Abstract

In a planar approximation to a Yukawa-type g psi * psi phi field theory with scalar fields psi and phi the author studies the Bethe-Salpeter (BS) equation for the scattering amplitude of the psi field in the case of vanishing psi wavefunction renormalisation constant Z2=O. Due to the asymptotic behaviour of the non-canonical Psi propagator, given by the corresponding Dyson-Schwinger equation for Z2=O, the Neumann series of the BS equation diverges for Euclidean values of the invariants and all masses m2, mu 2>O. Being responsible for this divergence, only the asymptotic part of the propagator is subsequently retained in the BS equation. Using in the Euclidean metric an exactly soluble high-energy version of the BS equation and treating the difference as a perturbation, he derives a new but equivalent integral equation for the scattering amplitude. By contraction-mapping arguments he obtains existence and multiplicity results for solutions of this transformed equation. The asymptotic behaviour of these solutions is rigorously established and found to be oscillating.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.