infinite subgroup
81Whitehead torsion — In mathematics, Whitehead torsion is an invariant of an h cobordism in a Whitehead group, that is important in simple homotopy theory and surgery theory. It is named for J. H. C. Whitehead.Whitehead torsionSuppose that W is an h cobordism from M… …
82Kuiper's theorem — In mathematics, Kuiper s theorem (after Nicolaas Kuiper) is a result on the topology of operators on an infinite dimensional, complex Hilbert space H. It states that the space GL(H) of invertible bounded endomorphisms H is such that all maps …
83Representation theory of SL2(R) — In mathematics, the main results concerning irreducible unitary representations of the Lie group SL2(R) are due to Gelfand and Naimark (1946), V. Bargmann (1947), and Harish Chandra (1952). Structure of the complexified Lie algebra We choose a… …
84Composition series — In abstract algebra, a composition series provides a way to break up an algebraic structure, such as a group or a module, into simple pieces. The need for considering composition series in the context of modules arises from the fact that many… …
85Outer automorphism group — In mathematics, the outer automorphism group of a group G is the quotient Aut(G) / Inn(G), where Aut(G) is the automorphism group of G and Inn(G) is the subgroup consisting of inner automorphisms. The outer automorphism group is usually …
86Torsion (algebra) — In abstract algebra, the term torsion refers to a number of concepts related to elements of finite order in groups and to the failure of modules to be free. Definition Let G be a group. An element g of G is called a torsion element if g has… …
87Lattice of subgroups — In mathematics, the lattice of subgroups of a group G is the lattice whose elements are the subgroups of G, with the partial order relation being set inclusion.In this lattice, the join of two subgroups is the subgroup generated by their union,… …
88Group ring — This page discusses the algebraic group ring of a discrete group; for the case of a topological group see group algebra, and for a general group see Group Hopf algebra. In algebra, a group ring is a free module and at the same time a ring,… …
89Orbifold notation — In geometry, orbifold notation (or orbifold signature) is a system, invented by William Thurston and popularized by the mathematician John Conway, for representing types of symmetry groups in two dimensional spaces of constant curvature. The… …
90Mass in general relativity — General relativity Introduction Mathematical formulation Resources Fundamental concepts …
