Quasinormal modes of the bumblebee black holes with a global monopole

Abstract: We compute quasinormal modes of test fields around spherically symmetric black holes with a global monopole in bumblebee gravity. The frequency of oscillation and the damping rate exhibit significant decreasing as the global monopole parameter is increased. An intriguing observation arises in the extreme limit, where the quasinormal modes manifest a form of universal behavior: the actual oscillation frequency remains unaltered despite variations in the Lorentz symmetry breaking (LSB) parameter. Our calculations are conducted through two distinct methods, both of which yield results that align remarkably well. Furthermore, we derive an analytical formula for quasinormal modes within the eikonal approximation and beyond it. In the limits of either vanishing deficit angle or bumblebee parameters, the compact and sufficiently accurate analytic expressions for quasinormal modes are obtained.