Chen Ju-Hua

Geodetic Precession in Schwarzschild Spacetime Surrounded by Quintessence

We investigate the geodetic precession of light in the Schwarzschild spacetime surrounded by quintessence. With the analysis and numerical methods, we find that the geodetic precession of light in the Schwarzschild spacetime surrounded by quintessence increases when the normalization factor c increases, and the geodetic precession decreases when the quintessential state parameter ωq increases.

Quasinormal modes of the scalar field in five-dimensional Lovelock black hole spacetime

In this paper, using the third-order WKB approximation, we investigate the quasinormal frequencies of the scalar field in the background of a five-dimensional Lovelock black hole. We find that the ultraviolet correction to Einstein theory in the Lovelock theory makes the scalar field decay more slowly and oscillate more quickly, and the cosmological constant makes the scalar field decay more slowly and oscillate more slowly in the Lovelock black hole background.In this paper, using the third-order WKB approximation, we investigate the quasinormal frequencies of the scalar field in the background of a five-dimensional Lovelock black hole. We find that the ultraviolet correction to Einstein theory in the Lovelock theory makes the scalar field decay more slowly and oscillate more quickly, and the cosmological constant makes the scalar field decay more slowly and oscillate more slowly in the Lovelock black hole background.

Absorption of a massless scalar wave from a Schwarzschild black hole surrounded by quintessence

By using the partial wave method, we investigate the absorption of a massless scalar wave from a Schwarzschild black hole surrounded by quintessence. We obtained the expression of absorption cross section Then we numerically carry out the absorption cross section and we find that the larger the angular momentum quantum number l is, the smaller the corresponding maximum value of the partial absorption cross section is, and that the total absorption cross section tends to the geometric-optical limit σhfabs ≈ πb2c. We also find that higher value of ωq (state parameter of quintessence) corresponds to the higher value of absorption cross section σabs.

Influence of dark energy on time-like geodesic motion in Schwarzschild spacetime

In this paper we investigate the influence of the dark energy on the time-like geodesic motion of a particle in Schwarzschild spacetime by analysing the behaviour of the effective potential which appears in an equation of motion. For the non-radial time-like geodesics, we find a bound orbit when the particle energy is in an appropriate range, and also find another possible orbit, which is that the particle drops straightly into the singularity of a black hole or escapes to infinity. For the radial time-like geodesics, we find an unstable circular orbit when the particle energy is the critical value, in which case it is possible for the particle to escape to infinity.

Absorption/Scattering of Massless Dirac Wave from Black Hole Spacetimes with Cosmic String

In this paper we investigate the scattering of massless Dirac wave from several different black hole spacetimes (i.e. the Schwarzschild black hole, the RN extremal black hole, the Schwarzschild de Sitter black hole, and the extremal Schwarzschild de Sitter black hole) which are influenced by the cosmic string, respectively. All these cases show us that the total absorption cross sections oscillate around the geometric-optical limit and decrease with linear mass density μ of the cosmic string. All of the total scattering cross sections exhibit that the main scattering angle becomes narrower for the high partial frequency wave. Due to the influence of cosmic string, the glory peak becomes wider for larger values of linear mass density μ of the cosmic string.

Absorption cross section of black holes with global monopole

We study the absorption problem for a massless scalar field propagating in general static spherically-symmetric black holes with a global monopole. The absorption cross section expression is provided using a partial-wave method, which permits us to make an elegant and powerful resummation of the absorption cross section, and to extract the physical information encoded in the sum over the partial-wave contributions.

Gravitational frequency-shift and deflection of light by quintessence

In this paper we investigate the gravitational frequency-shift and deflection of light in the Schwarzschild black hole space-time surrounded by quintessence. With the analytical and numerical methods, we find that the gravitational frequency-shift of light in the Schwarzschild black hole space-time surrounded by the quintessence increases as the values of the normalization factor c increases, but the gravitational frequency-shift of light decreases with the quintessential state parameter ωq increasing. We also calculate the deflection of light by quintessence and find that the deflection rate decreases as the values of the quintessential parameters c and ωq increase.

Chaos feature of test particle in the gravitational field with a quadrupole

In this paper we investigate the dynamics of a test particle in the gravitational field with a quadrupole. By constructing Poincare sections for different values of the parameters and initial conditions, we find a chaotic evolution. From these Poincare sections, we further confirm that the chaotic evolution of the test particle originates from the quadrupole.

Chaos in Bianchi I cosmology

We have investigated the dynamical evolution of the Yang–Mills (YM) field in Bianchi I cosmology background. We find that the long-time evolution behaviour of the YM field is highly sensitive to initial conditions, i.e. small fluctuations of initial conditions for fixed Hamiltonian of the system may rapidly change the evolution of the field. By using the Poincare section method, we further illustrate that the dynamical evolution of the YM field in Bianchi I cosmology background has certain typically chaotic properties.

Time-Like Geodesic Motion in Schwarzschild Spacetime with Weak-Field Limit

We analyze the geodesic motion in Schwarzschild spacetime with the weak-field limit. We investigate all geodesic types of the test particle by solving the geodesic equation and analyzing the behavior of effective potential. At the same time, all kinds of orbits, which are allowed according to the energy level corresponding to the effective potential, are numerically simulated in detail. Then we discuss the effect of different parameters on the effective potential energy. We also find that the test particle falls rapidly along the fall-into orbit and the radius of stable (unstable) circular orbits become larger in the Schwarzschild spacetime with the weak-field limit than those in the Schwarzschild case.