Truncated tetraoctagonal tiling

Truncated tetraoctagonal tiling

Poincaré disk model of the hyperbolic plane
TypeHyperbolic uniform tiling
Vertex figure4.8.16
Schläfli symboltr{8,4}
Wythoff symbol2 8 4 |
Coxeter diagram
Symmetry group[8,4], (*842)
DualOrder-4-8 kisrhombille tiling
PropertiesVertex-transitive

In geometry, the truncated tetraoctagonal tiling is a semiregular tiling of the hyperbolic plane. There are one square, one octagon, and one hexakaidecagon on each vertex. It has Schläfli symbol of tr{8,4}.

Dual tiling

The dual tiling is called an order-4-8 kisrhombille tiling, made as a complete bisection of the order-4 octagonal tiling, here with triangles are shown with alternating colors. This tiling represents the fundamental triangular domains of [8,4] (*842) symmetry.

Symmetry

Truncated tetraoctagonal tiling with *842, , mirror lines

There are 15 subgroups constructed from [8,4] by mirror removal and alternation. Mirrors can be removed if its branch orders are all even, and cuts neighboring branch orders in half. Removing two mirrors leaves a half-order gyration point where the removed mirrors met. In these images fundamental domains are alternately colored black and white, and mirrors exist on the boundaries between colors. The subgroup index-8 group, [1+,8,1+,4,1+] (4242) is the commutator subgroup of [8,4].

A larger subgroup is constructed as [8,4*], index 8, as [8,4+], (4*4) with gyration points removed, becomes (*4444) or (*44), and another [8*,4], index 16 as [8+,4], (8*2) with gyration points removed as (*22222222) or (*28). And their direct subgroups [8,4*]+, [8*,4]+, subgroup indices 16 and 32 respectively, can be given in orbifold notation as (4444) and (22222222).

Small index subgroups of [8,4] (*842)
Index 1 2 4
Diagram
Coxeter [8,4]
=
[1+,8,4]
=
[8,4,1+]
= =
[8,1+,4]
=
[1+,8,4,1+]
=
[8+,4+]
Orbifold *842 *444 *882 *4222 *4242 42×
Semidirect subgroups
Diagram
Coxeter [8,4+]
[8+,4]
[(8,4,2+)]
[8,1+,4,1+]
= =
= =
[1+,8,1+,4]
= =
= =
Orbifold 4*4 8*2 2*42 2*44 4*22
Direct subgroups
Index 2 4 8
Diagram
Coxeter [8,4]+
=
[8,4+]+
=
[8+,4]+
=
[8,1+,4]+
=
[8+,4+]+ = [1+,8,1+,4,1+]
= = =
Orbifold 842 444 882 4222 4242
Radical subgroups
Index 8 16 32
Diagram
Coxeter [8,4*]
=
[8*,4]
[8,4*]+
=
[8*,4]+
Orbifold *4444 *22222222 4444 22222222

Related polyhedra and tilings

From a Wythoff construction there are fourteen hyperbolic uniform tilings that can be based from the regular order-4 octagonal tiling.

Drawing the tiles colored as red on the original faces, yellow at the original vertices, and blue along the original edges, there are 7 forms with full [8,4] symmetry, and 7 with subsymmetry.

Uniform octagonal/square tilings
[8,4], (*842)
(with [8,8] (*882), [(4,4,4)] (*444) , [,4,] (*4222) index 2 subsymmetries)
(And [(,4,,4)] (*4242) index 4 subsymmetry)

=

=
=

=

=
=

=


=


=
=



=
{8,4} t{8,4}
r{8,4} 2t{8,4}=t{4,8} 2r{8,4}={4,8} rr{8,4} tr{8,4}
Uniform duals
V84 V4.16.16 V(4.8)2 V8.8.8 V48 V4.4.4.8 V4.8.16
Alternations
[1+,8,4]
(*444)
[8+,4]
(8*2)
[8,1+,4]
(*4222)
[8,4+]
(4*4)
[8,4,1+]
(*882)
[(8,4,2+)]
(2*42)
[8,4]+
(842)

=

=

=

=

=

=
h{8,4} s{8,4} hr{8,4} s{4,8} h{4,8} hrr{8,4} sr{8,4}
Alternation duals
V(4.4)4 V3.(3.8)2 V(4.4.4)2 V(3.4)3 V88 V4.44 V3.3.4.3.8
Dimensional family of omnitruncated polyhedra and tilings: 4.8.2n
Symmetry
*n42
[n,4]
Spherical Euclidean Compact hyperbolic Paracompact
*242
[2,4]
D4h
*342
[3,4]
Oh
*442
[4,4]
P4m
*542
[5,4]
*642
[6,4]
*742
[7,4]
*842
[8,4]...
*42
[,4]
Omnitruncated
figure

4.8.4

4.8.6

4.8.8

4.8.10

4.8.12

4.8.14

4.8.16

4.8.
Coxeter
Schläfli

tr{2,4}

tr{3,4}

tr{4,4}

tr{5,4}

tr{6,4}

tr{7,4}

tr{8,4}

tr{,4}
Omnitruncated
duals

V4.8.4

V4.8.6

V4.8.8

V4.8.10

V4.8.12

V4.8.14

V4.8.16

V4.8.
Coxeter
Dimensional family of omnitruncated polyhedra and tilings: 4.2n.2n
Symmetry
*nn2
[n,n]
Spherical Euclidean Compact hyperbolic Paracompact
*222
[2,2]
D2h
*332
[3,3]
Td
*442
[4,4]
P4m
*552
[5,5]
*662
[6,6]
*772
[7,7]
*882
[8,8]...
*2
[,]
Figure
4.4.4

4.6.6

4.8.8

4.10.10

4.12.12

4.14.14

4.16.16

4..
Coxeter
Schläfli

tr{2,2}

tr{3,3}

tr{4,4}

tr{5,5}

tr{6,6}

tr{7,7}

tr{8,8}

tr{,}
Dual
V4.4.4

V4.6.6

V4.8.8

V4.10.10

V4.12.12

V4.14.14

V4.16.16

V4..
Coxeter

See also

Wikimedia Commons has media related to Uniform tiling 4-8-16.

References

External links