Universality in the relaxation dynamics of the composed black-hole-charged-massive-scalar-field system: The role of quantum Schwinger discharge

The quasinormal resonance spectrum {omega(n)(mu, q, M, Q)}(n=0)(n=infinity) of charged massive scalar fields in the charged Reissner-Nordstrom black-hole spacetime is studied analytically in the large-coupling regime. qQ >> M mu (here {mu, q} are respectively the mass and charge coupling constant of the field, and {M, Q} are respectively the mass and electric charge of the black hole). This physical system provides a striking illustration for the validity of the universal relaxation bound tau x T >= (h) over bar/pi in black-hole physics (here tau equivalent to 1/J omega(0) is the characteristic relaxation time of the composed black-hole-scalar-field system, and T is the Bekenstein-Hawking temperature of the black hole). In particular, it is shown that the relaxation dynamics of charged massive scalar fields in the charged Reissner-Nordstrom black-hole spacetime may saturate this quantum time-times-temperature inequality. Interestingly, we prove that potential violations of the bound by light scalar fields are excluded by the Schwinger-type pair-production mechanism (a vacuum polarization effect), a quantum phenomenon which restricts the physical parameters of the composed black-hole-charged-field system to the regime q Q << M-2 mu(2)/(h) over bar. (C) 2015 The Author. Published by Elsevier B.V.