|
Abstract
|
A generalized version for the Rastall theory is
proposed showing the agreement with the cosmic accelerating
expansion. In this regard, a coupling between geometry
and the pressureless matter fields is derived which may play
the role of dark energy, responsible for the current accelerating
expansion phase. Moreover, our study also shows that
the radiation field may not be coupled to the geometry in a
non-minimal way which represents that the ordinary energymomentum
conservation law is respected by the radiation
source. It is also shown that the primary inflationary era may
be justified by the ability of the geometry to couple to the
energy-momentum source in an empty flat FRW universe. In
fact, this ability is independent of the existence of the energymomentum
source and may compel the empty flat FRW universe
to expand exponentially. Finally, we consider a flat
FRW universe field by a spatially homogeneous scalar field
evolving in potential V(φ), and study the results of applying
the slow-roll approximation to the system which may lead to
an inflationary phase for the universe expansion
|