Sang-Jin Sin

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We determine the structure of the hydrodynamics with conserved current, using the gauge/ gravity duality of charged black-hole background. It turns out that even in the presence of the external electromagnetic field at the boundary, bulk Einstein equation is equivalent to the boundary conservation of energy momentum tensor and that of current. As a(More)
We consider a gravity dual description of time dependent, strongly interacting large-N c N = 4 SYM. We regard the gauge theory system as a fluid with shear viscosity. Our fluid is expanding in one direction following the Bjorken's picture that is relevant to RHIC experiments. We obtain the dual geometry at the late time that is consistent with dissipative(More)
We study the non-linear propagation of radiation in N=4 SYM at zero and finite temperature using the refined radius/scale duality in AdS/CFT. We argue that a pulse radiation by a quark at the boundary should be described holographically by a " point like object " passing through the center of the AdS bulk. We find that at finite temperature, the radiation(More)
We show that the D-instanton in the AdS 5 × S 5 background is a wormhole connecting the background AdS 5 × S 5 to the flat space R 10 located at the position of the D-instanton. By a SL(2, R) rotation of type IIB theory, we can make the global geometry flat in string frame. We also find that, due to the tight relation between the dilaton and the axion,(More)
In the context of the AdS/CFT correspondence we discuss the gravity dual of a heavy-ion-like collision in a variant of N = 4 SYM. We provide a gravity dual picture of entire process. We estimate the initial entropy and temperature as a function of the initial saturation momentum Q s. We suggest that the cooling of the fireball is the dual of a brane(More)
We consider a holographic dual of hydrodynamics of N = 4 SYM plasma that undergoes non-isotropic three-dimensional expansion relevant to RHIC fireball. Our model is a natural extension of the Bjorken's one-dimensional expansion, and it describes an elliptic flow whose v 2 and eccentricity are given in terms of anisotropy parameters. Holographic(More)
In the context of holographic QCD we analyze Sakai-Sugimoto's chiral model at finite baryon density and zero temperature. The baryon number density is introduced through compact D4 wrapping S 4 at the tip of D8-D8. Each baryon acts as a chiral point-like source distributed uniformly over R 3 , and leads a non-vanishing U (1) V potential on the brane. For(More)
We provide a method to study hadronic matter at finite density in the context of the Sakai-Sugimoto model. We introduce the baryon chemical potential through the external U (1) v in the induced (DBI plus CS) action on the D8-probe-brane, where baryons are skyrmions. Vector dominance is manifest at finite density. We derive the baryon density effect on the(More)
We consider quadratic fluctuations around the tachyon vacuum numerically in open string field theory. We work on a space H vac N spanned by basis string states used in the Schnabl's vacuum solution. We show that the truncated form of the Schnabl's vacuum solution on H vac N is well-behaved in numerical work. The orthogonal basis for the new BRST operator˜Q(More)