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.
Hurwitz's automorphisms theoremIn mathematics, Hurwitz's automorphisms theorem bounds the order of the group of automorphisms, via orientation-preserving conformal mappings, of a compact Riemann surface of genus g > 1, stating that the number of such automorphisms cannot exceed 84(g − 1). A group for which the maximum is achieved is called a Hurwitz group, and the corresponding Riemann surface a Hurwitz surface. Because compact Riemann surfaces are synonymous with non-singular complex projective algebraic curves, a Hurwitz surface can also be called a Hurwitz curve.
Quartique de Kleinthumb|La quartique de Klein est le quotient d'un pavage uniforme triangulaire d'ordre 7. En géométrie hyperbolique, la quartique de Klein, du nom du mathématicien allemand Felix Klein, est une surface de Riemann compacte de genre 3. Elle a le groupe d'automorphismes d'ordre le plus élevé possible parmi les surfaces de Riemann de genre 3, à savoir le groupe simple d'ordre 168. La quartique de Klein est en conséquence la de genre le plus bas possible. Surface de Bolza Surface de Macbeath Théorème de Stark-Hee
Heptagonal tilingIn 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. This tiling is topologically related as a part of sequence of regular polyhedra with Schläfli symbol {n,3}. 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.
Symbole de WythoffEn géométrie, un symbole de Wythoff est une notation courte, créée par le mathématicien Willem Abraham Wythoff, pour nommer les polyèdres réguliers et semi-réguliers utilisant une construction kaléidoscopique, en les représentant comme des pavages sur la surface d'une sphère, sur un plan euclidien ou un plan hyperbolique. Le symbole de Wythoff donne 3 nombres p,q,r et une barre verticale positionnelle (|) qui sépare les nombres avant et après elle. Chaque nombre représente l'ordre des miroirs à un sommet du triangle fondamental.
Schwarz triangleIn geometry, a Schwarz triangle, named after Hermann Schwarz, is a spherical triangle that can be used to tile a sphere (spherical tiling), possibly overlapping, through reflections in its edges. They were classified in . These can be defined more generally as tessellations of the sphere, the Euclidean plane, or the hyperbolic plane. Each Schwarz triangle on a sphere defines a finite group, while on the Euclidean or hyperbolic plane they define an infinite group.
Truncated order-7 triangular tilingIn geometry, the order-7 truncated triangular tiling, sometimes called the hyperbolic soccerball, is a semiregular tiling of the hyperbolic plane. There are two hexagons and one heptagon on each vertex, forming a pattern similar to a conventional soccer ball (truncated icosahedron) with heptagons in place of pentagons. It has Schläfli symbol of t{3,7}. This tiling is called a hyperbolic soccerball (football) for its similarity to the truncated icosahedron pattern used on soccer balls.
Snub (geometry)In geometry, a snub is an operation applied to a polyhedron. The term originates from Kepler's names of two Archimedean solids, for the snub cube (cubus simus) and snub dodecahedron (dodecaedron simum). In general, snubs have chiral symmetry with two forms: with clockwise or counterclockwise orientation. By Kepler's names, a snub can be seen as an expansion of a regular polyhedron: moving the faces apart, twisting them about their centers, adding new polygons centered on the original vertices, and adding pairs of triangles fitting between the original edges.
Uniform tilingIn geometry, a uniform tiling is a tessellation of the plane by regular polygon faces with the restriction of being vertex-transitive. Uniform tilings can exist in both the Euclidean plane and hyperbolic plane. Uniform tilings are related to the finite uniform polyhedra which can be considered uniform tilings of the sphere. Most uniform tilings can be made from a Wythoff construction starting with a symmetry group and a singular generator point inside of the fundamental domain.
Construction de WythoffEn géométrie, une construction de Wythoff, nommée en l'honneur du mathématicien Willem Abraham Wythoff, est une méthode pour construire un polyèdre uniforme ou un pavage plan. On l'appelle souvent construction kaléidoscopique de Wythoff. Elle repose sur le pavage d'une sphère, avec des triangles sphériques. Si trois miroirs sont placés de telle manière que leurs plans se coupent en un point unique, alors les miroirs entourent un triangle sphérique sur la surface d'une sphère quelconque centrée en ce point et par réflexions répétées, on obtient une multitude de copies du triangle.
