Stress-energy tensor of neutral massive fields in Reissner-Nordström spacetime

The approximation of the renormalized stress-energy tensor of the quantized massive scalar, spinor, and vector field in Reissner-Nordstr\"om spacetime is constructed. It is achieved by functional differentiation of the lowest order of the Schwinger-DeWitt effective action involving the coincidence limit of the Hadamard-Minakshisundaram-DeWitt-Seely coefficient a₃, and restricting the thus obtained general formulas to spacetimes with a vanishing curvature scalar. For the massive scalar field with an arbitrary curvature coupling, our results reproduce those obtained previously by Anderson, Hiscock, and Samuel by means of a sixth-order WKB approximation.