FERMION FIELDS IN ETA-XI SPACETIME

Fermion fields in eta-zeta spacetime are discussed. By the path-integral formulation of quantum field theory, we show that the (zero-temperature) Green's functions for Dirac fields on the Euclidean section in eta-zeta spacetime are equal to the imaginary-time thermal Green's functions in Minkowski spacetime, and that the (zero-temperature) Green's functions on the Lorentzian section in eta-zeta spacetime correspond to the real-time thermal Green's functions in Minkowski spacetime. The antiperiodicity of fermion fields in eta-zeta spacetime originates from Lorentz transformation properties of the fields.