https://doi.org/10.1140/epjc/s10052-017-4877-7
Regular Article - Theoretical Physics
History of cosmic evolution with modified Gauss–Bonnet-dilatonic coupled term
1
Department of Physics, Jangipur College, Murshidabad, 742213, India
2
Department of Physics, Ramananda Centenary College, Purulia, 723151, India
3
Department of Physics, University of Kalyani, Nadia, 741235, India
* e-mail: sanyal_ak@yahoo.com
Received:
16
August
2016
Accepted:
28
April
2017
Published online:
18
May
2017
Gauss–Bonnet-dilatonic coupling in four dimensions plays an important role to explain late-time cosmic evolution. However, this term is an outcome of the low energy string effective action and thus ought to be important in the early universe too. Unfortunately, a phase-space formulation of such a theory does not exist in the literature due to branching. We therefore consider a modified theory of gravity, which contains a nonminimally coupled scalar–tensor sector in addition to a higher-order scalar curvature invariant term with Gauss–Bonnet-dilatonic coupling. Such an action unifies early inflation with late-time cosmic acceleration. The quantum version of the theory is also well behaved.
© The Author(s), 2017
