Convergence of the hydrodynamic gradient expansion in relativistic kinetic theory

Autor:	Gavassino, Lorenzo
Rok vydání:	2024
Předmět:	Nuclear Theory Astrophysics - High Energy Astrophysical Phenomena High Energy Physics - Theory
Zdroj:	Phys. Rev. D 110, 094012 (2024)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevD.110.094012
Popis:	We rigorously prove that, in any relativistic kinetic theory whose non-hydrodynamic sector has a finite gap, the Taylor series of all hydrodynamic dispersion relations has a finite radius of convergence. Furthermore, we prove that, for shear waves, such radius of convergence cannot be smaller than $1/2$ times the gap size. Finally, we prove that the non-hydrodynamic sector is gapped whenever the total scattering cross-section (expressed as a function of the energy) is bounded below by a positive non-zero constant. These results, combined with well-established covariant stability criteria, allow us to derive a rigorous upper bound on the shear viscosity of relativistic dilute gases. Comment: 10 pages, No figures, Published on PRD, see https://journals.aps.org/prd/abstract/10.1103/PhysRevD.110.094012
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2408.14316 Zobrazit plný text záznamu View this record from Arxiv