What happens in hydrodynamic simulations of heavy-ion collisions when causality is violated?

EPJ Web of Conferences 2026 Open access

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Authors: Lorenzo Gavassino, Henry Hirvonen, Jean-François Paquet, Mayank Singh, Gabriel S. Rocha
DOI: 10.1051/epjconf/202636404003
Cited by: 0
References: 10

Abstract

We summarize our recent investigations on how causality violations in Israel-Stewart-type relativistic viscous hydrodynamic simulations can give rise to both analytical and numerical instabilities. The classification of space-time regions into causal and stable ("good"), acausal but stable ("bad"), and acausal and unstable ("ugly") is reviewed. We compare the predictions of the MUSIC hydrodynamic solver with an analytical solution, and demonstrate how the acausality-driven instabilities develop in a simple one-dimensional scenario.

Fields of Study & Subjects

High-Energy Particle Collisions Research Dust and Plasma Wave Phenomena Pulsars and Gravitational Waves Research

Publication details

Journal / source
EPJ Web of Conferences
Publisher
EDP Sciences
Volume
364
Pages
04003–04003
Publication date
1 January 2026
Language
EN