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arXiv · 2307.08886

Universality of sound modes in kinetic theory

Xiaojian Du·Stephan Ochsenfeld·Sören Schlichting
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Abstract

We present a simple approach to extract hydrodynamic sound modes and non-hydrodynamic modes in kinetic theories from response functions of the energy-momentum tensor. By comparing the response functions in four types of kinetic theories, namely the Relaxation-Time Approximation, scalar $\phi^4$ theory, SU(3) Yang-Mills theory and QCD kinetic theory, we find a remarkable degree of universality for the sound mode, even beyond the hydrodynamic regime.

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Xiaojian Du, Stephan Ochsenfeld, Sören Schlichting. 2023-07-17. Universality of sound modes in kinetic theory. https://arxiv.org/abs/2307.08886

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