In the present paper we consider dispersion curves of longitudinal excitations of a model core-softened liquid and SPC/E model of water. We show that both systems demonstrate anomalous behavior of the excitation frequencies: the frequencies of the excitations can decrease with temperature along isochors, while in normal liquids they should increase. This observation allows to introduce one more water anomaly - anomalous dependence of excitation frequencies on temperature.
@article{arxiv.1812.09695,
title = {Anomalous behavior of dispersion curves in water-like systems and water},
author = {Yu. D. Fomin and E. N. Tsiok and V. N. Ryzhov and V. V. Brazhkin},
journal= {arXiv preprint arXiv:1812.09695},
year = {2018}
}