Find all possible Jordan forms

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In summary, the conversation discusses a problem involving a linear application and its Jordan forms and characteristic polynomial. It is explained that the Jordan form is a matrix with the real eigenvalues of the original matrix on its diagonal, possibly with "1" just above each diagonal. The possible Jordan forms of the linear application are then discussed, including the use of blocks to represent duplicate eigenvalues. It is also mentioned that the characteristic polynomial can be factored to help determine the Jordan form.
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darksidemath
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Hi guys i have this problem in my linear algebra curse . let $T:\mathbb{Q}^3→\mathbb{Q}^3$ a linear application s.t $(T^7+2I)(T^2+3T+2I)^2=0$
can you find all possible Jordan forms of T and related characteristic polynomial ? I am totally lost and that is the first time i see this type of problem
 
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First, do you understand what the "Jordan form" of a matrix is? It is another matrix having the real eigenvalues of the original matrix on its main diagonal possibly with "1" just above each diagonal. If all eigenvalues are distinct, the matrix is diagonalizable and its "Jordan form" IS that diagonal matrix. When there is a duplicate eigenvalue, there will be a block with that eigenvalue on the diagonal as many times as the multiplicity of the eigenvalue and "1" just above each eigenvalue.

Note that x^3+ 3x+ 2= (x+ 1)(x+ 2). So -1 and -2 are eigenvalues and the "Jordan form" will include the block \(\displaystyle \begin{bmatrix}-1 & 0 \\ 0 & -2\end{bmatrix}\).

The other factor, \(\displaystyle x^7+ 2\) has the single real zero, \(\displaystyle -\sqrt[7]{2}\) and 6 complex roots, three pairs of complex conjugates. The Jordan form matrix will have \(\displaystyle -\sqrt[7]{2}\) on the main diagonal. a pair of complex conjugates, say a+ bi and a- bi, will give a submatrix of the form \(\displaystyle \begin{bmatrix}a & b \\ -b & a \end{bmatrix}\)
 

1. What is a Jordan form?

A Jordan form is a type of matrix that represents a linear transformation on a vector space. It is diagonalizable and has a specific structure that makes it useful for solving systems of linear equations.

2. How do you find all possible Jordan forms?

To find all possible Jordan forms, you need to start by finding the eigenvalues of the matrix. Then, for each eigenvalue, you need to find the corresponding eigenvectors and determine their geometric multiplicity. Finally, you can use this information to construct the Jordan form for the matrix.

3. What is the significance of finding all possible Jordan forms?

Finding all possible Jordan forms allows us to fully understand the behavior of a linear transformation on a vector space. It also helps us to solve systems of linear equations and make predictions about the long-term behavior of a system.

4. Can a matrix have multiple Jordan forms?

Yes, a matrix can have multiple Jordan forms. This is because a matrix can have multiple eigenvalues with different geometric multiplicities, leading to different possible Jordan forms.

5. Are there any limitations to finding all possible Jordan forms?

There are some limitations to finding all possible Jordan forms, as it can be a time-consuming process for larger matrices. Additionally, not all matrices have a Jordan form, as they may not be diagonalizable or may have complex eigenvalues.

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