3},\pm1\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28},\sqrt{1/21},\sqrt{1/15},\sqrt{1/10},\sqrt{1/6}, -2\sqrt{1/3}, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28},\sqrt{1/21},\sqrt{1/15},\sqrt{1/10}, -\sqrt{3/2}, 0, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28},\sqrt{1/21},\sqrt{1/15}, -2\sqrt{2/5}, 0, 0, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28},\sqrt{1/21}, -\sqrt{5/3}, 0, 0, 0, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6,\sqrt{1/28}, -\sqrt{12/7}, 0, 0, 0, 0, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, 1/6, -\sqrt{7/4}, 0, 0, 0, 0, 0, 0\right)

\left(\sqrt{1/55},\sqrt{1/45}, -4/3, 0, 0, 0, 0, 0, 0, 0\right)

\left(\sqrt{1/55}, -3\sqrt{1/5}, 0, 0, 0, 0, 0, 0, 0, 0\right)

\left(-\sqrt{20/11}, 0, 0, 0, 0, 0, 0, 0, 0, 0\right)

More simply, the vertices of the 10-simplex can be positioned in 11-space as permutations of (0,0,0,0,0,0,0,0,0,0,1). This construction is based on facets of the 11-orthoplex.

Related polytopes

The 2-skeleton of the 10-simplex is topologically related to the 11-cell abstract regular polychoron which has the same 11 vertices, 55 edges, but only 1/3 the faces (55).

References

External links