Related papers: Invisible QCD as Dark Energy
A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic…
A model of unified dark matter and dark energy based on a Dynamical Spacetime Theory (DST) is studied. By introducing a Dynamical Spacetime vector field $\chi_\mu$, a conservation of an energy momentum tensor $T^{\mu\nu}_{(\chi)}$ emerges.…
Standard cosmology poses a number of important questions. Apart from its singular origin, it possesses early and late accelerating phases required to account for observations. The vacuum energy has been considered as a possible way to…
We propose a new dark energy model for solving the cosmological fine-tuning and coincidence problems. A default assumption is that the fine-tuning problem disappears if we do not interpret dark energy as vacuum energy. The key idea to…
We show that the phase transition from the decelerating universe to the accelerating universe, which is of relevance to the cosmological coincidence problem, is possible in the semiclassically quantized two-dimensional dilaton gravity by…
We consider the fate of the observable universe in the light of the discovery of a dark energy component to the cosmic energy budget. We extend results for a cosmological constant to a general dark energy component and examine the…
The Higgs-Dilaton cosmological model is able to describe simultaneously an inflationary expansion in the early Universe and a dark energy dominated stage responsible for the present day acceleration. It also leads to a non-trivial relation…
We investigate the clustering properties of a dynamical dark energy component. In a cosmic mix of a pressureless fluid and a light scalar field, we follow the linear evolution of spherical matter perturbations. We find that the scalar field…
If the preon structure of quarks, leptons and gauge bosons will be proved then in the Universe during a relativistic phase transition the production of nonperturbative preon condensates has occured. Familons are collective excitations of…
Axion-like fields are naturally generated by a mechanism of anomaly cancellation of one or more anomalous gauge abelian symmetries at the Planck scale, emerging as duals of a two-form from the massless bosonic sector of string theory. This…
The nonequilibrium dynamics of the chiral phase transition expected during the expansion of the quark-qluon plasma produced in a high energy hadron or heavy ion collision is studied in the O(4) linear sigma model to leading order in a large…
Asymmetric dark matter is a well-motivated approach to explain the apparent coincidence between the relic densities of visible and dark matter, $\Omega_D \simeq 5.4\Omega_b$. A complete explanation requires two components, a relation…
It is demonstrated that dark energy, driven by tachyons having non-minimal coupling with curvature and self-interacting inverse cubic potential, decays to cold dark matter in the late universe. It is found that this penomenon yields a…
A unified dynamical model of dark energy and inflation is presented, in which both phenomena are driven by axion-like fields-quintessences-of spontaneously broken global $U(1)_A$'s symmetries whose potentials are induced by instantons of…
The discovery ten years ago that the expansion of the Universe is accelerating put in place the present cosmological model, in which the Universe is composed of 4% baryons, 20% dark matter, and 76% dark energy. Yet the underlying cause of…
A QED-based symmetry breaking/bootstrap mechanism, appearing at sufficiently small space-time distances, is suggested as an explanation for the vacuum energy that furnished the initial impulse for Inflation, and continues on, to the present…
QCD is the fundamental theory to describe the strong interaction, where quarks and gluons have the color degrees of freedom. However, a single quark or gluon can not be separated out and all observable particles are color singlet states.…
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 present a new mechanism for cosmic acceleration consisting of a scalar field coupled to a triplet of classical U(1) gauge fields. The gauge fields are arranged in a homogeneous, isotropic configuration, with both electric- and…
Along with compacting baryon (neutron) spacing, two very important factors come into play at once: the lack of self-stabilization within a compact neutron star (NS) associated with possible black hole (BH) horizon appearance and the phase…