Field Perturbation Of The Brane World Gravity System And Stability

This thesis comprises two topics in the realm of high energy physics in the brane-world scenario. The first topic concerns the detection of probable extra dimensions of our universe, where the absorption and emission spectra of scalar particles and gravitons of a brane-world black hole are studied. The results are different from those of the classical 4D Schwarzschild black hole, which reveals the signatures of the extra-dimensions on the 4D brane. The second topic concerns the stability of black strings. The stability analysis is carried out on a BTZ black string under Fermionic and gravitational perturbations. Unstable quasi-normal modes are discovered as the proof to the dynamical instability of the BTZ black string. This dynamical instability matches the thermodynamical prediction of the instability of BTZ strings.