Finite coupling corrections to holographic predictions for hot QCD

103

Pole-skipping is a recently discovered signature of many-body quantum chaos in collective energy dynamics. It establishes a precise connection between resummed, allorder hydrodynamics and the underlying microscopic chaos. In this paper, we demonstrate the existence of pole-skipping in holographic conformal field theories with higherderivative gravity duals. In particular, we first consider Einstein-Hilbert gravity deformed by curvature-squared (R 2 ) corrections and then type IIB supergravity theory with the α 3 R 4 term, where α is set by the length of the fundamental string. The former case allows us to discuss the effects of leading-order 1/N c corrections (with N c being the number of colours of the dual gauge group) and phenomenological coupling constant dependence. In Einstein-Gauss-Bonnet theory, pole-skipping turns out to be valid non-perturbatively in the Gauss-Bonnet coupling. The α 3 R 4 deformation enables us to study perturbative inverse 't Hooft coupling corrections (α 3 ∼ 1/λ 3/2 ) in SU (N c ), N = 4 supersymmetric Yang-Mills theory with infinite N c . While the maximal Lyapunov exponent characterising quantum chaos remains uncorrected, the butterfly velocity is shown to depend both on N c and the coupling. Several implications of the relation between hydrodynamics and chaos are discussed, including an intriguing similarity between the dependence of the butterfly velocity and the ratio of shear viscosity to entropy density on stringy corrections.

Section: Discussionmentioning

confidence: 76%

On the connection between hydrodynamics and quantum chaos in holographic theories with stringy corrections

Grozdanov

2019

103

“…This implies that those higher derivative terms can only be studied perturbatively, to avoid the emergence of instabilities, ghosts and other pathologies. Within this limit, these types of corrections have been vigorously studied in the past, exploring the correction of many different quantities (see [41] for a recent compilation of results). Recently, the relaxation of small stress tensor fluctuations in the thermal ensemble of N = 4 SYM has been studied in detail [42,43], (see also [44,45] for previous studies).…”

Section: Jhep04(2018)042mentioning

confidence: 99%

Resurgence and hydrodynamic attractors in Gauss-Bonnet holography

Casalderrey-Solana

Gushterov

Meiring

2018

Abstract:We study the convergence of the hydrodynamic series in the gravity dual of Gauss-Bonnet gravity in five dimensions with negative cosmological constant via holography. By imposing boost invariance symmetry, we find a solution to the Gauss-Bonnet equation of motion in inverse powers of the proper time, from which we can extract high order corrections to Bjorken flow for different values of the Gauss-Bonnet parameter λ GB . As in all other known examples the gradient expansion is, at most, an asymptotic series which can be understood through applying the techniques of Borel-Padé summation. As expected from the behaviour of the quasi-normal modes in the theory, we observe that the singularities in the Borel plane of this series show qualitative features that interpolate between the infinitely strong coupling limit of N = 4 Super Yang Mills theory and the expectation from kinetic theory. We further perform the Borel resummation to constrain the behaviour of hydrodynamic attractors beyond leading order in the hydrodynamic expansion. We find that for all values of λ GB considered, the convergence of different initial conditions to the resummation and its hydrodynamization occur at large and comparable values of the pressure anisotropy.

“…The regime of weak coupling can be described by the kinetic theory, while the transition from weak to strong coupling, i. e., the regime of intermediate coupling is not yet understood. Recently, an approach allowing one to obtain corrections to the regime of infinite coupling has been suggested in [10][11][12][13]. There it is shown that higher curvature corrections to the gravitational action, such as the GaussBonnet, Lovelock, R 4 or other terms, may give us a hint on what happens in the regime of intermediate coupling.…”

Section: Jhep09(2017)139mentioning

confidence: 99%

Quasinormal modes of Gauss-Bonnet-AdS black holes: towards holographic description of finite coupling

Konoplya

Zhidenko

2017

Here we shall show that there is no other instability for the EinsteinGauss-Bonnet-anti-de Sitter (AdS) black holes, than the eikonal one and consider the features of the quasinormal spectrum in the stability sector in detail.The obtained quasinormal spectrum consists from the two essentially different types of modes: perturbative and non-perturbative in the Gauss-Bonnet coupling α. The sound and hydrodynamic modes of the perturbative branch can be expressed through their Schwazrschild-AdS limits by adding a linear in α correction to the damping rates:2 ))i, where R is the AdS radius. The non-perturbative branch of modes consists of purely imaginary modes, whose damping rates unboundedly increase when α goes to zero. When the black hole radius is much larger than the anti-de Sitter radius R, the regime of the black hole with planar horizon (black brane) is reproduced. If the Gauss-Bonnet coupling α (or used in holography λ GB ) is not small enough, then the black holes and branes suffer from the instability, so that the holographic interpretation of perturbation of such black holes becomes questionable, as, for example, the claimed viscosity bound violation in the higher derivative gravity. For example, D = 5 black brane is unstable at |λ GB | > 1/8 and has anomalously large relaxation time when approaching the threshold of instability.