Formula_17965

\[\begin{gathered}|\Psi(s)\rangle=\left[1-\frac{i T}{\hbar} \int_{0}^{s} \hat{H}(u) d u-\right. \\\left.-\frac{T^{2}}{\hbar^{2}} \int_{0}^{s} \int_{0}^{u} \hat{H}(u) H(v) d u d v+\ldots\right]|\Psi(0)\rangle .\end{gathered}\]