Formula_2663

\[\lim _{\left|\boldsymbol{r}_{1}-\boldsymbol{r}_{2}\right| \rightarrow \infty}\left\langle\left[\hat{\varphi}\left(t_{1}, \boldsymbol{r}_{1} ; \sigma_{1}\right), \hat{\varphi}\left(t_{2}, \boldsymbol{r}_{2} ; \sigma_{2}\right)\right]\right\rangle=0,\]