Truncated triapeirogonal tilingIn geometry, the truncated triapeirogonal tiling is a uniform tiling of the hyperbolic plane with a Schläfli symbol of tr{∞,3}. The dual of this tiling represents the fundamental domains of [∞,3], *∞32 symmetry. There are 3 small index subgroup constructed from [∞,3] by mirror removal and alternation. In these images fundamental domains are alternately colored black and white, and mirrors exist on the boundaries between colors. A special index 4 reflective subgroup, is [(∞,∞,3)], (∞∞3), and its direct subgroup [(∞,∞,3)]+, (∞∞3), and semidirect subgroup [(∞,∞,3+)], (3∞).
Uniform tilings in hyperbolic planeIn hyperbolic geometry, a uniform hyperbolic tiling (or regular, quasiregular or semiregular hyperbolic tiling) is an edge-to-edge filling of the hyperbolic plane which has regular polygons as faces and is vertex-transitive (transitive on its vertices, isogonal, i.e. there is an isometry mapping any vertex onto any other). It follows that all vertices are congruent, and the tiling has a high degree of rotational and translational symmetry.
Diagramme de Coxeter-DynkinEn géométrie, un diagramme de Coxeter-Dynkin est un graphe représentant un ensemble relationnel de miroirs (ou d'hyperplans de réflexion) dans l'espace pour une construction kaléidoscopique. En tant que graphe lui-même, le diagramme représente les groupes de Coxeter, chaque nœud du graphe représente un miroir (facette du domaine) et chaque branche du graphe représente l'ordre de l'angle diédral entre deux miroirs (sur une arête du domaine). En plus, les graphes ont des anneaux (cercles) autour des nœuds pour les miroirs actifs représentant un polytope précis.
Orbifold notationIn geometry, orbifold notation (or orbifold signature) is a system, invented by the mathematician William Thurston and promoted by John Conway, for representing types of symmetry groups in two-dimensional spaces of constant curvature. The advantage of the notation is that it describes these groups in a way which indicates many of the groups' properties: in particular, it follows William Thurston in describing the orbifold obtained by taking the quotient of Euclidean space by the group under consideration.
