Dark Energy as a Relic of the Vacuum-Energy Cancellation?

Details Dark Energy as a Relic of the Vacuum-Energy Cancellation? Dark Energy as a Relic of the Vacuum-Energy Cancellation?

2007-09-10

arxiv.org/abs/0709.1400v1

Int.J.Mod.Phys.D17:111-133,2008

Astronomy and Astrophysics

Astrophysics

General Relativity and Quantum Cosmology

24 pages, 2 figures, to appear on IJMPD

Scientific paper

10.1142/S0218271808011900

We analyze the dynamical implications of an exponential Lagrangian density for the gravitational field, as referred to an isotropic FRW Universe. Then, we discuss the features of the generalized deSitter phase, predicted by the new Friedmann equation. The existence of a consistent deSitter solution arises only if the ratio between the vacuum-energy density and that associated with the fundamental length of the theory acquires a tantalizing negative character. This choice allows us to explain the present universe dark energy as a relic of the vacuum-energy cancellation due to the cosmological constant intrinsically contained in our scheme. The corresponding scalar-tensor description of the model is addressed too, and the behavior of the scalar field is analyzed for both negative and positive values of the cosmological term. In the first case, the Friedmann equation is studied both in vacuum and in presence of external matter, while, in the second case, the quantum regime is approached in the framework of ''repulsive'' properties of the gravitational interaction, as described in recent issues in Loop Quantum Cosmology. In particular, in the vacuum case, we find a pure non-Einsteinian effect, according to which a negative cosmological constant provides an accelerating deSitter dynamics, in the region where the series expansion of the exponential term does not hold.

Affiliated with

Also associated with

No associations

Rating

Dark Energy as a Relic of the Vacuum-Energy Cancellation? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Dark Energy as a Relic of the Vacuum-Energy Cancellation?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dark Energy as a Relic of the Vacuum-Energy Cancellation? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-656297