Scalar-Fermion Interaction as the Driver of Cosmic Acceleration

TL;DR

This paper proposes a scalar-fermion interaction model of Yukawa type within General Relativity that explains cosmic acceleration, supported by observational data and a generalized Om(z) parameter analysis.

Contribution

It introduces a novel scalar-fermion interaction framework to account for cosmic acceleration and provides a unified model of cosmic expansion history validated by data.

Findings

Scalar-fermion interaction drives cosmic acceleration.

Model fits observational data well.

Universe exhibits multiple transition epochs.

Abstract

We argue that an interacting scalar-fermion distribution can be used to demonstrate the cosmic acceleration in General Relativity. The interaction is of Yukawa nature and it drives the fermion density to decay with cosmic time. The consistency of the model is established through, (a) a generalization of the Om(z) parameter, the present matter density contrast of the universe, and (b) a comparison of theoretical results with observational data, using a Markov Chain Monte Carlo code. A simple model of unified cosmic expansion history is also discussed. There are more than one instances where the universe goes through a transition between subsequent epochs with different patterns of cosmic expansion. These patterns impose some constraints on the scalar-fermion interaction profile and on the overall cosmological dynamics.