Michal P. Heller

Characteristics of thermalization of boost-invariant plasma from holography

We report on the approach toward the hydrodynamic regime of boost-invariant N=4 super Yang-Mills plasma at strong coupling starting from various far-from-equilibrium states at τ=0. The results are obtained through a numerical solution of Einsteins equations for the dual geometries, as described in detail in the companion article [M. P. Heller, R. A. Janik, and P. Witaszczyk, arXiv:1203.0755]. Despite the very rich far-from-equilibrium evolution, we find surprising regularities in the form of clear correlations between initial entropy and total produced entropy, as well as between initial entropy and the temperature at thermalization, understood as the transition to a hydrodynamic description. For 29 different initial conditions that we consider, hydrodynamics turns out to be definitely applicable for proper times larger than 0.7 in units of inverse temperature at thermalization. We observe a sizable anisotropy in the energy-momentum tensor at thermalization, which is nevertheless entirely due to hydrodynamic effects. This suggests that effective thermalization in heavy-ion collisions may occur significantly earlier than true thermalization.

Viscous hydrodynamics relaxation time from AdS/CFT correspondence

We consider an expanding boost-invariant plasma at strong coupling using the AdS/CFT correspondence for

Bulk curves from boundary data in holography

\mathcal{N}=4

A numerical relativity approach to the initial value problem in asymptotically Anti-de Sitter spacetime for plasma thermalization - an ADM formulation

super Yang-Mills theory. We determine the relaxation time in second order viscous hydrodynamics and find that it is around 30 times shorter than weak coupling expectations. We find that the nonsingularity of the dual geometry in the string frame necessitates turning on the dilaton which leads to a nonvanishing expectation value for

Strong Coupling Isotropization of Non-Abelian Plasmas Simplified

\mathrm{tr}{F}^{2}

Boost-invariant early time dynamics from AdS/CFT

behaving like

Hydrodynamics Beyond the Gradient Expansion: Resurgence and Resummation

{\ensuremath{\tau}}^{\ensuremath{-}10/3}

Entanglement, holography and causal diamonds

.

Equilibration Rates in a Strongly Coupled Nonconformal Quark-Gluon Plasma.

We embed spherical Rindler space – a geometry with a spherical hole in its center – in asymptotically AdS spacetime and show that it carries a gravitational entropy proportional to the area of the hole. Spherical AdS-Rindler space is holographically dual to an ultraviolet sector of the boundary field theory given by restriction to a strip of finite duration in time. Because measurements have finite durations, local observers in the field theory can only access information about bounded spatial regions. We propose a notion of differential entropy that captures uncertainty about the state of a system left by the collection of local, finite-time observables. For two-dimensional conformal field theories we use holography and the strong subadditivity of entanglement to propose a formula for differential entropy and show that it precisely reproduces the areas of circular holes in AdS3. Extending the notion to field theories on strips with variable durations in time, we show more generally that differential entropy computes the areas of all closed, inhomogenous curves on a spatial slice of AdS3. We discuss the extension to higher dimensional field theories, the relation of differential entropy to entanglement between scales, and some implications for the emergence of space from the RG flow of entangled field theories. vijay@physics.upenn.edu,czech@stanford.edu,bdchowdh@asu.edu,m.p.heller,J.deBoer@uva.nl ar X iv :1 31 0. 42 04 v3 [ he pth ] 1 1 Ju n 20 14

Coupling hydrodynamics to nonequilibrium degrees of freedom in strongly interacting quark-gluon plasma.

This article studies a numerical relativity approach to the initial value problem in Anti-de Sitter spacetime relevant for dual non-equilibrium evolution of strongly coupled non-Abelian plasma undergoing Bjorken expansion. In order to use initial conditions for the metric obtained in arXiv:0906.4423 we introduce new, ADM formalism-based scheme for numerical integration of Einsteins equations with negative cosmological constant. The key novel element of this approach is the choice of lapse function vanishing at fixed radial position, enabling, if needed, efficient horizon excision. Various physical aspects of the gauge theory thermalization process in this setup have been outlined in our companion article arXiv:1103.3452. In this work we focus on the gravitational side of the problem and present full technical details of our setup. We discuss in particular the ADM formalism, the explicit form of initial states, the boundary conditions for the metric on the inner and outer edges of the simulation domain, the relation between boundary and bulk notions of time, the procedure to extract the gauge theory energy-momentum tensor and non-equilibrium apparent horizon entropy, as well as the choice of point for freezing the lapse. Finally, we comment on various features of the initial profiles we consider.