Holographic thermalization with a chemical potential in Gauss-Bonnet gravity

Holographic thermalization is studied in the framework of Einstein-Maxwell-Gauss-Bonnet gravity. We use the two-point correlation function and expectation value of Wilson loop, which are dual to the renormalized geodesic length and minimal area surface in the bulk, to probe the thermalization. The numeric result shows that larger the Gauss-Bonnet coefficient is, shorter the thermalization time is, and larger the charge is, longer the thermalization time is, which implies that the Gauss-Bonnet coefficient can accelerate the thermalization while the charge has an opposite effect. In addition, we obtain the functions with respect to the thermalization time for both the thermalization probes at a fixed charge and Gauss-Bonnet coefficient, and on the basis of these functions, we obtain the thermalization velocity, which shows that the thermalization process is non-monotonic. At the middle and later periods of the thermalization process, we find that there is a phase transition point, which divides the thermalization into an acceleration phase and a deceleration phase. We also study the effect of the charge and Gauss-Bonnet coefficient on the phase transition point.Comment: 23 pages, many figures,footnote 4 is modified. arXiv admin note: substantial text overlap with arXiv:1305.484

Holographic thermalization in noncommutative geometry

Gravitational collapse of a shell of dust in noncommutative geometry is probed by the renormalized geodesic length, which is dual to probe the thermalization by the two-point correlation function in the dual conformal field theory. We find that larger the noncommutative parameter is, longer the thermalization time is, which implies that the large noncommutative parameter delays the thermalization process. We also investigate how the noncommutative parameter affects the thermalization velocity and thermalization acceleration.Comment: some materials have been delete

Charm-strange baryon strong decays in a chiral quark model

The strong decays of charm-strange baryons up to N=2 shell are studied in a chiral quark model. The theoretical predictions for the well determined charm-strange baryons, $\Xi_c^*(2645)$, $\Xi_c(2790)$ and $\Xi_c(2815)$, are in good agreement with the experimental data. This model is also extended to analyze the strong decays of the other newly observed charm-strange baryons $\Xi_c(2930)$, $\Xi_c(2980)$, $\Xi_c(3055)$, $\Xi_c(3080)$ and $\Xi_c(3123)$. Our predictions are given as follows. (i) $\Xi_c(2930)$ might be the first $P$-wave excitation of $\Xi_c'$ with $J^P=1/2^-$, favors the $|\Xi_c'\ ^2P_\lambda 1/2^->$or$|\Xi_c'\ ^4P_\lambda 1/2^->$state. (ii)$\Xi_c(2980)$might correspond to two overlapping$P$-wave states$|\Xi_c'\ ^2P_\rho 1/2^->$and$|\Xi_c'\ ^2P_\rho 3/2^->$, respectively. The$\Xi_c(2980)$observed in the$\Lambda_c^+\bar{K}\pi$final state is most likely to be the$|\Xi_c'\ ^2P_\rho 1/2^->$state, while the narrower resonance with a mass$m\simeq 2.97$GeV observed in the$\Xi_c^*(2645)\pi$channel favors to be assigned to the$|\Xi_c'\ ^2P_\rho 3/2^->$state. (iii)$\Xi_c(3080)$favors to be classified as the$|\Xi_c\ S_{\rho\rho} 1/2^+>$state, i.e., the first radial excitation (2S) of$\Xi_c$. (iv)$\Xi_c(3055)$is most likely to be the first$D$-wave excitation of$\Xi_c$with$J^P=3/2^+$, favors the$|\Xi_c\ ^2D_{\lambda\lambda} 3/2^+>$state. (v)$\Xi_c(3123)$might be assigned to the$|\Xi_c'\ ^4D_{\lambda\lambda} 3/2^+>$,$|\Xi_c'\ ^4D_{\lambda\lambda} 5/2^+>$, or$|\Xi_c\ ^2D_{\rho\rho} 5/2^+>$state. As a by-product, we calculate the strong decays of the bottom baryons$\Sigma_b^{\pm}$,$\Sigma_b^{*\pm}$and$\Xi_b^*$, which are in good agreement with the recent observations as well.Comment: 15 pages, 9 figure

Van der Waals-like phase transition from holographic entanglement entropy in Lorentz breaking massive gravity

In this paper, phase transition of AdS black holes in lorentz breaking massive gravity has been studied in the framework of holography. We find that there is a first order phase transition(FPT) and second order phase transition(SPT) both in Bekenstein-Hawking entropy(BHE)-temperature plane and holographic entanglement entropy(HEE)-temperature plane. Furthermore, for the FPT, the equal area law is checked and for the SPT, the critical exponent of the heat capacity is also computed. Our results confirm that the phase structure of HEE is similar to that of BHE in lorentz breaking massive gravity, which implies that HEE and BHE have some potential underlying relationship.Comment: 10 pages, 10 figure

Mutual correlation in the shock wave geometry

We probe the shock wave geometry with the mutual correlation in a spherically symmetric Reissner Nordstr\"om AdS black hole on the basis of the gauge/gravity duality. In the static background, we find that the regions living on the boundary of the AdS black holes are correlated provided the considered regions on the boundary are large enough. We also investigate the effect of the charge on the mutual correlation and find that the bigger the value of the charge is, the smaller the value of the mutual correlation will to be. As a small perturbation is added at the AdS boundary, the horizon shifts and a dynamical shock wave geometry forms after long time enough. In this dynamic background, we find that the greater the shift of the horizon is, the smaller the mutual correlation will to be. Especially for the case that the shift is large enough, the mutual correlation vanishes, which implies that the considered regions on the boundary are uncorrelated. The effect of the charge on the mutual correlation in this dynamic background is found to be the same as that in the static background.Comment: 10 page