We show that the presented in Phys.Rev.B, v.101, 214312 (2020) theoretical expressions for longitudinal current spectral function CL(k,ω) and dispersion of collective excitations are not correct. Indeed, they are not compatible with the continuum limit and CL(k,ω→0) contradicts the continuity equation.
@article{arxiv.2008.01549,
title = {Comment on "Collective modes and gapped momentum states in liquid Ga: Experiment, theory, and simulation"},
author = {T. Bryk and I. Mryglod and G. Ruocco},
journal= {arXiv preprint arXiv:2008.01549},
year = {2021}
}