Related papers: Finite cosmology and a CMB cold spot
This paper deals with the cancellation mechanism, which identifies the energy density of space-time expansion in an empty universe with the zero-point energy density and avoids the scale discrepancy with the observed energy density…
The galaxy cluster power spectrum and mass/temperature functions are currently the most precise observational tools for constraining the theory of the formation of large scale structure (LSS) in the Universe. Complementing these tests by…
Observational constraints guide one forcefully to examine models in which the matter density is substantially less than critical density. Particularly noteworthy are those which are consistent with inflation. For these models, microwave…
Cosmological Voids are among the largest structures known in the universe with diameters ranging from 20 Mpc to 80 Mpc. In this paper I present a short review of the observational evidence and models so far proposed and a brief discussion…
We review the cosmological constraints put by the current CMB experiment including the recent ARCHEOPS data, in the framework of Lambda-CDM and quintessence paradigm. We show that well chosen combinations of constraints from different…
We demonstrate that as we extrapolate the current $\Lambda$CDM universe forward in time, all evidence of the Hubble expansion will disappear, so that observers in our "island universe" will be fundamentally incapable of determining the true…
The Universe on large scales is well described by the Lambda-CDM cosmological model. There however remain some heavy clouds on our global understanding, especially on galaxy scales, which we review here. While some of these clouds might…
We derive the redshift and the angular diameter distance in rotationless dust universes which are statistically homogeneous and isotropic, but have otherwise arbitrary geometry. The calculation from first principles shows that the…
We study a spatially flat Friedmann model containing a pressureless perfect fluid (dust) and a scalar field with an unbounded from below potential of the form $V(\fii)=W_0 - V_0\sinh(\sqrt{3/2}\kappa\fii)$, where the parameters $W_0$ and…
The cosmological constant $\Lambda$ is a free parameter in Einstein's equations of gravity. We propose to fix its value with a boundary condition: test particles should be free when outside causal contact, e.g. at infinity. Under this…
In this article we want to answer the cosmologically relevant question what, with some good semantic and physical reason, could be called the mass of an infinitely extended, homogeneously matter-filled and expanding universe. To answer this…
Astronomical observations strongly suggest that our universe is now accelerating and contains a substantial admixture of dark vacuum energy. Using numerical simulations to study this newly consolidated cosmological model (with a constant…
In this paper we have given a generalisation of the earlier work by Prigogine et al. who have constructed a phenomenological model of entropy production via particle creation in the very early universe generated out of the vacuum rather…
The present work describes an immersion in 5D of the interior Schwarzschild solution of the general relativity equations. The model theory is defined in the context of a flat 5D space time matter Minkowski model, using a Tolman like…
The astronomical observations indicate that the universe expands with acceleration and it has a finite event horizon. The recent CMB observations confirm the universe is homogeneous, isotropic and asymptotically flat. The total…
Over the last decades, observations with increasing quality have revolutionized our understanding of the general properties of the Universe. Questions posed for millenia by mankind about the origin, evolution and structure of the cosmos…
In this article, we review a series of recent theoretical results regarding a conventional approach to the dark energy (DE) concept. This approach is distinguished among others for its simplicity and its physical relevance. By compromising…
We note that the standard LCDM cosmological model continues to face fundamental problems. First, the model continues to depend wholly on two pieces of undiscovered physics, namely dark energy and cold dark matter. Then, the implied dark…
A simple and surprisingly realistic model of the origin of the universe can be developed using the Friedmann equation from general relativity, elementary quantum mechanics, and the experimental values of h, c, G and the proton mass. The…
As one of the fundamental unknowns of our Universe, the mass of dark matter remains to be a topic of great interest. We consider the possibility of a time-variation of the dark matter mass. We study the cosmological constraints on a model…