General Linear Group not Abelian

In summary, to show that the general linear group GL(3,R) with matrix multiplication is not an abelian group, we need to find two matrices that do not commute. By trying out a few examples, we can see that the matrices A and B given by A=[0 -1 0; 1 0 0; 0 0 1] and B=[1 0 0; 0 0 -1; 0 1 0] do not commute, thus proving that GL(3,R) is not an abelian group.
  • #1
mikael27
59
0

Homework Statement



Show that the general linear group GL(3,R) with matrix multiplication is not an abelian
group.


Homework Equations





The Attempt at a Solution



A group to be abelian we have to show that it satisfies the Commutativity.

a*b=b*a

How are we going to show that the general linear group GL(3,R) does not satisfies the Commutativity?
 
Physics news on Phys.org
  • #2
mikael27 said:

Homework Statement



Show that the general linear group GL(3,R) with matrix multiplication is not an abelian
group.


Homework Equations





The Attempt at a Solution



A group to be abelian we have to show that it satisfies the Commutativity.

a*b=b*a

How are we going to show that the general linear group GL(3,R) does not satisfies the Commutativity?

Find two matrices that don't commute. Just try a few. Just don't make them both diagonal.
 
  • #3
Take

A= 0 -1 0
1 0 0
0 0 1

B= 1 0 0
0 0 -1
0 1 0

A*B= 0 0 1
1 0 0
0 1 0

B*A= 0 -1 0
0 0 -1
1 0 0

So the two matrices do not commute as A*B=B*A and hence it is not abelian
 
  • #4
Take

A=
0 -1 0
1 0 0
0 0 1

B=
1 0 0
0 0 -1
0 1 0

A*B=
0 0 1
1 0 0
0 1 0

B*A=
0 -1 0
0 0 -1
1 0 0

So the two matrices do not commute as A*B=B*A and hence it is not abelian
 
  • #5
mikael27 said:
Take

A=
0 -1 0
1 0 0
0 0 1

B=
1 0 0
0 0 -1
0 1 0

A*B=
0 0 1
1 0 0
0 1 0

B*A=
0 -1 0
0 0 -1
1 0 0

So the two matrices do not commute as A*B=B*A and hence it is not abelian

That's just fine. Wasn't that easy?
 
  • #6
Yes easier than i expected...Thanks !
 

Related to General Linear Group not Abelian

1. What is the General Linear Group?

The General Linear Group is a mathematical concept that represents the set of all invertible matrices of a given order. In other words, it is the group of all possible transformations that can be applied to a vector space without changing its dimension.

2. What does it mean for a group to be Abelian?

A group is considered Abelian if its operation is commutative, meaning that the order in which the elements are multiplied does not affect the end result. In simpler terms, the group's operation is commutative if a*b = b*a for all elements a and b in the group.

3. Why is the General Linear Group not Abelian?

The General Linear Group is not Abelian because the operation of matrix multiplication is not commutative. This means that the order in which matrices are multiplied matters, and therefore the group cannot be considered Abelian.

4. What are some applications of the General Linear Group?

The General Linear Group has various applications in fields such as physics, engineering, and computer science. It is used to represent transformations in quantum mechanics, to solve systems of linear equations in engineering, and to perform operations on images and graphics in computer science.

5. Are there other types of groups that are not Abelian?

Yes, there are many other types of groups that are not Abelian. Some examples include the symmetric group, the dihedral group, and the quaternion group. In fact, most groups are not Abelian, making the Abelian property a special and unique characteristic of certain groups.

Similar threads

  • Calculus and Beyond Homework Help
2
Replies
38
Views
5K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
Replies
1
Views
374
  • Calculus and Beyond Homework Help
Replies
2
Views
2K
  • Calculus and Beyond Homework Help
Replies
2
Views
974
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
14
Views
1K
  • Calculus and Beyond Homework Help
Replies
10
Views
2K
  • Calculus and Beyond Homework Help
Replies
4
Views
1K
Back
Top