Collision Of Particles And Quasinormal Modes Of A Coupled Scalar Field In The Black Hole Spacetimes

Quasinormal modes and collision of particles in the black hole spacetimes have been attractive subjects in the black hole physics and astrophysics for many years. As the characteristics sound of black holes, quasinormal modes could be regarded as a direct way to identify the existence of black holes, which would be detected from the experiments of gravitational waves in the near future. It is widely believed that quasinormal modes have close connection with the AdS/CFT correspondence and loop quantum gravity. The BSW mechanism show that the center-of-mass(CM) energy for particles colliding in the black hole spacetimes tends to be arbitrarily high near the event horizon, which means that the black holes could act as the Planck-energy-scale paticle accelerators and one could explore the signal of ultra-high energy physics by this mechanism. Therefor, it is of great importance to investigate the quasinormal modes and collision of particles in the black holes. In this thesis, we chiefly study the quasinormal modes of a scalar perturbation coupling with Einstein’s tensor in the background of the warped AdS3black hole spacetime and the collision of particles in the accelerating and rotating black hole spacetime.In chapter1, we present a brief introduction of quasinormal modes and the collision of paticles in the black holes.In chapter2, we study the quasinormal modes of a massive scalar field coupling to Einstein’s tensor in the spacelike stretched AdS3black hole spacetime. Our results show that both the right-moving and left-moving quasinormal frequencies depend not only on the warped parameter v of black hole, but also on the coupling between the-scalar field and Einstein’s tensor. When υ～1, both the imaginary parts of ωR and ωL increase with77for fixed v. When the parameter v is larger than1, both the imaginary parts decreases with η. Moreover, one can find that there exists the growing modes for ωR and ωL, which means that the scalar perturbations grow exponentially and then the black hole is unstable in this case. We also probe the effects of the coupling on the left and right conformal weights hL and hR of the operators dual to the scalar field in the boundary and check further the warped AdS/CFT correspondence.In chapter3, we study the collision of two geodesic particles in the accelerating and rotating black hole spacetime and probe the effects of the acceleration of black hole on the center-of-mass energy of the colliding particles and on the high-velocity collision belts. We find that the dependence of the center-of-mass energy on the acceleration in the near event-horizon collision is different from that in the near acceleration-horizon case. For the particles moving in the equatorial plane, the CM energy EcmA in the near acceleration-horizon collision is affected by α, but the CM energy EcmH in the near event-horizon collision is independent of the acceleration of the black hole. In addition, the unbound CM energy can be obtained in the near event-horizon collision, but it is impossible to obtain in the near acceleration-horizon collision. Moreover, the presence of the acceleration changes the shape and position of the high-velocity collision belts. Our results show that the acceleration of black holes brings richer physics for the collision of particles.Finally, we give a summary and a outlook of quasinormal modes and particle collision.