# Anomalous behavior of dispersion curves in water-like systems and water

## TL;DR

This paper reveals that water-like systems exhibit an unusual decrease in excitation frequencies with rising temperature along isochores, indicating a new type of water anomaly related to dynamic properties.

## Contribution

It introduces the concept of anomalous temperature dependence of excitation frequencies as a new water anomaly based on dispersion curve analysis.

## Key findings

- Dispersion curves show decreasing frequencies with temperature in water-like systems.
- Both model systems exhibit this anomalous behavior, unlike normal liquids.
- This behavior suggests a new dynamic anomaly in water.

## Abstract

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.