Characteristic polynomial splits into linear factors

In summary, a characteristic polynomial is a polynomial equation used to find the eigenvalues of a matrix. It is formed by taking the determinant of the matrix and subtracting the identity matrix multiplied by a variable. Linear factors are polynomial expressions of degree one that can be used to split a polynomial into a product. A characteristic polynomial splits into linear factors when it has distinct eigenvalues, allowing for easier computation and diagonalization of a matrix. However, there are cases where a characteristic polynomial may not split into linear factors, such as when the matrix has repeated or complex eigenvalues, in which case it may still be factored into irreducible terms.
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Is it true that the characteristic polynomial of an n by n matrix over GF(q) splits into linear factors over GF(q^n)?

I see that it must do if the polynomial is irreducible but what if it isn't?
 
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  • #2
Let p be an irreducible polynomial of degree k over GF(q). What does the splitting field of p (over GF(q)) look like?
 

FAQ: Characteristic polynomial splits into linear factors

What is a characteristic polynomial?

A characteristic polynomial is a polynomial equation that is used to find the eigenvalues of a matrix. It is formed by taking the determinant of the matrix and subtracting the identity matrix multiplied by a variable, usually denoted as lambda.

What are linear factors?

Linear factors are polynomial expressions of degree one, such as (x+2) or (3x-5). When a polynomial splits into linear factors, it means that the polynomial can be written as a product of these linear factors.

How does a characteristic polynomial split into linear factors?

A characteristic polynomial splits into linear factors when it has distinct eigenvalues. This means that each eigenvalue has a corresponding eigenvector, and the polynomial can be written as a product of (lambda - eigenvalue) terms.

Why is it important for a characteristic polynomial to split into linear factors?

When a characteristic polynomial splits into linear factors, it allows for easier computation of the eigenvalues of a matrix. It also allows for the diagonalization of a matrix, which is useful in solving systems of linear equations and other applications in mathematics and science.

Are there any cases where a characteristic polynomial does not split into linear factors?

Yes, there are cases where a characteristic polynomial may not split into linear factors. This can happen when the matrix has repeated eigenvalues or when the eigenvalues are complex numbers. In these cases, the polynomial may still be factored but into irreducible quadratic or higher degree terms.

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