Understanding Linear Maps and Exterior Algebras

In summary, the homework statement is asking for help understanding how to solve a linear map. They state that they do not understand the question and need help understanding it. The problem is not stated in clear terms so the student cannot help.
  • #1
Diffy
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0

Homework Statement


Please, I just am trying to understand the question. I wish to prove it on my own, but the way the question is phrased makes no sense.

So here it is:

Let us define the linear map
[tex]\phi : V^{*} \otimes \bigwedge^{i} V \rightarrow \bigwedge^{i-1} V[/tex]

by the formula

[tex]\ell \otimes v_1 \wedge ... \wedge v_i \mapsto \sum_{s=1}^{i} (-1)^{s-1} \ell (v_s) v_1 \wedge ... \wedge \hat{v_s} \wedge ... \wedge v_s [/tex]

Prove that the map [tex] \phi [/tex] is well defined and does not depend on the choice of basis.

Homework Equations


Well all the usual definition of exterior algebras, and tensor products are needed.

The Attempt at a Solution



As I stated, I haven't started solving yet, I am simply trying to understand the question. I don't see how it goes to wedge i-1. What exactly is v hat sub s? Does that make i wedges?
I don't think this formula is going to i-1 wedges. Please help me to understand what is going on here.

Homework Statement


Homework Equations


The Attempt at a Solution


Homework Statement


Homework Equations


The Attempt at a Solution

 
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  • #2
What they are trying to notate by v hat sub s, is that the vector v_s is NOT included in the wedge product. All the other v_i's are. That's why it's an i-1 form.
 
  • #3
Now it makes sense!

Now I just have to solve the problem. Any hints are appreciated.
 
  • #4
Well there are two main ways to prove something is invariant
1 show it does not change with form
ie
let x and x' be different forms of x
if
f(x)=f(x')
f is invariant

2 provide an invariant definition
ie
define
f(x)
so that the form of x is not a factor

Since you have been provided a noninvariant definition
let Av be a change of basis
you want to show
l(v1)^v2^...^vn=l(Av1)^Av2^...^Avn=det(a)*l(v1)^v2^...^vn
with det(A)=1
 

1. What is the wedge product?

The wedge product, also known as the exterior product, is a mathematical operation used in multilinear algebra to create a new vector or form from two existing vectors. It is denoted by the symbol ∧ (wedge).

2. How is the wedge product different from the dot product?

The dot product is a scalar operation that results in a single value, while the wedge product is a vector operation that produces a new vector or form. The dot product measures the similarity of two vectors, while the wedge product measures the area or volume spanned by two vectors.

3. What are some applications of the wedge product in science?

The wedge product has many applications in physics, engineering, and computer science. It is used in electromagnetism to calculate the magnetic flux and in mechanics to calculate the moment of inertia. It is also used in computer graphics for 3D rendering and in computer vision for image processing.

4. How is the wedge product calculated?

The wedge product of two vectors, A and B, is calculated by taking the cross product of the two vectors and then multiplying it by the sine of the angle between them. It can also be calculated using the determinant of a matrix formed by the components of the two vectors.

5. Can the wedge product be extended to more than two vectors?

Yes, the wedge product can be extended to any number of vectors. In fact, it is a fundamental operation in the field of differential forms, which extends the concept to an arbitrary number of dimensions. The resulting form is called the exterior product of the vectors.

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