free subgroup
21Von Neumann conjecture — In mathematics, the von Neumann conjecture stated that a topological group G is not amenable if and only if G contains a subgroup that is a free group on two generators. The conjecture was disproved in 1980.In the 1920s, during his groundbreaking …
22Core (group) — In group theory, a branch of mathematics, a core is any of certain special normal subgroups of a group. The two most common types are the normal core of a subgroup and the p core of a group. Contents 1 The normal core 1.1 Definition 1.2… …
23Elliptic curve — In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O . An elliptic curve is in fact an abelian variety mdash; that is, it has a multiplication defined algebraically with… …
24Tits alternative — In mathematics, the Tits alternative, named for Jacques Tits, is an important theorem about the structure of finitely generated linear groups. It states that every such group is either virtually solvable (i.e. has a solvable subgroup of finite… …
25Slender group — In mathematics, a slender group is a torsion free abelian group that is small in a sense that is made precise in the definition below. Definition Let ZN denote the Baer–Specker group, that is, the group of all integer sequences, with termwise… …
26Jacques Tits — (born August 12, 1930 in Uccle) is a French (and formerly Belgian) mathematician. He has written and cowritten a large number of papers on a number of subjects, principally group theory.His academic career includes professorships at the Free… …
27Abelian group — For other uses, see Abelian (disambiguation). Abelian group is also an archaic name for the symplectic group Concepts in group theory category of groups subgroups, normal subgroups group homomorphisms, kernel, image, quotient direct product,… …
28John R. Stallings — John Robert Stallings is a mathematician known for his seminal contributions to geometric group theory and 3 manifold topology. Stallings is a Professor Emeritus in the Department of Mathematics and the University of California at Berkeley. [… …
29Nielsen–Schreier theorem — In group theory, a branch of mathematics, the Nielsen–Schreier theorem is the statement that every subgroup of a free group is itself free.[1][2][3] It is named after Jakob Nielsen and Otto Schreier. Contents …
30Direct 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 …
