Complex conjugation in inner product space?

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SUMMARY

The discussion centers on the complexities of complex conjugation in inner product spaces, particularly in relation to symmetric matrices and eigenvalues. The user, ATY, seeks clarification on why the difference vector δx(t) becomes complex conjugated in the derivation presented in the linked thesis, specifically after equation D.8. A respondent highlights the properties of the Hermitian product and the implications of eigenvectors associated with complex matrices, emphasizing that the notation with the bar is relevant only when the matrix has real entries.

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ATY
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I got the following derivation for some physical stuff (the derivation itself is just math)
http://thesis.library.caltech.edu/5215/12/12appendixD.pdf
I understand everything until D.8.

So in the equation ε is a symmetric matrix and δx(t) is just the difference between two points.

After D.7 they get the eigenvalue and eigenvectors from ε. The text says that my δx(t) gets aligned in the same direction as the the eigenvektor of the largest eigenvalue (this would be my explanation for the fact that there is no eigenvector in the scalar product, but this might be wrong, cause I do not know much about eigenvectors).
But what I don't get is why in D.8. my δx(t) is suddenly complex conjugated. I can not find the reason for this.
I would be really happy about any explanation.

have a nice day
ATY

PS: sorry for the weird titel. Had no clue how to describe my problem (mea culpa)
 
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Hi, I don't know if can help but ##\langle \overline{\delta(x)},\lambda \overline{\delta(x)} \rangle=\overline{\lambda} \langle \overline{\delta(x)}, \overline{\delta(x)} \rangle ## for the properties of the hermitian product and your eigenvector is the eigenvector of the conjugate ##\lambda##, so why the notation with the bar. But this is true only if the matrix has real entries so ##\overline{A}=A## ...
I think you must see how is defined the inner product on your manifold possible there are remarcable properties ...
 
Just a quick reminder: if you are considering complex inner products, you have \left\langle x, y \right\rangle = \overline{\left\langle y, x \right\rangle}.
 

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