(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

why is the spectrum of the unitary operator the unit circle?

2. Relevant equations

i know that U^(-1)=U* and i know this makes U normal

i also know that normal means UU*=U*U

3. The attempt at a solution

i know that from spectral theory there is some lambda in the spectrum

such that abs(lambda)=1, but i dont understand why ALL of them are on

the unit circle. (i understand the operator, but spectrums are confusing to me.

thanks

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# Homework Help: Unitary operators

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