Formula_3485

\[f_{i_{1} \ldots i_{n}}\left(\varepsilon_{1}, \ldots, \varepsilon_{n} ; t\right)=\frac{\partial^{n}}{\partial \varepsilon_{1} \ldots \partial \varepsilon_{n}} \mathrm{E}\left[\xi_{i_{1}}\left(\varepsilon_{1}, t\right) \ldots \xi_{i_{n}}\left(\varepsilon_{n}, t\right)\right],\]