= Unnormalized bosonic coherent state
{title2=$|\psi\rangle=e^{\psi a^\dagger}|0\rangle$}
An <unnormalized bosonic coherent state> is $|\psi\rangle=e^{\psi a^\dagger}|0\rangle$ for a complex label $\psi$. The <canonical commutation relation> gives $a|\psi\rangle=\psi|\psi\rangle$ and overlap $\langle\psi|\psi'\rangle=e^{\bar\psi\psi'}$. Multiplication by $e^{-|\psi|^2/2}$ produces a normalized <coherent state>. The unnormalized form makes the <coherent-state resolution of identity> and thermal time slicing particularly simple.
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