Holographic study on the jet quenching parameter in anisotropic systems

We first calculate the jet quenching parameter of an anisotropic plasma with a U(1) chemical potential via the AdS/CFT duality. The effects of charge, anisotropy parameter and quark motion direction on the jet quenching parameter are investigated. We then discuss the situation of anisotropic black brane in the IR region. We study both the jet quenching parameters along the longitudinal direction and transverse plane

Black hole remnant in asymptotic Anti-de Sitter space

It is known that a solution of remnant were suggested for black hole ground state after surface gravity is corrected by loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic Anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking-Page phase transition. In this letter, we investigate the low temperature phase of three-dimensional BTZ black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored than the remnant solution at low temperature in three dimensions, while Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to be found in the overcooled phase if strings were present and its implication is discussed.Comment: 13 pages, 5 figures, submitted versio

Holographic QCD with Topologically Charged Domain-Wall/Membranes

We study the thermodynamical phase structures of holographic QCD with nontrivial topologically charged domain-wall/membranes which are originally related to the multiple $\theta$-vacua in the large $N_c$ limit. We realize the topologically charged membranes as the holographic D6-brane fluxes in the Sakai-Sugimoto model. The D6-brane fluxes couple to the probe D8-anti-D8 via Chern-Simon term, and act as the source for the baryonic current density of QCD. We find rich phase structures of the dual meson system by varying asymptotic separation of D8 and anti-D8. Especially, there can be a thermodynamically favored and stable phase of finite baryonic current density. This provides the supporting evidence for the discovery of the topologically charged membranes found in the lattice QCD calculations. We also find a crossover phase with the limiting baryonic current density and temperature which suggest a Hagedorn-like phase transition of meson dissociation.Comment: 23 pages, 19 figures;v2 typos corrected;v3 text improve

Globalization and Inequality: Evidence from Within China

In this paper, we provide a case study of the impact of globalization on income inequality using data across Chinese regions. The literature on cross-country studies has been criticized because differences in legal systems and other institutions across countries are difficult to control for, and the inequality data across countries may not be compatible. An in-depth case study of a particular country's experience can provide a useful complement to cross-country regressions. We construct a measure of urban-rural income ratio for 100 or so Chinese cities (urban areas and adjacent rural counties) over the period 1988-1993. The central finding is that cities that experience a greater degree of openness in trade also tend to demonstrate a greater decline in urban-rural income inequality. Thus, globalization has helped to reduce, rather than increase, the urban-rural income inequality. This pattern in the data suggests that inferences based solely on China's national aggregate figures (overall openness and overall inequality) can be misleading. The negative association between openness and inequality holds up when we apply a geography-based instrumental variable approach to correct for possible endogeneity of a region's trade openness.