Cosmological Evolution Dynamics and Om(z) Diagnostic in a Scalar–fermion Model With a Generalized Scale Factor

A cosmological model of an expanding Universe with scalar–fermion interactions is considered.Our model is based on the interaction of scalar and fermion fields via a Yukawa-type coupling, which influences the development of cosmological expansion in its late stages. The generalized scale factor is used to study the evolution and dynamics of the system. This approach allows us to explore various expansion regimes and analyze the contribution of fields, namely, the scalar and fermion components, to the total energy density and pressure. The viability of the cosmological evolution model is studied using the dimensionless Hubble parameter and the Om(z) diagnostic.The behavior obtained differs from the standard case, where the parameter remains constant. Our results show that the effective component of dark energy dynamically evolves as the Universe expands. Our analysis demonstrates that the interaction of scalar and fermion fields can significantly influence the history and evolution of the expansion and lead to stable cosmological behavior. The proposed model can be used for further studies of dark energy interaction scenarios.