Slowly decaying resonances of charged massive scalar fields in the Reissner-Nordstrom black-hole spacetime

We determine the characteristic timescales associated with the linearized relaxation dynamics of the composed Reissner-Nordstrom-black-hole-charged-massive-scalar-field system. To that end, the quasinormal resonant frequencies {omega(n)(mu, q, M, Q)}(n=0)(n=8) which characterize the dynamics of a charged scalar field of mass mu and charge coupling constant q in the charged Reissner-Nordstrom black-hole spacetime of mass M and electric charge Q are determined analytically in the eikonal regime 1 << M mu < qQ. Interestingly, we find that, for a given value of the dimensionless black-hole electric charge Q/M, the imaginary part of the resonant oscillation frequency is a monotonically decreasing function of the dimensionless ratio mu/q. In particular, it is shown that the quasinormal resonance spectrum is characterized by the asymptotic behavior J omega -> 0 in the limiting case M mu -> qQ. This intriguing finding implies that the composed Reissner-Nordstrom-black-hole-charged-massive-scalar-field system is characterized by extremely long relaxation times tau(relax) equivalent to 1/J omega -> infinity in the M mu/qQ -> 1(-) limit. (C) 2016 The Author(s). Published by Elsevier B.V.