Related papers: Local Group galaxies emerge from the dark
For almost two decades the properties of "dwarf" galaxies have challenged the Cold Dark Matter (CDM) paradigm of galaxy formation. Most observed dwarf galaxies consists of a rotating stellar disc embedded in a massive DM halo with a near…
We present a detailed comparison of a Local Group dwarf galaxy analogue evolved in two cosmological models: the standard $\Lambda$CDM and a self-interacting dark matter (SIDM) model with a velocity-dependent cross-section. Both simulations…
The concordance Cold Dark Matter model for the formation of structure in the Universe, while remarkably successful at describing observations on large scales, has a number of problems on galaxy scales. The Milky Way and its satellite system…
The concordance cosmological model based on cold dark matter makes definitive predictions for the growth of galaxies in the Universe, which are being actively studied using numerical simulations. These predictions appear to contradict the…
We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments (FIRE) physics to both Local Group (LG)-like and isolated Milky Way (MW)-like volumes (ten host systems…
Galaxies of different types are not equally distributed in the Local Universe. In particular, the supergalactic plane is prominent among the brightest ellipticals, but inconspicuous among the brightest disk galaxies. This striking…
We investigate the population of bright satellites ($M_{*} \geq 10^{5} \mathrm{M}_{\odot}$) of haloes of mass comparable to that of the Milky Way in cosmological simulations in which the dark matter (DM) is either cold, warm or…
We use a pair of high resolution N-body simulations implementing two dark matter models, namely the standard cold dark matter (CDM) cosmogony and a warm dark matter (WDM) alternative where the dark matter particle is a 1.5keV thermal relic.…
We study galaxy formation in sterile neutrino dark matter models that differ signifi- cantly from both cold and from `warm thermal relic' models. We use the EAGLE code to carry out hydrodynamic simulations of the evolution of pairs of…
Dwarf galaxies in groups of galaxies provide excellent test cases for models of structure formation. This led to a so-called small-scale crisis, including the famous missing satellite and too-big-to-fail problems. It was suggested that…
(Abridged) The existence of exotic dark matter particles outside the standard model of particle physics constitutes a central hypothesis of the current standard model of cosmology (SMoC). Using a wide range of observational data I outline…
In this work, we present results for the photometric and clustering properties of galaxies that arise in a LambdaCDM hydrodynamical simulation of the local universe. The present-day distribution of matter was constructed to match the…
A critical challenge to the cold dark matter (CDM) paradigm is that there are fewer satellites observed around the Milky Way than found in simulations of dark matter substructure. We show that there is a match between the observed satellite…
The nature of the dark matter can affect the collapse time of dark matter haloes, and can therefore be imprinted in observables such as the stellar population ages and star formation histories of dwarf galaxies. In this paper we use high…
We review theoretical approaches to the study of galaxy formation, with emphasis on the role of hydrodynamic simulations in modeling the high redshift galaxy population. We present new predictions for the abundance of star-forming galaxies…
We present an analysis of the ellipticities of galaxy groups, derived from the spatial distribution of member galaxies, revealing a notable incongruity between the observed local galaxy groups and their counterparts in the Lambda cold dark…
The Lambda-Cold Dark Matter (LCDM) model agrees with most of the cosmological observations, but has some hindrances from observed data at smaller scales such as galaxies. Recently, Berezhiani and Khoury (2015) proposed a new theory…
We study the Local Group (LG) dwarf galaxy population predicted by the \apostle $\Lambda$CDM cosmological hydrodynamics simulations. These indicate that: (i)~the total mass within $3$ Mpc of the Milky Way-Andromeda midpoint ($M_{\rm 3Mpc}$)…
We present results from a pilot observation of nearby (~20 Mpc) galaxies with mass similar to that of the Milky Way (MW) to address the missing satellite problem. This is the first paper from an on-going project to address the problem with…
Dark galaxies are small, DM-dominated halos whose gas remains in hydrostatic and thermal equilibrium and has never formed stars. They are of particular interest because they represent a strong prediction of the LCDM model. As of today, only…