Two-Point Function Reduction of Four-Point Amputated Functions and Transformations in $F\bar{F}$ andRABasis in a Real-Time Finite Temperature NJL Model

Zhou Bang-Rong
2002 Communications in Theoretical Physics  
Based on a general analysis of Green functions in the real-time thermal field theory, we have proven that the four-point amputated functions in a NJL model in the fermion bubble diagram approximation behave like usual two-point functions. We expound the thermal transformations of the matrix propagator for a scalar bound state in the $F\bar{F}$ basis and in the $RA$ basis. The resulting physical causal, advanced and retarded propagator are respectively identical to corresponding ones derived in
more » ... ng ones derived in the imaginary-time formalism and this shows once again complete equivalence of the two formalisms of thermal field theory on the discussed problem in the NJL model.
doi:10.1088/0253-6102/37/6/685 fatcat:4i5ttntn4zcxtfvqza6itxat54