Calculating fluctuations and self-correlations numerically for causal charge diffusion in relativistic heavy-ion collisions

Stochastic hydrodynamics meets hydro-kinetics

“…Direct numerical simulations in Ref. [26] showed how the selfcorrelation looks for various values of τ Q , as depicted in the Fig. 6.…”

“…Noise generated at the same rapidity but at different times is correlated. Figure 2 illustrates what fluctuation propagation looks like in the presence of the Catteneo noise [26]. Figure 2 also illustrates the correlation introduced in the system due to colored noise.…”

“…10 of Ref. [26], specifically, the Dirac δ-function minus a Gaussian. Here, the noise fluctuations pumped in by white noise is effectively dispersed away with infinite signal propagation speed by the usual diffusion process.…”

“…Specifically, fluctuations are known to become important near critical points [19][20][21][22]. This has led to studies that investigate fluctuations in conserved quantities, such as electric charge, baryon number, and strangeness on an event-by-event basis [23][24][25][26]. Recently, there have also been studies of dynamic critical phenomena near a QCD critical point [22,[27][28][29][30].…”

Non-equilibrium cumulants within model A near the QCD critical point

“…Indeed, the off-equilibrium process plays an essential role in the dynamical evolution with phase transition to address the critical slowing down near a CP [29], and to reveal the domain formation at the first-order phase transition [30]. According to the classification scheme, the dynamic universality class of the QCD phase transition in heavy ion collisions is that of Model H, since it is governed by five conserved hydrodynamic modes [31][32][33][34][35][36][37]. Complete dynamical models such as chiral hydrodynamics [38][39][40][41] and Hydro+ [42][43][44] have been developed to describe the bulk evolution of the critical fluctuations of QCD matter in heavy ion collisions.…”