“…However, we note that, for higher noise strength (η ≥ 0.6) and large density, there are deviations from this particular scaling. Nevertheless, the To obtain a broader picture concerning the particlenumber fluctuations in the systems of self-propelled particles, in this section we compare the particle-number fluctuations in the Vicsek model, its variant and a system of active Brownian particles [5], which, unlike the Vicsek-like models, does not have any alignment interactions and was previously studied using additivity prop-erty [15]. Indeed, in the disordered isotropic phase, one would expect that, on the coarse-grained level, the presence of an alignment interaction would possibly change only the relaxation time scale of the polarization density field.…”