Jets in a strongly coupled anisotropic plasma

In this paper, we study the dynamics of the light quark jet moving through the static, strongly coupled $\mathcal{N}=4$, anisotropic plasma with and without charge. The light quark is presented by a point-like initial condition falling string in the context of the AdS/CFT. We calculate the stopping distance of the light quark in the anisotropic medium and compare it with its isotropic value. By studying the falling string in the beam direction and transverse direction, we find that the jet quenching increases in both directions. Although, the enhancement of quenching is larger in the beam direction. Also, the suppression of stopping distance is more prominent when the anisotropic plasma have the same temperature as the isotropic plasma.Comment: Minor misprints corrected, some references added, and some figures change

The cosmic QCD phase transition with dense matter and its gravitational waves from holography

Consistent with cosmological constraints, there are scenarios with the large lepton asymmetry which can lead to the finite baryochemical potential at the cosmic QCD phase transition scale. In this paper, we investigate this possibility in the holographic models. Using the holographic renormalization method, we find the first order Hawking-Page phase transition, between Reissner-Nordstr$\rm\ddot{o}$m AdS black hole and thermal charged AdS space, corresponding to the de/confinement phase transition. We obtain the gravitational wave spectra generated during the evolution of bubbles for a range of the bubble wall velocity and examine the reliability of the scenarios and consequent calculations by gravitational wave experiments.Comment: 18 pages , 4 figures, references and new discussions added, accepted to be published in Phys. Lett.

Entropic destruction of a moving heavy quarkonium

Recently it has been shown that the peak of the quarkonium entropy at the deconfinement transition is related to the emergent entropic force which destructs the quarkonium. Using the AdS/CFT correspondence, we consider dissociation of a moving heavy quarkonium by entropic force. We find that the entropic force destructs the moving quarkonium easier than the static case which is expected from perturbative weakly coupled plasma. By considering the Maxwell charge, we study the effect of medium on the destruction of heavy quarkonium. It is shown that the quarkonium dissociates easier in the medium.Comment: 10 pages, 8 figure

Linearized Holographic Isotropization at Finite Coupling

We study holographic isotropization of an anisotropic homogeneous non-Abelian strongly coupled plasma in the presence of Gauss-Bonnet corrections. It was verified before that one can linearize Einstein's equations around the final black hole background and simplify the complicated setup. Using this approach, we study the expectation value of the boundary stress tensor. Although we consider small values of the Gauss-Bonnet coupling constant, it is found that finite coupling leads to significant increasing of the thermalization time. By including higher order corrections in linearization, we extend the results to study the effect of the Gauss-Bonnet coupling on the entropy production on the event horizon.Comment: V2 and v3 are the same! version 4 is ne

Towards a holographic quark-hadron continuity

We study dense nuclear and quark matter within a single microscopic approach, namely the holographic Sakai-Sugimoto model. Nuclear matter is described via instantons in the bulk, and we show that instanton interactions are crucial for a continuous connection of chirally broken and chirally symmetric phases. The continuous path from nuclear to quark matter includes metastable and unstable stationary points of the potential, while the actual chiral phase transition remains of first order, as in earlier approximations. We show that the model parameters can be chosen to reproduce low-density properties of nuclear matter and observe a non-monotonic behavior of the speed of sound as a function of the baryon chemical potential, as suggested by constraints from QCD and astrophysics.Comment: 28+19 pages, 5 figures; v2: clarifications and references added, version to appear in JHE

Conductivity at finite 't Hooft coupling from AdS/CFT

We use the AdS/CFT correspondence to study the DC conductivity of massive $\mathcal{N} = 2$ hypermultiplet fields in an $\mathcal{N} = 4\, SU(N_c)$ super-Yang-Mills theory plasma in the large $N_c$ and finite 't Hooft coupling. We also discuss general curvature-squared and Gauss-Bonnet corrections on the DC conductivity.Comment: 18 pages, 8figure

The Imaginary Part of the Static Potential in Strongly Coupled Anisotropic Plasma

Using the gauge/gravity duality we study the imaginary part of the static potential associated to the thermal width in finite temperature strongly coupled anisotropic plasma. We firstly derive the potential for a generic anisotropic background. Then we apply our formulas to a theory where the anisotropy has been generated by a space dependent axion term. We find that using our method there exist a peculiar turning point in the imaginary part of the potential, similar to the one appearing in the real part. The presence of anisotropy leads to decrease of the imaginary potential, where larger decrease happens along the anisotropic direction when the temperature is kept fixed. When the entropy density is fixed, increase happens along the parallel direction while along the transverse plane we observe a decrease. To estimate the thermal width we use an approximate extrapolation beyond the turning point and we find a decrease in presence of the anisotropy, independently of the comparison scheme used.Comment: 20+4 pages, 15 figures, v2: version published in JHE