Radiation Dominated Universe for Jordan-Brans-Dicke Cosmology

TL;DR

This paper demonstrates that Jordan-Brans-Dicke cosmology can replicate the radiation-dominated era of standard cosmology, ensuring consistent primordial nucleosynthesis results, and extends this to include a mass term for the scalar field to explain dark energy.

Contribution

It shows that Jordan-Brans-Dicke cosmology with a mass term can match standard radiation-dominated solutions and account for dark energy, maintaining nucleosynthesis consistency.

Findings

Jordan-Brans-Dicke cosmology matches standard radiation era

Primordial nucleosynthesis results are preserved

Mass term allows explanation of dark energy

Abstract

Jordan-Brans-Dicke cosmology with a standard kinetic term for the scalar field and no mass term has the same radiation dominated solution as standard Einstein cosmology without the cosmological constant. Because of this, the primordial nucleosynthesis (Big - Bang nucleosynthesis) result obtained for standard cosmology remains the same for Jordan-Brans-Dicke cosmology. We show that Jordan-Brans-Dicke cosmology with a mass term for the scalar field as well as explaining dark energy for the present era, can also explain radiation dominated cosmology for the primordial nucleosynthesis era.