scholarly journals SHOCK WAVE COLLISIONS IN AdS5: APPROXIMATE NUMERICAL SOLUTIONS

2011 ◽  
Vol 22 (12) ◽  
pp. 1317-1342 ◽  
Author(s):  
BIN WU ◽  
PAUL ROMATSCHKE
Keyword(s):  
Shock Wave ◽  
Black Hole ◽  
Numerical Solutions ◽  
Initial Conditions ◽  
Early Time ◽  
Heavy Ion ◽  
Late Time ◽  
Time Behavior ◽  
Ion Collisions ◽  
Bulk System

We numerically study the evolution of a boost-invariant [Formula: see text] SYM medium using AdS/CFT . We consider a toy model for the collision of gravitational shock waves, finding that the energy density first increases, reaches a maximum and then starts to decrease, matching hydrodynamics for late times. For the initial conditions we consider, the hydrodynamic scale governing the late time behavior is to very good approximation determined by the area of the black hole horizon at initial times. Our results provide a toy model for the early time evolution of the bulk system in heavy-ion collisions at RHIC and the LHC.

scholarly journals Early- and Late-Time Behavior of Attractors in Heavy-Ion Collisions

2020 ◽  
Vol 124 (10) ◽  
Author(s):  
Aleksi Kurkela ◽  
Wilke van der Schee ◽  
Urs Achim Wiedemann ◽  
Bin Wu
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Late Time ◽  
Time Behavior ◽  
Ion Collisions

scholarly journals Early Time Modifications to the Buoyancy-Drag Model for Richtmyer–Meshkov Mixing

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
David L. Youngs ◽  
Ben Thornber
Keyword(s):  
Initial Conditions ◽  
Mean Field ◽  
Early Time ◽  
Growth Exponent ◽  
Late Time ◽  
Time Behavior ◽  
Mixing Zone ◽  
Drag Model ◽  
Model Based ◽  
Self Similar

Abstract The Buoyancy-Drag model is a simple model, based on ordinary differential equations, for estimating the growth in the width of a turbulent mixing zone at an interface between fluids of different densities due to Richtmyer–Meshkov and Rayleigh–Taylor instabilities. The model is calibrated to give the required self-similar behavior for mixing in simple situations. However, the early stages of the mixing process are very dependent on the initial conditions and modifications to the Buoyancy-Drag model are then needed to obtain correct results. In a recent paper, Thornber et al. (2017, “Late-Time Growth Rate, Mixing, and Anisotropy in the Multimode Narrowband Richtmyer–Meshkov Instability: The θ-Group Collaboration,” Phys. Fluids, 29, p. 105107), a range of three-dimensional simulation techniques was used to calculate the evolution of the mixing zone integral width due to single-shock Richtmyer–Meshkov mixing from narrowband initial random perturbations. Further analysis of the results of these simulations gives greater insight into the transition from the initial linear behavior to late-time self-similar mixing and provides a way of modifying the Buoyancy-Drag model to treat the initial conditions accurately. Higher-resolution simulations are used to calculate the early time behavior more accurately and compare with a multimode model based on the impulsive linear theory. The analysis of the iLES data also gives a new method for estimating the growth exponent, θ (mixing zone width ∼ tθ), which is suitable for simulations which do not fully reach the self-similar state. The estimates of θ are consistent with the theoretical model of Elbaz and Shvarts (2018, “Modal Model Mean Field Self-Similar Solutions to the Asymptotic Evolution of Rayleigh-Taylor and Richtmyer-Meshkov Instabilities and Its Dependence on the Initial Conditions,” Phys. Plasmas, 25, p. 062126).

scholarly journals Kinetic evolution of the glasma and thermalization in heavy-ion collisions

2014 ◽  
Vol 23 (03) ◽  
pp. 1430003 ◽  
Author(s):  
Xu-Guang Huang ◽  
Jinfeng Liao
Keyword(s):  
Heavy Ion Collisions ◽  
Initial Conditions ◽  
Early Time ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Relativistic Heavy Ion Collisions ◽  
Hydrodynamic Behavior ◽  
Ion Collisions ◽  
Weakly Coupled ◽  
Far From Equilibrium

In relativistic heavy-ion collisions, a highly occupied gluonic matter is created shortly after initial impact, which is in a nonthermal state and often referred to as the Glasma. Successful phenomenology suggests that the glasma evolves rather quickly toward the thermal quark–gluon plasma (QGP) and a hydrodynamic behavior emerges at a very early time ~ô(1) fm/c. Exactly how such "apparent thermalization" occurs and connects the initial conditions to the hydrodynamic onset, remains a significant challenge for theory as well as phenomenology. We briefly review various ideas and recent progress in understanding the approach of the glasma to the thermalized QGP, with an emphasis on the kinetic theory description for the evolution of such far-from-equilibrium and highly overpopulated, thus weakly-coupled yet strongly interacting glasma.

THE BLACK HOLE ENTROPY BOUND AND THE MAXIMUM TEMPERATURE FOR MESON FORMATION IN THE NUCLEAR FIREBALL

1991 ◽  
Vol 06 (33) ◽  
pp. 3039-3045 ◽  
Author(s):  
JISHNU DEY ◽  
MIRA DEY ◽  
MARCELO SCHIFFER ◽  
LAURO TOMIO
Keyword(s):  
Black Hole ◽  
Simple Model ◽  
Black Hole Entropy ◽  
Heavy Ion ◽  
Black Hole Thermodynamics ◽  
Maximum Temperature ◽  
Ion Collisions ◽  
Pion Interferometry ◽  
Entropy Bound ◽  
Confined System

The entropy bound from black hole thermodynamics can be invoked to set limits for temperatures at which hadrons can survive as a confined system. We find that this implies that the pion can be formed in heavy ion collisions, much later than heavier mesons, for example the ρ-meson, when the fireball is cooler. The temperature found in a simple model agree qualitatively with experiment. We also suggest that this may be the reason why in pion interferometry experiments the space-time volume of the pion source seems large.

Effects of geometric similarity ratio on the disturbance amplitude of shock-wave front in viscosity measurement

2021 ◽  
pp. 2150330
Author(s):  
Kai Yang ◽  
Quan-Yu Xu ◽  
Xiao Wu ◽  
Xiao-Juan Ma
Keyword(s):  
Shock Wave ◽  
Phase Shift ◽  
Wave Front ◽  
Shock Wave Front ◽  
Numerical Solutions ◽  
Initial Conditions ◽  
Viscosity Measurement ◽  
Geometric Similarity ◽  
Similarity Ratio ◽  
Simulation Results

Geometric similarity ratio is one of the important factors that affects the disturbance amplitude of shock-wave front in viscosity measurement. In this paper, the Euler difference scheme of two-dimensional (2D) equations of viscous fluid mechanics is used to simulate the disturbance amplitude damping curves under different geometric similarity ratios, and the corresponding numerical solutions are shown. The samples of aluminum shocked to 80 GPa are taken as an example. The simulation results show that the initial conditions, material viscosity, wavelength, and sample geometric similarity ratio affect the evolution of the shock front sine wave disturbance. For flyer-impact flow field, the phase shift increases from 0 to a certain value with the viscosity coefficient for sample with wavelength [Formula: see text] mm and geometric similarity ratio [Formula: see text], 0.1. So, the geometric similarity method can be used to measure the viscosity of material. But it is found that the phase shift is sensitive to the geometric similarity ratio, which should be considered in Zaidel’s equation. So, some flyer-impact experiments will be carried out to determine the simulation results, and find the quantity relation of phase shift and viscosity of material in the future investigation.

scholarly journals Reflected entropy for an evaporating black hole

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Tianyi Li ◽  
Jinwei Chu ◽  
Yang Zhou
Keyword(s):  
Black Hole ◽  
Cross Section ◽  
Early Time ◽  
Three Dimensions ◽  
Late Time ◽  
Mixed States ◽  
Correlation Measure ◽  
Extremal Surface ◽  
Brane Model ◽  
The Right

Abstract We study reflected entropy as a mixed state correlation measure in black hole evaporation. As a measure for bipartite mixed states, reflected entropy can be computed between black hole and radiation, radiation and radiation, and even black hole and black hole. We compute reflected entropy curves in three different models: 3-side wormhole model, End-of-the-World (EOW) brane model in three dimensions and two-dimensional eternal black hole plus CFT model. For 3-side wormhole model, we find that reflected entropy is dual to island cross section. The reflected entropy between radiation and black hole increases at early time and then decreases to zero, similar to Page curve, but with a later transition time. The reflected entropy between radiation and radiation first increases and then saturates. For the EOW brane model, similar behaviors of reflected entropy are found.We propose a quantum extremal surface for reflected entropy, which we call quantum extremal cross section. In the eternal black hole plus CFT model, we find a generalized formula for reflected entropy with island cross section as its area term by considering the right half as the canonical purification of the left. Interestingly, the reflected entropy curve between the left black hole and the left radiation is nothing but the Page curve. We also find that reflected entropy between the left black hole and the right black hole decreases and goes to zero at late time. The reflected entropy between radiation and radiation increases at early time and saturates at late time.

scholarly journals Aspects of Relativistic Heavy-Ion Collisions

Universe ◽  
2020 ◽  
Vol 6 (5) ◽  
pp. 61 ◽  
Author(s):  
Georg Wolschin
Keyword(s):  
Heavy Ion Collisions ◽  
Initial Conditions ◽  
Hadron Collider ◽  
Heavy Ion ◽  
Charged Hadron ◽  
Distribution Functions ◽  
Relativistic Heavy Ion Collisions ◽  
Short Time Scale ◽  
Relativistic Heavy Ion Collider ◽  
Ion Collisions

The rapid thermalization of quarks and gluons in the initial stages of relativistic heavy-ion collisions is treated using analytic solutions of a nonlinear diffusion equation with schematic initial conditions, and for gluons with boundary conditions at the singularity. On a similarly short time scale of t ≤ 1 fm/c, the stopping of baryons is accounted for through a QCD-inspired approach based on the parton distribution functions of valence quarks, and gluons. Charged-hadron production is considered phenomenologically using a linear relativistic diffusion model with two fragmentation sources, and a central gluonic source that rises with ln 3 ( s N N ) . The limiting-fragmentation conjecture that agrees with data at energies reached at the Relativistic Heavy-Ion Collider (RHIC) is found to be consistent with Large Hadron Collider (LHC) data for Pb-Pb at s N N = 2.76 and 5.02 TeV. Quarkonia are used as hard probes for the properties of the quark-gluon plasma (QGP) through a comparison of theoretical predictions with recent CMS, ALICE and LHCb data for Pb-Pb and p-Pb collisions.

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