Английская Википедия:Heptagonal tiling

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Шаблон:Short description Шаблон:Uniform hyperbolic tiles db In geometry, a heptagonal tiling is a regular tiling of the hyperbolic plane. It is represented by Schläfli symbol of {7,3}, having three regular heptagons around each vertex.

Images

Файл:PavageDemiPlanPoincare.svg
Poincaré half-plane model
Файл:PavageHypPoincare2.svg
Poincaré disk model
Файл:PavageKleinBeltrami.svg
Beltrami-Klein model

Related polyhedra and tilings

This tiling is topologically related as a part of sequence of regular polyhedra with Schläfli symbol {n,3}. Шаблон:Order-3 tiling table

From a Wythoff construction there are eight hyperbolic uniform tilings that can be based from the regular heptagonal tiling.

Drawing the tiles colored as red on the original faces, yellow at the original vertices, and blue along the original edges, there are 8 forms. Шаблон:Heptagonal tiling table

Hurwitz surfaces

Файл:3-7 kisrhombille.svg
The symmetry group of the heptagonal tiling has fundamental domain the (2,3,7) Schwarz triangle, which yields this tiling.

Шаблон:See The symmetry group of the tiling is the (2,3,7) triangle group, and a fundamental domain for this action is the (2,3,7) Schwarz triangle. This is the smallest hyperbolic Schwarz triangle, and thus, by the proof of Hurwitz's automorphisms theorem, the tiling is the universal tiling that covers all Hurwitz surfaces (the Riemann surfaces with maximal symmetry group), giving them a tiling by heptagons whose symmetry group equals their automorphism group as Riemann surfaces. The smallest Hurwitz surface is the Klein quartic (genus 3, automorphism group of order 168), and the induced tiling has 24 heptagons, meeting at 56 vertices.

The dual order-7 triangular tiling has the same symmetry group, and thus yields triangulations of Hurwitz surfaces.

See also

Шаблон:Commonscat

References

Шаблон:Reflist Шаблон:Refbegin

Шаблон:Refend

External links

Шаблон:Tessellation