Related papers: Dark energy evolution from quantum gravity
Recent cosmological observations suggest that nearly seventy per cent of the energy density in the universe is unclustered and has negative pressure. Several conceptual issues related to the modeling of this component (`dark energy'), which…
In this review, I discuss briefly how the presence of a cosmological constant in the Universe may imply a decoherent evolution of quantum matter in it, and as a consequence a fundamental irreversibility of time unrelated in principle to CP…
Dynamical vacuum energy or quintessence, a slowly varying and spatially inhomogeneous component of the energy density with negative pressure, is currently consistent with the observational data. One potential difficulty with the idea of…
The solution of dark energy problem in the models without scalars is presented. It is shown that late-time accelerating cosmology may be generated by the ideal fluid with some implicit equation of state. The universe evolution within…
We investigate cosmological models in which dynamical dark energy consists of a scalar field whose present-day value is controlled by a coupling to the neutrino sector. The behaviour of the scalar field depends on three functions: a kinetic…
It was recently suggested (arxiv:2410.06604) that the small value of the dark energy of the universe could be explained in terms of the scale of neutrino masses through a simple quantum field theoretic mechanism. I clarify that the quantity…
We review the gauged quintessence scenario, wherein the quintessence scalar field responsible for dark energy is promoted to a complex field charged under a dark $U(1)$ gauge symmetry. This construction leads to new and potentially rich…
It is shown that quantum vacuum fluctuations give rise to a curvature of space-time of the order appropriate to explain the observed accelerated expansion of the universe. The fact that the fluctuations produce curvature, even if the…
We investigate in this paper the cosmological evolution of a dark energy model with two scalar fields where one of the scalar has canonical kinetic energy and another scalar has negative kinetic energy term. For such a system with…
We address issues on the origin of gravity and the dark energy (or the cosmological constant) from the perspectives of emergent gravity. We discuss how the emergent gravity reveals a noble, radically different picture about the origin of…
We present an approach to the problem of vacuum energy in cosmology, based on dynamical screening of Lambda on the horizon scale. We review first the physical basis of vacuum energy as a phenomenon connected with macroscopic boundary…
The physical nature of the presently dominating enigmatic dark energy in the expanding universe is demonstrated to be explainable as an excess of the kinetic energy with respect to its potential energy. According to traditional Friedman…
The archetypal model for the recently discovered dark energy component of the universe is based on the existence of a scalar field whose dynamical evolution comes down today to a non-vanishing cosmological constant. In the past - before…
We present cosmological perturbation theory in neutrino probe interacting dark-energy models, and calculate cosmic microwave background anisotropies and matter power spectrum. In these models, the evolution of the mass of neutrinos is…
Current cosmological data seem to show that dark energy is evolving in time and that it possibly crossed the phantom divide in the past. So far the only theories that lead to such a behavior involve a non-trivial coupling between dark…
We investigate whether interaction between massive neutrinos and quintessence scalar field is the origin of the late time accelerated expansion of the universe. We present cosmological perturbation theory in neutrinos probe interacting…
We consider a local phenomenological model to explain a non-local gravity scenario which has been proposed to address dark energy issues. This non-local gravity action has been seen to fit the data as well as $\Lambda$-CDM and therefore…
We studied the dilaton cosmology based on Weyl-Scaled induced gravity. The potential of dilaton field is taken as exponential form. An analytical solution of Einstein equation is found. The dilaton can be a candidate for dark energy that…
The modified F(R)-scalar-Gauss-Bonnet gravity is proposed as dark energy model. The reconstruction program for such theory is developed. It is explicitly demonstrated that the known classical universe expansion history (deceleration epoch,…
We perform a detailed dynamical analysis of the teleparallel dark energy scenario, which is based on the teleparallel equivalent of General Relativity, in which one adds a canonical scalar field, allowing also for a nonminimal coupling with…