On Holographic Dual of the Dyonic Reissner-Nordstr\"om Black Hole

It is shown that the hidden conformal symmetry, namely $SO(2,2) \sim SL(2,R)_L \times SL(2,R)_R$ symmetry, of the non-extremal dyonic Reissner-Nordstr"om black hole can be probed by a charged massless scalar field at low frequencies. The existence of such hidden conformal symmetry suggests that the field theory holographically dual to the 4D Reissner-Nordstr"om black hole indeed should be a 2D CFT. Although the associated AdS${}_3$ structure does not explicitly appear in the near horizon geometry, the primary parameters of the dual CFT${}_2$ can be exactly obtained without the necessity of embedding the 4D Reissner-Nordstr"om black hole into 5D spacetime. The duality is further supported by comparing the absorption cross sections and real-time correlators obtained from both the CFT and the gravity sides.