Fully Dynamical Simulation of Central Nuclear Collisions

144

Using holography, we study the evolution of a spatially homogeneous, far from equilibrium, strongly coupled N = 4 supersymmetric Yang-Mills plasma with a non-zero charge density or a background magnetic field. This gauge theory problem corresponds, in the dual gravity description, to an initial value problem in Einstein-Maxwell theory with homogeneous but anisotropic initial conditions. We explore the dependence of the equilibration process on different aspects of the initial departure from equilibrium and, while controlling for these dependencies, examine how the equilibration dynamics are affected by the presence of a non-vanishing charge density or an external magnetic field. The equilibration dynamics are remarkably insensitive to the addition of even large chemical potentials or magnetic fields; the equilibration time is set primarily by the form of the initial departure from equilibrium. For initial deviations from equilibrium which are well localized in scale, we formulate a simple model for equilibration times which agrees quite well with our results.

Section: Jhep07(2015)116mentioning

confidence: 99%

Far-from-equilibrium dynamics of a strongly coupled non-Abelian plasma with non-zero charge density or external magnetic field

Fuini

Yaffe

2015

144

“…By contrast, full non-linear simulations of collisions in AdS spacetime are in their infancy [3][4][5][6]. Validation of any such simulations requires benchmarking with perturbative results, either for the final ringdown stage or for intermediate stages of the process.…”

Section: Discussionmentioning

confidence: 99%

“…90) 6 Here, ρ = x 2 2 + x 2 3 should not be confused with the dimensionless holographic coordinate r/r0 used in section 3.1.…”

Section: Jhep01(2014)138mentioning

confidence: 99%

“…Using a new variable ρ = r/r 0 the above can be written in manifestly dimensionless format, 6) or equivalently…”

Section: Stability and Normal Modesmentioning

confidence: 99%

“…1 The study of these collision processes is challenging because one must solve Einstein's equations in a dynamical setting, which generically must be done numerically. Several such studies have now been performed in cases in which the gauge theory is a Conformal Field Theory (CFT) [3][4][5][6]. 2 The goal of this paper is to give a first step towards extending this program to gravitational duals of confining gauge theories.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Holographic collisions in confining theories

Cardoso

Matéos

Pani

et al. 2014

Abstract:We study the gravitational dual of a high-energy collision in a confining gauge theory. We consider a linearized approach in which two point particles traveling in an AdSsoliton background suddenly collide to form an object at rest (presumably a black hole for large enough center-of-mass energies). The resulting radiation exhibits the features expected in a theory with a mass gap: late-time power law tails of the form t −3/2 , the failure of Huygens' principle and distortion of the wave pattern as it propagates. The energy spectrum is exponentially suppressed for frequencies smaller than the gauge theory mass gap. Consequently, we observe no memory effect in the gravitational waveforms. At larger frequencies the spectrum has an upward-stairway structure, which corresponds to the excitation of the tower of massive states in the confining gauge theory. We discuss the importance of phenomenological cutoffs to regularize the divergent spectrum, and the aspects of the full non-linear collision that are expected to be captured by our approach.

Entropy production far from equilibrium in a chiral charged plasma in the presence of external electromagnetic fields

Cartwright

2021

We report on the time evolution of a charged strongly coupled N = 4 SYM plasma with an axial anomaly subjected to strong electromagnetic fields. The evolution of this plasma corresponds to a fully backreacted asymptotically AdS5 solution to the Einstein-Maxwell-Chern-Simons theory. We explore the evolution of the axial current and production of axial charges. As an application we show that after a sufficiently long time both the entropy and the holographic entanglement entropy of a strip-like topology (both parallel to and transverse to the flow of axial current) grow linearly in time.