affine set
71Commutative ring — In ring theory, a branch of abstract algebra, a commutative ring is a ring in which the multiplication operation is commutative. The study of commutative rings is called commutative algebra. Some specific kinds of commutative rings are given with …
72Homogeneous coordinates — In mathematics, homogeneous coordinates, introduced by August Ferdinand Möbius in his 1827 work Der barycentrische Calcul [ [http://www history.mcs.st andrews.ac.uk/Biographies/Mobius.html Mobius biography ] ] , allow affine transformations to be …
73Level of measurement — The levels of measurement , or scales of measure are expressions that typically refer to the theory of scale types developed by the psychologist Stanley Smith Stevens. Stevens proposed his theory in a 1946 Science article titled On the theory of… …
74Spectrum of a ring — In abstract algebra and algebraic geometry, the spectrum of a commutative ring R , denoted by Spec( R ), is defined to be the set of all proper prime ideals of R . It is commonly augmented with the Zariski topology and with a structure sheaf,… …
75Kac–Moody algebra — In mathematics, a Kac–Moody algebra is a Lie algebra, usually infinite dimensional, that can be defined by generators and relations through a generalized Cartan matrix. Kac–Moody algebras are named after Victor Kac and Robert Moody, who… …
76Convex optimization — Convex minimization, a subfield of optimization, studies the problem of minimizing convex functions over convex sets. Given a real vector space X together with a convex, real valued function defined on a convex subset of X, the problem is to find …
77Spacetime symmetries — refers to aspects of spacetime that can be described as exhibiting some form of symmetry. The role of symmetry in physics is important, for example, in simplifying solutions to many problems. Spacetime symmetries are used to simplify problems and …
78Algebraic space — In mathematics, an algebraic space is a generalization of the schemes of algebraic geometry introduced by Michael Artin for use in deformation theory.DefinitionAn algebraic space X comprises a schemeOne can always assume that U is an affine… …
79Euclidean vector — This article is about the vectors mainly used in physics and engineering to represent directed quantities. For mathematical vectors in general, see Vector (mathematics and physics). For other uses, see vector. Illustration of a vector …
80Cross-ratio — D is the harmonic conjugate of C with respect to A and B In geometry, the cross ratio, also called double ratio and anharmonic ratio, is a special number associated with an ordered quadruple of collinear points, particularly points on a… …
