Search results
Results From The WOW.Com Content Network
Free product. In mathematics, specifically group theory, the free product is an operation that takes two groups G and H and constructs a new group G ∗ H. The result contains both G and H as subgroups, is generated by the elements of these subgroups, and is the “ universal ” group having these properties, in the sense that any two ...
The free group FS is defined to be the group of all reduced words in S, with concatenation of words (followed by reduction if necessary) as group operation. The identity is the empty word. A reduced word is called cyclically reduced if its first and last letter are not inverse to each other.
A normal form for a free product of groups is a representation or choice of a reduced sequence for each element in the free product . Normal Form Theorem for Free Product of Groups. Consider the free product of two groups and . Then the following two equivalent statements hold. (1) If , where is a reduced sequence, then in.
t. e. In mathematics, specifically in group theory, the direct product is an operation that takes two groups G and H and constructs a new group, usually denoted G × H. This operation is the group-theoretic analogue of the Cartesian product of sets and is one of several important notions of direct product in mathematics.
The Nielsen–Schreier theorem is a non-abelian analogue of an older result of Richard Dedekind, that every subgroup of a free abelian group is free abelian. [3] Jakob Nielsen ( 1921) originally proved a restricted form of the theorem, stating that any finitely-generated subgroup of a free group is free. His proof involves performing a sequence ...
That is, the fundamental group of X is the free product of the fundamental groups of U 1 and U 2 with amalgamation of (,). [ 1 ] Usually the morphisms induced by inclusion in this theorem are not themselves injective , and the more precise version of the statement is in terms of pushouts of groups .
In the mathematical field of group theory, the Kurosh subgroup theorem describes the algebraic structure of subgroups of free products of groups. The theorem was obtained by Alexander Kurosh, a Russian mathematician, in 1934. [1] Informally, the theorem says that every subgroup of a free product is itself a free product of a free group and of ...
In mathematics, a product of groups usually refers to a direct product of groups, but may also mean: semidirect product. Product of group subsets. wreath product. free product. central product. Category: Mathematics disambiguation pages.