Related papers: Cosmological constant problems and their solutions
An anthropic understanding of the cosmological constant requires that the vacuum energy at late time scans from one patch of the universe to another. If the vacuum energy during inflation also scans, the various patches of the universe…
After reviewing the cosmological constant problem - why is Lambda not huge? - I outline the two basic approaches that had emerged by the late 1980s, and note that each made a clear prediction. Precision cosmological experiments now indicate…
We study the role of the cosmological constant (CC) as a component of dark energy (DE). It is argued that the cosmological term is in general unavoidable and it should not be ignored even when dynamical DE sources are considered. From the…
We study a mechanism, inspired from the mechanism for generating the gauge hierarchy in Randall-Sundrum model, to investigate the cosmological constant problem. First we analyze the bulk cosmological constant and brane vacuum energies in RS…
The accelerating expansion of the Universe points to a small positive vacuum energy density and negative vacuum pressure. A strong candidate is the cosmological constant in Einstein's equations of General Relativity. The vacuum dark energy…
The old cosmological-constant (CC) problem indicates an inconsistency of the usual formulation of semiclassical gravity. The usual formulation of semiclassical gravity also seems to be inconsistent with the conventional interpretation of…
It is shown that in the theory of discrete quantum gravity the cosmological constant problem can be solved due to the phenomena of elliptic operators spectrum "loosening" and universe inflation.
There appears to be no natural explanation for the cosmological constant's small size within the framework of local relativistic field theories. We argue that the recently-discussed framework for which the observable universe is identified…
A modified-gravity-type model of two hypothetical massless vector fields is presented. These vector fields are gravitationally coupled to standard matter and an effective cosmological constant. Considered in a cosmological context, the…
In this paper we provide both a diagnosis and resolution of the cosmological constant problem, one in which a large (as opposed to a small) cosmological constant $\Lambda$ can be made compatible with observation. We trace the origin of the…
We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future…
In this paper, we give a possible solution to the cosmological constant problem. It is shown hat the traditional approach, based on volume weighting of probabilities, leads to an incoherent onclusion: the probability that a randomly chosen…
If the fine structure constant $\alpha =e^2/(\hbar c)$ were to change, then a number of interpretations would be possible, attributing this change either to variations in the electron charge, the dielectric constant of the vacuum, the speed…
We show that the presence of a temporal electromagnetic field on cosmological scales generates an effective cosmological constant which can account for the accelerated expansion of the universe. Primordial electromagnetic quantum…
We propose that the solution to the cosmological vacuum energy puzzle may come from the infrared sector of the effective theory of gravity, where the impact of the trace anomaly is of upmost relevance. We proceed by introducing two…
A mechanism is introduced to reduce a large cosmological constant to a sufficiently small value consistent with observational upper limit. The basic ingradient in this mechanism is a distinction which has been made between the two unit…
The universe appears to be accelerating, but the reason why is a complete mystery. The simplest explanation, a small vacuum energy (cosmological constant), raises three difficult issues: why the vacuum energy is so small, why it is not…
We discuss the influence of the cosmological constant on the gravitational equations of motion of bodies with arbitrary masses and eventually solve the two-body problem. Observational constraints are derived from measurements of the…
The stability of cosmological solutions in the recently suggested specific mechanism of dynamical compensation of vacuum energy is studied. It is found that the solutions in the original version lead to cosmological singularity which could…
An additional variation of the Einstein-Hilbert action with respect to the Planck mass provides a constraint on the average Ricci scalar that prevents vacuum energy from gravitating. Consideration of the evolution of the inhomogeneous…