quotient geometry
61Polyèdre de coordination — La notion de polyèdre de coordination est utilisée en cristallographie et en chimie pour décrire l environnement d une espèce chimique par ses ligands dans un cristal ou un complexe. Il s agit du polyèdre formé par les ligands autour de l espèce… …
62Angle — This article is about angles in geometry. For other uses, see Angle (disambiguation). Oblique angle redirects here. For the cinematographic technique, see Dutch angle. ∠, the angle symbol In geometry, an angle is the figure formed by two rays… …
63Bass–Serre theory — is a part of the mathematical subject of group theory that deals with analyzing the algebraic structure of groups acting by automorphisms on simplicial trees. The theory relates group actions on trees with decomposing groups as iterated… …
64Arithmetic — tables for children, Lausanne, 1835 Arithmetic or arithmetics (from the Greek word ἀριθμός, arithmos “number”) is the oldest and most elementary branch of mathematics, used b …
65Topological group — Concepts in group theory category of groups subgroups, normal subgroups group homomorphisms, kernel, image, quotient direct product, direct sum semidirect product, wreath product …
66Algebraic variety — This article is about algebraic varieties. For the term a variety of algebras , and an explanation of the difference between a variety of algebras and an algebraic variety, see variety (universal algebra). The twisted cubic is a projective… …
67Differential of a function — For other uses of differential in mathematics, see differential (mathematics). In calculus, the differential represents the principal part of the change in a function y = ƒ(x) with respect to changes in the independent variable. The… …
68Spherical 3-manifold — In mathematics, a spherical 3 manifold M is a 3 manifold of the form M = S3 / Γ where Γ is a finite subgroup of SO(4) acting freely by rotations on the 3 sphere S3. All such manifolds are prime, orientable, and closed. Spherical 3 manifolds are… …
69Mathematics of Sudoku — The class of Sudoku puzzles consists of a partially completed row column grid of cells partitioned into N regions each of size N cells, to be filled in using a prescribed set of N distinct symbols (typically the numbers {1, ..., N}), so that each …
70Bogomolov–Miyaoka–Yau inequality — In mathematics, the Bogomolov–Miyaoka–Yau inequality is the inequality between Chern numbers of compact complex surfaces of general type. Its major interest is the way it restricts the possible topological types of the underlying real 4 manifold …
