Songbai Chen

Quasinormal modes of a black hole surrounded by quintessence

Using the third-order WKB approximation, we evaluate the quasinormal frequencies of massless scalar field perturbation around a black hole which is surrounded by static and spherically symmetric quintessence. Our result shows that due to the presence of quintessence, the scalar field damps more rapidly. Moreover, we also note that the quintessential state parameter (the ratio of pressure pq to the energy density ρq) plays an important role for the quasinormal frequencies. As the state parameter increases, so does the real part and the absolute value of the imaginary part decreases. This means that the scalar field decays more slowly in the larger quintessence case.

Asymptotic quasinormal modes of a coupled scalar field in the Garfinkle-Horowitz-Strominger dilaton spacetime

The analytic forms of the asymptotic quasinormal frequencies of a coupled scalar field in the Garfinkle-Horowitz-Strominger dilaton spacetime are investigated by using the monodromy technique proposed by Motl and Neitzke. It is found that the asymptotic quasinormal frequencies depend not only on the structure parameters of the background spacetime, but also on the coupling between the scalar fields and gravitational field. Moreover, our results show that only in the minimally coupled case, i.e., ξ tends to zero, the real parts of the asymptotic quasinormal frequencies agree with Hods conjecture, T H In 3.

Holographic superconductors in quintessence AdS black hole spacetime

We present a solution of Einstein equations describing a

Geodetic precession and strong gravitational lensing in dynamical Chern–Simons-modified gravity

d

Asymptotic quasinormal modes of a coupled scalar field in the Gibbons-Maeda dilaton spacetime

-dimensional planar quintessence AdS black hole which depends on the state parameter

A dark energy model interacting with dark matter and unparticle

w_q

Dirac quasinormal modes of the Garfinkle-Horowitz-Strominger dilaton black-hole spacetime

of quintessence. We investigate holographic superconductors in this background and probe effects of the state parameter

Phantom scalar emission in the Kerr black hole spacetime

w_q

Geometric optics for a coupling model of electromagnetic and gravitational fields

on the critical temperature

Gravitational field of a slowly rotating black hole with a phantom global monopole

T_c