Based on the idea that the components of a cosmological metric may be
determined by the total gravitational potential of the universe, the scalar
field {\phi} = 1/G in the Jordan-Brans-Dicke (JBD) theory is introduced as
evolving with the inverse square of the scale factor. Since the gravitational
potential is related to the field {\phi} resulting from Mach principle and
depends on time due to the expansion of space, this temporal evolution of the
field should be in accord with the evolution of time and space intervals in the
metric tensor. For the same reason, the time dependence of the field makes
these comoving intervals relative for different points on the time axis. Thus,
it has been shown that introduction of the cosmic gravitational potential as a
time dependent scalar field which decreases with 1/a2 in the
coordinate-transformed Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime,
may resolve flatness, horizon and late-time accelerating expansion problems in
the standard model of cosmology. The luminosity distance vs redshift data of
Type Ia supernovae is in agreement with this approach.Comment: 7 page