Spectroscopy from the d-dimensional Reissner–Nordström black hole via adiabatic covariant action

Via modified adiabatic invariant I=∮p_i dq_i, we investigate the area spectrum of the d-dimensional Reissner–Nordström black hole in two different coordinate frames. Emphasis is given to covariance of the results. The equally spaced spectroscopy is always given by $\Delta A=8\pi l_{P}^{2}$, which confirms the initial proposal of Bekenstein. Additionally, it is noteworthy that how we derived the spectroscopy does not need the small charge limit in contrast to the quasinormal mode analysis.