Causality violations in realistic simulations of relativistic nuclear collisions

We show that relativistic causality is violated in the early stages of state-of-the-art heavy-ion hydrodynamic simulations of nuclear collisions. Up to 75% of the initial fluid cells violate nonlinear causality constraints, while superluminal propagation is observed by up to 15% the speed of light....

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Bibliographic Details
Main Authors: Plumberg Christopher, Almaalol Dekrayat, Dore Travis, Noronha Jorge, Noronha-Hostler Jacquelyn
Format: Article
Language:English
Published: EDP Sciences 2023-01-01
Series:EPJ Web of Conferences
Online Access:https://www.epj-conferences.org/articles/epjconf/pdf/2023/02/epjconf_sqm2022_06002.pdf
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Summary:We show that relativistic causality is violated in the early stages of state-of-the-art heavy-ion hydrodynamic simulations of nuclear collisions. Up to 75% of the initial fluid cells violate nonlinear causality constraints, while superluminal propagation is observed by up to 15% the speed of light. Only after 2-3 fm/c of evolution, do 50% of the fluid cells become definitely causal. Inclusion of pre-equilibrium evolution significantly reduces the number of acausal cells, but it does not eliminate them. Relativistic causality thus imposes constraints on the model parameter space of heavy-ion collision simulations.
ISSN:2100-014X