Related papers: Origin of the Cosmological Constant
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 have studied a cosmological model with a cosmological term of the form $\Lambda=3\alpha\fr{\dot R^2}{R^2}+\bt\fr{\ddot R}{R}+\fr{3\gamma}{R^2} \alpha, \ \bt \gamma$ are constants. The scale factor (R) is found to vary linearly with time…
Increasing improvements in the independent determinations of the Hubble constant and the age of the universe now seem to indicate that we need a small non-vanishing cosmological constant to make the two independent observations consistent…
The energy densities of matter and the vacuum are currently observed to be of the same order of magnitude: $(\Omega_{m 0} \approx 0.3) \sim (\Omega_{\Lambda 0} \approx 0.7)$. The cosmological window of time during which this occurs is…
Models of the very early universe, including inflationary models, are argued to produce varying universe domains with different values of fundamental constants and cosmic parameters. Using the cosmological hydrodynamical simulation code…
Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and…
The present standard model of cosmology, $\Lambda$CDM, contains some intriguing coincidences. Not only are the dominant contributions to the energy density approximately of the same order at the present epoch, but we note that contrary to…
We investigate the role of the cosmological constant in the holographic description of a radiation-dominated universe $C_2/R^4$ with a positive cosmological constant $\Lambda$. In order to understand the nature of cosmological term, we…
The current acceleration of the universe can be modeled in terms of a cosmological constant. We show that the extremely small value of \Lambda L_P^2 ~ 3.4 x 10^{-122}, the holy grail of theoretical physics, can be understood in terms of a…
The age of the Universe in the $\Lambda$CDM cosmology with $\Omega_{matter}=0.26$ and $\Omega_{\Lambda}=0.74$ is the same as in the Milne cosmology which correspods to an almost empty universe. In both cases it is a reciprocal Hubble…
The discovery that the expansion of the universe is accelerating in time is a major discovery which still awaits adequate explanation. It is generally agreed that this implies a cosmic repulsion as a result of the existence of a…
A simple model is introduced in which the cosmological constant is interpreted as a true Casimir effect on a scalar field filling the universe (e.g. $\mathbf{R} \times \mathbf{T}^p\times \mathbf{T}^q$, $\mathbf{R} \times \mathbf{T}^p\times…
The principles of General Relativity allow for a non-vanishing cosmological constant, which can possibly be interpreted at least partially in terms of quantum-fluctuations of matter fields. Depending on sign and magnitude it can cause…
I start by defining the cosmological parameters $H_0, \Omega_m$ and $\Omega_\Lambda$. Then I show how the age of the universe depends on them, followed by the evolution of the scale parameter of the universe for various values of the…
The discussion of cosmological parameters used to be a source of embarrassment to cosmologists. Today, measurements of the cosmological parameters are leading the way into the era of precision cosmology. The CMB temperature is measured to…
We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru-Kallosh-Linde-Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density,…
In this work a satisfactory, simple theoretical prediction of the data corresponding to observationally (by fine tuning condition) estimated value of the cosmological constant is given. It is supposed (in conceptually analogy with…
We construct the cosmological model to explain the cosmological constant problem. We built the extension of the standard cosmological model $\Lambda$CDM by consideration of decaying vacuum energy represented by the running cosmological…
Most of the calculations done to obtain the value of the cosmological constant use methods of quantum gravity, a theory that has not been established as yet, and a variety of results are usually obtained. The numerical value of the…
We show that the cosmological constant appears as a Lagrange multiplier if nature is described by a canonical noncommutative spacetime. It is thus an arbitrary parameter unrelated to the action and thus to vacuum fluctuations. The…