Ratio of absorption cross section for Dirac fermion to that for scalar in the higher-dimensional black hole background

摘要

The ratio of the low-energy absorption cross section for Dirac fermion tothat for minimally coupled scalar is computed when the spacetimes are varioustypes of the higher-dimensional Reissner-Nordstr\"{o}m black holes. It is foundthat the low-energy absorption cross sections for the Dirac fermion always goesto zero in the extremal limit regardless of the detailed geometry of thespacetime. The physical importance of our results is discussed in the contextof the brane-world scenarios and string theories.