Assume [tex] A [/tex] is a complex [tex] N \times N [/tex] matrix. It is well known that [tex] \max_{V \in U(N)} |Tr(AV)| = Tr(\sqrt{AA^{\dagger}})[/tex]. But what is(adsbygoogle = window.adsbygoogle || []).push({});

[tex] \max_{V \in U(N)} Re(Tr(AV)) [/tex]?

[tex] U(N) [/tex] is the group of unitary [tex] N \times N [/tex] matrices.

(I could not preview my post properly, so I apologize for any latex-misstakes )

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# Maximum of trace

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