isomorphic extension
51Direct product of groups — Concepts in group theory category of groups subgroups, normal subgroups group homomorphisms, kernel, image, quotient direct product, direct sum semidirect product, wreath product …
52Semidirect product — In mathematics, especially in the area of abstract algebra known as group theory, a semidirect product is a particular way in which a group can be put together from two subgroups, one of which is a normal subgroup. A semidirect product is a… …
53Approximately finite dimensional C*-algebra — In C* algebras, an approximately finite dimensional, or AF, C* algebra is one that is the inductive limit of a sequence of finite dimensional C* algebras. Approximate finite dimensionality was first defined and described combinatorially by… …
54Galois theory — In mathematics, more specifically in abstract algebra, Galois theory, named after Évariste Galois, provides a connection between field theory and group theory. Using Galois theory, certain problems in field theory can be reduced to group theory,… …
55Groupoid — dablink|This article is about groupoids in category theory. For the algebraic structure with a single binary operation see magma (algebra). In mathematics, especially in category theory and homotopy theory, a groupoid is a simultaneous… …
56General linear group — Group theory Group theory …
57Class field theory — In mathematics, class field theory is a major branch of algebraic number theory that studies abelian extensions of number fields. Most of the central results in this area were proved in the period between 1900 and 1950. The theory takes its name… …
58Polynomial ring — In mathematics, especially in the field of abstract algebra, a polynomial ring is a ring formed from the set of polynomials in one or more variables with coefficients in another ring. Polynomial rings have influenced much of mathematics, from the …
59Banach algebra — In mathematics, especially functional analysis, a Banach algebra, named after Stefan Banach, is an associative algebra A over the real or complex numbers which at the same time is also a Banach space. The algebra multiplication and the Banach… …
60C*-algebra — C* algebras (pronounced C star ) are an important area of research in functional analysis, a branch of mathematics. The prototypical example of a C* algebra is a complex algebra A of linear operators on a complex Hilbert space with two additional …
