Decay of charged fields in de Sitter spacetime

We study the decay of charged scalar and spinor fields around Reissner-Nordstrom black holes in de Sitter spacetime through calculations of quasi-normal frequencies of the fields. The influence of the parameters of the black hole (charge, mass), of the decaying fields (charge, spin) and of the spacetime (cosmological constant) on the decay is analysed. The analytic formula for the calculation of quasi-normal frequencies for a large multipole number (eikonal approximation) is derived both for the spinor and scalar fields.