Interpreting Complex Eigenvalues in Comsol Analysis

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Complex eigenvalues in Comsol analysis often arise from the nature of the polynomial equations being solved, particularly in eigenvalue problems like those involving stress tensors. These complex values can indicate instability or non-conservative systems. Interpreting complex eigenvalues typically involves understanding their real and imaginary components, where the real part relates to frequency and the imaginary part indicates damping. Taking the absolute value of complex eigenvalues is not standard practice, as it may not accurately represent the physical system's behavior. Proper interpretation requires careful consideration of the context and implications of these complex values in the analysis.
ra123
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Hey,
Im working with Comsol and doing some eigenvalue analysis.
Why is sometimes the eigenvalues are complex numbers and not real number frequencies?
How should I interpret these complex eigenvalues?
Thanks
 
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They are sometimes imaginary because, at the heart of eigenvalue solving (the ones that I know of anyways) is solving a polynomial for it's roots. For example, finding the principal stresses in a 3x3 stress tensor is an eigenvalue problem. In that you are solving for the roots of a third order polynomial.
 
okaay great, so can i just take the absolute value as the eigenfrequency to work with?
 

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