  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.
