Comment on "Long-lived spin plasmons in a spin-polarized two-dimensional electron gas"

Agarwal et al. [Phys. Rev. B 90, 155409 (2014)] predict a remarkably long--lived spin-plasmon for a two-dimensional electron liquid with imbalanced spin up and spin down population. We agree that the partially spin-polarized system offers interesting modes which deserve experimental verification, but disagree on the actual value of its dispersion relation.