From the Ehrenfest theorem, we know that the equation below is correct for any state ## \psi ##.(adsbygoogle = window.adsbygoogle || []).push({});

##m\frac{d^2}{dt^2}\langle x \rangle_{\psi} =-\langle \frac{\partial V(x)}{\partial x} \rangle_{\psi} ##

But then one of the definitions of coherent states is states for which the expected value of position operator in that state, satisfies equation above. But by the Ehrenfest theorem, there should be no state that doesn't satisfy the equation above. So it seems I'm confused about one of the things above but I can't find which one it is! I'll appreciate any hint.

Thanks

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# Ehrenfest theorem and coherent states

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