  Exceptional points show great prospects for applications such as imaging,
sensing and designing lasers. Recently, systems with amplifying active medium
exhibiting pump-induced exceptional points have attracted much attention due to
possibility of controlling strong coupling between light and matter with the
aid of pumping. In such structures, the interaction of active molecules with
external degrees of freedom, such as phonons or impurities, leads to the
destruction of the correlation between polarizations of different molecules. We
study the effect of the correlations decay on a system behavior near
pump-induced exceptional point. We show that strong coupling persists and
eigenvectors together with eigenfrequencies coalesce at a negative value of
population inversion, regardless of correlation decay magnitude. Thus, we show
that exceptional points are robust to correlation decay, which is crucial for
designing systems with exceptional points.
