Related papers: Cosmological principle and honeycombs
We identify a new class of time periodic attractor solutions in scalar field cosmology, which we term Cosmological Frequency Combs (CFC). These solutions arise in exponential quintessence models with a phantom matter background and exhibit…
It is shown how the uncertainty principle can provide a mechanism for the generation of fluctuations of very diverse scales in the early universe. This phenomenon could account for the large-scale structure observed today.
We consider that the cosmological constant is associated with the vacuum energy density of a particle physics model. In the path integral formalism of euclidean quantum gravity and in the background of the Robertson Walker metric we…
We derive constraints on cosmological parameters using the power spectrum of galaxy clustering measured from the final two-degree field galaxy redshift survey (2dFGRS) and a compilation of measurements of the temperature power spectrum and…
We revise the statistical properties of the primordial cosmological density anisotropies that, at the time of matter radiation equality, seeded the gravitational development of large scale structures in the, otherwise, homogeneous and…
For two decades the hot big-bang model as been referred to as the standard cosmology -- and for good reason. For just as long cosmologists have known that there are fundamental questions that are not answered by the standard cosmology and…
The anthropic principle has been proposed as an explanation for the observed value of the cosmological constant. Here we revisit this proposal by allowing for variation between universes in the amplitude of the scale-invariant primordial…
Two fundamental empirical laws have been established in the analysis of galaxy space distribution. First, recent analyses have revealed that the three dimensional distribution of galaxies and clusters is characterized by large scale…
We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…
The large scale distribution of galaxies in the universe displays a complex pattern of clusters, super-clusters, filaments and voids with sizes limited only by the boundaries of the available samples. A quantitative statistical…
The combination of detections of anisotropy in the Cosmic Microwave Background radiation and observations of the large-scale distribution of galaxies probes the primordial density fluctuations of the universe on spatial scales varying by…
We present the results of analysis of constraints on cosmological parameters from cosmic microwave background (CMB) alone and in combination with galaxy cluster baryon fraction assuming inflation--generated adiabatic scalar fluctuations.…
On small scales the observable Universe is highly inhomogeneous, with galaxies and clusters forming a complex web of voids and filaments. The optical properties of such configurations can be quite different from the perfectly smooth…
We present a new version of holographic cosmology, which is compatible with present observations. A primordial $p=\rho$ phase of the universe is followed by a brief matter dominated era and a brief period of inflation, whose termination…
Thanks to new technology of observations and fresh inputs from particle physics, cosmology has advanced on both observational and theoretical fronts. It is therefore opportune that we take stock of the cosmological situation today and…
Cosmography is a phenomenological and relatively model-independent approach to cosmology, where physical quantities are expanded as a Taylor series in the cosmological redshift, or in related variables. Here we apply this methodology to…
We study the dynamics of the FLRW flat cosmological models in which the vacuum energy varies with time, $\Lambda(t)$. In this model we find that the main cosmological functions such as the scale factor of the universe and the Hubble flow…
Perhaps standard effective field theory arguments are right, and vacuum fluctuations really do generate a huge cosmological constant. I show that if one does not assume homogeneity and an arrow of time at the Planck scale, a very large…
Observational Cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and, more…
The structure formation in the local Universe is considered within the weak-field modification of General Relativity involving the cosmological constant. This approach enables to describe the dynamics of groups and clusters of galaxies, to…