Exploring the Equivalence of FG-Modules and Group Representations

In summary, Theorem (1) states that FG-Modules can be defined as a multiplication of a representation of G over F by a basis of V. Meanwhile, Theorem (2) shows that the use of FG-Modules allows for the application of ring theory in addition to Maschke's Theorem. Overall, the use of FG-Modules provides an alternative language for discussing group representations and allows for the use of additional theorems from ring theory.
  • #1
OMM!
15
0
There is a Theorem that says FG-Modules are equivalent to group representations:


"(1) If [itex]\rho[/itex] is a representation of G over F and V = [itex]F^{n}[/itex], then V becomes an FG-Module if we define multiplication vg by: vg = v(g[itex]\rho[/itex]), for all v in V, g in G.

(2) If V is an FG-Module and B a basis of V, then [itex]\rho[/itex]: g [itex]\mapsto[/itex] [itex][g]_{B}[/itex] is a representation of G over F, for all g in G"


I've been told and I have read that using FG-Modules is advantageous to using group representations, but what exactly is the advantage of this, other than getting results like Maschke's Theorem?!

Thanks for any help!
 
Physics news on Phys.org
  • #2
I don't see an advantage. It is simply another language, nothing else. And it is restricted to linear representations. We can use the language and theorems of ring theory, not only Maschke, which might be an advantage.
 

1. What are modules and representations?

Modules and representations are mathematical concepts used in the study of groups and algebras. A module is a vector space over a ring, whereas a representation is a way of associating a group with a module. Essentially, they are both ways of understanding the structure and behavior of algebraic objects.

2. How are modules and representations related?

Modules and representations are closely related in that a representation can be thought of as a special type of module. In a representation, the group elements act as linear transformations on the associated module. This allows us to study the properties of a group through its actions on a module.

3. What are the applications of modules and representations?

Modules and representations have many applications in various areas of mathematics, including algebraic geometry, number theory, and representation theory. They are also used in physics and chemistry, particularly in the study of symmetry and group theory.

4. What is the difference between a module and a representation?

The main difference between a module and a representation is that a module is a vector space over a ring, while a representation is a module that has an associated group acting on it. In other words, a representation is a module with some additional structure that allows us to study the group through its actions.

5. How are modules and representations used in representation theory?

Modules and representations are central to representation theory, which is the study of group actions on vector spaces. In representation theory, we use modules and representations to understand the structure and behavior of groups, and to classify and study the different types of representations that a group can have.

Similar threads

  • Linear and Abstract Algebra
Replies
3
Views
2K
  • Linear and Abstract Algebra
Replies
4
Views
1K
  • Linear and Abstract Algebra
Replies
18
Views
1K
  • Linear and Abstract Algebra
Replies
1
Views
1K
  • Linear and Abstract Algebra
Replies
4
Views
2K
Replies
2
Views
976
  • Linear and Abstract Algebra
Replies
1
Views
1K
  • Linear and Abstract Algebra
Replies
6
Views
3K
  • Linear and Abstract Algebra
Replies
1
Views
1K
Replies
5
Views
1K
Back
Top