Related papers: There is No Missing Satellites Problem
We present a search for Galactic dark matter (DM) satellites using the Large Area Telescope (LAT). N-body simulations based on the Lambda-CDM model of cosmology predict a large number of as yet unobserved Galactic DM satellites. These…
Warm dark matter (WDM) has been proposed as an alternative to cold dark matter (CDM), to resolve issues such as the apparent lack of satellites around the Milky Way. Even if WDM is not the answer to observational issues, it is essential to…
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 revisit the Milky Way satellite problem using a semi-analytical model of galaxy formation and compare the predicted luminosity function to recent result from the SDSS. With cosmic photoionization, the luminosity function can be brought…
CDM simulations predict that there are hundreds of lumps of with masses greater than 10e7 solar masses in the Milky Way halo. However, we know of only a dozen dwarf satellites close to this mass. Are these lumps simply lacking in stars or…
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…
The concordance $\Lambda$CDM cosmology predicts tens of satellite galaxies distributed in the inner region ($<40\ \lkpc$) of the Milky Way (MW), yet at most $12$ were discovered at present day, including 3 discovered very recently by Dark…
One of the open questions in modern cosmology is the small scale crisis of the cold dark matter paradigm. Increasing attention has recently been devoted to self-interacting dark matter models as a possible answer. However, solving the…
We use a hybrid approach that combines high-resolution simulations of the formation of a Milky Way-like halo with a semi-analytic model of galaxy formation to study the mass content of dwarf galaxies in the concordance $\Lambda$CDM…
We develop a comprehensive and flexible model for the connection between satellite galaxies and dark matter subhalos in dark matter-only zoom-in simulations of Milky Way (MW)--mass host halos. We systematically identify the physical and…
The observed population of the Milky Way satellite galaxies offer a unique testing ground for galaxy formation theory on small-scales. Our novel approach was to investigate the clustering of the known Milky Way satellite galaxies and to…
The dark energy plus cold dark matter ($\Lambda$CDM) cosmological model has been a demonstrably successful framework for predicting and explaining the large-scale structure of Universe and its evolution with time. Yet on length scales…
Joint analyses of small-scale cosmological structure probes are relatively unexplored and promise to advance measurements of microphysical dark matter properties using heterogeneous data. Here, we present a multidimensional analysis of dark…
We investigate the spatial distribution of galactic satellites in high resolution simulations of structure formation in the LCDM model: the Aquarius dark matter simulations of individual halos and the Millennium II simulation of a large…
We quantify the detectability of stellar Milky Way satellites in the Sloan Digital Sky Survey (SDSS) Data Release 5. We show that the effective search volumes for the recently discovered SDSS--satellites depend strongly on their luminosity,…
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…
I explore several possible solutions to the ``missing satellites'' problem that challenges the collisionless cold dark matter model.
The Lambda Cold Dark Matter (LCDM) paradigm makes specific predictions for the abundance, structure, substructure and clustering of dark matter halos, the sites of galaxy formation. These predictions can be directly tested, in the low-mass…
We calculate the energy that baryons must inject in cold dark matter (CDM) haloes in order to remove centrally-divergent DM cusps on scales relevant to observations of dwarf spheroidal galaxies (dSphs). We estimate that the CDM haloes often…
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…