Abstract
I present an exactly solvable quantum field theory in 0+1 dimensions in which a fermion field interacts with a boson field via a Yukawa coupling. The exact two-point Green's functions are constructed and compared with the Green's functions obtained from a ladder approximation to the Schwinger-Dyson equations. I find that the ladder approximation fails to produce even a qualitative agreement with the exact spectral function except in the weak-coupling limit.
- Received 18 October 1991
DOI:https://doi.org/10.1103/PhysRevD.46.1750
©1992 American Physical Society