Related papers: Dynamical dark energy in the no-scale Brans-Dicke …
We discuss the possibility that dark energy arises from a strongly-coupled Higgs-Yang-Mills set of interacting fields in the non-perturbative regime. We choose the simplest $SU(2)$ representation, which is compatible with the Cosmological…
The role that the auxiliary scalar field $\phi$ played in Brans-Dicke cosmology is discussed. If a constant vacuum energy is assumed to be the origin of dark energy, then the corresponding density parameter would be a quantity varying with…
Brans--Dicke scalar--tensor theory provides a conformally coupling of the scalar field with gravity in Einstein's frame. This model is equivalent to an interacting quintessence in which dark matter is coupled to dark energy. This provides a…
In this paper it is shown that in non-minimally coupled Brans-Dicke theory containing a self-interacting potential, a suitable conformal transformation can automatically give rise to an interaction between the normal matter and the…
The observed dark energy in the universe might give particles inertial mass. We investigate one realization of this idea, that the dark energy field might be a decayed scalar component of a supermultiplet field in the early universe that…
In this work we perform some studies related to dark energy. Firstly, we propose a dynamical approach to explain the dark energy content of the universe. We assume that a massless scalar field couples to the Hubble parameter with some…
A global scale-invariant Dark Energy model based on Induced Gravity with the addition of a small $R^2$ contribution is examined. The scalar field (quintessence), playing the role of Dark Energy, has a quartic potential and generates…
The phenomenon of dark energy and its manifestations are studied in a spherically symmetric universe considering the Brans-Dicke scalar tensor theory. In the first model the dark energy behaves like a phantom type and in such a universe the…
We consider Brans-Dicke type nonminimally coupled scalar field as a candidate for dark energy. In the conformally transformed Einstein's frame, our model is similar to {\it coupled quintessence} model. In such models, we consider potentials…
We consider the Brans-Dicke theory motivated by the $f(R) = R + \alpha R^n - \beta R^{2-n}$ model to obtain a stable minimum of the Einstein frame scalar potential of the Brans-Dicke field. As a result we have obtained an inflationary…
The spontaneous symmetry breaking for the massless scalar field naturally arises from the framework of the effective theory (the non-minimal coupling of gravity to a scalar field). A magic key ingredient is to add the large vacuum energy…
If an ultraviolet fixed point renders quantum gravity renormalizable, the effective potential for a singlet scalar field -- the cosmon -- can be computed according to the corresponding scaling solution of the renormalization group…
Motivated by the work [K. Karami, J. Fehri, {{\it Phys. Lett. B}} {\bf 684}, 61 (2010)] and [A. Sheykhi, {{\it Phys. Lett. B}} {\bf 681}, 205 (2009)], we generalize their work to the new holographic dark energy model with…
We discuss some of the issues which we encounter when we try to invoke the scalar-tensor theories of gravitation as a theoretical basis of quintessence. One of the advantages of appealing to these theories is that they allow us to implement…
A linear relationship between the Hubble expansion parameter and the time derivative of the scalar field is explored in order to derive exact cosmological, attractor-like solutions, both in Einstein's theory and in Brans-Dicke gravity with…
We present a quintessence model for the dark energy in which the quintessence scalar field is produced by the decay of a super heavy dark matter and gradually condensate to a classical scalar field. This model can explain both the smallness…
It is very much intriguing if the Planck scale $M_{\rm{Pl}}$ is not a fundamental parameter. The Brans-Dicke gravity is nothing but the theory where the Planck scale $M_{\rm{Pl}}$ is indeed an illusional parameter. The theory predicts a…
We propose a scenario that can explain the early-time inflation and the late-time dark energy within a unified framework. A scalar potential combining power-law and exponential type in a context of extended Jordan-Brans-Dicke gravity is…
We present a new approach to quintessential inflation, in which both dark energy and inflation are explained by the evolution of a single scalar field. We start from a simple scalar potential with both oscillatory and exponential…
The Higgs mechanism is one of the central pieces of the Standard Model of electroweak interactions and thanks to it we can generate the masses of the elementary particles. Its fundamental origin is nonetheless unknown. Furthermore, in order…