How do I find the eigenvectors for matrices V & T with known eigenvalues?

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In summary, the conversation discusses finding eigenvectors for given matrices using the eigenvalues found through omega square. There is confusion about the methodology and the role of the T matrix. The concept of eigenvectors being determined up to a multiplicative constant is explained, and it is mentioned that they can be normalized. The conversation also touches on the idea of degenerate subspaces and the possibility of different eigenvectors spanning the same subspace. Finally, the question of normalizing eigenvectors is addressed.
  • #1
suckstobeyou
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Hi, I've got these two matrices (V & T) and omega square, which is what I have found to be the eigenvalues. Could anyone tell me if this is the way to find the eigenvectors for these matrices and if they are correct?
Thanks...
http://img305.imageshack.us/img305/6937/ok4zd.jpg
 
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  • #2
I'm a little confused with your methodology...I believe it's the T matrix that is throwing me off. Why is there an 'm' in the vector? Are you multiplying an identity matrix by 'm' just to get rid of the 1/m in the omega value?

If my understanding is correct it seems what you have done is fine except that I believe that your subtraction is backwards. I havn't done it myself to see if it makes a differce. But when finding eigenvectors I believe that you must have Vij - (wn)^2*Tij. Like I said, I havn't run through this on pencil and paper so I don't know how much of an effect this will make.

Otherwise, if what I think you are doing is correct, everything looks right to me.
 
  • #3
yes I think that's why I multiplied m. One other question is x2

[1 ]
[-1]

or

[-1]
[1 ]

how can you know which one it should be? or maybe those two are the same?

thanks again...
 
  • #4
Eigenvectors are determined up to a multiplicative constant, so [1 -1] is the same eigenvector as [-1 1] as far as the eigenvalue goes. Now, if they form a degenerate subspace (i.e. they both have eigenvalue 2) things get slightly more interesting, but not really.
 
  • #5
abszero said:
Eigenvectors are determined up to a multiplicative constant, so [1 -1] is the same eigenvector as [-1 1] as far as the eigenvalue goes. Now, if they form a degenerate subspace (i.e. they both have eigenvalue 2) things get slightly more interesting, but not really.

exactly. Even more cool is the fact that they don't even have to be [-1,1]/[1,-1]! They could be anything you want as long as a1=-a2 or -a1=a2! It could be [4,523,231,-4,523,231] or [-87,87], the possibilities are endless! Math is cool!
 
  • #6
Eigenvectors are determined up to a multiplicative constant, so [1 -1] is the same eigenvector as [-1 1] as far as the eigenvalue goes. Now, if they form a degenerate subspace (i.e. they both have eigenvalue 2) things get slightly more interesting, but not really.
We can say this more precisely: either of these eigenvectors constitute a basis for the eigenspace associated with this eigenvalue.

Or, if you prefer, [1 -1] and [-1 1] both span the same subspace.
 
  • #7
I see, so how do you normalize these eigenvectors?
 
  • #8
Is this near close to the normalized form?
http://img124.imageshack.us/img124/4827/scan39nn.jpg

Should I multiply the scalars into the vectors or leave them as is?

Thanks again...
 
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  • #9
Your normalized vectors look good to me. I'd multiply the scalars into the vectors (though it doesn't really matter).
 

1. What is an eigenvector solution problem?

An eigenvector solution problem is a mathematical problem that involves finding a special set of vectors, called eigenvectors, that satisfy a specific equation involving a given matrix. These eigenvectors are important because they represent the directions along which a linear transformation has the simplest effect.

2. How are eigenvectors and eigenvalues related in an eigenvector solution problem?

Eigenvectors and eigenvalues are intimately related in an eigenvector solution problem. Eigenvectors are the vectors that, when multiplied by a given matrix, result in a scaled version of the original vector. These scaling factors are the eigenvalues.

3. Why are eigenvectors and eigenvalues important in real-world applications?

Eigenvectors and eigenvalues have a wide range of applications in various fields, including physics, engineering, and data analysis. For example, in physics, eigenvectors are used to describe the direction and magnitude of the spin of a particle, while eigenvalues are used to determine the energy levels of a quantum system. In engineering, eigenvectors and eigenvalues are used to analyze the stability and natural frequencies of structures. In data analysis, eigenvectors and eigenvalues are used in techniques like principal component analysis to reduce the dimensionality of a dataset.

4. What methods are used to solve an eigenvector solution problem?

There are several methods for solving an eigenvector solution problem, including the power method, the QR algorithm, and the Jacobi method. These methods vary in their computational complexity and accuracy, but they all aim to find the eigenvalues and corresponding eigenvectors of a given matrix.

5. Are there any real-life examples of eigenvector solution problems?

Yes, there are many real-life examples of eigenvector solution problems. One common example is in image processing, where eigenvectors and eigenvalues are used to perform image compression and feature extraction. In finance, eigenvectors and eigenvalues are used to analyze stock market data and create investment portfolios. Additionally, in chemistry, eigenvectors and eigenvalues are used to describe molecular vibrations and electronic states.

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