Interaction of massless minimally coupled scalar field with spinor field in de Sitter universe

TL;DR

This paper investigates how a massless minimally coupled scalar field interacts with spinor fields in de Sitter space and how this interaction diminishes in the flat Minkowski limit, highlighting the curvature dependence of the scalar field.

Contribution

It demonstrates that the interaction between the scalar and spinor fields vanishes in the Minkowski limit, emphasizing the curvature-dependent nature of the scalar field.

Findings

Interaction and scattering matrix become zero in Minkowski limit.

Incoming and outgoing spinor fields are identical in null curvature limit.

Massless minimally coupled scalar field depends on spacetime curvature.

Abstract

The interaction of massless minimally coupled scalar field and spinor field $ \left( \Psi + \Phi_m \rightarrow \Psi + \Phi_m \right) $ is investigated and the behavior of interaction and scattering matrix in Minkowski limit is studied. It is seen that the massless minimally coupled scalar field operator, the interaction Lagrangian and the scattering matrix become zero. Also the incoming and outgoing spinor fields, which in de Sitter space-time are different and are interacted with massless minimally coupled scalar field, in null curvature limit are the same and no interaction seen. In other word, the massless minimally coupled scalar field is dependent on curvature and can be considered as a part of a gravitational field.