Related papers: Do Bound Structures Brake Cosmic Acceleration?
The self-gravitating gas in the Newtonian limit is studied in the presence of dark energy with a linear and constant equation of state. Entropy extremization associates to the isothermal Boltzmann distribution an effective density that…
We discuss the dynamics of a quintessence model involving two coupled scalar fields. The model presents two types of solutions, namely solutions that correspond to eternal and transient acceleration of the universe. In both cases, we obtain…
Recent cosmological data favour phantom-crossing dark energy, motivating models with non-minimal couplings that induce a fifth force on structure formation. Reconciling these models with local tests often requires strong screening, leading…
We explore the effects of dark matter and dark energy on the dynamical scaling properties of galaxy clusters. We investigate the cluster Faber-Jackson (FJ), Kormendy and Fundamental Plane (FP) relations between the mass, radius and velocity…
We study large-scale structure formation in the presence of a quintessence component with zero speed of sound in the framework of Eulerian Perturbation Theory. Due to the absence of pressure gradients, quintessence and dark matter are…
In a recent paper we considered the possibility of a scalar field providing an explanation for the cosmic acceleration. Our model had the interesting properties of attractor-like behavior and having its parameters of O(1) in Planck units.…
Changes in the values of the fundamental constants mu, the proton to electron mass ratio, and alpha, the fine structure constant due to rolling scalar fields have been discussed both in the context of cosmology and in new physics such as…
A quintessence scalar field or cosmon interacting with neutrinos can have important effects on cosmological structure formation. Within growing neutrino models the coupling becomes effective only in recent times, when neutrinos become…
We consider a cosmology in which dark matter and a quintessence scalar field responsible for the acceleration of the Universe are allowed to interact. Allowing for both conformal and disformal couplings, we perform a global analysis of the…
We study CMB constraints on a model with a cosmological constant and a fraction of dark matter non-minimally coupled to a massless scalar field. In this scenario, there is an extra gravity-like fifth force which can affect the evolution of…
A brief account of the current cosmological observations is given and their implications for QCDM and $\Lambda$CDM cosmologies are discussed. The nucleosynthesis and the galaxy formation constraints have been used to put limits on…
The most stringent bounds on the absolute neutrino mass scale come from cosmological data. These bounds are made possible because massive relic neutrinos affect the expansion history of the universe and lead to a suppression of matter…
The cosmological dynamics of minimally coupled scalar field that couple to the background matter with thermal interactions is investigated in exponential potential. The conditions for the existence and stability of various critical points…
We study the effect of the interaction between small scale clumps having velocities larger than the average escape velocity v_{\rm esc} and bound clumps (having v<v_{\rm esc}), on clusters of galaxies evolution. We find that the collapse of…
We discuss some cosmological consequences of a general model of coupled quintessence in which the phenomenological coupling between the cold dark matter and dark energy is a function of the cosmic scale factor $\epsilon(a)$. This class of…
In this paper, we analyse the effect of the expansion of the universe on the clustering of galaxies. We evaluate the configurational integral for interacting system of galaxies in an expanding universe by including effects produced by the…
Structure occurs over a vast range of scales in the universe. Our large-scale cosmological models are coarse-grained representations of what exists, which have much less structure than there really is. An important problem for cosmology is…
Scalar field dynamics may give rise to a nonzero cosmological variation of fundamental constants. Within different scenarios based on the unification of gauge couplings, the various claimed observations and bounds may be combined in order…
Nuclear systems are treated within a quantum statistical approach. Correlations and cluster formation are relevant for the properties of warm dense matter, but the description is challenging and different approximations are discussed. The…
We consider the cosmological evolution of a bulk scalar field and ordinary matter living on the brane world in the light of the constraints imposed by the matter dominated cosmological evolution and a small cosmological constant now. We…