Related papers: Pseudo-redundant vacuum energy
Possible analogies between vacuum state and quantum fluid provide a model to study vacuum energy density induced by thermal corrections, space-time curvature, boundary conditions and quantum back-reaction. We find that vacuum energy density…
We investigate Dark Energy by associating it with vacuum energy or Cosmological constant ${\Lambda}$ which is taken to be dynamic in nature. Our approach is phenomenological and falls within the domain of variable-$\Lambda$ Cosmology.…
The vacuum energy is computed for a scalar field in a noncommutative background in several models of noncommutative geometry. One may expect that the noncommutativity introduces a natural cutoff on the ultraviolet divergences of field…
One of the most important concepts in logic and the foundations of mathematics may be useful in providing an explanation for the cosmological constant problem. A connection between self-reference and consciousness has been previously…
The fact that the energy densities of dark energy and matter are similar currently, known as the coincidence problem, is one of the main unsolved problems of cosmology. We present here a model in which a spatial curvature of the universe…
We propose a model in which there exists a real scalar field $q$ satisfying a condition $\dot{q} =MH$ and its energy density is given by $(1/2)\dot{q}^2+V(q)$, where $H$ is the Hubble parameter ($H=\dot{a}/a$) and $M$ is a mass scale…
Dark energy in the universe is assumed to be vacuum energy. The energy-momentum of vacuum is described by a scale-dependent cosmological constant. The equations of motion imply for the density of matter (dust) the sum of the usual matter…
The accelerating expansion of the Universe points to a small positive value for the cosmological constant or vacuum energy density. We discuss recent ideas that the cosmological constant plus LHC results might hint at critical phenomena…
Many ambitious experiments have been proposed to constrain dark energy and detect its evolution. At present, observational constraints are consistent with a cosmological constant and there is no firm evidence for any evolution in the dark…
A finite vacuum energy density implies the existence of a UV scale for gravitational modes. This gives a phenomenological scale to the dynamical equations governing the cosmological expansion that must satisfy constraints consistent with…
Dark energy cosmology is considered in a modified Gauss-Bonnet model of gravity with and without a scalar field. It is shown that these generalizations of General Relativity endow it with a very rich cosmological structure: it may naturally…
Based on the analogy with superconductor physics we consider a scalar-vector-tensor gravitational model, in which the dark energy action is described by a gauge invariant electromagnetic type functional. By assuming that the ground state of…
We investigate a possible resolution of the dark energy problem within a pair-universe framework, in which the Universe emerges as an entangled pair of time-reversed sectors. In this setting, a global zero-energy condition allows vacuum…
A probable solution of the cosmological constant problem was recently found. We propose that dark energy of the Universe is vacuum energy. Our Universe during its expansion is spending its vacuum energy for creation of new quantum states,…
Cosmological constant a.k.a. dark energy problem is considered to be one major challenge in modern cosmology. Here we present a model where large scale structure formation causes spatially-flat FRW universe to fragment into numerous `FRW…
We propose the Gauss-Bonnet dark energy model inspired by string/M-theory where standard gravity with scalar contains additional scalar-dependent coupling with Gauss-Bonnet invariant. It is demonstrated that effective phantom (or…
We propose a cosmological model that makes a significant step toward solving the coincidence problem of the near similarity at the present of the dark energy and dark matter components. Our cosmology has the following properties: a) among…
I review the problem of dark energy focusing on the cosmological constant as the candidate and discuss its implications for the nature of gravity. Part 1 briefly overviews the currently popular `concordance cosmology' and summarises the…
Under the hypothesis that the cosmological constant vanishes in the true ground state with lowest possible energy density, we argue that the observed small but finite vacuum-like energy density can be explained if we consider a theory with…
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…