Related papers: Dark Matter Gravitational Clustering With a Long-R…
In a cosmological model with a chiral symmetry, there are two, dynamically-related spin-zero fields, a scalar $\phi$ and a pseudoscalar $b$. These fields have self-interactions. Spontaneous symmetry breaking results in a very massive scalar…
We implement an adaptation of the COLA approach, a hybrid scheme that combines Lagrangian perturbation theory with an N-body approach, to model non-linear collapse in chameleon and symmetron modified gravity models. Gravitational screening…
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…
Mc Gaugh et al. (2016) have found, by investigating a large sample of Spirals, a tight non linear relationship between the total radial acceleration, connected with the Dark Matter phenomenon, and its component which comes from the…
In two recent papers, we developed a powerful technique to link the distribution of galaxies to that of dark matter haloes by considering halo occupation numbers as function of galaxy luminosity and type. In this paper we use these…
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…
Recent high-quality observations of dwarf and low surface brightness (LSB) galaxies have shown that their dark matter (DM) halos prefer flat central density profiles. On the other hand the standard cold dark matter model simulations predict…
The decay and annihilation cross sections of dark matter particles may depend on the value of a chameleonic scalar field that both evolves cosmologically and takes different values depending on the local matter density. This possibility…
In this thesis, we investigate the possibility that dark matter consists of ultra light spin-zero particles with mass $m \sim 10^{-22}\ \text{eV}$. We focus on the role of self-interactions, assuming all other non-gravitational couplings to…
Self-interacting dark matter is known as one of the most appropriate candidates for dark matter. Due to its excellent success in removing many astrophysical problems, particularly in small scale structure, studying this model has taken on…
Providing accurate predictions for the spatial distribution of matter and luminous tracers in the presence of massive neutrinos is an important task, given the imminent arrival of highly accurate large-scale structure observations. In this…
The use of parallel computers and increasingly sophisticated software has allowed us to perform a large suite of N-body simulations using from $10^8$,to $10^9$ particles. We will report on our recent convergence tests of the halo mass…
Interactions between dark matter (DM) and radiation (photons or neutrinos) in the early Universe suppress density fluctuations on small mass scales. Here we perform a thorough analysis of structure formation in the fully non-linear regime…
If the accelerated expansion of the Universe at the present epoch is driven by a dark energy scalar field, there may well be a non-trivial coupling between the dark energy and the cold dark matter (CDM) fluid. Such interactions give rise to…
The recent observational evidence for the current cosmic acceleration have stimulated renewed interest in alternative cosmologies, such as scenarios with interaction in the dark sector (dark matter and dark energy). In general, such models…
Strong gravitational lensing offers a powerful probe of the detailed distribution of matter in lenses, while magnifying and bringing faint background sources into view. Observed strong lensing by massive galaxy clusters, which are often in…
Many models of dark matter include self-interactions beyond gravity. A variety of astrophysical observations have previously been used to place limits on the strength of such self-interactions. However, previous works have generally focused…
We use high-resolution simulations of large-scale structure formation to analyze the effects of interacting dark matter and dark energy on the evolution of the halo mass function. Using a chi-square likelihood analysis, we find significant…
We investigate the effects of dark scalar- and vector-mediated interactions on dark matter admixed neutron stars, employing the two-fluid formalism. We adopt three different nuclear equations of state -- BSk22, MPA1 and APR4 -- to describe…
The galaxy correlation function serves as a fundamental tool for studying cosmology, galaxy formation, and the nature of dark matter. It is well established that more massive, redder and more compact galaxies tend to have stronger…