English

Hydrodynamics as sound-speed approaches light-speed

High Energy Physics - Phenomenology 2024-04-04 v2

Abstract

I present the simplest 3+1 dimensional quantum field theory for which the speed of sound can be arbitrarily close to the speed of light. Examining the hydrodynamics, I find cases where the shear viscosity is finite, but the "shear relaxation coefficient" appears always to be divergently large.

Keywords

Cite

@article{arxiv.2404.01968,
  title  = {Hydrodynamics as sound-speed approaches light-speed},
  author = {Guy D. Moore},
  journal= {arXiv preprint arXiv:2404.01968},
  year   = {2024}
}

Comments

10 pages including figures. Added acknowledgments, corrected minor typos

R2 v1 2026-06-28T15:41:43.809Z