FACTOID # 39: The eight most developed countries all speak Germanic languages.
 
 Home   Encyclopedia   Statistics   Countries A-Z   Flags   Maps   Education   Forum   FAQ   About 
 
WHAT'S NEW
RECENT ARTICLES
More Recent Articles »
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Center (group theory)

In abstract algebra, the centre of a group G is the set Z(G) of all elements in G which commute with all the elements of G. Specifically, Abstract algebra is the field of mathematics concerned with the study of algebraic structures such as groups, rings and fields. ... In mathematics, a group is a set, together with a binary operation, such as multiplication or addition, satisfying certain axioms, detailed below. ... In mathematics, especially abstract algebra, a binary operation * on a set S is commutative if x * y = y * x for all x and y in S. Otherwise * is noncommutative. ...

Z(G) = {zG | gz = zg for all gG}

Note that Z(G) is a subgroup of G — if x and y are in Z(G), then for each g in G, (xy)g = x(yg) = x(gy) = (xg)y = (gx)y = g(xy) so xy is in Z(G) as well. A similar argument applies to inverses. In group theory, given a group G under a binary operation *, we say that some subset H of G is a subgroup of G if H also forms a group under the operation *. More precisely, H is a subgroup of G if the restriction of * to H is a group...


Moreover, Z(G) is an abelian subgroup of G, a normal subgroup of G, and even a strictly characteristic subgroup of G, but not always fully characteristic. In mathematics, an abelian group, also called a commutative group, is a group such that for all a and b in G. In other words, the order of elements in a product doesnt matter. ... In mathematics, a normal subgroup N of a group G is a subgroup invariant under conjugation; that is, for each element n in N and each g in G, the element g−1ng is still in N. The statement N is a normal subgroup of G is written: . There are... In abstract algebra, a characteristic subgroup of a group G is a subgroup H of G invariant under each automorphism of G. This means that if f : G → G is a group automorphism (a bijective homomorphism from the group G to itself), then for every x in H we have...


The centre of G is all of G iff G is an abelian group. At the other extreme, a group is said to be centreless if Z(G) is trivial. IFF, Iff or iff can stand for: Interchange File Format - a computer file format introduced by Electronic Arts Identification, friend or foe - a radio based identification system utilizing transponders iff - the mathematics concept if and only if International Flavors and Fragrances - a company producing flavors and fragrances International Freedom Foundation...


Consider the map f: G → Aut(G) to the automorphism group of G defined by f(g)(h) = ghg−1. The kernel of this map is the centre of G and the image is called the inner automorphism group of G, denoted Inn(G). By the first isomorphism theorem G/Z(G) cong Inn(G). In mathematics, an automorphism is an isomorphism from a mathematical object to itself. ... In the various branches of mathematics that fall under the heading of abstract algebra, the kernel of a homomorphism measures the degree to which the homomorphism fails to be injective. ... In abstract algebra, an inner automorphism of a group is a function f : G -> G defined by f(x) = axa-1     for all x in G; where the conjugation is often denoted exponentially by xa. ... In mathematics, the isomorphism theorems are three theorems, applied widely in the realm of universal algebra, stating the existence of certain natural isomorphisms. ...


Examples

In mathematics, the orthogonal group of degree n over a field F (written as O(n,F)) is the group of n-by-n orthogonal matrices with entries from F, with the group operation that of matrix multiplication. ... Cycle diagram of Q. Each color specifies a series of powers of any element connected to the identity element (1). ... In mathematics, the elements of any group may be partitioned into conjugacy classes; members of the same conjugacy class share many properties, and study of conjugacy classes reveals many important features of a groups structure. ... In mathematics, a finite group is a group which has finitely many elements. ... In mathematics, given a prime number p, a p-group is a group in which each element has a power of p as its order. ...

See also


  Results from FactBites:
 
Group Theory (487 words)
Group Theory is one of the most powerful mathematical tools used in Quantum Chemistry and Spectroscopy.
The key to applying Group Theory is to be able to identify the "Point Group" of the molecule i.e.
Therefore the first step in applying Group Theory to molecular properties is to identify the complete set of Symmetry Elements possessed by the molecule.
MSN Encarta - Romania (1012 words)
  More results at FactBites »


 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments
Please enter the 5-letter protection code

Want to know more?
Search encyclopedia, statistics and forums:

 


Lesson Plans | Student Area | Student FAQ | Reviews | Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms.