Analytic black branes in Lifshitz-like backgrounds and thermalization

Using black brane solutions in 5d Lifshitz-like backgrounds with arbitrary dynamical exponent $\nu$, we construct the Vaidya geometry, asymptoting to the Lifshitz-like spacetime, which represents a thin shell infalling at the speed of light. We apply the new Lifshitz-Vaidya background to study the thermalization process of the quark-gluon plasma via the thin shell approach previously successfully used in several backgrounds. We find that the thermalization depends on the chosen direction because of the spatial anisotropy. The plasma thermalizes thus faster in the transversal direction than in the longitudinal one. To probe the system described by the Lifshitz-like backgrounds, we also calculate the holographic entanglement entropy for the subsystems delineated along both transversal and longitudinal directions. We show that the entropy has some universality in the behavior for both subsystems. At the same time, we find that certain characteristics strongly depend on the critical exponent $\nu$.Comment: 39 pages, 23 figures; v3: typos corrected, references and clarifications added, version published in JHE

Probing the holographic model of N=4\mathcal{N} =4 SYM rotating quark-gluon plasma

We study Wilson loops in holographic duals of the $\mathcal{N}=4$ SYM quark-gluon plasma. For this we consider the Schwarzschild-$AdS_5$ and Kerr-$AdS_5$ black holes, which are dual to the non-rotating and rotating QGPs, correspondingly. From temporal Wilson loops we find the heavy quark potentials in both backgrounds. For the temperature above the critical temperature we observe the Coulomb-like behavior of the potentials. We find that increasing the rotation the interquark distance decreases, we also see that the increase of the temperature yields the similar behavior. Moreover, at high temperatures for certain values of parameters the potentials in Schwarzschild-$AdS_5$ and Kerr-$AdS_5$ are close to that one calculated in the AdS black brane with a planar horizon. We also explore holographic light-like Wilson-loops from which the jet-quenching parameters of a fast parton are extracted. We find that the rotation increases the value of the jet-quenching parameter. However, at high temperatures the jet-quenching parameters have a cubic dependence on the temperature as for the the AdS black brane.Comment: 32 pp, 11 fig

Stability analysis of holographic RG flows in 3d supergravity

We study holographic RG flows in a 3d supergravity model from the side of the dynamical system theory. The gravity equations of motion are reduced to an autonomous dynamical system. Then we find equilibrium points of the system and analyze them for stability. We also restore asymptotic solutions near the critical points. We find two types of solutions: with asymptotically AdS metrics and hyperscaling violating metrics. We write down possible RG flows between an unstable (saddle) UV fixed point and a stable (stable node) IR fixed point. We also analyze bifurcations in the model.Comment: 26 pp., 7 figure

Holographic Wilson Loops in the Confining Backgrounds at Zero Temperature

We study Wilson loops in the exact renormalization group ow at zero tempera- ture via the 5d holographic model that reproduces the behavior of the QCD running coupling. Calculating the time-like rectangular Wilson loop we show that the model includes a conning phase at T = 0 in the IR region

Thermalization of holographic Wilson loops in spacetimes with spatial anisotropy

In this paper, we study behaviour of Wilson loops in the boost-invariant nonequilibrium anisotropic quark-gluon plasma produced in heavy-ion collisions within the holographic approach. We describe the thermalization studying the evolution of the Vaidya metric in the boost-invariant and spatially anisotropic background. To probe the system during this process we calculate rectangular Wilson loops oriented in different spatial directions. We find that anisotropic effects are more visible for the Wilson loops lying in the transversal plane unlike the Wilson loops with partially longitudinal orientation. In particular, we observe that the Wilson loops can thermalizes first unlike to the order of the isotropic model. We see that Wilson loops on transversal contours have the shortest thermalization time. We also calculate the string tension and the pseudopotential at different temperatures for the static quark-gluon plasma. We show that the pseudopotential related to the configuration on the transversal plane has the screened Cornell form. We also show that the jet-quenching parameter related with the average of the light-like Wilson loop exhibits the dependence on orientations.Comment: 39 pages, 12 figures; v3: typos corrected, to appear in Nucl. Phys.

Heavy quarks in rotating plasma via holography

International audienceWe continue to explore the dynamics of a heavy quark in a strongly coupled rotating quark-gluon plasma within the holographic framework. We use the 5d Kerr-AdS black hole with two arbitrary rotating parameters to describe the rotating quark-gluon plasma. We present the relations for the drag force acting on the heavy quark both in the rotating- and static-at-infinity frames for arbitrary choice of the rotational parameters. We also calculate the thermal mass of a static quark in different frames and show that at high-T limit the dependence on rotation is suppressed

Exact holographic RG flows and the A1×A1A_{1}\times A_{1} Toda chain

latex, 55 pages, 34 figuresWe construct analytic solutions of Einstein gravity coupled to a dilaton field with a potential given by a sum of two exponentials, by rewriting the equations of motion in terms of an integrable Toda chain. Such solutions can be interpreted as domain walls interpolating between different asymptotics, and as such they can have interesting applications in holography. In some cases we can find flows that start from an AdS fixed point. We also find analytic black brane solutions at finite temperature. We discuss the properties of the solutions and the interpretation in terms of RG flow

Holographic drag force in 5d Kerr-AdS black hole

International audienceWe consider the 5d Kerr-AdS black hole as a gravity dual to rotating quark-gluon plasma. In the holographic prescription we calculate the drag force acting on a heavy quark. According to the holographic approach a heavy quark can be considered through the string in the gravity dual. We study the dynamics of the string for the Kerr-AdS backgrounds with one non-zero rotational parameter and two non-zero rotational parameters that are equal in magnitude. For the case of one non-zero rotational parameter we find good agreement with the prediction from the 4d case considered by arXiv:1012.3800