Related papers: A unified solution to the small scale problems of …
We model in simple terms the angular momentum (J) problem of galaxy formation in CDM, and identify the key elements of a scenario that can solve it. The buildup of J is modeled via dynamical friction and tidal stripping in mergers. This…
The structural evolution of substructure in cold dark matter (CDM) models is investigated combining ``low-resolution'' satellites from cosmological N-body simulations of parent halos with N=10^7 particles with high-resolution individual…
Dwarf spheroidal galaxies provide well-known challenges to the standard cold and collisionless dark matter scenario: The too-big-to-fail problem, namely the mismatch between the observed mass enclosed within the half-light radius of dwarf…
Observations on galactic scales seem to be in contradiction with recent high resolution N-body simulations. This so-called cold dark matter (CDM) crisis has been addressed in several ways, ranging from a change in fundamental physics by…
In cosmological N-body simulations, the baryon effects on the cold dark matter (CDM) halos can be used to solve the small scale problems in $\Lambda$CDM cosmology, such as cusp-core problem and missing satellites problem. It turns out that…
We study three cosmological hydrodynamical simulations of Milky Way(MW)-sized halos including a comparison with the dark matter(DM)-only counterparts. We find one of our simulated galaxies with interesting MW-like features. Thanks to a…
The amplitude of large-scale matter fluctuations inferred from the observed Sunyaev-Zeldovich (SZ) cluster mass function and from weak gravitational lensing studies, when taken at face value, is in tension with measurements of the cosmic…
The cold dark matter (CDM) cosmological model has been remarkably successful in explaining cosmic structure over an enormous span of redshift, but it has faced persistent challenges from observations that probe the innermost regions of dark…
Dwarf spheroidal galaxies (dSphs) are extremely gas-poor, dark matter-dominated galaxies, which make them ideal to test the predictions of the cold dark matter (CDM) model. We argue that the removal of the baryonic component from gas-rich…
We revisit the possibility of using cosmological observations to constrain models that involve interactions between neutrinos and dark matter. We show that small-scale measurements of the cosmic microwave background with a few per cent…
We study cluster mass dark matter haloes, their progenitors and surroundings in an coupled Dark Matter-Dark Energy model and compare it to quintessence and $\Lambda$CDM models with adiabatic zoom simulations. When comparing cosmologies with…
We review theories of dark matter (DM) beyond the collisionless paradigm, known as self-interacting dark matter (SIDM), and their observable implications for astrophysical structure in the Universe. Self-interactions are motivated, in part,…
Dwarf galaxy abundances can serve as discernment tests for models of structure formation. Previous small-scale tensions between observations and dark matter-only cosmological simulations may have been resolved with the inclusion of baryonic…
Using high resolution cosmological hydrodynamical simulations of Milky Way-massed disk galaxies, we demonstrate that supernovae feedback and tidal stripping lower the central masses of bright (-15 < M_V < -8) satellite galaxies. These…
Recent studies have presented evidence for tension between the constraints on Omega_m and sigma_8 from the cosmic microwave background (CMB) and measurements of large-scale structure (LSS). This tension can potentially be resolved by…
We use high resolution cosmological simulations of Milky Way-mass galaxies that include both baryons and dark matter to show that baryonic physics (energetic feedback from supernovae and subsequent tidal stripping) significantly reduces the…
The $\Lambda$CDM model, or concordance cosmology, as it is often called, is a paradigm at its maturity. It is clearly able to describe the universe at large scale, even if some issues remain open, such as the cosmological constant problem ,…
Cold Dark Matter with a large cosmological constant (LambdaCDM) appears to fit large scale structure observations well. Of the possible small scale problems, the Central Cusps and Too Many Satellites problems now appear to be at least…
Twenty years ago, the mismatch between the observed number of Milky Way satellite galaxies and the predicted number of cold dark matter (CDM) subhalos was dubbed the ``missing satellites problem". Although mostly framed since in terms of…
While the behavior of the dominant component of the dark matter is reasonably well established by cosmological observables, its particle nature and interactions with the rest of the matter are not known. We consider three dark matter models…