Quasinormal modes of a Schwarzschild black hole surrounded by free static spherically symmetric quintessence: Electromagnetic perturbations

In this paper, we evaluated the quasinormal modes of electromagnetic perturbation in a Schwarzschild black hole surrounded by the static spherically symmetric quintessence by using the third-order WKB approximation when the quintessential state parameter $w_q$ in the range of $-1\mathrm{/}3<w_q<0$. Due to the presence of quintessence, Maxwell field damps more slowly. And when at $-1<w_q<-1\mathrm{/}3$, it is similar to the black hole solution in the ds/Ads spacetime. The appropriate boundary conditions need to be modified.