Related papers: Teleparallel Dark Energy with Purely Non-minimal C…
An overview is presented of a recently proposed "radically conservative" solution to the problem of dark energy in cosmology. The proposal yields a model universe which appears to be quantitatively viable, in terms of its fit to supernovae…
We study the cosmological evolution of an induced gravity model with a scale symmetry breaking potential for the scalar field. The radiation to matter transition, following inflation and reheating, influences the dynamics of such a field…
In the present work, we adopt a nonlinear scalar field theory coupled to the gravity sector to model galactic dark matter. We found analytical solutions for the scalar field coupled to gravity in the Newtonian limit, assuming an isotropic…
Dark energy models with a single scalar field cannot cross the equation of state divide set by a cosmological constant. More general models that allow crossing require additional degrees of freedom to ensure gravitational stability. We show…
We examine the embedding of dark energy in high energy models based upon supergravity and extend the usual phenomenological setting comprising an observable sector and a hidden supersymmetry breaking sector by including a third sector…
Any non-gravitational coupling between dark matter and dark energy modifies the cosmological dynamics. Interactions in the dark sector are considered to be relevant to address the coincidence problem. Moreover, in various models the…
In light of the cosmological observations, we investigate dark energy models from the Horndeski theory of gravity. In particular, we consider cosmological models with the derivative self-interaction of the scalar field and the derivative…
The $f(T,T_G)$ class of gravitational modification, based on the quadratic torsion scalar $T$, as well as on the new quartic torsion scalar $T_G$ which is the teleparallel equivalent of the Gauss-Bonnet term, is a novel theory, different…
Within our recent thermodynamic model of gravity the dark energy is identified with the energy of collective gravitational interactions of all particles in the universe, which is missing in the standard treatments. For a simple model…
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…
In this work we aim to revive the interest for non-minimal derivative coupling theories of gravity, in light of the GW170817 event. These theories include a string motivated non-minimal kinetic term for the scalar field of the form $\sim…
In this work, we first discuss the possibility that dark energy models with negative energy density values in the past can alleviate the $H_0$ tension, as well as the discrepancy with the baryon acoustic oscillation (BAO) Lyman-$\alpha$…
We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…
The hypothesis is rapidly gaining popularity that the dark energy pervading our universe is extra-repulsive ($-p>\rho$). The density of such a substance(usually called phantom energy) grows with the cosmological expansion and may become…
We consider the oscillating dark energy with periodic equation of state in two equivalent formulations: ideal fluid or scalar-tensor theory. It is shown that such dark energy suggests the natural way for the unification of early-time…
We consider a supersymmetric model of dark energy coupled to cold dark matter: the supersymmetron. In the absence of cold dark matter, the supersymmetron converges to a supersymmetric minimum with a vanishing cosmological constant. When…
We study the nonminimally coupled complex scalar field within the framework of teleparallel gravity. Coupling of the field nonminimally to the torsion scalar destroys the Lorentz invariance of the theory in the sense that the resulting…
A cosmic potential which can relax the vacuum energy is proposed in a framework of scalar-tensor gravity. In the phase of the gravity scalar field around the evolution with an approximate emergent conformal symmetry, we have obtained a set…
We derive the one-loop perturbation kernels for a minimal modified gravity model in which dark energy is coupled to dark matter via a constant coupling. We derive the time-dependent kernels via analytical and numerical solutions and provide…
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…