Causality violations in realistic simulations of heavy-ion collisions

Abstract

Causality is violated in the early stages of state-of-the-art heavy-ion hydrodynamic simulations. Such violations are present in up to 75% of the fluid cells in the initial time and only after 2-3 fm/$c$ of evolution do we find that 50% of the fluid cells are definitely causal. Superluminal propagation reaches up to 15% the speed of light in some of the fluid cells. The inclusion of pre-equilibrium evolution significantly reduces the number of acausal cells. Our findings suggests that relativistic causality may place constraints on the available parameter space of heavy-ion collision simulations when factored into more thorough statistical analyses.

v1 - 7 pages, 3 Figures, 1 Table, 102 References; v2 - 13 pages, 7 Figures, 1 Table, 108 References, 1 Appendix (as Supplemental Material); version published in Phys. Rev. C

References in corpus (18)

• The equation of state in (2+1)-flavor QCD
• Relativistic viscous hydrodynamics, conformal invariance, and holography
• 200 A GeV Au+Au collisions serve a nearly perfect quark-gluon liquid
• Alternative ansatz to wounded nucleon and binary collision scaling in high-energy nuclear collisions
• Triangularity and Dipole Asymmetry in Heavy Ion Collisions
• Event-by-event gluon multiplicity, energy density and eccentricities at RHIC and LHC
• Particle spectra in Pb-Pb collisions at 2.76 TeV
• Stable and causal relativistic Navier-Stokes equations
• Viscous Effects on the Mapping of the Initial to Final State in Heavy Ion Collisions
• Free-streaming approximation in early dynamics of relativistic heavy-ion collisions
• Multi-particle and charge-dependent azimuthal correlations in heavy-ion collisions at the Relativistic Heavy-Ion Collider
• Unified description of hadron yield ratios from dynamical core-corona initialization
• ${}^{16}{\mathrm{O}}^{16}\mathrm{O}$ at RHIC and the LHC comparing $\alpha$ clustering vs substructure
• Hydrodynamization and non-equilibrium Green's functions in kinetic theory
• Exploring theoretical uncertainties in the hydrodynamic description of relativistic heavy-ion collisions
• Hydrodynamic Predictions for Mixed Harmonic Correlations in 200 GeV Au+Au Collisions
• How large is the Knudsen number reached in fluid dynamical simulations of ultrarelativistic heavy ion collisions?
• Initial state fluctuations of QCD conserved charges in heavy-ion collisions

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