The entropies of scalar field and neutrino field are calculated in the background of three-dimensional BTZ black hole. Considering statistical physics,we propose not to consider the superraradiant modes for bosons (Fermion fields do not display supperradiance).In fact,the nonsuperradiant modes do contribute exactly the area entropy for both bosons and fermions. The result shows that the neutrino field entropy is 3/2 times the scalar one.
GAO Changjun1,2 & SHEN Yougen1,2,3,4 1.Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China(mailing address)