Normal mode analysis within a mutilated relaxation time approximation
Abstract
In this paper, we present a detailed analysis of normal modes based on the Boltzmann equation within the mutilated relaxation time approximation (RTA). Using this linearized effective kinetic description, our analysis encompasses a complete order calculation in wavenumber k, extending the conventional hydrodynamic mode analysis to intermediate and short-wavelength regions. Furthermore, our linear mode analysis can provide a natural classification of kinetic modes into collective modes and non-collective single-particle excitations. In the case of an energy-independent relaxation time, the behavior of hydrodynamic onset transitions is recovered (Romatschke in Eur Phys J C 76:352, 2016). However, for the case with an energy-dependent relaxation time, the distinct classification becomes less clear, as the location of hydrodynamic modes is not well separated from non-hydrodynamic modes.
Cite
@article{arxiv.2310.05606,
title = {Normal mode analysis within a mutilated relaxation time approximation},
author = {Jin Hu},
journal= {arXiv preprint arXiv:2310.05606},
year = {2025}
}
Comments
The version published in EPJC. 14 pages, 3 figures. Title changed. Any questions, comments, and criticism are welcome