Related papers: Cosmology with a dynamically screened scalar inter…
We discuss the evolution of density perturbations of dark matter and dark energy in cosmological models which admit future singularities in a finite time. Up to now geometrical tests of the evolution of the universe do not differentiate…
Cold Dark Matter (CDM) has become the standard modern theory of cosmological structure formation. Its predictions appear to be in good agreement with data on large scales, and it naturally accounts for many properties of galaxies. But…
Well known scaling laws among the structural properties of the dark and the luminous matter in disc systems are too complex to be arisen by two inert components that just share the same gravitational field. This brings us to critically…
Studies of galaxy clusters have proved crucial in helping to establish the standard model of cosmology, with a universe dominated by dark matter and dark energy. A theoretical basis that describes clusters as massive, multi-component,…
(abridged) We continue the study of $\Lambda$SFDM cosmologies, which differ from $\Lambda$CDM in that CDM is replaced by scalar field dark matter (SFDM) by calculating the evolution of the background Universe, as well as linear…
We consider a toy model to analyze the consequences of dark matter interaction with a dark energy background on the overall rotation of galaxy clusters and the misalignment between their dark matter and baryon distributions when compared to…
We propose a general class of interacting models in which the interaction between the CDM component and $\Lambda$ is parameterized by an arbitrary function of the cosmic scale factor $\epsilon(a)$. Differently from other dynamical $\Lambda$…
Cosmological models involving an interaction between dark matter and dark energy have been proposed in order to solve the so-called coincidence problem. Different forms of coupling have been studied, but there have been claims that…
The idea of a negative-pressure dark energy component in the Universe which causes an accelerated expansion in the late Universe has deep implications in models of field theory and general relativity. In this article, we survey the evidence…
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…
The theory of the dynamical systems is a very complex subject which has brought several surprises in the recent past in connection with the theory of chaos and fractals. The application of the tools of the dynamical systems in cosmological…
We study the properties of voids in two different types of coupled scalar field theories. Due to the fifth force produced by the scalar field coupling, the matter particles feel stronger attraction amongst each other and cluster more…
It has long been recognized that tight relations link the mass, size, and characteristic velocity of galaxies. These scaling laws reflect the way in which baryons populate, cool, and settle at the center of their host dark matter halos; the…
These lecture notes aim to provide an introduction to dark matter from the perspective of astrophysics/cosmology. We start with a rapid overview of cosmology, including the evolution of the Universe, its thermal history and structure…
Numerical simulations are a versatile tool providing insight into the complicated process of structure formation in cosmology. This process is mainly governed by gravity, which is the dominant force on large scales. To date, a century after…
Constraints to the mass of a scalar field and the strength of its self-interacting coupling constant are obtained. This was done using observations of stellar dynamics at the center of our galaxy and by assuming that the dark compact object…
Six challenges for the standard cosmological model $\Lambda$CDM are listed, which arise when comparing theoretical predictions with observational data on scales of ~1 Mpc. Different parameters of luminous and dwarf galaxies in the local…
In this article, we examine a model which proposes a common explanation for the presence of additional attractive gravitational effects -- generally considered to be due to dark matter -- in galaxies and in clusters, and for the presence of…
Dark matter and dark energy are usually assumed to couple only gravitationally. An extension to this picture is to model dark energy as a scalar field coupled directly to cold dark matter. This coupling leads to new physical effects, such…
We consider scalar perturbations of energy--density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine--tuning for graceful exit, towards the standard Friedman eras of observed…