Stress-energy tensor of quantized scalar fields in static black hole spacetimes

We present a method for the numerical computation of the stress-energy tensor of a quantized scalar field in a general static spherically symmetric spacetime, with or without horizon. The scalar field may have arbitrary curvature coupling and mass. Our method leads in a natural way to a new analytic approximation to the stress-energy tensor for massless scalar fields in these spacetimes. We use the results to compute stress-energy tensors of quantized scalar fields in Schwarzschild and Reissner-Norstro/m black hole spacetimes.