Abstract :
Starting from the Frolov–Zelʹnikov stress-energy tensor of quantum massive fields in the Schwarzschild background, we recover the contribution Sq of these field into the entropy of a black hole. For fermions with the spin s=1/2 Sq>0, for scalar fields Sq>0 provided the coupling parameter is restricted to some interval, and Sq<0 for vector fields. The appearance of negative values of Sq is attributed to the fact that in the situation under discussion there are no real quanta to contribute to the entropy, so Sq is due to vacuum polarization entirely and has nothing to do with the statistical–mechanical entropy. We also consider the spacetime with an acceleration horizon — the Bertotti–Robison spacetime — and show that Sq=0 for massive fields similarly to what was proved earlier for massless fields.
